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/Sema.h"
23 #include "clang/Sema/SemaConsumer.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:
ResetStackCleanup(llvm::CrashRecoveryContext * Context,const void * Top)39 ResetStackCleanup(llvm::CrashRecoveryContext *Context, const void *Top)
40 : llvm::CrashRecoveryContextCleanupBase<ResetStackCleanup, const void>(
41 Context, Top) {}
recoverResources()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:
PrettyStackTraceParserEntry(const Parser & p)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.
print(raw_ostream & OS) const57 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 ///
ParseAST(Preprocessor & PP,ASTConsumer * Consumer,ASTContext & Ctx,bool PrintStats,TranslationUnitKind TUKind,CodeCompleteConsumer * CompletionConsumer,bool SkipFunctionBodies)98 void clang::ParseAST(Preprocessor &PP, ASTConsumer *Consumer,
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
ParseAST(Sema & S,bool PrintStats,bool SkipFunctionBodies)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) {
116 Decl::EnableStatistics();
117 Stmt::EnableStatistics();
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
138 S.getPreprocessor().EnterMainSourceFile();
139 P.Initialize();
140
141 // C11 6.9p1 says translation units must have at least one top-level
142 // declaration. C++ doesn't have this restriction. We also don't want to
143 // complain if we have a precompiled header, although technically if the PCH
144 // is empty we should still emit the (pedantic) diagnostic.
145 Parser::DeclGroupPtrTy ADecl;
146 ExternalASTSource *External = S.getASTContext().getExternalSource();
147 if (External)
148 External->StartTranslationUnit(Consumer);
149
150 if (P.ParseTopLevelDecl(ADecl)) {
151 if (!External && !S.getLangOpts().CPlusPlus)
152 P.Diag(diag::ext_empty_translation_unit);
153 } else {
154 do {
155 // If we got a null return and something *was* parsed, ignore it. This
156 // is due to a top-level semicolon, an action override, or a parse error
157 // skipping something.
158 if (ADecl && !Consumer->HandleTopLevelDecl(ADecl.get()))
159 return;
160 } while (!P.ParseTopLevelDecl(ADecl));
161 }
162
163 // Process any TopLevelDecls generated by #pragma weak.
164 for (Decl *D : S.WeakTopLevelDecls())
165 Consumer->HandleTopLevelDecl(DeclGroupRef(D));
166
167 Consumer->HandleTranslationUnit(S.getASTContext());
168
169 std::swap(OldCollectStats, S.CollectStats);
170 if (PrintStats) {
171 llvm::errs() << "\nSTATISTICS:\n";
172 P.getActions().PrintStats();
173 S.getASTContext().PrintStats();
174 Decl::PrintStats();
175 Stmt::PrintStats();
176 Consumer->PrintStats();
177 }
178 }
179