Bug Summary

File:src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Support/Alignment.h
Warning:line 85, column 47
The result of the left shift is undefined due to shifting by '255', which is greater or equal to the width of type 'uint64_t'

Annotated Source Code

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clang -cc1 -cc1 -triple amd64-unknown-openbsd7.0 -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name DwarfCompileUnit.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -mrelocation-model pic -pic-level 1 -fhalf-no-semantic-interposition -mframe-pointer=all -relaxed-aliasing -fno-rounding-math -mconstructor-aliases -munwind-tables -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -fcoverage-compilation-dir=/usr/src/gnu/usr.bin/clang/libLLVM/obj -resource-dir /usr/local/lib/clang/13.0.0 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Analysis -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ASMParser -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/BinaryFormat -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Bitcode -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Bitcode -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Bitstream -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /include/llvm/CodeGen -I /include/llvm/CodeGen/PBQP -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/IR -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/IR -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/Coroutines -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ProfileData/Coverage -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo/CodeView -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo/DWARF -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo/MSF -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo/PDB -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Demangle -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ExecutionEngine -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ExecutionEngine/JITLink -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ExecutionEngine/Orc -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Frontend -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Frontend/OpenACC -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Frontend -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Frontend/OpenMP -I /include/llvm/CodeGen/GlobalISel -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/IRReader -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/InstCombine -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/Transforms/InstCombine -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/LTO -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Linker -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/MC -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/MC/MCParser -I /include/llvm/CodeGen/MIRParser -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Object -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Option -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Passes -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ProfileData -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/Scalar -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ADT -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Support -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo/Symbolize -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Target -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/Utils -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/Vectorize -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/IPO -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include -I /usr/src/gnu/usr.bin/clang/libLLVM/../include -I /usr/src/gnu/usr.bin/clang/libLLVM/obj -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include -D NDEBUG -D __STDC_LIMIT_MACROS -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D LLVM_PREFIX="/usr" -D PIC -internal-isystem /usr/include/c++/v1 -internal-isystem /usr/local/lib/clang/13.0.0/include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-comment -std=c++14 -fdeprecated-macro -fdebug-compilation-dir=/usr/src/gnu/usr.bin/clang/libLLVM/obj -ferror-limit 19 -fvisibility-inlines-hidden -fwrapv -D_RET_PROTECTOR -ret-protector -fno-rtti -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -fno-builtin-malloc -fno-builtin-calloc -fno-builtin-realloc -fno-builtin-valloc -fno-builtin-free -fno-builtin-strdup -fno-builtin-strndup -analyzer-output=html -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /home/ben/Projects/vmm/scan-build/2022-01-12-194120-40624-1 -x c++ /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp

/usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp

→
1//===- llvm/CodeGen/DwarfCompileUnit.cpp - Dwarf Compile Units ------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file contains support for constructing a dwarf compile unit.
10//
11//===----------------------------------------------------------------------===//
12
13#include "DwarfCompileUnit.h"
14#include "AddressPool.h"
15#include "DwarfExpression.h"
16#include "llvm/ADT/None.h"
17#include "llvm/ADT/STLExtras.h"
18#include "llvm/ADT/SmallString.h"
19#include "llvm/BinaryFormat/Dwarf.h"
20#include "llvm/CodeGen/AsmPrinter.h"
21#include "llvm/CodeGen/DIE.h"
22#include "llvm/CodeGen/MachineFunction.h"
23#include "llvm/CodeGen/MachineInstr.h"
24#include "llvm/CodeGen/MachineOperand.h"
25#include "llvm/CodeGen/TargetFrameLowering.h"
26#include "llvm/CodeGen/TargetRegisterInfo.h"
27#include "llvm/CodeGen/TargetSubtargetInfo.h"
28#include "llvm/IR/DataLayout.h"
29#include "llvm/IR/DebugInfo.h"
30#include "llvm/IR/GlobalVariable.h"
31#include "llvm/MC/MCSection.h"
32#include "llvm/MC/MCStreamer.h"
33#include "llvm/MC/MCSymbol.h"
34#include "llvm/MC/MCSymbolWasm.h"
35#include "llvm/MC/MachineLocation.h"
36#include "llvm/Target/TargetLoweringObjectFile.h"
37#include "llvm/Target/TargetMachine.h"
38#include "llvm/Target/TargetOptions.h"
39#include <iterator>
40#include <string>
41#include <utility>
42
43using namespace llvm;
44
45static dwarf::Tag GetCompileUnitType(UnitKind Kind, DwarfDebug *DW) {
46
47 // According to DWARF Debugging Information Format Version 5,
48 // 3.1.2 Skeleton Compilation Unit Entries:
49 // "When generating a split DWARF object file (see Section 7.3.2
50 // on page 187), the compilation unit in the .debug_info section
51 // is a "skeleton" compilation unit with the tag DW_TAG_skeleton_unit"
52 if (DW->getDwarfVersion() >= 5 && Kind == UnitKind::Skeleton)
53 return dwarf::DW_TAG_skeleton_unit;
54
55 return dwarf::DW_TAG_compile_unit;
56}
57
58DwarfCompileUnit::DwarfCompileUnit(unsigned UID, const DICompileUnit *Node,
59 AsmPrinter *A, DwarfDebug *DW,
60 DwarfFile *DWU, UnitKind Kind)
61 : DwarfUnit(GetCompileUnitType(Kind, DW), Node, A, DW, DWU), UniqueID(UID) {
62 insertDIE(Node, &getUnitDie());
63 MacroLabelBegin = Asm->createTempSymbol("cu_macro_begin");
64}
65
66/// addLabelAddress - Add a dwarf label attribute data and value using
67/// DW_FORM_addr or DW_FORM_GNU_addr_index.
68void DwarfCompileUnit::addLabelAddress(DIE &Die, dwarf::Attribute Attribute,
69 const MCSymbol *Label) {
70 // Don't use the address pool in non-fission or in the skeleton unit itself.
71 if ((!DD->useSplitDwarf() || !Skeleton) && DD->getDwarfVersion() < 5)
72 return addLocalLabelAddress(Die, Attribute, Label);
73
74 if (Label)
75 DD->addArangeLabel(SymbolCU(this, Label));
76
77 bool UseAddrOffsetFormOrExpressions =
78 DD->useAddrOffsetForm() || DD->useAddrOffsetExpressions();
79
80 const MCSymbol *Base = nullptr;
81 if (Label->isInSection() && UseAddrOffsetFormOrExpressions)
82 Base = DD->getSectionLabel(&Label->getSection());
83
84 if (!Base || Base == Label) {
85 unsigned idx = DD->getAddressPool().getIndex(Label);
86 addAttribute(Die, Attribute,
87 DD->getDwarfVersion() >= 5 ? dwarf::DW_FORM_addrx
88 : dwarf::DW_FORM_GNU_addr_index,
89 DIEInteger(idx));
90 return;
91 }
92
93 // Could be extended to work with DWARFv4 Split DWARF if that's important for
94 // someone. In that case DW_FORM_data would be used.
95 assert(DD->getDwarfVersion() >= 5 &&((void)0)
96 "Addr+offset expressions are only valuable when using debug_addr (to "((void)0)
97 "reduce relocations) available in DWARFv5 or higher")((void)0);
98 if (DD->useAddrOffsetExpressions()) {
99 auto *Loc = new (DIEValueAllocator) DIEBlock();
100 addPoolOpAddress(*Loc, Label);
101 addBlock(Die, Attribute, dwarf::DW_FORM_exprloc, Loc);
102 } else
103 addAttribute(Die, Attribute, dwarf::DW_FORM_LLVM_addrx_offset,
104 new (DIEValueAllocator) DIEAddrOffset(
105 DD->getAddressPool().getIndex(Base), Label, Base));
106}
107
108void DwarfCompileUnit::addLocalLabelAddress(DIE &Die,
109 dwarf::Attribute Attribute,
110 const MCSymbol *Label) {
111 if (Label)
112 DD->addArangeLabel(SymbolCU(this, Label));
113
114 if (Label)
115 addAttribute(Die, Attribute, dwarf::DW_FORM_addr, DIELabel(Label));
116 else
117 addAttribute(Die, Attribute, dwarf::DW_FORM_addr, DIEInteger(0));
118}
119
120unsigned DwarfCompileUnit::getOrCreateSourceID(const DIFile *File) {
121 // If we print assembly, we can't separate .file entries according to
122 // compile units. Thus all files will belong to the default compile unit.
123
124 // FIXME: add a better feature test than hasRawTextSupport. Even better,
125 // extend .file to support this.
126 unsigned CUID = Asm->OutStreamer->hasRawTextSupport() ? 0 : getUniqueID();
127 if (!File)
128 return Asm->OutStreamer->emitDwarfFileDirective(0, "", "", None, None,
129 CUID);
130 return Asm->OutStreamer->emitDwarfFileDirective(
131 0, File->getDirectory(), File->getFilename(), DD->getMD5AsBytes(File),
132 File->getSource(), CUID);
133}
134
135DIE *DwarfCompileUnit::getOrCreateGlobalVariableDIE(
136 const DIGlobalVariable *GV, ArrayRef<GlobalExpr> GlobalExprs) {
137 // Check for pre-existence.
138 if (DIE *Die = getDIE(GV))
139 return Die;
140
141 assert(GV)((void)0);
142
143 auto *GVContext = GV->getScope();
144 const DIType *GTy = GV->getType();
145
146 // Construct the context before querying for the existence of the DIE in
147 // case such construction creates the DIE.
148 auto *CB = GVContext ? dyn_cast<DICommonBlock>(GVContext) : nullptr;
149 DIE *ContextDIE = CB ? getOrCreateCommonBlock(CB, GlobalExprs)
150 : getOrCreateContextDIE(GVContext);
151
152 // Add to map.
153 DIE *VariableDIE = &createAndAddDIE(GV->getTag(), *ContextDIE, GV);
154 DIScope *DeclContext;
155 if (auto *SDMDecl = GV->getStaticDataMemberDeclaration()) {
156 DeclContext = SDMDecl->getScope();
157 assert(SDMDecl->isStaticMember() && "Expected static member decl")((void)0);
158 assert(GV->isDefinition())((void)0);
159 // We need the declaration DIE that is in the static member's class.
160 DIE *VariableSpecDIE = getOrCreateStaticMemberDIE(SDMDecl);
161 addDIEEntry(*VariableDIE, dwarf::DW_AT_specification, *VariableSpecDIE);
162 // If the global variable's type is different from the one in the class
163 // member type, assume that it's more specific and also emit it.
164 if (GTy != SDMDecl->getBaseType())
165 addType(*VariableDIE, GTy);
166 } else {
167 DeclContext = GV->getScope();
168 // Add name and type.
169 addString(*VariableDIE, dwarf::DW_AT_name, GV->getDisplayName());
170 if (GTy)
171 addType(*VariableDIE, GTy);
172
173 // Add scoping info.
174 if (!GV->isLocalToUnit())
175 addFlag(*VariableDIE, dwarf::DW_AT_external);
176
177 // Add line number info.
178 addSourceLine(*VariableDIE, GV);
179 }
180
181 if (!GV->isDefinition())
182 addFlag(*VariableDIE, dwarf::DW_AT_declaration);
183 else
184 addGlobalName(GV->getName(), *VariableDIE, DeclContext);
185
186 if (uint32_t AlignInBytes = GV->getAlignInBytes())
187 addUInt(*VariableDIE, dwarf::DW_AT_alignment, dwarf::DW_FORM_udata,
188 AlignInBytes);
189
190 if (MDTuple *TP = GV->getTemplateParams())
191 addTemplateParams(*VariableDIE, DINodeArray(TP));
192
193 // Add location.
194 addLocationAttribute(VariableDIE, GV, GlobalExprs);
195
196 return VariableDIE;
197}
198
199void DwarfCompileUnit::addLocationAttribute(
200 DIE *VariableDIE, const DIGlobalVariable *GV, ArrayRef<GlobalExpr> GlobalExprs) {
201 bool addToAccelTable = false;
202 DIELoc *Loc = nullptr;
203 Optional<unsigned> NVPTXAddressSpace;
204 std::unique_ptr<DIEDwarfExpression> DwarfExpr;
205 for (const auto &GE : GlobalExprs) {
206 const GlobalVariable *Global = GE.Var;
207 const DIExpression *Expr = GE.Expr;
208
209 // For compatibility with DWARF 3 and earlier,
210 // DW_AT_location(DW_OP_constu, X, DW_OP_stack_value) or
211 // DW_AT_location(DW_OP_consts, X, DW_OP_stack_value) becomes
212 // DW_AT_const_value(X).
213 if (GlobalExprs.size() == 1 && Expr && Expr->isConstant()) {
214 addToAccelTable = true;
215 addConstantValue(
216 *VariableDIE,
217 DIExpression::SignedOrUnsignedConstant::UnsignedConstant ==
218 *Expr->isConstant(),
219 Expr->getElement(1));
220 break;
221 }
222
223 // We cannot describe the location of dllimport'd variables: the
224 // computation of their address requires loads from the IAT.
225 if (Global && Global->hasDLLImportStorageClass())
226 continue;
227
228 // Nothing to describe without address or constant.
229 if (!Global && (!Expr || !Expr->isConstant()))
230 continue;
231
232 if (Global && Global->isThreadLocal() &&
233 !Asm->getObjFileLowering().supportDebugThreadLocalLocation())
234 continue;
235
236 if (!Loc) {
237 addToAccelTable = true;
238 Loc = new (DIEValueAllocator) DIELoc;
239 DwarfExpr = std::make_unique<DIEDwarfExpression>(*Asm, *this, *Loc);
240 }
241
242 if (Expr) {
243 // According to
244 // https://docs.nvidia.com/cuda/archive/10.0/ptx-writers-guide-to-interoperability/index.html#cuda-specific-dwarf
245 // cuda-gdb requires DW_AT_address_class for all variables to be able to
246 // correctly interpret address space of the variable address.
247 // Decode DW_OP_constu <DWARF Address Space> DW_OP_swap DW_OP_xderef
248 // sequence for the NVPTX + gdb target.
249 unsigned LocalNVPTXAddressSpace;
250 if (Asm->TM.getTargetTriple().isNVPTX() && DD->tuneForGDB()) {
251 const DIExpression *NewExpr =
252 DIExpression::extractAddressClass(Expr, LocalNVPTXAddressSpace);
253 if (NewExpr != Expr) {
254 Expr = NewExpr;
255 NVPTXAddressSpace = LocalNVPTXAddressSpace;
256 }
257 }
258 DwarfExpr->addFragmentOffset(Expr);
259 }
260
261 if (Global) {
262 const MCSymbol *Sym = Asm->getSymbol(Global);
263 if (Global->isThreadLocal()) {
264 if (Asm->TM.useEmulatedTLS()) {
265 // TODO: add debug info for emulated thread local mode.
266 } else {
267 // FIXME: Make this work with -gsplit-dwarf.
268 unsigned PointerSize = Asm->getDataLayout().getPointerSize();
269 assert((PointerSize == 4 || PointerSize == 8) &&((void)0)
270 "Add support for other sizes if necessary")((void)0);
271 // Based on GCC's support for TLS:
272 if (!DD->useSplitDwarf()) {
273 // 1) Start with a constNu of the appropriate pointer size
274 addUInt(*Loc, dwarf::DW_FORM_data1,
275 PointerSize == 4 ? dwarf::DW_OP_const4u
276 : dwarf::DW_OP_const8u);
277 // 2) containing the (relocated) offset of the TLS variable
278 // within the module's TLS block.
279 addExpr(*Loc,
280 PointerSize == 4 ? dwarf::DW_FORM_data4
281 : dwarf::DW_FORM_data8,
282 Asm->getObjFileLowering().getDebugThreadLocalSymbol(Sym));
283 } else {
284 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_GNU_const_index);
285 addUInt(*Loc, dwarf::DW_FORM_udata,
286 DD->getAddressPool().getIndex(Sym, /* TLS */ true));
287 }
288 // 3) followed by an OP to make the debugger do a TLS lookup.
289 addUInt(*Loc, dwarf::DW_FORM_data1,
290 DD->useGNUTLSOpcode() ? dwarf::DW_OP_GNU_push_tls_address
291 : dwarf::DW_OP_form_tls_address);
292 }
293 } else {
294 DD->addArangeLabel(SymbolCU(this, Sym));
295 addOpAddress(*Loc, Sym);
296 }
297 }
298 // Global variables attached to symbols are memory locations.
299 // It would be better if this were unconditional, but malformed input that
300 // mixes non-fragments and fragments for the same variable is too expensive
301 // to detect in the verifier.
302 if (DwarfExpr->isUnknownLocation())
303 DwarfExpr->setMemoryLocationKind();
304 DwarfExpr->addExpression(Expr);
305 }
306 if (Asm->TM.getTargetTriple().isNVPTX() && DD->tuneForGDB()) {
307 // According to
308 // https://docs.nvidia.com/cuda/archive/10.0/ptx-writers-guide-to-interoperability/index.html#cuda-specific-dwarf
309 // cuda-gdb requires DW_AT_address_class for all variables to be able to
310 // correctly interpret address space of the variable address.
311 const unsigned NVPTX_ADDR_global_space = 5;
312 addUInt(*VariableDIE, dwarf::DW_AT_address_class, dwarf::DW_FORM_data1,
313 NVPTXAddressSpace ? *NVPTXAddressSpace : NVPTX_ADDR_global_space);
314 }
315 if (Loc)
316 addBlock(*VariableDIE, dwarf::DW_AT_location, DwarfExpr->finalize());
317
318 if (DD->useAllLinkageNames())
319 addLinkageName(*VariableDIE, GV->getLinkageName());
320
321 if (addToAccelTable) {
322 DD->addAccelName(*CUNode, GV->getName(), *VariableDIE);
323
324 // If the linkage name is different than the name, go ahead and output
325 // that as well into the name table.
326 if (GV->getLinkageName() != "" && GV->getName() != GV->getLinkageName() &&
327 DD->useAllLinkageNames())
328 DD->addAccelName(*CUNode, GV->getLinkageName(), *VariableDIE);
329 }
330}
331
332DIE *DwarfCompileUnit::getOrCreateCommonBlock(
333 const DICommonBlock *CB, ArrayRef<GlobalExpr> GlobalExprs) {
334 // Construct the context before querying for the existence of the DIE in case
335 // such construction creates the DIE.
