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

Bug Summary

File:	src/gnu/usr.bin/clang/libclangAST/../../../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'

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clang -cc1 -cc1 -triple amd64-unknown-openbsd7.0 -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name RawCommentList.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 static -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/libclangAST/obj -resource-dir /usr/local/lib/clang/13.0.0 -I /usr/src/gnu/usr.bin/clang/libclangAST/obj/../include/clang/AST -I /usr/src/gnu/usr.bin/clang/libclangAST/../../../llvm/clang/include -I /usr/src/gnu/usr.bin/clang/libclangAST/../../../llvm/llvm/include -I /usr/src/gnu/usr.bin/clang/libclangAST/../include -I /usr/src/gnu/usr.bin/clang/libclangAST/obj -I /usr/src/gnu/usr.bin/clang/libclangAST/obj/../include -D NDEBUG -D __STDC_LIMIT_MACROS -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D LLVM_PREFIX="/usr" -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/libclangAST/obj -ferror-limit 19 -fvisibility-inlines-hidden -fwrapv -stack-protector 2 -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/libclangAST/../../../llvm/clang/lib/AST/RawCommentList.cpp

/usr/src/gnu/usr.bin/clang/libclangAST/../../../llvm/clang/lib/AST/RawCommentList.cpp

→

1//===--- RawCommentList.cpp - Processing raw comments -----------*- 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//===----------------------------------------------------------------------===//

9#include "clang/AST/RawCommentList.h"
10#include "clang/AST/ASTContext.h"
11#include "clang/AST/Comment.h"
12#include "clang/AST/CommentBriefParser.h"
13#include "clang/AST/CommentCommandTraits.h"
14#include "clang/AST/CommentLexer.h"
15#include "clang/AST/CommentParser.h"
16#include "clang/AST/CommentSema.h"
17#include "clang/Basic/CharInfo.h"
18#include "llvm/ADT/STLExtras.h"
19#include "llvm/Support/Allocator.h"

21using namespace clang;

23namespace {
24/// Get comment kind and bool describing if it is a trailing comment.
25std::pair<RawComment::CommentKind, bool> getCommentKind(StringRef Comment,
                                                      bool ParseAllComments) {
const size_t MinCommentLength = ParseAllComments ? 2 : 3;
if ((Comment.size() < MinCommentLength) || Comment[0] != '/')
  return std::make_pair(RawComment::RCK_Invalid, false);

RawComment::CommentKind K;
if (Comment[1] == '/') {
  if (Comment.size() < 3)
    return std::make_pair(RawComment::RCK_OrdinaryBCPL, false);

  if (Comment[2] == '/')
    K = RawComment::RCK_BCPLSlash;
  else if (Comment[2] == '!')
    K = RawComment::RCK_BCPLExcl;
  else
    return std::make_pair(RawComment::RCK_OrdinaryBCPL, false);
} else {
  assert(Comment.size() >= 4)((void)0);

  // Comment lexer does not understand escapes in comment markers, so pretend
  // that this is not a comment.
  if (Comment[1] != '*' ||
      Comment[Comment.size() - 2] != '*' ||
      Comment[Comment.size() - 1] != '/')
    return std::make_pair(RawComment::RCK_Invalid, false);

  if (Comment[2] == '*')
    K = RawComment::RCK_JavaDoc;
  else if (Comment[2] == '!')
    K = RawComment::RCK_Qt;
  else
    return std::make_pair(RawComment::RCK_OrdinaryC, false);
}
const bool TrailingComment = (Comment.size() > 3) && (Comment[3] == '<');
return std::make_pair(K, TrailingComment);
61}

63bool mergedCommentIsTrailingComment(StringRef Comment) {
return (Comment.size() > 3) && (Comment[3] == '<');
65}

67/// Returns true if R1 and R2 both have valid locations that start on the same
68/// column.
69bool commentsStartOnSameColumn(const SourceManager &SM, const RawComment &R1,
                             const RawComment &R2) {
SourceLocation L1 = R1.getBeginLoc();
SourceLocation L2 = R2.getBeginLoc();
bool Invalid = false;
unsigned C1 = SM.getPresumedColumnNumber(L1, &Invalid);
if (!Invalid) {
  unsigned C2 = SM.getPresumedColumnNumber(L2, &Invalid);
  return !Invalid && (C1 == C2);
}
return false;
80}
81} // unnamed namespace

