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//===- Preprocessor.h - C Language Family Preprocessor ----------*- C++ -*-===//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
/// \file
/// Defines the clang::Preprocessor interface.
#include "clang/Basic/Diagnostic.h"
#include "clang/Basic/DiagnosticIDs.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/TokenKinds.h"
#include "clang/Lex/HeaderSearch.h"
#include "clang/Lex/Lexer.h"
#include "clang/Lex/MacroInfo.h"
#include "clang/Lex/ModuleLoader.h"
#include "clang/Lex/ModuleMap.h"
#include "clang/Lex/PPCallbacks.h"
#include "clang/Lex/Token.h"
#include "clang/Lex/TokenLexer.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/FoldingSet.h"
#include "llvm/ADT/FunctionExtras.h"
#include "llvm/ADT/PointerUnion.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/TinyPtrVector.h"
#include "llvm/ADT/iterator_range.h"
#include "llvm/Support/Allocator.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/Registry.h"
#include <cassert>
#include <cstddef>
#include <cstdint>
#include <map>
#include <memory>
#include <optional>
#include <string>
#include <utility>
#include <vector>
namespace llvm {
template<unsigned InternalLen> class SmallString;
} // namespace llvm
namespace clang {
class CodeCompletionHandler;
class CommentHandler;
class DirectoryEntry;
class EmptylineHandler;
class ExternalPreprocessorSource;
class FileEntry;
class FileManager;
class HeaderSearch;
class MacroArgs;
class PragmaHandler;
class PragmaNamespace;
class PreprocessingRecord;
class PreprocessorLexer;
class PreprocessorOptions;
class ScratchBuffer;
class TargetInfo;
namespace Builtin {
class Context;
/// Stores token information for comparing actual tokens with
/// predefined values. Only handles simple tokens and identifiers.
class TokenValue {
tok::TokenKind Kind;
IdentifierInfo *II;
TokenValue(tok::TokenKind Kind) : Kind(Kind), II(nullptr) {
assert(Kind != tok::raw_identifier && "Raw identifiers are not supported.");
assert(Kind != tok::identifier &&
"Identifiers should be created by TokenValue(IdentifierInfo *)");
assert(!tok::isLiteral(Kind) && "Literals are not supported.");
assert(!tok::isAnnotation(Kind) && "Annotations are not supported.");
TokenValue(IdentifierInfo *II) : Kind(tok::identifier), II(II) {}
bool operator==(const Token &Tok) const {
return Tok.getKind() == Kind &&
(!II || II == Tok.getIdentifierInfo());
/// Context in which macro name is used.
enum MacroUse {
// other than #define or #undef
MU_Other = 0,
// macro name specified in #define
MU_Define = 1,
// macro name specified in #undef
MU_Undef = 2
/// Engages in a tight little dance with the lexer to efficiently
/// preprocess tokens.
/// Lexers know only about tokens within a single source file, and don't
/// know anything about preprocessor-level issues like the \#include stack,
/// token expansion, etc.
class Preprocessor {
friend class VAOptDefinitionContext;
friend class VariadicMacroScopeGuard;
llvm::unique_function<void(const clang::Token &)> OnToken;
std::shared_ptr<PreprocessorOptions> PPOpts;
DiagnosticsEngine *Diags;
LangOptions &LangOpts;
const TargetInfo *Target = nullptr;
const TargetInfo *AuxTarget = nullptr;
FileManager &FileMgr;
SourceManager &SourceMgr;
std::unique_ptr<ScratchBuffer> ScratchBuf;
HeaderSearch &HeaderInfo;
ModuleLoader &TheModuleLoader;
/// External source of macros.
ExternalPreprocessorSource *ExternalSource;
/// A BumpPtrAllocator object used to quickly allocate and release
/// objects internal to the Preprocessor.
llvm::BumpPtrAllocator BP;
/// Identifiers for builtin macros and other builtins.
IdentifierInfo *Ident__LINE__, *Ident__FILE__; // __LINE__, __FILE__
IdentifierInfo *Ident__DATE__, *Ident__TIME__; // __DATE__, __TIME__
IdentifierInfo *Ident__INCLUDE_LEVEL__; // __INCLUDE_LEVEL__
IdentifierInfo *Ident__BASE_FILE__; // __BASE_FILE__
IdentifierInfo *Ident__FILE_NAME__; // __FILE_NAME__
IdentifierInfo *Ident__TIMESTAMP__; // __TIMESTAMP__
IdentifierInfo *Ident__COUNTER__; // __COUNTER__
IdentifierInfo *Ident_Pragma, *Ident__pragma; // _Pragma, __pragma
IdentifierInfo *Ident__identifier; // __identifier
IdentifierInfo *Ident__VA_ARGS__; // __VA_ARGS__
IdentifierInfo *Ident__VA_OPT__; // __VA_OPT__
IdentifierInfo *Ident__has_feature; // __has_feature
IdentifierInfo *Ident__has_extension; // __has_extension
IdentifierInfo *Ident__has_builtin; // __has_builtin
IdentifierInfo *Ident__has_constexpr_builtin; // __has_constexpr_builtin
IdentifierInfo *Ident__has_attribute; // __has_attribute
IdentifierInfo *Ident__has_include; // __has_include
IdentifierInfo *Ident__has_include_next; // __has_include_next
IdentifierInfo *Ident__has_warning; // __has_warning
IdentifierInfo *Ident__is_identifier; // __is_identifier
IdentifierInfo *Ident__building_module; // __building_module
IdentifierInfo *Ident__MODULE__; // __MODULE__
IdentifierInfo *Ident__has_cpp_attribute; // __has_cpp_attribute
IdentifierInfo *Ident__has_c_attribute; // __has_c_attribute
IdentifierInfo *Ident__has_declspec; // __has_declspec_attribute
IdentifierInfo *Ident__is_target_arch; // __is_target_arch
IdentifierInfo *Ident__is_target_vendor; // __is_target_vendor
IdentifierInfo *Ident__is_target_os; // __is_target_os
IdentifierInfo *Ident__is_target_environment; // __is_target_environment
IdentifierInfo *Ident__is_target_variant_os;
IdentifierInfo *Ident__is_target_variant_environment;
IdentifierInfo *Ident__FLT_EVAL_METHOD__; // __FLT_EVAL_METHOD
// Weak, only valid (and set) while InMacroArgs is true.
Token* ArgMacro;
SourceLocation DATELoc, TIMELoc;
// FEM_UnsetOnCommandLine means that an explicit evaluation method was
// not specified on the command line. The target is queried to set the
// default evaluation method.
LangOptions::FPEvalMethodKind CurrentFPEvalMethod =
// Keeps the value of the last evaluation method before a
// `pragma float_control (precise,off) is applied.
LangOptions::FPEvalMethodKind LastFPEvalMethod =
// The most recent pragma location where the floating point evaluation
// method was modified. This is used to determine whether the
// 'pragma clang fp eval_method' was used whithin the current scope.
SourceLocation LastFPEvalPragmaLocation;
LangOptions::FPEvalMethodKind TUFPEvalMethod =
// Next __COUNTER__ value, starts at 0.
unsigned CounterValue = 0;
enum {
/// Maximum depth of \#includes.
MaxAllowedIncludeStackDepth = 200
// State that is set before the preprocessor begins.
bool KeepComments : 1;
bool KeepMacroComments : 1;
bool SuppressIncludeNotFoundError : 1;
// State that changes while the preprocessor runs:
bool InMacroArgs : 1; // True if parsing fn macro invocation args.
/// Whether the preprocessor owns the header search object.
bool OwnsHeaderSearch : 1;
/// True if macro expansion is disabled.
bool DisableMacroExpansion : 1;
/// Temporarily disables DisableMacroExpansion (i.e. enables expansion)
/// when parsing preprocessor directives.
bool MacroExpansionInDirectivesOverride : 1;
class ResetMacroExpansionHelper;
/// Whether we have already loaded macros from the external source.
mutable bool ReadMacrosFromExternalSource : 1;
/// True if pragmas are enabled.
bool PragmasEnabled : 1;
/// True if the current build action is a preprocessing action.
bool PreprocessedOutput : 1;
/// True if we are currently preprocessing a #if or #elif directive
bool ParsingIfOrElifDirective;
/// True if we are pre-expanding macro arguments.
bool InMacroArgPreExpansion;
/// Mapping/lookup information for all identifiers in
/// the program, including program keywords.
mutable IdentifierTable Identifiers;
/// This table contains all the selectors in the program.
/// Unlike IdentifierTable above, this table *isn't* populated by the
/// preprocessor. It is declared/expanded here because its role/lifetime is
/// conceptually similar to the IdentifierTable. In addition, the current
/// control flow (in clang::ParseAST()), make it convenient to put here.
/// FIXME: Make sure the lifetime of Identifiers/Selectors *isn't* tied to
/// the lifetime of the preprocessor.
SelectorTable Selectors;
/// Information about builtins.
std::unique_ptr<Builtin::Context> BuiltinInfo;
/// Tracks all of the pragmas that the client registered
/// with this preprocessor.
std::unique_ptr<PragmaNamespace> PragmaHandlers;
/// Pragma handlers of the original source is stored here during the
/// parsing of a model file.
std::unique_ptr<PragmaNamespace> PragmaHandlersBackup;
/// Tracks all of the comment handlers that the client registered
/// with this preprocessor.
std::vector<CommentHandler *> CommentHandlers;
/// Empty line handler.
EmptylineHandler *Emptyline = nullptr;
/// The kind of translation unit we are processing.
const TranslationUnitKind TUKind;
/// The code-completion handler.
CodeCompletionHandler *CodeComplete = nullptr;
/// The file that we're performing code-completion for, if any.
const FileEntry *CodeCompletionFile = nullptr;
/// The offset in file for the code-completion point.
unsigned CodeCompletionOffset = 0;
/// The location for the code-completion point. This gets instantiated
/// when the CodeCompletionFile gets \#include'ed for preprocessing.
SourceLocation CodeCompletionLoc;
/// The start location for the file of the code-completion point.
/// This gets instantiated when the CodeCompletionFile gets \#include'ed
/// for preprocessing.
SourceLocation CodeCompletionFileLoc;
/// The source location of the \c import contextual keyword we just
/// lexed, if any.
SourceLocation ModuleImportLoc;
/// The import path for named module that we're currently processing.
SmallVector<std::pair<IdentifierInfo *, SourceLocation>, 2> NamedModuleImportPath;
/// Whether the import is an `@import` or a standard c++ modules import.
bool IsAtImport = false;
/// Whether the last token we lexed was an '@'.
bool LastTokenWasAt = false;
/// A position within a C++20 import-seq.
class StdCXXImportSeq {
enum State : int {
// Positive values represent a number of unclosed brackets.
AtTopLevel = 0,
AfterTopLevelTokenSeq = -1,
AfterExport = -2,
AfterImportSeq = -3,
StdCXXImportSeq(State S) : S(S) {}
/// Saw any kind of open bracket.
void handleOpenBracket() {
S = static_cast<State>(std::max<int>(S, 0) + 1);
/// Saw any kind of close bracket other than '}'.
void handleCloseBracket() {
S = static_cast<State>(std::max<int>(S, 1) - 1);
/// Saw a close brace.
void handleCloseBrace() {
if (S == AtTopLevel && !AfterHeaderName)
S = AfterTopLevelTokenSeq;
/// Saw a semicolon.
void handleSemi() {
if (atTopLevel()) {
S = AfterTopLevelTokenSeq;
AfterHeaderName = false;
/// Saw an 'export' identifier.
void handleExport() {
if (S == AfterTopLevelTokenSeq)
S = AfterExport;
else if (S <= 0)
S = AtTopLevel;
/// Saw an 'import' identifier.
void handleImport() {
if (S == AfterTopLevelTokenSeq || S == AfterExport)
S = AfterImportSeq;
else if (S <= 0)
S = AtTopLevel;
/// Saw a 'header-name' token; do not recognize any more 'import' tokens
/// until we reach a top-level semicolon.
void handleHeaderName() {
if (S == AfterImportSeq)
AfterHeaderName = true;
/// Saw any other token.
void handleMisc() {
if (S <= 0)
S = AtTopLevel;
bool atTopLevel() { return S <= 0; }
bool afterImportSeq() { return S == AfterImportSeq; }
bool afterTopLevelSeq() { return S == AfterTopLevelTokenSeq; }
State S;
/// Whether we're in the pp-import-suffix following the header-name in a
/// pp-import. If so, a close-brace is not sufficient to end the
/// top-level-token-seq of an import-seq.
bool AfterHeaderName = false;
/// Our current position within a C++20 import-seq.