336 DIE *ContextDIE = getOrCreateContextDIE(CB->getScope());
337
338 if (DIE *NDie = getDIE(CB))
339 return NDie;
340 DIE &NDie = createAndAddDIE(dwarf::DW_TAG_common_block, *ContextDIE, CB);
341 StringRef Name = CB->getName().empty() ? "_BLNK_" : CB->getName();
342 addString(NDie, dwarf::DW_AT_name, Name);
343 addGlobalName(Name, NDie, CB->getScope());
344 if (CB->getFile())
345 addSourceLine(NDie, CB->getLineNo(), CB->getFile());
346 if (DIGlobalVariable *V = CB->getDecl())
347 getCU().addLocationAttribute(&NDie, V, GlobalExprs);
348 return &NDie;
349}
350
351void DwarfCompileUnit::addRange(RangeSpan Range) {
352 DD->insertSectionLabel(Range.Begin);
353
354 bool SameAsPrevCU = this == DD->getPrevCU();
355 DD->setPrevCU(this);
356 // If we have no current ranges just add the range and return, otherwise,
357 // check the current section and CU against the previous section and CU we
358 // emitted into and the subprogram was contained within. If these are the
359 // same then extend our current range, otherwise add this as a new range.
360 if (CURanges.empty() || !SameAsPrevCU ||
361 (&CURanges.back().End->getSection() !=
362 &Range.End->getSection())) {
363 CURanges.push_back(Range);
364 return;
365 }
366
367 CURanges.back().End = Range.End;
368}
369
370void DwarfCompileUnit::initStmtList() {
371 if (CUNode->isDebugDirectivesOnly())
372 return;
373
374 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
375 if (DD->useSectionsAsReferences()) {
376 LineTableStartSym = TLOF.getDwarfLineSection()->getBeginSymbol();
377 } else {
378 LineTableStartSym =
379 Asm->OutStreamer->getDwarfLineTableSymbol(getUniqueID());
380 }
381
382 // DW_AT_stmt_list is a offset of line number information for this
383 // compile unit in debug_line section. For split dwarf this is
384 // left in the skeleton CU and so not included.
385 // The line table entries are not always emitted in assembly, so it
386 // is not okay to use line_table_start here.
387 addSectionLabel(getUnitDie(), dwarf::DW_AT_stmt_list, LineTableStartSym,
388 TLOF.getDwarfLineSection()->getBeginSymbol());
389}
390
391void DwarfCompileUnit::applyStmtList(DIE &D) {
392 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
393 addSectionLabel(D, dwarf::DW_AT_stmt_list, LineTableStartSym,
394 TLOF.getDwarfLineSection()->getBeginSymbol());
395}
396
397void DwarfCompileUnit::attachLowHighPC(DIE &D, const MCSymbol *Begin,
398 const MCSymbol *End) {
399 assert(Begin && "Begin label should not be null!")((void)0);
400 assert(End && "End label should not be null!")((void)0);
401 assert(Begin->isDefined() && "Invalid starting label")((void)0);
402 assert(End->isDefined() && "Invalid end label")((void)0);
403
404 addLabelAddress(D, dwarf::DW_AT_low_pc, Begin);
405 if (DD->getDwarfVersion() < 4)
406 addLabelAddress(D, dwarf::DW_AT_high_pc, End);
407 else
408 addLabelDelta(D, dwarf::DW_AT_high_pc, End, Begin);
409}
410
411// Find DIE for the given subprogram and attach appropriate DW_AT_low_pc
412// and DW_AT_high_pc attributes. If there are global variables in this
413// scope then create and insert DIEs for these variables.
414DIE &DwarfCompileUnit::updateSubprogramScopeDIE(const DISubprogram *SP) {
415 DIE *SPDie = getOrCreateSubprogramDIE(SP, includeMinimalInlineScopes());
416
417 SmallVector<RangeSpan, 2> BB_List;
418 // If basic block sections are on, ranges for each basic block section has
419 // to be emitted separately.
420 for (const auto &R : Asm->MBBSectionRanges)
421 BB_List.push_back({R.second.BeginLabel, R.second.EndLabel});
422
423 attachRangesOrLowHighPC(*SPDie, BB_List);
424
425 if (DD->useAppleExtensionAttributes() &&
426 !DD->getCurrentFunction()->getTarget().Options.DisableFramePointerElim(
427 *DD->getCurrentFunction()))
428 addFlag(*SPDie, dwarf::DW_AT_APPLE_omit_frame_ptr);
429
430 // Only include DW_AT_frame_base in full debug info
431 if (!includeMinimalInlineScopes()) {
432 const TargetFrameLowering *TFI = Asm->MF->getSubtarget().getFrameLowering();
433 TargetFrameLowering::DwarfFrameBase FrameBase =
434 TFI->getDwarfFrameBase(*Asm->MF);
435 switch (FrameBase.Kind) {
436 case TargetFrameLowering::DwarfFrameBase::Register: {
437 if (Register::isPhysicalRegister(FrameBase.Location.Reg)) {
438 MachineLocation Location(FrameBase.Location.Reg);
439 addAddress(*SPDie, dwarf::DW_AT_frame_base, Location);
440 }
441 break;
442 }
443 case TargetFrameLowering::DwarfFrameBase::CFA: {
444 DIELoc *Loc = new (DIEValueAllocator) DIELoc;
445 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_call_frame_cfa);
446 addBlock(*SPDie, dwarf::DW_AT_frame_base, Loc);
447 break;
448 }
449 case TargetFrameLowering::DwarfFrameBase::WasmFrameBase: {
450 // FIXME: duplicated from Target/WebAssembly/WebAssembly.h
451 // don't want to depend on target specific headers in this code?
452 const unsigned TI_GLOBAL_RELOC = 3;
453 if (FrameBase.Location.WasmLoc.Kind == TI_GLOBAL_RELOC) {
454 // These need to be relocatable.
455 assert(FrameBase.Location.WasmLoc.Index == 0)((void)0); // Only SP so far.
456 auto SPSym = cast<MCSymbolWasm>(
457 Asm->GetExternalSymbolSymbol("__stack_pointer"));
458 // FIXME: this repeats what WebAssemblyMCInstLower::
459 // GetExternalSymbolSymbol does, since if there's no code that
460 // refers to this symbol, we have to set it here.
461 SPSym->setType(wasm::WASM_SYMBOL_TYPE_GLOBAL);
462 SPSym->setGlobalType(wasm::WasmGlobalType{
463 uint8_t(Asm->getSubtargetInfo().getTargetTriple().getArch() ==
464 Triple::wasm64
465 ? wasm::WASM_TYPE_I64
466 : wasm::WASM_TYPE_I32),
467 true});
468 DIELoc *Loc = new (DIEValueAllocator) DIELoc;
469 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_WASM_location);
470 addSInt(*Loc, dwarf::DW_FORM_sdata, TI_GLOBAL_RELOC);
471 if (!isDwoUnit()) {
472 addLabel(*Loc, dwarf::DW_FORM_data4, SPSym);
473 DD->addArangeLabel(SymbolCU(this, SPSym));
474 } else {
475 // FIXME: when writing dwo, we need to avoid relocations. Probably
476 // the "right" solution is to treat globals the way func and data
477 // symbols are (with entries in .debug_addr).
478 // For now, since we only ever use index 0, this should work as-is.
479 addUInt(*Loc, dwarf::DW_FORM_data4, FrameBase.Location.WasmLoc.Index);
480 }
481 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_stack_value);
482 addBlock(*SPDie, dwarf::DW_AT_frame_base, Loc);
483 } else {
484 DIELoc *Loc = new (DIEValueAllocator) DIELoc;
485 DIEDwarfExpression DwarfExpr(*Asm, *this, *Loc);
486 DIExpressionCursor Cursor({});
487 DwarfExpr.addWasmLocation(FrameBase.Location.WasmLoc.Kind,
488 FrameBase.Location.WasmLoc.Index);
489 DwarfExpr.addExpression(std::move(Cursor));
490 addBlock(*SPDie, dwarf::DW_AT_frame_base, DwarfExpr.finalize());
491 }
492 break;
493 }
494 }
495 }
496
497 // Add name to the name table, we do this here because we're guaranteed
498 // to have concrete versions of our DW_TAG_subprogram nodes.
499 DD->addSubprogramNames(*CUNode, SP, *SPDie);
500
501 return *SPDie;
502}
503
504// Construct a DIE for this scope.
505void DwarfCompileUnit::constructScopeDIE(
506 LexicalScope *Scope, SmallVectorImpl<DIE *> &FinalChildren) {
507 if (!Scope || !Scope->getScopeNode())
508 return;
509
510 auto *DS = Scope->getScopeNode();
511
512 assert((Scope->getInlinedAt() || !isa<DISubprogram>(DS)) &&((void)0)
513 "Only handle inlined subprograms here, use "((void)0)
514 "constructSubprogramScopeDIE for non-inlined "((void)0)
515 "subprograms")((void)0);
516
517 SmallVector<DIE *, 8> Children;
518
519 // We try to create the scope DIE first, then the children DIEs. This will
520 // avoid creating un-used children then removing them later when we find out
521 // the scope DIE is null.
522 DIE *ScopeDIE;
523 if (Scope->getParent() && isa<DISubprogram>(DS)) {
524 ScopeDIE = constructInlinedScopeDIE(Scope);
525 if (!ScopeDIE)
526 return;
527 // We create children when the scope DIE is not null.
528 createScopeChildrenDIE(Scope, Children);
529 } else {
530 // Early exit when we know the scope DIE is going to be null.
531 if (DD->isLexicalScopeDIENull(Scope))
532 return;
533
534 bool HasNonScopeChildren = false;
535
536 // We create children here when we know the scope DIE is not going to be
537 // null and the children will be added to the scope DIE.
538 createScopeChildrenDIE(Scope, Children, &HasNonScopeChildren);
539
540 // If there are only other scopes as children, put them directly in the
541 // parent instead, as this scope would serve no purpose.
542 if (!HasNonScopeChildren) {
543 FinalChildren.insert(FinalChildren.end(),
544 std::make_move_iterator(Children.begin()),
545 std::make_move_iterator(Children.end()));
546 return;
547 }
548 ScopeDIE = constructLexicalScopeDIE(Scope);
549 assert(ScopeDIE && "Scope DIE should not be null.")((void)0);
550 }
551
552 // Add children
553 for (auto &I : Children)
554 ScopeDIE->addChild(std::move(I));
555
556 FinalChildren.push_back(std::move(ScopeDIE));
557}
558
559void DwarfCompileUnit::addScopeRangeList(DIE &ScopeDIE,
560 SmallVector<RangeSpan, 2> Range) {
561
562 HasRangeLists = true;
563
564 // Add the range list to the set of ranges to be emitted.
565 auto IndexAndList =
566 (DD->getDwarfVersion() < 5 && Skeleton ? Skeleton->DU : DU)
567 ->addRange(*(Skeleton ? Skeleton : this), std::move(Range));
568
569 uint32_t Index = IndexAndList.first;
570 auto &List = *IndexAndList.second;
571
572 // Under fission, ranges are specified by constant offsets relative to the
573 // CU's DW_AT_GNU_ranges_base.
574 // FIXME: For DWARF v5, do not generate the DW_AT_ranges attribute under
575 // fission until we support the forms using the .debug_addr section
576 // (DW_RLE_startx_endx etc.).
577 if (DD->getDwarfVersion() >= 5)
578 addUInt(ScopeDIE, dwarf::DW_AT_ranges, dwarf::DW_FORM_rnglistx, Index);
579 else {
580 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
581 const MCSymbol *RangeSectionSym =
582 TLOF.getDwarfRangesSection()->getBeginSymbol();
583 if (isDwoUnit())
584 addSectionDelta(ScopeDIE, dwarf::DW_AT_ranges, List.Label,
585 RangeSectionSym);
586 else
587 addSectionLabel(ScopeDIE, dwarf::DW_AT_ranges, List.Label,
588 RangeSectionSym);
589 }
590}
591
592void DwarfCompileUnit::attachRangesOrLowHighPC(
593 DIE &Die, SmallVector<RangeSpan, 2> Ranges) {
594 assert(!Ranges.empty())((void)0);
595 if (!DD->useRangesSection() ||
596 (Ranges.size() == 1 &&
597 (!DD->alwaysUseRanges() ||
598 DD->getSectionLabel(&Ranges.front().Begin->getSection()) ==
599 Ranges.front().Begin))) {
600 const RangeSpan &Front = Ranges.front();
601 const RangeSpan &Back = Ranges.back();
602 attachLowHighPC(Die, Front.Begin, Back.End);
603 } else
604 addScopeRangeList(Die, std::move(Ranges));
605}
606
607void DwarfCompileUnit::attachRangesOrLowHighPC(
608 DIE &Die, const SmallVectorImpl<InsnRange> &Ranges) {
609 SmallVector<RangeSpan, 2> List;
610 List.reserve(Ranges.size());
611 for (const InsnRange &R : Ranges) {
612 auto *BeginLabel = DD->getLabelBeforeInsn(R.first);
613 auto *EndLabel = DD->getLabelAfterInsn(R.second);
614
615 const auto *BeginMBB = R.first->getParent();
616 const auto *EndMBB = R.second->getParent();
617
618 const auto *MBB = BeginMBB;
619 // Basic block sections allows basic block subsets to be placed in unique
620 // sections. For each section, the begin and end label must be added to the
621 // list. If there is more than one range, debug ranges must be used.
622 // Otherwise, low/high PC can be used.
623 // FIXME: Debug Info Emission depends on block order and this assumes that
624 // the order of blocks will be frozen beyond this point.
625 do {
626 if (MBB->sameSection(EndMBB) || MBB->isEndSection()) {
627 auto MBBSectionRange = Asm->MBBSectionRanges[MBB->getSectionIDNum()];
628 List.push_back(
629 {MBB->sameSection(BeginMBB) ? BeginLabel
630 : MBBSectionRange.BeginLabel,
631 MBB->sameSection(EndMBB) ? EndLabel : MBBSectionRange.EndLabel});
632 }
633 if (MBB->sameSection(EndMBB))
634 break;
635 MBB = MBB->getNextNode();
636 } while (true);
637 }
638 attachRangesOrLowHighPC(Die, std::move(List));
639}
640
641// This scope represents inlined body of a function. Construct DIE to
642// represent this concrete inlined copy of the function.
643DIE *DwarfCompileUnit::constructInlinedScopeDIE(LexicalScope *Scope) {
644 assert(Scope->getScopeNode())((void)0);
645 auto *DS = Scope->getScopeNode();
646 auto *InlinedSP = getDISubprogram(DS);
647 // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
648 // was inlined from another compile unit.
649 DIE *OriginDIE = getAbstractSPDies()[InlinedSP];
650 assert(OriginDIE && "Unable to find original DIE for an inlined subprogram.")((void)0);
651
652 auto ScopeDIE = DIE::get(DIEValueAllocator, dwarf::DW_TAG_inlined_subroutine);
653 addDIEEntry(*ScopeDIE, dwarf::DW_AT_abstract_origin, *OriginDIE);
654
655 attachRangesOrLowHighPC(*ScopeDIE, Scope->getRanges());
656
657 // Add the call site information to the DIE.
658 const DILocation *IA = Scope->getInlinedAt();
659 addUInt(*ScopeDIE, dwarf::DW_AT_call_file, None,
660 getOrCreateSourceID(IA->getFile()));
661 addUInt(*ScopeDIE, dwarf::DW_AT_call_line, None, IA->getLine());
662 if (IA->getColumn())
663 addUInt(*ScopeDIE, dwarf::DW_AT_call_column, None, IA->getColumn());
664 if (IA->getDiscriminator() && DD->getDwarfVersion() >= 4)
665 addUInt(*ScopeDIE, dwarf::DW_AT_GNU_discriminator, None,
666 IA->getDiscriminator());
667
668 // Add name to the name table, we do this here because we're guaranteed
669 // to have concrete versions of our DW_TAG_inlined_subprogram nodes.
670 DD->addSubprogramNames(*CUNode, InlinedSP, *ScopeDIE);
671
672 return ScopeDIE;
673}
674
675// Construct new DW_TAG_lexical_block for this scope and attach
676// DW_AT_low_pc/DW_AT_high_pc labels.
677DIE *DwarfCompileUnit::constructLexicalScopeDIE(LexicalScope *Scope) {
678 if (DD->isLexicalScopeDIENull(Scope))
679 return nullptr;
680
681 auto ScopeDIE = DIE::get(DIEValueAllocator, dwarf::DW_TAG_lexical_block);
682 if (Scope->isAbstractScope())
683 return ScopeDIE;
684
685 attachRangesOrLowHighPC(*ScopeDIE, Scope->getRanges());
686
687 return ScopeDIE;
688}
689
690/// constructVariableDIE - Construct a DIE for the given DbgVariable.
691DIE *DwarfCompileUnit::constructVariableDIE(DbgVariable &DV, bool Abstract) {
692 auto D = constructVariableDIEImpl(DV, Abstract);
693 DV.setDIE(*D);
694 return D;
695}
696
697DIE *DwarfCompileUnit::constructLabelDIE(DbgLabel &DL,
698 const LexicalScope &Scope) {
699 auto LabelDie = DIE::get(DIEValueAllocator, DL.getTag());
700 insertDIE(DL.getLabel(), LabelDie);
701 DL.setDIE(*LabelDie);
702
703 if (Scope.isAbstractScope())
704 applyLabelAttributes(DL, *LabelDie);
705
706 return LabelDie;
707}
708
709DIE *DwarfCompileUnit::constructVariableDIEImpl(const DbgVariable &DV,
710 bool Abstract) {
711 // Define variable debug information entry.
712 auto VariableDie = DIE::get(DIEValueAllocator, DV.getTag());
713 insertDIE(DV.getVariable(), VariableDie);
714
715 if (Abstract) {
716 applyVariableAttributes(DV, *VariableDie);
717 return VariableDie;
718 }
719
720 // Add variable address.
721
722 unsigned Index = DV.getDebugLocListIndex();
723 if (Index != ~0U) {
724 addLocationList(*VariableDie, dwarf::DW_AT_location, Index);
725 auto TagOffset = DV.getDebugLocListTagOffset();
726 if (TagOffset)
727 addUInt(*VariableDie, dwarf::DW_AT_LLVM_tag_offset, dwarf::DW_FORM_data1,
728 *TagOffset);
729 return VariableDie;
730 }
731
732 // Check if variable has a single location description.
733 if (auto *DVal = DV.getValueLoc()) {
734 if (!DVal->isVariadic()) {
735 const DbgValueLocEntry *Entry = DVal->getLocEntries().begin();
736 if (Entry->isLocation()) {
737 addVariableAddress(DV, *VariableDie, Entry->getLoc());
738 } else if (Entry->isInt()) {
739 auto *Expr = DV.getSingleExpression();
740 if (Expr && Expr->getNumElements()) {
741 DIELoc *Loc = new (DIEValueAllocator) DIELoc;
742 DIEDwarfExpression DwarfExpr(*Asm, *this, *Loc);
743 // If there is an expression, emit raw unsigned bytes.
