1 //===--- Pragma.h - Pragma registration and handling ------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines the PragmaHandler and PragmaTable interfaces.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_CLANG_PRAGMA_H
15 #define LLVM_CLANG_PRAGMA_H
24 class PragmaNamespace;
26 /// PragmaHandler - Instances of this interface defined to handle the various
27 /// pragmas that the language front-end uses. Each handler optionally has a
28 /// name (e.g. "pack") and the HandlePragma method is invoked when a pragma with
29 /// that identifier is found. If a handler does not match any of the declared
30 /// pragmas the handler with a null identifier is invoked, if it exists.
32 /// Note that the PragmaNamespace class can be used to subdivide pragmas, e.g.
33 /// we treat "#pragma STDC" and "#pragma GCC" as namespaces that contain other
36 const IdentifierInfo *Name;
38 PragmaHandler(const IdentifierInfo *name) : Name(name) {}
39 virtual ~PragmaHandler();
41 const IdentifierInfo *getName() const { return Name; }
42 virtual void HandlePragma(Preprocessor &PP, Token &FirstToken) = 0;
44 /// getIfNamespace - If this is a namespace, return it. This is equivalent to
45 /// using a dynamic_cast, but doesn't require RTTI.
46 virtual PragmaNamespace *getIfNamespace() { return 0; }
49 /// PragmaNamespace - This PragmaHandler subdivides the namespace of pragmas,
50 /// allowing hierarchical pragmas to be defined. Common examples of namespaces
51 /// are "#pragma GCC", "#pragma STDC", and "#pragma omp", but any namespaces may
52 /// be (potentially recursively) defined.
53 class PragmaNamespace : public PragmaHandler {
54 /// Handlers - This is the list of handlers in this namespace.
56 std::vector<PragmaHandler*> Handlers;
58 PragmaNamespace(const IdentifierInfo *Name) : PragmaHandler(Name) {}
59 virtual ~PragmaNamespace();
61 /// FindHandler - Check to see if there is already a handler for the
62 /// specified name. If not, return the handler for the null identifier if it
63 /// exists, otherwise return null. If IgnoreNull is true (the default) then
64 /// the null handler isn't returned on failure to match.
65 PragmaHandler *FindHandler(const IdentifierInfo *Name,
66 bool IgnoreNull = true) const;
68 /// AddPragma - Add a pragma to this namespace.
70 void AddPragma(PragmaHandler *Handler) {
71 Handlers.push_back(Handler);
74 /// RemovePragmaHandler - Remove the given handler from the
76 void RemovePragmaHandler(PragmaHandler *Handler);
79 return Handlers.empty();
82 virtual void HandlePragma(Preprocessor &PP, Token &FirstToken);
84 virtual PragmaNamespace *getIfNamespace() { return this; }
88 } // end namespace clang