1 //===--- ASTDiagnostic.cpp - Diagnostic Printing Hooks for AST Nodes ------===//
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 a diagnostic formatting hook for AST elements.
11 //
12 //===----------------------------------------------------------------------===//
13 #include "clang/AST/ASTDiagnostic.h"
14
15 #include "clang/AST/ASTContext.h"
16 #include "clang/AST/DeclObjC.h"
17 #include "clang/AST/Type.h"
18 #include "llvm/Support/raw_ostream.h"
19
20 using namespace clang;
21
22 // Returns a desugared version of the QualType, and marks ShouldAKA as true
23 // whenever we remove significant sugar from the type.
Desugar(ASTContext & Context,QualType QT,bool & ShouldAKA)24 static QualType Desugar(ASTContext &Context, QualType QT, bool &ShouldAKA) {
25 QualifierCollector QC;
26
27 while (true) {
28 const Type *Ty = QC.strip(QT);
29
30 // Don't aka just because we saw an elaborated type...
31 if (const ElaboratedType *ET = dyn_cast<ElaboratedType>(Ty)) {
32 QT = ET->desugar();
33 continue;
34 }
35 // ... or a paren type ...
36 if (const ParenType *PT = dyn_cast<ParenType>(Ty)) {
37 QT = PT->desugar();
38 continue;
39 }
40 // ...or a substituted template type parameter ...
41 if (const SubstTemplateTypeParmType *ST =
42 dyn_cast<SubstTemplateTypeParmType>(Ty)) {
43 QT = ST->desugar();
44 continue;
45 }
46 // ...or an attributed type...
47 if (const AttributedType *AT = dyn_cast<AttributedType>(Ty)) {
48 QT = AT->desugar();
49 continue;
50 }
51 // ... or an auto type.
52 if (const AutoType *AT = dyn_cast<AutoType>(Ty)) {
53 if (!AT->isSugared())
54 break;
55 QT = AT->desugar();
56 continue;
57 }
58
59 // Don't desugar template specializations, unless it's an alias template.
60 if (const TemplateSpecializationType *TST
61 = dyn_cast<TemplateSpecializationType>(Ty))
62 if (!TST->isTypeAlias())
63 break;
64
65 // Don't desugar magic Objective-C types.
66 if (QualType(Ty,0) == Context.getObjCIdType() ||
67 QualType(Ty,0) == Context.getObjCClassType() ||
68 QualType(Ty,0) == Context.getObjCSelType() ||
69 QualType(Ty,0) == Context.getObjCProtoType())
70 break;
71
72 // Don't desugar va_list.
73 if (QualType(Ty,0) == Context.getBuiltinVaListType())
74 break;
75
76 // Otherwise, do a single-step desugar.
77 QualType Underlying;
78 bool IsSugar = false;
79 switch (Ty->getTypeClass()) {
80 #define ABSTRACT_TYPE(Class, Base)
81 #define TYPE(Class, Base) \
82 case Type::Class: { \
83 const Class##Type *CTy = cast<Class##Type>(Ty); \
84 if (CTy->isSugared()) { \
85 IsSugar = true; \
86 Underlying = CTy->desugar(); \
87 } \
88 break; \
89 }
90 #include "clang/AST/TypeNodes.def"
91 }
92
93 // If it wasn't sugared, we're done.
94 if (!IsSugar)
95 break;
96
97 // If the desugared type is a vector type, we don't want to expand
98 // it, it will turn into an attribute mess. People want their "vec4".
99 if (isa<VectorType>(Underlying))
100 break;
101
102 // Don't desugar through the primary typedef of an anonymous type.
103 if (const TagType *UTT = Underlying->getAs<TagType>())
104 if (const TypedefType *QTT = dyn_cast<TypedefType>(QT))
105 if (UTT->getDecl()->getTypedefNameForAnonDecl() == QTT->getDecl())
106 break;
107
108 // Record that we actually looked through an opaque type here.
109 ShouldAKA = true;
110 QT = Underlying;
111 }
112
113 // If we have a pointer-like type, desugar the pointee as well.
114 // FIXME: Handle other pointer-like types.
115 if (const PointerType *Ty = QT->getAs<PointerType>()) {
116 QT = Context.getPointerType(Desugar(Context, Ty->getPointeeType(),
117 ShouldAKA));
118 } else if (const LValueReferenceType *Ty = QT->getAs<LValueReferenceType>()) {
119 QT = Context.getLValueReferenceType(Desugar(Context, Ty->getPointeeType(),
120 ShouldAKA));
121 } else if (const RValueReferenceType *Ty = QT->getAs<RValueReferenceType>()) {
122 QT = Context.getRValueReferenceType(Desugar(Context, Ty->getPointeeType(),
123 ShouldAKA));
124 }
125
126 return QC.apply(Context, QT);
127 }
128
129 /// \brief Convert the given type to a string suitable for printing as part of
130 /// a diagnostic.
