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
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:
ResetStackCleanup(llvm::CrashRecoveryContext * Context,const void * Top)40 ResetStackCleanup(llvm::CrashRecoveryContext *Context, const void *Top)
41 : llvm::CrashRecoveryContextCleanupBase<ResetStackCleanup, const void>(
42 Context, Top) {}
recoverResources()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:
PrettyStackTraceParserEntry(const Parser & p)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.
print(raw_ostream & OS) const58 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 ///
ParseAST(Preprocessor & PP,ASTConsumer * Consumer,ASTContext & Ctx,bool PrintStats,TranslationUnitKind TUKind,CodeCompleteConsumer * CompletionConsumer,bool SkipFunctionBodies)99 void clang::ParseAST(Preprocessor &PP, ASTConsumer *Consumer,
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
ParseAST(Sema & S,bool PrintStats,bool SkipFunctionBodies)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) {
117 Decl::EnableStatistics();
118 Stmt::EnableStatistics();
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 ASTConsumer *Consumer = &S.getASTConsumer();
126
127 std::unique_ptr<Parser> ParseOP(
128 new Parser(S.getPreprocessor(), S, SkipFunctionBodies));
129 Parser &P = *ParseOP.get();
130
131 llvm::CrashRecoveryContextCleanupRegistrar<const void, ResetStackCleanup>
132 CleanupPrettyStack(llvm::SavePrettyStackState());
133 PrettyStackTraceParserEntry CrashInfo(P);
134
135 // Recover resources if we crash before exiting this method.
136 llvm::CrashRecoveryContextCleanupRegistrar<Parser>
137 CleanupParser(ParseOP.get());
138
139 S.getPreprocessor().EnterMainSourceFile();
140 P.Initialize();
141
142 // C11 6.9p1 says translation units must have at least one top-level
143 // declaration. C++ doesn't have this restriction. We also don't want to
144 // complain if we have a precompiled header, although technically if the PCH
145 // is empty we should still emit the (pedantic) diagnostic.
146 Parser::DeclGroupPtrTy ADecl;
147 ExternalASTSource *External = S.getASTContext().getExternalSource();
148 if (External)
149 External->StartTranslationUnit(Consumer);
150
151 if (P.ParseTopLevelDecl(ADecl)) {
152 if (!External && !S.getLangOpts().CPlusPlus)
153 P.Diag(diag::ext_empty_translation_unit);
154 } else {
155 do {
156 // If we got a null return and something *was* parsed, ignore it. This
157 // is due to a top-level semicolon, an action override, or a parse error
158 // skipping something.
159 if (ADecl && !Consumer->HandleTopLevelDecl(ADecl.get()))
160 return;
161 } while (!P.ParseTopLevelDecl(ADecl));
162 }
163
164 // Process any TopLevelDecls generated by #pragma weak.
165 for (Decl *D : S.WeakTopLevelDecls())
166 Consumer->HandleTopLevelDecl(DeclGroupRef(D));
167
168 Consumer->HandleTranslationUnit(S.getASTContext());
169
170 std::swap(OldCollectStats, S.CollectStats);
171 if (PrintStats) {
172 llvm::errs() << "\nSTATISTICS:\n";
173 P.getActions().PrintStats();
174 S.getASTContext().PrintStats();
175 Decl::PrintStats();
176 Stmt::PrintStats();
177 Consumer->PrintStats();
178 }
179 }
180