1 //===--- NestedNameSpecifier.cpp - C++ nested name specifiers -----*- C++ -*-=//
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 defines the NestedNameSpecifier class, which represents
11 //  a C++ nested-name-specifier.
12 //
13 //===----------------------------------------------------------------------===//
14 #include "clang/AST/NestedNameSpecifier.h"
15 #include "clang/AST/ASTContext.h"
16 #include "clang/AST/Decl.h"
17 #include "clang/AST/PrettyPrinter.h"
18 #include "clang/AST/Type.h"
19 #include "llvm/Support/raw_ostream.h"
20 #include <cassert>
21 
22 using namespace clang;
23 
24 NestedNameSpecifier *
25 NestedNameSpecifier::FindOrInsert(ASTContext &Context,
26                                   const NestedNameSpecifier &Mockup) {
27   llvm::FoldingSetNodeID ID;
28   Mockup.Profile(ID);
29 
30   void *InsertPos = 0;
31   NestedNameSpecifier *NNS
32     = Context.NestedNameSpecifiers.FindNodeOrInsertPos(ID, InsertPos);
33   if (!NNS) {
34     NNS = new (Context, 4) NestedNameSpecifier(Mockup);
35     Context.NestedNameSpecifiers.InsertNode(NNS, InsertPos);
36   }
37 
38   return NNS;
39 }
40 
41 NestedNameSpecifier *
42 NestedNameSpecifier::Create(ASTContext &Context, NestedNameSpecifier *Prefix,
43                             IdentifierInfo *II) {
44   assert(II && "Identifier cannot be NULL");
45   assert((!Prefix || Prefix->isDependent()) && "Prefix must be dependent");
46 
47   NestedNameSpecifier Mockup;
48   Mockup.Prefix.setPointer(Prefix);
49   Mockup.Prefix.setInt(Identifier);
50   Mockup.Specifier = II;
51   return FindOrInsert(Context, Mockup);
52 }
53 
54 NestedNameSpecifier *
55 NestedNameSpecifier::Create(ASTContext &Context, NestedNameSpecifier *Prefix,
56                             NamespaceDecl *NS) {
57   assert(NS && "Namespace cannot be NULL");
58   assert((!Prefix ||
59           (Prefix->getAsType() == 0 && Prefix->getAsIdentifier() == 0)) &&
60          "Broken nested name specifier");
61   NestedNameSpecifier Mockup;
62   Mockup.Prefix.setPointer(Prefix);
63   Mockup.Prefix.setInt(Namespace);
64   Mockup.Specifier = NS;
65   return FindOrInsert(Context, Mockup);
66 }
67 
68 NestedNameSpecifier *
69 NestedNameSpecifier::Create(ASTContext &Context, NestedNameSpecifier *Prefix,
70                             bool Template, Type *T) {
71   assert(T && "Type cannot be NULL");
72   NestedNameSpecifier Mockup;
73   Mockup.Prefix.setPointer(Prefix);
74   Mockup.Prefix.setInt(Template? TypeSpecWithTemplate : TypeSpec);
75   Mockup.Specifier = T;
76   return FindOrInsert(Context, Mockup);
77 }
78 
79 NestedNameSpecifier *
80 NestedNameSpecifier::Create(ASTContext &Context, IdentifierInfo *II) {
81   assert(II && "Identifier cannot be NULL");
82   NestedNameSpecifier Mockup;
83   Mockup.Prefix.setPointer(0);
84   Mockup.Prefix.setInt(Identifier);
85   Mockup.Specifier = II;
86   return FindOrInsert(Context, Mockup);
87 }
88 
89 NestedNameSpecifier *NestedNameSpecifier::GlobalSpecifier(ASTContext &Context) {
90   if (!Context.GlobalNestedNameSpecifier)
91     Context.GlobalNestedNameSpecifier = new (Context, 4) NestedNameSpecifier();
92   return Context.GlobalNestedNameSpecifier;
93 }
94 
95 /// \brief Whether this nested name specifier refers to a dependent
96 /// type or not.
97 bool NestedNameSpecifier::isDependent() const {
98   switch (getKind()) {
99   case Identifier:
100     // Identifier specifiers always represent dependent types
101     return true;
102 
103   case Namespace:
104   case Global:
105     return false;
106 
107   case TypeSpec:
108   case TypeSpecWithTemplate:
109     return getAsType()->isDependentType();
110   }
111 
112   // Necessary to suppress a GCC warning.
113   return false;
114 }
115 
116 /// \brief Print this nested name specifier to the given output
117 /// stream.
118 void
119 NestedNameSpecifier::print(llvm::raw_ostream &OS,
120                            const PrintingPolicy &Policy) const {
121   if (getPrefix())
122     getPrefix()->print(OS, Policy);
123 
124   switch (getKind()) {
125   case Identifier:
126     OS << getAsIdentifier()->getName();
127     break;
128 
129   case Namespace:
130     OS << getAsNamespace()->getIdentifier()->getName();
131     break;
132 
133   case Global:
134     break;
135 
136   case TypeSpecWithTemplate:
137     OS << "template ";
138     // Fall through to print the type.
139 
140   case TypeSpec: {
141     std::string TypeStr;
142     Type *T = getAsType();
143 
144     PrintingPolicy InnerPolicy(Policy);
145     InnerPolicy.SuppressScope = true;
146 
147     // Nested-name-specifiers are intended to contain minimally-qualified
148     // types. An actual ElaboratedType will not occur, since we'll store
149     // just the type that is referred to in the nested-name-specifier (e.g.,
150     // a TypedefType, TagType, etc.). However, when we are dealing with
151     // dependent template-id types (e.g., Outer<T>::template Inner<U>),
152     // the type requires its own nested-name-specifier for uniqueness, so we
153     // suppress that nested-name-specifier during printing.
154     assert(!isa<ElaboratedType>(T) &&
155            "Elaborated type in nested-name-specifier");
156     if (const TemplateSpecializationType *SpecType
157           = dyn_cast<TemplateSpecializationType>(T)) {
158       // Print the template name without its corresponding
159       // nested-name-specifier.
160       SpecType->getTemplateName().print(OS, InnerPolicy, true);
161 
162       // Print the template argument list.
163       TypeStr = TemplateSpecializationType::PrintTemplateArgumentList(
164                                                           SpecType->getArgs(),
165                                                        SpecType->getNumArgs(),
166                                                                  InnerPolicy);
167     } else {
168       // Print the type normally
169       TypeStr = QualType(T, 0).getAsString(InnerPolicy);
170     }
171     OS << TypeStr;
172     break;
173   }
174   }
175 
176   OS << "::";
177 }
178 
179 void NestedNameSpecifier::Destroy(ASTContext &Context) {
180   this->~NestedNameSpecifier();
181   Context.Deallocate((void *)this);
182 }
183 
184 void NestedNameSpecifier::dump(const LangOptions &LO) {
185   print(llvm::errs(), PrintingPolicy(LO));
186 }
187