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llvm-project/clang/lib/Lex/Preprocessor.cpp
alexpaniman b9924c76da
[clang] Make -dump-tokens option align tokens (#164894) 
When using `-Xclang -dump-tokens`, the lexer dump output is currently
difficult to read because the data are misaligned. The existing
implementation simply separates the token name, spelling, flags, and
location using `'\t'`, which results in inconsistent spacing.

For example, the current output looks like this on provided in this
patch example **(BEFORE THIS PR)**:

<img width="2936" height="632" alt="image"
src="https://github.com/user-attachments/assets/ad893958-6d57-4a76-8838-7fc56e37e6a7"
/>

# Changes

This small PR improves the readability of the token dump by:

+ Adding padding after the token name and after the spelling (the
padding amount was chosen empirically to produce good average
alignment).
+ Swapping the order of location and flags (since flags can take up a
lot of space and disrupt alignment).

The result is a more readable output **(AFTER THIS PR)**:

<img width="1470" height="315" alt="image"
src="https://github.com/user-attachments/assets/c24f24e5-a431-42cc-b5b6-232bac5c635e"
/>
2026-04-03 08:33:36 -04:00

1880 lines
70 KiB
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//===- Preprocessor.cpp - C Language Family Preprocessor Implementation ---===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file implements the Preprocessor interface.
//
//===----------------------------------------------------------------------===//
//
// Options to support:
// -H - Print the name of each header file used.
// -d[DNI] - Dump various things.
// -fworking-directory - #line's with preprocessor's working dir.
// -fpreprocessed
// -dependency-file,-M,-MM,-MF,-MG,-MP,-MT,-MQ,-MD,-MMD
// -W*
// -w
//
// Messages to emit:
// "Multiple include guards may be useful for:\n"
//
//===----------------------------------------------------------------------===//
#include "clang/Lex/Preprocessor.h"
#include "clang/Basic/Builtins.h"
#include "clang/Basic/FileManager.h"
#include "clang/Basic/IdentifierTable.h"
#include "clang/Basic/LLVM.h"
#include "clang/Basic/LangOptions.h"
#include "clang/Basic/Module.h"
#include "clang/Basic/SourceLocation.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Basic/TargetInfo.h"
#include "clang/Lex/CodeCompletionHandler.h"
#include "clang/Lex/DependencyDirectivesScanner.h"
#include "clang/Lex/ExternalPreprocessorSource.h"
#include "clang/Lex/HeaderSearch.h"
#include "clang/Lex/LexDiagnostic.h"
#include "clang/Lex/Lexer.h"
#include "clang/Lex/LiteralSupport.h"
#include "clang/Lex/MacroArgs.h"
#include "clang/Lex/MacroInfo.h"
#include "clang/Lex/ModuleLoader.h"
#include "clang/Lex/NoTrivialPPDirectiveTracer.h"
#include "clang/Lex/Pragma.h"
#include "clang/Lex/PreprocessingRecord.h"
#include "clang/Lex/PreprocessorLexer.h"
#include "clang/Lex/PreprocessorOptions.h"
#include "clang/Lex/ScratchBuffer.h"
#include "clang/Lex/Token.h"
#include "clang/Lex/TokenLexer.h"
#include "llvm/ADT/APInt.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/ScopeExit.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/Capacity.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/FormatVariadic.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/MemoryBufferRef.h"
#include "llvm/Support/SaveAndRestore.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
#include <cassert>
#include <memory>
#include <optional>
#include <string>
#include <utility>
#include <vector>
using namespace clang;
/// Minimum distance between two check points, in tokens.
static constexpr unsigned CheckPointStepSize = 1024;
LLVM_INSTANTIATE_REGISTRY(PragmaHandlerRegistry)
ExternalPreprocessorSource::~ExternalPreprocessorSource() = default;
Preprocessor::Preprocessor(const PreprocessorOptions &PPOpts,
DiagnosticsEngine &diags, const LangOptions &opts,
SourceManager &SM, HeaderSearch &Headers,
ModuleLoader &TheModuleLoader,
IdentifierInfoLookup *IILookup, bool OwnsHeaders,
TranslationUnitKind TUKind)
: PPOpts(PPOpts), Diags(&diags), LangOpts(opts),
FileMgr(Headers.getFileMgr()), SourceMgr(SM),
ScratchBuf(new ScratchBuffer(SourceMgr)), HeaderInfo(Headers),
TheModuleLoader(TheModuleLoader), ExternalSource(nullptr),
// As the language options may have not been loaded yet (when
// deserializing an ASTUnit), adding keywords to the identifier table is
// deferred to Preprocessor::Initialize().
Identifiers(IILookup), PragmaHandlers(new PragmaNamespace(StringRef())),
TUKind(TUKind), SkipMainFilePreamble(0, true),
CurSubmoduleState(&NullSubmoduleState) {
OwnsHeaderSearch = OwnsHeaders;
// Default to discarding comments.
KeepComments = false;
KeepMacroComments = false;
SuppressIncludeNotFoundError = false;
// Macro expansion is enabled.
DisableMacroExpansion = false;
MacroExpansionInDirectivesOverride = false;
InMacroArgs = false;
ArgMacro = nullptr;
InMacroArgPreExpansion = false;
NumCachedTokenLexers = 0;
PragmasEnabled = true;
ParsingIfOrElifDirective = false;
PreprocessedOutput = false;
// We haven't read anything from the external source.
ReadMacrosFromExternalSource = false;
LastExportKeyword.startToken();
BuiltinInfo = std::make_unique<Builtin::Context>();
// "Poison" __VA_ARGS__, __VA_OPT__ which can only appear in the expansion of
// a macro. They get unpoisoned where it is allowed.
(Ident__VA_ARGS__ = getIdentifierInfo("__VA_ARGS__"))->setIsPoisoned();
SetPoisonReason(Ident__VA_ARGS__,diag::ext_pp_bad_vaargs_use);
(Ident__VA_OPT__ = getIdentifierInfo("__VA_OPT__"))->setIsPoisoned();
SetPoisonReason(Ident__VA_OPT__,diag::ext_pp_bad_vaopt_use);
// Initialize the pragma handlers.
RegisterBuiltinPragmas();
// Initialize builtin macros like __LINE__ and friends.
RegisterBuiltinMacros();
if(LangOpts.Borland) {
Ident__exception_info = getIdentifierInfo("_exception_info");
Ident___exception_info = getIdentifierInfo("__exception_info");
Ident_GetExceptionInfo = getIdentifierInfo("GetExceptionInformation");
Ident__exception_code = getIdentifierInfo("_exception_code");
Ident___exception_code = getIdentifierInfo("__exception_code");
Ident_GetExceptionCode = getIdentifierInfo("GetExceptionCode");
Ident__abnormal_termination = getIdentifierInfo("_abnormal_termination");
Ident___abnormal_termination = getIdentifierInfo("__abnormal_termination");
Ident_AbnormalTermination = getIdentifierInfo("AbnormalTermination");
} else {
Ident__exception_info = Ident__exception_code = nullptr;
Ident__abnormal_termination = Ident___exception_info = nullptr;
Ident___exception_code = Ident___abnormal_termination = nullptr;
Ident_GetExceptionInfo = Ident_GetExceptionCode = nullptr;
Ident_AbnormalTermination = nullptr;
}
// Default incremental processing to -fincremental-extensions, clients can
// override with `enableIncrementalProcessing` if desired.
IncrementalProcessing = LangOpts.IncrementalExtensions;
// If using a PCH where a #pragma hdrstop is expected, start skipping tokens.
if (usingPCHWithPragmaHdrStop())
SkippingUntilPragmaHdrStop = true;
// If using a PCH with a through header, start skipping tokens.
if (!this->PPOpts.PCHThroughHeader.empty() &&
!this->PPOpts.ImplicitPCHInclude.empty())
SkippingUntilPCHThroughHeader = true;
if (this->PPOpts.GeneratePreamble)
PreambleConditionalStack.startRecording();
MaxTokens = LangOpts.MaxTokens;
}
Preprocessor::~Preprocessor() {
assert(!isBacktrackEnabled() && "EnableBacktrack/Backtrack imbalance!");
IncludeMacroStack.clear();
// Free any cached macro expanders.
// This populates MacroArgCache, so all TokenLexers need to be destroyed
// before the code below that frees up the MacroArgCache list.
std::fill(TokenLexerCache, TokenLexerCache + NumCachedTokenLexers, nullptr);
CurTokenLexer.reset();
// Free any cached MacroArgs.
for (MacroArgs *ArgList = MacroArgCache; ArgList;)
ArgList = ArgList->deallocate();
// Delete the header search info, if we own it.
if (OwnsHeaderSearch)
delete &HeaderInfo;
}
void Preprocessor::Initialize(const TargetInfo &Target,
const TargetInfo *AuxTarget) {
assert((!this->Target || this->Target == &Target) &&
"Invalid override of target information");
this->Target = &Target;
assert((!this->AuxTarget || this->AuxTarget == AuxTarget) &&
"Invalid override of aux target information.");
this->AuxTarget = AuxTarget;
// Initialize information about built-ins.
BuiltinInfo->InitializeTarget(Target, AuxTarget);
HeaderInfo.setTarget(Target);
// Populate the identifier table with info about keywords for the current language.
