C++ SmallVectorImpl::insert方法代码示例

void DeclContext::localUncachedLookup(DeclarationName Name,
                                      SmallVectorImpl<NamedDecl *> &Results) {
  Results.clear();
  
  // If there's no external storage, just perform a normal lookup and copy
  // the results.
  if (!hasExternalVisibleStorage() && !hasExternalLexicalStorage() && Name) {
    lookup_result LookupResults = lookup(Name);
    Results.insert(Results.end(), LookupResults.begin(), LookupResults.end());
    return;
  }

  // If we have a lookup table, check there first. Maybe we'll get lucky.
  if (Name && !LookupPtr.getInt()) {
    if (StoredDeclsMap *Map = LookupPtr.getPointer()) {
      StoredDeclsMap::iterator Pos = Map->find(Name);
      if (Pos != Map->end()) {
        Results.insert(Results.end(),
                       Pos->second.getLookupResult().begin(),
                       Pos->second.getLookupResult().end());
        return;
      }
    }
  }

  // Slow case: grovel through the declarations in our chain looking for 
  // matches.
  for (Decl *D = FirstDecl; D; D = D->getNextDeclInContext()) {
    if (NamedDecl *ND = dyn_cast<NamedDecl>(D))
      if (ND->getDeclName() == Name)
        Results.push_back(ND);
  }
}

static void insertArgsFromProgramName(StringRef ProgName,
                                      const DriverSuffix *DS,
                                      SmallVectorImpl<const char *> &ArgVector,
                                      std::set<std::string> &SavedStrings) {
  if (!DS)
    return;

  if (const char *Flag = DS->ModeFlag) {
    // Add Flag to the arguments.
    auto it = ArgVector.begin();
    if (it != ArgVector.end())
      ++it;
    ArgVector.insert(it, Flag);
  }

  StringRef::size_type LastComponent = ProgName.rfind(
      '-', ProgName.size() - strlen(DS->Suffix));
  if (LastComponent == StringRef::npos)
    return;

  // Infer target from the prefix.
  StringRef Prefix = ProgName.slice(0, LastComponent);
  std::string IgnoredError;
  if (llvm::TargetRegistry::lookupTarget(Prefix, IgnoredError)) {
    auto it = ArgVector.begin();
    if (it != ArgVector.end())
      ++it;
    const char *arr[] = { "-target", GetStableCStr(SavedStrings, Prefix) };
    ArgVector.insert(it, std::begin(arr), std::end(arr));
  }
}

static void ParseProgName(SmallVectorImpl<const char *> &ArgVector,
                          std::set<std::string> &SavedStrings) {
  // Try to infer frontend type and default target from the program name by
  // comparing it against DriverSuffixes in order.

  // If there is a match, the function tries to identify a target as prefix.
  // E.g. "x86_64-linux-clang" as interpreted as suffix "clang" with target
  // prefix "x86_64-linux". If such a target prefix is found, is gets added via
  // -target as implicit first argument.

  std::string ProgName =llvm::sys::path::stem(ArgVector[0]);
#ifdef LLVM_ON_WIN32
  // Transform to lowercase for case insensitive file systems.
  ProgName = StringRef(ProgName).lower();
#endif

  StringRef ProgNameRef = ProgName;
  const DriverSuffix *DS = FindDriverSuffix(ProgNameRef);

  if (!DS) {
    // Try again after stripping any trailing version number:
    // clang++3.5 -> clang++
    ProgNameRef = ProgNameRef.rtrim("0123456789.");
    DS = FindDriverSuffix(ProgNameRef);
  }

  if (!DS) {
    // Try again after stripping trailing -component.
    // clang++-tot -> clang++
    ProgNameRef = ProgNameRef.slice(0, ProgNameRef.rfind('-'));
    DS = FindDriverSuffix(ProgNameRef);
  }

  if (DS) {
    if (const char *Flag = DS->ModeFlag) {
      // Add Flag to the arguments.
      auto it = ArgVector.begin();
      if (it != ArgVector.end())
        ++it;
      ArgVector.insert(it, Flag);
    }

    StringRef::size_type LastComponent = ProgNameRef.rfind(
        '-', ProgNameRef.size() - strlen(DS->Suffix));
    if (LastComponent == StringRef::npos)
      return;