83/// Determines whether there is only whitespace in `Buffer` between `P`
84/// and the previous line.
85/// \param Buffer The buffer to search in.
86/// \param P The offset from the beginning of `Buffer` to start from.
87/// \return true if all of the characters in `Buffer` ranging from the closest
88/// line-ending character before `P` (or the beginning of `Buffer`) to `P - 1`
89/// are whitespace.
90static bool onlyWhitespaceOnLineBefore(const char *Buffer, unsigned P) {
// Search backwards until we see linefeed or carriage return.
for (unsigned I = P; I != 0; --I) {
  char C = Buffer[I - 1];
  if (isVerticalWhitespace(C))
    return true;
  if (!isHorizontalWhitespace(C))
    return false;
}
// We hit the beginning of the buffer.
return true;
101}

103/// Returns whether `K` is an ordinary comment kind.
104static bool isOrdinaryKind(RawComment::CommentKind K) {
return (K == RawComment::RCK_OrdinaryBCPL) ||
       (K == RawComment::RCK_OrdinaryC);
107}

109RawComment::RawComment(const SourceManager &SourceMgr, SourceRange SR,
                     const CommentOptions &CommentOpts, bool Merged) :
  Range(SR), RawTextValid(false), BriefTextValid(false),
  IsAttached(false), IsTrailingComment(false),
  IsAlmostTrailingComment(false) {
// Extract raw comment text, if possible.
if (SR.getBegin() == SR.getEnd() || getRawText(SourceMgr).empty()) {
  Kind = RCK_Invalid;
  return;
}

// Guess comment kind.
std::pair<CommentKind, bool> K =
    getCommentKind(RawText, CommentOpts.ParseAllComments);

// Guess whether an ordinary comment is trailing.
if (CommentOpts.ParseAllComments && isOrdinaryKind(K.first)) {
  FileID BeginFileID;
  unsigned BeginOffset;
  std::tie(BeginFileID, BeginOffset) =
      SourceMgr.getDecomposedLoc(Range.getBegin());
  if (BeginOffset != 0) {
    bool Invalid = false;
    const char *Buffer =
        SourceMgr.getBufferData(BeginFileID, &Invalid).data();
    IsTrailingComment |=
        (!Invalid && !onlyWhitespaceOnLineBefore(Buffer, BeginOffset));
  }
}

if (!Merged) {
  Kind = K.first;
  IsTrailingComment |= K.second;

  IsAlmostTrailingComment = RawText.startswith("//<") ||
                               RawText.startswith("/*<");
} else {
  Kind = RCK_Merged;
  IsTrailingComment =
      IsTrailingComment || mergedCommentIsTrailingComment(RawText);
}
150}

152StringRef RawComment::getRawTextSlow(const SourceManager &SourceMgr) const {
FileID BeginFileID;
FileID EndFileID;
unsigned BeginOffset;
unsigned EndOffset;

std::tie(BeginFileID, BeginOffset) =
    SourceMgr.getDecomposedLoc(Range.getBegin());
std::tie(EndFileID, EndOffset) = SourceMgr.getDecomposedLoc(Range.getEnd());

const unsigned Length = EndOffset - BeginOffset;
if (Length < 2)
  return StringRef();

// The comment can't begin in one file and end in another.
assert(BeginFileID == EndFileID)((void)0);

bool Invalid = false;
const char *BufferStart = SourceMgr.getBufferData(BeginFileID,
                                                  &Invalid).data();
if (Invalid)
  return StringRef();

return StringRef(BufferStart + BeginOffset, Length);
176}

178const char *RawComment::extractBriefText(const ASTContext &Context) const {
// Lazily initialize RawText using the accessor before using it.
(void)getRawText(Context.getSourceManager());

// Since we will be copying the resulting text, all allocations made during
// parsing are garbage after resulting string is formed.  Thus we can use
// a separate allocator for all temporary stuff.
llvm::BumpPtrAllocator Allocator;

comments::Lexer L(Allocator, Context.getDiagnostics(),
                  Context.getCommentCommandTraits(),
                  Range.getBegin(),
                  RawText.begin(), RawText.end());
comments::BriefParser P(L, Context.getCommentCommandTraits());

const std::string Result = P.Parse();
const unsigned BriefTextLength = Result.size();
char *BriefTextPtr = new (Context) char[BriefTextLength + 1];
memcpy(BriefTextPtr, Result.c_str(), BriefTextLength + 1);
BriefText = BriefTextPtr;
BriefTextValid = true;