744 DwarfExpr.addFragmentOffset(Expr);
745 DwarfExpr.addUnsignedConstant(Entry->getInt());
746 DwarfExpr.addExpression(Expr);
747 addBlock(*VariableDie, dwarf::DW_AT_location, DwarfExpr.finalize());
748 if (DwarfExpr.TagOffset)
749 addUInt(*VariableDie, dwarf::DW_AT_LLVM_tag_offset,
750 dwarf::DW_FORM_data1, *DwarfExpr.TagOffset);
751 } else
752 addConstantValue(*VariableDie, Entry->getInt(), DV.getType());
753 } else if (Entry->isConstantFP()) {
754 addConstantFPValue(*VariableDie, Entry->getConstantFP());
755 } else if (Entry->isConstantInt()) {
756 addConstantValue(*VariableDie, Entry->getConstantInt(), DV.getType());
757 } else if (Entry->isTargetIndexLocation()) {
758 DIELoc *Loc = new (DIEValueAllocator) DIELoc;
759 DIEDwarfExpression DwarfExpr(*Asm, *this, *Loc);
760 const DIBasicType *BT = dyn_cast<DIBasicType>(
761 static_cast<const Metadata *>(DV.getVariable()->getType()));
762 DwarfDebug::emitDebugLocValue(*Asm, BT, *DVal, DwarfExpr);
763 addBlock(*VariableDie, dwarf::DW_AT_location, DwarfExpr.finalize());
764 }
765 return VariableDie;
766 }
767 // If any of the location entries are registers with the value 0, then the
768 // location is undefined.
769 if (any_of(DVal->getLocEntries(), [](const DbgValueLocEntry &Entry) {
770 return Entry.isLocation() && !Entry.getLoc().getReg();
771 }))
772 return VariableDie;
773 const DIExpression *Expr = DV.getSingleExpression();
774 assert(Expr && "Variadic Debug Value must have an Expression.")((void)0);
775 DIELoc *Loc = new (DIEValueAllocator) DIELoc;
776 DIEDwarfExpression DwarfExpr(*Asm, *this, *Loc);
777 DwarfExpr.addFragmentOffset(Expr);
778 DIExpressionCursor Cursor(Expr);
779 const TargetRegisterInfo &TRI = *Asm->MF->getSubtarget().getRegisterInfo();
780
781 auto AddEntry = [&](const DbgValueLocEntry &Entry,
782 DIExpressionCursor &Cursor) {
783 if (Entry.isLocation()) {
784 if (!DwarfExpr.addMachineRegExpression(TRI, Cursor,
785 Entry.getLoc().getReg()))
786 return false;
787 } else if (Entry.isInt()) {
788 // If there is an expression, emit raw unsigned bytes.
789 DwarfExpr.addUnsignedConstant(Entry.getInt());
790 } else if (Entry.isConstantFP()) {
791 APInt RawBytes = Entry.getConstantFP()->getValueAPF().bitcastToAPInt();
792 DwarfExpr.addUnsignedConstant(RawBytes);
793 } else if (Entry.isConstantInt()) {
794 APInt RawBytes = Entry.getConstantInt()->getValue();
795 DwarfExpr.addUnsignedConstant(RawBytes);
796 } else if (Entry.isTargetIndexLocation()) {
797 TargetIndexLocation Loc = Entry.getTargetIndexLocation();
798 // TODO TargetIndexLocation is a target-independent. Currently only the
799 // WebAssembly-specific encoding is supported.
800 assert(Asm->TM.getTargetTriple().isWasm())((void)0);
801 DwarfExpr.addWasmLocation(Loc.Index, static_cast<uint64_t>(Loc.Offset));
802 } else {
803 llvm_unreachable("Unsupported Entry type.")__builtin_unreachable();
804 }
805 return true;
806 };
807
808 DwarfExpr.addExpression(
809 std::move(Cursor),
810 [&](unsigned Idx, DIExpressionCursor &Cursor) -> bool {
811 return AddEntry(DVal->getLocEntries()[Idx], Cursor);
812 });
813
814 // Now attach the location information to the DIE.
815 addBlock(*VariableDie, dwarf::DW_AT_location, DwarfExpr.finalize());
816 if (DwarfExpr.TagOffset)
817 addUInt(*VariableDie, dwarf::DW_AT_LLVM_tag_offset, dwarf::DW_FORM_data1,
818 *DwarfExpr.TagOffset);
819
820 return VariableDie;
821 }
822
823 // .. else use frame index.
824 if (!DV.hasFrameIndexExprs())
825 return VariableDie;
826
827 Optional<unsigned> NVPTXAddressSpace;
828 DIELoc *Loc = new (DIEValueAllocator) DIELoc;
829 DIEDwarfExpression DwarfExpr(*Asm, *this, *Loc);
830 for (auto &Fragment : DV.getFrameIndexExprs()) {
831 Register FrameReg;
832 const DIExpression *Expr = Fragment.Expr;
833 const TargetFrameLowering *TFI = Asm->MF->getSubtarget().getFrameLowering();
834 StackOffset Offset =
835 TFI->getFrameIndexReference(*Asm->MF, Fragment.FI, FrameReg);
836 DwarfExpr.addFragmentOffset(Expr);
837
838 auto *TRI = Asm->MF->getSubtarget().getRegisterInfo();
839 SmallVector<uint64_t, 8> Ops;
840 TRI->getOffsetOpcodes(Offset, Ops);
841
842 // According to
843 // https://docs.nvidia.com/cuda/archive/10.0/ptx-writers-guide-to-interoperability/index.html#cuda-specific-dwarf
844 // cuda-gdb requires DW_AT_address_class for all variables to be able to
845 // correctly interpret address space of the variable address.
846 // Decode DW_OP_constu <DWARF Address Space> DW_OP_swap DW_OP_xderef
847 // sequence for the NVPTX + gdb target.
848 unsigned LocalNVPTXAddressSpace;
849 if (Asm->TM.getTargetTriple().isNVPTX() && DD->tuneForGDB()) {
850 const DIExpression *NewExpr =
851 DIExpression::extractAddressClass(Expr, LocalNVPTXAddressSpace);
852 if (NewExpr != Expr) {
853 Expr = NewExpr;
854 NVPTXAddressSpace = LocalNVPTXAddressSpace;
855 }
856 }
857 if (Expr)
858 Ops.append(Expr->elements_begin(), Expr->elements_end());
859 DIExpressionCursor Cursor(Ops);
860 DwarfExpr.setMemoryLocationKind();
861 if (const MCSymbol *FrameSymbol = Asm->getFunctionFrameSymbol())
862 addOpAddress(*Loc, FrameSymbol);
863 else
864 DwarfExpr.addMachineRegExpression(
865 *Asm->MF->getSubtarget().getRegisterInfo(), Cursor, FrameReg);
866 DwarfExpr.addExpression(std::move(Cursor));
867 }
868 if (Asm->TM.getTargetTriple().isNVPTX() && DD->tuneForGDB()) {
869 // According to
870 // https://docs.nvidia.com/cuda/archive/10.0/ptx-writers-guide-to-interoperability/index.html#cuda-specific-dwarf
871 // cuda-gdb requires DW_AT_address_class for all variables to be able to
872 // correctly interpret address space of the variable address.
873 const unsigned NVPTX_ADDR_local_space = 6;
874 addUInt(*VariableDie, dwarf::DW_AT_address_class, dwarf::DW_FORM_data1,
875 NVPTXAddressSpace ? *NVPTXAddressSpace : NVPTX_ADDR_local_space);
876 }
877 addBlock(*VariableDie, dwarf::DW_AT_location, DwarfExpr.finalize());
878 if (DwarfExpr.TagOffset)
879 addUInt(*VariableDie, dwarf::DW_AT_LLVM_tag_offset, dwarf::DW_FORM_data1,
880 *DwarfExpr.TagOffset);
881
882 return VariableDie;
883}
884
885DIE *DwarfCompileUnit::constructVariableDIE(DbgVariable &DV,
886 const LexicalScope &Scope,
887 DIE *&ObjectPointer) {
888 auto Var = constructVariableDIE(DV, Scope.isAbstractScope());
889 if (DV.isObjectPointer())
890 ObjectPointer = Var;
891 return Var;
892}
893
894/// Return all DIVariables that appear in count: expressions.
895static SmallVector<const DIVariable *, 2> dependencies(DbgVariable *Var) {
896 SmallVector<const DIVariable *, 2> Result;
897 auto *Array = dyn_cast<DICompositeType>(Var->getType());
898 if (!Array || Array->getTag() != dwarf::DW_TAG_array_type)
899 return Result;
900 if (auto *DLVar = Array->getDataLocation())
901 Result.push_back(DLVar);
902 if (auto *AsVar = Array->getAssociated())
903 Result.push_back(AsVar);
904 if (auto *AlVar = Array->getAllocated())
905 Result.push_back(AlVar);
906 for (auto *El : Array->getElements()) {
907 if (auto *Subrange = dyn_cast<DISubrange>(El)) {
908 if (auto Count = Subrange->getCount())
909 if (auto *Dependency = Count.dyn_cast<DIVariable *>())
910 Result.push_back(Dependency);
911 if (auto LB = Subrange->getLowerBound())
912 if (auto *Dependency = LB.dyn_cast<DIVariable *>())
913 Result.push_back(Dependency);
914 if (auto UB = Subrange->getUpperBound())
915 if (auto *Dependency = UB.dyn_cast<DIVariable *>())
916 Result.push_back(Dependency);
917 if (auto ST = Subrange->getStride())
918 if (auto *Dependency = ST.dyn_cast<DIVariable *>())
919 Result.push_back(Dependency);
920 } else if (auto *GenericSubrange = dyn_cast<DIGenericSubrange>(El)) {
921 if (auto Count = GenericSubrange->getCount())
922 if (auto *Dependency = Count.dyn_cast<DIVariable *>())
923 Result.push_back(Dependency);
924 if (auto LB = GenericSubrange->getLowerBound())
925 if (auto *Dependency = LB.dyn_cast<DIVariable *>())
926 Result.push_back(Dependency);
927 if (auto UB = GenericSubrange->getUpperBound())
928 if (auto *Dependency = UB.dyn_cast<DIVariable *>())
929 Result.push_back(Dependency);
930 if (auto ST = GenericSubrange->getStride())
931 if (auto *Dependency = ST.dyn_cast<DIVariable *>())
932 Result.push_back(Dependency);
933 }
934 }
935 return Result;
936}
937
938/// Sort local variables so that variables appearing inside of helper
939/// expressions come first.
940static SmallVector<DbgVariable *, 8>
941sortLocalVars(SmallVectorImpl<DbgVariable *> &Input) {
942 SmallVector<DbgVariable *, 8> Result;
943 SmallVector<PointerIntPair<DbgVariable *, 1>, 8> WorkList;
944 // Map back from a DIVariable to its containing DbgVariable.
945 SmallDenseMap<const DILocalVariable *, DbgVariable *> DbgVar;
946 // Set of DbgVariables in Result.
947 SmallDenseSet<DbgVariable *, 8> Visited;
948 // For cycle detection.
949 SmallDenseSet<DbgVariable *, 8> Visiting;
950
951 // Initialize the worklist and the DIVariable lookup table.
952 for (auto Var : reverse(Input)) {
953 DbgVar.insert({Var->getVariable(), Var});
954 WorkList.push_back({Var, 0});
955 }
956
957 // Perform a stable topological sort by doing a DFS.
958 while (!WorkList.empty()) {
959 auto Item = WorkList.back();
960 DbgVariable *Var = Item.getPointer();
961 bool visitedAllDependencies = Item.getInt();
962 WorkList.pop_back();
963
964 // Dependency is in a different lexical scope or a global.
965 if (!Var)
966 continue;
967
968 // Already handled.
969 if (Visited.count(Var))
970 continue;
971
972 // Add to Result if all dependencies are visited.
973 if (visitedAllDependencies) {
974 Visited.insert(Var);
975 Result.push_back(Var);
976 continue;
977 }
978
979 // Detect cycles.
980 auto Res = Visiting.insert(Var);
981 if (!Res.second) {
982 assert(false && "dependency cycle in local variables")((void)0);
983 return Result;
984 }
985
986 // Push dependencies and this node onto the worklist, so that this node is
987 // visited again after all of its dependencies are handled.
988 WorkList.push_back({Var, 1});
989 for (auto *Dependency : dependencies(Var)) {
990 auto Dep = dyn_cast_or_null<const DILocalVariable>(Dependency);
991 WorkList.push_back({DbgVar[Dep], 0});
992 }
993 }
994 return Result;
995}
996
997DIE *DwarfCompileUnit::createScopeChildrenDIE(LexicalScope *Scope,
998 SmallVectorImpl<DIE *> &Children,
999 bool *HasNonScopeChildren) {
1000 assert(Children.empty())((void)0);
1001 DIE *ObjectPointer = nullptr;
1002
1003 // Emit function arguments (order is significant).
1004 auto Vars = DU->getScopeVariables().lookup(Scope);
1005 for (auto &DV : Vars.Args)
1006 Children.push_back(constructVariableDIE(*DV.second, *Scope, ObjectPointer));
1007
1008 // Emit local variables.
1009 auto Locals = sortLocalVars(Vars.Locals);
1010 for (DbgVariable *DV : Locals)
1011 Children.push_back(constructVariableDIE(*DV, *Scope, ObjectPointer));
1012
1013 // Skip imported directives in gmlt-like data.
1014 if (!includeMinimalInlineScopes()) {
1015 // There is no need to emit empty lexical block DIE.
1016 for (const auto *IE : ImportedEntities[Scope->getScopeNode()])
1017 Children.push_back(
1018 constructImportedEntityDIE(cast<DIImportedEntity>(IE)));
1019 }
1020
1021 if (HasNonScopeChildren)
1022 *HasNonScopeChildren = !Children.empty();
1023
1024 for (DbgLabel *DL : DU->getScopeLabels().lookup(Scope))
1025 Children.push_back(constructLabelDIE(*DL, *Scope));
1026
1027 for (LexicalScope *LS : Scope->getChildren())
1028 constructScopeDIE(LS, Children);
1029
1030 return ObjectPointer;
1031}
1032
1033DIE &DwarfCompileUnit::constructSubprogramScopeDIE(const DISubprogram *Sub,
1034 LexicalScope *Scope) {
1035 DIE &ScopeDIE = updateSubprogramScopeDIE(Sub);
1036
1037 if (Scope) {
1038 assert(!Scope->getInlinedAt())((void)0);
1039 assert(!Scope->isAbstractScope())((void)0);
1040 // Collect lexical scope children first.
1041 // ObjectPointer might be a local (non-argument) local variable if it's a
1042 // block's synthetic this pointer.
1043 if (DIE *ObjectPointer = createAndAddScopeChildren(Scope, ScopeDIE))
1044 addDIEEntry(ScopeDIE, dwarf::DW_AT_object_pointer, *ObjectPointer);
1045 }
1046
1047 // If this is a variadic function, add an unspecified parameter.
1048 DITypeRefArray FnArgs = Sub->getType()->getTypeArray();
1049
1050 // If we have a single element of null, it is a function that returns void.
1051 // If we have more than one elements and the last one is null, it is a
1052 // variadic function.
1053 if (FnArgs.size() > 1 && !FnArgs[FnArgs.size() - 1] &&
1054 !includeMinimalInlineScopes())
1055 ScopeDIE.addChild(
1056 DIE::get(DIEValueAllocator, dwarf::DW_TAG_unspecified_parameters));
1057
1058 return ScopeDIE;
1059}
1060
1061DIE *DwarfCompileUnit::createAndAddScopeChildren(LexicalScope *Scope,
1062 DIE &ScopeDIE) {
1063 // We create children when the scope DIE is not null.
1064 SmallVector<DIE *, 8> Children;
1065 DIE *ObjectPointer = createScopeChildrenDIE(Scope, Children);
1066
1067 // Add children
1068 for (auto &I : Children)
1069 ScopeDIE.addChild(std::move(I));
1070
1071 return ObjectPointer;
1072}
1073
1074void DwarfCompileUnit::constructAbstractSubprogramScopeDIE(
1075 LexicalScope *Scope) {
1076 DIE *&AbsDef = getAbstractSPDies()[Scope->getScopeNode()];
1077 if (AbsDef)
1078 return;
1079
1080 auto *SP = cast<DISubprogram>(Scope->getScopeNode());
1081
1082 DIE *ContextDIE;
1083 DwarfCompileUnit *ContextCU = this;
1084
1085 if (includeMinimalInlineScopes())
1086 ContextDIE = &getUnitDie();
1087 // Some of this is duplicated from DwarfUnit::getOrCreateSubprogramDIE, with
1088 // the important distinction that the debug node is not associated with the
1089 // DIE (since the debug node will be associated with the concrete DIE, if
1090 // any). It could be refactored to some common utility function.
1091 else if (auto *SPDecl = SP->getDeclaration()) {
1092 ContextDIE = &getUnitDie();
1093 getOrCreateSubprogramDIE(SPDecl);
1094 } else {
1095 ContextDIE = getOrCreateContextDIE(SP->getScope());
1096 // The scope may be shared with a subprogram that has already been
1097 // constructed in another CU, in which case we need to construct this
1098 // subprogram in the same CU.
1099 ContextCU = DD->lookupCU(ContextDIE->getUnitDie());
1100 }
1101
1102 // Passing null as the associated node because the abstract definition
1103 // shouldn't be found by lookup.