131 ///
132 /// There are four main criteria when determining whether we should have an
133 /// a.k.a. clause when pretty-printing a type:
134 ///
135 /// 1) Some types provide very minimal sugar that doesn't impede the
136 /// user's understanding --- for example, elaborated type
137 /// specifiers. If this is all the sugar we see, we don't want an
138 /// a.k.a. clause.
139 /// 2) Some types are technically sugared but are much more familiar
140 /// when seen in their sugared form --- for example, va_list,
141 /// vector types, and the magic Objective C types. We don't
142 /// want to desugar these, even if we do produce an a.k.a. clause.
143 /// 3) Some types may have already been desugared previously in this diagnostic.
144 /// if this is the case, doing another "aka" would just be clutter.
145 /// 4) Two different types within the same diagnostic have the same output
146 /// string. In this case, force an a.k.a with the desugared type when
147 /// doing so will provide additional information.
148 ///
149 /// \param Context the context in which the type was allocated
150 /// \param Ty the type to print
151 /// \param QualTypeVals pointer values to QualTypes which are used in the
152 /// diagnostic message
153 static std::string
ConvertTypeToDiagnosticString(ASTContext & Context,QualType Ty,const DiagnosticsEngine::ArgumentValue * PrevArgs,unsigned NumPrevArgs,ArrayRef<intptr_t> QualTypeVals)154 ConvertTypeToDiagnosticString(ASTContext &Context, QualType Ty,
155 const DiagnosticsEngine::ArgumentValue *PrevArgs,
156 unsigned NumPrevArgs,
157 ArrayRef<intptr_t> QualTypeVals) {
158 // FIXME: Playing with std::string is really slow.
159 bool ForceAKA = false;
160 QualType CanTy = Ty.getCanonicalType();
161 std::string S = Ty.getAsString(Context.getPrintingPolicy());
162 std::string CanS = CanTy.getAsString(Context.getPrintingPolicy());
163
164 for (unsigned I = 0, E = QualTypeVals.size(); I != E; ++I) {
165 QualType CompareTy =
166 QualType::getFromOpaquePtr(reinterpret_cast<void*>(QualTypeVals[I]));
167 if (CompareTy.isNull())
168 continue;
169 if (CompareTy == Ty)
170 continue; // Same types
171 QualType CompareCanTy = CompareTy.getCanonicalType();
172 if (CompareCanTy == CanTy)
173 continue; // Same canonical types
174 std::string CompareS = CompareTy.getAsString(Context.getPrintingPolicy());
175 bool aka;
176 QualType CompareDesugar = Desugar(Context, CompareTy, aka);
177 std::string CompareDesugarStr =
178 CompareDesugar.getAsString(Context.getPrintingPolicy());
179 if (CompareS != S && CompareDesugarStr != S)
180 continue; // The type string is different than the comparison string
181 // and the desugared comparison string.
182 std::string CompareCanS =
183 CompareCanTy.getAsString(Context.getPrintingPolicy());
184
185 if (CompareCanS == CanS)
186 continue; // No new info from canonical type
187
188 ForceAKA = true;
189 break;
190 }
191
192 // Check to see if we already desugared this type in this
193 // diagnostic. If so, don't do it again.
194 bool Repeated = false;
195 for (unsigned i = 0; i != NumPrevArgs; ++i) {
196 // TODO: Handle ak_declcontext case.
197 if (PrevArgs[i].first == DiagnosticsEngine::ak_qualtype) {
198 void *Ptr = (void*)PrevArgs[i].second;
199 QualType PrevTy(QualType::getFromOpaquePtr(Ptr));
200 if (PrevTy == Ty) {
201 Repeated = true;
202 break;
203 }
204 }
205 }
206
207 // Consider producing an a.k.a. clause if removing all the direct
208 // sugar gives us something "significantly different".
