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 Whether the last diagnostic came from the "from" context.
53    bool LastDiagFromFrom;
54
55    /// \brief Mapping from the already-imported types in the "from" context
56    /// to the corresponding types in the "to" context.
57    llvm::DenseMap<const Type *, const Type *> ImportedTypes;
58
59    /// \brief Mapping from the already-imported declarations in the "from"
60    /// context to the corresponding declarations in the "to" context.
61    llvm::DenseMap<Decl *, Decl *> ImportedDecls;
62
63    /// \brief Mapping from the already-imported statements in the "from"
64    /// context to the corresponding statements in the "to" context.
65    llvm::DenseMap<Stmt *, Stmt *> ImportedStmts;
66
67    /// \brief Mapping from the already-imported FileIDs in the "from" source
68    /// manager to the corresponding FileIDs in the "to" source manager.
69    llvm::DenseMap<FileID, FileID> ImportedFileIDs;
70
71    /// \brief Imported, anonymous tag declarations that are missing their
72    /// corresponding typedefs.
73    SmallVector<TagDecl *, 4> AnonTagsWithPendingTypedefs;
74
75    /// \brief Declaration (from, to) pairs that are known not to be equivalent
76    /// (which we have already complained about).
77    NonEquivalentDeclSet NonEquivalentDecls;
78
79  public:
80    /// \brief Create a new AST importer.
81    ///
82    /// \param ToContext The context we'll be importing into.
83    ///
84    /// \param ToFileManager The file manager we'll be importing into.
85    ///
86    /// \param FromContext The context we'll be importing from.
87    ///
88    /// \param FromFileManager The file manager we'll be importing into.
89    ///
90    /// \param MinimalImport If true, the importer will attempt to import
91    /// as little as it can, e.g., by importing declarations as forward
92    /// declarations that can be completed at a later point.
93    ASTImporter(ASTContext &ToContext, FileManager &ToFileManager,
94                ASTContext &FromContext, FileManager &FromFileManager,
95                bool MinimalImport);
96
97    virtual ~ASTImporter();
98
99    /// \brief Whether the importer will perform a minimal import, creating
100    /// to-be-completed forward declarations when possible.
101    bool isMinimalImport() const { return Minimal; }
102
103    /// \brief Import the given type from the "from" context into the "to"
104    /// context.
105    ///
106    /// \returns the equivalent type in the "to" context, or a NULL type if
107    /// an error occurred.
108    QualType Import(QualType FromT);
109
110    /// \brief Import the given type source information from the
111    /// "from" context into the "to" context.
112    ///
113    /// \returns the equivalent type source information in the "to"
114    /// context, or NULL if an error occurred.
115    TypeSourceInfo *Import(TypeSourceInfo *FromTSI);
116
117    /// \brief Import the given declaration from the "from" context into the
118    /// "to" context.
119    ///
120    /// \returns the equivalent declaration in the "to" context, or a NULL type
121    /// if an error occurred.
122    Decl *Import(Decl *FromD);
123
124    /// \brief Import the given declaration context from the "from"
125    /// AST context into the "to" AST context.
126    ///
127    /// \returns the equivalent declaration context in the "to"
128    /// context, or a NULL type if an error occurred.
129    DeclContext *ImportContext(DeclContext *FromDC);
130
131    /// \brief Import the given expression from the "from" context into the
132    /// "to" context.
133    ///
134    /// \returns the equivalent expression in the "to" context, or NULL if
135    /// an error occurred.
136    Expr *Import(Expr *FromE);
137
138    /// \brief Import the given statement from the "from" context into the
139    /// "to" context.
140    ///
141    /// \returns the equivalent statement in the "to" context, or NULL if
142    /// an error occurred.
143    Stmt *Import(Stmt *FromS);
144
145    /// \brief Import the given nested-name-specifier from the "from"
146    /// context into the "to" context.
147    ///
148    /// \returns the equivalent nested-name-specifier in the "to"
149    /// context, or NULL if an error occurred.
150    NestedNameSpecifier *Import(NestedNameSpecifier *FromNNS);
151
152    /// \brief Import the given nested-name-specifier from the "from"
153    /// context into the "to" context.
154    ///
155    /// \returns the equivalent nested-name-specifier in the "to"
156    /// context.
157    NestedNameSpecifierLoc Import(NestedNameSpecifierLoc FromNNS);
158
159    /// \brief Import the goven template name from the "from" context into the
160    /// "to" context.
161    TemplateName Import(TemplateName From);
162
163    /// \brief Import the given source location from the "from" context into
164    /// the "to" context.
165    ///
166    /// \returns the equivalent source location in the "to" context, or an
167    /// invalid source location if an error occurred.
168    SourceLocation Import(SourceLocation FromLoc);
169
170    /// \brief Import the given source range from the "from" context into
171    /// the "to" context.
172    ///
173    /// \returns the equivalent source range in the "to" context, or an
174    /// invalid source location if an error occurred.