1104 AbsDef = &ContextCU->createAndAddDIE(dwarf::DW_TAG_subprogram, *ContextDIE, nullptr);
1105 ContextCU->applySubprogramAttributesToDefinition(SP, *AbsDef);
1106
1107 if (!ContextCU->includeMinimalInlineScopes())
1108 ContextCU->addUInt(*AbsDef, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
1109 if (DIE *ObjectPointer = ContextCU->createAndAddScopeChildren(Scope, *AbsDef))
1110 ContextCU->addDIEEntry(*AbsDef, dwarf::DW_AT_object_pointer, *ObjectPointer);
1111}
1112
1113bool DwarfCompileUnit::useGNUAnalogForDwarf5Feature() const {
1114 return DD->getDwarfVersion() == 4 && !DD->tuneForLLDB();
1115}
1116
1117dwarf::Tag DwarfCompileUnit::getDwarf5OrGNUTag(dwarf::Tag Tag) const {
1118 if (!useGNUAnalogForDwarf5Feature())
1119 return Tag;
1120 switch (Tag) {
1121 case dwarf::DW_TAG_call_site:
1122 return dwarf::DW_TAG_GNU_call_site;
1123 case dwarf::DW_TAG_call_site_parameter:
1124 return dwarf::DW_TAG_GNU_call_site_parameter;
1125 default:
1126 llvm_unreachable("DWARF5 tag with no GNU analog")__builtin_unreachable();
1127 }
1128}
1129
1130dwarf::Attribute
1131DwarfCompileUnit::getDwarf5OrGNUAttr(dwarf::Attribute Attr) const {
1132 if (!useGNUAnalogForDwarf5Feature())
1133 return Attr;
1134 switch (Attr) {
1135 case dwarf::DW_AT_call_all_calls:
1136 return dwarf::DW_AT_GNU_all_call_sites;
1137 case dwarf::DW_AT_call_target:
1138 return dwarf::DW_AT_GNU_call_site_target;
1139 case dwarf::DW_AT_call_origin:
1140 return dwarf::DW_AT_abstract_origin;
1141 case dwarf::DW_AT_call_return_pc:
1142 return dwarf::DW_AT_low_pc;
1143 case dwarf::DW_AT_call_value:
1144 return dwarf::DW_AT_GNU_call_site_value;
1145 case dwarf::DW_AT_call_tail_call:
1146 return dwarf::DW_AT_GNU_tail_call;
1147 default:
1148 llvm_unreachable("DWARF5 attribute with no GNU analog")__builtin_unreachable();
1149 }
1150}
1151
1152dwarf::LocationAtom
1153DwarfCompileUnit::getDwarf5OrGNULocationAtom(dwarf::LocationAtom Loc) const {
1154 if (!useGNUAnalogForDwarf5Feature())
1155 return Loc;
1156 switch (Loc) {
1157 case dwarf::DW_OP_entry_value:
1158 return dwarf::DW_OP_GNU_entry_value;
1159 default:
1160 llvm_unreachable("DWARF5 location atom with no GNU analog")__builtin_unreachable();
1161 }
1162}
1163
1164DIE &DwarfCompileUnit::constructCallSiteEntryDIE(DIE &ScopeDIE,
1165 const DISubprogram *CalleeSP,
1166 bool IsTail,
1167 const MCSymbol *PCAddr,
1168 const MCSymbol *CallAddr,
1169 unsigned CallReg) {
1170 // Insert a call site entry DIE within ScopeDIE.
1171 DIE &CallSiteDIE = createAndAddDIE(getDwarf5OrGNUTag(dwarf::DW_TAG_call_site),
1172 ScopeDIE, nullptr);
1173
1174 if (CallReg) {
1175 // Indirect call.
1176 addAddress(CallSiteDIE, getDwarf5OrGNUAttr(dwarf::DW_AT_call_target),
1177 MachineLocation(CallReg));
1178 } else {
1179 DIE *CalleeDIE = getOrCreateSubprogramDIE(CalleeSP);
1180 assert(CalleeDIE && "Could not create DIE for call site entry origin")((void)0);
1181 addDIEEntry(CallSiteDIE, getDwarf5OrGNUAttr(dwarf::DW_AT_call_origin),
1182 *CalleeDIE);
1183 }
1184
1185 if (IsTail) {
1186 // Attach DW_AT_call_tail_call to tail calls for standards compliance.
1187 addFlag(CallSiteDIE, getDwarf5OrGNUAttr(dwarf::DW_AT_call_tail_call));
1188
1189 // Attach the address of the branch instruction to allow the debugger to
1190 // show where the tail call occurred. This attribute has no GNU analog.
1191 //
1192 // GDB works backwards from non-standard usage of DW_AT_low_pc (in DWARF4
1193 // mode -- equivalently, in DWARF5 mode, DW_AT_call_return_pc) at tail-call
1194 // site entries to figure out the PC of tail-calling branch instructions.
1195 // This means it doesn't need the compiler to emit DW_AT_call_pc, so we
1196 // don't emit it here.
1197 //
1198 // There's no need to tie non-GDB debuggers to this non-standardness, as it
1199 // adds unnecessary complexity to the debugger. For non-GDB debuggers, emit
1200 // the standard DW_AT_call_pc info.
1201 if (!useGNUAnalogForDwarf5Feature())
1202 addLabelAddress(CallSiteDIE, dwarf::DW_AT_call_pc, CallAddr);
1203 }
1204
1205 // Attach the return PC to allow the debugger to disambiguate call paths
1206 // from one function to another.
1207 //
1208 // The return PC is only really needed when the call /isn't/ a tail call, but
1209 // GDB expects it in DWARF4 mode, even for tail calls (see the comment above
1210 // the DW_AT_call_pc emission logic for an explanation).
1211 if (!IsTail || useGNUAnalogForDwarf5Feature()) {
1212 assert(PCAddr && "Missing return PC information for a call")((void)0);
1213 addLabelAddress(CallSiteDIE,
1214 getDwarf5OrGNUAttr(dwarf::DW_AT_call_return_pc), PCAddr);
1215 }
1216
1217 return CallSiteDIE;
1218}
1219
1220void DwarfCompileUnit::constructCallSiteParmEntryDIEs(
1221 DIE &CallSiteDIE, SmallVector<DbgCallSiteParam, 4> &Params) {
1222 for (const auto &Param : Params) {
1223 unsigned Register = Param.getRegister();
1224 auto CallSiteDieParam =
1225 DIE::get(DIEValueAllocator,
1226 getDwarf5OrGNUTag(dwarf::DW_TAG_call_site_parameter));
1227 insertDIE(CallSiteDieParam);
1228 addAddress(*CallSiteDieParam, dwarf::DW_AT_location,
1229 MachineLocation(Register));
1230
1231 DIELoc *Loc = new (DIEValueAllocator) DIELoc;
1232 DIEDwarfExpression DwarfExpr(*Asm, *this, *Loc);
1233 DwarfExpr.setCallSiteParamValueFlag();
1234
1235 DwarfDebug::emitDebugLocValue(*Asm, nullptr, Param.getValue(), DwarfExpr);
1236
1237 addBlock(*CallSiteDieParam, getDwarf5OrGNUAttr(dwarf::DW_AT_call_value),
1238 DwarfExpr.finalize());
1239
1240 CallSiteDIE.addChild(CallSiteDieParam);
1241 }
1242}
1243
1244DIE *DwarfCompileUnit::constructImportedEntityDIE(
1245 const DIImportedEntity *Module) {
1246 DIE *IMDie = DIE::get(DIEValueAllocator, (dwarf::Tag)Module->getTag());
1247 insertDIE(Module, IMDie);
1248 DIE *EntityDie;
1249 auto *Entity = Module->getEntity();
1250 if (auto *NS = dyn_cast<DINamespace>(Entity))
1251 EntityDie = getOrCreateNameSpace(NS);
1252 else if (auto *M = dyn_cast<DIModule>(Entity))
1253 EntityDie = getOrCreateModule(M);
1254 else if (auto *SP = dyn_cast<DISubprogram>(Entity))
1255 EntityDie = getOrCreateSubprogramDIE(SP);
1256 else if (auto *T = dyn_cast<DIType>(Entity))
1257 EntityDie = getOrCreateTypeDIE(T);
1258 else if (auto *GV = dyn_cast<DIGlobalVariable>(Entity))
1259 EntityDie = getOrCreateGlobalVariableDIE(GV, {});
1260 else
1261 EntityDie = getDIE(Entity);
1262 assert(EntityDie)((void)0);
1263 addSourceLine(*IMDie, Module->getLine(), Module->getFile());
1264 addDIEEntry(*IMDie, dwarf::DW_AT_import, *EntityDie);
1265 StringRef Name = Module->getName();
1266 if (!Name.empty())
1267 addString(*IMDie, dwarf::DW_AT_name, Name);
1268
1269 return IMDie;
1270}
1271
1272void DwarfCompileUnit::finishSubprogramDefinition(const DISubprogram *SP) {
1273 DIE *D = getDIE(SP);
1274 if (DIE *AbsSPDIE = getAbstractSPDies().lookup(SP)) {
1275 if (D)
1276 // If this subprogram has an abstract definition, reference that
1277 addDIEEntry(*D, dwarf::DW_AT_abstract_origin, *AbsSPDIE);
1278 } else {
1279 assert(D || includeMinimalInlineScopes())((void)0);
1280 if (D)
1281 // And attach the attributes
1282 applySubprogramAttributesToDefinition(SP, *D);
1283 }
1284}
1285
1286void DwarfCompileUnit::finishEntityDefinition(const DbgEntity *Entity) {
1287 DbgEntity *AbsEntity = getExistingAbstractEntity(Entity->getEntity());
1288
1289 auto *Die = Entity->getDIE();
1290 /// Label may be used to generate DW_AT_low_pc, so put it outside
1291 /// if/else block.
1292 const DbgLabel *Label = nullptr;
1293 if (AbsEntity && AbsEntity->getDIE()) {
1294 addDIEEntry(*Die, dwarf::DW_AT_abstract_origin, *AbsEntity->getDIE());
1295 Label = dyn_cast<const DbgLabel>(Entity);
1296 } else {
1297 if (const DbgVariable *Var = dyn_cast<const DbgVariable>(Entity))
1298 applyVariableAttributes(*Var, *Die);
1299 else if ((Label = dyn_cast<const DbgLabel>(Entity)))
1300 applyLabelAttributes(*Label, *Die);
1301 else
1302 llvm_unreachable("DbgEntity must be DbgVariable or DbgLabel.")__builtin_unreachable();
1303 }
1304
1305 if (Label)
1306 if (const auto *Sym = Label->getSymbol())
1307 addLabelAddress(*Die, dwarf::DW_AT_low_pc, Sym);
1308}
1309
1310DbgEntity *DwarfCompileUnit::getExistingAbstractEntity(const DINode *Node) {
1311 auto &AbstractEntities = getAbstractEntities();
1312 auto I = AbstractEntities.find(Node);
1313 if (I != AbstractEntities.end())
1314 return I->second.get();
1315 return nullptr;
1316}
1317
1318void DwarfCompileUnit::createAbstractEntity(const DINode *Node,
1319 LexicalScope *Scope) {
1320 assert(Scope && Scope->isAbstractScope())((void)0);
1321 auto &Entity = getAbstractEntities()[Node];
1322 if (isa<const DILocalVariable>(Node)) {
1323 Entity = std::make_unique<DbgVariable>(
1324 cast<const DILocalVariable>(Node), nullptr /* IA */);;
1325 DU->addScopeVariable(Scope, cast<DbgVariable>(Entity.get()));
1326 } else if (isa<const DILabel>(Node)) {
1327 Entity = std::make_unique<DbgLabel>(
1328 cast<const DILabel>(Node), nullptr /* IA */);
1329 DU->addScopeLabel(Scope, cast<DbgLabel>(Entity.get()));
1330 }
1331}
1332
1333void DwarfCompileUnit::emitHeader(bool UseOffsets) {
1334 // Don't bother labeling the .dwo unit, as its offset isn't used.
1335 if (!Skeleton && !DD->useSectionsAsReferences()) {
1336 LabelBegin = Asm->createTempSymbol("cu_begin");
1337 Asm->OutStreamer->emitLabel(LabelBegin);
1338 }
1339
1340 dwarf::UnitType UT = Skeleton ? dwarf::DW_UT_split_compile
1341 : DD->useSplitDwarf() ? dwarf::DW_UT_skeleton
1342 : dwarf::DW_UT_compile;
1343 DwarfUnit::emitCommonHeader(UseOffsets, UT);
1344 if (DD->getDwarfVersion() >= 5 && UT != dwarf::DW_UT_compile)
1345 Asm->emitInt64(getDWOId());
1346}
1347
1348bool DwarfCompileUnit::hasDwarfPubSections() const {
1349 switch (CUNode->getNameTableKind()) {
1350 case DICompileUnit::DebugNameTableKind::None:
1351 return false;
1352 // Opting in to GNU Pubnames/types overrides the default to ensure these are
1353 // generated for things like Gold's gdb_index generation.
1354 case DICompileUnit::DebugNameTableKind::GNU:
1355 return true;
1356 case DICompileUnit::DebugNameTableKind::Default:
1357 return DD->tuneForGDB() && !includeMinimalInlineScopes() &&
1358 !CUNode->isDebugDirectivesOnly() &&
1359 DD->getAccelTableKind() != AccelTableKind::Apple &&
1360 DD->getDwarfVersion() < 5;
1361 }
1362 llvm_unreachable("Unhandled DICompileUnit::DebugNameTableKind enum")__builtin_unreachable();
1363}
1364
1365/// addGlobalName - Add a new global name to the compile unit.
1366void DwarfCompileUnit::addGlobalName(StringRef Name, const DIE &Die,
1367 const DIScope *Context) {
1368 if (!hasDwarfPubSections())
1369 return;
1370 std::string FullName = getParentContextString(Context) + Name.str();
1371 GlobalNames[FullName] = &Die;
1372}
1373
1374void DwarfCompileUnit::addGlobalNameForTypeUnit(StringRef Name,
1375 const DIScope *Context) {
1376 if (!hasDwarfPubSections())
1377 return;
1378 std::string FullName = getParentContextString(Context) + Name.str();
1379 // Insert, allowing the entry to remain as-is if it's already present
1380 // This way the CU-level type DIE is preferred over the "can't describe this
1381 // type as a unit offset because it's not really in the CU at all, it's only
1382 // in a type unit"
1383 GlobalNames.insert(std::make_pair(std::move(FullName), &getUnitDie()));
1384}
1385
1386/// Add a new global type to the unit.
1387void DwarfCompileUnit::addGlobalType(const DIType *Ty, const DIE &Die,
1388 const DIScope *Context) {
1389 if (!hasDwarfPubSections())
1390 return;
1391 std::string FullName = getParentContextString(Context) + Ty->getName().str();
1392 GlobalTypes[FullName] = &Die;
1393}
1394
1395void DwarfCompileUnit::addGlobalTypeUnitType(const DIType *Ty,
1396 const DIScope *Context) {
1397 if (!hasDwarfPubSections())
1398 return;
1399 std::string FullName = getParentContextString(Context) + Ty->getName().str();
1400 // Insert, allowing the entry to remain as-is if it's already present
1401 // This way the CU-level type DIE is preferred over the "can't describe this
1402 // type as a unit offset because it's not really in the CU at all, it's only
1403 // in a type unit"
1404 GlobalTypes.insert(std::make_pair(std::move(FullName), &getUnitDie()));
1405}
1406
1407void DwarfCompileUnit::addVariableAddress(const DbgVariable &DV, DIE &Die,
1408 MachineLocation Location) {
1409 if (DV.hasComplexAddress())
1410 addComplexAddress(DV, Die, dwarf::DW_AT_location, Location);
1411 else
1412 addAddress(Die, dwarf::DW_AT_location, Location);
1413}
1414
1415/// Add an address attribute to a die based on the location provided.
1416void DwarfCompileUnit::addAddress(DIE &Die, dwarf::Attribute Attribute,
1417 const MachineLocation &Location) {
1418 DIELoc *Loc = new (DIEValueAllocator) DIELoc;
1419 DIEDwarfExpression DwarfExpr(*Asm, *this, *Loc);
1420 if (Location.isIndirect())
1421 DwarfExpr.setMemoryLocationKind();
1422
1423 DIExpressionCursor Cursor({});
1424 const TargetRegisterInfo &TRI = *Asm->MF->getSubtarget().getRegisterInfo();
1425 if (!DwarfExpr.addMachineRegExpression(TRI, Cursor, Location.getReg()))
1426 return;
1427 DwarfExpr.addExpression(std::move(Cursor));
1428
1429 // Now attach the location information to the DIE.
1430 addBlock(Die, Attribute, DwarfExpr.finalize());
1431
1432 if (DwarfExpr.TagOffset)
1433 addUInt(Die, dwarf::DW_AT_LLVM_tag_offset, dwarf::DW_FORM_data1,
1434 *DwarfExpr.TagOffset);
1435}
1436
1437/// Start with the address based on the location provided, and generate the
1438/// DWARF information necessary to find the actual variable given the extra
1439/// address information encoded in the DbgVariable, starting from the starting
1440/// location. Add the DWARF information to the die.
1441void DwarfCompileUnit::addComplexAddress(const DbgVariable &DV, DIE &Die,
1442 dwarf::Attribute Attribute,
1443 const MachineLocation &Location) {
1444 DIELoc *Loc = new (DIEValueAllocator) DIELoc;
1445 DIEDwarfExpression DwarfExpr(*Asm, *this, *Loc);
1446 const DIExpression *DIExpr = DV.getSingleExpression();
1447 DwarfExpr.addFragmentOffset(DIExpr);
1448 DwarfExpr.setLocation(Location, DIExpr);
1449
1450 DIExpressionCursor Cursor(DIExpr);
1451
1452 if (DIExpr->isEntryValue())
1453 DwarfExpr.beginEntryValueExpression(Cursor);
1454
1455 const TargetRegisterInfo &TRI = *Asm->MF->getSubtarget().getRegisterInfo();
1456 if (!DwarfExpr.addMachineRegExpression(TRI, Cursor, Location.getReg()))
1457 return;
1458 DwarfExpr.addExpression(std::move(Cursor));
1459
1460 // Now attach the location information to the DIE.
1461 addBlock(Die, Attribute, DwarfExpr.finalize());
1462
1463 if (DwarfExpr.TagOffset)
1464 addUInt(Die, dwarf::DW_AT_LLVM_tag_offset, dwarf::DW_FORM_data1,
1465 *DwarfExpr.TagOffset);
1466}
1467
1468/// Add a Dwarf loclistptr attribute data and value.
1469void DwarfCompileUnit::addLocationList(DIE &Die, dwarf::Attribute Attribute,
1470 unsigned Index) {
1471 dwarf::Form Form = (DD->getDwarfVersion() >= 5)
1472 ? dwarf::DW_FORM_loclistx
1473 : DD->getDwarfSectionOffsetForm();
1474 addAttribute(Die, Attribute, Form, DIELocList(Index));
1475}
1476
1477void DwarfCompileUnit::applyVariableAttributes(const DbgVariable &Var,
1478 DIE &VariableDie) {
1479 StringRef Name = Var.getName();
1480 if (!Name.empty())
1481 addString(VariableDie, dwarf::DW_AT_name, Name);
1482 const auto *DIVar = Var.getVariable();
1483 if (DIVar)
1484 if (uint32_t AlignInBytes = DIVar->getAlignInBytes())
1485 addUInt(VariableDie, dwarf::DW_AT_alignment, dwarf::DW_FORM_udata,
1486 AlignInBytes);
1487
1488 addSourceLine(VariableDie, DIVar);
1489 addType(VariableDie, Var.getType());
1490 if (Var.isArtificial())
1491 addFlag(VariableDie, dwarf::DW_AT_artificial);
1492}
1493
1494void DwarfCompileUnit::applyLabelAttributes(const DbgLabel &Label,
1495 DIE &LabelDie) {
1496 StringRef Name = Label.getName();
1497 if (!Name.empty())
1498 addString(LabelDie, dwarf::DW_AT_name, Name);
1499 const auto *DILabel = Label.getLabel();
1500 addSourceLine(LabelDie, DILabel);
1501}
1502
1503/// Add a Dwarf expression attribute data and value.