StdCXXImportSeq StdCXXImportSeqState = StdCXXImportSeq::AfterTopLevelTokenSeq;
/// Track whether we are in a Global Module Fragment
class TrackGMF {
enum GMFState : int {
GMFActive = 1,
MaybeGMF = 0,
BeforeGMFIntroducer = -1,
GMFAbsentOrEnded = -2,
TrackGMF(GMFState S) : S(S) {}
/// Saw a semicolon.
void handleSemi() {
// If it is immediately after the first instance of the module keyword,
// then that introduces the GMF.
if (S == MaybeGMF)
S = GMFActive;
/// Saw an 'export' identifier.
void handleExport() {
// The presence of an 'export' keyword always ends or excludes a GMF.
S = GMFAbsentOrEnded;
/// Saw an 'import' identifier.
void handleImport(bool AfterTopLevelTokenSeq) {
// If we see this before any 'module' kw, then we have no GMF.
if (AfterTopLevelTokenSeq && S == BeforeGMFIntroducer)
S = GMFAbsentOrEnded;
/// Saw a 'module' identifier.
void handleModule(bool AfterTopLevelTokenSeq) {
// This was the first module identifier and not preceded by any token
// that would exclude a GMF. It could begin a GMF, but only if directly
// followed by a semicolon.
if (AfterTopLevelTokenSeq && S == BeforeGMFIntroducer)
S = MaybeGMF;
S = GMFAbsentOrEnded;
/// Saw any other token.
void handleMisc() {
// We saw something other than ; after the 'module' kw, so not a GMF.
if (S == MaybeGMF)
S = GMFAbsentOrEnded;
bool inGMF() { return S == GMFActive; }
/// Track the transitions into and out of a Global Module Fragment,
/// if one is present.
GMFState S;
TrackGMF TrackGMFState = TrackGMF::BeforeGMFIntroducer;
/// Track the status of the c++20 module decl.
/// module-declaration:
/// 'export'[opt] 'module' module-name module-partition[opt]
/// attribute-specifier-seq[opt] ';'
/// module-name:
/// module-name-qualifier[opt] identifier
/// module-partition:
/// ':' module-name-qualifier[opt] identifier
/// module-name-qualifier:
/// identifier '.'
/// module-name-qualifier identifier '.'
/// Transition state:
/// NotAModuleDecl --- export ---> FoundExport
/// NotAModuleDecl --- module ---> ImplementationCandidate
/// FoundExport --- module ---> InterfaceCandidate
/// ImplementationCandidate --- Identifier ---> ImplementationCandidate
/// ImplementationCandidate --- period ---> ImplementationCandidate
/// ImplementationCandidate --- colon ---> ImplementationCandidate
/// InterfaceCandidate --- Identifier ---> InterfaceCandidate
/// InterfaceCandidate --- period ---> InterfaceCandidate
/// InterfaceCandidate --- colon ---> InterfaceCandidate
/// ImplementationCandidate --- Semi ---> NamedModuleImplementation
/// NamedModuleInterface --- Semi ---> NamedModuleInterface
/// NamedModuleImplementation --- Anything ---> NamedModuleImplementation
/// NamedModuleInterface --- Anything ---> NamedModuleInterface
/// FIXME: We haven't handle attribute-specifier-seq here. It may not be bad
/// soon since we don't support any module attributes yet.
class ModuleDeclSeq {
enum ModuleDeclState : int {
ModuleDeclSeq() : State(NotAModuleDecl) {}
void handleExport() {
if (State == NotAModuleDecl)
State = FoundExport;
else if (!isNamedModule())
void handleModule() {
if (State == FoundExport)
State = InterfaceCandidate;
else if (State == NotAModuleDecl)
State = ImplementationCandidate;
else if (!isNamedModule())
void handleIdentifier(IdentifierInfo *Identifier) {
if (isModuleCandidate() && Identifier)
Name += Identifier->getName().str();
else if (!isNamedModule())
void handleColon() {
if (isModuleCandidate())
Name += ":";
else if (!isNamedModule())
void handlePeriod() {
if (isModuleCandidate())
Name += ".";
else if (!isNamedModule())
void handleSemi() {
if (!Name.empty() && isModuleCandidate()) {
if (State == InterfaceCandidate)
State = NamedModuleInterface;
else if (State == ImplementationCandidate)
State = NamedModuleImplementation;
llvm_unreachable("Unimaged ModuleDeclState.");
} else if (!isNamedModule())
void handleMisc() {
if (!isNamedModule())
bool isModuleCandidate() const {
return State == InterfaceCandidate || State == ImplementationCandidate;
bool isNamedModule() const {
return State == NamedModuleInterface ||
State == NamedModuleImplementation;
bool isNamedInterface() const { return State == NamedModuleInterface; }
bool isImplementationUnit() const {
return State == NamedModuleImplementation && !getName().contains(':');
StringRef getName() const {
assert(isNamedModule() && "Can't get name from a non named module");
return Name;
StringRef getPrimaryName() const {
assert(isNamedModule() && "Can't get name from a non named module");
return getName().split(':').first;
void reset() {
State = NotAModuleDecl;
ModuleDeclState State;
std::string Name;
ModuleDeclSeq ModuleDeclState;
/// Whether the module import expects an identifier next. Otherwise,
/// it expects a '.' or ';'.
bool ModuleImportExpectsIdentifier = false;
/// The identifier and source location of the currently-active
/// \#pragma clang arc_cf_code_audited begin.
std::pair<IdentifierInfo *, SourceLocation> PragmaARCCFCodeAuditedInfo;
/// The source location of the currently-active
/// \#pragma clang assume_nonnull begin.
SourceLocation PragmaAssumeNonNullLoc;
/// Set only for preambles which end with an active
/// \#pragma clang assume_nonnull begin.
/// When the preamble is loaded into the main file,
/// `PragmaAssumeNonNullLoc` will be set to this to
/// replay the unterminated assume_nonnull.
SourceLocation PreambleRecordedPragmaAssumeNonNullLoc;
/// True if we hit the code-completion point.
bool CodeCompletionReached = false;
/// The code completion token containing the information
/// on the stem that is to be code completed.
IdentifierInfo *CodeCompletionII = nullptr;
/// Range for the code completion token.
SourceRange CodeCompletionTokenRange;
/// The directory that the main file should be considered to occupy,
/// if it does not correspond to a real file (as happens when building a
/// module).
const DirectoryEntry *MainFileDir = nullptr;
/// The number of bytes that we will initially skip when entering the
/// main file, along with a flag that indicates whether skipping this number
/// of bytes will place the lexer at the start of a line.
/// This is used when loading a precompiled preamble.
std::pair<int, bool> SkipMainFilePreamble;
/// Whether we hit an error due to reaching max allowed include depth. Allows
/// to avoid hitting the same error over and over again.
bool HasReachedMaxIncludeDepth = false;
/// The number of currently-active calls to Lex.
/// Lex is reentrant, and asking for an (end-of-phase-4) token can often
/// require asking for multiple additional tokens. This counter makes it
/// possible for Lex to detect whether it's producing a token for the end
/// of phase 4 of translation or for some other situation.
unsigned LexLevel = 0;
/// The number of (LexLevel 0) preprocessor tokens.
unsigned TokenCount = 0;
/// Preprocess every token regardless of LexLevel.
bool PreprocessToken = false;
/// The maximum number of (LexLevel 0) tokens before issuing a -Wmax-tokens
/// warning, or zero for unlimited.
unsigned MaxTokens = 0;
SourceLocation MaxTokensOverrideLoc;
struct PreambleSkipInfo {
SourceLocation HashTokenLoc;
SourceLocation IfTokenLoc;
bool FoundNonSkipPortion;
bool FoundElse;
SourceLocation ElseLoc;
PreambleSkipInfo(SourceLocation HashTokenLoc, SourceLocation IfTokenLoc,
bool FoundNonSkipPortion, bool FoundElse,
SourceLocation ElseLoc)
: HashTokenLoc(HashTokenLoc), IfTokenLoc(IfTokenLoc),
FoundNonSkipPortion(FoundNonSkipPortion), FoundElse(FoundElse),
ElseLoc(ElseLoc) {}
using IncludedFilesSet = llvm::DenseSet<const FileEntry *>;
friend class ASTReader;
friend class MacroArgs;
class PreambleConditionalStackStore {
enum State {
Off = 0,
Recording = 1,
Replaying = 2,
PreambleConditionalStackStore() = default;
void startRecording() { ConditionalStackState = Recording; }
void startReplaying() { ConditionalStackState = Replaying; }
bool isRecording() const { return ConditionalStackState == Recording; }
bool isReplaying() const { return ConditionalStackState == Replaying; }
ArrayRef<PPConditionalInfo> getStack() const {
return ConditionalStack;
void doneReplaying() {
ConditionalStackState = Off;
void setStack(ArrayRef<PPConditionalInfo> s) {
if (!isRecording() && !isReplaying())
ConditionalStack.append(s.begin(), s.end());
bool hasRecordedPreamble() const { return !ConditionalStack.empty(); }
bool reachedEOFWhileSkipping() const { return SkipInfo.has_value(); }
void clearSkipInfo() { SkipInfo.reset(); }
std::optional<PreambleSkipInfo> SkipInfo;
SmallVector<PPConditionalInfo, 4> ConditionalStack;
State ConditionalStackState = Off;
} PreambleConditionalStack;
/// The current top of the stack that we're lexing from if
/// not expanding a macro and we are lexing directly from source code.
/// Only one of CurLexer, or CurTokenLexer will be non-null.
std::unique_ptr<Lexer> CurLexer;
/// The current top of the stack what we're lexing from
/// if not expanding a macro.
/// This is an alias for CurLexer.
PreprocessorLexer *CurPPLexer = nullptr;
/// Used to find the current FileEntry, if CurLexer is non-null
/// and if applicable.
/// This allows us to implement \#include_next and find directory-specific
/// properties.
ConstSearchDirIterator CurDirLookup = nullptr;
/// The current macro we are expanding, if we are expanding a macro.
/// One of CurLexer and CurTokenLexer must be null.
std::unique_ptr<TokenLexer> CurTokenLexer;
/// The kind of lexer we're currently working with.
enum CurLexerKind {
} CurLexerKind = CLK_Lexer;
/// If the current lexer is for a submodule that is being built, this
/// is that submodule.
Module *CurLexerSubmodule = nullptr;
/// Keeps track of the stack of files currently
/// \#included, and macros currently being expanded from, not counting
/// CurLexer/CurTokenLexer.
struct IncludeStackInfo {
enum CurLexerKind CurLexerKind;
Module *TheSubmodule;
std::unique_ptr<Lexer> TheLexer;
PreprocessorLexer *ThePPLexer;
std::unique_ptr<TokenLexer> TheTokenLexer;
ConstSearchDirIterator TheDirLookup;
// The following constructors are completely useless copies of the default
// versions, only needed to pacify MSVC.
IncludeStackInfo(enum CurLexerKind CurLexerKind, Module *TheSubmodule,
std::unique_ptr<Lexer> &&TheLexer,
PreprocessorLexer *ThePPLexer,
std::unique_ptr<TokenLexer> &&TheTokenLexer,
ConstSearchDirIterator TheDirLookup)
: CurLexerKind(std::move(CurLexerKind)),
TheSubmodule(std::move(TheSubmodule)), TheLexer(std::move(TheLexer)),
TheDirLookup(std::move(TheDirLookup)) {}
std::vector<IncludeStackInfo> IncludeMacroStack;
/// Actions invoked when some preprocessor activity is
/// encountered (e.g. a file is \#included, etc).
std::unique_ptr<PPCallbacks> Callbacks;
struct MacroExpandsInfo {
Token Tok;
MacroDefinition MD;
SourceRange Range;
MacroExpandsInfo(Token Tok, MacroDefinition MD, SourceRange Range)
: Tok(Tok), MD(MD), Range(Range) {}
SmallVector<MacroExpandsInfo, 2> DelayedMacroExpandsCallbacks;
/// Information about a name that has been used to define a module macro.
struct ModuleMacroInfo {
/// The most recent macro directive for this identifier.