Identifiers.AddKeywords(LangOpts);
// Initialize the __FTL_EVAL_METHOD__ macro to the TargetInfo.
setTUFPEvalMethod(getTargetInfo().getFPEvalMethod());
if (getLangOpts().getFPEvalMethod() == LangOptions::FEM_UnsetOnCommandLine)
// Use setting from TargetInfo.
setCurrentFPEvalMethod(SourceLocation(), Target.getFPEvalMethod());
else
// Set initial value of __FLT_EVAL_METHOD__ from the command line.
setCurrentFPEvalMethod(SourceLocation(), getLangOpts().getFPEvalMethod());
}
void Preprocessor::InitializeForModelFile() {
NumEnteredSourceFiles = 0;
// Reset pragmas
PragmaHandlersBackup = std::move(PragmaHandlers);
PragmaHandlers = std::make_unique<PragmaNamespace>(StringRef());
RegisterBuiltinPragmas();
// Reset PredefinesFileID
PredefinesFileID = FileID();
}
void Preprocessor::FinalizeForModelFile() {
NumEnteredSourceFiles = 1;
PragmaHandlers = std::move(PragmaHandlersBackup);
}
void Preprocessor::DumpToken(const Token &Tok, bool DumpFlags) const {
std::string TokenStr;
llvm::raw_string_ostream OS(TokenStr);
// The alignment of 16 is chosen to comfortably fit most identifiers.
OS << llvm::formatv("{0,-16} ", tok::getTokenName(Tok.getKind()));
// Annotation tokens are just markers that don't have a spelling -- they
// indicate where something expanded.
if (!Tok.isAnnotation()) {
OS << "'";
// Escape string to prevent token spelling from spanning multiple lines.
OS.write_escaped(getSpelling(Tok));
OS << "'";
}
// The alignment of 48 (32 characters for the spelling + the 16 for
// the identifier name) fits most variable names, keywords and annotations.
llvm::errs() << llvm::formatv("{0,-48} ", OS.str());
if (!DumpFlags) return;
auto Loc = Tok.getLocation();
llvm::errs() << "Loc=<";
DumpLocation(Loc);
llvm::errs() << ">";
// If the token points directly to a file location (i.e. not a macro
// expansion), then add additional padding so that trailing markers
// align, provided the line/column numbers are reasonably sized.
//
// Otherwise, if it's a macro expansion, don't bother with alignment,
// as the line will include multiple locations and be very long.
//
// NOTE: To keep this stateless, it doesn't account for filename
// length, so when a header starts markers will be temporarily misaligned.
if (Loc.isFileID()) {
PresumedLoc PLoc = SourceMgr.getPresumedLoc(Loc);
if (!PLoc.isInvalid()) {
int LineWidth = llvm::utostr(PLoc.getLine()).size();
int ColumnWidth = llvm::utostr(PLoc.getColumn()).size();
// Reserve space for lines up to 9999 and columns up to 99,
// which is 4 + 2 = 6 characters in total.
const int ReservedSpace = 6;
int LeftSpace = ReservedSpace - LineWidth - ColumnWidth;
int Padding = std::max<int>(0, LeftSpace);
llvm::errs().indent(Padding);
}
}
if (Tok.isAtStartOfLine())
llvm::errs() << " [StartOfLine]";
if (Tok.hasLeadingSpace())
llvm::errs() << " [LeadingSpace]";
if (Tok.isExpandDisabled())
llvm::errs() << " [ExpandDisabled]";
if (Tok.needsCleaning()) {
const char *Start = SourceMgr.getCharacterData(Tok.getLocation());
llvm::errs() << " [UnClean='" << StringRef(Start, Tok.getLength()) << "']";
}
}
void Preprocessor::DumpLocation(SourceLocation Loc) const {
Loc.print(llvm::errs(), SourceMgr);
}
void Preprocessor::DumpMacro(const MacroInfo &MI) const {
llvm::errs() << "MACRO: ";
for (unsigned i = 0, e = MI.getNumTokens(); i != e; ++i) {
DumpToken(MI.getReplacementToken(i));
llvm::errs() << " ";
}
llvm::errs() << "\n";
}
void Preprocessor::PrintStats() {
llvm::errs() << "\n*** Preprocessor Stats:\n";
llvm::errs() << NumDirectives << " directives found:\n";
llvm::errs() << " " << NumDefined << " #define.\n";
llvm::errs() << " " << NumUndefined << " #undef.\n";
llvm::errs() << " #include/#include_next/#import:\n";
llvm::errs() << " " << NumEnteredSourceFiles << " source files entered.\n";
llvm::errs() << " " << MaxIncludeStackDepth << " max include stack depth\n";
llvm::errs() << " " << NumIf << " #if/#ifndef/#ifdef.\n";
llvm::errs() << " " << NumElse << " #else/#elif/#elifdef/#elifndef.\n";
llvm::errs() << " " << NumEndif << " #endif.\n";
llvm::errs() << " " << NumPragma << " #pragma.\n";
llvm::errs() << NumSkipped << " #if/#ifndef#ifdef regions skipped\n";
llvm::errs() << NumMacroExpanded << "/" << NumFnMacroExpanded << "/"
<< NumBuiltinMacroExpanded << " obj/fn/builtin macros expanded, "
<< NumFastMacroExpanded << " on the fast path.\n";
llvm::errs() << (NumFastTokenPaste+NumTokenPaste)
<< " token paste (##) operations performed, "
<< NumFastTokenPaste << " on the fast path.\n";
llvm::errs() << "\nPreprocessor Memory: " << getTotalMemory() << "B total";
llvm::errs() << "\n BumpPtr: " << BP.getTotalMemory();
llvm::errs() << "\n Macro Expanded Tokens: "
<< llvm::capacity_in_bytes(MacroExpandedTokens);
llvm::errs() << "\n Predefines Buffer: " << Predefines.capacity();
// FIXME: List information for all submodules.
llvm::errs() << "\n Macros: "
<< llvm::capacity_in_bytes(CurSubmoduleState->Macros);
llvm::errs() << "\n #pragma push_macro Info: "
<< llvm::capacity_in_bytes(PragmaPushMacroInfo);
llvm::errs() << "\n Poison Reasons: "
<< llvm::capacity_in_bytes(PoisonReasons);
llvm::errs() << "\n Comment Handlers: "
<< llvm::capacity_in_bytes(CommentHandlers) << "\n";
}
Preprocessor::macro_iterator
Preprocessor::macro_begin(bool IncludeExternalMacros) const {
if (IncludeExternalMacros && ExternalSource &&
!ReadMacrosFromExternalSource) {
ReadMacrosFromExternalSource = true;
ExternalSource->ReadDefinedMacros();
}
// Make sure we cover all macros in visible modules.
for (const ModuleMacro &Macro : ModuleMacros)
CurSubmoduleState->Macros.try_emplace(Macro.II);
return CurSubmoduleState->Macros.begin();
}
size_t Preprocessor::getTotalMemory() const {
return BP.getTotalMemory()
+ llvm::capacity_in_bytes(MacroExpandedTokens)
+ Predefines.capacity() /* Predefines buffer. */
// FIXME: Include sizes from all submodules, and include MacroInfo sizes,
// and ModuleMacros.
+ llvm::capacity_in_bytes(CurSubmoduleState->Macros)
+ llvm::capacity_in_bytes(PragmaPushMacroInfo)
+ llvm::capacity_in_bytes(PoisonReasons)
+ llvm::capacity_in_bytes(CommentHandlers);
}
Preprocessor::macro_iterator
Preprocessor::macro_end(bool IncludeExternalMacros) const {
if (IncludeExternalMacros && ExternalSource &&
!ReadMacrosFromExternalSource) {
ReadMacrosFromExternalSource = true;
ExternalSource->ReadDefinedMacros();
}
return CurSubmoduleState->Macros.end();
}
/// Compares macro tokens with a specified token value sequence.
static bool MacroDefinitionEquals(const MacroInfo *MI,
ArrayRef<TokenValue> Tokens) {
return Tokens.size() == MI->getNumTokens() &&
std::equal(Tokens.begin(), Tokens.end(), MI->tokens_begin());
}
StringRef Preprocessor::getLastMacroWithSpelling(
SourceLocation Loc,
ArrayRef<TokenValue> Tokens) const {
SourceLocation BestLocation;
StringRef BestSpelling;
for (Preprocessor::macro_iterator I = macro_begin(), E = macro_end();
I != E; ++I) {
const MacroDirective::DefInfo
Def = I->second.findDirectiveAtLoc(Loc, SourceMgr);
if (!Def || !Def.getMacroInfo())
continue;
if (!Def.getMacroInfo()->isObjectLike())
continue;
if (!MacroDefinitionEquals(Def.getMacroInfo(), Tokens))
continue;
SourceLocation Location = Def.getLocation();
// Choose the macro defined latest.
if (BestLocation.isInvalid() ||
(Location.isValid() &&
SourceMgr.isBeforeInTranslationUnit(BestLocation, Location))) {
BestLocation = Location;
BestSpelling = I->first->getName();
}
}
return BestSpelling;
}
void Preprocessor::recomputeCurLexerKind() {
if (CurLexer)
CurLexerCallback = CurLexer->isDependencyDirectivesLexer()
? CLK_DependencyDirectivesLexer
: CLK_Lexer;
else if (CurTokenLexer)
CurLexerCallback = CLK_TokenLexer;
else
CurLexerCallback = CLK_CachingLexer;
}
bool Preprocessor::SetCodeCompletionPoint(FileEntryRef File,
unsigned CompleteLine,
unsigned CompleteColumn) {
assert(CompleteLine && CompleteColumn && "Starts from 1:1");
assert(!CodeCompletionFile && "Already set");
// Load the actual file's contents.
