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      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 
     24 namespace 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 Determine whether the given types are structurally
    276     /// equivalent.
    277     bool IsStructurallyEquivalent(QualType From, QualType To,
    278                                   bool Complain = true);
    279   };
    280 }
    281 
    282 #endif // LLVM_CLANG_AST_ASTIMPORTER_H
    283