MacroDirective *MD;
/// The active module macros for this identifier.
llvm::TinyPtrVector<ModuleMacro *> ActiveModuleMacros;
/// The generation number at which we last updated ActiveModuleMacros.
/// \see Preprocessor::VisibleModules.
unsigned ActiveModuleMacrosGeneration = 0;
/// Whether this macro name is ambiguous.
bool IsAmbiguous = false;
/// The module macros that are overridden by this macro.
llvm::TinyPtrVector<ModuleMacro *> OverriddenMacros;
ModuleMacroInfo(MacroDirective *MD) : MD(MD) {}
/// The state of a macro for an identifier.
class MacroState {
mutable llvm::PointerUnion<MacroDirective *, ModuleMacroInfo *> State;
ModuleMacroInfo *getModuleInfo(Preprocessor &PP,
const IdentifierInfo *II) const {
if (II->isOutOfDate())
// FIXME: Find a spare bit on IdentifierInfo and store a
// HasModuleMacros flag.
if (!II->hasMacroDefinition() ||
(!PP.getLangOpts().Modules &&
!PP.getLangOpts().ModulesLocalVisibility) ||
return nullptr;
auto *Info = State.dyn_cast<ModuleMacroInfo*>();
if (!Info) {
Info = new (PP.getPreprocessorAllocator())
ModuleMacroInfo(State.get<MacroDirective *>());
State = Info;
if (PP.CurSubmoduleState->VisibleModules.getGeneration() !=
PP.updateModuleMacroInfo(II, *Info);
return Info;
MacroState() : MacroState(nullptr) {}
MacroState(MacroDirective *MD) : State(MD) {}
MacroState(MacroState &&O) noexcept : State(O.State) {
O.State = (MacroDirective *)nullptr;
MacroState &operator=(MacroState &&O) noexcept {
auto S = O.State;
O.State = (MacroDirective *)nullptr;
State = S;
return *this;
~MacroState() {
if (auto *Info = State.dyn_cast<ModuleMacroInfo*>())
MacroDirective *getLatest() const {
if (auto *Info = State.dyn_cast<ModuleMacroInfo*>())
return Info->MD;
return State.get<MacroDirective*>();
void setLatest(MacroDirective *MD) {
if (auto *Info = State.dyn_cast<ModuleMacroInfo*>())
Info->MD = MD;
State = MD;
bool isAmbiguous(Preprocessor &PP, const IdentifierInfo *II) const {
auto *Info = getModuleInfo(PP, II);
return Info ? Info->IsAmbiguous : false;
ArrayRef<ModuleMacro *>
getActiveModuleMacros(Preprocessor &PP, const IdentifierInfo *II) const {
if (auto *Info = getModuleInfo(PP, II))
return Info->ActiveModuleMacros;
return std::nullopt;
MacroDirective::DefInfo findDirectiveAtLoc(SourceLocation Loc,
SourceManager &SourceMgr) const {
// FIXME: Incorporate module macros into the result of this.
if (auto *Latest = getLatest())
return Latest->findDirectiveAtLoc(Loc, SourceMgr);
return {};
void overrideActiveModuleMacros(Preprocessor &PP, IdentifierInfo *II) {
if (auto *Info = getModuleInfo(PP, II)) {
Info->IsAmbiguous = false;
ArrayRef<ModuleMacro*> getOverriddenMacros() const {
if (auto *Info = State.dyn_cast<ModuleMacroInfo*>())
return Info->OverriddenMacros;
return std::nullopt;
void setOverriddenMacros(Preprocessor &PP,
ArrayRef<ModuleMacro *> Overrides) {
auto *Info = State.dyn_cast<ModuleMacroInfo*>();
if (!Info) {
if (Overrides.empty())
Info = new (PP.getPreprocessorAllocator())
ModuleMacroInfo(State.get<MacroDirective *>());
State = Info;
Overrides.begin(), Overrides.end());
Info->ActiveModuleMacrosGeneration = 0;
/// For each IdentifierInfo that was associated with a macro, we
/// keep a mapping to the history of all macro definitions and #undefs in
/// the reverse order (the latest one is in the head of the list).
/// This mapping lives within the \p CurSubmoduleState.
using MacroMap = llvm::DenseMap<const IdentifierInfo *, MacroState>;
struct SubmoduleState;
/// Information about a submodule that we're currently building.
struct BuildingSubmoduleInfo {
/// The module that we are building.
Module *M;
/// The location at which the module was included.
SourceLocation ImportLoc;
/// Whether we entered this submodule via a pragma.
bool IsPragma;
/// The previous SubmoduleState.
SubmoduleState *OuterSubmoduleState;
/// The number of pending module macro names when we started building this.
unsigned OuterPendingModuleMacroNames;
BuildingSubmoduleInfo(Module *M, SourceLocation ImportLoc, bool IsPragma,
SubmoduleState *OuterSubmoduleState,
unsigned OuterPendingModuleMacroNames)
: M(M), ImportLoc(ImportLoc), IsPragma(IsPragma),
OuterPendingModuleMacroNames(OuterPendingModuleMacroNames) {}
SmallVector<BuildingSubmoduleInfo, 8> BuildingSubmoduleStack;
/// Information about a submodule's preprocessor state.
struct SubmoduleState {
/// The macros for the submodule.
MacroMap Macros;
/// The set of modules that are visible within the submodule.
VisibleModuleSet VisibleModules;
// FIXME: CounterValue?
// FIXME: PragmaPushMacroInfo?
std::map<Module *, SubmoduleState> Submodules;
/// The preprocessor state for preprocessing outside of any submodule.
SubmoduleState NullSubmoduleState;
/// The current submodule state. Will be \p NullSubmoduleState if we're not
/// in a submodule.
SubmoduleState *CurSubmoduleState;
/// The files that have been included.
IncludedFilesSet IncludedFiles;
/// The set of top-level modules that affected preprocessing, but were not
/// imported.
llvm::SmallSetVector<Module *, 2> AffectingClangModules;
/// The set of known macros exported from modules.
llvm::FoldingSet<ModuleMacro> ModuleMacros;
/// The names of potential module macros that we've not yet processed.
llvm::SmallVector<const IdentifierInfo *, 32> PendingModuleMacroNames;
/// The list of module macros, for each identifier, that are not overridden by
/// any other module macro.
llvm::DenseMap<const IdentifierInfo *, llvm::TinyPtrVector<ModuleMacro *>>
/// Macros that we want to warn because they are not used at the end
/// of the translation unit.
/// We store just their SourceLocations instead of
/// something like MacroInfo*. The benefit of this is that when we are
/// deserializing from PCH, we don't need to deserialize identifier & macros
/// just so that we can report that they are unused, we just warn using
/// the SourceLocations of this set (that will be filled by the ASTReader).
using WarnUnusedMacroLocsTy = llvm::SmallDenseSet<SourceLocation, 32>;
WarnUnusedMacroLocsTy WarnUnusedMacroLocs;
/// This is a pair of an optional message and source location used for pragmas
/// that annotate macros like pragma clang restrict_expansion and pragma clang
/// deprecated. This pair stores the optional message and the location of the
/// annotation pragma for use producing diagnostics and notes.
using MsgLocationPair = std::pair<std::string, SourceLocation>;
struct MacroAnnotationInfo {
SourceLocation Location;
std::string Message;
struct MacroAnnotations {
std::optional<MacroAnnotationInfo> DeprecationInfo;
std::optional<MacroAnnotationInfo> RestrictExpansionInfo;
std::optional<SourceLocation> FinalAnnotationLoc;
static MacroAnnotations makeDeprecation(SourceLocation Loc,
std::string Msg) {
return MacroAnnotations{MacroAnnotationInfo{Loc, std::move(Msg)},
std::nullopt, std::nullopt};
static MacroAnnotations makeRestrictExpansion(SourceLocation Loc,
std::string Msg) {
return MacroAnnotations{
std::nullopt, MacroAnnotationInfo{Loc, std::move(Msg)}, std::nullopt};
static MacroAnnotations makeFinal(SourceLocation Loc) {
return MacroAnnotations{std::nullopt, std::nullopt, Loc};
/// Warning information for macro annotations.
llvm::DenseMap<const IdentifierInfo *, MacroAnnotations> AnnotationInfos;
/// A "freelist" of MacroArg objects that can be
/// reused for quick allocation.
MacroArgs *MacroArgCache = nullptr;
/// For each IdentifierInfo used in a \#pragma push_macro directive,
/// we keep a MacroInfo stack used to restore the previous macro value.
llvm::DenseMap<IdentifierInfo *, std::vector<MacroInfo *>>
// Various statistics we track for performance analysis.
unsigned NumDirectives = 0;
unsigned NumDefined = 0;
unsigned NumUndefined = 0;
unsigned NumPragma = 0;
unsigned NumIf = 0;
unsigned NumElse = 0;
unsigned NumEndif = 0;
unsigned NumEnteredSourceFiles = 0;
unsigned MaxIncludeStackDepth = 0;
unsigned NumMacroExpanded = 0;
unsigned NumFnMacroExpanded = 0;
unsigned NumBuiltinMacroExpanded = 0;
unsigned NumFastMacroExpanded = 0;
unsigned NumTokenPaste = 0;
unsigned NumFastTokenPaste = 0;
unsigned NumSkipped = 0;
/// The predefined macros that preprocessor should use from the
/// command line etc.
std::string Predefines;
/// The file ID for the preprocessor predefines.
FileID PredefinesFileID;
/// The file ID for the PCH through header.
FileID PCHThroughHeaderFileID;
/// Whether tokens are being skipped until a #pragma hdrstop is seen.
bool SkippingUntilPragmaHdrStop = false;
/// Whether tokens are being skipped until the through header is seen.
bool SkippingUntilPCHThroughHeader = false;
/// \{
/// Cache of macro expanders to reduce malloc traffic.
enum { TokenLexerCacheSize = 8 };
unsigned NumCachedTokenLexers;
std::unique_ptr<TokenLexer> TokenLexerCache[TokenLexerCacheSize];
/// \}
/// Keeps macro expanded tokens for TokenLexers.
/// Works like a stack; a TokenLexer adds the macro expanded tokens that is
/// going to lex in the cache and when it finishes the tokens are removed
/// from the end of the cache.
SmallVector<Token, 16> MacroExpandedTokens;
std::vector<std::pair<TokenLexer *, size_t>> MacroExpandingLexersStack;
/// A record of the macro definitions and expansions that
/// occurred during preprocessing.
/// This is an optional side structure that can be enabled with
/// \c createPreprocessingRecord() prior to preprocessing.
PreprocessingRecord *Record = nullptr;
/// Cached tokens state.
using CachedTokensTy = SmallVector<Token, 1>;
/// Cached tokens are stored here when we do backtracking or
/// lookahead. They are "lexed" by the CachingLex() method.
CachedTokensTy CachedTokens;
/// The position of the cached token that CachingLex() should
/// "lex" next.
/// If it points beyond the CachedTokens vector, it means that a normal
/// Lex() should be invoked.
CachedTokensTy::size_type CachedLexPos = 0;
/// Stack of backtrack positions, allowing nested backtracks.
/// The EnableBacktrackAtThisPos() method pushes a position to
/// indicate where CachedLexPos should be set when the BackTrack() method is
/// invoked (at which point the last position is popped).
std::vector<CachedTokensTy::size_type> BacktrackPositions;
/// True if \p Preprocessor::SkipExcludedConditionalBlock() is running.
/// This is used to guard against calling this function recursively.
/// See comments at the use-site for more context about why it is needed.
bool SkippingExcludedConditionalBlock = false;
/// Keeps track of skipped range mappings that were recorded while skipping
/// excluded conditional directives. It maps the source buffer pointer at
/// the beginning of a skipped block, to the number of bytes that should be
/// skipped.
llvm::DenseMap<const char *, unsigned> RecordedSkippedRanges;
void updateOutOfDateIdentifier(IdentifierInfo &II) const;
Preprocessor(std::shared_ptr<PreprocessorOptions> PPOpts,
DiagnosticsEngine &diags, LangOptions &opts, SourceManager &SM,
HeaderSearch &Headers, ModuleLoader &TheModuleLoader,
IdentifierInfoLookup *IILookup = nullptr,
bool OwnsHeaderSearch = false,
TranslationUnitKind TUKind = TU_Complete);
/// Initialize the preprocessor using information about the target.