std::optional<llvm::MemoryBufferRef> Buffer =
SourceMgr.getMemoryBufferForFileOrNone(File);
if (!Buffer)
return true;
// Find the byte position of the truncation point.
const char *Position = Buffer->getBufferStart();
for (unsigned Line = 1; Line < CompleteLine; ++Line) {
for (; *Position; ++Position) {
if (*Position != '\r' && *Position != '\n')
continue;
// Eat \r\n or \n\r as a single line.
if ((Position[1] == '\r' || Position[1] == '\n') &&
Position[0] != Position[1])
++Position;
++Position;
break;
}
}
Position += CompleteColumn - 1;
// If pointing inside the preamble, adjust the position at the beginning of
// the file after the preamble.
if (SkipMainFilePreamble.first &&
SourceMgr.getFileEntryForID(SourceMgr.getMainFileID()) == File) {
if (Position - Buffer->getBufferStart() < SkipMainFilePreamble.first)
Position = Buffer->getBufferStart() + SkipMainFilePreamble.first;
}
if (Position > Buffer->getBufferEnd())
Position = Buffer->getBufferEnd();
CodeCompletionFile = File;
CodeCompletionOffset = Position - Buffer->getBufferStart();
auto NewBuffer = llvm::WritableMemoryBuffer::getNewUninitMemBuffer(
Buffer->getBufferSize() + 1, Buffer->getBufferIdentifier());
char *NewBuf = NewBuffer->getBufferStart();
char *NewPos = std::copy(Buffer->getBufferStart(), Position, NewBuf);
*NewPos = '\0';
std::copy(Position, Buffer->getBufferEnd(), NewPos+1);
SourceMgr.overrideFileContents(File, std::move(NewBuffer));
return false;
}
void Preprocessor::CodeCompleteIncludedFile(llvm::StringRef Dir,
bool IsAngled) {
setCodeCompletionReached();
if (CodeComplete)
CodeComplete->CodeCompleteIncludedFile(Dir, IsAngled);
}
void Preprocessor::CodeCompleteNaturalLanguage() {
setCodeCompletionReached();
if (CodeComplete)
CodeComplete->CodeCompleteNaturalLanguage();
}
/// getSpelling - This method is used to get the spelling of a token into a
/// SmallVector. Note that the returned StringRef may not point to the
/// supplied buffer if a copy can be avoided.
StringRef Preprocessor::getSpelling(const Token &Tok,
SmallVectorImpl<char> &Buffer,
bool *Invalid) const {
// NOTE: this has to be checked *before* testing for an IdentifierInfo.
if (Tok.isNot(tok::raw_identifier) && !Tok.hasUCN()) {
// Try the fast path.
if (const IdentifierInfo *II = Tok.getIdentifierInfo())
return II->getName();
}
// Resize the buffer if we need to copy into it.
if (Tok.needsCleaning())
Buffer.resize(Tok.getLength());
const char *Ptr = Buffer.data();
unsigned Len = getSpelling(Tok, Ptr, Invalid);
return StringRef(Ptr, Len);
}
/// CreateString - Plop the specified string into a scratch buffer and return a
/// location for it. If specified, the source location provides a source
/// location for the token.
void Preprocessor::CreateString(StringRef Str, Token &Tok,
SourceLocation ExpansionLocStart,
SourceLocation ExpansionLocEnd) {
Tok.setLength(Str.size());
const char *DestPtr;
SourceLocation Loc = ScratchBuf->getToken(Str.data(), Str.size(), DestPtr);
if (ExpansionLocStart.isValid())
Loc = SourceMgr.createExpansionLoc(Loc, ExpansionLocStart,
ExpansionLocEnd, Str.size());
Tok.setLocation(Loc);
// If this is a raw identifier or a literal token, set the pointer data.
if (Tok.is(tok::raw_identifier))
Tok.setRawIdentifierData(DestPtr);
else if (Tok.isLiteral())
Tok.setLiteralData(DestPtr);
}
SourceLocation Preprocessor::SplitToken(SourceLocation Loc, unsigned Length) {
auto &SM = getSourceManager();
SourceLocation SpellingLoc = SM.getSpellingLoc(Loc);
FileIDAndOffset LocInfo = SM.getDecomposedLoc(SpellingLoc);
bool Invalid = false;
StringRef Buffer = SM.getBufferData(LocInfo.first, &Invalid);
if (Invalid)
return SourceLocation();
// FIXME: We could consider re-using spelling for tokens we see repeatedly.
const char *DestPtr;
SourceLocation Spelling =
ScratchBuf->getToken(Buffer.data() + LocInfo.second, Length, DestPtr);
return SM.createTokenSplitLoc(Spelling, Loc, Loc.getLocWithOffset(Length));
}
Module *Preprocessor::getCurrentModule() {
if (!getLangOpts().isCompilingModule())
return nullptr;
return getHeaderSearchInfo().lookupModule(getLangOpts().CurrentModule);
}
Module *Preprocessor::getCurrentModuleImplementation() {
if (!getLangOpts().isCompilingModuleImplementation())
return nullptr;
return getHeaderSearchInfo().lookupModule(getLangOpts().ModuleName);
}
//===----------------------------------------------------------------------===//
// Preprocessor Initialization Methods
//===----------------------------------------------------------------------===//
/// EnterMainSourceFile - Enter the specified FileID as the main source file,
/// which implicitly adds the builtin defines etc.
void Preprocessor::EnterMainSourceFile() {
// We do not allow the preprocessor to reenter the main file. Doing so will
// cause FileID's to accumulate information from both runs (e.g. #line
// information) and predefined macros aren't guaranteed to be set properly.
assert(NumEnteredSourceFiles == 0 && "Cannot reenter the main file!");
FileID MainFileID = SourceMgr.getMainFileID();
// If MainFileID is loaded it means we loaded an AST file, no need to enter
// a main file.
if (!SourceMgr.isLoadedFileID(MainFileID)) {
// Enter the main file source buffer.
EnterSourceFile(MainFileID, nullptr, SourceLocation());
// If we've been asked to skip bytes in the main file (e.g., as part of a
// precompiled preamble), do so now.
if (SkipMainFilePreamble.first > 0)
CurLexer->SetByteOffset(SkipMainFilePreamble.first,
SkipMainFilePreamble.second);
// Tell the header info that the main file was entered. If the file is later
// #imported, it won't be re-entered.
if (OptionalFileEntryRef FE = SourceMgr.getFileEntryRefForID(MainFileID))
markIncluded(*FE);
// Record the first PP token in the main file. This is used to generate
// better diagnostics for C++ modules.
//
// // This is a comment.
// #define FOO int // note: add 'module;' to the start of the file
// ^ FirstPPToken // to introduce a global module fragment.
//
// export module M; // error: module declaration must occur
// // at the start of the translation unit.
if (getLangOpts().CPlusPlusModules) {
std::optional<StringRef> Input =
getSourceManager().getBufferDataOrNone(MainFileID);
if (!isPreprocessedModuleFile() && Input)
MainFileIsPreprocessedModuleFile =
clang::isPreprocessedModuleFile(*Input);
auto Tracer = std::make_unique<NoTrivialPPDirectiveTracer>(*this);
DirTracer = Tracer.get();
addPPCallbacks(std::move(Tracer));
std::optional<Token> FirstPPTok = CurLexer->peekNextPPToken();
if (FirstPPTok)
FirstPPTokenLoc = FirstPPTok->getLocation();
}
}
// Preprocess Predefines to populate the initial preprocessor state.
std::unique_ptr<llvm::MemoryBuffer> SB =
llvm::MemoryBuffer::getMemBufferCopy(Predefines, "<built-in>");
assert(SB && "Cannot create predefined source buffer");
FileID FID = SourceMgr.createFileID(std::move(SB));
assert(FID.isValid() && "Could not create FileID for predefines?");
setPredefinesFileID(FID);
// Start parsing the predefines.
EnterSourceFile(FID, nullptr, SourceLocation());
if (!PPOpts.PCHThroughHeader.empty()) {
// Lookup and save the FileID for the through header. If it isn't found
// in the search path, it's a fatal error.
