Sema.cpp revision 47b9a1ca55e61e37f5a368740e29de190345acc6 
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"
20using namespace clang;
21
22/// ConvertQualTypeToStringFn - This function is used to pretty print the
23/// specified QualType as a string in diagnostics.
24static void ConvertArgToStringFn(Diagnostic::ArgumentKind Kind, intptr_t Val,
25                                      const char *Modifier, unsigned ModLen,
26                                      const char *Argument, unsigned ArgLen,
27                                      llvm::SmallVectorImpl<char> &Output) {
28
29  std::string S;
30  if (Kind == Diagnostic::ak_qualtype) {
31    QualType Ty(QualType::getFromOpaquePtr(reinterpret_cast<void*>(Val)));
32
33    // FIXME: Playing with std::string is really slow.
34    S = Ty.getAsString();
35
36    assert(ModLen == 0 && ArgLen == 0 &&
37           "Invalid modifier for QualType argument");
38
39  } else if (Kind == Diagnostic::ak_declarationname) {
40
41    DeclarationName N = DeclarationName::getFromOpaqueInteger(Val);
42    S = N.getAsString();
43
44    if (ModLen == 9 && !memcmp(Modifier, "objcclass", 9) && ArgLen == 0)
45      S = '+' + S;
46    else if (ModLen == 12 && !memcmp(Modifier, "objcinstance", 12) && ArgLen==0)
47      S = '-' + S;
48    else
49      assert(ModLen == 0 && ArgLen == 0 &&
50             "Invalid modifier for DeclarationName argument");
51  } else {
52    assert(Kind == Diagnostic::ak_nameddecl);
53    assert(ModLen == 1 && Modifier[0] == 'q' && ArgLen == 0 &&
54           "Invalid modifier for NamedDecl* argument");
55
56    S = reinterpret_cast<NamedDecl*>(Val)->getQualifiedNameAsString();
57
58  }
59  Output.append(S.begin(), S.end());
60}
61
62
63static inline RecordDecl *CreateStructDecl(ASTContext &C, const char *Name) {
64  if (C.getLangOptions().CPlusPlus)
65    return CXXRecordDecl::Create(C, TagDecl::TK_struct,
66                                 C.getTranslationUnitDecl(),
67                                 SourceLocation(), &C.Idents.get(Name));
68
69  return RecordDecl::Create(C, TagDecl::TK_struct,
70                            C.getTranslationUnitDecl(),
71                            SourceLocation(), &C.Idents.get(Name));
72}
73
74void Sema::ActOnTranslationUnitScope(SourceLocation Loc, Scope *S) {
75  TUScope = S;
76  PushDeclContext(S, Context.getTranslationUnitDecl());
77  if (!PP.getLangOptions().ObjC1) return;
78
79  // Synthesize "typedef struct objc_selector *SEL;"
80  RecordDecl *SelTag = CreateStructDecl(Context, "objc_selector");
81  PushOnScopeChains(SelTag, TUScope);
82
83  QualType SelT = Context.getPointerType(Context.getTagDeclType(SelTag));
84  TypedefDecl *SelTypedef = TypedefDecl::Create(Context, CurContext,
85                                                SourceLocation(),
86                                                &Context.Idents.get("SEL"),
87                                                SelT);
88  PushOnScopeChains(SelTypedef, TUScope);
89  Context.setObjCSelType(SelTypedef);
90
91  // FIXME: Make sure these don't leak!
92  RecordDecl *ClassTag = CreateStructDecl(Context, "objc_class");
93  QualType ClassT = Context.getPointerType(Context.getTagDeclType(ClassTag));
94  TypedefDecl *ClassTypedef =
95    TypedefDecl::Create(Context, CurContext, SourceLocation(),
96                        &Context.Idents.get("Class"), ClassT);
97  PushOnScopeChains(ClassTag, TUScope);
98  PushOnScopeChains(ClassTypedef, TUScope);
99  Context.setObjCClassType(ClassTypedef);
100  // Synthesize "@class Protocol;
101  ObjCInterfaceDecl *ProtocolDecl =
102    ObjCInterfaceDecl::Create(Context, CurContext, SourceLocation(),
103                              &Context.Idents.get("Protocol"),
104                              SourceLocation(), true);
105  Context.setObjCProtoType(Context.getObjCInterfaceType(ProtocolDecl));
106  PushOnScopeChains(ProtocolDecl, TUScope);
107
108  // Synthesize "typedef struct objc_object { Class isa; } *id;"
109  RecordDecl *ObjectTag = CreateStructDecl(Context, "objc_object");
110
111  QualType ObjT = Context.getPointerType(Context.getTagDeclType(ObjectTag));
112  PushOnScopeChains(ObjectTag, TUScope);
113  TypedefDecl *IdTypedef = TypedefDecl::Create(Context, CurContext,
114                                               SourceLocation(),
115                                               &Context.Idents.get("id"),
116                                               ObjT);
117  PushOnScopeChains(IdTypedef, TUScope);
118  Context.setObjCIdType(IdTypedef);
119}
120
121Sema::Sema(Preprocessor &pp, ASTContext &ctxt, ASTConsumer &consumer)
122  : LangOpts(pp.getLangOptions()), PP(pp), Context(ctxt), Consumer(consumer),
123    Diags(PP.getDiagnostics()),
124    SourceMgr(PP.getSourceManager()), CurContext(0), PreDeclaratorDC(0),
125    CurBlock(0), PackContext(0), IdResolver(pp.getLangOptions()),
126    GlobalNewDeleteDeclared(false) {
127
128  // Get IdentifierInfo objects for known functions for which we
129  // do extra checking.