1504void DwarfCompileUnit::addExpr(DIELoc &Die, dwarf::Form Form,
1505 const MCExpr *Expr) {
1506 addAttribute(Die, (dwarf::Attribute)0, Form, DIEExpr(Expr));
1507}
1508
1509void DwarfCompileUnit::applySubprogramAttributesToDefinition(
1510 const DISubprogram *SP, DIE &SPDie) {
1511 auto *SPDecl = SP->getDeclaration();
1512 auto *Context = SPDecl ? SPDecl->getScope() : SP->getScope();
1513 applySubprogramAttributes(SP, SPDie, includeMinimalInlineScopes());
1514 addGlobalName(SP->getName(), SPDie, Context);
1515}
1516
1517bool DwarfCompileUnit::isDwoUnit() const {
1518 return DD->useSplitDwarf() && Skeleton;
1519}
1520
1521void DwarfCompileUnit::finishNonUnitTypeDIE(DIE& D, const DICompositeType *CTy) {
1522 constructTypeDIE(D, CTy);
1523}
1524
1525bool DwarfCompileUnit::includeMinimalInlineScopes() const {
1526 return getCUNode()->getEmissionKind() == DICompileUnit::LineTablesOnly ||
1527 (DD->useSplitDwarf() && !Skeleton);
1528}
1529
1530void DwarfCompileUnit::addAddrTableBase() {
1531 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
1532 MCSymbol *Label = DD->getAddressPool().getLabel();
1533 addSectionLabel(getUnitDie(),
1534 DD->getDwarfVersion() >= 5 ? dwarf::DW_AT_addr_base
1535 : dwarf::DW_AT_GNU_addr_base,
1536 Label, TLOF.getDwarfAddrSection()->getBeginSymbol());
1537}
1538
1539void DwarfCompileUnit::addBaseTypeRef(DIEValueList &Die, int64_t Idx) {
1540 addAttribute(Die, (dwarf::Attribute)0, dwarf::DW_FORM_udata,
1541 new (DIEValueAllocator) DIEBaseTypeRef(this, Idx));
1542}
1543
1544void DwarfCompileUnit::createBaseTypeDIEs() {
1545 // Insert the base_type DIEs directly after the CU so that their offsets will
1546 // fit in the fixed size ULEB128 used inside the location expressions.
1547 // Maintain order by iterating backwards and inserting to the front of CU
1548 // child list.
1549 for (auto &Btr : reverse(ExprRefedBaseTypes)) {
1550 DIE &Die = getUnitDie().addChildFront(
1551 DIE::get(DIEValueAllocator, dwarf::DW_TAG_base_type));
1
Calling 'DIE::get'
→
1552 SmallString<32> Str;
1553 addString(Die, dwarf::DW_AT_name,
1554 Twine(dwarf::AttributeEncodingString(Btr.Encoding) +
1555 "_" + Twine(Btr.BitSize)).toStringRef(Str));
1556 addUInt(Die, dwarf::DW_AT_encoding, dwarf::DW_FORM_data1, Btr.Encoding);
1557 addUInt(Die, dwarf::DW_AT_byte_size, None, Btr.BitSize / 8);
1558
1559 Btr.Die = &Die;
1560 }
1561}
←

/usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/CodeGen/DIE.h

→
1//===- lib/CodeGen/DIE.h - DWARF Info Entries -------------------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// Data structures for DWARF info entries.
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_CODEGEN_DIE_H
14#define LLVM_CODEGEN_DIE_H
15
16#include "llvm/ADT/FoldingSet.h"
17#include "llvm/ADT/PointerIntPair.h"
18#include "llvm/ADT/PointerUnion.h"
19#include "llvm/ADT/SmallVector.h"
20#include "llvm/ADT/StringRef.h"
21#include "llvm/ADT/iterator.h"
22#include "llvm/ADT/iterator_range.h"
23#include "llvm/BinaryFormat/Dwarf.h"
24#include "llvm/CodeGen/DwarfStringPoolEntry.h"
25#include "llvm/Support/AlignOf.h"
26#include "llvm/Support/Allocator.h"
27#include <cassert>
28#include <cstddef>
29#include <cstdint>
30#include <iterator>
31#include <new>
32#include <type_traits>
33#include <utility>
34#include <vector>
35
36namespace llvm {
37
38class AsmPrinter;
39class DIE;
40class DIEUnit;
41class DwarfCompileUnit;
42class MCExpr;
43class MCSection;
44class MCSymbol;
45class raw_ostream;
46
47//===--------------------------------------------------------------------===//
48/// Dwarf abbreviation data, describes one attribute of a Dwarf abbreviation.
49class DIEAbbrevData {
50 /// Dwarf attribute code.
51 dwarf::Attribute Attribute;
52
53 /// Dwarf form code.
54 dwarf::Form Form;
55
56 /// Dwarf attribute value for DW_FORM_implicit_const
57 int64_t Value = 0;
58
59public:
60 DIEAbbrevData(dwarf::Attribute A, dwarf::Form F)
61 : Attribute(A), Form(F) {}
62 DIEAbbrevData(dwarf::Attribute A, int64_t V)
63 : Attribute(A), Form(dwarf::DW_FORM_implicit_const), Value(V) {}
64
65 /// Accessors.
66 /// @{
67 dwarf::Attribute getAttribute() const { return Attribute; }
68 dwarf::Form getForm() const { return Form; }
69 int64_t getValue() const { return Value; }
70 /// @}
71
72 /// Used to gather unique data for the abbreviation folding set.
73 void Profile(FoldingSetNodeID &ID) const;
74};
75
76//===--------------------------------------------------------------------===//
77/// Dwarf abbreviation, describes the organization of a debug information
78/// object.
79class DIEAbbrev : public FoldingSetNode {
80 /// Unique number for node.
81 unsigned Number = 0;
82
83 /// Dwarf tag code.
84 dwarf::Tag Tag;
85
86 /// Whether or not this node has children.
87 ///
88 /// This cheats a bit in all of the uses since the values in the standard
89 /// are 0 and 1 for no children and children respectively.
90 bool Children;
91
92 /// Raw data bytes for abbreviation.
93 SmallVector<DIEAbbrevData, 12> Data;
94
95public:
96 DIEAbbrev(dwarf::Tag T, bool C) : Tag(T), Children(C) {}
97
98 /// Accessors.
99 /// @{
100 dwarf::Tag getTag() const { return Tag; }
101 unsigned getNumber() const { return Number; }
102 bool hasChildren() const { return Children; }
103 const SmallVectorImpl<DIEAbbrevData> &getData() const { return Data; }
104 void setChildrenFlag(bool hasChild) { Children = hasChild; }
105 void setNumber(unsigned N) { Number = N; }
106 /// @}
107
108 /// Adds another set of attribute information to the abbreviation.
109 void AddAttribute(dwarf::Attribute Attribute, dwarf::Form Form) {
110 Data.push_back(DIEAbbrevData(Attribute, Form));
111 }
112
113 /// Adds attribute with DW_FORM_implicit_const value
114 void AddImplicitConstAttribute(dwarf::Attribute Attribute, int64_t Value) {
115 Data.push_back(DIEAbbrevData(Attribute, Value));
116 }
117
118 /// Used to gather unique data for the abbreviation folding set.
119 void Profile(FoldingSetNodeID &ID) const;
120
121 /// Print the abbreviation using the specified asm printer.
122 void Emit(const AsmPrinter *AP) const;
123
124 void print(raw_ostream &O) const;
125 void dump() const;
126};
127
128//===--------------------------------------------------------------------===//
129/// Helps unique DIEAbbrev objects and assigns abbreviation numbers.
130///
131/// This class will unique the DIE abbreviations for a llvm::DIE object and
132/// assign a unique abbreviation number to each unique DIEAbbrev object it
133/// finds. The resulting collection of DIEAbbrev objects can then be emitted
134/// into the .debug_abbrev section.
135class DIEAbbrevSet {
136 /// The bump allocator to use when creating DIEAbbrev objects in the uniqued
137 /// storage container.
138 BumpPtrAllocator &Alloc;
139 /// FoldingSet that uniques the abbreviations.
140 FoldingSet<DIEAbbrev> AbbreviationsSet;
141 /// A list of all the unique abbreviations in use.
142 std::vector<DIEAbbrev *> Abbreviations;
143
144public:
145 DIEAbbrevSet(BumpPtrAllocator &A) : Alloc(A) {}
146 ~DIEAbbrevSet();
147
148 /// Generate the abbreviation declaration for a DIE and return a pointer to
149 /// the generated abbreviation.
150 ///
151 /// \param Die the debug info entry to generate the abbreviation for.
152 /// \returns A reference to the uniqued abbreviation declaration that is
153 /// owned by this class.
154 DIEAbbrev &uniqueAbbreviation(DIE &Die);
155
156 /// Print all abbreviations using the specified asm printer.
157 void Emit(const AsmPrinter *AP, MCSection *Section) const;
158};
159
160//===--------------------------------------------------------------------===//
161/// An integer value DIE.
162///
163class DIEInteger {
164 uint64_t Integer;
165
166public:
167 explicit DIEInteger(uint64_t I) : Integer(I) {}
168
169 /// Choose the best form for integer.
170 static dwarf::Form BestForm(bool IsSigned, uint64_t Int) {
171 if (IsSigned) {
172 const int64_t SignedInt = Int;
173 if ((char)Int == SignedInt)
174 return dwarf::DW_FORM_data1;
175 if ((short)Int == SignedInt)
176 return dwarf::DW_FORM_data2;
177 if ((int)Int == SignedInt)
178 return dwarf::DW_FORM_data4;
179 } else {
180 if ((unsigned char)Int == Int)
181 return dwarf::DW_FORM_data1;
182 if ((unsigned short)Int == Int)
183 return dwarf::DW_FORM_data2;
184 if ((unsigned int)Int == Int)
185 return dwarf::DW_FORM_data4;
186 }
187 return dwarf::DW_FORM_data8;
188 }
189
190 uint64_t getValue() const { return Integer; }
191 void setValue(uint64_t Val) { Integer = Val; }
192
193 void emitValue(const AsmPrinter *Asm, dwarf::Form Form) const;
194 unsigned SizeOf(const AsmPrinter *AP, dwarf::Form Form) const;
195
196 void print(raw_ostream &O) const;
197};
198
199//===--------------------------------------------------------------------===//
200/// An expression DIE.
201class DIEExpr {
202 const MCExpr *Expr;
203
204public:
205 explicit DIEExpr(const MCExpr *E) : Expr(E) {}
206
207 /// Get MCExpr.
208 const MCExpr *getValue() const { return Expr; }
209
210 void emitValue(const AsmPrinter *AP, dwarf::Form Form) const;
211 unsigned SizeOf(const AsmPrinter *AP, dwarf::Form Form) const;
212
213 void print(raw_ostream &O) const;
214};
215
216//===--------------------------------------------------------------------===//
217/// A label DIE.
218class DIELabel {
219 const MCSymbol *Label;
220
221public:
222 explicit DIELabel(const MCSymbol *L) : Label(L) {}
223
224 /// Get MCSymbol.
225 const MCSymbol *getValue() const { return Label; }
226
227 void emitValue(const AsmPrinter *AP, dwarf::Form Form) const;
228 unsigned SizeOf(const AsmPrinter *AP, dwarf::Form Form) const;
229
230 void print(raw_ostream &O) const;
231};
232
233//===--------------------------------------------------------------------===//
234/// A BaseTypeRef DIE.
235class DIEBaseTypeRef {
236 const DwarfCompileUnit *CU;
237 const uint64_t Index;
238 static constexpr unsigned ULEB128PadSize = 4;
239
240public:
241 explicit DIEBaseTypeRef(const DwarfCompileUnit *TheCU, uint64_t Idx)
242 : CU(TheCU), Index(Idx) {}
243
244 /// EmitValue - Emit base type reference.
245 void emitValue(const AsmPrinter *AP, dwarf::Form Form) const;
246 /// SizeOf - Determine size of the base type reference in bytes.
247 unsigned SizeOf(const AsmPrinter *AP, dwarf::Form Form) const;
248
249 void print(raw_ostream &O) const;
250 uint64_t getIndex() const { return Index; }
251};
252
253//===--------------------------------------------------------------------===//
254/// A simple label difference DIE.
255///
256class DIEDelta {
257 const MCSymbol *LabelHi;
258 const MCSymbol *LabelLo;
259
260public:
261 DIEDelta(const MCSymbol *Hi, const MCSymbol *Lo) : LabelHi(Hi), LabelLo(Lo) {}
262
263 void emitValue(const AsmPrinter *AP, dwarf::Form Form) const;
264 unsigned SizeOf(const AsmPrinter *AP, dwarf::Form Form) const;
265
266 void print(raw_ostream &O) const;
267};
268
269//===--------------------------------------------------------------------===//
270/// A container for string pool string values.
271///
272/// This class is used with the DW_FORM_strp and DW_FORM_GNU_str_index forms.
273class DIEString {
274 DwarfStringPoolEntryRef S;
275
276public:
277 DIEString(DwarfStringPoolEntryRef S) : S(S) {}
278
279 /// Grab the string out of the object.
280 StringRef getString() const { return S.getString(); }
281
282 void emitValue(const AsmPrinter *AP, dwarf::Form Form) const;
283 unsigned SizeOf(const AsmPrinter *AP, dwarf::Form Form) const;
284
285 void print(raw_ostream &O) const;
286};
287
288//===--------------------------------------------------------------------===//
289/// A container for inline string values.
290///
291/// This class is used with the DW_FORM_string form.
292class DIEInlineString {
293 StringRef S;
294
295public:
296 template <typename Allocator>
297 explicit DIEInlineString(StringRef Str, Allocator &A) : S(Str.copy(A)) {}
298
299 ~DIEInlineString() = default;
300
301 /// Grab the string out of the object.
302 StringRef getString() const { return S; }
303
304 void emitValue(const AsmPrinter *AP, dwarf::Form Form) const;
305 unsigned SizeOf(const AsmPrinter *AP, dwarf::Form Form) const;
306
307 void print(raw_ostream &O) const;
308};
309
310//===--------------------------------------------------------------------===//
311/// A pointer to another debug information entry. An instance of this class can
312/// also be used as a proxy for a debug information entry not yet defined
313/// (ie. types.)
314class DIEEntry {
315 DIE *Entry;
316
317public:
318 DIEEntry() = delete;
319 explicit DIEEntry(DIE &E) : Entry(&E) {}
320
321 DIE &getEntry() const { return *Entry; }
322
323 void emitValue(const AsmPrinter *AP, dwarf::Form Form) const;
324 unsigned SizeOf(const AsmPrinter *AP, dwarf::Form Form) const;
325
326 void print(raw_ostream &O) const;
327};
328
329//===--------------------------------------------------------------------===//
330/// Represents a pointer to a location list in the debug_loc
331/// section.
332class DIELocList {
333 /// Index into the .debug_loc vector.
334 size_t Index;
335
336public:
337 DIELocList(size_t I) : Index(I) {}
338
339 /// Grab the current index out.
340 size_t getValue() const { return Index; }
341
342 void emitValue(const AsmPrinter *AP, dwarf::Form Form) const;
343 unsigned SizeOf(const AsmPrinter *AP, dwarf::Form Form) const;
344
345 void print(raw_ostream &O) const;
346};
347
348//===--------------------------------------------------------------------===//
349/// A BaseTypeRef DIE.
350class DIEAddrOffset {
351 DIEInteger Addr;
352 DIEDelta Offset;
353
354public:
355 explicit DIEAddrOffset(uint64_t Idx, const MCSymbol *Hi, const MCSymbol *Lo)
356 : Addr(Idx), Offset(Hi, Lo) {}
357
358 void emitValue(const AsmPrinter *AP, dwarf::Form Form) const;
359 unsigned SizeOf(const AsmPrinter *AP, dwarf::Form Form) const;
360
361 void print(raw_ostream &O) const;
362};
363
364//===--------------------------------------------------------------------===//
365/// A debug information entry value. Some of these roughly correlate
366/// to DWARF attribute classes.
367class DIEBlock;
368class DIELoc;
369class DIEValue {
370public:
371 enum Type {
372 isNone,
373#define HANDLE_DIEVALUE(T) is##T,
374#include "llvm/CodeGen/DIEValue.def"
375 };
376
377private:
378 /// Type of data stored in the value.
379 Type Ty = isNone;
380 dwarf::Attribute Attribute = (dwarf::Attribute)0;
381 dwarf::Form Form = (dwarf::Form)0;
382
383 /// Storage for the value.
384 ///
385 /// All values that aren't standard layout (or are larger than 8 bytes)
386 /// should be stored by reference instead of by value.
387 using ValTy =
388 AlignedCharArrayUnion<DIEInteger, DIEString, DIEExpr, DIELabel,
389 DIEDelta *, DIEEntry, DIEBlock *, DIELoc *,
390 DIELocList, DIEBaseTypeRef *, DIEAddrOffset *>;
391
392 static_assert(sizeof(ValTy) <= sizeof(uint64_t) ||
393 sizeof(ValTy) <= sizeof(void *),
394 "Expected all large types to be stored via pointer");
395
396 /// Underlying stored value.
397 ValTy Val;
398
399 template <class T> void construct(T V) {
400 static_assert(std::is_standard_layout<T>::value ||
401 std::is_pointer<T>::value,
402 "Expected standard layout or pointer");
403 new (reinterpret_cast<void *>(&Val)) T(V);
404 }
405
406 template <class T> T *get() { return reinterpret_cast<T *>(&Val); }
407 template <class T> const T *get() const {
408 return reinterpret_cast<const T *>(&Val);
409 }
410 template <class T> void destruct() { get<T>()->~T(); }
411
412 /// Destroy the underlying value.
413 ///
414 /// This should get optimized down to a no-op. We could skip it if we could
415 /// add a static assert on \a std::is_trivially_copyable(), but we currently
416 /// support versions of GCC that don't understand that.
417 void destroyVal() {
418 switch (Ty) {
419 case isNone:
420 return;
421#define HANDLE_DIEVALUE_SMALL(T) \
422 case is##T: \
423 destruct<DIE##T>(); \
424 return;
425#define HANDLE_DIEVALUE_LARGE(T) \
426 case is##T: \
427 destruct<const DIE##T *>(); \
428 return;
429#include "llvm/CodeGen/DIEValue.def"
430 }
431 }
432
433 /// Copy the underlying value.
434 ///
435 /// This should get optimized down to a simple copy. We need to actually
436 /// construct the value, rather than calling memcpy, to satisfy strict
437 /// aliasing rules.