OptionalFileEntryRef File = LookupFile(
SourceLocation(), PPOpts.PCHThroughHeader,
/*isAngled=*/false, /*FromDir=*/nullptr, /*FromFile=*/nullptr,
/*CurDir=*/nullptr, /*SearchPath=*/nullptr, /*RelativePath=*/nullptr,
/*SuggestedModule=*/nullptr, /*IsMapped=*/nullptr,
/*IsFrameworkFound=*/nullptr);
if (!File) {
Diag(SourceLocation(), diag::err_pp_through_header_not_found)
<< PPOpts.PCHThroughHeader;
return;
}
setPCHThroughHeaderFileID(
SourceMgr.createFileID(*File, SourceLocation(), SrcMgr::C_User));
}
// Skip tokens from the Predefines and if needed the main file.
if ((usingPCHWithThroughHeader() && SkippingUntilPCHThroughHeader) ||
(usingPCHWithPragmaHdrStop() && SkippingUntilPragmaHdrStop))
SkipTokensWhileUsingPCH();
}
void Preprocessor::setPCHThroughHeaderFileID(FileID FID) {
assert(PCHThroughHeaderFileID.isInvalid() &&
"PCHThroughHeaderFileID already set!");
PCHThroughHeaderFileID = FID;
}
bool Preprocessor::isPCHThroughHeader(const FileEntry *FE) {
assert(PCHThroughHeaderFileID.isValid() &&
"Invalid PCH through header FileID");
return FE == SourceMgr.getFileEntryForID(PCHThroughHeaderFileID);
}
bool Preprocessor::creatingPCHWithThroughHeader() {
return TUKind == TU_Prefix && !PPOpts.PCHThroughHeader.empty() &&
PCHThroughHeaderFileID.isValid();
}
bool Preprocessor::usingPCHWithThroughHeader() {
return TUKind != TU_Prefix && !PPOpts.PCHThroughHeader.empty() &&
PCHThroughHeaderFileID.isValid();
}
bool Preprocessor::creatingPCHWithPragmaHdrStop() {
return TUKind == TU_Prefix && PPOpts.PCHWithHdrStop;
}
bool Preprocessor::usingPCHWithPragmaHdrStop() {
return TUKind != TU_Prefix && PPOpts.PCHWithHdrStop;
}
/// Skip tokens until after the #include of the through header or
/// until after a #pragma hdrstop is seen. Tokens in the predefines file
/// and the main file may be skipped. If the end of the predefines file
/// is reached, skipping continues into the main file. If the end of the
/// main file is reached, it's a fatal error.
void Preprocessor::SkipTokensWhileUsingPCH() {
bool ReachedMainFileEOF = false;
bool UsingPCHThroughHeader = SkippingUntilPCHThroughHeader;
bool UsingPragmaHdrStop = SkippingUntilPragmaHdrStop;
Token Tok;
while (true) {
bool InPredefines =
(CurLexer && CurLexer->getFileID() == getPredefinesFileID());
CurLexerCallback(*this, Tok);
if (Tok.is(tok::eof) && !InPredefines) {
ReachedMainFileEOF = true;
break;
}
if (UsingPCHThroughHeader && !SkippingUntilPCHThroughHeader)
break;
if (UsingPragmaHdrStop && !SkippingUntilPragmaHdrStop)
break;
}
if (ReachedMainFileEOF) {
if (UsingPCHThroughHeader)
Diag(SourceLocation(), diag::err_pp_through_header_not_seen)
<< PPOpts.PCHThroughHeader << 1;
else if (!PPOpts.PCHWithHdrStopCreate)
Diag(SourceLocation(), diag::err_pp_pragma_hdrstop_not_seen);
}
}
void Preprocessor::replayPreambleConditionalStack() {
// Restore the conditional stack from the preamble, if there is one.
if (PreambleConditionalStack.isReplaying()) {
assert(CurPPLexer &&
"CurPPLexer is null when calling replayPreambleConditionalStack.");
CurPPLexer->setConditionalLevels(PreambleConditionalStack.getStack());
PreambleConditionalStack.doneReplaying();
if (PreambleConditionalStack.reachedEOFWhileSkipping())
SkipExcludedConditionalBlock(
PreambleConditionalStack.SkipInfo->HashTokenLoc,
PreambleConditionalStack.SkipInfo->IfTokenLoc,
PreambleConditionalStack.SkipInfo->FoundNonSkipPortion,
PreambleConditionalStack.SkipInfo->FoundElse,
PreambleConditionalStack.SkipInfo->ElseLoc);
}
}
void Preprocessor::EndSourceFile() {
// Notify the client that we reached the end of the source file.
if (Callbacks)
Callbacks->EndOfMainFile();
}
//===----------------------------------------------------------------------===//
// Lexer Event Handling.
//===----------------------------------------------------------------------===//
/// LookUpIdentifierInfo - Given a tok::raw_identifier token, look up the
/// identifier information for the token and install it into the token,
/// updating the token kind accordingly.
IdentifierInfo *Preprocessor::LookUpIdentifierInfo(Token &Identifier) const {
assert(!Identifier.getRawIdentifier().empty() && "No raw identifier data!");
// Look up this token, see if it is a macro, or if it is a language keyword.
IdentifierInfo *II;
if (!Identifier.needsCleaning() && !Identifier.hasUCN()) {
// No cleaning needed, just use the characters from the lexed buffer.
II = getIdentifierInfo(Identifier.getRawIdentifier());
} else {
// Cleaning needed, alloca a buffer, clean into it, then use the buffer.
SmallString<64> IdentifierBuffer;
StringRef CleanedStr = getSpelling(Identifier, IdentifierBuffer);
if (Identifier.hasUCN()) {
SmallString<64> UCNIdentifierBuffer;
expandUCNs(UCNIdentifierBuffer, CleanedStr);
II = getIdentifierInfo(UCNIdentifierBuffer);
} else {
II = getIdentifierInfo(CleanedStr);
}
}
// Update the token info (identifier info and appropriate token kind).
// FIXME: the raw_identifier may contain leading whitespace which is removed
// from the cleaned identifier token. The SourceLocation should be updated to
// refer to the non-whitespace character. For instance, the text "\\\nB" (a
// line continuation before 'B') is parsed as a single tok::raw_identifier and
// is cleaned to tok::identifier "B". After cleaning the token's length is
// still 3 and the SourceLocation refers to the location of the backslash.
Identifier.setIdentifierInfo(II);
Identifier.setKind(II->getTokenID());
return II;
}
void Preprocessor::SetPoisonReason(IdentifierInfo *II, unsigned DiagID) {
PoisonReasons[II] = DiagID;
}
void Preprocessor::PoisonSEHIdentifiers(bool Poison) {
assert(Ident__exception_code && Ident__exception_info);
assert(Ident___exception_code && Ident___exception_info);
Ident__exception_code->setIsPoisoned(Poison);
Ident___exception_code->setIsPoisoned(Poison);
Ident_GetExceptionCode->setIsPoisoned(Poison);
Ident__exception_info->setIsPoisoned(Poison);
Ident___exception_info->setIsPoisoned(Poison);
Ident_GetExceptionInfo->setIsPoisoned(Poison);
Ident__abnormal_termination->setIsPoisoned(Poison);
Ident___abnormal_termination->setIsPoisoned(Poison);
Ident_AbnormalTermination->setIsPoisoned(Poison);
}
void Preprocessor::HandlePoisonedIdentifier(Token & Identifier) {
assert(Identifier.getIdentifierInfo() &&
"Can't handle identifiers without identifier info!");
llvm::DenseMap<IdentifierInfo*,unsigned>::const_iterator it =
PoisonReasons.find(Identifier.getIdentifierInfo());
if(it == PoisonReasons.end())
Diag(Identifier, diag::err_pp_used_poisoned_id);
else
Diag(Identifier,it->second) << Identifier.getIdentifierInfo();
}
void Preprocessor::updateOutOfDateIdentifier(const IdentifierInfo &II) const {
assert(II.isOutOfDate() && "not out of date");
assert(getExternalSource() &&
"getExternalSource() should not return nullptr");
getExternalSource()->updateOutOfDateIdentifier(II);
}
/// HandleIdentifier - This callback is invoked when the lexer reads an
/// identifier. This callback looks up the identifier in the map and/or
/// potentially macro expands it or turns it into a named token (like 'for').
///
/// Note that callers of this method are guarded by checking the
/// IdentifierInfo's 'isHandleIdentifierCase' bit. If this method changes, the
/// IdentifierInfo methods that compute these properties will need to change to
/// match.
bool Preprocessor::HandleIdentifier(Token &Identifier) {
assert(Identifier.getIdentifierInfo() &&
"Can't handle identifiers without identifier info!");
IdentifierInfo &II = *Identifier.getIdentifierInfo();
// If the information about this identifier is out of date, update it from
// the external source.
// We have to treat __VA_ARGS__ in a special way, since it gets
// serialized with isPoisoned = true, but our preprocessor may have
// unpoisoned it if we're defining a C99 macro.
if (II.isOutOfDate()) {
bool CurrentIsPoisoned = false;
const bool IsSpecialVariadicMacro =
&II == Ident__VA_ARGS__ || &II == Ident__VA_OPT__;
if (IsSpecialVariadicMacro)
CurrentIsPoisoned = II.isPoisoned();
updateOutOfDateIdentifier(II);
Identifier.setKind(II.getTokenID());
if (IsSpecialVariadicMacro)
II.setIsPoisoned(CurrentIsPoisoned);
}
// If this identifier was poisoned, and if it was not produced from a macro
// expansion, emit an error.
if (II.isPoisoned() && CurPPLexer) {
HandlePoisonedIdentifier(Identifier);
}
// If this is a macro to be expanded, do it.
if (const MacroDefinition MD = getMacroDefinition(&II)) {
const auto *MI = MD.getMacroInfo();
assert(MI && "macro definition with no macro info?");
if (!DisableMacroExpansion) {
if (!Identifier.isExpandDisabled() && MI->isEnabled()) {
// C99 6.10.3p10: If the preprocessing token immediately after the
// macro name isn't a '(', this macro should not be expanded.
if (!MI->isFunctionLike() || isNextPPTokenOneOf(tok::l_paren))
return HandleMacroExpandedIdentifier(Identifier, MD);
} else {
// C99 6.10.3.4p2 says that a disabled macro may never again be
// expanded, even if it's in a context where it could be expanded in the
// future.