    // Infer target from the prefix.
    StringRef Prefix = ProgNameRef.slice(0, LastComponent);
    std::string IgnoredError;
    if (llvm::TargetRegistry::lookupTarget(Prefix, IgnoredError)) {
      auto it = ArgVector.begin();
      if (it != ArgVector.end())
        ++it;
      const char *arr[] = { "-target", GetStableCStr(SavedStrings, Prefix) };
      ArgVector.insert(it, std::begin(arr), std::end(arr));
    }
  }
}

static void insertTargetAndModeArgs(StringRef Target, StringRef Mode,
                                    SmallVectorImpl<const char *> &ArgVector,
                                    std::set<std::string> &SavedStrings) {
  if (!Mode.empty()) {
    // Add the mode flag to the arguments.
    auto it = ArgVector.begin();
    if (it != ArgVector.end())
      ++it;
    ArgVector.insert(it, GetStableCStr(SavedStrings, Mode));
  }

  if (!Target.empty()) {
    auto it = ArgVector.begin();
    if (it != ArgVector.end())
      ++it;
    const char *arr[] = {"-target", GetStableCStr(SavedStrings, Target)};
    ArgVector.insert(it, std::begin(arr), std::end(arr));
  }
}

// Construct a DIE for this scope.
void DwarfCompileUnit::constructScopeDIE(
    LexicalScope *Scope, SmallVectorImpl<DIE *> &FinalChildren) {
  if (!Scope || !Scope->getScopeNode())
    return;

  auto *DS = Scope->getScopeNode();

  assert((Scope->getInlinedAt() || !isa<DISubprogram>(DS)) &&
         "Only handle inlined subprograms here, use "
         "constructSubprogramScopeDIE for non-inlined "
         "subprograms");

  SmallVector<DIE *, 8> Children;

  // We try to create the scope DIE first, then the children DIEs. This will
  // avoid creating un-used children then removing them later when we find out
  // the scope DIE is null.
  DIE *ScopeDIE;
  if (Scope->getParent() && isa<DISubprogram>(DS)) {
    ScopeDIE = constructInlinedScopeDIE(Scope);
    if (!ScopeDIE)
      return;
    // We create children when the scope DIE is not null.
    createScopeChildrenDIE(Scope, Children);
  } else {
    // Early exit when we know the scope DIE is going to be null.
    if (DD->isLexicalScopeDIENull(Scope))
      return;

    bool HasNonScopeChildren = false;

    // We create children here when we know the scope DIE is not going to be
    // null and the children will be added to the scope DIE.
    createScopeChildrenDIE(Scope, Children, &HasNonScopeChildren);

    // If there are only other scopes as children, put them directly in the
    // parent instead, as this scope would serve no purpose.
    if (!HasNonScopeChildren) {
      FinalChildren.insert(FinalChildren.end(),
                           std::make_move_iterator(Children.begin()),
                           std::make_move_iterator(Children.end()));
      return;
    }
    ScopeDIE = constructLexicalScopeDIE(Scope);
    assert(ScopeDIE && "Scope DIE should not be null.");
  }

  // Add children
  for (auto &I : Children)
    ScopeDIE->addChild(std::move(I));

  FinalChildren.push_back(std::move(ScopeDIE));
}

/// getNameWithPrefix - Fill OutName with the name of the appropriate prefix
/// and the specified global variable's name.  If the global variable doesn't
/// have a name, this fills in a unique name for the global.
void Mangler::getNameWithPrefix(SmallVectorImpl<char> &OutName,
                                const GlobalValue *GV) {
  ManglerPrefixTy PrefixTy = Mangler::Default;
  if (GV->hasPrivateLinkage())
    PrefixTy = Mangler::Private;
  else if (GV->hasLinkerPrivateLinkage() || GV->hasLinkerPrivateWeakLinkage())
    PrefixTy = Mangler::LinkerPrivate;
  
  // If this global has a name, handle it simply.
  if (GV->hasName()) {
    StringRef Name = GV->getName();
    getNameWithPrefix(OutName, Name, PrefixTy);
    // No need to do anything else if the global has the special "do not mangle"
    // flag in the name.
    if (Name[0] == 1)
      return;
  } else {
    // Get the ID for the global, assigning a new one if we haven't got one
    // already.
    unsigned &ID = AnonGlobalIDs[GV];
    if (ID == 0) ID = NextAnonGlobalID++;
  
    // Must mangle the global into a unique ID.
    getNameWithPrefix(OutName, "__unnamed_" + Twine(ID), PrefixTy);
  }