438 void copyVal(const DIEValue &X) {
439 switch (Ty) {
440 case isNone:
441 return;
442#define HANDLE_DIEVALUE_SMALL(T) \
443 case is##T: \
444 construct<DIE##T>(*X.get<DIE##T>()); \
445 return;
446#define HANDLE_DIEVALUE_LARGE(T) \
447 case is##T: \
448 construct<const DIE##T *>(*X.get<const DIE##T *>()); \
449 return;
450#include "llvm/CodeGen/DIEValue.def"
451 }
452 }
453
454public:
455 DIEValue() = default;
456
457 DIEValue(const DIEValue &X) : Ty(X.Ty), Attribute(X.Attribute), Form(X.Form) {
458 copyVal(X);
459 }
460
461 DIEValue &operator=(const DIEValue &X) {
462 destroyVal();
463 Ty = X.Ty;
464 Attribute = X.Attribute;
465 Form = X.Form;
466 copyVal(X);
467 return *this;
468 }
469
470 ~DIEValue() { destroyVal(); }
471
472#define HANDLE_DIEVALUE_SMALL(T) \
473 DIEValue(dwarf::Attribute Attribute, dwarf::Form Form, const DIE##T &V) \
474 : Ty(is##T), Attribute(Attribute), Form(Form) { \
475 construct<DIE##T>(V); \
476 }
477#define HANDLE_DIEVALUE_LARGE(T) \
478 DIEValue(dwarf::Attribute Attribute, dwarf::Form Form, const DIE##T *V) \
479 : Ty(is##T), Attribute(Attribute), Form(Form) { \
480 assert(V && "Expected valid value")((void)0); \
481 construct<const DIE##T *>(V); \
482 }
483#include "llvm/CodeGen/DIEValue.def"
484
485 /// Accessors.
486 /// @{
487 Type getType() const { return Ty; }
488 dwarf::Attribute getAttribute() const { return Attribute; }
489 dwarf::Form getForm() const { return Form; }
490 explicit operator bool() const { return Ty; }
491 /// @}
492
493#define HANDLE_DIEVALUE_SMALL(T) \
494 const DIE##T &getDIE##T() const { \
495 assert(getType() == is##T && "Expected " #T)((void)0); \
496 return *get<DIE##T>(); \
497 }
498#define HANDLE_DIEVALUE_LARGE(T) \
499 const DIE##T &getDIE##T() const { \
500 assert(getType() == is##T && "Expected " #T)((void)0); \
501 return **get<const DIE##T *>(); \
502 }
503#include "llvm/CodeGen/DIEValue.def"
504
505 /// Emit value via the Dwarf writer.
506 void emitValue(const AsmPrinter *AP) const;
507
508 /// Return the size of a value in bytes.
509 unsigned SizeOf(const AsmPrinter *AP) const;
510
511 void print(raw_ostream &O) const;
512 void dump() const;
513};
514
515struct IntrusiveBackListNode {
516 PointerIntPair<IntrusiveBackListNode *, 1> Next;
517
518 IntrusiveBackListNode() : Next(this, true) {}
519
520 IntrusiveBackListNode *getNext() const {
521 return Next.getInt() ? nullptr : Next.getPointer();
522 }
523};
524
525struct IntrusiveBackListBase {
526 using Node = IntrusiveBackListNode;
527
528 Node *Last = nullptr;
529
530 bool empty() const { return !Last; }
531
532 void push_back(Node &N) {
533 assert(N.Next.getPointer() == &N && "Expected unlinked node")((void)0);
534 assert(N.Next.getInt() == true && "Expected unlinked node")((void)0);
535
536 if (Last) {
537 N.Next = Last->Next;
538 Last->Next.setPointerAndInt(&N, false);
539 }
540 Last = &N;
541 }
542
543 void push_front(Node &N) {
544 assert(N.Next.getPointer() == &N && "Expected unlinked node")((void)0);
545 assert(N.Next.getInt() == true && "Expected unlinked node")((void)0);
546
547 if (Last) {
548 N.Next.setPointerAndInt(Last->Next.getPointer(), false);
549 Last->Next.setPointerAndInt(&N, true);
550 } else {
551 Last = &N;
552 }
553 }
554};
555
556template <class T> class IntrusiveBackList : IntrusiveBackListBase {
557public:
558 using IntrusiveBackListBase::empty;
559
560 void push_back(T &N) { IntrusiveBackListBase::push_back(N); }
561 void push_front(T &N) { IntrusiveBackListBase::push_front(N); }
562 T &back() { return *static_cast<T *>(Last); }
563 const T &back() const { return *static_cast<T *>(Last); }
564 T &front() {
565 return *static_cast<T *>(Last ? Last->Next.getPointer() : nullptr);
566 }
567 const T &front() const {
568 return *static_cast<T *>(Last ? Last->Next.getPointer() : nullptr);
569 }
570
571 void takeNodes(IntrusiveBackList<T> &Other) {
572 if (Other.empty())
573 return;
574
575 T *FirstNode = static_cast<T *>(Other.Last->Next.getPointer());
576 T *IterNode = FirstNode;
577 do {
578 // Keep a pointer to the node and increment the iterator.
579 T *TmpNode = IterNode;
580 IterNode = static_cast<T *>(IterNode->Next.getPointer());
581
582 // Unlink the node and push it back to this list.
583 TmpNode->Next.setPointerAndInt(TmpNode, true);
584 push_back(*TmpNode);
585 } while (IterNode != FirstNode);
586
587 Other.Last = nullptr;
588 }
589
590 class const_iterator;
591 class iterator
592 : public iterator_facade_base<iterator, std::forward_iterator_tag, T> {
593 friend class const_iterator;
594
595 Node *N = nullptr;
596
597 public:
598 iterator() = default;
599 explicit iterator(T *N) : N(N) {}
600
601 iterator &operator++() {
602 N = N->getNext();
603 return *this;
604 }
605
606 explicit operator bool() const { return N; }
607 T &operator*() const { return *static_cast<T *>(N); }
608
609 bool operator==(const iterator &X) const { return N == X.N; }
610 };
611
612 class const_iterator
613 : public iterator_facade_base<const_iterator, std::forward_iterator_tag,
614 const T> {
615 const Node *N = nullptr;
616
617 public:
618 const_iterator() = default;
619 // Placate MSVC by explicitly scoping 'iterator'.
620 const_iterator(typename IntrusiveBackList<T>::iterator X) : N(X.N) {}
621 explicit const_iterator(const T *N) : N(N) {}
622
623 const_iterator &operator++() {
624 N = N->getNext();
625 return *this;
626 }
627
628 explicit operator bool() const { return N; }
629 const T &operator*() const { return *static_cast<const T *>(N); }
630
631 bool operator==(const const_iterator &X) const { return N == X.N; }
632 };
633
634 iterator begin() {
635 return Last ? iterator(static_cast<T *>(Last->Next.getPointer())) : end();
636 }
637 const_iterator begin() const {
638 return const_cast<IntrusiveBackList *>(this)->begin();
639 }
640 iterator end() { return iterator(); }
641 const_iterator end() const { return const_iterator(); }
642
643 static iterator toIterator(T &N) { return iterator(&N); }
644 static const_iterator toIterator(const T &N) { return const_iterator(&N); }
645};
646
647/// A list of DIE values.
648///
649/// This is a singly-linked list, but instead of reversing the order of
650/// insertion, we keep a pointer to the back of the list so we can push in
651/// order.
652///
653/// There are two main reasons to choose a linked list over a customized
654/// vector-like data structure.
655///
656/// 1. For teardown efficiency, we want DIEs to be BumpPtrAllocated. Using a
657/// linked list here makes this way easier to accomplish.
658/// 2. Carrying an extra pointer per \a DIEValue isn't expensive. 45% of DIEs
659/// have 2 or fewer values, and 90% have 5 or fewer. A vector would be
660/// over-allocated by 50% on average anyway, the same cost as the
661/// linked-list node.
662class DIEValueList {
663 struct Node : IntrusiveBackListNode {
664 DIEValue V;
665
666 explicit Node(DIEValue V) : V(V) {}
667 };
668
669 using ListTy = IntrusiveBackList<Node>;
670
671 ListTy List;
672
673public:
674 class const_value_iterator;
675 class value_iterator
676 : public iterator_adaptor_base<value_iterator, ListTy::iterator,
677 std::forward_iterator_tag, DIEValue> {
678 friend class const_value_iterator;
679
680 using iterator_adaptor =
681 iterator_adaptor_base<value_iterator, ListTy::iterator,
682 std::forward_iterator_tag, DIEValue>;
683
684 public:
685 value_iterator() = default;
686 explicit value_iterator(ListTy::iterator X) : iterator_adaptor(X) {}
687
688 explicit operator bool() const { return bool(wrapped()); }
689 DIEValue &operator*() const { return wrapped()->V; }
690 };
691
692 class const_value_iterator : public iterator_adaptor_base<
693 const_value_iterator, ListTy::const_iterator,
694 std::forward_iterator_tag, const DIEValue> {
695 using iterator_adaptor =
696 iterator_adaptor_base<const_value_iterator, ListTy::const_iterator,
697 std::forward_iterator_tag, const DIEValue>;
698
699 public:
700 const_value_iterator() = default;
701 const_value_iterator(DIEValueList::value_iterator X)
702 : iterator_adaptor(X.wrapped()) {}
703 explicit const_value_iterator(ListTy::const_iterator X)
704 : iterator_adaptor(X) {}
705
706 explicit operator bool() const { return bool(wrapped()); }
707 const DIEValue &operator*() const { return wrapped()->V; }
708 };
709
710 using value_range = iterator_range<value_iterator>;
711 using const_value_range = iterator_range<const_value_iterator>;
712
713 value_iterator addValue(BumpPtrAllocator &Alloc, const DIEValue &V) {
714 List.push_back(*new (Alloc) Node(V));
715 return value_iterator(ListTy::toIterator(List.back()));
716 }
717 template <class T>
718 value_iterator addValue(BumpPtrAllocator &Alloc, dwarf::Attribute Attribute,
719 dwarf::Form Form, T &&Value) {
720 return addValue(Alloc, DIEValue(Attribute, Form, std::forward<T>(Value)));
721 }
722
723 /// Take ownership of the nodes in \p Other, and append them to the back of
724 /// the list.
725 void takeValues(DIEValueList &Other) { List.takeNodes(Other.List); }
726
727 value_range values() {
728 return make_range(value_iterator(List.begin()), value_iterator(List.end()));
729 }
730 const_value_range values() const {
731 return make_range(const_value_iterator(List.begin()),
732 const_value_iterator(List.end()));
733 }
734};
735
736//===--------------------------------------------------------------------===//
737/// A structured debug information entry. Has an abbreviation which
738/// describes its organization.
739class DIE : IntrusiveBackListNode, public DIEValueList {
740 friend class IntrusiveBackList<DIE>;
741 friend class DIEUnit;
742
743 /// Dwarf unit relative offset.
744 unsigned Offset = 0;
745 /// Size of instance + children.
746 unsigned Size = 0;
747 unsigned AbbrevNumber = ~0u;
748 /// Dwarf tag code.
749 dwarf::Tag Tag = (dwarf::Tag)0;
750 /// Set to true to force a DIE to emit an abbreviation that says it has
751 /// children even when it doesn't. This is used for unit testing purposes.
752 bool ForceChildren = false;
753 /// Children DIEs.
754 IntrusiveBackList<DIE> Children;
755
756 /// The owner is either the parent DIE for children of other DIEs, or a
757 /// DIEUnit which contains this DIE as its unit DIE.
758 PointerUnion<DIE *, DIEUnit *> Owner;
759
760 explicit DIE(dwarf::Tag Tag) : Tag(Tag) {}
761
762public:
763 DIE() = delete;
764 DIE(const DIE &RHS) = delete;
765 DIE(DIE &&RHS) = delete;
766 DIE &operator=(const DIE &RHS) = delete;
767 DIE &operator=(const DIE &&RHS) = delete;
768
769 static DIE *get(BumpPtrAllocator &Alloc, dwarf::Tag Tag) {
770 return new (Alloc) DIE(Tag);
2
←
Calling 'operator new<llvm::MallocAllocator, 4096UL, 4096UL, 128UL>'
→
771 }
772
773 // Accessors.
774 unsigned getAbbrevNumber() const { return AbbrevNumber; }
775 dwarf::Tag getTag() const { return Tag; }
776 /// Get the compile/type unit relative offset of this DIE.
777 unsigned getOffset() const { return Offset; }
778 unsigned getSize() const { return Size; }
779 bool hasChildren() const { return ForceChildren || !Children.empty(); }
780 void setForceChildren(bool B) { ForceChildren = B; }
781
782 using child_iterator = IntrusiveBackList<DIE>::iterator;
783 using const_child_iterator = IntrusiveBackList<DIE>::const_iterator;
784 using child_range = iterator_range<child_iterator>;
785 using const_child_range = iterator_range<const_child_iterator>;
786
787 child_range children() {
788 return make_range(Children.begin(), Children.end());
789 }
790 const_child_range children() const {
791 return make_range(Children.begin(), Children.end());
792 }
793
794 DIE *getParent() const;
795
796 /// Generate the abbreviation for this DIE.
797 ///
798 /// Calculate the abbreviation for this, which should be uniqued and
799 /// eventually used to call \a setAbbrevNumber().
800 DIEAbbrev generateAbbrev() const;
801
802 /// Set the abbreviation number for this DIE.
803 void setAbbrevNumber(unsigned I) { AbbrevNumber = I; }
804
805 /// Get the absolute offset within the .debug_info or .debug_types section
806 /// for this DIE.
807 uint64_t getDebugSectionOffset() const;
808
809 /// Compute the offset of this DIE and all its children.
810 ///
811 /// This function gets called just before we are going to generate the debug
812 /// information and gives each DIE a chance to figure out its CU relative DIE
813 /// offset, unique its abbreviation and fill in the abbreviation code, and
814 /// return the unit offset that points to where the next DIE will be emitted
815 /// within the debug unit section. After this function has been called for all
816 /// DIE objects, the DWARF can be generated since all DIEs will be able to
817 /// properly refer to other DIE objects since all DIEs have calculated their
818 /// offsets.
819 ///
820 /// \param AP AsmPrinter to use when calculating sizes.
821 /// \param AbbrevSet the abbreviation used to unique DIE abbreviations.
822 /// \param CUOffset the compile/type unit relative offset in bytes.
823 /// \returns the offset for the DIE that follows this DIE within the
824 /// current compile/type unit.
825 unsigned computeOffsetsAndAbbrevs(const AsmPrinter *AP,
826 DIEAbbrevSet &AbbrevSet, unsigned CUOffset);
827
828 /// Climb up the parent chain to get the compile unit or type unit DIE that
829 /// this DIE belongs to.
830 ///
831 /// \returns the compile or type unit DIE that owns this DIE, or NULL if
832 /// this DIE hasn't been added to a unit DIE.
833 const DIE *getUnitDie() const;
834
835 /// Climb up the parent chain to get the compile unit or type unit that this
836 /// DIE belongs to.
837 ///
838 /// \returns the DIEUnit that represents the compile or type unit that owns
839 /// this DIE, or NULL if this DIE hasn't been added to a unit DIE.
840 DIEUnit *getUnit() const;
841
842 void setOffset(unsigned O) { Offset = O; }
843 void setSize(unsigned S) { Size = S; }
844
845 /// Add a child to the DIE.
846 DIE &addChild(DIE *Child) {
847 assert(!Child->getParent() && "Child should be orphaned")((void)0);
848 Child->Owner = this;
849 Children.push_back(*Child);
850 return Children.back();
851 }
852
853 DIE &addChildFront(DIE *Child) {
854 assert(!Child->getParent() && "Child should be orphaned")((void)0);
855 Child->Owner = this;
856 Children.push_front(*Child);
857 return Children.front();
858 }
859
860 /// Find a value in the DIE with the attribute given.
861 ///
862 /// Returns a default-constructed DIEValue (where \a DIEValue::getType()
863 /// gives \a DIEValue::isNone) if no such attribute exists.
864 DIEValue findAttribute(dwarf::Attribute Attribute) const;
865
866 void print(raw_ostream &O, unsigned IndentCount = 0) const;
867 void dump() const;
868};
869
870//===--------------------------------------------------------------------===//
871/// Represents a compile or type unit.
872class DIEUnit {
873 /// The compile unit or type unit DIE. This variable must be an instance of
874 /// DIE so that we can calculate the DIEUnit from any DIE by traversing the
875 /// parent backchain and getting the Unit DIE, and then casting itself to a
876 /// DIEUnit. This allows us to be able to find the DIEUnit for any DIE without
877 /// having to store a pointer to the DIEUnit in each DIE instance.
878 DIE Die;
879 /// The section this unit will be emitted in. This may or may not be set to
880 /// a valid section depending on the client that is emitting DWARF.
881 MCSection *Section;
882 uint64_t Offset; /// .debug_info or .debug_types absolute section offset.
883protected:
884 virtual ~DIEUnit() = default;
885
886public:
887 explicit DIEUnit(dwarf::Tag UnitTag);
888 DIEUnit(const DIEUnit &RHS) = delete;
889 DIEUnit(DIEUnit &&RHS) = delete;
890 void operator=(const DIEUnit &RHS) = delete;
891 void operator=(const DIEUnit &&RHS) = delete;
892 /// Set the section that this DIEUnit will be emitted into.
893 ///
894 /// This function is used by some clients to set the section. Not all clients
895 /// that emit DWARF use this section variable.
896 void setSection(MCSection *Section) {
897 assert(!this->Section)((void)0);
898 this->Section = Section;
899 }
900
901 virtual const MCSymbol *getCrossSectionRelativeBaseAddress() const {
902 return nullptr;
903 }
904
905 /// Return the section that this DIEUnit will be emitted into.
906 ///
907 /// \returns Section pointer which can be NULL.
908 MCSection *getSection() const { return Section; }
909 void setDebugSectionOffset(uint64_t O) { Offset = O; }
910 uint64_t getDebugSectionOffset() const { return Offset; }
911 DIE &getUnitDie() { return Die; }
912 const DIE &getUnitDie() const { return Die; }
913};
914
915struct BasicDIEUnit final : DIEUnit {
916 explicit BasicDIEUnit(dwarf::Tag UnitTag) : DIEUnit(UnitTag) {}
917};
918
919//===--------------------------------------------------------------------===//
920/// DIELoc - Represents an expression location.
921//
922class DIELoc : public DIEValueList {
923 mutable unsigned Size = 0; // Size in bytes excluding size header.
924
925public:
926 DIELoc() = default;
927
928 /// ComputeSize - Calculate the size of the location expression.
929 ///
930 unsigned ComputeSize(const AsmPrinter *AP) const;
931
932 // TODO: move setSize() and Size to DIEValueList.
933 void setSize(unsigned size) { Size = size; }
934
935 /// BestForm - Choose the best form for data.
936 ///
937 dwarf::Form BestForm(unsigned DwarfVersion) const {
938 if (DwarfVersion > 3)
939 return dwarf::DW_FORM_exprloc;
940 // Pre-DWARF4 location expressions were blocks and not exprloc.
