202 lines · cpp
1//===--- ParseAST.cpp - Provide the clang::ParseAST method ----------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8//9// This file implements the clang::ParseAST method.10//11//===----------------------------------------------------------------------===//12 13#include "clang/Parse/ParseAST.h"14#include "clang/AST/ASTConsumer.h"15#include "clang/AST/ASTContext.h"16#include "clang/AST/ExternalASTSource.h"17#include "clang/AST/Stmt.h"18#include "clang/Parse/Parser.h"19#include "clang/Sema/CodeCompleteConsumer.h"20#include "clang/Sema/EnterExpressionEvaluationContext.h"21#include "clang/Sema/Sema.h"22#include "clang/Sema/SemaConsumer.h"23#include "clang/Sema/TemplateInstCallback.h"24#include "llvm/Support/CrashRecoveryContext.h"25#include "llvm/Support/TimeProfiler.h"26#include <cstdio>27#include <memory>28 29using namespace clang;30 31namespace {32 33/// Resets LLVM's pretty stack state so that stack traces are printed correctly34/// when there are nested CrashRecoveryContexts and the inner one recovers from35/// a crash.36class ResetStackCleanup37 : public llvm::CrashRecoveryContextCleanupBase<ResetStackCleanup,38 const void> {39public:40 ResetStackCleanup(llvm::CrashRecoveryContext *Context, const void *Top)41 : llvm::CrashRecoveryContextCleanupBase<ResetStackCleanup, const void>(42 Context, Top) {}43 void recoverResources() override {44 llvm::RestorePrettyStackState(resource);45 }46};47 48/// If a crash happens while the parser is active, an entry is printed for it.49class PrettyStackTraceParserEntry : public llvm::PrettyStackTraceEntry {50 const Parser &P;51public:52 PrettyStackTraceParserEntry(const Parser &p) : P(p) {}53 void print(raw_ostream &OS) const override;54};55 56/// If a crash happens while the parser is active, print out a line indicating57/// what the current token is.58void PrettyStackTraceParserEntry::print(raw_ostream &OS) const {59 const Token &Tok = P.getCurToken();60 if (Tok.is(tok::eof)) {61 OS << "<eof> parser at end of file\n";62 return;63 }64 65 if (Tok.getLocation().isInvalid()) {66 OS << "<unknown> parser at unknown location\n";67 return;68 }69 70 const Preprocessor &PP = P.getPreprocessor();71 Tok.getLocation().print(OS, PP.getSourceManager());72 if (Tok.isAnnotation()) {73 OS << ": at annotation token\n";74 } else {75 // Do the equivalent of PP.getSpelling(Tok) except for the parts that would76 // allocate memory.77 bool Invalid = false;78 const SourceManager &SM = P.getPreprocessor().getSourceManager();79 unsigned Length = Tok.getLength();80 const char *Spelling = SM.getCharacterData(Tok.getLocation(), &Invalid);81 if (Invalid) {82 OS << ": unknown current parser token\n";83 return;84 }85 OS << ": current parser token '" << StringRef(Spelling, Length) << "'\n";86 }87}88 89} // namespace90 91//===----------------------------------------------------------------------===//92// Public interface to the file93//===----------------------------------------------------------------------===//94 95/// ParseAST - Parse the entire file specified, notifying the ASTConsumer as96/// the file is parsed. This inserts the parsed decls into the translation unit97/// held by Ctx.98///99void clang::ParseAST(Preprocessor &PP, ASTConsumer *Consumer,100 ASTContext &Ctx, bool PrintStats,101 TranslationUnitKind TUKind,102 CodeCompleteConsumer *CompletionConsumer,103 bool SkipFunctionBodies) {104 105 std::unique_ptr<Sema> S(106 new Sema(PP, Ctx, *Consumer, TUKind, CompletionConsumer));107 108 // Recover resources