/// \param Target is owned by the caller and must remain valid for the
/// lifetime of the preprocessor.
/// \param AuxTarget is owned by the caller and must remain valid for
/// the lifetime of the preprocessor.
void Initialize(const TargetInfo &Target,
const TargetInfo *AuxTarget = nullptr);
/// Initialize the preprocessor to parse a model file
/// To parse model files the preprocessor of the original source is reused to
/// preserver the identifier table. However to avoid some duplicate
/// information in the preprocessor some cleanup is needed before it is used
/// to parse model files. This method does that cleanup.
void InitializeForModelFile();
/// Cleanup after model file parsing
void FinalizeForModelFile();
/// Retrieve the preprocessor options used to initialize this
/// preprocessor.
PreprocessorOptions &getPreprocessorOpts() const { return *PPOpts; }
DiagnosticsEngine &getDiagnostics() const { return *Diags; }
void setDiagnostics(DiagnosticsEngine &D) { Diags = &D; }
const LangOptions &getLangOpts() const { return LangOpts; }
const TargetInfo &getTargetInfo() const { return *Target; }
const TargetInfo *getAuxTargetInfo() const { return AuxTarget; }
FileManager &getFileManager() const { return FileMgr; }
SourceManager &getSourceManager() const { return SourceMgr; }
HeaderSearch &getHeaderSearchInfo() const { return HeaderInfo; }
IdentifierTable &getIdentifierTable() { return Identifiers; }
const IdentifierTable &getIdentifierTable() const { return Identifiers; }
SelectorTable &getSelectorTable() { return Selectors; }
Builtin::Context &getBuiltinInfo() { return *BuiltinInfo; }
llvm::BumpPtrAllocator &getPreprocessorAllocator() { return BP; }
void setExternalSource(ExternalPreprocessorSource *Source) {
ExternalSource = Source;
ExternalPreprocessorSource *getExternalSource() const {
return ExternalSource;
/// Retrieve the module loader associated with this preprocessor.
ModuleLoader &getModuleLoader() const { return TheModuleLoader; }
bool hadModuleLoaderFatalFailure() const {
return TheModuleLoader.HadFatalFailure;
/// Retrieve the number of Directives that have been processed by the
/// Preprocessor.
unsigned getNumDirectives() const {
return NumDirectives;
/// True if we are currently preprocessing a #if or #elif directive
bool isParsingIfOrElifDirective() const {
return ParsingIfOrElifDirective;
/// Control whether the preprocessor retains comments in output.
void SetCommentRetentionState(bool KeepComments, bool KeepMacroComments) {
this->KeepComments = KeepComments | KeepMacroComments;
this->KeepMacroComments = KeepMacroComments;
bool getCommentRetentionState() const { return KeepComments; }
void setPragmasEnabled(bool Enabled) { PragmasEnabled = Enabled; }
bool getPragmasEnabled() const { return PragmasEnabled; }
void SetSuppressIncludeNotFoundError(bool Suppress) {
SuppressIncludeNotFoundError = Suppress;
bool GetSuppressIncludeNotFoundError() {
return SuppressIncludeNotFoundError;
/// Sets whether the preprocessor is responsible for producing output or if
/// it is producing tokens to be consumed by Parse and Sema.
void setPreprocessedOutput(bool IsPreprocessedOutput) {
PreprocessedOutput = IsPreprocessedOutput;
/// Returns true if the preprocessor is responsible for generating output,
/// false if it is producing tokens to be consumed by Parse and Sema.
bool isPreprocessedOutput() const { return PreprocessedOutput; }
/// Return true if we are lexing directly from the specified lexer.
bool isCurrentLexer(const PreprocessorLexer *L) const {
return CurPPLexer == L;
/// Return the current lexer being lexed from.
/// Note that this ignores any potentially active macro expansions and _Pragma
/// expansions going on at the time.
PreprocessorLexer *getCurrentLexer() const { return CurPPLexer; }
/// Return the current file lexer being lexed from.
/// Note that this ignores any potentially active macro expansions and _Pragma
/// expansions going on at the time.
PreprocessorLexer *getCurrentFileLexer() const;
/// Return the submodule owning the file being lexed. This may not be
/// the current module if we have changed modules since entering the file.
Module *getCurrentLexerSubmodule() const { return CurLexerSubmodule; }
/// Returns the FileID for the preprocessor predefines.
FileID getPredefinesFileID() const { return PredefinesFileID; }
/// \{
/// Accessors for preprocessor callbacks.
/// Note that this class takes ownership of any PPCallbacks object given to
/// it.
PPCallbacks *getPPCallbacks() const { return Callbacks.get(); }
void addPPCallbacks(std::unique_ptr<PPCallbacks> C) {
if (Callbacks)
C = std::make_unique<PPChainedCallbacks>(std::move(C),
Callbacks = std::move(C);
/// \}
/// Get the number of tokens processed so far.
unsigned getTokenCount() const { return TokenCount; }
/// Get the max number of tokens before issuing a -Wmax-tokens warning.
unsigned getMaxTokens() const { return MaxTokens; }
void overrideMaxTokens(unsigned Value, SourceLocation Loc) {
MaxTokens = Value;
MaxTokensOverrideLoc = Loc;
SourceLocation getMaxTokensOverrideLoc() const { return MaxTokensOverrideLoc; }
/// Register a function that would be called on each token in the final
/// expanded token stream.
/// This also reports annotation tokens produced by the parser.
void setTokenWatcher(llvm::unique_function<void(const clang::Token &)> F) {
OnToken = std::move(F);
void setPreprocessToken(bool Preprocess) { PreprocessToken = Preprocess; }
bool isMacroDefined(StringRef Id) {
return isMacroDefined(&Identifiers.get(Id));
bool isMacroDefined(const IdentifierInfo *II) {
return II->hasMacroDefinition() &&
(!getLangOpts().Modules || (bool)getMacroDefinition(II));
/// Determine whether II is defined as a macro within the module M,
/// if that is a module that we've already preprocessed. Does not check for
/// macros imported into M.
bool isMacroDefinedInLocalModule(const IdentifierInfo *II, Module *M) {
if (!II->hasMacroDefinition())
return false;
auto I = Submodules.find(M);
if (I == Submodules.end())
return false;
auto J = I->second.Macros.find(II);
if (J == I->second.Macros.end())
return false;
auto *MD = J->second.getLatest();
return MD && MD->isDefined();
MacroDefinition getMacroDefinition(const IdentifierInfo *II) {
if (!II->hasMacroDefinition())
return {};
MacroState &S = CurSubmoduleState->Macros[II];
auto *MD = S.getLatest();
while (MD && isa<VisibilityMacroDirective>(MD))
MD = MD->getPrevious();
return MacroDefinition(dyn_cast_or_null<DefMacroDirective>(MD),
S.getActiveModuleMacros(*this, II),
S.isAmbiguous(*this, II));
MacroDefinition getMacroDefinitionAtLoc(const IdentifierInfo *II,
SourceLocation Loc) {
if (!II->hadMacroDefinition())
return {};
MacroState &S = CurSubmoduleState->Macros[II];
MacroDirective::DefInfo DI;
if (auto *MD = S.getLatest())
DI = MD->findDirectiveAtLoc(Loc, getSourceManager());
// FIXME: Compute the set of active module macros at the specified location.
return MacroDefinition(DI.getDirective(),
S.getActiveModuleMacros(*this, II),
S.isAmbiguous(*this, II));
/// Given an identifier, return its latest non-imported MacroDirective
/// if it is \#define'd and not \#undef'd, or null if it isn't \#define'd.
MacroDirective *getLocalMacroDirective(const IdentifierInfo *II) const {
if (!II->hasMacroDefinition())
return nullptr;
auto *MD = getLocalMacroDirectiveHistory(II);
if (!MD || MD->getDefinition().isUndefined())
return nullptr;
return MD;
const MacroInfo *getMacroInfo(const IdentifierInfo *II) const {
return const_cast<Preprocessor*>(this)->getMacroInfo(II);
MacroInfo *getMacroInfo(const IdentifierInfo *II) {
if (!II->hasMacroDefinition())
return nullptr;
if (auto MD = getMacroDefinition(II))
return MD.getMacroInfo();
return nullptr;
/// Given an identifier, return the latest non-imported macro
/// directive for that identifier.
/// One can iterate over all previous macro directives from the most recent
/// one.
MacroDirective *getLocalMacroDirectiveHistory(const IdentifierInfo *II) const;
/// Add a directive to the macro directive history for this identifier.
void appendMacroDirective(IdentifierInfo *II, MacroDirective *MD);
DefMacroDirective *appendDefMacroDirective(IdentifierInfo *II, MacroInfo *MI,
SourceLocation Loc) {
DefMacroDirective *MD = AllocateDefMacroDirective(MI, Loc);
appendMacroDirective(II, MD);
return MD;
DefMacroDirective *appendDefMacroDirective(IdentifierInfo *II,
MacroInfo *MI) {
return appendDefMacroDirective(II, MI, MI->getDefinitionLoc());
/// Set a MacroDirective that was loaded from a PCH file.
void setLoadedMacroDirective(IdentifierInfo *II, MacroDirective *ED,
MacroDirective *MD);
/// Register an exported macro for a module and identifier.
ModuleMacro *addModuleMacro(Module *Mod, IdentifierInfo *II, MacroInfo *Macro,
ArrayRef<ModuleMacro *> Overrides, bool &IsNew);
ModuleMacro *getModuleMacro(Module *Mod, const IdentifierInfo *II);
/// Get the list of leaf (non-overridden) module macros for a name.
ArrayRef<ModuleMacro*> getLeafModuleMacros(const IdentifierInfo *II) const {
if (II->isOutOfDate())
auto I = LeafModuleMacros.find(II);
if (I != LeafModuleMacros.end())
return I->second;
return std::nullopt;
/// Get the list of submodules that we're currently building.
ArrayRef<BuildingSubmoduleInfo> getBuildingSubmodules() const {
return BuildingSubmoduleStack;
/// \{
/// Iterators for the macro history table. Currently defined macros have
/// IdentifierInfo::hasMacroDefinition() set and an empty
/// MacroInfo::getUndefLoc() at the head of the list.
using macro_iterator = MacroMap::const_iterator;
macro_iterator macro_begin(bool IncludeExternalMacros = true) const;
macro_iterator macro_end(bool IncludeExternalMacros = true) const;
macros(bool IncludeExternalMacros = true) const {
macro_iterator begin = macro_begin(IncludeExternalMacros);
macro_iterator end = macro_end(IncludeExternalMacros);
return llvm::make_range(begin, end);
/// \}
/// Mark the given clang module as affecting the current clang module or translation unit.
void markClangModuleAsAffecting(Module *M) {
if (!BuildingSubmoduleStack.empty()) {
if (M != BuildingSubmoduleStack.back().M)
} else {
/// Get the set of top-level clang modules that affected preprocessing, but were not
/// imported.
const llvm::SmallSetVector<Module *, 2> &getAffectingClangModules() const {
return AffectingClangModules;
/// Mark the file as included.
/// Returns true if this is the first time the file was included.
bool markIncluded(const FileEntry *File) {
return IncludedFiles.insert(File).second;
/// Return true if this header has already been included.
bool alreadyIncluded(const FileEntry *File) const {
return IncludedFiles.count(File);
/// Get the set of included files.
IncludedFilesSet &getIncludedFiles() { return IncludedFiles; }
const IncludedFilesSet &getIncludedFiles() const { return IncludedFiles; }
/// Return the name of the macro defined before \p Loc that has
/// spelling \p Tokens. If there are multiple macros with same spelling,
/// return the last one defined.
StringRef getLastMacroWithSpelling(SourceLocation Loc,
ArrayRef<TokenValue> Tokens) const;
/// Get the predefines for this processor.
/// Used by some third-party tools to inspect and add predefines (see
const std::string &getPredefines() const { return Predefines; }
/// Set the predefines for this Preprocessor.
/// These predefines are automatically injected when parsing the main file.
void setPredefines(std::string P) { Predefines = std::move(P); }
/// Return information about the specified preprocessor
/// identifier token.
IdentifierInfo *getIdentifierInfo(StringRef Name) const {
return &Identifiers.get(Name);
/// Add the specified pragma handler to this preprocessor.