return BriefTextPtr;
201}

203comments::FullComment *RawComment::parse(const ASTContext &Context,
                                       const Preprocessor *PP,
                                       const Decl *D) const {
// Lazily initialize RawText using the accessor before using it.
(void)getRawText(Context.getSourceManager());

comments::Lexer L(Context.getAllocator(), Context.getDiagnostics(),
                  Context.getCommentCommandTraits(),
                  getSourceRange().getBegin(),
                  RawText.begin(), RawText.end());
comments::Sema S(Context.getAllocator(), Context.getSourceManager(),
                 Context.getDiagnostics(),
                 Context.getCommentCommandTraits(),
                 PP);
S.setDecl(D);
comments::Parser P(L, S, Context.getAllocator(), Context.getSourceManager(),
                   Context.getDiagnostics(),
                   Context.getCommentCommandTraits());

return P.parseFullComment();
223}

225static bool onlyWhitespaceBetween(SourceManager &SM,
                                SourceLocation Loc1, SourceLocation Loc2,
                                unsigned MaxNewlinesAllowed) {
std::pair<FileID, unsigned> Loc1Info = SM.getDecomposedLoc(Loc1);
std::pair<FileID, unsigned> Loc2Info = SM.getDecomposedLoc(Loc2);

// Question does not make sense if locations are in different files.
if (Loc1Info.first != Loc2Info.first)
  return false;

bool Invalid = false;
const char *Buffer = SM.getBufferData(Loc1Info.first, &Invalid).data();
if (Invalid)
  return false;

unsigned NumNewlines = 0;
assert(Loc1Info.second <= Loc2Info.second && "Loc1 after Loc2!")((void)0);
// Look for non-whitespace characters and remember any newlines seen.
for (unsigned I = Loc1Info.second; I != Loc2Info.second; ++I) {
  switch (Buffer[I]) {
  default:
    return false;
  case ' ':
  case '\t':
  case '\f':
  case '\v':
    break;
  case '\r':
  case '\n':
    ++NumNewlines;

    // Check if we have found more than the maximum allowed number of
    // newlines.
    if (NumNewlines > MaxNewlinesAllowed)
      return false;

    // Collapse \r\n and \n\r into a single newline.
    if (I + 1 != Loc2Info.second &&
        (Buffer[I + 1] == '\n' || Buffer[I + 1] == '\r') &&
        Buffer[I] != Buffer[I + 1])
      ++I;
    break;
  }
}

return true;
271}

273void RawCommentList::addComment(const RawComment &RC,
                              const CommentOptions &CommentOpts,
                              llvm::BumpPtrAllocator &Allocator) {
if (RC.isInvalid())
1
Taking false branch→
  return;

// Ordinary comments are not interesting for us.
if (RC.isOrdinary() && !CommentOpts.ParseAllComments)
  return;

std::pair<FileID, unsigned> Loc =
    SourceMgr.getDecomposedLoc(RC.getBeginLoc());

const FileID CommentFile = Loc.first;
const unsigned CommentOffset = Loc.second;

// If this is the first Doxygen comment, save it (because there isn't
// anything to merge it with).
if (OrderedComments[CommentFile].empty()) {
2
←
Assuming the condition is true→
3
←
Taking true branch→
  OrderedComments[CommentFile][CommentOffset] =
      new (Allocator) RawComment(RC);
4
←
Calling 'operator new<llvm::MallocAllocator, 4096UL, 4096UL, 128UL>'→
  return;
}

const RawComment &C1 = *OrderedComments[CommentFile].rbegin()->second;
const RawComment &C2 = RC;

// Merge comments only if there is only whitespace between them.
// Can't merge trailing and non-trailing comments unless the second is
// non-trailing ordinary in the same column, as in the case:
//   int x; // documents x
//          // more text
// versus:
//   int x; // documents x
//   int y; // documents y
// or:
//   int x; // documents x
//   // documents y
//   int y;
// Merge comments if they are on same or consecutive lines.
if ((C1.isTrailingComment() == C2.isTrailingComment() ||
     (C1.isTrailingComment() && !C2.isTrailingComment() &&
      isOrdinaryKind(C2.getKind()) &&
      commentsStartOnSameColumn(SourceMgr, C1, C2))) &&
    onlyWhitespaceBetween(SourceMgr, C1.getEndLoc(), C2.getBeginLoc(),
                          /*MaxNewlinesAllowed=*/1)) {
  SourceRange MergedRange(C1.getBeginLoc(), C2.getEndLoc());
  *OrderedComments[CommentFile].rbegin()->second =
      RawComment(SourceMgr, MergedRange, CommentOpts, true);
} else {
  OrderedComments[CommentFile][CommentOffset] =
      new (Allocator) RawComment(RC);
}
326}

