ldc/gen/passes/StripMetaData.cpp
2009-05-11 11:59:22 +02:00

84 lines
2.6 KiB
C++

//===- StripMetaData - Strips D-specific metadata -------------------------===//
//
// The LLVM D Compiler
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// There's an issue with the new LLVM metadata support; an assertion fires when
// trying to generate asm for metadata globals.
//
// This pass is a workaround; it deletes the metadata LDC generates so the code
// generator doesn't see it.
// Obviously, this should only run after all passes that make use of that
// metadata or they won't work.
//
//===----------------------------------------------------------------------===//
#include "gen/metadata.h"
// This pass isn't needed without metadata, so #ifdef it out entirely if the
// LLVM version in use doesn't support it.
#ifdef USE_METADATA
#define DEBUG_TYPE "strip-metadata"
#include "Passes.h"
#include "llvm/Pass.h"
#include "llvm/Module.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/Debug.h"
using namespace llvm;
STATISTIC(NumDeleted, "Number of metadata globals deleted");
//===----------------------------------------------------------------------===//
// StripMetaData Pass Implementation
//===----------------------------------------------------------------------===//
namespace {
/// This pass optimizes library functions from the D runtime as used by LDC.
///
class VISIBILITY_HIDDEN StripMetaData : public ModulePass {
public:
static char ID; // Pass identification
StripMetaData() : ModulePass(&ID) {}
bool runOnModule(Module &M);
};
char StripMetaData::ID = 0;
} // end anonymous namespace.
static RegisterPass<StripMetaData>
X("strip-metadata", "Delete D-specific metadata");
// Public interface to the pass.
ModulePass *createStripMetaData() {
return new StripMetaData();
}
/// runOnFunction - Top level algorithm.
///
bool StripMetaData::runOnModule(Module &M) {
bool Changed = false;
for (Module::global_iterator I = M.global_begin(), E = M.global_end(); I != E;) {
GlobalVariable* G = I++;
if (G->getNameLen() >= 9 && !strncmp(G->getNameStart(), "llvm.ldc.", 9)) {
assert(G->hasInitializer() && isa<MDNode>(G->getInitializer())
&& "Not a metadata global?");
Changed = true;
NumDeleted++;
DEBUG(DOUT << "Deleting " << *G << '\n');
G->eraseFromParent();
}
}
return Changed;
}
#endif //USE_METADATA