130  IdentifierTable &IT = PP.getIdentifierTable();
131
132  KnownFunctionIDs[id_printf]        = &IT.get("printf");
133  KnownFunctionIDs[id_fprintf]       = &IT.get("fprintf");
134  KnownFunctionIDs[id_sprintf]       = &IT.get("sprintf");
135  KnownFunctionIDs[id_sprintf_chk]   = &IT.get("__builtin___sprintf_chk");
136  KnownFunctionIDs[id_snprintf]      = &IT.get("snprintf");
137  KnownFunctionIDs[id_snprintf_chk]  = &IT.get("__builtin___snprintf_chk");
138  KnownFunctionIDs[id_asprintf]      = &IT.get("asprintf");
139  KnownFunctionIDs[id_NSLog]         = &IT.get("NSLog");
140  KnownFunctionIDs[id_vsnprintf]     = &IT.get("vsnprintf");
141  KnownFunctionIDs[id_vasprintf]     = &IT.get("vasprintf");
142  KnownFunctionIDs[id_vfprintf]      = &IT.get("vfprintf");
143  KnownFunctionIDs[id_vsprintf]      = &IT.get("vsprintf");
144  KnownFunctionIDs[id_vsprintf_chk]  = &IT.get("__builtin___vsprintf_chk");
145  KnownFunctionIDs[id_vsnprintf]     = &IT.get("vsnprintf");
146  KnownFunctionIDs[id_vsnprintf_chk] = &IT.get("__builtin___vsnprintf_chk");
147  KnownFunctionIDs[id_vprintf]       = &IT.get("vprintf");
148
149  StdNamespace = 0;
150  TUScope = 0;
151  if (getLangOptions().CPlusPlus)
152    FieldCollector.reset(new CXXFieldCollector());
153
154  // Tell diagnostics how to render things from the AST library.
155  PP.getDiagnostics().SetArgToStringFn(ConvertArgToStringFn);
156}
157
158/// ImpCastExprToType - If Expr is not of type 'Type', insert an implicit cast.
159/// If there is already an implicit cast, merge into the existing one.
160/// If isLvalue, the result of the cast is an lvalue.
161void Sema::ImpCastExprToType(Expr *&Expr, QualType Ty, bool isLvalue) {
162  QualType ExprTy = Context.getCanonicalType(Expr->getType());
163  QualType TypeTy = Context.getCanonicalType(Ty);
164
165  if (ExprTy == TypeTy)
166    return;
167
168  if (Expr->getType().getTypePtr()->isPointerType() &&
169      Ty.getTypePtr()->isPointerType()) {
170    QualType ExprBaseType =
171      cast<PointerType>(ExprTy.getUnqualifiedType())->getPointeeType();
172    QualType BaseType =
173      cast<PointerType>(TypeTy.getUnqualifiedType())->getPointeeType();
174    if (ExprBaseType.getAddressSpace() != BaseType.getAddressSpace()) {
175      Diag(Expr->getExprLoc(), diag::err_implicit_pointer_address_space_cast)
176        << Expr->getSourceRange();
177    }
178  }
179
180  if (ImplicitCastExpr *ImpCast = dyn_cast<ImplicitCastExpr>(Expr)) {
181    ImpCast->setType(Ty);
182    ImpCast->setLvalueCast(isLvalue);
183  } else
184    Expr = new ImplicitCastExpr(Ty, Expr, isLvalue);
185}
186
187void Sema::DeleteExpr(ExprTy *E) {
188  if (E) static_cast<Expr*>(E)->Destroy(Context);
189}
190void Sema::DeleteStmt(StmtTy *S) {
191  if (S) static_cast<Stmt*>(S)->Destroy(Context);
192}
193
194/// ActOnEndOfTranslationUnit - This is called at the very end of the
195/// translation unit when EOF is reached and all but the top-level scope is
196/// popped.
197void Sema::ActOnEndOfTranslationUnit() {
198
199}
200
201
202//===----------------------------------------------------------------------===//
203// Helper functions.
204//===----------------------------------------------------------------------===//
205
206/// getCurFunctionDecl - If inside of a function body, this returns a pointer
207/// to the function decl for the function being parsed.  If we're currently
208/// in a 'block', this returns the containing context.
209FunctionDecl *Sema::getCurFunctionDecl() {
210  DeclContext *DC = CurContext;
211  while (isa<BlockDecl>(DC))
212    DC = DC->getParent();
213  return dyn_cast<FunctionDecl>(DC);
214}
215
216ObjCMethodDecl *Sema::getCurMethodDecl() {
217  DeclContext *DC = CurContext;
218  while (isa<BlockDecl>(DC))
219    DC = DC->getParent();
220  return dyn_cast<ObjCMethodDecl>(DC);
221}
222
223NamedDecl *Sema::getCurFunctionOrMethodDecl() {
224  DeclContext *DC = CurContext;
225  while (isa<BlockDecl>(DC))
226    DC = DC->getParent();
227  if (isa<ObjCMethodDecl>(DC) || isa<FunctionDecl>(DC))
228    return cast<NamedDecl>(DC);
229  return 0;
230}
231
232