328const std::map<unsigned, RawComment *> *
329RawCommentList::getCommentsInFile(FileID File) const {
auto CommentsInFile = OrderedComments.find(File);
if (CommentsInFile == OrderedComments.end())
  return nullptr;

return &CommentsInFile->second;
335}

337bool RawCommentList::empty() const { return OrderedComments.empty(); }

339unsigned RawCommentList::getCommentBeginLine(RawComment *C, FileID File,
                                           unsigned Offset) const {
auto Cached = CommentBeginLine.find(C);
if (Cached != CommentBeginLine.end())
  return Cached->second;
const unsigned Line = SourceMgr.getLineNumber(File, Offset);
CommentBeginLine[C] = Line;
return Line;
347}

349unsigned RawCommentList::getCommentEndOffset(RawComment *C) const {
auto Cached = CommentEndOffset.find(C);
if (Cached != CommentEndOffset.end())
  return Cached->second;
const unsigned Offset =
    SourceMgr.getDecomposedLoc(C->getSourceRange().getEnd()).second;
CommentEndOffset[C] = Offset;
return Offset;
357}

359std::string RawComment::getFormattedText(const SourceManager &SourceMgr,
                                       DiagnosticsEngine &Diags) const {
llvm::StringRef CommentText = getRawText(SourceMgr);
if (CommentText.empty())
  return "";

llvm::BumpPtrAllocator Allocator;
// We do not parse any commands, so CommentOptions are ignored by
// comments::Lexer. Therefore, we just use default-constructed options.
CommentOptions DefOpts;
comments::CommandTraits EmptyTraits(Allocator, DefOpts);
comments::Lexer L(Allocator, Diags, EmptyTraits, getSourceRange().getBegin(),
                  CommentText.begin(), CommentText.end(),
                  /*ParseCommands=*/false);

std::string Result;
// A column number of the first non-whitespace token in the comment text.
// We skip whitespace up to this column, but keep the whitespace after this
// column. IndentColumn is calculated when lexing the first line and reused
// for the rest of lines.
unsigned IndentColumn = 0;

// Processes one line of the comment and adds it to the result.
// Handles skipping the indent at the start of the line.
// Returns false when eof is reached and true otherwise.
auto LexLine = [&](bool IsFirstLine) -> bool {
  comments::Token Tok;
  // Lex the first token on the line. We handle it separately, because we to
  // fix up its indentation.
  L.lex(Tok);
  if (Tok.is(comments::tok::eof))
    return false;
  if (Tok.is(comments::tok::newline)) {
    Result += "\n";
    return true;
  }
  llvm::StringRef TokText = L.getSpelling(Tok, SourceMgr);
  bool LocInvalid = false;
  unsigned TokColumn =
      SourceMgr.getSpellingColumnNumber(Tok.getLocation(), &LocInvalid);
  assert(!LocInvalid && "getFormattedText for invalid location")((void)0);

  // Amount of leading whitespace in TokText.
  size_t WhitespaceLen = TokText.find_first_not_of(" \t");
  if (WhitespaceLen == StringRef::npos)
    WhitespaceLen = TokText.size();
  // Remember the amount of whitespace we skipped in the first line to remove
  // indent up to that column in the following lines.
  if (IsFirstLine)
    IndentColumn = TokColumn + WhitespaceLen;

  // Amount of leading whitespace we actually want to skip.
  // For the first line we skip all the whitespace.
  // For the rest of the lines, we skip whitespace up to IndentColumn.
  unsigned SkipLen =
      IsFirstLine
          ? WhitespaceLen
          : std::min<size_t>(
                WhitespaceLen,
                std::max<int>(static_cast<int>(IndentColumn) - TokColumn, 0));
  llvm::StringRef Trimmed = TokText.drop_front(SkipLen);
  Result += Trimmed;
  // Lex all tokens in the rest of the line.
  for (L.lex(Tok); Tok.isNot(comments::tok::eof); L.lex(Tok)) {
    if (Tok.is(comments::tok::newline)) {
      Result += "\n";
      return true;
    }
    Result += L.getSpelling(Tok, SourceMgr);
  }
  // We've reached the end of file token.
  return false;
};

auto DropTrailingNewLines = [](std::string &Str) {
  while (!Str.empty() && Str.back() == '\n')
    Str.pop_back();
};