941 if ((unsigned char)Size == Size)
942 return dwarf::DW_FORM_block1;
943 if ((unsigned short)Size == Size)
944 return dwarf::DW_FORM_block2;
945 if ((unsigned int)Size == Size)
946 return dwarf::DW_FORM_block4;
947 return dwarf::DW_FORM_block;
948 }
949
950 void emitValue(const AsmPrinter *Asm, dwarf::Form Form) const;
951 unsigned SizeOf(const AsmPrinter *AP, dwarf::Form Form) const;
952
953 void print(raw_ostream &O) const;
954};
955
956//===--------------------------------------------------------------------===//
957/// DIEBlock - Represents a block of values.
958//
959class DIEBlock : public DIEValueList {
960 mutable unsigned Size = 0; // Size in bytes excluding size header.
961
962public:
963 DIEBlock() = default;
964
965 /// ComputeSize - Calculate the size of the location expression.
966 ///
967 unsigned ComputeSize(const AsmPrinter *AP) const;
968
969 // TODO: move setSize() and Size to DIEValueList.
970 void setSize(unsigned size) { Size = size; }
971
972 /// BestForm - Choose the best form for data.
973 ///
974 dwarf::Form BestForm() const {
975 if ((unsigned char)Size == Size)
976 return dwarf::DW_FORM_block1;
977 if ((unsigned short)Size == Size)
978 return dwarf::DW_FORM_block2;
979 if ((unsigned int)Size == Size)
980 return dwarf::DW_FORM_block4;
981 return dwarf::DW_FORM_block;
982 }
983
984 void emitValue(const AsmPrinter *Asm, dwarf::Form Form) const;
985 unsigned SizeOf(const AsmPrinter *AP, dwarf::Form Form) const;
986
987 void print(raw_ostream &O) const;
988};
989
990} // end namespace llvm
991
992#endif // LLVM_CODEGEN_DIE_H
←

/usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Support/Allocator.h

→
1//===- Allocator.h - Simple memory allocation abstraction -------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8/// \file
9///
10/// This file defines the BumpPtrAllocator interface. BumpPtrAllocator conforms
11/// to the LLVM "Allocator" concept and is similar to MallocAllocator, but
12/// objects cannot be deallocated. Their lifetime is tied to the lifetime of the
13/// allocator.
14///
15//===----------------------------------------------------------------------===//
16
17#ifndef LLVM_SUPPORT_ALLOCATOR_H
18#define LLVM_SUPPORT_ALLOCATOR_H
19
20#include "llvm/ADT/Optional.h"
21#include "llvm/ADT/SmallVector.h"
22#include "llvm/Support/Alignment.h"
23#include "llvm/Support/AllocatorBase.h"
24#include "llvm/Support/Compiler.h"
25#include "llvm/Support/ErrorHandling.h"
26#include "llvm/Support/MathExtras.h"
27#include "llvm/Support/MemAlloc.h"
28#include <algorithm>
29#include <cassert>
30#include <cstddef>
31#include <cstdint>
32#include <cstdlib>
33#include <iterator>
34#include <type_traits>
35#include <utility>
36
37namespace llvm {
38
39namespace detail {
40
41// We call out to an external function to actually print the message as the
42// printing code uses Allocator.h in its implementation.
43void printBumpPtrAllocatorStats(unsigned NumSlabs, size_t BytesAllocated,
44 size_t TotalMemory);
45
46} // end namespace detail
47
48/// Allocate memory in an ever growing pool, as if by bump-pointer.
49///
50/// This isn't strictly a bump-pointer allocator as it uses backing slabs of
51/// memory rather than relying on a boundless contiguous heap. However, it has
52/// bump-pointer semantics in that it is a monotonically growing pool of memory
53/// where every allocation is found by merely allocating the next N bytes in
54/// the slab, or the next N bytes in the next slab.
55///
56/// Note that this also has a threshold for forcing allocations above a certain
57/// size into their own slab.
58///
59/// The BumpPtrAllocatorImpl template defaults to using a MallocAllocator
60/// object, which wraps malloc, to allocate memory, but it can be changed to
61/// use a custom allocator.
62///
63/// The GrowthDelay specifies after how many allocated slabs the allocator
64/// increases the size of the slabs.
65template <typename AllocatorT = MallocAllocator, size_t SlabSize = 4096,
66 size_t SizeThreshold = SlabSize, size_t GrowthDelay = 128>
67class BumpPtrAllocatorImpl
68 : public AllocatorBase<BumpPtrAllocatorImpl<AllocatorT, SlabSize,
69 SizeThreshold, GrowthDelay>>,
70 private AllocatorT {
71public:
72 static_assert(SizeThreshold <= SlabSize,
73 "The SizeThreshold must be at most the SlabSize to ensure "
74 "that objects larger than a slab go into their own memory "
75 "allocation.");
76 static_assert(GrowthDelay > 0,
77 "GrowthDelay must be at least 1 which already increases the"
78 "slab size after each allocated slab.");
79
80 BumpPtrAllocatorImpl() = default;
81
82 template <typename T>
83 BumpPtrAllocatorImpl(T &&Allocator)
84 : AllocatorT(std::forward<T &&>(Allocator)) {}
85
86 // Manually implement a move constructor as we must clear the old allocator's
87 // slabs as a matter of correctness.
88 BumpPtrAllocatorImpl(BumpPtrAllocatorImpl &&Old)
89 : AllocatorT(static_cast<AllocatorT &&>(Old)), CurPtr(Old.CurPtr),
90 End(Old.End), Slabs(std::move(Old.Slabs)),
91 CustomSizedSlabs(std::move(Old.CustomSizedSlabs)),
92 BytesAllocated(Old.BytesAllocated), RedZoneSize(Old.RedZoneSize) {
93 Old.CurPtr = Old.End = nullptr;
94 Old.BytesAllocated = 0;
95 Old.Slabs.clear();
96 Old.CustomSizedSlabs.clear();
97 }
98
99 ~BumpPtrAllocatorImpl() {
100 DeallocateSlabs(Slabs.begin(), Slabs.end());
101 DeallocateCustomSizedSlabs();
102 }
103
104 BumpPtrAllocatorImpl &operator=(BumpPtrAllocatorImpl &&RHS) {
105 DeallocateSlabs(Slabs.begin(), Slabs.end());
106 DeallocateCustomSizedSlabs();
107
108 CurPtr = RHS.CurPtr;
109 End = RHS.End;
110 BytesAllocated = RHS.BytesAllocated;
111 RedZoneSize = RHS.RedZoneSize;
112 Slabs = std::move(RHS.Slabs);
113 CustomSizedSlabs = std::move(RHS.CustomSizedSlabs);
114 AllocatorT::operator=(static_cast<AllocatorT &&>(RHS));
115
116 RHS.CurPtr = RHS.End = nullptr;
117 RHS.BytesAllocated = 0;
118 RHS.Slabs.clear();
119 RHS.CustomSizedSlabs.clear();
120 return *this;
121 }
122
123 /// Deallocate all but the current slab and reset the current pointer
124 /// to the beginning of it, freeing all memory allocated so far.
125 void Reset() {
126 // Deallocate all but the first slab, and deallocate all custom-sized slabs.
127 DeallocateCustomSizedSlabs();
128 CustomSizedSlabs.clear();
129
130 if (Slabs.empty())
131 return;
132
133 // Reset the state.
134 BytesAllocated = 0;
135 CurPtr = (char *)Slabs.front();
136 End = CurPtr + SlabSize;
137
138 __asan_poison_memory_region(*Slabs.begin(), computeSlabSize(0));
139 DeallocateSlabs(std::next(Slabs.begin()), Slabs.end());
140 Slabs.erase(std::next(Slabs.begin()), Slabs.end());
141 }
142
143 /// Allocate space at the specified alignment.
144 LLVM_ATTRIBUTE_RETURNS_NONNULL__attribute__((returns_nonnull)) LLVM_ATTRIBUTE_RETURNS_NOALIAS__attribute__((__malloc__)) void *
145 Allocate(size_t Size, Align Alignment) {
146 // Keep track of how many bytes we've allocated.
147 BytesAllocated += Size;
148
149 size_t Adjustment = offsetToAlignedAddr(CurPtr, Alignment);
5
←
Calling 'offsetToAlignedAddr'
→
150 assert(Adjustment + Size >= Size && "Adjustment + Size must not overflow")((void)0);
151
152 size_t SizeToAllocate = Size;
153#if LLVM_ADDRESS_SANITIZER_BUILD0
154 // Add trailing bytes as a "red zone" under ASan.
155 SizeToAllocate += RedZoneSize;
156#endif
157
158 // Check if we have enough space.
159 if (Adjustment + SizeToAllocate <= size_t(End - CurPtr)) {
160 char *AlignedPtr = CurPtr + Adjustment;
161 CurPtr = AlignedPtr + SizeToAllocate;
162 // Update the allocation point of this memory block in MemorySanitizer.
163 // Without this, MemorySanitizer messages for values originated from here
164 // will point to the allocation of the entire slab.
165 __msan_allocated_memory(AlignedPtr, Size);
166 // Similarly, tell ASan about this space.
167 __asan_unpoison_memory_region(AlignedPtr, Size);
168 return AlignedPtr;
169 }
170
171 // If Size is really big, allocate a separate slab for it.
172 size_t PaddedSize = SizeToAllocate + Alignment.value() - 1;
173 if (PaddedSize > SizeThreshold) {
174 void *NewSlab =
175 AllocatorT::Allocate(PaddedSize, alignof(std::max_align_t));
176 // We own the new slab and don't want anyone reading anyting other than
177 // pieces returned from this method. So poison the whole slab.
178 __asan_poison_memory_region(NewSlab, PaddedSize);
179 CustomSizedSlabs.push_back(std::make_pair(NewSlab, PaddedSize));
180
181 uintptr_t AlignedAddr = alignAddr(NewSlab, Alignment);
182 assert(AlignedAddr + Size <= (uintptr_t)NewSlab + PaddedSize)((void)0);
183 char *AlignedPtr = (char*)AlignedAddr;
184 __msan_allocated_memory(AlignedPtr, Size);
185 __asan_unpoison_memory_region(AlignedPtr, Size);
186 return AlignedPtr;
187 }
188
189 // Otherwise, start a new slab and try again.
190 StartNewSlab();
191 uintptr_t AlignedAddr = alignAddr(CurPtr, Alignment);
192 assert(AlignedAddr + SizeToAllocate <= (uintptr_t)End &&((void)0)
193 "Unable to allocate memory!")((void)0);
194 char *AlignedPtr = (char*)AlignedAddr;
195 CurPtr = AlignedPtr + SizeToAllocate;
196 __msan_allocated_memory(AlignedPtr, Size);
197 __asan_unpoison_memory_region(AlignedPtr, Size);
198 return AlignedPtr;
199 }
200
201 inline LLVM_ATTRIBUTE_RETURNS_NONNULL__attribute__((returns_nonnull)) LLVM_ATTRIBUTE_RETURNS_NOALIAS__attribute__((__malloc__)) void *
202 Allocate(size_t Size, size_t Alignment) {
203 assert(Alignment > 0 && "0-byte alignment is not allowed. Use 1 instead.")((void)0);
204 return Allocate(Size, Align(Alignment));
4
←
Calling 'BumpPtrAllocatorImpl::Allocate'
→
205 }
206
207 // Pull in base class overloads.
208 using AllocatorBase<BumpPtrAllocatorImpl>::Allocate;
209
210 // Bump pointer allocators are expected to never free their storage; and
211 // clients expect pointers to remain valid for non-dereferencing uses even
212 // after deallocation.
213 void Deallocate(const void *Ptr, size_t Size, size_t /*Alignment*/) {
214 __asan_poison_memory_region(Ptr, Size);
215 }
216
217 // Pull in base class overloads.
218 using AllocatorBase<BumpPtrAllocatorImpl>::Deallocate;
219
220 size_t GetNumSlabs() const { return Slabs.size() + CustomSizedSlabs.size(); }
221
222 /// \return An index uniquely and reproducibly identifying
223 /// an input pointer \p Ptr in the given allocator.
224 /// The returned value is negative iff the object is inside a custom-size
225 /// slab.
226 /// Returns an empty optional if the pointer is not found in the allocator.
227 llvm::Optional<int64_t> identifyObject(const void *Ptr) {
228 const char *P = static_cast<const char *>(Ptr);
229 int64_t InSlabIdx = 0;
230 for (size_t Idx = 0, E = Slabs.size(); Idx < E; Idx++) {
231 const char *S = static_cast<const char *>(Slabs[Idx]);
232 if (P >= S && P < S + computeSlabSize(Idx))
233 return InSlabIdx + static_cast<int64_t>(P - S);
234 InSlabIdx += static_cast<int64_t>(computeSlabSize(Idx));
235 }
236
237 // Use negative index to denote custom sized slabs.
238 int64_t InCustomSizedSlabIdx = -1;
239 for (size_t Idx = 0, E = CustomSizedSlabs.size(); Idx < E; Idx++) {
240 const char *S = static_cast<const char *>(CustomSizedSlabs[Idx].first);
241 size_t Size = CustomSizedSlabs[Idx].second;
242 if (P >= S && P < S + Size)
243 return InCustomSizedSlabIdx - static_cast<int64_t>(P - S);
244 InCustomSizedSlabIdx -= static_cast<int64_t>(Size);
245 }
246 return None;
247 }
248
249 /// A wrapper around identifyObject that additionally asserts that
250 /// the object is indeed within the allocator.
251 /// \return An index uniquely and reproducibly identifying
252 /// an input pointer \p Ptr in the given allocator.
253 int64_t identifyKnownObject(const void *Ptr) {
254 Optional<int64_t> Out = identifyObject(Ptr);
255 assert(Out && "Wrong allocator used")((void)0);
256 return *Out;
257 }
258
259 /// A wrapper around identifyKnownObject. Accepts type information
260 /// about the object and produces a smaller identifier by relying on
261 /// the alignment information. Note that sub-classes may have different
262 /// alignment, so the most base class should be passed as template parameter
263 /// in order to obtain correct results. For that reason automatic template
264 /// parameter deduction is disabled.
265 /// \return An index uniquely and reproducibly identifying
266 /// an input pointer \p Ptr in the given allocator. This identifier is
267 /// different from the ones produced by identifyObject and
268 /// identifyAlignedObject.
269 template <typename T>
270 int64_t identifyKnownAlignedObject(const void *Ptr) {
271 int64_t Out = identifyKnownObject(Ptr);
272 assert(Out % alignof(T) == 0 && "Wrong alignment information")((void)0);
273 return Out / alignof(T);
274 }
275
276 size_t getTotalMemory() const {
277 size_t TotalMemory = 0;
278 for (auto I = Slabs.begin(), E = Slabs.end(); I != E; ++I)
279 TotalMemory += computeSlabSize(std::distance(Slabs.begin(), I));
280 for (auto &PtrAndSize : CustomSizedSlabs)
281 TotalMemory += PtrAndSize.second;
282 return TotalMemory;
283 }
284
285 size_t getBytesAllocated() const { return BytesAllocated; }
286
287 void setRedZoneSize(size_t NewSize) {
288 RedZoneSize = NewSize;
289 }
290
291 void PrintStats() const {
292 detail::printBumpPtrAllocatorStats(Slabs.size(), BytesAllocated,
293 getTotalMemory());
294 }
295
296private:
297 /// The current pointer into the current slab.
298 ///
299 /// This points to the next free byte in the slab.
300 char *CurPtr = nullptr;
301
302 /// The end of the current slab.
303 char *End = nullptr;
304
305 /// The slabs allocated so far.
306 SmallVector<void *, 4> Slabs;
307
308 /// Custom-sized slabs allocated for too-large allocation requests.
309 SmallVector<std::pair<void *, size_t>, 0> CustomSizedSlabs;
310
311 /// How many bytes we've allocated.
312 ///
313 /// Used so that we can compute how much space was wasted.
314 size_t BytesAllocated = 0;
315
316 /// The number of bytes to put between allocations when running under
317 /// a sanitizer.
318 size_t RedZoneSize = 1;
319
320 static size_t computeSlabSize(unsigned SlabIdx) {
321 // Scale the actual allocated slab size based on the number of slabs
322 // allocated. Every GrowthDelay slabs allocated, we double
323 // the allocated size to reduce allocation frequency, but saturate at
324 // multiplying the slab size by 2^30.
325 return SlabSize *
326 ((size_t)1 << std::min<size_t>(30, SlabIdx / GrowthDelay));
327 }
328
329 /// Allocate a new slab and move the bump pointers over into the new
330 /// slab, modifying CurPtr and End.
331 void StartNewSlab() {
332 size_t AllocatedSlabSize = computeSlabSize(Slabs.size());
333
334 void *NewSlab =
335 AllocatorT::Allocate(AllocatedSlabSize, alignof(std::max_align_t));
336 // We own the new slab and don't want anyone reading anything other than
337 // pieces returned from this method. So poison the whole slab.
338 __asan_poison_memory_region(NewSlab, AllocatedSlabSize);
339
340 Slabs.push_back(NewSlab);
341 CurPtr = (char *)(NewSlab);
342 End = ((char *)NewSlab) + AllocatedSlabSize;
343 }
344
345 /// Deallocate a sequence of slabs.
346 void DeallocateSlabs(SmallVectorImpl<void *>::iterator I,
347 SmallVectorImpl<void *>::iterator E) {
348 for (; I != E; ++I) {
349 size_t AllocatedSlabSize =
350 computeSlabSize(std::distance(Slabs.begin(), I));
351 AllocatorT::Deallocate(*I, AllocatedSlabSize, alignof(std::max_align_t));
352 }
353 }
354
355 /// Deallocate all memory for custom sized slabs.
356 void DeallocateCustomSizedSlabs() {
357 for (auto &PtrAndSize : CustomSizedSlabs) {
358 void *Ptr = PtrAndSize.first;
359 size_t Size = PtrAndSize.second;
360 AllocatorT::Deallocate(Ptr, Size, alignof(std::max_align_t));
361 }
362 }
363
364 template <typename T> friend class SpecificBumpPtrAllocator;
365};
366
367/// The standard BumpPtrAllocator which just uses the default template
368/// parameters.
369typedef BumpPtrAllocatorImpl<> BumpPtrAllocator;
370
371/// A BumpPtrAllocator that allows only elements of a specific type to be
372/// allocated.
373///
374/// This allows calling the destructor in DestroyAll() and when the allocator is
375/// destroyed.
376template <typename T> class SpecificBumpPtrAllocator {
377 BumpPtrAllocator Allocator;
378
379public:
380 SpecificBumpPtrAllocator() {
381 // Because SpecificBumpPtrAllocator walks the memory to call destructors,
382 // it can't have red zones between allocations.
