Sema.cpp revision 0701bbb228dfd87e1fe82a0a4b7b9facfecb43da 
1//===--- Sema.cpp - AST Builder and Semantic Analysis Implementation ------===//
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 actions class which performs semantic analysis and
11// builds an AST out of a parse stream.
12//
13//===----------------------------------------------------------------------===//
14
15#include "Sema.h"
16#include "clang/AST/ASTContext.h"
17#include "clang/AST/DeclObjC.h"
18#include "clang/AST/Expr.h"
19#include "clang/Lex/Preprocessor.h"
20#include "clang/Basic/Diagnostic.h"
21using namespace clang;
22
23/// ConvertQualTypeToStringFn - This function is used to pretty print the
24/// specified QualType as a string in diagnostics.
25static void ConvertArgToStringFn(Diagnostic::ArgumentKind Kind, intptr_t Val,
26                                      const char *Modifier, unsigned ModLen,
27                                      const char *Argument, unsigned ArgLen,
28                                      llvm::SmallVectorImpl<char> &Output) {
29
30  std::string S;
31  if (Kind == Diagnostic::ak_qualtype) {
32    QualType Ty(QualType::getFromOpaquePtr(reinterpret_cast<void*>(Val)));
33
34    // FIXME: Playing with std::string is really slow.
35    S = Ty.getAsString();
36
37    assert(ModLen == 0 && ArgLen == 0 &&
38           "Invalid modifier for QualType argument");
39
40  } else {
41    assert(Kind == Diagnostic::ak_declarationname);
42
43    DeclarationName N = DeclarationName::getFromOpaqueInteger(Val);
44    S = N.getAsString();
45
46    if (ModLen == 9 && !memcmp(Modifier, "objcclass", 9) && ArgLen == 0)
47      S = '+' + S;
48    else if (ModLen == 12 && !memcmp(Modifier, "objcinstance", 12) && ArgLen==0)
49      S = '-' + S;
50    else
51      assert(ModLen == 0 && ArgLen == 0 &&
52             "Invalid modifier for DeclarationName argument");
53  }
54  Output.append(S.begin(), S.end());
55}
56
57
58static inline RecordDecl *CreateStructDecl(ASTContext &C, const char *Name) {
59  if (C.getLangOptions().CPlusPlus)
60    return CXXRecordDecl::Create(C, TagDecl::TK_struct,
61                                 C.getTranslationUnitDecl(),
62                                 SourceLocation(), &C.Idents.get(Name));
63
64  return RecordDecl::Create(C, TagDecl::TK_struct,
65                            C.getTranslationUnitDecl(),
66                            SourceLocation(), &C.Idents.get(Name));
67}
68
69void Sema::ActOnTranslationUnitScope(SourceLocation Loc, Scope *S) {
70  TUScope = S;
71  PushDeclContext(S, Context.getTranslationUnitDecl());
72  if (!PP.getLangOptions().ObjC1) return;
73
74  // Synthesize "typedef struct objc_selector *SEL;"
75  RecordDecl *SelTag = CreateStructDecl(Context, "objc_selector");
76  PushOnScopeChains(SelTag, TUScope);
77
78  QualType SelT = Context.getPointerType(Context.getTagDeclType(SelTag));
79  TypedefDecl *SelTypedef = TypedefDecl::Create(Context, CurContext,
80                                                SourceLocation(),
81                                                &Context.Idents.get("SEL"),
82                                                SelT, 0);
83  PushOnScopeChains(SelTypedef, TUScope);
84  Context.setObjCSelType(SelTypedef);
85
86  // FIXME: Make sure these don't leak!
87  RecordDecl *ClassTag = CreateStructDecl(Context, "objc_class");
88  QualType ClassT = Context.getPointerType(Context.getTagDeclType(ClassTag));
89  TypedefDecl *ClassTypedef =
90    TypedefDecl::Create(Context, CurContext, SourceLocation(),
91                        &Context.Idents.get("Class"), ClassT, 0);
92  PushOnScopeChains(ClassTag, TUScope);
93  PushOnScopeChains(ClassTypedef, TUScope);
94  Context.setObjCClassType(ClassTypedef);
95  // Synthesize "@class Protocol;
96  ObjCInterfaceDecl *ProtocolDecl =
97    ObjCInterfaceDecl::Create(Context, SourceLocation(),
98                              &Context.Idents.get("Protocol"),
99                              SourceLocation(), true);
100  Context.setObjCProtoType(Context.getObjCInterfaceType(ProtocolDecl));
101  PushOnScopeChains(ProtocolDecl, TUScope);
102
103  // Synthesize "typedef struct objc_object { Class isa; } *id;"
104  RecordDecl *ObjectTag = CreateStructDecl(Context, "objc_object");
105
106  QualType ObjT = Context.getPointerType(Context.getTagDeclType(ObjectTag));
107  PushOnScopeChains(ObjectTag, TUScope);
108  TypedefDecl *IdTypedef = TypedefDecl::Create(Context, CurContext,
109                                               SourceLocation(),
110                                               &Context.Idents.get("id"),
111                                               ObjT, 0);
112  PushOnScopeChains(IdTypedef, TUScope);
113  Context.setObjCIdType(IdTypedef);
114}
115
116Sema::Sema(Preprocessor &pp, ASTContext &ctxt, ASTConsumer &consumer)
117  : PP(pp), Context(ctxt), Consumer(consumer), Diags(PP.getDiagnostics()),
118    SourceMgr(PP.getSourceManager()), CurContext(0), PreDeclaratorDC(0),
119    CurBlock(0), PackContext(0), IdResolver(pp.getLangOptions()),
120    GlobalNewDeleteDeclared(false) {
121
122  // Get IdentifierInfo objects for known functions for which we
123  // do extra checking.