// Process first line separately to remember indent for the following lines.
if (!LexLine(/*IsFirstLine=*/true)) {
  DropTrailingNewLines(Result);
  return Result;
}
// Process the rest of the lines.
while (LexLine(/*IsFirstLine=*/false))
  ;
DropTrailingNewLines(Result);
return Result;
448}

←

/usr/src/gnu/usr.bin/clang/libclangAST/../../../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//===----------------------------------------------------------------------===//

17#ifndef LLVM_SUPPORT_ALLOCATOR_H
18#define LLVM_SUPPORT_ALLOCATOR_H

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>

37namespace llvm {

39namespace detail {

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,
                              size_t TotalMemory);

46} // end namespace detail

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,
        size_t SizeThreshold = SlabSize, size_t GrowthDelay = 128>
67class BumpPtrAllocatorImpl
  : public AllocatorBase<BumpPtrAllocatorImpl<AllocatorT, SlabSize,
                                              SizeThreshold, GrowthDelay>>,
    private AllocatorT {
71public:
static_assert(SizeThreshold <= SlabSize,
              "The SizeThreshold must be at most the SlabSize to ensure "
              "that objects larger than a slab go into their own memory "
              "allocation.");
static_assert(GrowthDelay > 0,
              "GrowthDelay must be at least 1 which already increases the"
              "slab size after each allocated slab.");

BumpPtrAllocatorImpl() = default;

template <typename T>
BumpPtrAllocatorImpl(T &&Allocator)
    : AllocatorT(std::forward<T &&>(Allocator)) {}

// Manually implement a move constructor as we must clear the old allocator's
// slabs as a matter of correctness.
BumpPtrAllocatorImpl(BumpPtrAllocatorImpl &&Old)
    : AllocatorT(static_cast<AllocatorT &&>(Old)), CurPtr(Old.CurPtr),
      End(Old.End), Slabs(std::move(Old.Slabs)),
      CustomSizedSlabs(std::move(Old.CustomSizedSlabs)),
      BytesAllocated(Old.BytesAllocated), RedZoneSize(Old.RedZoneSize) {
  Old.CurPtr = Old.End = nullptr;
  Old.BytesAllocated = 0;
  Old.Slabs.clear();
  Old.CustomSizedSlabs.clear();
}

~BumpPtrAllocatorImpl() {
  DeallocateSlabs(Slabs.begin(), Slabs.end());
  DeallocateCustomSizedSlabs();
}

BumpPtrAllocatorImpl &operator=(BumpPtrAllocatorImpl &&RHS) {
  DeallocateSlabs(Slabs.begin(), Slabs.end());
  DeallocateCustomSizedSlabs();

  CurPtr = RHS.CurPtr;
  End = RHS.End;
  BytesAllocated = RHS.BytesAllocated;
  RedZoneSize = RHS.RedZoneSize;
  Slabs = std::move(RHS.Slabs);
  CustomSizedSlabs = std::move(RHS.CustomSizedSlabs);
  AllocatorT::operator=(static_cast<AllocatorT &&>(RHS));

  RHS.CurPtr = RHS.End = nullptr;
  RHS.BytesAllocated = 0;
  RHS.Slabs.clear();
  RHS.CustomSizedSlabs.clear();
  return *this;
}

/// Deallocate all but the current slab and reset the current pointer
/// to the beginning of it, freeing all memory allocated so far.
void Reset() {
  // Deallocate all but the first slab, and deallocate all custom-sized slabs.
  DeallocateCustomSizedSlabs();
  CustomSizedSlabs.clear();

  if (Slabs.empty())
    return;

  // Reset the state.
  BytesAllocated = 0;
  CurPtr = (char *)Slabs.front();
  End = CurPtr + SlabSize;

  __asan_poison_memory_region(*Slabs.begin(), computeSlabSize(0));
  DeallocateSlabs(std::next(Slabs.begin()), Slabs.end());
  Slabs.erase(std::next(Slabs.begin()), Slabs.end());
}

