ASTImporter.h revision ac32ff9812e7d6bc31573b5499bfd005fc8b8f39 
1//===--- ASTImporter.h - Importing ASTs from other Contexts -----*- 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 ASTImporter class which imports AST nodes from one
11//  context into another context.
12//
13//===----------------------------------------------------------------------===//
14#ifndef LLVM_CLANG_AST_ASTIMPORTER_H
15#define LLVM_CLANG_AST_ASTIMPORTER_H
16
17#include "clang/AST/DeclarationName.h"
18#include "clang/AST/Type.h"
19#include "clang/Basic/SourceLocation.h"
20#include "llvm/ADT/DenseMap.h"
21#include "llvm/ADT/DenseSet.h"
22#include "llvm/ADT/SmallVector.h"
23
24namespace clang {
25  class ASTContext;
26  class Decl;
27  class DeclContext;
28  class DiagnosticsEngine;
29  class Expr;
30  class FileManager;
31  class IdentifierInfo;
32  class NestedNameSpecifier;
33  class Stmt;
34  class TypeSourceInfo;
35
36  /// \brief Imports selected nodes from one AST context into another context,
37  /// merging AST nodes where appropriate.
38  class ASTImporter {
39  public:
40    typedef llvm::DenseSet<std::pair<Decl *, Decl *> > NonEquivalentDeclSet;
41
42  private:
43    /// \brief The contexts we're importing to and from.
44    ASTContext &ToContext, &FromContext;
45
46    /// \brief The file managers we're importing to and from.
47    FileManager &ToFileManager, &FromFileManager;
48
49    /// \brief Whether to perform a minimal import.
50    bool Minimal;
51
52    /// \brief Mapping from the already-imported types in the "from" context
53    /// to the corresponding types in the "to" context.
54    llvm::DenseMap<const Type *, const Type *> ImportedTypes;
55
56    /// \brief Mapping from the already-imported declarations in the "from"
57    /// context to the corresponding declarations in the "to" context.
58    llvm::DenseMap<Decl *, Decl *> ImportedDecls;
59
60    /// \brief Mapping from the already-imported statements in the "from"
61    /// context to the corresponding statements in the "to" context.
62    llvm::DenseMap<Stmt *, Stmt *> ImportedStmts;
63
64    /// \brief Mapping from the already-imported FileIDs in the "from" source
65    /// manager to the corresponding FileIDs in the "to" source manager.
66    llvm::DenseMap<FileID, FileID> ImportedFileIDs;
67
68    /// \brief Imported, anonymous tag declarations that are missing their
69    /// corresponding typedefs.
70    SmallVector<TagDecl *, 4> AnonTagsWithPendingTypedefs;
71
72    /// \brief Declaration (from, to) pairs that are known not to be equivalent
73    /// (which we have already complained about).
74    NonEquivalentDeclSet NonEquivalentDecls;
75
76  public:
77    /// \brief Create a new AST importer.
78    ///
79    /// \param ToContext The context we'll be importing into.
80    ///
81    /// \param ToFileManager The file manager we'll be importing into.
82    ///
83    /// \param FromContext The context we'll be importing from.
84    ///
85    /// \param FromFileManager The file manager we'll be importing into.
86    ///
87    /// \param MinimalImport If true, the importer will attempt to import
88    /// as little as it can, e.g., by importing declarations as forward
89    /// declarations that can be completed at a later point.
90    ASTImporter(ASTContext &ToContext, FileManager &ToFileManager,
91                ASTContext &FromContext, FileManager &FromFileManager,
92                bool MinimalImport);
93
94    virtual ~ASTImporter();
95
96    /// \brief Whether the importer will perform a minimal import, creating
97    /// to-be-completed forward declarations when possible.
98    bool isMinimalImport() const { return Minimal; }
99
100    /// \brief Import the given type from the "from" context into the "to"
101    /// context.
102    ///
103    /// \returns the equivalent type in the "to" context, or a NULL type if
104    /// an error occurred.
105    QualType Import(QualType FromT);
106
107    /// \brief Import the given type source information from the
108    /// "from" context into the "to" context.
109    ///
110    /// \returns the equivalent type source information in the "to"
111    /// context, or NULL if an error occurred.
112    TypeSourceInfo *Import(TypeSourceInfo *FromTSI);
113
114    /// \brief Import the given declaration from the "from" context into the
115    /// "to" context.
116    ///
117    /// \returns the equivalent declaration in the "to" context, or a NULL type
118    /// if an error occurred.
119    Decl *Import(Decl *FromD);
120
121    /// \brief Import the given declaration context from the "from"
122    /// AST context into the "to" AST context.
123    ///
124    /// \returns the equivalent declaration context in the "to"
125    /// context, or a NULL type if an error occurred.
126    DeclContext *ImportContext(DeclContext *FromDC);
127
128    /// \brief Import the given expression from the "from" context into the
129    /// "to" context.
130    ///
131    /// \returns the equivalent expression in the "to" context, or NULL if
132    /// an error occurred.
133    Expr *Import(Expr *FromE);
134
135    /// \brief Import the given statement from the "from" context into the
136    /// "to" context.
137    ///
138    /// \returns the equivalent statement in the "to" context, or NULL if
139    /// an error occurred.
140    Stmt *Import(Stmt *FromS);
141
142    /// \brief Import the given nested-name-specifier from the "from"
143    /// context into the "to" context.
