clang 17.0.0git
ParseAST.cpp
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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-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file implements the clang::ParseAST method.
10//
11//===----------------------------------------------------------------------===//
12
17#include "clang/AST/Stmt.h"
19#include "clang/Parse/Parser.h"
21#include "clang/Sema/Sema.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 correctly
34/// when there are nested CrashRecoveryContexts and the inner one recovers from
35/// a crash.
36class ResetStackCleanup
37 : 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 indicating
57/// 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();
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 would
76 // 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} // namespace
90
91//===----------------------------------------------------------------------===//
92// Public interface to the file
93//===----------------------------------------------------------------------===//
94
95/// ParseAST - Parse the entire file specified, notifying the ASTConsumer as
96/// the file is parsed. This inserts the parsed decls into the translation unit
97/// held by Ctx.
98///
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.get(), 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) {
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.
128
129 ASTConsumer *Consumer = &S.getASTConsumer();
130
131 std::unique_ptr<Parser> ParseOP(
132 new Parser(S.getPreprocessor(), S, SkipFunctionBodies));
133 Parser &P = *ParseOP.get();
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
145 if (External)
146 External->StartTranslationUnit(Consumer);
147
148 // If a PCH through header is specified that does not have an include in
149 // the source, or a PCH is being created with #pragma hdrstop with nothing
150 // 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 P.Initialize();
157 Sema::ModuleImportState ImportState;
158 EnterExpressionEvaluationContext PotentiallyEvaluated(
159 S, Sema::ExpressionEvaluationContext::PotentiallyEvaluated);
160
161 for (bool AtEOF = P.ParseFirstTopLevelDecl(ADecl, ImportState); !AtEOF;
162 AtEOF = P.ParseTopLevelDecl(ADecl, ImportState)) {
163 // If we got a null return and something *was* parsed, ignore it. This
164 // is due to a top-level semicolon, an action override, or a parse error
165 // skipping something.
166 if (ADecl && !Consumer->HandleTopLevelDecl(ADecl.get()))
167 return;
168 }
169 }
170
171 // Process any TopLevelDecls generated by #pragma weak.
172 for (Decl *D : S.WeakTopLevelDecls())
173 Consumer->HandleTopLevelDecl(DeclGroupRef(D));
174
176
177 // Finalize the template instantiation observer chain.
178 // FIXME: This (and init.) should be done in the Sema class, but because
179 // Sema does not have a reliable "Finalize" function (it has a
180 // destructor, but it is not guaranteed to be called ("-disable-free")).
181 // So, do the initialization above and do the finalization here:
183
184 std::swap(OldCollectStats, S.CollectStats);
185 if (PrintStats) {
186 llvm::errs() << "\nSTATISTICS:\n";
187 if (HaveLexer) P.getActions().PrintStats();
191 Consumer->PrintStats();
192 }
193}
Defines the clang::ASTContext interface.
StringRef P
#define SM(sm)
Definition: Cuda.cpp:78
static void print(llvm::raw_ostream &OS, const T &V, ASTContext &, QualType)
Definition: InterpFrame.cpp:89
llvm::raw_ostream & OS
Definition: Logger.cpp:24
ASTConsumer - This is an abstract interface that should be implemented by clients that read ASTs.
Definition: ASTConsumer.h:33
virtual void HandleTranslationUnit(ASTContext &Ctx)
HandleTranslationUnit - This method is called when the ASTs for entire translation unit have been par...
Definition: ASTConsumer.h:66
virtual bool HandleTopLevelDecl(DeclGroupRef D)
HandleTopLevelDecl - Handle the specified top-level declaration.
Definition: ASTConsumer.cpp:18
virtual void PrintStats()
PrintStats - If desired, print any statistics.
Definition: ASTConsumer.h:137
Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
Definition: ASTContext.h:182
void PrintStats() const
ExternalASTSource * getExternalSource() const
Retrieve a pointer to the external AST source associated with this AST context, if any.
Definition: ASTContext.h:1167
Abstract interface for a consumer of code-completion information.
Decl - This represents one declaration (or definition), e.g.
Definition: DeclBase.h:83
static void EnableStatistics()
Definition: DeclBase.cpp:174
static void PrintStats()
Definition: DeclBase.cpp:178
RAII object that enters a new expression evaluation context.
Definition: Sema.h:13964
Abstract interface for external sources of AST nodes.
virtual void StartTranslationUnit(ASTConsumer *Consumer)
Function that will be invoked when we begin parsing a new translation unit involving this external AS...
Wrapper for void* pointer.
Definition: Ownership.h:50
PtrTy get() const
Definition: Ownership.h:80
Parser - This implements a parser for the C family of languages.
Definition: Parser.h:61
Engages in a tight little dance with the lexer to efficiently preprocess tokens.
Definition: Preprocessor.h:128
PreprocessorLexer * getCurrentLexer() const
Return the current lexer being lexed from.
void EnterMainSourceFile()
Enter the specified FileID as the main source file, which implicitly adds the builtin defines etc.
SourceManager & getSourceManager() const
Sema - This implements semantic analysis and AST building for C.
Definition: Sema.h:356
Preprocessor & getPreprocessor() const
Definition: Sema.h:1651
ASTContext & getASTContext() const
Definition: Sema.h:1652
SmallVectorImpl< Decl * > & WeakTopLevelDecls()
WeakTopLevelDeclDecls - access to #pragma weak-generated Decls.
Definition: Sema.h:2021
ASTConsumer & getASTConsumer() const
Definition: Sema.h:1653
bool CollectStats
Flag indicating whether or not to collect detailed statistics.
Definition: Sema.h:413
std::vector< std::unique_ptr< TemplateInstantiationCallback > > TemplateInstCallbacks
The template instantiation callbacks to trace or track instantiations (objects can be chained).
Definition: Sema.h:9445
ModuleImportState
An enumeration to represent the transition of states in parsing module fragments and imports.
Definition: Sema.h:3157
void print(raw_ostream &OS, const SourceManager &SM) const
This class handles loading and caching of source files into memory.
static void EnableStatistics()
Definition: Stmt.cpp:130
static void PrintStats()
Definition: Stmt.cpp:100
Token - This structure provides full information about a lexed token.
Definition: Token.h:35
SourceLocation getLocation() const
Return a source location identifier for the specified offset in the current file.
Definition: Token.h:126
unsigned getLength() const
Definition: Token.h:129
bool is(tok::TokenKind K) const
is/isNot - Predicates to check if this token is a specific kind, as in "if (Tok.is(tok::l_brace)) {....
Definition: Token.h:98
bool isAnnotation() const
Return true if this is any of tok::annot_* kind tokens.
Definition: Token.h:120
void ParseAST(Preprocessor &pp, ASTConsumer *C, ASTContext &Ctx, bool PrintStats=false, TranslationUnitKind TUKind=TU_Complete, CodeCompleteConsumer *CompletionConsumer=nullptr, bool SkipFunctionBodies=false)
Parse the entire file specified, notifying the ASTConsumer as the file is parsed.
Definition: ParseAST.cpp:99
void initialize(TemplateInstantiationCallbackPtrs &Callbacks, const Sema &TheSema)
TranslationUnitKind
Describes the kind of translation unit being processed.
Definition: LangOptions.h:917
void finalize(TemplateInstantiationCallbackPtrs &Callbacks, const Sema &TheSema)
YAML serialization mapping.
Definition: Dominators.h:30