/// If \p Namespace is non-null, then it is a token required to exist on the
/// pragma line before the pragma string starts, e.g. "STDC" or "GCC".
void AddPragmaHandler(StringRef Namespace, PragmaHandler *Handler);
void AddPragmaHandler(PragmaHandler *Handler) {
AddPragmaHandler(StringRef(), Handler);
/// Remove the specific pragma handler from this preprocessor.
/// If \p Namespace is non-null, then it should be the namespace that
/// \p Handler was added to. It is an error to remove a handler that
/// has not been registered.
void RemovePragmaHandler(StringRef Namespace, PragmaHandler *Handler);
void RemovePragmaHandler(PragmaHandler *Handler) {
RemovePragmaHandler(StringRef(), Handler);
/// Install empty handlers for all pragmas (making them ignored).
void IgnorePragmas();
/// Set empty line handler.
void setEmptylineHandler(EmptylineHandler *Handler) { Emptyline = Handler; }
EmptylineHandler *getEmptylineHandler() const { return Emptyline; }
/// Add the specified comment handler to the preprocessor.
void addCommentHandler(CommentHandler *Handler);
/// Remove the specified comment handler.
/// It is an error to remove a handler that has not been registered.
void removeCommentHandler(CommentHandler *Handler);
/// Set the code completion handler to the given object.
void setCodeCompletionHandler(CodeCompletionHandler &Handler) {
CodeComplete = &Handler;
/// Retrieve the current code-completion handler.
CodeCompletionHandler *getCodeCompletionHandler() const {
return CodeComplete;
/// Clear out the code completion handler.
void clearCodeCompletionHandler() {
CodeComplete = nullptr;
/// Hook used by the lexer to invoke the "included file" code
/// completion point.
void CodeCompleteIncludedFile(llvm::StringRef Dir, bool IsAngled);
/// Hook used by the lexer to invoke the "natural language" code
/// completion point.
void CodeCompleteNaturalLanguage();
/// Set the code completion token for filtering purposes.
void setCodeCompletionIdentifierInfo(IdentifierInfo *Filter) {
CodeCompletionII = Filter;
/// Set the code completion token range for detecting replacement range later
/// on.
void setCodeCompletionTokenRange(const SourceLocation Start,
const SourceLocation End) {
CodeCompletionTokenRange = {Start, End};
SourceRange getCodeCompletionTokenRange() const {
return CodeCompletionTokenRange;
/// Get the code completion token for filtering purposes.
StringRef getCodeCompletionFilter() {
if (CodeCompletionII)
return CodeCompletionII->getName();
return {};
/// Retrieve the preprocessing record, or NULL if there is no
/// preprocessing record.
PreprocessingRecord *getPreprocessingRecord() const { return Record; }
/// Create a new preprocessing record, which will keep track of
/// all macro expansions, macro definitions, etc.
void createPreprocessingRecord();
/// Returns true if the FileEntry is the PCH through header.
bool isPCHThroughHeader(const FileEntry *FE);
/// True if creating a PCH with a through header.
bool creatingPCHWithThroughHeader();
/// True if using a PCH with a through header.
bool usingPCHWithThroughHeader();
/// True if creating a PCH with a #pragma hdrstop.
bool creatingPCHWithPragmaHdrStop();
/// True if using a PCH with a #pragma hdrstop.
bool usingPCHWithPragmaHdrStop();
/// Skip tokens until after the #include of the through header or
/// until after a #pragma hdrstop.
void SkipTokensWhileUsingPCH();
/// Process directives while skipping until the through header or
/// #pragma hdrstop is found.
void HandleSkippedDirectiveWhileUsingPCH(Token &Result,
SourceLocation HashLoc);
/// Enter the specified FileID as the main source file,
/// which implicitly adds the builtin defines etc.
void EnterMainSourceFile();
/// Inform the preprocessor callbacks that processing is complete.
void EndSourceFile();
/// Add a source file to the top of the include stack and
/// start lexing tokens from it instead of the current buffer.
/// Emits a diagnostic, doesn't enter the file, and returns true on error.
bool EnterSourceFile(FileID FID, ConstSearchDirIterator Dir,
SourceLocation Loc, bool IsFirstIncludeOfFile = true);
/// Add a Macro to the top of the include stack and start lexing
/// tokens from it instead of the current buffer.
/// \param Args specifies the tokens input to a function-like macro.
/// \param ILEnd specifies the location of the ')' for a function-like macro
/// or the identifier for an object-like macro.
void EnterMacro(Token &Tok, SourceLocation ILEnd, MacroInfo *Macro,
MacroArgs *Args);
/// Add a "macro" context to the top of the include stack,
/// which will cause the lexer to start returning the specified tokens.
/// If \p DisableMacroExpansion is true, tokens lexed from the token stream
/// will not be subject to further macro expansion. Otherwise, these tokens
/// will be re-macro-expanded when/if expansion is enabled.
/// If \p OwnsTokens is false, this method assumes that the specified stream
/// of tokens has a permanent owner somewhere, so they do not need to be
/// copied. If it is true, it assumes the array of tokens is allocated with
/// \c new[] and the Preprocessor will delete[] it.
/// If \p IsReinject the resulting tokens will have Token::IsReinjected flag
/// set, see the flag documentation for details.
void EnterTokenStream(const Token *Toks, unsigned NumToks,
bool DisableMacroExpansion, bool OwnsTokens,
bool IsReinject);
void EnterTokenStream(std::unique_ptr<Token[]> Toks, unsigned NumToks,
bool DisableMacroExpansion, bool IsReinject) {
EnterTokenStream(Toks.release(), NumToks, DisableMacroExpansion, true,
void EnterTokenStream(ArrayRef<Token> Toks, bool DisableMacroExpansion,
bool IsReinject) {
EnterTokenStream(, Toks.size(), DisableMacroExpansion, false,
/// Pop the current lexer/macro exp off the top of the lexer stack.
/// This should only be used in situations where the current state of the
/// top-of-stack lexer is known.
void RemoveTopOfLexerStack();
/// From the point that this method is called, and until
/// CommitBacktrackedTokens() or Backtrack() is called, the Preprocessor
/// keeps track of the lexed tokens so that a subsequent Backtrack() call will
/// make the Preprocessor re-lex the same tokens.
/// Nested backtracks are allowed, meaning that EnableBacktrackAtThisPos can
/// be called multiple times and CommitBacktrackedTokens/Backtrack calls will
/// be combined with the EnableBacktrackAtThisPos calls in reverse order.
/// NOTE: *DO NOT* forget to call either CommitBacktrackedTokens or Backtrack
/// at some point after EnableBacktrackAtThisPos. If you don't, caching of
/// tokens will continue indefinitely.
void EnableBacktrackAtThisPos();
/// Disable the last EnableBacktrackAtThisPos call.
void CommitBacktrackedTokens();
/// Make Preprocessor re-lex the tokens that were lexed since
/// EnableBacktrackAtThisPos() was previously called.
void Backtrack();
/// True if EnableBacktrackAtThisPos() was called and
/// caching of tokens is on.
bool isBacktrackEnabled() const { return !BacktrackPositions.empty(); }
/// Lex the next token for this preprocessor.
void Lex(Token &Result);
/// Lex a token, forming a header-name token if possible.
bool LexHeaderName(Token &Result, bool AllowMacroExpansion = true);
bool LexAfterModuleImport(Token &Result);
void CollectPpImportSuffix(SmallVectorImpl<Token> &Toks);
void makeModuleVisible(Module *M, SourceLocation Loc);
SourceLocation getModuleImportLoc(Module *M) const {
return CurSubmoduleState->VisibleModules.getImportLoc(M);
/// Lex a string literal, which may be the concatenation of multiple
/// string literals and may even come from macro expansion.
/// \returns true on success, false if a error diagnostic has been generated.
bool LexStringLiteral(Token &Result, std::string &String,
const char *DiagnosticTag, bool AllowMacroExpansion) {
if (AllowMacroExpansion)
return FinishLexStringLiteral(Result, String, DiagnosticTag,
/// Complete the lexing of a string literal where the first token has
/// already been lexed (see LexStringLiteral).
bool FinishLexStringLiteral(Token &Result, std::string &String,
const char *DiagnosticTag,
bool AllowMacroExpansion);
/// Lex a token. If it's a comment, keep lexing until we get
/// something not a comment.
/// This is useful in -E -C mode where comments would foul up preprocessor
/// directive handling.
void LexNonComment(Token &Result) {
while (Result.getKind() == tok::comment);
/// Just like Lex, but disables macro expansion of identifier tokens.
void LexUnexpandedToken(Token &Result) {
// Disable macro expansion.
bool OldVal = DisableMacroExpansion;
DisableMacroExpansion = true;
// Lex the token.
// Reenable it.
DisableMacroExpansion = OldVal;
/// Like LexNonComment, but this disables macro expansion of
/// identifier tokens.
void LexUnexpandedNonComment(Token &Result) {
while (Result.getKind() == tok::comment);
/// Parses a simple integer literal to get its numeric value. Floating
/// point literals and user defined literals are rejected. Used primarily to
/// handle pragmas that accept integer arguments.
bool parseSimpleIntegerLiteral(Token &Tok, uint64_t &Value);
/// Disables macro expansion everywhere except for preprocessor directives.
void SetMacroExpansionOnlyInDirectives() {
DisableMacroExpansion = true;
MacroExpansionInDirectivesOverride = true;
/// Peeks ahead N tokens and returns that token without consuming any
/// tokens.
/// LookAhead(0) returns the next token that would be returned by Lex(),
/// LookAhead(1) returns the token after it, etc. This returns normal
/// tokens after phase 5. As such, it is equivalent to using
/// 'Lex', not 'LexUnexpandedToken'.
const Token &LookAhead(unsigned N) {
assert(LexLevel == 0 && "cannot use lookahead while lexing");
if (CachedLexPos + N < CachedTokens.size())
return CachedTokens[CachedLexPos+N];
return PeekAhead(N+1);
/// When backtracking is enabled and tokens are cached,
/// this allows to revert a specific number of tokens.
/// Note that the number of tokens being reverted should be up to the last
/// backtrack position, not more.
void RevertCachedTokens(unsigned N) {
assert(isBacktrackEnabled() &&
"Should only be called when tokens are cached for backtracking");
assert(signed(CachedLexPos) - signed(N) >= signed(BacktrackPositions.back())
&& "Should revert tokens up to the last backtrack position, not more");
assert(signed(CachedLexPos) - signed(N) >= 0 &&
"Corrupted backtrack positions ?");
CachedLexPos -= N;
/// Enters a token in the token stream to be lexed next.
/// If BackTrack() is called afterwards, the token will remain at the
/// insertion point.
/// If \p IsReinject is true, resulting token will have Token::IsReinjected
/// flag set. See the flag documentation for details.
void EnterToken(const Token &Tok, bool IsReinject) {
if (LexLevel) {
// It's not correct in general to enter caching lex mode while in the
// middle of a nested lexing action.
auto TokCopy = std::make_unique<Token[]>(1);
TokCopy[0] = Tok;
EnterTokenStream(std::move(TokCopy), 1, true, IsReinject);
} else {
assert(IsReinject && "new tokens in the middle of cached stream");
CachedTokens.insert(CachedTokens.begin()+CachedLexPos, Tok);
/// We notify the Preprocessor that if it is caching tokens (because
/// backtrack is enabled) it should replace the most recent cached tokens
/// with the given annotation token. This function has no effect if
/// backtracking is not enabled.
/// Note that the use of this function is just for optimization, so that the
/// cached tokens doesn't get re-parsed and re-resolved after a backtrack is
/// invoked.
void AnnotateCachedTokens(const Token &Tok) {
assert(Tok.isAnnotation() && "Expected annotation token");
if (CachedLexPos != 0 && isBacktrackEnabled())
/// Get the location of the last cached token, suitable for setting the end
/// location of an annotation token.
SourceLocation getLastCachedTokenLocation() const {
assert(CachedLexPos != 0);
return CachedTokens[CachedLexPos-1].getLastLoc();
/// Whether \p Tok is the most recent token (`CachedLexPos - 1`) in
/// CachedTokens.
bool IsPreviousCachedToken(const Token &Tok) const;
/// Replace token in `CachedLexPos - 1` in CachedTokens by the tokens
/// in \p NewToks.
/// Useful when a token needs to be split in smaller ones and CachedTokens
/// most recent token must to be updated to reflect that.
void ReplacePreviousCachedToken(ArrayRef<Token> NewToks);
/// Replace the last token with an annotation token.