Identifier.setFlag(Token::DisableExpand);
if (MI->isObjectLike() || isNextPPTokenOneOf(tok::l_paren))
Diag(Identifier, diag::pp_disabled_macro_expansion);
}
}
}
// If this identifier is a keyword in a newer Standard or proposed Standard,
// produce a warning. Don't warn if we're not considering macro expansion,
// since this identifier might be the name of a macro.
// FIXME: This warning is disabled in cases where it shouldn't be, like
// "#define constexpr constexpr", "int constexpr;"
if (II.isFutureCompatKeyword() && !DisableMacroExpansion) {
Diag(Identifier, getIdentifierTable().getFutureCompatDiagKind(II, getLangOpts()))
<< II.getName();
// Don't diagnose this keyword again in this translation unit.
II.setIsFutureCompatKeyword(false);
}
// If this identifier would be a keyword in C++, diagnose as a compatibility
// issue.
if (II.IsKeywordInCPlusPlus() && !DisableMacroExpansion)
Diag(Identifier, diag::warn_pp_identifier_is_cpp_keyword) << &II;
// If this is an extension token, diagnose its use.
// We avoid diagnosing tokens that originate from macro definitions.
// FIXME: This warning is disabled in cases where it shouldn't be,
// like "#define TY typeof", "TY(1) x".
if (II.isExtensionToken() && !DisableMacroExpansion)
Diag(Identifier, diag::ext_token_used);
// Handle module contextual keywords.
if (getLangOpts().CPlusPlusModules && CurLexer &&
!CurLexer->isLexingRawMode() && !CurLexer->isPragmaLexer() &&
!CurLexer->ParsingPreprocessorDirective &&
Identifier.isModuleContextualKeyword() &&
HandleModuleContextualKeyword(Identifier)) {
HandleDirective(Identifier);
// With a fatal failure in the module loader, we abort parsing.
return hadModuleLoaderFatalFailure();
}
// If this is the 'import' contextual keyword following an '@', note
// that the next token indicates a module name.
//
// Note that we do not treat 'import' as a contextual
// keyword when we're in a caching lexer, because caching lexers only get
// used in contexts where import declarations are disallowed.
//
// Likewise if this is the standard C++ import keyword.
if (((LastTokenWasAt && II.isImportKeyword()) ||
Identifier.is(tok::kw_import)) &&
!InMacroArgs &&
(!DisableMacroExpansion || MacroExpansionInDirectivesOverride) &&
CurLexerCallback != CLK_CachingLexer) {
ModuleImportLoc = Identifier.getLocation();
IsAtImport = true;
CurLexerCallback = CLK_LexAfterModuleImport;
}
return true;
}
void Preprocessor::Lex(Token &Result) {
++LexLevel;
// We loop here until a lex function returns a token; this avoids recursion.
while (!CurLexerCallback(*this, Result))
;
if (Result.is(tok::unknown) && TheModuleLoader.HadFatalFailure)
return;
if (Result.is(tok::code_completion) && Result.getIdentifierInfo()) {
// Remember the identifier before code completion token.
setCodeCompletionIdentifierInfo(Result.getIdentifierInfo());
setCodeCompletionTokenRange(Result.getLocation(), Result.getEndLoc());
// Set IdenfitierInfo to null to avoid confusing code that handles both
// identifiers and completion tokens.
Result.setIdentifierInfo(nullptr);
}
// Update StdCXXImportSeqState to track our position within a C++20 import-seq
// if this token is being produced as a result of phase 4 of translation.
// Update TrackGMFState to decide if we are currently in a Global Module
// Fragment. GMF state updates should precede StdCXXImportSeq ones, since GMF state
// depends on the prevailing StdCXXImportSeq state in two cases.
if (getLangOpts().CPlusPlusModules && LexLevel == 1 &&
!Result.getFlag(Token::IsReinjected)) {
switch (Result.getKind()) {
case tok::l_paren: case tok::l_square: case tok::l_brace:
StdCXXImportSeqState.handleOpenBracket();
break;
case tok::r_paren: case tok::r_square:
StdCXXImportSeqState.handleCloseBracket();
break;
case tok::r_brace:
StdCXXImportSeqState.handleCloseBrace();
break;
#define PRAGMA_ANNOTATION(X) case tok::annot_##X:
// For `#pragma ...` mimic ';'.
#include "clang/Basic/TokenKinds.def"
#undef PRAGMA_ANNOTATION
// This token is injected to represent the translation of '#include "a.h"'
// into "import a.h;". Mimic the notional ';'.
case tok::annot_module_include:
case tok::annot_repl_input_end:
case tok::semi:
TrackGMFState.handleSemi();
StdCXXImportSeqState.handleSemi();
ModuleDeclState.handleSemi();
break;
case tok::header_name:
case tok::annot_header_unit:
StdCXXImportSeqState.handleHeaderName();
break;
case tok::kw_export:
if (hasSeenNoTrivialPPDirective())
Result.setFlag(Token::HasSeenNoTrivialPPDirective);
TrackGMFState.handleExport();
StdCXXImportSeqState.handleExport();
ModuleDeclState.handleExport();
break;
case tok::colon:
ModuleDeclState.handleColon();
break;
case tok::kw_import:
if (StdCXXImportSeqState.atTopLevel()) {
TrackGMFState.handleImport(StdCXXImportSeqState.afterTopLevelSeq());
StdCXXImportSeqState.handleImport();
}
break;
case tok::kw_module:
if (StdCXXImportSeqState.atTopLevel()) {
if (hasSeenNoTrivialPPDirective())
Result.setFlag(Token::HasSeenNoTrivialPPDirective);
TrackGMFState.handleModule(StdCXXImportSeqState.afterTopLevelSeq());
ModuleDeclState.handleModule();
}
break;
case tok::annot_module_name:
ModuleDeclState.handleModuleName(
static_cast<ModuleNameLoc *>(Result.getAnnotationValue()));
if (ModuleDeclState.isModuleCandidate())
break;
[[fallthrough]];
default:
TrackGMFState.handleMisc();
StdCXXImportSeqState.handleMisc();
ModuleDeclState.handleMisc();
break;
}
}
if (CurLexer && ++CheckPointCounter == CheckPointStepSize) {
CheckPoints[CurLexer->getFileID()].push_back(CurLexer->BufferPtr);
CheckPointCounter = 0;
}
LastTokenWasAt = Result.is(tok::at);
if (Result.isNot(tok::kw_export))
LastExportKeyword.startToken();
--LexLevel;
// Destroy any lexers that were deferred while we were in nested Lex calls.
// This must happen after decrementing LexLevel but before any other
// processing that might re-enter Lex.
if (LexLevel == 0 && !PendingDestroyLexers.empty())
PendingDestroyLexers.clear();
if ((LexLevel == 0 || PreprocessToken) &&
!Result.getFlag(Token::IsReinjected)) {
if (LexLevel == 0)
++TokenCount;
if (OnToken)
OnToken(Result);
}
}
void Preprocessor::LexTokensUntilEOF(std::vector<Token> *Tokens) {
while (1) {
Token Tok;
Lex(Tok);
if (Tok.isOneOf(tok::unknown, tok::eof, tok::eod,
tok::annot_repl_input_end))
break;
if (Tokens != nullptr)
Tokens->push_back(Tok);
}
}
/// Lex a header-name token (including one formed from header-name-tokens if
/// \p AllowMacroExpansion is \c true).
///
/// \param FilenameTok Filled in with the next token. On success, this will
/// be either a header_name token. On failure, it will be whatever other
/// token was found instead.
/// \param AllowMacroExpansion If \c true, allow the header name to be formed
/// by macro expansion (concatenating tokens as necessary if the first
/// token is a '<').
/// \return \c true if we reached EOD or EOF while looking for a > token in
/// a concatenated header name and diagnosed it. \c false otherwise.
bool Preprocessor::LexHeaderName(Token &FilenameTok, bool AllowMacroExpansion) {
// Lex using header-name tokenization rules if tokens are being lexed from
// a file. Just grab a token normally if we're in a macro expansion.
if (CurPPLexer) {
// Avoid nested header-name lexing when macro expansion recurses
// __has_include(__has_include))
if (CurPPLexer->ParsingFilename)
LexUnexpandedToken(FilenameTok);
else
CurPPLexer->LexIncludeFilename(FilenameTok);
} else {
Lex(FilenameTok);
}
// This could be a <foo/bar.h> file coming from a macro expansion. In this
// case, glue the tokens together into an angle_string_literal token.
SmallString<128> FilenameBuffer;
if (FilenameTok.is(tok::less) && AllowMacroExpansion) {
bool StartOfLine = FilenameTok.isAtStartOfLine();
bool LeadingSpace = FilenameTok.hasLeadingSpace();
bool LeadingEmptyMacro = FilenameTok.hasLeadingEmptyMacro();
SourceLocation Start = FilenameTok.getLocation();
SourceLocation End;
FilenameBuffer.push_back('<');
// Consume tokens until we find a '>'.