  // If we are supposed to add a microsoft-style suffix for stdcall/fastcall,
  // add it.
  if (DL->hasMicrosoftFastStdCallMangling()) {
    if (const Function *F = dyn_cast<Function>(GV)) {
      CallingConv::ID CC = F->getCallingConv();
    
      // fastcall functions need to start with @.
      // FIXME: This logic seems unlikely to be right.
      if (CC == CallingConv::X86_FastCall) {
        if (OutName[0] == '_')
          OutName[0] = '@';
        else
          OutName.insert(OutName.begin(), '@');
      }
    
      // fastcall and stdcall functions usually need @42 at the end to specify
      // the argument info.
      FunctionType *FT = F->getFunctionType();
      if ((CC == CallingConv::X86_FastCall || CC == CallingConv::X86_StdCall) &&
          // "Pure" variadic functions do not receive @0 suffix.
          (!FT->isVarArg() || FT->getNumParams() == 0 ||
           (FT->getNumParams() == 1 && F->hasStructRetAttr())))
        AddFastCallStdCallSuffix(OutName, F, *DL);
    }
  }
}

static void insertTargetAndModeArgs(const ParsedClangName &NameParts,
                                    SmallVectorImpl<const char *> &ArgVector,
                                    std::set<std::string> &SavedStrings) {
  // Put target and mode arguments at the start of argument list so that
  // arguments specified in command line could override them. Avoid putting
  // them at index 0, as an option like '-cc1' must remain the first.
  int InsertionPoint = 0;
  if (ArgVector.size() > 0)
    ++InsertionPoint;

  if (NameParts.DriverMode) {
    // Add the mode flag to the arguments.
    ArgVector.insert(ArgVector.begin() + InsertionPoint,
                     GetStableCStr(SavedStrings, NameParts.DriverMode));
  }

  if (NameParts.TargetIsValid) {
    const char *arr[] = {"-target", GetStableCStr(SavedStrings,
                                                  NameParts.TargetPrefix)};
    ArgVector.insert(ArgVector.begin() + InsertionPoint,
                     std::begin(arr), std::end(arr));
  }
}

// Include the debug info compression header:
// "ZLIB" followed by 8 bytes representing the uncompressed size of the section,
// useful for consumers to preallocate a buffer to decompress into.
static bool
prependCompressionHeader(uint64_t Size,
                         SmallVectorImpl<char> &CompressedContents) {
    const StringRef Magic = "ZLIB";
    if (Size <= Magic.size() + sizeof(Size) + CompressedContents.size())
        return false;
    if (sys::IsLittleEndianHost)
        sys::swapByteOrder(Size);
    CompressedContents.insert(CompressedContents.begin(),
                              Magic.size() + sizeof(Size), 0);
    std::copy(Magic.begin(), Magic.end(), CompressedContents.begin());
    std::copy(reinterpret_cast<char *>(&Size),
              reinterpret_cast<char *>(&Size + 1),
              CompressedContents.begin() + Magic.size());
    return true;
}

MipsInstrInfo::BranchType MipsInstrInfo::AnalyzeBranch(
    MachineBasicBlock &MBB, MachineBasicBlock *&TBB, MachineBasicBlock *&FBB,
    SmallVectorImpl<MachineOperand> &Cond, bool AllowModify,
    SmallVectorImpl<MachineInstr *> &BranchInstrs) const {

  MachineBasicBlock::reverse_iterator I = MBB.rbegin(), REnd = MBB.rend();

  // Skip all the debug instructions.
  while (I != REnd && I->isDebugValue())
    ++I;

  if (I == REnd || !isUnpredicatedTerminator(*I)) {
    // This block ends with no branches (it just falls through to its succ).
    // Leave TBB/FBB null.
    TBB = FBB = nullptr;
    return BT_NoBranch;
  }

  MachineInstr *LastInst = &*I;
  unsigned LastOpc = LastInst->getOpcode();
  BranchInstrs.push_back(LastInst);

  // Not an analyzable branch (e.g., indirect jump).
  if (!getAnalyzableBrOpc(LastOpc))
    return LastInst->isIndirectBranch() ? BT_Indirect : BT_None;

  // Get the second to last instruction in the block.
  unsigned SecondLastOpc = 0;
  MachineInstr *SecondLastInst = nullptr;

  if (++I != REnd) {
    SecondLastInst = &*I;
    SecondLastOpc = getAnalyzableBrOpc(SecondLastInst->getOpcode());