/// Allocate space at the specified alignment.
LLVM_ATTRIBUTE_RETURNS_NONNULL__attribute__((returns_nonnull)) LLVM_ATTRIBUTE_RETURNS_NOALIAS__attribute__((__malloc__)) void *
Allocate(size_t Size, Align Alignment) {
  // Keep track of how many bytes we've allocated.
  BytesAllocated += Size;

  size_t Adjustment = offsetToAlignedAddr(CurPtr, Alignment);
7
←
Calling 'offsetToAlignedAddr'→
  assert(Adjustment + Size >= Size && "Adjustment + Size must not overflow")((void)0);

  size_t SizeToAllocate = Size;
153#if LLVM_ADDRESS_SANITIZER_BUILD0
  // Add trailing bytes as a "red zone" under ASan.
  SizeToAllocate += RedZoneSize;
156#endif

  // Check if we have enough space.
  if (Adjustment + SizeToAllocate <= size_t(End - CurPtr)) {
    char *AlignedPtr = CurPtr + Adjustment;
    CurPtr = AlignedPtr + SizeToAllocate;
    // Update the allocation point of this memory block in MemorySanitizer.
    // Without this, MemorySanitizer messages for values originated from here
    // will point to the allocation of the entire slab.
    __msan_allocated_memory(AlignedPtr, Size);
    // Similarly, tell ASan about this space.
    __asan_unpoison_memory_region(AlignedPtr, Size);
    return AlignedPtr;
  }

  // If Size is really big, allocate a separate slab for it.
  size_t PaddedSize = SizeToAllocate + Alignment.value() - 1;
  if (PaddedSize > SizeThreshold) {
    void *NewSlab =
        AllocatorT::Allocate(PaddedSize, alignof(std::max_align_t));
    // We own the new slab and don't want anyone reading anyting other than
    // pieces returned from this method.  So poison the whole slab.
    __asan_poison_memory_region(NewSlab, PaddedSize);
    CustomSizedSlabs.push_back(std::make_pair(NewSlab, PaddedSize));

    uintptr_t AlignedAddr = alignAddr(NewSlab, Alignment);
    assert(AlignedAddr + Size <= (uintptr_t)NewSlab + PaddedSize)((void)0);
    char *AlignedPtr = (char*)AlignedAddr;
    __msan_allocated_memory(AlignedPtr, Size);
    __asan_unpoison_memory_region(AlignedPtr, Size);
    return AlignedPtr;
  }

  // Otherwise, start a new slab and try again.
  StartNewSlab();
  uintptr_t AlignedAddr = alignAddr(CurPtr, Alignment);
  assert(AlignedAddr + SizeToAllocate <= (uintptr_t)End &&((void)0)
         "Unable to allocate memory!")((void)0);
  char *AlignedPtr = (char*)AlignedAddr;
  CurPtr = AlignedPtr + SizeToAllocate;
  __msan_allocated_memory(AlignedPtr, Size);
  __asan_unpoison_memory_region(AlignedPtr, Size);
  return AlignedPtr;
}

inline LLVM_ATTRIBUTE_RETURNS_NONNULL__attribute__((returns_nonnull)) LLVM_ATTRIBUTE_RETURNS_NOALIAS__attribute__((__malloc__)) void *
Allocate(size_t Size, size_t Alignment) {
  assert(Alignment > 0 && "0-byte alignment is not allowed. Use 1 instead.")((void)0);
  return Allocate(Size, Align(Alignment));
6
←
Calling 'BumpPtrAllocatorImpl::Allocate'→
}

// Pull in base class overloads.
using AllocatorBase<BumpPtrAllocatorImpl>::Allocate;

// Bump pointer allocators are expected to never free their storage; and
// clients expect pointers to remain valid for non-dereferencing uses even
// after deallocation.
void Deallocate(const void *Ptr, size_t Size, size_t /*Alignment*/) {
  __asan_poison_memory_region(Ptr, Size);
}

// Pull in base class overloads.
using AllocatorBase<BumpPtrAllocatorImpl>::Deallocate;

size_t GetNumSlabs() const { return Slabs.size() + CustomSizedSlabs.size(); }

/// \return An index uniquely and reproducibly identifying
/// an input pointer \p Ptr in the given allocator.
/// The returned value is negative iff the object is inside a custom-size
/// slab.
/// Returns an empty optional if the pointer is not found in the allocator.
llvm::Optional<int64_t> identifyObject(const void *Ptr) {
  const char *P = static_cast<const char *>(Ptr);
  int64_t InSlabIdx = 0;
  for (size_t Idx = 0, E = Slabs.size(); Idx < E; Idx++) {
    const char *S = static_cast<const char *>(Slabs[Idx]);
    if (P >= S && P < S + computeSlabSize(Idx))
      return InSlabIdx + static_cast<int64_t>(P - S);
    InSlabIdx += static_cast<int64_t>(computeSlabSize(Idx));
  }