/// Like AnnotateCachedTokens(), this routine replaces an
/// already-parsed (and resolved) token with an annotation
/// token. However, this routine only replaces the last token with
/// the annotation token; it does not affect any other cached
/// tokens. This function has no effect if backtracking is not
/// enabled.
void ReplaceLastTokenWithAnnotation(const Token &Tok) {
assert(Tok.isAnnotation() && "Expected annotation token");
if (CachedLexPos != 0 && isBacktrackEnabled())
CachedTokens[CachedLexPos-1] = Tok;
/// Enter an annotation token into the token stream.
void EnterAnnotationToken(SourceRange Range, tok::TokenKind Kind,
void *AnnotationVal);
/// Determine whether it's possible for a future call to Lex to produce an
/// annotation token created by a previous call to EnterAnnotationToken.
bool mightHavePendingAnnotationTokens() {
return CurLexerKind != CLK_Lexer;
/// Update the current token to represent the provided
/// identifier, in order to cache an action performed by typo correction.
void TypoCorrectToken(const Token &Tok) {
assert(Tok.getIdentifierInfo() && "Expected identifier token");
if (CachedLexPos != 0 && isBacktrackEnabled())
CachedTokens[CachedLexPos-1] = Tok;
/// Recompute the current lexer kind based on the CurLexer/
/// CurTokenLexer pointers.
void recomputeCurLexerKind();
/// Returns true if incremental processing is enabled
bool isIncrementalProcessingEnabled() const {
return getLangOpts().IncrementalExtensions;
/// Enables the incremental processing
void enableIncrementalProcessing(bool value = true) {
// FIXME: Drop this interface.
const_cast<LangOptions &>(getLangOpts()).IncrementalExtensions = value;
/// Specify the point at which code-completion will be performed.
/// \param File the file in which code completion should occur. If
/// this file is included multiple times, code-completion will
/// perform completion the first time it is included. If NULL, this
/// function clears out the code-completion point.
/// \param Line the line at which code completion should occur
/// (1-based).
/// \param Column the column at which code completion should occur
/// (1-based).
/// \returns true if an error occurred, false otherwise.
bool SetCodeCompletionPoint(const FileEntry *File,
unsigned Line, unsigned Column);
/// Determine if we are performing code completion.
bool isCodeCompletionEnabled() const { return CodeCompletionFile != nullptr; }
/// Returns the location of the code-completion point.
/// Returns an invalid location if code-completion is not enabled or the file
/// containing the code-completion point has not been lexed yet.
SourceLocation getCodeCompletionLoc() const { return CodeCompletionLoc; }
/// Returns the start location of the file of code-completion point.
/// Returns an invalid location if code-completion is not enabled or the file
/// containing the code-completion point has not been lexed yet.
SourceLocation getCodeCompletionFileLoc() const {
return CodeCompletionFileLoc;
/// Returns true if code-completion is enabled and we have hit the
/// code-completion point.
bool isCodeCompletionReached() const { return CodeCompletionReached; }
/// Note that we hit the code-completion point.
void setCodeCompletionReached() {
assert(isCodeCompletionEnabled() && "Code-completion not enabled!");
CodeCompletionReached = true;
// Silence any diagnostics that occur after we hit the code-completion.
/// The location of the currently-active \#pragma clang
/// arc_cf_code_audited begin.
/// Returns an invalid location if there is no such pragma active.
std::pair<IdentifierInfo *, SourceLocation>
getPragmaARCCFCodeAuditedInfo() const {
return PragmaARCCFCodeAuditedInfo;
/// Set the location of the currently-active \#pragma clang
/// arc_cf_code_audited begin. An invalid location ends the pragma.
void setPragmaARCCFCodeAuditedInfo(IdentifierInfo *Ident,
SourceLocation Loc) {
PragmaARCCFCodeAuditedInfo = {Ident, Loc};
/// The location of the currently-active \#pragma clang
/// assume_nonnull begin.
/// Returns an invalid location if there is no such pragma active.
SourceLocation getPragmaAssumeNonNullLoc() const {
return PragmaAssumeNonNullLoc;
/// Set the location of the currently-active \#pragma clang
/// assume_nonnull begin. An invalid location ends the pragma.
void setPragmaAssumeNonNullLoc(SourceLocation Loc) {
PragmaAssumeNonNullLoc = Loc;
/// Get the location of the recorded unterminated \#pragma clang
/// assume_nonnull begin in the preamble, if one exists.
/// Returns an invalid location if the premable did not end with
/// such a pragma active or if there is no recorded preamble.
SourceLocation getPreambleRecordedPragmaAssumeNonNullLoc() const {
return PreambleRecordedPragmaAssumeNonNullLoc;
/// Record the location of the unterminated \#pragma clang
/// assume_nonnull begin in the preamble.
void setPreambleRecordedPragmaAssumeNonNullLoc(SourceLocation Loc) {
PreambleRecordedPragmaAssumeNonNullLoc = Loc;
/// Set the directory in which the main file should be considered
/// to have been found, if it is not a real file.
void setMainFileDir(const DirectoryEntry *Dir) {
MainFileDir = Dir;
/// Instruct the preprocessor to skip part of the main source file.
/// \param Bytes The number of bytes in the preamble to skip.
/// \param StartOfLine Whether skipping these bytes puts the lexer at the
/// start of a line.
void setSkipMainFilePreamble(unsigned Bytes, bool StartOfLine) {
SkipMainFilePreamble.first = Bytes;
SkipMainFilePreamble.second = StartOfLine;
/// Forwarding function for diagnostics. This emits a diagnostic at
/// the specified Token's location, translating the token's start
/// position in the current buffer into a SourcePosition object for rendering.
DiagnosticBuilder Diag(SourceLocation Loc, unsigned DiagID) const {
return Diags->Report(Loc, DiagID);
DiagnosticBuilder Diag(const Token &Tok, unsigned DiagID) const {
return Diags->Report(Tok.getLocation(), DiagID);
/// Return the 'spelling' of the token at the given
/// location; does not go up to the spelling location or down to the
/// expansion location.
/// \param buffer A buffer which will be used only if the token requires
/// "cleaning", e.g. if it contains trigraphs or escaped newlines
/// \param invalid If non-null, will be set \c true if an error occurs.
StringRef getSpelling(SourceLocation loc,
SmallVectorImpl<char> &buffer,
bool *invalid = nullptr) const {
return Lexer::getSpelling(loc, buffer, SourceMgr, LangOpts, invalid);
/// Return the 'spelling' of the Tok token.
/// The spelling of a token is the characters used to represent the token in
/// the source file after trigraph expansion and escaped-newline folding. In
/// particular, this wants to get the true, uncanonicalized, spelling of
/// things like digraphs, UCNs, etc.
/// \param Invalid If non-null, will be set \c true if an error occurs.
std::string getSpelling(const Token &Tok, bool *Invalid = nullptr) const {
return Lexer::getSpelling(Tok, SourceMgr, LangOpts, Invalid);
/// Get the spelling of a token into a preallocated buffer, instead
/// of as an std::string.
/// The caller is required to allocate enough space for the token, which is
/// guaranteed to be at least Tok.getLength() bytes long. The length of the
/// actual result is returned.
/// Note that this method may do two possible things: it may either fill in
/// the buffer specified with characters, or it may *change the input pointer*
/// to point to a constant buffer with the data already in it (avoiding a
/// copy). The caller is not allowed to modify the returned buffer pointer
/// if an internal buffer is returned.
unsigned getSpelling(const Token &Tok, const char *&Buffer,
bool *Invalid = nullptr) const {
return Lexer::getSpelling(Tok, Buffer, SourceMgr, LangOpts, Invalid);
/// 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 getSpelling(const Token &Tok,
SmallVectorImpl<char> &Buffer,
bool *Invalid = nullptr) const;
/// Relex the token at the specified location.
/// \returns true if there was a failure, false on success.
bool getRawToken(SourceLocation Loc, Token &Result,
bool IgnoreWhiteSpace = false) {
return Lexer::getRawToken(Loc, Result, SourceMgr, LangOpts, IgnoreWhiteSpace);
/// Given a Token \p Tok that is a numeric constant with length 1,
/// return the character.
getSpellingOfSingleCharacterNumericConstant(const Token &Tok,
bool *Invalid = nullptr) const {
assert( &&
Tok.getLength() == 1 && "Called on unsupported token");
assert(!Tok.needsCleaning() && "Token can't need cleaning with length 1");
// If the token is carrying a literal data pointer, just use it.
if (const char *D = Tok.getLiteralData())
return *D;
// Otherwise, fall back on getCharacterData, which is slower, but always
// works.
return *SourceMgr.getCharacterData(Tok.getLocation(), Invalid);
/// Retrieve the name of the immediate macro expansion.
/// This routine starts from a source location, and finds the name of the
/// macro responsible for its immediate expansion. It looks through any
/// intervening macro argument expansions to compute this. It returns a
/// StringRef that refers to the SourceManager-owned buffer of the source
/// where that macro name is spelled. Thus, the result shouldn't out-live
/// the SourceManager.
StringRef getImmediateMacroName(SourceLocation Loc) {
return Lexer::getImmediateMacroName(Loc, SourceMgr, getLangOpts());
/// Plop the specified string into a scratch buffer and set the
/// specified token's location and length to it.
/// If specified, the source location provides a location of the expansion
/// point of the token.
void CreateString(StringRef Str, Token &Tok,
SourceLocation ExpansionLocStart = SourceLocation(),
SourceLocation ExpansionLocEnd = SourceLocation());
/// Split the first Length characters out of the token starting at TokLoc
/// and return a location pointing to the split token. Re-lexing from the
/// split token will return the split token rather than the original.
SourceLocation SplitToken(SourceLocation TokLoc, unsigned Length);
/// Computes the source location just past the end of the
/// token at this source location.
/// This routine can be used to produce a source location that
/// points just past the end of the token referenced by \p Loc, and
/// is generally used when a diagnostic needs to point just after a
/// token where it expected something different that it received. If
/// the returned source location would not be meaningful (e.g., if
/// it points into a macro), this routine returns an invalid
/// source location.
/// \param Offset an offset from the end of the token, where the source
/// location should refer to. The default offset (0) produces a source
/// location pointing just past the end of the token; an offset of 1 produces
/// a source location pointing to the last character in the token, etc.
SourceLocation getLocForEndOfToken(SourceLocation Loc, unsigned Offset = 0) {
return Lexer::getLocForEndOfToken(Loc, Offset, SourceMgr, LangOpts);
/// Returns true if the given MacroID location points at the first
/// token of the macro expansion.
/// \param MacroBegin If non-null and function returns true, it is set to
/// begin location of the macro.
bool isAtStartOfMacroExpansion(SourceLocation loc,
SourceLocation *MacroBegin = nullptr) const {
return Lexer::isAtStartOfMacroExpansion(loc, SourceMgr, LangOpts,
/// Returns true if the given MacroID location points at the last
/// token of the macro expansion.
/// \param MacroEnd If non-null and function returns true, it is set to
/// end location of the macro.
bool isAtEndOfMacroExpansion(SourceLocation loc,
SourceLocation *MacroEnd = nullptr) const {
return Lexer::isAtEndOfMacroExpansion(loc, SourceMgr, LangOpts, MacroEnd);
/// Print the token to stderr, used for debugging.
void DumpToken(const Token &Tok, bool DumpFlags = false) const;
void DumpLocation(SourceLocation Loc) const;
void DumpMacro(const MacroInfo &MI) const;
void dumpMacroInfo(const IdentifierInfo *II);
/// Given a location that specifies the start of a
/// token, return a new location that specifies a character within the token.
SourceLocation AdvanceToTokenCharacter(SourceLocation TokStart,
unsigned Char) const {
return Lexer::AdvanceToTokenCharacter(TokStart, Char, SourceMgr, LangOpts);
/// Increment the counters for the number of token paste operations
/// performed.
/// If fast was specified, this is a 'fast paste' case we handled.
void IncrementPasteCounter(bool isFast) {
if (isFast)
void PrintStats();
size_t getTotalMemory() const;
/// When the macro expander pastes together a comment (/##/) in Microsoft
/// mode, this method handles updating the current state, returning the
/// token on the next source line.
void HandleMicrosoftCommentPaste(Token &Tok);
// Preprocessor callback methods. These are invoked by a lexer as various
// directives and events are found.
