clang  8.0.0svn
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"
22 #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) {
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  P.Initialize();
156  for (bool AtEOF = P.ParseFirstTopLevelDecl(ADecl); !AtEOF;
157  AtEOF = P.ParseTopLevelDecl(ADecl)) {
158  // If we got a null return and something *was* parsed, ignore it. This
159  // is due to a top-level semicolon, an action override, or a parse error
160  // skipping something.
161  if (ADecl && !Consumer->HandleTopLevelDecl(ADecl.get()))
162  return;
163  }
164  }
165 
166  // Process any TopLevelDecls generated by #pragma weak.
167  for (Decl *D : S.WeakTopLevelDecls())
168  Consumer->HandleTopLevelDecl(DeclGroupRef(D));
169 
170  Consumer->HandleTranslationUnit(S.getASTContext());
171 
172  // Finalize the template instantiation observer chain.
173  // FIXME: This (and init.) should be done in the Sema class, but because
174  // Sema does not have a reliable "Finalize" function (it has a
175  // destructor, but it is not guaranteed to be called ("-disable-free")).
176  // So, do the initialization above and do the finalization here:
178 
179  std::swap(OldCollectStats, S.CollectStats);
180  if (PrintStats) {
181  llvm::errs() << "\nSTATISTICS:\n";
182  if (HaveLexer) P.getActions().PrintStats();
186  Consumer->PrintStats();
187  }
188 }
Defines the clang::ASTContext interface.
PtrTy get() const
Definition: Ownership.h:81
SmallVectorImpl< Decl * > & WeakTopLevelDecls()
WeakTopLevelDeclDecls - access to #pragma weak-generated Decls.
Definition: Sema.h:1373
void Initialize()
Initialize - Warm up the parser.
Definition: Parser.cpp:438
ASTConsumer - This is an abstract interface that should be implemented by clients that read ASTs...
Definition: ASTConsumer.h:34
std::vector< std::unique_ptr< TemplateInstantiationCallback > > TemplateInstCallbacks
The template instantiation callbacks to trace or track instantiations (objects can be chained)...
Definition: Sema.h:7298
DominatorTree GraphTraits specialization so the DominatorTree can be iterable by generic graph iterat...
Definition: Dominators.h:30
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
Decl - This represents one declaration (or definition), e.g.
Definition: DeclBase.h:87
StringRef P
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:51
Parser - This implements a parser for the C family of languages.
Definition: Parser.h:57
void finalize(TemplateInstantiationCallbackPtrs &Callbacks, const Sema &TheSema)
virtual void PrintStats()
PrintStats - If desired, print any statistics.
Definition: ASTConsumer.h:133
bool isAnnotation() const
Return true if this is any of tok::annot_* kind tokens.
Definition: Token.h:118
void print(raw_ostream &OS, const SourceManager &SM) const
Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
Definition: ASTContext.h:154
Token - This structure provides full information about a lexed token.
Definition: Token.h:35
const FormatToken & Tok
void PrintStats() const
Print out statistics about the semantic analysis.
Definition: Sema.cpp:420
Sema - This implements semantic analysis and AST building for C.
Definition: Sema.h:277
Sema & getActions() const
Definition: Parser.h:369
void EnterMainSourceFile()
Enter the specified FileID as the main source file, which implicitly adds the builtin defines etc...
SourceLocation getLocation() const
Return a source location identifier for the specified offset in the current file. ...
Definition: Token.h:124
virtual void HandleTranslationUnit(ASTContext &Ctx)
HandleTranslationUnit - This method is called when the ASTs for entire translation unit have been par...
Definition: ASTConsumer.h:67
Preprocessor & getPreprocessor() const
Definition: Sema.h:1218
const SourceManager & SM
Definition: Format.cpp:1472
SourceManager & getSourceManager() const
Definition: Preprocessor.h:831
Abstract interface for external sources of AST nodes.
void PrintStats() const
Definition: ASTContext.cpp:868
ASTContext & getASTContext() const
Definition: Sema.h:1219
static void PrintStats()
Definition: Stmt.cpp:79
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
bool CollectStats
Flag indicating whether or not to collect detailed statistics.
Definition: Sema.h:325
PreprocessorLexer * getCurrentLexer() const
Return the current lexer being lexed from.
Definition: Preprocessor.h:903
bool ParseTopLevelDecl(DeclGroupPtrTy &Result)
ParseTopLevelDecl - Parse one top-level declaration.
Definition: Parser.cpp:546
ASTConsumer & getASTConsumer() const
Definition: Sema.h:1220
Abstract interface for a consumer of code-completion information.
Dataflow Directional Tag Classes.
virtual void StartTranslationUnit(ASTConsumer *Consumer)
Function that will be invoked when we begin parsing a new translation unit involving this external AS...
ExternalASTSource * getExternalSource() const
Retrieve a pointer to the external AST source associated with this AST context, if any...
Definition: ASTContext.h:1089
unsigned getLength() const
Definition: Token.h:127
TranslationUnitKind
Describes the kind of translation unit being processed.
Definition: LangOptions.h:329
void initialize(TemplateInstantiationCallbackPtrs &Callbacks, const Sema &TheSema)
static void PrintStats()
Definition: DeclBase.cpp:169
virtual bool HandleTopLevelDecl(DeclGroupRef D)
HandleTopLevelDecl - Handle the specified top-level declaration.
Definition: ASTConsumer.cpp:19
static void EnableStatistics()
Definition: DeclBase.cpp:165
This class handles loading and caching of source files into memory.
bool ParseFirstTopLevelDecl(DeclGroupPtrTy &Result)
Parse the first top-level declaration in a translation unit.
Definition: Parser.cpp:529
Engages in a tight little dance with the lexer to efficiently preprocess tokens.
Definition: Preprocessor.h:127
static void EnableStatistics()
Definition: Stmt.cpp:109