path: root/lib/Lex/Pragma.cpp

//===--- Pragma.cpp - Pragma registration and handling --------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the PragmaHandler/PragmaTable interfaces and implements
// pragma related methods of the Preprocessor class.
//
//===----------------------------------------------------------------------===//

#include "clang/Lex/Pragma.h"
#include "clang/Lex/HeaderSearch.h"
#include "clang/Lex/LiteralSupport.h"
#include "clang/Lex/Preprocessor.h"
#include "clang/Lex/MacroInfo.h"
#include "clang/Lex/LexDiagnostic.h"
#include "clang/Basic/FileManager.h"
#include "clang/Basic/SourceManager.h"
#include "llvm/Support/CrashRecoveryContext.h"
#include "llvm/Support/ErrorHandling.h"
#include <algorithm>
using namespace clang;

// Out-of-line destructor to provide a home for the class.
PragmaHandler::~PragmaHandler() {
}

//===----------------------------------------------------------------------===//
// EmptyPragmaHandler Implementation.
//===----------------------------------------------------------------------===//

EmptyPragmaHandler::EmptyPragmaHandler() {}

void EmptyPragmaHandler::HandlePragma(Preprocessor &PP, 
                                      PragmaIntroducerKind Introducer,
                                      Token &FirstToken) {}

//===----------------------------------------------------------------------===//
// PragmaNamespace Implementation.
//===----------------------------------------------------------------------===//


PragmaNamespace::~PragmaNamespace() {
  for (llvm::StringMap<PragmaHandler*>::iterator
         I = Handlers.begin(), E = Handlers.end(); I != E; ++I)
    delete I->second;
}

/// FindHandler - Check to see if there is already a handler for the
/// specified name.  If not, return the handler for the null identifier if it
/// exists, otherwise return null.  If IgnoreNull is true (the default) then
/// the null handler isn't returned on failure to match.
PragmaHandler *PragmaNamespace::FindHandler(StringRef Name,
                                            bool IgnoreNull) const {
  if (PragmaHandler *Handler = Handlers.lookup(Name))
    return Handler;
  return IgnoreNull ? 0 : Handlers.lookup(StringRef());
}

void PragmaNamespace::AddPragma(PragmaHandler *Handler) {
  assert(!Handlers.lookup(Handler->getName()) &&
         "A handler with this name is already registered in this namespace");
  llvm::StringMapEntry<PragmaHandler *> &Entry =
    Handlers.GetOrCreateValue(Handler->getName());
  Entry.setValue(Handler);
}

void PragmaNamespace::RemovePragmaHandler(PragmaHandler *Handler) {
  assert(Handlers.lookup(Handler->getName()) &&
         "Handler not registered in this namespace");
  Handlers.erase(Handler->getName());
}

void PragmaNamespace::HandlePragma(Preprocessor &PP, 
                                   PragmaIntroducerKind Introducer,
                                   Token &Tok) {
  // Read the 'namespace' that the directive is in, e.g. STDC.  Do not macro
  // expand it, the user can have a STDC #define, that should not affect this.
  PP.LexUnexpandedToken(Tok);

  // Get the handler for this token.  If there is no handler, ignore the pragma.
  PragmaHandler *Handler
    = FindHandler(Tok.getIdentifierInfo() ? Tok.getIdentifierInfo()->getName()
                                          : StringRef(),
                  /*IgnoreNull=*/false);
  if (Handler == 0) {
    PP.Diag(Tok, diag::warn_pragma_ignored);
    return;
  }

  // Otherwise, pass it down.
  Handler->HandlePragma(PP, Introducer, Tok);
}

//===----------------------------------------------------------------------===//
// Preprocessor Pragma Directive Handling.
//===----------------------------------------------------------------------===//

/// HandlePragmaDirective - The "#pragma" directive has been parsed.  Lex the
/// rest of the pragma, passing it to the registered pragma handlers.
void Preprocessor