175    SourceRange Import(SourceRange FromRange);
176
177    /// \brief Import the given declaration name from the "from"
178    /// context into the "to" context.
179    ///
180    /// \returns the equivalent declaration name in the "to" context,
181    /// or an empty declaration name if an error occurred.
182    DeclarationName Import(DeclarationName FromName);
183
184    /// \brief Import the given identifier from the "from" context
185    /// into the "to" context.
186    ///
187    /// \returns the equivalent identifier in the "to" context.
188    IdentifierInfo *Import(const IdentifierInfo *FromId);
189
190    /// \brief Import the given Objective-C selector from the "from"
191    /// context into the "to" context.
192    ///
193    /// \returns the equivalent selector in the "to" context.
194    Selector Import(Selector FromSel);
195
196    /// \brief Import the given file ID from the "from" context into the
197    /// "to" context.
198    ///
199    /// \returns the equivalent file ID in the source manager of the "to"
200    /// context.
201    FileID Import(FileID);
202
203    /// \brief Import the definition of the given declaration, including all of
204    /// the declarations it contains.
205    ///
206    /// This routine is intended to be used
207    void ImportDefinition(Decl *From);
208
209    /// \brief Cope with a name conflict when importing a declaration into the
210    /// given context.
211    ///
212    /// This routine is invoked whenever there is a name conflict while
213    /// importing a declaration. The returned name will become the name of the
214    /// imported declaration. By default, the returned name is the same as the
215    /// original name, leaving the conflict unresolve such that name lookup
216    /// for this name is likely to find an ambiguity later.
217    ///
218    /// Subclasses may override this routine to resolve the conflict, e.g., by
219    /// renaming the declaration being imported.
220    ///
221    /// \param Name the name of the declaration being imported, which conflicts
222    /// with other declarations.
223    ///
224    /// \param DC the declaration context (in the "to" AST context) in which
225    /// the name is being imported.
226    ///
227    /// \param IDNS the identifier namespace in which the name will be found.
228    ///
229    /// \param Decls the set of declarations with the same name as the
230    /// declaration being imported.
231    ///
232    /// \param NumDecls the number of conflicting declarations in \p Decls.
233    ///
234    /// \returns the name that the newly-imported declaration should have.
235    virtual DeclarationName HandleNameConflict(DeclarationName Name,
236                                               DeclContext *DC,
237                                               unsigned IDNS,
238                                               NamedDecl **Decls,
239                                               unsigned NumDecls);
240
241    /// \brief Retrieve the context that AST nodes are being imported into.
242    ASTContext &getToContext() const { return ToContext; }
243
244    /// \brief Retrieve the context that AST nodes are being imported from.
245    ASTContext &getFromContext() const { return FromContext; }
246
247    /// \brief Retrieve the file manager that AST nodes are being imported into.
248    FileManager &getToFileManager() const { return ToFileManager; }
249
250    /// \brief Retrieve the file manager that AST nodes are being imported from.
251    FileManager &getFromFileManager() const { return FromFileManager; }
252
253    /// \brief Report a diagnostic in the "to" context.
254    DiagnosticBuilder ToDiag(SourceLocation Loc, unsigned DiagID);
255
256    /// \brief Report a diagnostic in the "from" context.
257    DiagnosticBuilder FromDiag(SourceLocation Loc, unsigned DiagID);
258
259    /// \brief Return the set of declarations that we know are not equivalent.
260    NonEquivalentDeclSet &getNonEquivalentDecls() { return NonEquivalentDecls; }
261
262    /// \brief Called for ObjCInterfaceDecl, ObjCProtocolDecl, and TagDecl.
263    /// Mark the Decl as complete, filling it in as much as possible.
264    ///
265    /// \param D A declaration in the "to" context.
266    virtual void CompleteDecl(Decl* D);
267
268    /// \brief Note that we have imported the "from" declaration by mapping it
269    /// to the (potentially-newly-created) "to" declaration.
270    ///
271    /// Subclasses can override this function to observe all of the \c From ->
272    /// \c To declaration mappings as they are imported.
273    virtual Decl *Imported(Decl *From, Decl *To);
274
275    /// \brief Called by StructuralEquivalenceContext.  If a RecordDecl is
276    /// being compared to another RecordDecl as part of import, completing the
277    /// other RecordDecl may trigger importation of the first RecordDecl. This
278    /// happens especially for anonymous structs.  If the original of the second
279    /// RecordDecl can be found, we can complete it without the need for
280    /// importation, eliminating this loop.
281    virtual Decl *GetOriginalDecl(Decl *To) { return nullptr; }
282
283    /// \brief Determine whether the given types are structurally
284    /// equivalent.
285    bool IsStructurallyEquivalent(QualType From, QualType To,
286                                  bool Complain = true);
287  };
288}
289
290#endif // LLVM_CLANG_AST_ASTIMPORTER_H
291