209 if (!Repeated) {
210 bool ShouldAKA = false;
211 QualType DesugaredTy = Desugar(Context, Ty, ShouldAKA);
212 if (ShouldAKA || ForceAKA) {
213 if (DesugaredTy == Ty) {
214 DesugaredTy = Ty.getCanonicalType();
215 }
216 std::string akaStr = DesugaredTy.getAsString(Context.getPrintingPolicy());
217 if (akaStr != S) {
218 S = "'" + S + "' (aka '" + akaStr + "')";
219 return S;
220 }
221 }
222 }
223
224 S = "'" + S + "'";
225 return S;
226 }
227
FormatASTNodeDiagnosticArgument(DiagnosticsEngine::ArgumentKind Kind,intptr_t Val,const char * Modifier,unsigned ModLen,const char * Argument,unsigned ArgLen,const DiagnosticsEngine::ArgumentValue * PrevArgs,unsigned NumPrevArgs,SmallVectorImpl<char> & Output,void * Cookie,ArrayRef<intptr_t> QualTypeVals)228 void clang::FormatASTNodeDiagnosticArgument(
229 DiagnosticsEngine::ArgumentKind Kind,
230 intptr_t Val,
231 const char *Modifier,
232 unsigned ModLen,
233 const char *Argument,
234 unsigned ArgLen,
235 const DiagnosticsEngine::ArgumentValue *PrevArgs,
236 unsigned NumPrevArgs,
237 SmallVectorImpl<char> &Output,
238 void *Cookie,
239 ArrayRef<intptr_t> QualTypeVals) {
240 ASTContext &Context = *static_cast<ASTContext*>(Cookie);
241
242 std::string S;
243 bool NeedQuotes = true;
244
245 switch (Kind) {
246 default: llvm_unreachable("unknown ArgumentKind");
247 case DiagnosticsEngine::ak_qualtype: {
248 assert(ModLen == 0 && ArgLen == 0 &&
249 "Invalid modifier for QualType argument");
250
251 QualType Ty(QualType::getFromOpaquePtr(reinterpret_cast<void*>(Val)));
252 S = ConvertTypeToDiagnosticString(Context, Ty, PrevArgs, NumPrevArgs,
253 QualTypeVals);
254 NeedQuotes = false;
255 break;
256 }
257 case DiagnosticsEngine::ak_declarationname: {
258 DeclarationName N = DeclarationName::getFromOpaqueInteger(Val);
259 S = N.getAsString();
260
261 if (ModLen == 9 && !memcmp(Modifier, "objcclass", 9) && ArgLen == 0)
262 S = '+' + S;
263 else if (ModLen == 12 && !memcmp(Modifier, "objcinstance", 12)
264 && ArgLen==0)
265 S = '-' + S;
266 else
267 assert(ModLen == 0 && ArgLen == 0 &&
268 "Invalid modifier for DeclarationName argument");
269 break;
270 }
271 case DiagnosticsEngine::ak_nameddecl: {
272 bool Qualified;
273 if (ModLen == 1 && Modifier[0] == 'q' && ArgLen == 0)
274 Qualified = true;
275 else {
276 assert(ModLen == 0 && ArgLen == 0 &&
277 "Invalid modifier for NamedDecl* argument");
278 Qualified = false;
279 }
280 const NamedDecl *ND = reinterpret_cast<const NamedDecl*>(Val);
281 ND->getNameForDiagnostic(S, Context.getPrintingPolicy(), Qualified);
282 break;
283 }
284 case DiagnosticsEngine::ak_nestednamespec: {
285 llvm::raw_string_ostream OS(S);
286 reinterpret_cast<NestedNameSpecifier*>(Val)->print(OS,
287 Context.getPrintingPolicy());
288 NeedQuotes = false;
289 break;
290 }
291 case DiagnosticsEngine::ak_declcontext: {
292 DeclContext *DC = reinterpret_cast<DeclContext *> (Val);
293 assert(DC && "Should never have a null declaration context");
294
295 if (DC->isTranslationUnit()) {
296 // FIXME: Get these strings from some localized place
297 if (Context.getLangOpts().CPlusPlus)
298 S = "the global namespace";
299 else
300 S = "the global scope";
301 } else if (TypeDecl *Type = dyn_cast<TypeDecl>(DC)) {
302 S = ConvertTypeToDiagnosticString(Context,
303 Context.getTypeDeclType(Type),
304 PrevArgs, NumPrevArgs, QualTypeVals);
305 } else {
306 // FIXME: Get these strings from some localized place
307 NamedDecl *ND = cast<NamedDecl>(DC);
308 if (isa<NamespaceDecl>(ND))
309 S += "namespace ";
310 else if (isa<ObjCMethodDecl>(ND))
311 S += "method ";
312 else if (isa<FunctionDecl>(ND))
313 S += "function ";
314
315 S += "'";
316 ND->getNameForDiagnostic(S, Context.getPrintingPolicy(), true);
317 S += "'";
318 }
319 NeedQuotes = false;
320 break;
321 }
322 }
323
324 if (NeedQuotes)
325 Output.push_back('\'');
326
327 Output.append(S.begin(), S.end());
328
329 if (NeedQuotes)
330 Output.push_back('\'');
331 }
332