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/ExternalASTSource.h"
18#include "clang/AST/Stmt.h"
19#include "clang/Parse/ParseDiagnostic.h"
20#include "clang/Parse/Parser.h"
21#include "clang/Sema/CodeCompleteConsumer.h"
22#include "clang/Sema/ExternalSemaSource.h"
23#include "clang/Sema/Sema.h"
24#include "clang/Sema/SemaConsumer.h"
25#include "llvm/Support/CrashRecoveryContext.h"
26#include <cstdio>
27#include <memory>
28
29using namespace clang;
30
31namespace {
32
33/// If a crash happens while the parser is active, an entry is printed for it.
34class PrettyStackTraceParserEntry : public llvm::PrettyStackTraceEntry {
35  const Parser &P;
36public:
37  PrettyStackTraceParserEntry(const Parser &p) : P(p) {}
38  void print(raw_ostream &OS) const override;
39};
40
41/// If a crash happens while the parser is active, print out a line indicating
42/// what the current token is.
43void PrettyStackTraceParserEntry::print(raw_ostream &OS) const {
44  const Token &Tok = P.getCurToken();
45  if (Tok.is(tok::eof)) {
46    OS << "<eof> parser at end of file\n";
47    return;
48  }
49
50  if (Tok.getLocation().isInvalid()) {
51    OS << "<unknown> parser at unknown location\n";
52    return;
53  }
54
55  const Preprocessor &PP = P.getPreprocessor();
56  Tok.getLocation().print(OS, PP.getSourceManager());
57  if (Tok.isAnnotation()) {
58    OS << ": at annotation token\n";
59  } else {
60    // Do the equivalent of PP.getSpelling(Tok) except for the parts that would
61    // allocate memory.
62    bool Invalid = false;
63    const SourceManager &SM = P.getPreprocessor().getSourceManager();
64    unsigned Length = Tok.getLength();
65    const char *Spelling = SM.getCharacterData(Tok.getLocation(), &Invalid);
66    if (Invalid) {
67      OS << ": unknown current parser token\n";
68      return;
69    }
70    OS << ": current parser token '" << StringRef(Spelling, Length) << "'\n";
71  }
72}
73
74}  // namespace
75
76//===----------------------------------------------------------------------===//
77// Public interface to the file
78//===----------------------------------------------------------------------===//
79
80/// ParseAST - Parse the entire file specified, notifying the ASTConsumer as
81/// the file is parsed.  This inserts the parsed decls into the translation unit
82/// held by Ctx.
83///
84void clang::ParseAST(Preprocessor &PP, ASTConsumer *Consumer,
85                     ASTContext &Ctx, bool PrintStats,
86                     TranslationUnitKind TUKind,
87                     CodeCompleteConsumer *CompletionConsumer,
88                     bool SkipFunctionBodies) {
89
90  std::unique_ptr<Sema> S(
91      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  std::unique_ptr<Parser> ParseOP(
113      new Parser(S.getPreprocessor(), S, 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 (Decl *D : S.WeakTopLevelDecls())
149    Consumer->HandleTopLevelDecl(DeclGroupRef(D));
150
151  Consumer->HandleTranslationUnit(S.getASTContext());
152
153  std::swap(OldCollectStats, S.CollectStats);
154  if (PrintStats) {
155    llvm::errs() << "\nSTATISTICS:\n";
156    P.getActions().PrintStats();
157    S.getASTContext().PrintStats();
158    Decl::PrintStats();
159    Stmt::PrintStats();
160    Consumer->PrintStats();
161  }
162}
163