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//===-- StripDeadPrototypes.cpp - Removed unused function declarations ----===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by Reid Spencer and is distributed under the
// University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This pass loops over all of the functions in the input module, looking for
// dead declarations and removes them.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "strip-dead-prototypes"
#include "llvm/Transforms/IPO.h"
#include "llvm/Pass.h"
#include "llvm/Module.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Support/Compiler.h"
using namespace llvm;
STATISTIC(NumDeadPrototypes, "Number of dead prototypes removed");
namespace {
/// @brief Pass to remove unused function declarations.
class VISIBILITY_HIDDEN StripDeadPrototypesPass : public ModulePass {
public:
static char ID; // Pass identification, replacement for typeid
StripDeadPrototypesPass() : ModulePass((intptr_t)&ID) { }
virtual bool runOnModule(Module &M);
};
char StripDeadPrototypesPass::ID = 0;
RegisterPass<StripDeadPrototypesPass> X("strip-dead-prototypes",
"Strip Unused Function Prototypes");
} // end anonymous namespace
bool StripDeadPrototypesPass::runOnModule(Module &M) {
bool MadeChange = false;
// Erase dead function prototypes.
for (Module::iterator I = M.begin(), E = M.end(); I != E; ) {
Function *F = I++;
// Function must be a prototype and unused.
if (F->isDeclaration() && F->use_empty()) {
F->eraseFromParent();
++NumDeadPrototypes;
MadeChange = true;
}
}
// Erase dead global var prototypes.
for (Module::global_iterator I = M.global_begin(), E = M.global_end();
I != E; ) {
GlobalVariable *GV = I++;
// Global must be a prototype and unused.
if (GV->isDeclaration() && GV->use_empty())
GV->eraseFromParent();
}
// Return an indication of whether we changed anything or not.
return MadeChange;
}
ModulePass *llvm::createStripDeadPrototypesPass() {
return new StripDeadPrototypesPass();
}
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