    // Not an analyzable branch (must be an indirect jump).
    if (isUnpredicatedTerminator(*SecondLastInst) && !SecondLastOpc)
      return BT_None;
  }

  // If there is only one terminator instruction, process it.
  if (!SecondLastOpc) {
    // Unconditional branch.
    if (LastInst->isUnconditionalBranch()) {
      TBB = LastInst->getOperand(0).getMBB();
      return BT_Uncond;
    }

    // Conditional branch
    AnalyzeCondBr(LastInst, LastOpc, TBB, Cond);
    return BT_Cond;
  }

  // If we reached here, there are two branches.
  // If there are three terminators, we don't know what sort of block this is.
  if (++I != REnd && isUnpredicatedTerminator(*I))
    return BT_None;

  BranchInstrs.insert(BranchInstrs.begin(), SecondLastInst);

  // If second to last instruction is an unconditional branch,
  // analyze it and remove the last instruction.
  if (SecondLastInst->isUnconditionalBranch()) {
    // Return if the last instruction cannot be removed.
    if (!AllowModify)
      return BT_None;

    TBB = SecondLastInst->getOperand(0).getMBB();
    LastInst->eraseFromParent();
    BranchInstrs.pop_back();
    return BT_Uncond;
  }

  // Conditional branch followed by an unconditional branch.
  // The last one must be unconditional.
  if (!LastInst->isUnconditionalBranch())
    return BT_None;

  AnalyzeCondBr(SecondLastInst, SecondLastOpc, TBB, Cond);
  FBB = LastInst->getOperand(0).getMBB();

  return BT_CondUncond;
}

static void ParseProgName(SmallVectorImpl<const char *> &ArgVector,
                          std::set<std::string> &SavedStrings,
                          Driver &TheDriver)
{
  // Try to infer frontend type and default target from the program name.

  // suffixes[] contains the list of known driver suffixes.
  // Suffixes are compared against the program name in order.
  // If there is a match, the frontend type is updated as necessary (CPP/C++).
  // If there is no match, a second round is done after stripping the last
  // hyphen and everything following it. This allows using something like
  // "clang++-2.9".

  // If there is a match in either the first or second round,
  // the function tries to identify a target as prefix. E.g.
  // "x86_64-linux-clang" as interpreted as suffix "clang" with
  // target prefix "x86_64-linux". If such a target prefix is found,
  // is gets added via -target as implicit first argument.
  static const struct {
    const char *Suffix;
    const char *ModeFlag;
  } suffixes [] = {
    { "templight",     nullptr },
    { "templight++",   "--driver-mode=g++" },
    { "templight-c++", "--driver-mode=g++" },
    { "templight-cc",  nullptr },
    { "templight-cpp", "--driver-mode=cpp" },
    { "templight-g++", "--driver-mode=g++" },
    { "templight-gcc", nullptr },
    { "templight-cl",  "--driver-mode=cl"  },
    { "cc",        nullptr },
    { "cpp",       "--driver-mode=cpp" },
    { "cl" ,       "--driver-mode=cl"  },
    { "++",        "--driver-mode=g++" },
  };
  std::string ProgName(llvm::sys::path::stem(ArgVector[0]));
#ifdef LLVM_ON_WIN32
  // Transform to lowercase for case insensitive file systems.
  std::transform(ProgName.begin(), ProgName.end(), ProgName.begin(),
                 toLowercase);
#endif
  StringRef ProgNameRef(ProgName);
  StringRef Prefix;

  for (int Components = 2; Components; --Components) {
    bool FoundMatch = false;
    size_t i;

    for (i = 0; i < sizeof(suffixes) / sizeof(suffixes[0]); ++i) {
      if (ProgNameRef.endswith(suffixes[i].Suffix)) {
        FoundMatch = true;
        SmallVectorImpl<const char *>::iterator it = ArgVector.begin();
        if (it != ArgVector.end())
          ++it;
        if (suffixes[i].ModeFlag)
          ArgVector.insert(it, suffixes[i].ModeFlag);
        break;
      }
    }

    if (FoundMatch) {
      StringRef::size_type LastComponent = ProgNameRef.rfind('-',
        ProgNameRef.size() - strlen(suffixes[i].Suffix));
      if (LastComponent != StringRef::npos)
        Prefix = ProgNameRef.slice(0, LastComponent);
      break;
    }

