clang  6.0.0svn
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"
24 #include "llvm/Support/CrashRecoveryContext.h"
25 #include <cstdio>
26 #include <memory>
27 
28 using namespace clang;
29 
30 namespace {
31 
32 /// Resets LLVM's pretty stack state so that stack traces are printed correctly
33 /// when there are nested CrashRecoveryContexts and the inner one recovers from
34 /// a crash.
35 class ResetStackCleanup
36  : public llvm::CrashRecoveryContextCleanupBase<ResetStackCleanup,
37  const void> {
38 public:
39  ResetStackCleanup(llvm::CrashRecoveryContext *Context, const void *Top)
40  : llvm::CrashRecoveryContextCleanupBase<ResetStackCleanup, const void>(
41  Context, Top) {}
42  void recoverResources() override {
43  llvm::RestorePrettyStackState(resource);
44  }
45 };
46 
47 /// If a crash happens while the parser is active, an entry is printed for it.
48 class PrettyStackTraceParserEntry : public llvm::PrettyStackTraceEntry {
49  const Parser &P;
50 public:
51  PrettyStackTraceParserEntry(const Parser &p) : P(p) {}
52  void print(raw_ostream &OS) const override;
53 };
54 
55 /// If a crash happens while the parser is active, print out a line indicating
56 /// what the current token is.
57 void PrettyStackTraceParserEntry::print(raw_ostream &OS) const {
58  const Token &Tok = P.getCurToken();
59  if (Tok.is(tok::eof)) {
60  OS << "<eof> parser at end of file\n";
61  return;
62  }
63 
64  if (Tok.getLocation().isInvalid()) {
65  OS << "<unknown> parser at unknown location\n";
66  return;
67  }
68 
69  const Preprocessor &PP = P.getPreprocessor();
70  Tok.getLocation().print(OS, PP.getSourceManager());
71  if (Tok.isAnnotation()) {
72  OS << ": at annotation token\n";
73  } else {
74  // Do the equivalent of PP.getSpelling(Tok) except for the parts that would
75  // allocate memory.
76  bool Invalid = false;
77  const SourceManager &SM = P.getPreprocessor().getSourceManager();
78  unsigned Length = Tok.getLength();
79  const char *Spelling = SM.getCharacterData(Tok.getLocation(), &Invalid);
80  if (Invalid) {
81  OS << ": unknown current parser token\n";
82  return;
83  }
84  OS << ": current parser token '" << StringRef(Spelling, Length) << "'\n";
85  }
86 }
87 
88 } // namespace
89 
90 //===----------------------------------------------------------------------===//
91 // Public interface to the file
92 //===----------------------------------------------------------------------===//
93 
94 /// ParseAST - Parse the entire file specified, notifying the ASTConsumer as
95 /// the file is parsed. This inserts the parsed decls into the translation unit
96 /// held by Ctx.
97 ///
99  ASTContext &Ctx, bool PrintStats,
100  TranslationUnitKind TUKind,
101  CodeCompleteConsumer *CompletionConsumer,
102  bool SkipFunctionBodies) {
103 
104  std::unique_ptr<Sema> S(
105  new Sema(PP, Ctx, *Consumer, TUKind, CompletionConsumer));
106 
107  // Recover resources if we crash before exiting this method.
108  llvm::CrashRecoveryContextCleanupRegistrar<Sema> CleanupSema(S.get());
109 
110  ParseAST(*S.get(), PrintStats, SkipFunctionBodies);
111 }
112 
113 void clang::ParseAST(Sema &S, bool PrintStats, bool SkipFunctionBodies) {
114  // Collect global stats on Decls/Stmts (until we have a module streamer).
115  if (PrintStats) {
118  }
119 
120  // Also turn on collection of stats inside of the Sema object.
