clang  3.8.0
ParseAST.cpp
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1 //===--- ParseAST.cpp - Provide the clang::ParseAST method ----------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file implements the clang::ParseAST method.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "clang/Parse/ParseAST.h"
15 #include "clang/AST/ASTConsumer.h"
16 #include "clang/AST/ASTContext.h"
18 #include "clang/AST/Stmt.h"
20 #include "clang/Parse/Parser.h"
23 #include "clang/Sema/Sema.h"
25 #include "llvm/Support/CrashRecoveryContext.h"
26 #include <cstdio>
27 #include <memory>
28 
29 using namespace clang;
30 
31 namespace {
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.
36 class ResetStackCleanup
37  : public llvm::CrashRecoveryContextCleanupBase<ResetStackCleanup,
38  const void> {
39 public:
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.
49 class PrettyStackTraceParserEntry : public llvm::PrettyStackTraceEntry {
50  const Parser &P;
51 public:
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.
58 void 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 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 
114 void clang::ParseAST(Sema &S, bool PrintStats, bool SkipFunctionBodies) {
115  // Collect global stats on Decls/Stmts (until we have a module streamer).
116  if (PrintStats) {
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  ASTConsumer *Consumer = &S.getASTConsumer();
126 
127  std::unique_ptr<Parser> ParseOP(
128  new Parser(S.getPreprocessor(), S, SkipFunctionBodies));
129  Parser &P = *ParseOP.get();
130 
131  llvm::CrashRecoveryContextCleanupRegistrar<const void, ResetStackCleanup>
132  CleanupPrettyStack(llvm::SavePrettyStackState());
133  PrettyStackTraceParserEntry CrashInfo(P);
134 
135  // Recover resources if we crash before exiting this method.
136  llvm::CrashRecoveryContextCleanupRegistrar<Parser>
137  CleanupParser(ParseOP.get());
138 
140  P.Initialize();
141 
142  // C11 6.9p1 says translation units must have at least one top-level
143  // declaration. C++ doesn't have this restriction. We also don't want to
144  // complain if we have a precompiled header, although technically if the PCH
145  // is empty we should still emit the (pedantic) diagnostic.
148  if (External)
149  External->StartTranslationUnit(Consumer);
150 
151  if (P.ParseTopLevelDecl(ADecl)) {
152  if (!External && !S.getLangOpts().CPlusPlus)
153  P.Diag(diag::ext_empty_translation_unit);
154  } else {
155  do {
156  // If we got a null return and something *was* parsed, ignore it. This
157  // is due to a top-level semicolon, an action override, or a parse error
158  // skipping something.
159  if (ADecl && !Consumer->HandleTopLevelDecl(ADecl.get()))
160  return;
161  } while (!P.ParseTopLevelDecl(ADecl));
162  }
163 
164  // Process any TopLevelDecls generated by #pragma weak.
165  for (Decl *D : S.WeakTopLevelDecls())
166  Consumer->HandleTopLevelDecl(DeclGroupRef(D));
167 
168  Consumer->HandleTranslationUnit(S.getASTContext());
169 
170  std::swap(OldCollectStats, S.CollectStats);
171  if (PrintStats) {
172  llvm::errs() << "\nSTATISTICS:\n";
173  P.getActions().PrintStats();
176  Stmt::PrintStats();
177  Consumer->PrintStats();
178  }
179 }
SourceManager & getSourceManager() const
Definition: Preprocessor.h:687
Defines the clang::ASTContext interface.
unsigned Length
SmallVectorImpl< Decl * > & WeakTopLevelDecls()
WeakTopLevelDeclDecls - access to #pragma weak-generated Decls.
Definition: Sema.h:1209
void Initialize()
Initialize - Warm up the parser.
ASTConsumer - This is an abstract interface that should be implemented by clients that read ASTs...
Definition: ASTConsumer.h:36
const LangOptions & getLangOpts() const
Definition: Sema.h:1041
Decl - This represents one declaration (or definition), e.g.
Definition: DeclBase.h:77
const char * getCharacterData(SourceLocation SL, bool *Invalid=nullptr) const
Return a pointer to the start of the specified location in the appropriate spelling MemoryBuffer...
Wrapper for void* pointer.
Definition: Ownership.h:45
Parser - This implements a parser for the C family of languages.
Definition: Parse/Parser.h:56
virtual void PrintStats()
PrintStats - If desired, print any statistics.
Definition: ASTConsumer.h:146
void PrintStats() const
Definition: ASTContext.cpp:822
Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
Definition: ASTContext.h:91
Token - This structure provides full information about a lexed token.
Definition: Token.h:37
bool isInvalid() const
AnnotatingParser & P
Sema - This implements semantic analysis and AST building for C.
Definition: Sema.h:259
ASTContext * Context
SourceManager & SM
void EnterMainSourceFile()
Enter the specified FileID as the main source file, which implicitly adds the builtin defines etc...
virtual void HandleTranslationUnit(ASTContext &Ctx)
HandleTranslationUnit - This method is called when the ASTs for entire translation unit have been par...
Definition: ASTConsumer.h:69
SourceLocation getLocation() const
Return a source location identifier for the specified offset in the current file. ...
Definition: Token.h:124
Abstract interface for external sources of AST nodes.
void print(raw_ostream &OS, const SourceManager &SM) const
ExternalASTSource * getExternalSource() const
Retrieve a pointer to the external AST source associated with this AST context, if any...
Definition: ASTContext.h:932
ASTContext & getASTContext() const
Definition: Sema.h:1048
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
ASTConsumer & getASTConsumer() const
Definition: Sema.h:1049
bool CollectStats
Flag indicating whether or not to collect detailed statistics.
Definition: Sema.h:301
PtrTy get() const
Definition: Ownership.h:74
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:95
bool ParseTopLevelDecl(DeclGroupPtrTy &Result)
ParseTopLevelDecl - Parse one top-level declaration.
Abstract interface for a consumer of code-completion information.
Sema & getActions() const
Definition: Parse/Parser.h:247
static __inline__ uint32_t volatile uint32_t * p
Definition: arm_acle.h:75
virtual void StartTranslationUnit(ASTConsumer *Consumer)
Function that will be invoked when we begin parsing a new translation unit involving this external AS...
DiagnosticBuilder Diag(SourceLocation Loc, unsigned DiagID)
TranslationUnitKind
Describes the kind of translation unit being processed.
Definition: LangOptions.h:178
void PrintStats() const
Print out statistics about the semantic analysis.
Definition: Sema.cpp:344
static void PrintStats()
Definition: DeclBase.cpp:136
unsigned getLength() const
Definition: Token.h:127
virtual bool HandleTopLevelDecl(DeclGroupRef D)
HandleTopLevelDecl - Handle the specified top-level declaration.
Definition: ASTConsumer.cpp:20
static void EnableStatistics()
Definition: DeclBase.cpp:132
bool isAnnotation() const
Return true if this is any of tok::annot_* kind tokens.
Definition: Token.h:118
This class handles loading and caching of source files into memory.
Preprocessor & getPreprocessor() const
Definition: Sema.h:1047
Engages in a tight little dance with the lexer to efficiently preprocess tokens.
Definition: Preprocessor.h:96