383 Allocator.setRedZoneSize(0);
384 }
385 SpecificBumpPtrAllocator(SpecificBumpPtrAllocator &&Old)
386 : Allocator(std::move(Old.Allocator)) {}
387 ~SpecificBumpPtrAllocator() { DestroyAll(); }
388
389 SpecificBumpPtrAllocator &operator=(SpecificBumpPtrAllocator &&RHS) {
390 Allocator = std::move(RHS.Allocator);
391 return *this;
392 }
393
394 /// Call the destructor of each allocated object and deallocate all but the
395 /// current slab and reset the current pointer to the beginning of it, freeing
396 /// all memory allocated so far.
397 void DestroyAll() {
398 auto DestroyElements = [](char *Begin, char *End) {
399 assert(Begin == (char *)alignAddr(Begin, Align::Of<T>()))((void)0);
400 for (char *Ptr = Begin; Ptr + sizeof(T) <= End; Ptr += sizeof(T))
401 reinterpret_cast<T *>(Ptr)->~T();
402 };
403
404 for (auto I = Allocator.Slabs.begin(), E = Allocator.Slabs.end(); I != E;
405 ++I) {
406 size_t AllocatedSlabSize = BumpPtrAllocator::computeSlabSize(
407 std::distance(Allocator.Slabs.begin(), I));
408 char *Begin = (char *)alignAddr(*I, Align::Of<T>());
409 char *End = *I == Allocator.Slabs.back() ? Allocator.CurPtr
410 : (char *)*I + AllocatedSlabSize;
411
412 DestroyElements(Begin, End);
413 }
414
415 for (auto &PtrAndSize : Allocator.CustomSizedSlabs) {
416 void *Ptr = PtrAndSize.first;
417 size_t Size = PtrAndSize.second;
418 DestroyElements((char *)alignAddr(Ptr, Align::Of<T>()),
419 (char *)Ptr + Size);
420 }
421
422 Allocator.Reset();
423 }
424
425 /// Allocate space for an array of objects without constructing them.
426 T *Allocate(size_t num = 1) { return Allocator.Allocate<T>(num); }
427};
428
429} // end namespace llvm
430
431template <typename AllocatorT, size_t SlabSize, size_t SizeThreshold,
432 size_t GrowthDelay>
433void *
434operator new(size_t Size,
435 llvm::BumpPtrAllocatorImpl<AllocatorT, SlabSize, SizeThreshold,
436 GrowthDelay> &Allocator) {
437 return Allocator.Allocate(Size, std::min((size_t)llvm::NextPowerOf2(Size),
3
←
Calling 'BumpPtrAllocatorImpl::Allocate'
→
438 alignof(std::max_align_t)));
439}
440
441template <typename AllocatorT, size_t SlabSize, size_t SizeThreshold,
442 size_t GrowthDelay>
443void operator delete(void *,
444 llvm::BumpPtrAllocatorImpl<AllocatorT, SlabSize,
445 SizeThreshold, GrowthDelay> &) {
446}
447
448#endif // LLVM_SUPPORT_ALLOCATOR_H
←

/usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Support/Alignment.h

1//===-- llvm/Support/Alignment.h - Useful alignment functions ---*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file contains types to represent alignments.
10// They are instrumented to guarantee some invariants are preserved and prevent
11// invalid manipulations.
12//
13// - Align represents an alignment in bytes, it is always set and always a valid
14// power of two, its minimum value is 1 which means no alignment requirements.
15//
16// - MaybeAlign is an optional type, it may be undefined or set. When it's set
17// you can get the underlying Align type by using the getValue() method.
18//
19//===----------------------------------------------------------------------===//
20
21#ifndef LLVM_SUPPORT_ALIGNMENT_H_
22#define LLVM_SUPPORT_ALIGNMENT_H_
23
24#include "llvm/ADT/Optional.h"
25#include "llvm/Support/MathExtras.h"
26#include <cassert>
27#ifndef NDEBUG1
28#include <string>
29#endif // NDEBUG
30
31namespace llvm {
32
33#define ALIGN_CHECK_ISPOSITIVE(decl) \
34 assert(decl > 0 && (#decl " should be defined"))((void)0)
35
36/// This struct is a compact representation of a valid (non-zero power of two)
37/// alignment.
38/// It is suitable for use as static global constants.
39struct Align {
40private:
41 uint8_t ShiftValue = 0; /// The log2 of the required alignment.
42 /// ShiftValue is less than 64 by construction.
43
44 friend struct MaybeAlign;
45 friend unsigned Log2(Align);
46 friend bool operator==(Align Lhs, Align Rhs);
47 friend bool operator!=(Align Lhs, Align Rhs);
48 friend bool operator<=(Align Lhs, Align Rhs);
49 friend bool operator>=(Align Lhs, Align Rhs);
50 friend bool operator<(Align Lhs, Align Rhs);
51 friend bool operator>(Align Lhs, Align Rhs);
52 friend unsigned encode(struct MaybeAlign A);
53 friend struct MaybeAlign decodeMaybeAlign(unsigned Value);
54
55 /// A trivial type to allow construction of constexpr Align.
56 /// This is currently needed to workaround a bug in GCC 5.3 which prevents
57 /// definition of constexpr assign operators.
58 /// https://stackoverflow.com/questions/46756288/explicitly-defaulted-function-cannot-be-declared-as-constexpr-because-the-implic
59 /// FIXME: Remove this, make all assign operators constexpr and introduce user
60 /// defined literals when we don't have to support GCC 5.3 anymore.
61 /// https://llvm.org/docs/GettingStarted.html#getting-a-modern-host-c-toolchain
62 struct LogValue {
63 uint8_t Log;
64 };
65
66public:
67 /// Default is byte-aligned.
68 constexpr Align() = default;
69 /// Do not perform checks in case of copy/move construct/assign, because the
70 /// checks have been performed when building `Other`.
71 constexpr Align(const Align &Other) = default;
72 constexpr Align(Align &&Other) = default;
73 Align &operator=(const Align &Other) = default;
74 Align &operator=(Align &&Other) = default;
75
76 explicit Align(uint64_t Value) {
77 assert(Value > 0 && "Value must not be 0")((void)0);
78 assert(llvm::isPowerOf2_64(Value) && "Alignment is not a power of 2")((void)0);
79 ShiftValue = Log2_64(Value);
80 assert(ShiftValue < 64 && "Broken invariant")((void)0);
81 }
82
83 /// This is a hole in the type system and should not be abused.
84 /// Needed to interact with C for instance.
85 uint64_t value() const { return uint64_t(1) << ShiftValue; }
10
←
The result of the left shift is undefined due to shifting by '255', which is greater or equal to the width of type 'uint64_t'
86
87 /// Allow constructions of constexpr Align.
88 template <size_t kValue> constexpr static LogValue Constant() {
89 return LogValue{static_cast<uint8_t>(CTLog2<kValue>())};
90 }
91
92 /// Allow constructions of constexpr Align from types.
93 /// Compile time equivalent to Align(alignof(T)).
94 template <typename T> constexpr static LogValue Of() {
95 return Constant<std::alignment_of<T>::value>();
96 }
97
98 /// Constexpr constructor from LogValue type.
99 constexpr Align(LogValue CA) : ShiftValue(CA.Log) {}
100};
101
102/// Treats the value 0 as a 1, so Align is always at least 1.
103inline Align assumeAligned(uint64_t Value) {
104 return Value ? Align(Value) : Align();
105}
106
107/// This struct is a compact representation of a valid (power of two) or
108/// undefined (0) alignment.
109struct MaybeAlign : public llvm::Optional<Align> {
110private:
111 using UP = llvm::Optional<Align>;
112
113public:
114 /// Default is undefined.
115 MaybeAlign() = default;
116 /// Do not perform checks in case of copy/move construct/assign, because the
117 /// checks have been performed when building `Other`.
118 MaybeAlign(const MaybeAlign &Other) = default;
119 MaybeAlign &operator=(const MaybeAlign &Other) = default;
120 MaybeAlign(MaybeAlign &&Other) = default;
121 MaybeAlign &operator=(MaybeAlign &&Other) = default;
122
123 /// Use llvm::Optional<Align> constructor.
124 using UP::UP;
125
126 explicit MaybeAlign(uint64_t Value) {
127 assert((Value == 0 || llvm::isPowerOf2_64(Value)) &&((void)0)
128 "Alignment is neither 0 nor a power of 2")((void)0);
129 if (Value)
130 emplace(Value);
131 }
132
133 /// For convenience, returns a valid alignment or 1 if undefined.
134 Align valueOrOne() const { return hasValue() ? getValue() : Align(); }
135};
136
137/// Checks that SizeInBytes is a multiple of the alignment.
138inline bool isAligned(Align Lhs, uint64_t SizeInBytes) {
139 return SizeInBytes % Lhs.value() == 0;
140}
141
142/// Checks that Addr is a multiple of the alignment.
143inline bool isAddrAligned(Align Lhs, const void *Addr) {
144 return isAligned(Lhs, reinterpret_cast<uintptr_t>(Addr));
145}
146
147/// Returns a multiple of A needed to store `Size` bytes.
148inline uint64_t alignTo(uint64_t Size, Align A) {
149 const uint64_t Value = A.value();
9
←
Calling 'Align::value'
→
150 // The following line is equivalent to `(Size + Value - 1) / Value * Value`.
151
152 // The division followed by a multiplication can be thought of as a right
153 // shift followed by a left shift which zeros out the extra bits produced in
154 // the bump; `~(Value - 1)` is a mask where all those bits being zeroed out
155 // are just zero.
156
157 // Most compilers can generate this code but the pattern may be missed when
158 // multiple functions gets inlined.
159 return (Size + Value - 1) & ~(Value - 1U);
160}
161
162/// If non-zero \p Skew is specified, the return value will be a minimal integer
163/// that is greater than or equal to \p Size and equal to \p A * N + \p Skew for
164/// some integer N. If \p Skew is larger than \p A, its value is adjusted to '\p
165/// Skew mod \p A'.
166///
167/// Examples:
168/// \code
169/// alignTo(5, Align(8), 7) = 7
170/// alignTo(17, Align(8), 1) = 17
171/// alignTo(~0LL, Align(8), 3) = 3
172/// \endcode
173inline uint64_t alignTo(uint64_t Size, Align A, uint64_t Skew) {
174 const uint64_t Value = A.value();
175 Skew %= Value;
176 return ((Size + Value - 1 - Skew) & ~(Value - 1U)) + Skew;
177}
178
179/// Returns a multiple of A needed to store `Size` bytes.
180/// Returns `Size` if current alignment is undefined.
181inline uint64_t alignTo(uint64_t Size, MaybeAlign A) {
182 return A ? alignTo(Size, A.getValue()) : Size;
183}
184
185/// Aligns `Addr` to `Alignment` bytes, rounding up.
186inline uintptr_t alignAddr(const void *Addr, Align Alignment) {
187 uintptr_t ArithAddr = reinterpret_cast<uintptr_t>(Addr);
188 assert(static_cast<uintptr_t>(ArithAddr + Alignment.value() - 1) >=((void)0)
189 ArithAddr &&((void)0)
190 "Overflow")((void)0);
191 return alignTo(ArithAddr, Alignment);
192}
193
194/// Returns the offset to the next integer (mod 2**64) that is greater than
195/// or equal to \p Value and is a multiple of \p Align.
196inline uint64_t offsetToAlignment(uint64_t Value, Align Alignment) {
197 return alignTo(Value, Alignment) - Value;
7
←
The value 255 is assigned to 'A.ShiftValue'
→
8
←
Calling 'alignTo'
→
198}
199
200/// Returns the necessary adjustment for aligning `Addr` to `Alignment`
201/// bytes, rounding up.
202inline uint64_t offsetToAlignedAddr(const void *Addr, Align Alignment) {
203 return offsetToAlignment(reinterpret_cast<uintptr_t>(Addr), Alignment);
6
←
Calling 'offsetToAlignment'
→
204}
205
206/// Returns the log2 of the alignment.
207inline unsigned Log2(Align A) { return A.ShiftValue; }
208
209/// Returns the alignment that satisfies both alignments.
210/// Same semantic as MinAlign.
211inline Align commonAlignment(Align A, Align B) { return std::min(A, B); }
212
213/// Returns the alignment that satisfies both alignments.
214/// Same semantic as MinAlign.
215inline Align commonAlignment(Align A, uint64_t Offset) {
216 return Align(MinAlign(A.value(), Offset));
217}
218
219/// Returns the alignment that satisfies both alignments.
220/// Same semantic as MinAlign.
221inline MaybeAlign commonAlignment(MaybeAlign A, MaybeAlign B) {
222 return A && B ? commonAlignment(*A, *B) : A ? A : B;
223}
224
225/// Returns the alignment that satisfies both alignments.
226/// Same semantic as MinAlign.
227inline MaybeAlign commonAlignment(MaybeAlign A, uint64_t Offset) {
228 return MaybeAlign(MinAlign((*A).value(), Offset));
229}
230
231/// Returns a representation of the alignment that encodes undefined as 0.
232inline unsigned encode(MaybeAlign A) { return A ? A->ShiftValue + 1 : 0; }
233
234/// Dual operation of the encode function above.
235inline MaybeAlign decodeMaybeAlign(unsigned Value) {
236 if (Value == 0)
237 return MaybeAlign();
238 Align Out;
239 Out.ShiftValue = Value - 1;
240 return Out;
241}
242
243/// Returns a representation of the alignment, the encoded value is positive by
244/// definition.
245inline unsigned encode(Align A) { return encode(MaybeAlign(A)); }
246
247/// Comparisons between Align and scalars. Rhs must be positive.
248inline bool operator==(Align Lhs, uint64_t Rhs) {
249 ALIGN_CHECK_ISPOSITIVE(Rhs);
250 return Lhs.value() == Rhs;
251}
252inline bool operator!=(Align Lhs, uint64_t Rhs) {
253 ALIGN_CHECK_ISPOSITIVE(Rhs);
254 return Lhs.value() != Rhs;
255}
256inline bool operator<=(Align Lhs, uint64_t Rhs) {
257 ALIGN_CHECK_ISPOSITIVE(Rhs);
258 return Lhs.value() <= Rhs;
259}
260inline bool operator>=(Align Lhs, uint64_t Rhs) {
261 ALIGN_CHECK_ISPOSITIVE(Rhs);
262 return Lhs.value() >= Rhs;
263}
264inline bool operator<(Align Lhs, uint64_t Rhs) {
265 ALIGN_CHECK_ISPOSITIVE(Rhs);
266 return Lhs.value() < Rhs;
267}
268inline bool operator>(Align Lhs, uint64_t Rhs) {
269 ALIGN_CHECK_ISPOSITIVE(Rhs);
270 return Lhs.value() > Rhs;
271}
272
273/// Comparisons between MaybeAlign and scalars.
274inline bool operator==(MaybeAlign Lhs, uint64_t Rhs) {
275 return Lhs ? (*Lhs).value() == Rhs : Rhs == 0;
276}
277inline bool operator!=(MaybeAlign Lhs, uint64_t Rhs) {
278 return Lhs ? (*Lhs).value() != Rhs : Rhs != 0;
279}
280
281/// Comparisons operators between Align.
282inline bool operator==(Align Lhs, Align Rhs) {
283 return Lhs.ShiftValue == Rhs.ShiftValue;
284}
285inline bool operator!=(Align Lhs, Align Rhs) {
286 return Lhs.ShiftValue != Rhs.ShiftValue;
287}
288inline bool operator<=(Align Lhs, Align Rhs) {
289 return Lhs.ShiftValue <= Rhs.ShiftValue;
290}
291inline bool operator>=(Align Lhs, Align Rhs) {
292 return Lhs.ShiftValue >= Rhs.ShiftValue;
293}
294inline bool operator<(Align Lhs, Align Rhs) {
295 return Lhs.ShiftValue < Rhs.ShiftValue;
296}
297inline bool operator>(Align Lhs, Align Rhs) {
298 return Lhs.ShiftValue > Rhs.ShiftValue;
299}
300
301// Don't allow relational comparisons with MaybeAlign.
302bool operator<=(Align Lhs, MaybeAlign Rhs) = delete;
303bool operator>=(Align Lhs, MaybeAlign Rhs) = delete;
304bool operator<(Align Lhs, MaybeAlign Rhs) = delete;
305bool operator>(Align Lhs, MaybeAlign Rhs) = delete;
306
307bool operator<=(MaybeAlign Lhs, Align Rhs) = delete;
308bool operator>=(MaybeAlign Lhs, Align Rhs) = delete;
309bool operator<(MaybeAlign Lhs, Align Rhs) = delete;
310bool operator>(MaybeAlign Lhs, Align Rhs) = delete;
311
312bool operator<=(MaybeAlign Lhs, MaybeAlign Rhs) = delete;
313bool operator>=(MaybeAlign Lhs, MaybeAlign Rhs) = delete;
314bool operator<(MaybeAlign Lhs, MaybeAlign Rhs) = delete;
315bool operator>(MaybeAlign Lhs, MaybeAlign Rhs) = delete;
316
317inline Align operator*(Align Lhs, uint64_t Rhs) {
318 assert(Rhs > 0 && "Rhs must be positive")((void)0);
319 return Align(Lhs.value() * Rhs);
320}
321
322inline MaybeAlign operator*(MaybeAlign Lhs, uint64_t Rhs) {
323 assert(Rhs > 0 && "Rhs must be positive")((void)0);
324 return Lhs ? Lhs.getValue() * Rhs : MaybeAlign();
325}
326
327inline Align operator/(Align Lhs, uint64_t Divisor) {
328 assert(llvm::isPowerOf2_64(Divisor) &&((void)0)
329 "Divisor must be positive and a power of 2")((void)0);
330 assert(Lhs != 1 && "Can't halve byte alignment")((void)0);
331 return Align(Lhs.value() / Divisor);
332}
333
334inline MaybeAlign operator/(MaybeAlign Lhs, uint64_t Divisor) {
335 assert(llvm::isPowerOf2_64(Divisor) &&((void)0)
336 "Divisor must be positive and a power of 2")((void)0);
337 return Lhs ? Lhs.getValue() / Divisor : MaybeAlign();
338}
339
340inline Align max(MaybeAlign Lhs, Align Rhs) {
341 return Lhs && *Lhs > Rhs ? *Lhs : Rhs;
342}
343
344inline Align max(Align Lhs, MaybeAlign Rhs) {
345 return Rhs && *Rhs > Lhs ? *Rhs : Lhs;
346}
347
348#ifndef NDEBUG1
349// For usage in LLVM_DEBUG macros.
350inline std::string DebugStr(const Align &A) {
351 return std::to_string(A.value());
352}
353// For usage in LLVM_DEBUG macros.
354inline std::string DebugStr(const MaybeAlign &MA) {
355 if (MA)
356 return std::to_string(MA->value());
357 return "None";
358}
359#endif // NDEBUG
360
361#undef ALIGN_CHECK_ISPOSITIVE
362
363} // namespace llvm
364
365#endif // LLVM_SUPPORT_ALIGNMENT_H_