-//===-- StripDeadPrototypes.cpp - Removed unused function declarations ----===//
+//===-- StripDeadPrototypes.cpp - Remove 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 file 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.
+// dead declarations and removes them. Dead declarations are declarations of
+// functions for which no implementation is available (i.e., declarations for
+// unused library functions).
//
//===----------------------------------------------------------------------===//
+#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/Debug.h"
-#include <vector>
using namespace llvm;
STATISTIC(NumDeadPrototypes, "Number of dead prototypes removed");
namespace {
/// @brief Pass to remove unused function declarations.
-class VISIBILITY_HIDDEN StripDeadPrototypesPass : public ModulePass {
+class StripDeadPrototypesPass : public ModulePass {
public:
- StripDeadPrototypesPass() { }
+ static char ID; // Pass identification, replacement for typeid
+ StripDeadPrototypesPass() : ModulePass(ID) { }
virtual bool runOnModule(Module &M);
};
-RegisterPass<StripDeadPrototypesPass> X("strip-dead-prototypes",
- "Strip Unused Function Prototypes");
} // end anonymous namespace
+char StripDeadPrototypesPass::ID = 0;
+INITIALIZE_PASS(StripDeadPrototypesPass, "strip-dead-prototypes",
+ "Strip Unused Function Prototypes", false, false);
+
bool StripDeadPrototypesPass::runOnModule(Module &M) {
- // Collect all the functions we want to erase
- std::vector<Function*> FuncsToErase;
- for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
- if (I->isDeclaration() && // Function must be only a prototype
- I->use_empty()) { // Function must not be used
- FuncsToErase.push_back(&(*I));
+ 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 the functions
- for (std::vector<Function*>::iterator I = FuncsToErase.begin(),
- E = FuncsToErase.end(); I != E; ++I )
- (*I)->eraseFromParent();
+ // 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();
+ }
- // Increment the statistic
- NumDeadPrototypes += FuncsToErase.size();
-
// Return an indication of whether we changed anything or not.
- return !FuncsToErase.empty();
+ return MadeChange;
}
ModulePass *llvm::createStripDeadPrototypesPass() {