// FIXME: A header-name could be formed starting or ending with an
// alternative token. It's not clear whether that's ill-formed in all
// cases.
while (FilenameTok.isNot(tok::greater)) {
Lex(FilenameTok);
if (FilenameTok.isOneOf(tok::eod, tok::eof)) {
Diag(FilenameTok.getLocation(), diag::err_expected) << tok::greater;
Diag(Start, diag::note_matching) << tok::less;
return true;
}
End = FilenameTok.getLocation();
// FIXME: Provide code completion for #includes.
if (FilenameTok.is(tok::code_completion)) {
setCodeCompletionReached();
Lex(FilenameTok);
continue;
}
// Append the spelling of this token to the buffer. If there was a space
// before it, add it now.
if (FilenameTok.hasLeadingSpace())
FilenameBuffer.push_back(' ');
// Get the spelling of the token, directly into FilenameBuffer if
// possible.
size_t PreAppendSize = FilenameBuffer.size();
FilenameBuffer.resize(PreAppendSize + FilenameTok.getLength());
const char *BufPtr = &FilenameBuffer[PreAppendSize];
unsigned ActualLen = getSpelling(FilenameTok, BufPtr);
// If the token was spelled somewhere else, copy it into FilenameBuffer.
if (BufPtr != &FilenameBuffer[PreAppendSize])
memcpy(&FilenameBuffer[PreAppendSize], BufPtr, ActualLen);
// Resize FilenameBuffer to the correct size.
if (FilenameTok.getLength() != ActualLen)
FilenameBuffer.resize(PreAppendSize + ActualLen);
}
FilenameTok.startToken();
FilenameTok.setKind(tok::header_name);
FilenameTok.setFlagValue(Token::StartOfLine, StartOfLine);
FilenameTok.setFlagValue(Token::LeadingSpace, LeadingSpace);
FilenameTok.setFlagValue(Token::LeadingEmptyMacro, LeadingEmptyMacro);
CreateString(FilenameBuffer, FilenameTok, Start, End);
} else if (FilenameTok.is(tok::string_literal) && AllowMacroExpansion) {
// Convert a string-literal token of the form " h-char-sequence "
// (produced by macro expansion) into a header-name token.
//
// The rules for header-names don't quite match the rules for
// string-literals, but all the places where they differ result in
// undefined behavior, so we can and do treat them the same.
//
// A string-literal with a prefix or suffix is not translated into a
// header-name. This could theoretically be observable via the C++20
// context-sensitive header-name formation rules.
StringRef Str = getSpelling(FilenameTok, FilenameBuffer);
if (Str.size() >= 2 && Str.front() == '"' && Str.back() == '"')
FilenameTok.setKind(tok::header_name);
}
return false;
}
std::optional<Token> Preprocessor::peekNextPPToken() const {
// Do some quick tests for rejection cases.
std::optional<Token> Val;
if (CurLexer)
Val = CurLexer->peekNextPPToken();
else
Val = CurTokenLexer->peekNextPPToken();
if (!Val) {
// We have run off the end. If it's a source file we don't
// examine enclosing ones (C99 5.1.1.2p4). Otherwise walk up the
// macro stack.
if (CurPPLexer)
return std::nullopt;
for (const IncludeStackInfo &Entry : llvm::reverse(IncludeMacroStack)) {
if (Entry.TheLexer)
Val = Entry.TheLexer->peekNextPPToken();
else
Val = Entry.TheTokenLexer->peekNextPPToken();
if (Val)
break;
// Ran off the end of a source file?
if (Entry.ThePPLexer)
return std::nullopt;
}
}
// Okay, we found the token and return. Otherwise we found the end of the
// translation unit.
return Val;
}
// We represent the primary and partition names as 'Paths' which are sections
// of the hierarchical access path for a clang module. However for C++20
// the periods in a name are just another character, and we will need to
// flatten them into a string.
std::string ModuleLoader::getFlatNameFromPath(ModuleIdPath Path) {
std::string Name;
if (Path.empty())
return Name;
for (auto &Piece : Path) {
assert(Piece.getIdentifierInfo() && Piece.getLoc().isValid());
if (!Name.empty())
Name += ".";
Name += Piece.getIdentifierInfo()->getName();
}
return Name;
}
ModuleNameLoc *ModuleNameLoc::Create(Preprocessor &PP, ModuleIdPath Path) {
assert(!Path.empty() && "expect at least one identifier in a module name");
void *Mem = PP.getPreprocessorAllocator().Allocate(
totalSizeToAlloc<IdentifierLoc>(Path.size()), alignof(ModuleNameLoc));
return new (Mem) ModuleNameLoc(Path);
}
bool Preprocessor::LexModuleNameContinue(Token &Tok, SourceLocation UseLoc,
SmallVectorImpl<Token> &Suffix,
SmallVectorImpl<IdentifierLoc> &Path,
bool AllowMacroExpansion,
bool IsPartition) {
auto ConsumeToken = [&]() {
if (AllowMacroExpansion)
Lex(Tok);
else
LexUnexpandedToken(Tok);
Suffix.push_back(Tok);
};
while (true) {
if (Tok.isNot(tok::identifier)) {
if (Tok.is(tok::code_completion)) {
CurLexer->cutOffLexing();
CodeComplete->CodeCompleteModuleImport(UseLoc, Path);
return true;
}
Diag(Tok, diag::err_pp_module_expected_ident) << Path.empty();
return true;
}
// [cpp.pre]/p2:
// No identifier in the pp-module-name or pp-module-partition shall
// currently be defined as an object-like macro.
if (MacroInfo *MI = getMacroInfo(Tok.getIdentifierInfo());
MI && MI->isObjectLike() && getLangOpts().CPlusPlus20 &&
!AllowMacroExpansion) {
Diag(Tok, diag::err_pp_module_name_is_macro)
<< IsPartition << Tok.getIdentifierInfo();
Diag(MI->getDefinitionLoc(), diag::note_macro_here)
<< Tok.getIdentifierInfo();
}
// Record this part of the module path.
Path.emplace_back(Tok.getLocation(), Tok.getIdentifierInfo());
ConsumeToken();
if (Tok.isNot(tok::period))
return false;
ConsumeToken();
}
}
bool Preprocessor::HandleModuleName(StringRef DirType, SourceLocation UseLoc,
Token &Tok,
SmallVectorImpl<IdentifierLoc> &Path,
SmallVectorImpl<Token> &DirToks,
bool AllowMacroExpansion,
bool IsPartition) {
bool LeadingSpace = Tok.hasLeadingSpace();
unsigned NumToksInDirective = DirToks.size();
if (LexModuleNameContinue(Tok, UseLoc, DirToks, Path, AllowMacroExpansion,
IsPartition)) {
if (Tok.isNot(tok::eod))
CheckEndOfDirective(DirType,
/*EnableMacros=*/false, &DirToks);
EnterModuleSuffixTokenStream(DirToks);
return true;
}
// Clean the module-name tokens and replace these tokens with
// annot_module_name.
DirToks.resize(NumToksInDirective);
ModuleNameLoc *NameLoc = ModuleNameLoc::Create(*this, Path);
DirToks.emplace_back();
DirToks.back().setKind(tok::annot_module_name);
DirToks.back().setAnnotationRange(NameLoc->getRange());
DirToks.back().setAnnotationValue(static_cast<void *>(NameLoc));
DirToks.back().setFlagValue(Token::LeadingSpace, LeadingSpace);
DirToks.push_back(Tok);
return false;
}
/// [cpp.pre]/p2:
/// A preprocessing directive consists of a sequence of preprocessing tokens
/// that satisfies the following constraints: At the start of translation phase
/// 4, the first preprocessing token in the sequence, referred to as a
/// directive-introducing token, begins with the first character in the source
/// file (optionally after whitespace containing no new-line characters) or
/// follows whitespace containing at least one new-line character, and is:
/// - a # preprocessing token, or
/// - an import preprocessing token immediately followed on the same logical
/// source line by a header-name, <, identifier, or : preprocessing token, or
/// - a module preprocessing token immediately followed on the same logical
/// source line by an identifier, :, or ; preprocessing token, or
/// - an export preprocessing token immediately followed on the same logical
/// source line by one of the two preceding forms.
///
///
/// At the start of phase 4 an import or module token is treated as starting a
/// directive and are converted to their respective keywords iff:
/// - After skipping horizontal whitespace are
/// - at the start of a logical line, or
/// - preceded by an 'export' at the start of the logical line.
/// - Are followed by an identifier pp token (before macro expansion), or
/// - <, ", or : (but not ::) pp tokens for 'import', or
/// - ; for 'module'
/// Otherwise the token is treated as an identifier.
bool Preprocessor::HandleModuleContextualKeyword(Token &Result) {
if (!getLangOpts().CPlusPlusModules || !Result.isModuleContextualKeyword())
return false;
if (Result.is(tok::kw_export)) {
LastExportKeyword = Result;
return false;
}
/// Trait 'module' and 'import' as a identifier when the main file is a
/// preprocessed module file. We only allow '__preprocessed_module' and
/// '__preprocessed_import' in this context.