/// 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 *LookUpIdentifierInfo(Token &Identifier) const;
llvm::DenseMap<IdentifierInfo*,unsigned> PoisonReasons;
/// Specifies the reason for poisoning an identifier.
/// If that identifier is accessed while poisoned, then this reason will be
/// used instead of the default "poisoned" diagnostic.
void SetPoisonReason(IdentifierInfo *II, unsigned DiagID);
/// Display reason for poisoned identifier.
void HandlePoisonedIdentifier(Token & Identifier);
void MaybeHandlePoisonedIdentifier(Token & Identifier) {
if(IdentifierInfo * II = Identifier.getIdentifierInfo()) {
if(II->isPoisoned()) {
/// Identifiers used for SEH handling in Borland. These are only
/// allowed in particular circumstances
// __except block
IdentifierInfo *Ident__exception_code,
// __except filter expression
IdentifierInfo *Ident__exception_info,
// __finally
IdentifierInfo *Ident__abnormal_termination,
const char *getCurLexerEndPos();
void diagnoseMissingHeaderInUmbrellaDir(const Module &Mod);
void PoisonSEHIdentifiers(bool Poison = true); // Borland
/// Callback invoked when the lexer reads an identifier and has
/// filled in the tokens IdentifierInfo member.
/// This callback potentially macro expands it or turns it into a named
/// token (like 'for').
/// \returns true if we actually computed a token, false if we need to
/// lex again.
bool HandleIdentifier(Token &Identifier);
/// Callback invoked when the lexer hits the end of the current file.
/// This either returns the EOF token and returns true, or
/// pops a level off the include stack and returns false, at which point the
/// client should call lex again.
bool HandleEndOfFile(Token &Result, bool isEndOfMacro = false);
/// Callback invoked when the current TokenLexer hits the end of its
/// token stream.
bool HandleEndOfTokenLexer(Token &Result);
/// Callback invoked when the lexer sees a # token at the start of a
/// line.
/// This consumes the directive, modifies the lexer/preprocessor state, and
/// advances the lexer(s) so that the next token read is the correct one.
void HandleDirective(Token &Result);
/// Ensure that the next token is a tok::eod token.
/// If not, emit a diagnostic and consume up until the eod.
/// If \p EnableMacros is true, then we consider macros that expand to zero
/// tokens as being ok.
/// \return The location of the end of the directive (the terminating
/// newline).
SourceLocation CheckEndOfDirective(const char *DirType,
bool EnableMacros = false);
/// Read and discard all tokens remaining on the current line until
/// the tok::eod token is found. Returns the range of the skipped tokens.
SourceRange DiscardUntilEndOfDirective();
/// Returns true if the preprocessor has seen a use of
/// __DATE__ or __TIME__ in the file so far.
bool SawDateOrTime() const {
return DATELoc != SourceLocation() || TIMELoc != SourceLocation();
unsigned getCounterValue() const { return CounterValue; }
void setCounterValue(unsigned V) { CounterValue = V; }
LangOptions::FPEvalMethodKind getCurrentFPEvalMethod() const {
assert(CurrentFPEvalMethod != LangOptions::FEM_UnsetOnCommandLine &&
"FPEvalMethod should be set either from command line or from the "
"target info");
return CurrentFPEvalMethod;
LangOptions::FPEvalMethodKind getTUFPEvalMethod() const {
return TUFPEvalMethod;
SourceLocation getLastFPEvalPragmaLocation() const {
return LastFPEvalPragmaLocation;
LangOptions::FPEvalMethodKind getLastFPEvalMethod() const {
return LastFPEvalMethod;
void setLastFPEvalMethod(LangOptions::FPEvalMethodKind Val) {
LastFPEvalMethod = Val;
void setCurrentFPEvalMethod(SourceLocation PragmaLoc,
LangOptions::FPEvalMethodKind Val) {
assert(Val != LangOptions::FEM_UnsetOnCommandLine &&
"FPEvalMethod should never be set to FEM_UnsetOnCommandLine");
// This is the location of the '#pragma float_control" where the
// execution state is modifed.
LastFPEvalPragmaLocation = PragmaLoc;
CurrentFPEvalMethod = Val;
TUFPEvalMethod = Val;
void setTUFPEvalMethod(LangOptions::FPEvalMethodKind Val) {
assert(Val != LangOptions::FEM_UnsetOnCommandLine &&
"TUPEvalMethod should never be set to FEM_UnsetOnCommandLine");
TUFPEvalMethod = Val;
/// Retrieves the module that we're currently building, if any.
Module *getCurrentModule();
/// Retrieves the module whose implementation we're current compiling, if any.
Module *getCurrentModuleImplementation();
/// If we are preprocessing a named module.
bool isInNamedModule() const { return ModuleDeclState.isNamedModule(); }
/// If we are proprocessing a named interface unit.
/// Note that a module implementation partition is not considered as an
/// named interface unit here although it is importable
/// to ease the parsing.
bool isInNamedInterfaceUnit() const {
return ModuleDeclState.isNamedInterface();
/// Get the named module name we're preprocessing.
/// Requires we're preprocessing a named module.
StringRef getNamedModuleName() const { return ModuleDeclState.getName(); }
/// If we are implementing an implementation module unit.
/// Note that the module implementation partition is not considered as an
/// implementation unit.
bool isInImplementationUnit() const {
return ModuleDeclState.isImplementationUnit();
/// If we're importing a standard C++20 Named Modules.
bool isInImportingCXXNamedModules() const {
// NamedModuleImportPath will be non-empty only if we're importing
// Standard C++ named modules.
return !NamedModuleImportPath.empty() && getLangOpts().CPlusPlusModules &&
/// Allocate a new MacroInfo object with the provided SourceLocation.
MacroInfo *AllocateMacroInfo(SourceLocation L);
/// Turn the specified lexer token into a fully checked and spelled
/// filename, e.g. as an operand of \#include.
/// The caller is expected to provide a buffer that is large enough to hold
/// the spelling of the filename, but is also expected to handle the case
/// when this method decides to use a different buffer.
/// \returns true if the input filename was in <>'s or false if it was
/// in ""'s.
bool GetIncludeFilenameSpelling(SourceLocation Loc,StringRef &Buffer);
/// Given a "foo" or \<foo> reference, look up the indicated file.
/// Returns std::nullopt on failure. \p isAngled indicates whether the file
/// reference is for system \#include's or not (i.e. using <> instead of "").
LookupFile(SourceLocation FilenameLoc, StringRef Filename, bool isAngled,
ConstSearchDirIterator FromDir, const FileEntry *FromFile,
ConstSearchDirIterator *CurDir, SmallVectorImpl<char> *SearchPath,
SmallVectorImpl<char> *RelativePath,
ModuleMap::KnownHeader *SuggestedModule, bool *IsMapped,
bool *IsFrameworkFound, bool SkipCache = false,
bool OpenFile = true, bool CacheFailures = true);
/// Return true if we're in the top-level file, not in a \#include.
bool isInPrimaryFile() const;
/// Lex an on-off-switch (C99 6.10.6p2) and verify that it is
/// followed by EOD. Return true if the token is not a valid on-off-switch.
bool LexOnOffSwitch(tok::OnOffSwitch &Result);
bool CheckMacroName(Token &MacroNameTok, MacroUse isDefineUndef,
bool *ShadowFlag = nullptr);
void EnterSubmodule(Module *M, SourceLocation ImportLoc, bool ForPragma);
Module *LeaveSubmodule(bool ForPragma);
friend void TokenLexer::ExpandFunctionArguments();
void PushIncludeMacroStack() {
assert(CurLexerKind != CLK_CachingLexer && "cannot push a caching lexer");
IncludeMacroStack.emplace_back(CurLexerKind, CurLexerSubmodule,
std::move(CurLexer), CurPPLexer,
std::move(CurTokenLexer), CurDirLookup);
CurPPLexer = nullptr;
void PopIncludeMacroStack() {
CurLexer = std::move(IncludeMacroStack.back().TheLexer);
CurPPLexer = IncludeMacroStack.back().ThePPLexer;
CurTokenLexer = std::move(IncludeMacroStack.back().TheTokenLexer);
CurDirLookup = IncludeMacroStack.back().TheDirLookup;
CurLexerSubmodule = IncludeMacroStack.back().TheSubmodule;
CurLexerKind = IncludeMacroStack.back().CurLexerKind;
void PropagateLineStartLeadingSpaceInfo(Token &Result);
/// Determine whether we need to create module macros for #defines in the
/// current context.
bool needModuleMacros() const;
/// Update the set of active module macros and ambiguity flag for a module
/// macro name.
void updateModuleMacroInfo(const IdentifierInfo *II, ModuleMacroInfo &Info);
DefMacroDirective *AllocateDefMacroDirective(MacroInfo *MI,
SourceLocation Loc);
UndefMacroDirective *AllocateUndefMacroDirective(SourceLocation UndefLoc);
VisibilityMacroDirective *AllocateVisibilityMacroDirective(SourceLocation Loc,
bool isPublic);
/// Lex and validate a macro name, which occurs after a
/// \#define or \#undef.
/// \param MacroNameTok Token that represents the name defined or undefined.
/// \param IsDefineUndef Kind if preprocessor directive.
/// \param ShadowFlag Points to flag that is set if macro name shadows
/// a keyword.
/// This emits a diagnostic, sets the token kind to eod,
/// and discards the rest of the macro line if the macro name is invalid.
void ReadMacroName(Token &MacroNameTok, MacroUse IsDefineUndef = MU_Other,
bool *ShadowFlag = nullptr);
/// ReadOptionalMacroParameterListAndBody - This consumes all (i.e. the
/// entire line) of the macro's tokens and adds them to MacroInfo, and while
/// doing so performs certain validity checks including (but not limited to):
/// - # (stringization) is followed by a macro parameter
/// \param MacroNameTok - Token that represents the macro name
/// \param ImmediatelyAfterHeaderGuard - Macro follows an #ifdef header guard
/// Either returns a pointer to a MacroInfo object OR emits a diagnostic and
/// returns a nullptr if an invalid sequence of tokens is encountered.
MacroInfo *ReadOptionalMacroParameterListAndBody(
const Token &MacroNameTok, bool ImmediatelyAfterHeaderGuard);
/// The ( starting an argument list of a macro definition has just been read.
/// Lex the rest of the parameters and the closing ), updating \p MI with
/// what we learn and saving in \p LastTok the last token read.
/// Return true if an error occurs parsing the arg list.
bool ReadMacroParameterList(MacroInfo *MI, Token& LastTok);
/// Provide a suggestion for a typoed directive. If there is no typo, then
/// just skip suggesting.
/// \param Tok - Token that represents the directive
/// \param Directive - String reference for the directive name
void SuggestTypoedDirective(const Token &Tok, StringRef Directive) const;
/// We just read a \#if or related directive and decided that the
/// subsequent tokens are in the \#if'd out portion of the
/// file. Lex the rest of the file, until we see an \#endif. If \p
/// FoundNonSkipPortion is true, then we have already emitted code for part of
/// this \#if directive, so \#else/\#elif blocks should never be entered. If
/// \p FoundElse is false, then \#else directives are ok, if not, then we have
/// already seen one so a \#else directive is a duplicate. When this returns,
/// the caller can lex the first valid token.
void SkipExcludedConditionalBlock(SourceLocation HashTokenLoc,
SourceLocation IfTokenLoc,
bool FoundNonSkipPortion, bool FoundElse,
SourceLocation ElseLoc = SourceLocation());
/// Information about the result for evaluating an expression for a
/// preprocessor directive.
struct DirectiveEvalResult {
/// Whether the expression was evaluated as true or not.
bool Conditional;
/// True if the expression contained identifiers that were undefined.
bool IncludedUndefinedIds;
/// The source range for the expression.
SourceRange ExprRange;
/// Evaluate an integer constant expression that may occur after a
/// \#if or \#elif directive and return a \p DirectiveEvalResult object.
/// If the expression is equivalent to "!defined(X)" return X in IfNDefMacro.
DirectiveEvalResult EvaluateDirectiveExpression(IdentifierInfo *&IfNDefMacro);
/// Process a '__has_include("path")' expression.
/// Returns true if successful.
bool EvaluateHasInclude(Token &Tok, IdentifierInfo *II);
/// Process '__has_include_next("path")' expression.