    StringRef::size_type LastComponent = ProgNameRef.rfind('-');
    if (LastComponent == StringRef::npos)
      break;
    ProgNameRef = ProgNameRef.slice(0, LastComponent);
  }

  if (Prefix.empty())
    return;

  std::string IgnoredError;
  if (llvm::TargetRegistry::lookupTarget(Prefix, IgnoredError)) {
    SmallVectorImpl<const char *>::iterator it = ArgVector.begin();
    if (it != ArgVector.end())
      ++it;
    const char* Strings[] =
      { GetStableCStr(SavedStrings, std::string("-target")),
        GetStableCStr(SavedStrings, Prefix) };
    ArgVector.insert(it, Strings, Strings + llvm::array_lengthof(Strings));
  }
}

/// GenerateNewArgTokens - Returns true if OldTokens can be converted to a new
/// vector of tokens in NewTokens.  The new number of arguments will be placed
/// in NumArgs and the ranges which need to surrounded in parentheses will be
/// in ParenHints.
/// Returns false if the token stream cannot be changed.  If this is because
/// of an initializer list starting a macro argument, the range of those
/// initializer lists will be place in InitLists.
static bool GenerateNewArgTokens(Preprocessor &PP,
                                 SmallVectorImpl<Token> &OldTokens,
                                 SmallVectorImpl<Token> &NewTokens,
                                 unsigned &NumArgs,
                                 SmallVectorImpl<SourceRange> &ParenHints,
                                 SmallVectorImpl<SourceRange> &InitLists) {
  if (!CheckMatchedBrackets(OldTokens))
    return false;

  // Once it is known that the brackets are matched, only a simple count of the
  // braces is needed.
  unsigned Braces = 0;

  // First token of a new macro argument.
  SmallVectorImpl<Token>::iterator ArgStartIterator = OldTokens.begin();

  // First closing brace in a new macro argument.  Used to generate
  // SourceRanges for InitLists.
  SmallVectorImpl<Token>::iterator ClosingBrace = OldTokens.end();
  NumArgs = 0;
  Token TempToken;
  // Set to true when a macro separator token is found inside a braced list.
  // If true, the fixed argument spans multiple old arguments and ParenHints
  // will be updated.
  bool FoundSeparatorToken = false;
  for (SmallVectorImpl<Token>::iterator I = OldTokens.begin(),
                                        E = OldTokens.end();
       I != E; ++I) {
    if (I->is(tok::l_brace)) {
      ++Braces;
    } else if (I->is(tok::r_brace)) {
      --Braces;
      if (Braces == 0 && ClosingBrace == E && FoundSeparatorToken)
        ClosingBrace = I;
    } else if (I->is(tok::eof)) {
      // EOF token is used to separate macro arguments
      if (Braces != 0) {
        // Assume comma separator is actually braced list separator and change
        // it back to a comma.
        FoundSeparatorToken = true;
        I->setKind(tok::comma);
        I->setLength(1);
      } else { // Braces == 0
        // Separator token still separates arguments.
        ++NumArgs;

        // If the argument starts with a brace, it can't be fixed with
        // parentheses.  A different diagnostic will be given.
        if (FoundSeparatorToken && ArgStartIterator->is(tok::l_brace)) {
          InitLists.push_back(
              SourceRange(ArgStartIterator->getLocation(),
                          PP.getLocForEndOfToken(ClosingBrace->getLocation())));
          ClosingBrace = E;
        }

        // Add left paren
        if (FoundSeparatorToken) {
          TempToken.startToken();
          TempToken.setKind(tok::l_paren);
          TempToken.setLocation(ArgStartIterator->getLocation());
          TempToken.setLength(0);
          NewTokens.push_back(TempToken);
        }

        // Copy over argument tokens
        NewTokens.insert(NewTokens.end(), ArgStartIterator, I);

        // Add right paren and store the paren locations in ParenHints
        if (FoundSeparatorToken) {
          SourceLocation Loc = PP.getLocForEndOfToken((I - 1)->getLocation());
          TempToken.startToken();
          TempToken.setKind(tok::r_paren);
          TempToken.setLocation(Loc);
          TempToken.setLength(0);
          NewTokens.push_back(TempToken);
          ParenHints.push_back(SourceRange(ArgStartIterator->getLocation(),
                                           Loc));
        }

        // Copy separator token
        NewTokens.push_back(*I);

        // Reset values
        ArgStartIterator = I + 1;
        FoundSeparatorToken = false;
      }
    }
  }

  return !ParenHints.empty() && InitLists.empty();
}