IdentifierInfo *II = Result.getIdentifierInfo();
if (isPreprocessedModuleFile() &&
(II->isStr(tok::getKeywordSpelling(tok::kw_import)) ||
II->isStr(tok::getKeywordSpelling(tok::kw_module))))
return false;
if (LastExportKeyword.is(tok::kw_export)) {
// The export keyword was not at the start of line, it's not a
// directive-introducing token.
if (!LastExportKeyword.isAtPhysicalStartOfLine())
return false;
// [cpp.pre]/1.4
// export // not a preprocessing directive
// import foo; // preprocessing directive (ill-formed at phase7)
if (Result.isAtPhysicalStartOfLine())
return false;
} else if (!Result.isAtPhysicalStartOfLine())
return false;
llvm::SaveAndRestore<bool> SavedParsingPreprocessorDirective(
CurPPLexer->ParsingPreprocessorDirective, true);
// The next token may be an angled string literal after import keyword.
llvm::SaveAndRestore<bool> SavedParsingFilemame(
CurPPLexer->ParsingFilename,
Result.getIdentifierInfo()->isImportKeyword());
std::optional<Token> NextTok =
CurLexer ? CurLexer->peekNextPPToken() : CurTokenLexer->peekNextPPToken();
if (!NextTok)
return false;
if (NextTok->is(tok::raw_identifier))
LookUpIdentifierInfo(*NextTok);
if (Result.getIdentifierInfo()->isImportKeyword()) {
if (NextTok->isOneOf(tok::identifier, tok::less, tok::colon,
tok::header_name)) {
Result.setKind(tok::kw_import);
ModuleImportLoc = Result.getLocation();
IsAtImport = false;
return true;
}
}
if (Result.getIdentifierInfo()->isModuleKeyword() &&
NextTok->isOneOf(tok::identifier, tok::colon, tok::semi)) {
Result.setKind(tok::kw_module);
ModuleDeclLoc = Result.getLocation();
return true;
}
// Ok, it's an identifier.
return false;
}
bool Preprocessor::CollectPPImportSuffixAndEnterStream(
SmallVectorImpl<Token> &Toks, bool StopUntilEOD) {
CollectPPImportSuffix(Toks);
EnterModuleSuffixTokenStream(Toks);
return false;
}
/// Collect the tokens of a C++20 pp-import-suffix.
void Preprocessor::CollectPPImportSuffix(SmallVectorImpl<Token> &Toks,
bool StopUntilEOD) {
while (true) {
Toks.emplace_back();
Lex(Toks.back());
switch (Toks.back().getKind()) {
case tok::semi:
if (!StopUntilEOD)
return;
[[fallthrough]];
case tok::eod:
case tok::eof:
return;
default:
break;
}
}
}
// Allocate a holding buffer for a sequence of tokens and introduce it into
// the token stream.
void Preprocessor::EnterModuleSuffixTokenStream(ArrayRef<Token> Toks) {
if (Toks.empty())
return;
auto ToksCopy = std::make_unique<Token[]>(Toks.size());
std::copy(Toks.begin(), Toks.end(), ToksCopy.get());
EnterTokenStream(std::move(ToksCopy), Toks.size(),
/*DisableMacroExpansion*/ false, /*IsReinject*/ false);
assert(CurTokenLexer && "Must have a TokenLexer");
CurTokenLexer->setLexingCXXModuleDirective();
}
/// Lex a token following the 'import' contextual keyword.
///
/// pp-import: [C++20]
/// import header-name pp-import-suffix[opt] ;
/// import header-name-tokens pp-import-suffix[opt] ;
/// [ObjC] @ import module-name ;
/// [Clang] import module-name ;
///
/// header-name-tokens:
/// string-literal
/// < [any sequence of preprocessing-tokens other than >] >
///
/// module-name:
/// module-name-qualifier[opt] identifier
///
/// module-name-qualifier
/// module-name-qualifier[opt] identifier .
///
/// We respond to a pp-import by importing macros from the named module.
bool Preprocessor::LexAfterModuleImport(Token &Result) {
// Figure out what kind of lexer we actually have.
recomputeCurLexerKind();
SmallVector<Token, 32> Suffix;
SmallVector<IdentifierLoc, 3> Path;
Lex(Result);
if (LexModuleNameContinue(Result, ModuleImportLoc, Suffix, Path,
/*AllowMacroExpansion=*/true,
/*IsPartition=*/false))
return CollectPPImportSuffixAndEnterStream(Suffix);
ModuleNameLoc *NameLoc = ModuleNameLoc::Create(*this, Path);
Suffix.clear();
Suffix.emplace_back();
Suffix.back().setKind(tok::annot_module_name);
Suffix.back().setAnnotationRange(NameLoc->getRange());
Suffix.back().setAnnotationValue(static_cast<void *>(NameLoc));
Suffix.push_back(Result);
// Consume the pp-import-suffix and expand any macros in it now, if we're not
// at the semicolon already.
SourceLocation SemiLoc = Result.getLocation();
if (Suffix.back().isNot(tok::semi)) {
if (Suffix.back().isNot(tok::eof))
CollectPPImportSuffix(Suffix);
if (Suffix.back().isNot(tok::semi)) {
// This is not an import after all.
EnterModuleSuffixTokenStream(Suffix);
return false;
}
SemiLoc = Suffix.back().getLocation();
}
Module *Imported = nullptr;
if (getLangOpts().Modules) {
Imported = TheModuleLoader.loadModule(ModuleImportLoc, Path, Module::Hidden,
/*IsInclusionDirective=*/false);
if (Imported)
makeModuleVisible(Imported, SemiLoc);
}
if (Callbacks)
Callbacks->moduleImport(ModuleImportLoc, Path, Imported);
if (!Suffix.empty()) {
EnterModuleSuffixTokenStream(Suffix);
return false;
}
return true;
}
void Preprocessor::makeModuleVisible(Module *M, SourceLocation Loc,
bool IncludeExports) {
CurSubmoduleState->VisibleModules.setVisible(
M, Loc, IncludeExports, [](Module *) {},
[&](ArrayRef<Module *> Path, Module *Conflict, StringRef Message) {
// FIXME: Include the path in the diagnostic.
// FIXME: Include the import location for the conflicting module.
Diag(ModuleImportLoc, diag::warn_module_conflict)
<< Path[0]->getFullModuleName()
<< Conflict->getFullModuleName()
<< Message;
});
// Add this module to the imports list of the currently-built submodule.
if (!BuildingSubmoduleStack.empty() && M != BuildingSubmoduleStack.back().M)
BuildingSubmoduleStack.back().M->Imports.insert(M);
}
bool Preprocessor::FinishLexStringLiteral(Token &Result, std::string &String,
const char *DiagnosticTag,
bool AllowMacroExpansion) {
// We need at least one string literal.
if (Result.isNot(tok::string_literal)) {
Diag(Result, diag::err_expected_string_literal)
<< /*Source='in...'*/0 << DiagnosticTag;
return false;
}
// Lex string literal tokens, optionally with macro expansion.
SmallVector<Token, 4> StrToks;
do {
StrToks.push_back(Result);
if (Result.hasUDSuffix())
Diag(Result, diag::err_invalid_string_udl);
if (AllowMacroExpansion)
Lex(Result);
else
LexUnexpandedToken(Result);
} while (Result.is(tok::string_literal));
// Concatenate and parse the strings.