/// Returns true if successful.
bool EvaluateHasIncludeNext(Token &Tok, IdentifierInfo *II);
/// Get the directory and file from which to start \#include_next lookup.
std::pair<ConstSearchDirIterator, const FileEntry *>
getIncludeNextStart(const Token &IncludeNextTok) const;
/// Install the standard preprocessor pragmas:
/// \#pragma GCC poison/system_header/dependency and \#pragma once.
void RegisterBuiltinPragmas();
/// Register builtin macros such as __LINE__ with the identifier table.
void RegisterBuiltinMacros();
/// If an identifier token is read that is to be expanded as a macro, handle
/// it and return the next token as 'Tok'. If we lexed a token, return true;
/// otherwise the caller should lex again.
bool HandleMacroExpandedIdentifier(Token &Identifier, const MacroDefinition &MD);
/// Cache macro expanded tokens for TokenLexers.
/// Works like a stack; a TokenLexer adds the macro expanded tokens that is
/// going to lex in the cache and when it finishes the tokens are removed
/// from the end of the cache.
Token *cacheMacroExpandedTokens(TokenLexer *tokLexer,
ArrayRef<Token> tokens);
void removeCachedMacroExpandedTokensOfLastLexer();
/// Determine whether the next preprocessor token to be
/// lexed is a '('. If so, consume the token and return true, if not, this
/// method should have no observable side-effect on the lexed tokens.
bool isNextPPTokenLParen();
/// After reading "MACRO(", this method is invoked to read all of the formal
/// arguments specified for the macro invocation. Returns null on error.
MacroArgs *ReadMacroCallArgumentList(Token &MacroName, MacroInfo *MI,
SourceLocation &MacroEnd);
/// If an identifier token is read that is to be expanded
/// as a builtin macro, handle it and return the next token as 'Tok'.
void ExpandBuiltinMacro(Token &Tok);
/// Read a \c _Pragma directive, slice it up, process it, then
/// return the first token after the directive.
/// This assumes that the \c _Pragma token has just been read into \p Tok.
void Handle_Pragma(Token &Tok);
/// Like Handle_Pragma except the pragma text is not enclosed within
/// a string literal.
void HandleMicrosoft__pragma(Token &Tok);
/// Add a lexer to the top of the include stack and
/// start lexing tokens from it instead of the current buffer.
void EnterSourceFileWithLexer(Lexer *TheLexer, ConstSearchDirIterator Dir);
/// Set the FileID for the preprocessor predefines.
void setPredefinesFileID(FileID FID) {
assert(PredefinesFileID.isInvalid() && "PredefinesFileID already set!");
PredefinesFileID = FID;
/// Set the FileID for the PCH through header.
void setPCHThroughHeaderFileID(FileID FID);
/// Returns true if we are lexing from a file and not a
/// pragma or a macro.
static bool IsFileLexer(const Lexer* L, const PreprocessorLexer* P) {
return L ? !L->isPragmaLexer() : P != nullptr;
static bool IsFileLexer(const IncludeStackInfo& I) {
return IsFileLexer(I.TheLexer.get(), I.ThePPLexer);
bool IsFileLexer() const {
return IsFileLexer(CurLexer.get(), CurPPLexer);
// Caching stuff.
void CachingLex(Token &Result);
bool InCachingLexMode() const {
// If the Lexer pointers are 0 and IncludeMacroStack is empty, it means
// that we are past EOF, not that we are in CachingLex mode.
return !CurPPLexer && !CurTokenLexer && !IncludeMacroStack.empty();
void EnterCachingLexMode();
void EnterCachingLexModeUnchecked();
void ExitCachingLexMode() {
if (InCachingLexMode())
const Token &PeekAhead(unsigned N);
void AnnotatePreviousCachedTokens(const Token &Tok);
/// Handle*Directive - implement the various preprocessor directives. These
/// should side-effect the current preprocessor object so that the next call
/// to Lex() will return the appropriate token next.
void HandleLineDirective();
void HandleDigitDirective(Token &Tok);
void HandleUserDiagnosticDirective(Token &Tok, bool isWarning);
void HandleIdentSCCSDirective(Token &Tok);
void HandleMacroPublicDirective(Token &Tok);
void HandleMacroPrivateDirective();
/// An additional notification that can be produced by a header inclusion or
/// import to tell the parser what happened.
struct ImportAction {
enum ActionKind {
} Kind;
Module *ModuleForHeader = nullptr;
ImportAction(ActionKind AK, Module *Mod = nullptr)
: Kind(AK), ModuleForHeader(Mod) {
assert((AK == None || Mod || AK == Failure) &&
"no module for module action");
OptionalFileEntryRef LookupHeaderIncludeOrImport(
ConstSearchDirIterator *CurDir, StringRef &Filename,
SourceLocation FilenameLoc, CharSourceRange FilenameRange,
const Token &FilenameTok, bool &IsFrameworkFound, bool IsImportDecl,
bool &IsMapped, ConstSearchDirIterator LookupFrom,
const FileEntry *LookupFromFile, StringRef &LookupFilename,
SmallVectorImpl<char> &RelativePath, SmallVectorImpl<char> &SearchPath,
ModuleMap::KnownHeader &SuggestedModule, bool isAngled);
// File inclusion.
void HandleIncludeDirective(SourceLocation HashLoc, Token &Tok,
ConstSearchDirIterator LookupFrom = nullptr,
const FileEntry *LookupFromFile = nullptr);
HandleHeaderIncludeOrImport(SourceLocation HashLoc, Token &IncludeTok,
Token &FilenameTok, SourceLocation EndLoc,
ConstSearchDirIterator LookupFrom = nullptr,
const FileEntry *LookupFromFile = nullptr);
void HandleIncludeNextDirective(SourceLocation HashLoc, Token &Tok);
void HandleIncludeMacrosDirective(SourceLocation HashLoc, Token &Tok);
void HandleImportDirective(SourceLocation HashLoc, Token &Tok);
void HandleMicrosoftImportDirective(Token &Tok);
/// Check that the given module is available, producing a diagnostic if not.
/// \return \c true if the check failed (because the module is not available).
/// \c false if the module appears to be usable.
static bool checkModuleIsAvailable(const LangOptions &LangOpts,
const TargetInfo &TargetInfo,
DiagnosticsEngine &Diags, Module *M);
// Module inclusion testing.
/// Find the module that owns the source or header file that
/// \p Loc points to. If the location is in a file that was included
/// into a module, or is outside any module, returns nullptr.
Module *getModuleForLocation(SourceLocation Loc, bool AllowTextual);
/// We want to produce a diagnostic at location IncLoc concerning an
/// unreachable effect at location MLoc (eg, where a desired entity was
/// declared or defined). Determine whether the right way to make MLoc
/// reachable is by #include, and if so, what header should be included.
/// This is not necessarily fast, and might load unexpected module maps, so
/// should only be called by code that intends to produce an error.
/// \param IncLoc The location at which the missing effect was detected.
/// \param MLoc A location within an unimported module at which the desired
/// effect occurred.
/// \return A file that can be #included to provide the desired effect. Null
/// if no such file could be determined or if a #include is not
/// appropriate (eg, if a module should be imported instead).
const FileEntry *getHeaderToIncludeForDiagnostics(SourceLocation IncLoc,
SourceLocation MLoc);
bool isRecordingPreamble() const {
return PreambleConditionalStack.isRecording();
bool hasRecordedPreamble() const {
return PreambleConditionalStack.hasRecordedPreamble();
ArrayRef<PPConditionalInfo> getPreambleConditionalStack() const {
return PreambleConditionalStack.getStack();
void setRecordedPreambleConditionalStack(ArrayRef<PPConditionalInfo> s) {
void setReplayablePreambleConditionalStack(
ArrayRef<PPConditionalInfo> s, std::optional<PreambleSkipInfo> SkipInfo) {
PreambleConditionalStack.SkipInfo = SkipInfo;
std::optional<PreambleSkipInfo> getPreambleSkipInfo() const {
return PreambleConditionalStack.SkipInfo;
/// After processing predefined file, initialize the conditional stack from
/// the preamble.
void replayPreambleConditionalStack();
// Macro handling.
void HandleDefineDirective(Token &Tok, bool ImmediatelyAfterHeaderGuard);
void HandleUndefDirective();
// Conditional Inclusion.
void HandleIfdefDirective(Token &Result, const Token &HashToken,
bool isIfndef, bool ReadAnyTokensBeforeDirective);
void HandleIfDirective(Token &IfToken, const Token &HashToken,
bool ReadAnyTokensBeforeDirective);
void HandleEndifDirective(Token &EndifToken);
void HandleElseDirective(Token &Result, const Token &HashToken);
void HandleElifFamilyDirective(Token &ElifToken, const Token &HashToken,
tok::PPKeywordKind Kind);
// Pragmas.
void HandlePragmaDirective(PragmaIntroducer Introducer);
void HandlePragmaOnce(Token &OnceTok);
void HandlePragmaMark(Token &MarkTok);
void HandlePragmaPoison();
void HandlePragmaSystemHeader(Token &SysHeaderTok);
void HandlePragmaDependency(Token &DependencyTok);
void HandlePragmaPushMacro(Token &Tok);
void HandlePragmaPopMacro(Token &Tok);
void HandlePragmaIncludeAlias(Token &Tok);
void HandlePragmaModuleBuild(Token &Tok);
void HandlePragmaHdrstop(Token &Tok);
IdentifierInfo *ParsePragmaPushOrPopMacro(Token &Tok);
// Return true and store the first token only if any CommentHandler
// has inserted some tokens and getCommentRetentionState() is false.
bool HandleComment(Token &result, SourceRange Comment);
/// A macro is used, update information about macros that need unused
/// warnings.
void markMacroAsUsed(MacroInfo *MI);
void addMacroDeprecationMsg(const IdentifierInfo *II, std::string Msg,
SourceLocation AnnotationLoc) {
auto Annotations = AnnotationInfos.find(II);
if (Annotations == AnnotationInfos.end())
MacroAnnotations::makeDeprecation(AnnotationLoc, std::move(Msg))));
Annotations->second.DeprecationInfo =
MacroAnnotationInfo{AnnotationLoc, std::move(Msg)};
void addRestrictExpansionMsg(const IdentifierInfo *II, std::string Msg,
SourceLocation AnnotationLoc) {
auto Annotations = AnnotationInfos.find(II);
if (Annotations == AnnotationInfos.end())
std::make_pair(II, MacroAnnotations::makeRestrictExpansion(
AnnotationLoc, std::move(Msg))));
Annotations->second.RestrictExpansionInfo =
MacroAnnotationInfo{AnnotationLoc, std::move(Msg)};
void addFinalLoc(const IdentifierInfo *II, SourceLocation AnnotationLoc) {
auto Annotations = AnnotationInfos.find(II);
if (Annotations == AnnotationInfos.end())
std::make_pair(II, MacroAnnotations::makeFinal(AnnotationLoc)));
Annotations->second.FinalAnnotationLoc = AnnotationLoc;
const MacroAnnotations &getMacroAnnotations(const IdentifierInfo *II) const {
return AnnotationInfos.find(II)->second;
void emitMacroExpansionWarnings(const Token &Identifier) const {
if (Identifier.getIdentifierInfo()->isDeprecatedMacro())
if (Identifier.getIdentifierInfo()->isRestrictExpansion() &&
static void processPathForFileMacro(SmallVectorImpl<char> &Path,
const LangOptions &LangOpts,
const TargetInfo &TI);
void emitMacroDeprecationWarning(const Token &Identifier) const;
void emitRestrictExpansionWarning(const Token &Identifier) const;
void emitFinalMacroWarning(const Token &Identifier, bool IsUndef) const;
/// Abstract base class that describes a handler that will receive
/// source ranges for each of the comments encountered in the source file.
class CommentHandler {
virtual ~CommentHandler();
// The handler shall return true if it has pushed any tokens
// to be read using e.g. EnterToken or EnterTokenStream.
virtual bool HandleComment(Preprocessor &PP, SourceRange Comment) = 0;
/// Abstract base class that describes a handler that will receive
/// source ranges for empty lines encountered in the source file.
class EmptylineHandler {
virtual ~EmptylineHandler();
// The handler handles empty lines.
virtual void HandleEmptyline(SourceRange Range) = 0;
/// Registry of pragma handlers added by plugins
using PragmaHandlerRegistry = llvm::Registry<PragmaHandler>;
} // namespace clang