124  IdentifierTable &IT = PP.getIdentifierTable();
125
126  KnownFunctionIDs[id_printf]        = &IT.get("printf");
127  KnownFunctionIDs[id_fprintf]       = &IT.get("fprintf");
128  KnownFunctionIDs[id_sprintf]       = &IT.get("sprintf");
129  KnownFunctionIDs[id_sprintf_chk]   = &IT.get("__builtin___sprintf_chk");
130  KnownFunctionIDs[id_snprintf]      = &IT.get("snprintf");
131  KnownFunctionIDs[id_snprintf_chk]  = &IT.get("__builtin___snprintf_chk");
132  KnownFunctionIDs[id_asprintf]      = &IT.get("asprintf");
133  KnownFunctionIDs[id_NSLog]         = &IT.get("NSLog");
134  KnownFunctionIDs[id_vsnprintf]     = &IT.get("vsnprintf");
135  KnownFunctionIDs[id_vasprintf]     = &IT.get("vasprintf");
136  KnownFunctionIDs[id_vfprintf]      = &IT.get("vfprintf");
137  KnownFunctionIDs[id_vsprintf]      = &IT.get("vsprintf");
138  KnownFunctionIDs[id_vsprintf_chk]  = &IT.get("__builtin___vsprintf_chk");
139  KnownFunctionIDs[id_vsnprintf]     = &IT.get("vsnprintf");
140  KnownFunctionIDs[id_vsnprintf_chk] = &IT.get("__builtin___vsnprintf_chk");
141  KnownFunctionIDs[id_vprintf]       = &IT.get("vprintf");
142
143  StdNamespace = 0;
144  TUScope = 0;
145  if (getLangOptions().CPlusPlus)
146    FieldCollector.reset(new CXXFieldCollector());
147
148  // Tell diagnostics how to render things from the AST library.
149  PP.getDiagnostics().SetArgToStringFn(ConvertArgToStringFn);
150}
151
152/// ImpCastExprToType - If Expr is not of type 'Type', insert an implicit cast.
153/// If there is already an implicit cast, merge into the existing one.
154  /// If isLvalue, the result of the cast is an lvalue.
155void Sema::ImpCastExprToType(Expr *&Expr, QualType Ty, bool isLvalue) {
156  QualType ExprTy = Context.getCanonicalType(Expr->getType());
157  QualType TypeTy = Context.getCanonicalType(Ty);
158
159  if (ExprTy == TypeTy)
160    return;
161
162  if (Expr->getType().getTypePtr()->isPointerType() &&
163      Ty.getTypePtr()->isPointerType()) {
164    QualType ExprBaseType =
165      cast<PointerType>(ExprTy.getUnqualifiedType())->getPointeeType();
166    QualType BaseType =
167      cast<PointerType>(TypeTy.getUnqualifiedType())->getPointeeType();
168    if (ExprBaseType.getAddressSpace() != BaseType.getAddressSpace()) {
169      Diag(Expr->getExprLoc(), diag::err_implicit_pointer_address_space_cast)
170        << Expr->getSourceRange();
171    }
172  }
173
174  if (ImplicitCastExpr *ImpCast = dyn_cast<ImplicitCastExpr>(Expr)) {
175    ImpCast->setType(Ty);
176    ImpCast->setLvalueCast(isLvalue);
177  } else
178    Expr = new ImplicitCastExpr(Ty, Expr, isLvalue);
179}
180
181void Sema::DeleteExpr(ExprTy *E) {
182  static_cast<Expr*>(E)->Destroy(Context);
183}
184void Sema::DeleteStmt(StmtTy *S) {
185  static_cast<Stmt*>(S)->Destroy(Context);
186}
187
188/// ActOnEndOfTranslationUnit - This is called at the very end of the
189/// translation unit when EOF is reached and all but the top-level scope is
190/// popped.
191void Sema::ActOnEndOfTranslationUnit() {
192
193}
194
195
196//===----------------------------------------------------------------------===//
197// Helper functions.
198//===----------------------------------------------------------------------===//
199
200const LangOptions &Sema::getLangOptions() const {
201  return PP.getLangOptions();
202}
203
204/// getCurFunctionDecl - If inside of a function body, this returns a pointer
205/// to the function decl for the function being parsed.  If we're currently
206/// in a 'block', this returns the containing context.
207FunctionDecl *Sema::getCurFunctionDecl() {
208  DeclContext *DC = CurContext;
209  while (isa<BlockDecl>(DC))
210    DC = DC->getParent();
211  return dyn_cast<FunctionDecl>(DC);
212}
213
214ObjCMethodDecl *Sema::getCurMethodDecl() {
215  DeclContext *DC = CurContext;
216  while (isa<BlockDecl>(DC))
217    DC = DC->getParent();
218  return dyn_cast<ObjCMethodDecl>(DC);
219}
220
221NamedDecl *Sema::getCurFunctionOrMethodDecl() {
222  DeclContext *DC = CurContext;
223  while (isa<BlockDecl>(DC))
224    DC = DC->getParent();
225  if (isa<ObjCMethodDecl>(DC) || isa<FunctionDecl>(DC))
226    return cast<ScopedDecl>(DC);
227  return 0;
228}
229
230