  // Use negative index to denote custom sized slabs.
  int64_t InCustomSizedSlabIdx = -1;
  for (size_t Idx = 0, E = CustomSizedSlabs.size(); Idx < E; Idx++) {
    const char *S = static_cast<const char *>(CustomSizedSlabs[Idx].first);
    size_t Size = CustomSizedSlabs[Idx].second;
    if (P >= S && P < S + Size)
      return InCustomSizedSlabIdx - static_cast<int64_t>(P - S);
    InCustomSizedSlabIdx -= static_cast<int64_t>(Size);
  }
  return None;
}

/// A wrapper around identifyObject that additionally asserts that
/// the object is indeed within the allocator.
/// \return An index uniquely and reproducibly identifying
/// an input pointer \p Ptr in the given allocator.
int64_t identifyKnownObject(const void *Ptr) {
  Optional<int64_t> Out = identifyObject(Ptr);
  assert(Out && "Wrong allocator used")((void)0);
  return *Out;
}

/// A wrapper around identifyKnownObject. Accepts type information
/// about the object and produces a smaller identifier by relying on
/// the alignment information. Note that sub-classes may have different
/// alignment, so the most base class should be passed as template parameter
/// in order to obtain correct results. For that reason automatic template
/// parameter deduction is disabled.
/// \return An index uniquely and reproducibly identifying
/// an input pointer \p Ptr in the given allocator. This identifier is
/// different from the ones produced by identifyObject and
/// identifyAlignedObject.
template <typename T>
int64_t identifyKnownAlignedObject(const void *Ptr) {
  int64_t Out = identifyKnownObject(Ptr);
  assert(Out % alignof(T) == 0 && "Wrong alignment information")((void)0);
  return Out / alignof(T);
}

size_t getTotalMemory() const {
  size_t TotalMemory = 0;
  for (auto I = Slabs.begin(), E = Slabs.end(); I != E; ++I)
    TotalMemory += computeSlabSize(std::distance(Slabs.begin(), I));
  for (auto &PtrAndSize : CustomSizedSlabs)
    TotalMemory += PtrAndSize.second;
  return TotalMemory;
}

size_t getBytesAllocated() const { return BytesAllocated; }

void setRedZoneSize(size_t NewSize) {
  RedZoneSize = NewSize;
}

void PrintStats() const {
  detail::printBumpPtrAllocatorStats(Slabs.size(), BytesAllocated,
                                     getTotalMemory());
}

296private:
/// The current pointer into the current slab.
///
/// This points to the next free byte in the slab.
char *CurPtr = nullptr;

/// The end of the current slab.
char *End = nullptr;

/// The slabs allocated so far.
SmallVector<void *, 4> Slabs;

/// Custom-sized slabs allocated for too-large allocation requests.
SmallVector<std::pair<void *, size_t>, 0> CustomSizedSlabs;

/// How many bytes we've allocated.
///
/// Used so that we can compute how much space was wasted.
size_t BytesAllocated = 0;

/// The number of bytes to put between allocations when running under
/// a sanitizer.
size_t RedZoneSize = 1;

static size_t computeSlabSize(unsigned SlabIdx) {
  // Scale the actual allocated slab size based on the number of slabs
  // allocated. Every GrowthDelay slabs allocated, we double
  // the allocated size to reduce allocation frequency, but saturate at
  // multiplying the slab size by 2^30.
  return SlabSize *
         ((size_t)1 << std::min<size_t>(30, SlabIdx / GrowthDelay));
}

/// Allocate a new slab and move the bump pointers over into the new
/// slab, modifying CurPtr and End.
void StartNewSlab() {
  size_t AllocatedSlabSize = computeSlabSize(Slabs.size());

  void *NewSlab =
      AllocatorT::Allocate(AllocatedSlabSize, alignof(std::max_align_t));
  // We own the new slab and don't want anyone reading anything other than
  // pieces returned from this method.  So poison the whole slab.
  __asan_poison_memory_region(NewSlab, AllocatedSlabSize);

  Slabs.push_back(NewSlab);
  CurPtr = (char *)(NewSlab);
  End = ((char *)NewSlab) + AllocatedSlabSize;
}