144    ///
145    /// \returns the equivalent nested-name-specifier in the "to"
146    /// context, or NULL if an error occurred.
147    NestedNameSpecifier *Import(NestedNameSpecifier *FromNNS);
148
149    /// \brief Import the given nested-name-specifier from the "from"
150    /// context into the "to" context.
151    ///
152    /// \returns the equivalent nested-name-specifier in the "to"
153    /// context.
154    NestedNameSpecifierLoc Import(NestedNameSpecifierLoc FromNNS);
155
156    /// \brief Import the goven template name from the "from" context into the
157    /// "to" context.
158    TemplateName Import(TemplateName From);
159
160    /// \brief Import the given source location from the "from" context into
161    /// the "to" context.
162    ///
163    /// \returns the equivalent source location in the "to" context, or an
164    /// invalid source location if an error occurred.
165    SourceLocation Import(SourceLocation FromLoc);
166
167    /// \brief Import the given source range from the "from" context into
168    /// the "to" context.
169    ///
170    /// \returns the equivalent source range in the "to" context, or an
171    /// invalid source location if an error occurred.
172    SourceRange Import(SourceRange FromRange);
173
174    /// \brief Import the given declaration name from the "from"
175    /// context into the "to" context.
176    ///
177    /// \returns the equivalent declaration name in the "to" context,
178    /// or an empty declaration name if an error occurred.
179    DeclarationName Import(DeclarationName FromName);
180
181    /// \brief Import the given identifier from the "from" context
182    /// into the "to" context.
183    ///
184    /// \returns the equivalent identifier in the "to" context.
185    IdentifierInfo *Import(const IdentifierInfo *FromId);
186
187    /// \brief Import the given Objective-C selector from the "from"
188    /// context into the "to" context.
189    ///
190    /// \returns the equivalent selector in the "to" context.
191    Selector Import(Selector FromSel);
192
193    /// \brief Import the given file ID from the "from" context into the
194    /// "to" context.
195    ///
196    /// \returns the equivalent file ID in the source manager of the "to"
197    /// context.
198    FileID Import(FileID);
199
200    /// \brief Import the definition of the given declaration, including all of
201    /// the declarations it contains.
202    ///
203    /// This routine is intended to be used
204    void ImportDefinition(Decl *From);
205
206    /// \brief Cope with a name conflict when importing a declaration into the
207    /// given context.
208    ///
209    /// This routine is invoked whenever there is a name conflict while
210    /// importing a declaration. The returned name will become the name of the
211    /// imported declaration. By default, the returned name is the same as the
212    /// original name, leaving the conflict unresolve such that name lookup
213    /// for this name is likely to find an ambiguity later.
214    ///
215    /// Subclasses may override this routine to resolve the conflict, e.g., by
216    /// renaming the declaration being imported.
217    ///
218    /// \param Name the name of the declaration being imported, which conflicts
219    /// with other declarations.
220    ///
221    /// \param DC the declaration context (in the "to" AST context) in which
222    /// the name is being imported.
223    ///
224    /// \param IDNS the identifier namespace in which the name will be found.
225    ///
226    /// \param Decls the set of declarations with the same name as the
227    /// declaration being imported.
228    ///
229    /// \param NumDecls the number of conflicting declarations in \p Decls.
230    ///
231    /// \returns the name that the newly-imported declaration should have.
232    virtual DeclarationName HandleNameConflict(DeclarationName Name,
233                                               DeclContext *DC,
234                                               unsigned IDNS,
235                                               NamedDecl **Decls,
236                                               unsigned NumDecls);
237
238    /// \brief Retrieve the context that AST nodes are being imported into.
239    ASTContext &getToContext() const { return ToContext; }
240
241    /// \brief Retrieve the context that AST nodes are being imported from.
242    ASTContext &getFromContext() const { return FromContext; }
243
244    /// \brief Retrieve the file manager that AST nodes are being imported into.
245    FileManager &getToFileManager() const { return ToFileManager; }
246
247    /// \brief Retrieve the file manager that AST nodes are being imported from.
248    FileManager &getFromFileManager() const { return FromFileManager; }
249
250    /// \brief Report a diagnostic in the "to" context.
251    DiagnosticBuilder ToDiag(SourceLocation Loc, unsigned DiagID);
252
253    /// \brief Report a diagnostic in the "from" context.
254    DiagnosticBuilder FromDiag(SourceLocation Loc, unsigned DiagID);
255
256    /// \brief Return the set of declarations that we know are not equivalent.
257    NonEquivalentDeclSet &getNonEquivalentDecls() { return NonEquivalentDecls; }
258
259    /// \brief Called for ObjCInterfaceDecl, ObjCProtocolDecl, and TagDecl.
260    /// Mark the Decl as complete, filling it in as much as possible.
261    ///
262    /// \param D A declaration in the "to" context.
263    virtual void CompleteDecl(Decl* D);
264
265    /// \brief Note that we have imported the "from" declaration by mapping it
266    /// to the (potentially-newly-created) "to" declaration.
267    ///
268    /// Subclasses can override this function to observe all of the \c From ->
269    /// \c To declaration mappings as they are imported.
270    virtual Decl *Imported(Decl *From, Decl *To);
271
272    /// \brief Determine whether the given types are structurally
273    /// equivalent.
274    bool IsStructurallyEquivalent(QualType From, QualType To);
275  };
276}
277
278#endif // LLVM_CLANG_AST_ASTIMPORTER_H
279