121  bool OldCollectStats = PrintStats;
122  std::swap(OldCollectStats, S.CollectStats);
123 
124  ASTConsumer *Consumer = &S.getASTConsumer();
125 
126  std::unique_ptr<Parser> ParseOP(
127  new Parser(S.getPreprocessor(), S, SkipFunctionBodies));
128  Parser &P = *ParseOP.get();
129 
130  llvm::CrashRecoveryContextCleanupRegistrar<const void, ResetStackCleanup>
131  CleanupPrettyStack(llvm::SavePrettyStackState());
132  PrettyStackTraceParserEntry CrashInfo(P);
133 
134  // Recover resources if we crash before exiting this method.
135  llvm::CrashRecoveryContextCleanupRegistrar<Parser>
136  CleanupParser(ParseOP.get());
137 
139  P.Initialize();
140 
143  if (External)
144  External->StartTranslationUnit(Consumer);
145 
146  for (bool AtEOF = P.ParseFirstTopLevelDecl(ADecl); !AtEOF;
147  AtEOF = P.ParseTopLevelDecl(ADecl)) {
148  // If we got a null return and something *was* parsed, ignore it. This
149  // is due to a top-level semicolon, an action override, or a parse error
150  // skipping something.
151  if (ADecl && !Consumer->HandleTopLevelDecl(ADecl.get()))
152  return;
153  }
154 
155  // Process any TopLevelDecls generated by #pragma weak.
156  for (Decl *D : S.WeakTopLevelDecls())
157  Consumer->HandleTopLevelDecl(DeclGroupRef(D));
158 
159  Consumer->HandleTranslationUnit(S.getASTContext());
160 
161  std::swap(OldCollectStats, S.CollectStats);
162  if (PrintStats) {
163  llvm::errs() << "\nSTATISTICS:\n";
164  P.getActions().PrintStats();
168  Consumer->PrintStats();
169  }
170 }
Defines the clang::ASTContext interface.
PtrTy get() const
Definition: Ownership.h:74
SmallVectorImpl< Decl * > & WeakTopLevelDecls()
WeakTopLevelDeclDecls - access to #pragma weak-generated Decls.
Definition: Sema.h:1366
void Initialize()
Initialize - Warm up the parser.
Definition: Parser.cpp:437
ASTConsumer - This is an abstract interface that should be implemented by clients that read ASTs...
Definition: ASTConsumer.h:34
DominatorTree GraphTraits specialization so the DominatorTree can be iterable by generic graph iterat...
Definition: Dominators.h:26
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:81
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:45
Parser - This implements a parser for the C family of languages.
Definition: Parser.h:57
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:128
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:416
Sema - This implements semantic analysis and AST building for C.
Definition: Sema.h:274
Sema & getActions() const
Definition: Parser.h:274
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:1199
const SourceManager & SM
Definition: Format.cpp:1308
SourceManager & getSourceManager() const
Definition: Preprocessor.h:732
Abstract interface for external sources of AST nodes.
void PrintStats() const
Definition: ASTContext.cpp:830
ASTContext & getASTContext() const
Definition: Sema.h:1200
static void PrintStats()
Definition: Stmt.cpp:62
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:98
bool CollectStats
Flag indicating whether or not to collect detailed statistics.
Definition: Sema.h:322
bool ParseTopLevelDecl(DeclGroupPtrTy &Result)
ParseTopLevelDecl - Parse one top-level declaration.
Definition: Parser.cpp:545
ASTConsumer & getASTConsumer() const
Definition: Sema.h:1201
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:1017
unsigned getLength() const
Definition: Token.h:127
TranslationUnitKind
Describes the kind of translation unit being processed.
Definition: LangOptions.h:241
static void PrintStats()
Definition: DeclBase.cpp:149
virtual bool HandleTopLevelDecl(DeclGroupRef D)
HandleTopLevelDecl - Handle the specified top-level declaration.
Definition: ASTConsumer.cpp:19
static void EnableStatistics()
Definition: DeclBase.cpp:145
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:528
Engages in a tight little dance with the lexer to efficiently preprocess tokens.
Definition: Preprocessor.h:98
static void EnableStatistics()
Definition: Stmt.cpp:92