/// Deallocate a sequence of slabs.
void DeallocateSlabs(SmallVectorImpl<void *>::iterator I,
                     SmallVectorImpl<void *>::iterator E) {
  for (; I != E; ++I) {
    size_t AllocatedSlabSize =
        computeSlabSize(std::distance(Slabs.begin(), I));
    AllocatorT::Deallocate(*I, AllocatedSlabSize, alignof(std::max_align_t));
  }
}

/// Deallocate all memory for custom sized slabs.
void DeallocateCustomSizedSlabs() {
  for (auto &PtrAndSize : CustomSizedSlabs) {
    void *Ptr = PtrAndSize.first;
    size_t Size = PtrAndSize.second;
    AllocatorT::Deallocate(Ptr, Size, alignof(std::max_align_t));
  }
}

template <typename T> friend class SpecificBumpPtrAllocator;
365};

367/// The standard BumpPtrAllocator which just uses the default template
368/// parameters.
369typedef BumpPtrAllocatorImpl<> BumpPtrAllocator;

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 {
BumpPtrAllocator Allocator;

379public:
SpecificBumpPtrAllocator() {
  // Because SpecificBumpPtrAllocator walks the memory to call destructors,
  // it can't have red zones between allocations.
  Allocator.setRedZoneSize(0);
}
SpecificBumpPtrAllocator(SpecificBumpPtrAllocator &&Old)
    : Allocator(std::move(Old.Allocator)) {}
~SpecificBumpPtrAllocator() { DestroyAll(); }

SpecificBumpPtrAllocator &operator=(SpecificBumpPtrAllocator &&RHS) {
  Allocator = std::move(RHS.Allocator);
  return *this;
}

/// Call the destructor of each allocated object and deallocate all but the
/// current slab and reset the current pointer to the beginning of it, freeing
/// all memory allocated so far.
void DestroyAll() {
  auto DestroyElements = [](char *Begin, char *End) {
    assert(Begin == (char *)alignAddr(Begin, Align::Of<T>()))((void)0);
    for (char *Ptr = Begin; Ptr + sizeof(T) <= End; Ptr += sizeof(T))
      reinterpret_cast<T *>(Ptr)->~T();
  };

  for (auto I = Allocator.Slabs.begin(), E = Allocator.Slabs.end(); I != E;
       ++I) {
    size_t AllocatedSlabSize = BumpPtrAllocator::computeSlabSize(
        std::distance(Allocator.Slabs.begin(), I));
    char *Begin = (char *)alignAddr(*I, Align::Of<T>());
    char *End = *I == Allocator.Slabs.back() ? Allocator.CurPtr
                                             : (char *)*I + AllocatedSlabSize;

    DestroyElements(Begin, End);
  }

  for (auto &PtrAndSize : Allocator.CustomSizedSlabs) {
    void *Ptr = PtrAndSize.first;
    size_t Size = PtrAndSize.second;
    DestroyElements((char *)alignAddr(Ptr, Align::Of<T>()),
                    (char *)Ptr + Size);
  }

  Allocator.Reset();
}

/// Allocate space for an array of objects without constructing them.
T *Allocate(size_t num = 1) { return Allocator.Allocate<T>(num); }
427};

429} // end namespace llvm

431template <typename AllocatorT, size_t SlabSize, size_t SizeThreshold,
        size_t GrowthDelay>
433void *
434operator new(size_t Size,
           llvm::BumpPtrAllocatorImpl<AllocatorT, SlabSize, SizeThreshold,
                                      GrowthDelay> &Allocator) {
return Allocator.Allocate(Size, std::min((size_t)llvm::NextPowerOf2(Size),
5
←
Calling 'BumpPtrAllocatorImpl::Allocate'→
                                         alignof(std::max_align_t)));
439}

441template <typename AllocatorT, size_t SlabSize, size_t SizeThreshold,
        size_t GrowthDelay>
443void operator delete(void *,
                   llvm::BumpPtrAllocatorImpl<AllocatorT, SlabSize,
                                              SizeThreshold, GrowthDelay> &) {
446}

448#endif // LLVM_SUPPORT_ALLOCATOR_H

←

/usr/src/gnu/usr.bin/clang/libclangAST/../../../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; }
12
←
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();
11
←
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;
9
←
The value 255 is assigned to 'A.ShiftValue'→
10
←
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);
8
←
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_