if we crash before exiting this method.109 llvm::CrashRecoveryContextCleanupRegistrar<Sema> CleanupSema(S.get());110 111 ParseAST(*S, PrintStats, SkipFunctionBodies);112}113 114void clang::ParseAST(Sema &S, bool PrintStats, bool SkipFunctionBodies) {115 // Collect global stats on Decls/Stmts (until we have a module streamer).116 if (PrintStats) {117 Decl::EnableStatistics();118 Stmt::EnableStatistics();119 }120 121 // Also turn on collection of stats inside of the Sema object.122 bool OldCollectStats = PrintStats;123 std::swap(OldCollectStats, S.CollectStats);124 125 // Initialize the template instantiation observer chain.126 // FIXME: See note on "finalize" below.127 initialize(S.TemplateInstCallbacks, S);128 129 ASTConsumer *Consumer = &S.getASTConsumer();130 131 std::unique_ptr<Parser> ParseOP(132 new Parser(S.getPreprocessor(), S, SkipFunctionBodies));133 Parser &P = *ParseOP;134 135 llvm::CrashRecoveryContextCleanupRegistrar<const void, ResetStackCleanup>136 CleanupPrettyStack(llvm::SavePrettyStackState());137 PrettyStackTraceParserEntry CrashInfo(P);138 139 // Recover resources if we crash before exiting this method.140 llvm::CrashRecoveryContextCleanupRegistrar<Parser>141 CleanupParser(ParseOP.get());142 143 S.getPreprocessor().EnterMainSourceFile();144 ExternalASTSource *External = S.getASTContext().getExternalSource();145 if (External)146 External->StartTranslationUnit(Consumer);147 148 // If a PCH through header is specified that does not have an include in149 // the source, or a PCH is being created with #pragma hdrstop with nothing150 // after the pragma, there won't be any tokens or a Lexer.151 bool HaveLexer = S.getPreprocessor().getCurrentLexer();152 153 if (HaveLexer) {154 llvm::TimeTraceScope TimeScope("Frontend", [&]() {155 llvm::TimeTraceMetadata M;156 if (llvm::isTimeTraceVerbose()) {157 const SourceManager &SM = S.getSourceManager();158 if (const auto *FE = SM.getFileEntryForID(SM.getMainFileID()))159 M.File = FE->tryGetRealPathName();160 }161 return M;162 });163 P.Initialize();164 Parser::DeclGroupPtrTy ADecl;165 Sema::ModuleImportState ImportState;166 EnterExpressionEvaluationContext PotentiallyEvaluated(167 S, Sema::ExpressionEvaluationContext::PotentiallyEvaluated);168 169 for (bool AtEOF = P.ParseFirstTopLevelDecl(ADecl, ImportState); !AtEOF;170 AtEOF = P.ParseTopLevelDecl(ADecl, ImportState)) {171 // If we got a null return and something *was* parsed, ignore it. This172 // is due to a top-level semicolon, an action override, or a parse error173 // skipping something.174 if (ADecl && !Consumer->HandleTopLevelDecl(ADecl.get()))175 return;176 }177 }178 179 // Process any TopLevelDecls generated by #pragma weak.180 for (Decl *D : S.WeakTopLevelDecls())181 Consumer->HandleTopLevelDecl(DeclGroupRef(D));182 183 Consumer->HandleTranslationUnit(S.getASTContext());184 185 // Finalize the template instantiation observer chain.186 // FIXME: This (and init.) should be done in the Sema class, but because187 // Sema does not have a reliable "Finalize" function (it has a188 // destructor, but it is not guaranteed to be called ("-disable-free")).189 // So, do the initialization above and do the finalization here:190 finalize(S.TemplateInstCallbacks, S);191 192 std::swap(OldCollectStats, S.CollectStats);193 if (PrintStats) {194 llvm::errs() << "\nSTATISTICS:\n";195 if (HaveLexer) P.getActions().PrintStats();196 S.getASTContext().PrintStats();197 Decl::PrintStats();198 Stmt::PrintStats();199 Consumer->PrintStats();200 }201}202