ParseAST.cpp revision 263509 
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"
17#include "clang/AST/DeclCXX.h"
18#include "clang/AST/ExternalASTSource.h"
19#include "clang/AST/Stmt.h"
20#include "clang/Parse/ParseDiagnostic.h"
21#include "clang/Parse/Parser.h"
22#include "clang/Sema/CodeCompleteConsumer.h"
23#include "clang/Sema/ExternalSemaSource.h"
24#include "clang/Sema/Sema.h"
25#include "clang/Sema/SemaConsumer.h"
26#include "llvm/ADT/OwningPtr.h"
27#include "llvm/Support/CrashRecoveryContext.h"
28#include <cstdio>
29
30using namespace clang;
31
32namespace {
33
34/// If a crash happens while the parser is active, an entry is printed for it.
35class PrettyStackTraceParserEntry : public llvm::PrettyStackTraceEntry {
36  const Parser &P;
37public:
38  PrettyStackTraceParserEntry(const Parser &p) : P(p) {}
39  virtual void print(raw_ostream &OS) const;
40};
41
42/// If a crash happens while the parser is active, print out a line indicating
43/// what the current token is.
44void PrettyStackTraceParserEntry::print(raw_ostream &OS) const {
45  const Token &Tok = P.getCurToken();
46  if (Tok.is(tok::eof)) {
47    OS << "<eof> parser at end of file\n";
48    return;
49  }
50
51  if (Tok.getLocation().isInvalid()) {
52    OS << "<unknown> parser at unknown location\n";
53    return;
54  }
55
56  const Preprocessor &PP = P.getPreprocessor();
57  Tok.getLocation().print(OS, PP.getSourceManager());
58  if (Tok.isAnnotation()) {
59    OS << ": at annotation token\n";
60  } else {
61    // Do the equivalent of PP.getSpelling(Tok) except for the parts that would
62    // allocate memory.
63    bool Invalid = false;
64    const SourceManager &SM = P.getPreprocessor().getSourceManager();
65    unsigned Length = Tok.getLength();
66    const char *Spelling = SM.getCharacterData(Tok.getLocation(), &Invalid);
67    if (Invalid) {
68      OS << ": unknown current parser token\n";
69      return;
70    }
71    OS << ": current parser token '" << StringRef(Spelling, Length) << "'\n";
72  }
73}
74
75}  // namespace
76
77//===----------------------------------------------------------------------===//
78// Public interface to the file
79//===----------------------------------------------------------------------===//
80
81/// ParseAST - Parse the entire file specified, notifying the ASTConsumer as
82/// the file is parsed.  This inserts the parsed decls into the translation unit
83/// held by Ctx.
84///
85void clang::ParseAST(Preprocessor &PP, ASTConsumer *Consumer,
86                     ASTContext &Ctx, bool PrintStats,
87                     TranslationUnitKind TUKind,
88                     CodeCompleteConsumer *CompletionConsumer,
89                     bool SkipFunctionBodies) {
90
91  OwningPtr<Sema> S(new Sema(PP, Ctx, *Consumer, TUKind, CompletionConsumer));
92
93  // Recover resources if we crash before exiting this method.
94  llvm::CrashRecoveryContextCleanupRegistrar<Sema> CleanupSema(S.get());
95
96  ParseAST(*S.get(), PrintStats, SkipFunctionBodies);
97}
98
99void clang::ParseAST(Sema &S, bool PrintStats, bool SkipFunctionBodies) {
100  // Collect global stats on Decls/Stmts (until we have a module streamer).
101  if (PrintStats) {
102    Decl::EnableStatistics();
103    Stmt::EnableStatistics();
104  }
105
106  // Also turn on collection of stats inside of the Sema object.
107  bool OldCollectStats = PrintStats;
108  std::swap(OldCollectStats, S.CollectStats);
109
110  ASTConsumer *Consumer = &S.getASTConsumer();
111
112  OwningPtr<Parser> ParseOP(new Parser(S.getPreprocessor(), S,
113                                       SkipFunctionBodies));
114  Parser &P = *ParseOP.get();
115
116  PrettyStackTraceParserEntry CrashInfo(P);
117
118  // Recover resources if we crash before exiting this method.
119  llvm::CrashRecoveryContextCleanupRegistrar<Parser>
120    CleanupParser(ParseOP.get());
121
122  S.getPreprocessor().EnterMainSourceFile();
123  P.Initialize();
124
125  // C11 6.9p1 says translation units must have at least one top-level
126  // declaration. C++ doesn't have this restriction. We also don't want to
127  // complain if we have a precompiled header, although technically if the PCH
128  // is empty we should still emit the (pedantic) diagnostic.
129  Parser::DeclGroupPtrTy ADecl;
130  ExternalASTSource *External = S.getASTContext().getExternalSource();
131  if (External)
132    External->StartTranslationUnit(Consumer);
133
134  if (P.ParseTopLevelDecl(ADecl)) {
135    if (!External && !S.getLangOpts().CPlusPlus)
136      P.Diag(diag::ext_empty_translation_unit);
137  } else {
138    do {
139      // If we got a null return and something *was* parsed, ignore it.  This
140      // is due to a top-level semicolon, an action override, or a parse error
141      // skipping something.
142      if (ADecl && !Consumer->HandleTopLevelDecl(ADecl.get()))
143        return;
144    } while (!P.ParseTopLevelDecl(ADecl));
145  }
146
147  // Process any TopLevelDecls generated by #pragma weak.
148  for (SmallVectorImpl<Decl *>::iterator
149       I = S.WeakTopLevelDecls().begin(),
150       E = S.WeakTopLevelDecls().end(); I != E; ++I)
151    Consumer->HandleTopLevelDecl(DeclGroupRef(*I));
152
153  Consumer->HandleTranslationUnit(S.getASTContext());
154
155  std::swap(OldCollectStats, S.CollectStats);
156  if (PrintStats) {
157    llvm::errs() << "\nSTATISTICS:\n";
158    P.getActions().PrintStats();
159    S.getASTContext().PrintStats();
160    Decl::PrintStats();
161    Stmt::PrintStats();
162    Consumer->PrintStats();
163  }
164}
165