StringLiteralParser Literal(StrToks, *this);
assert(Literal.isOrdinary() && "Didn't allow wide strings in");
if (Literal.hadError)
return false;
if (Literal.Pascal) {
Diag(StrToks[0].getLocation(), diag::err_expected_string_literal)
<< /*Source='in...'*/0 << DiagnosticTag;
return false;
}
String = std::string(Literal.GetString());
return true;
}
bool Preprocessor::parseSimpleIntegerLiteral(Token &Tok, uint64_t &Value) {
assert(Tok.is(tok::numeric_constant));
SmallString<8> IntegerBuffer;
bool NumberInvalid = false;
StringRef Spelling = getSpelling(Tok, IntegerBuffer, &NumberInvalid);
if (NumberInvalid)
return false;
NumericLiteralParser Literal(Spelling, Tok.getLocation(), getSourceManager(),
getLangOpts(), getTargetInfo(),
getDiagnostics());
if (Literal.hadError || !Literal.isIntegerLiteral() || Literal.hasUDSuffix())
return false;
llvm::APInt APVal(64, 0);
if (Literal.GetIntegerValue(APVal))
return false;
Lex(Tok);
Value = APVal.getLimitedValue();
return true;
}
void Preprocessor::addCommentHandler(CommentHandler *Handler) {
assert(Handler && "NULL comment handler");
assert(!llvm::is_contained(CommentHandlers, Handler) &&
"Comment handler already registered");
CommentHandlers.push_back(Handler);
}
void Preprocessor::removeCommentHandler(CommentHandler *Handler) {
std::vector<CommentHandler *>::iterator Pos =
llvm::find(CommentHandlers, Handler);
assert(Pos != CommentHandlers.end() && "Comment handler not registered");
CommentHandlers.erase(Pos);
}
bool Preprocessor::HandleComment(Token &result, SourceRange Comment) {
bool AnyPendingTokens = false;
for (CommentHandler *H : CommentHandlers) {
if (H->HandleComment(*this, Comment))
AnyPendingTokens = true;
}
if (!AnyPendingTokens || getCommentRetentionState())
return false;
Lex(result);
return true;
}
void Preprocessor::emitMacroDeprecationWarning(const Token &Identifier) const {
const MacroAnnotations &A =
getMacroAnnotations(Identifier.getIdentifierInfo());
assert(A.DeprecationInfo &&
"Macro deprecation warning without recorded annotation!");
const MacroAnnotationInfo &Info = *A.DeprecationInfo;
if (Info.Message.empty())
Diag(Identifier, diag::warn_pragma_deprecated_macro_use)
<< Identifier.getIdentifierInfo() << 0;
else
Diag(Identifier, diag::warn_pragma_deprecated_macro_use)
<< Identifier.getIdentifierInfo() << 1 << Info.Message;
Diag(Info.Location, diag::note_pp_macro_annotation) << 0;
}
void Preprocessor::emitRestrictExpansionWarning(const Token &Identifier) const {
const MacroAnnotations &A =
getMacroAnnotations(Identifier.getIdentifierInfo());
assert(A.RestrictExpansionInfo &&
"Macro restricted expansion warning without recorded annotation!");
const MacroAnnotationInfo &Info = *A.RestrictExpansionInfo;
if (Info.Message.empty())
Diag(Identifier, diag::warn_pragma_restrict_expansion_macro_use)
<< Identifier.getIdentifierInfo() << 0;
else
Diag(Identifier, diag::warn_pragma_restrict_expansion_macro_use)
<< Identifier.getIdentifierInfo() << 1 << Info.Message;
Diag(Info.Location, diag::note_pp_macro_annotation) << 1;
}
void Preprocessor::emitRestrictInfNaNWarning(const Token &Identifier,
unsigned DiagSelection) const {
Diag(Identifier, diag::warn_fp_nan_inf_when_disabled) << DiagSelection << 1;
}
void Preprocessor::emitFinalMacroWarning(const Token &Identifier,
bool IsUndef) const {
const MacroAnnotations &A =
getMacroAnnotations(Identifier.getIdentifierInfo());
assert(A.FinalAnnotationLoc &&
"Final macro warning without recorded annotation!");
Diag(Identifier, diag::warn_pragma_final_macro)
<< Identifier.getIdentifierInfo() << (IsUndef ? 0 : 1);
Diag(*A.FinalAnnotationLoc, diag::note_pp_macro_annotation) << 2;
}
bool Preprocessor::isSafeBufferOptOut(const SourceManager &SourceMgr,
const SourceLocation &Loc) const {
// The lambda that tests if a `Loc` is in an opt-out region given one opt-out
// region map:
auto TestInMap = [&SourceMgr](const SafeBufferOptOutRegionsTy &Map,
const SourceLocation &Loc) -> bool {
// Try to find a region in `SafeBufferOptOutMap` where `Loc` is in:
auto FirstRegionEndingAfterLoc = llvm::partition_point(
Map, [&SourceMgr,
&Loc](const std::pair<SourceLocation, SourceLocation> &Region) {
return SourceMgr.isBeforeInTranslationUnit(Region.second, Loc);
});
if (FirstRegionEndingAfterLoc != Map.end()) {
// To test if the start location of the found region precedes `Loc`:
return SourceMgr.isBeforeInTranslationUnit(
FirstRegionEndingAfterLoc->first, Loc);
}
// If we do not find a region whose end location passes `Loc`, we want to
// check if the current region is still open:
if (!Map.empty() && Map.back().first == Map.back().second)
return SourceMgr.isBeforeInTranslationUnit(Map.back().first, Loc);
return false;
};
// What the following does:
//
// If `Loc` belongs to the local TU, we just look up `SafeBufferOptOutMap`.
// Otherwise, `Loc` is from a loaded AST. We look up the
// `LoadedSafeBufferOptOutMap` first to get the opt-out region map of the
// loaded AST where `Loc` is at. Then we find if `Loc` is in an opt-out
// region w.r.t. the region map. If the region map is absent, it means there
// is no opt-out pragma in that loaded AST.
//
// Opt-out pragmas in the local TU or a loaded AST is not visible to another
// one of them. That means if you put the pragmas around a `#include
// "module.h"`, where module.h is a module, it is not actually suppressing
// warnings in module.h. This is fine because warnings in module.h will be
// reported when module.h is compiled in isolation and nothing in module.h
// will be analyzed ever again. So you will not see warnings from the file
// that imports module.h anyway. And you can't even do the same thing for PCHs
// because they can only be included from the command line.
if (SourceMgr.isLocalSourceLocation(Loc))
return TestInMap(SafeBufferOptOutMap, Loc);
const SafeBufferOptOutRegionsTy *LoadedRegions =
LoadedSafeBufferOptOutMap.lookupLoadedOptOutMap(Loc, SourceMgr);
if (LoadedRegions)
return TestInMap(*LoadedRegions, Loc);
return false;
}
bool Preprocessor::enterOrExitSafeBufferOptOutRegion(
bool isEnter, const SourceLocation &Loc) {
if (isEnter) {
if (isPPInSafeBufferOptOutRegion())
return true; // invalid enter action
InSafeBufferOptOutRegion = true;
CurrentSafeBufferOptOutStart = Loc;
// To set the start location of a new region:
if (!SafeBufferOptOutMap.empty()) {
[[maybe_unused]] auto *PrevRegion = &SafeBufferOptOutMap.back();
assert(PrevRegion->first != PrevRegion->second &&
"Shall not begin a safe buffer opt-out region before closing the "
"previous one.");
}
// If the start location equals to the end location, we call the region a
// open region or a unclosed region (i.e., end location has not been set
// yet).
SafeBufferOptOutMap.emplace_back(Loc, Loc);
} else {
if (!isPPInSafeBufferOptOutRegion())
return true; // invalid enter action
InSafeBufferOptOutRegion = false;
// To set the end location of the current open region:
assert(!SafeBufferOptOutMap.empty() &&
"Misordered safe buffer opt-out regions");
auto *CurrRegion = &SafeBufferOptOutMap.back();
assert(CurrRegion->first == CurrRegion->second &&
"Set end location to a closed safe buffer opt-out region");
CurrRegion->second = Loc;
}
return false;
}
bool Preprocessor::isPPInSafeBufferOptOutRegion() {
return InSafeBufferOptOutRegion;
}
bool Preprocessor::isPPInSafeBufferOptOutRegion(SourceLocation &StartLoc) {
StartLoc = CurrentSafeBufferOptOutStart;
return InSafeBufferOptOutRegion;
}
SmallVector<SourceLocation, 64>
Preprocessor::serializeSafeBufferOptOutMap() const {
assert(!InSafeBufferOptOutRegion &&
"Attempt to serialize safe buffer opt-out regions before file being "
"completely preprocessed");
SmallVector<SourceLocation, 64> SrcSeq;
for (const auto &[begin, end] : SafeBufferOptOutMap) {
SrcSeq.push_back(begin);
SrcSeq.push_back(end);
}
// Only `SafeBufferOptOutMap` gets serialized. No need to serialize
// `LoadedSafeBufferOptOutMap` because if this TU loads a pch/module, every
// pch/module in the pch-chain/module-DAG will be loaded one by one in order.
// It means that for each loading pch/module m, it just needs to load m's own
// `SafeBufferOptOutMap`.
return SrcSeq;
}
bool Preprocessor::setDeserializedSafeBufferOptOutMap(
const SmallVectorImpl<SourceLocation> &SourceLocations) {
if (SourceLocations.size() == 0)
return false;
assert(SourceLocations.size() % 2 == 0 &&
"ill-formed SourceLocation sequence");
auto It = SourceLocations.begin();
SafeBufferOptOutRegionsTy &Regions =
LoadedSafeBufferOptOutMap.findAndConsLoadedOptOutMap(*It, SourceMgr);
do {
SourceLocation Begin = *It++;
SourceLocation End = *It++;
Regions.emplace_back(Begin, End);
} while (It != SourceLocations.end());
return true;
}
ModuleLoader::~ModuleLoader() = default;
CommentHandler::~CommentHandler() = default;
EmptylineHandler::~EmptylineHandler() = default;
CodeCompletionHandler::~CodeCompletionHandler() = default;
void Preprocessor::createPreprocessingRecord() {
if (Record)
return;
Record = new PreprocessingRecord(getSourceManager());
addPPCallbacks(std::unique_ptr<PPCallbacks>(Record));
}
const char *Preprocessor::getCheckPoint(FileID FID, const char *Start) const {
if (auto It = CheckPoints.find(FID); It != CheckPoints.end()) {
const SmallVector<const char *> &FileCheckPoints = It->second;
const char *Last = nullptr;
// FIXME: Do better than a linear search.
for (const char *P : FileCheckPoints) {
if (P > Start)
break;
Last = P;
}
return Last;
}
return nullptr;
}
bool Preprocessor::hasSeenNoTrivialPPDirective() const {
return DirTracer && DirTracer->hasSeenNoTrivialPPDirective();
}
bool NoTrivialPPDirectiveTracer::hasSeenNoTrivialPPDirective() const {
return SeenNoTrivialPPDirective;
}
void NoTrivialPPDirectiveTracer::setSeenNoTrivialPPDirective() {
if (InMainFile && !SeenNoTrivialPPDirective)
SeenNoTrivialPPDirective = true;
}
void NoTrivialPPDirectiveTracer::LexedFileChanged(
FileID FID, LexedFileChangeReason Reason,
SrcMgr::CharacteristicKind FileType, FileID PrevFID, SourceLocation Loc) {
InMainFile = (FID == PP.getSourceManager().getMainFileID());
}
void NoTrivialPPDirectiveTracer::MacroExpands(const Token &MacroNameTok,
const MacroDefinition &MD,
SourceRange Range,
const MacroArgs *Args) {
// FIXME: Does only enable builtin macro expansion make sense?
if (!MD.getMacroInfo()->isBuiltinMacro())
setSeenNoTrivialPPDirective();
}
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