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-rw-r--r-- | lib/Transforms/IPO/StripDeadPrototypes.cpp | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/lib/Transforms/IPO/StripDeadPrototypes.cpp b/lib/Transforms/IPO/StripDeadPrototypes.cpp new file mode 100644 index 0000000..cedaa1c --- /dev/null +++ b/lib/Transforms/IPO/StripDeadPrototypes.cpp @@ -0,0 +1,61 @@ +//===-- 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. +// +//===----------------------------------------------------------------------===// + +#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 StripDeadPrototypesPass : public ModulePass { +public: + StripDeadPrototypesPass() { } + virtual bool runOnModule(Module &M); +}; +RegisterPass<StripDeadPrototypesPass> X("strip-dead-prototypes", + "Strip Unused Function Prototypes"); + +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)); + } + + // Erase the functions + for (std::vector<Function*>::iterator I = FuncsToErase.begin(), + E = FuncsToErase.end(); I != E; ++I ) + (*I)->eraseFromParent(); + + // Increment the statistic + NumDeadPrototypes += FuncsToErase.size(); + + // Return an indication of whether we changed anything or not. + return !FuncsToErase.empty(); +} + +} // end anonymous namespace + +ModulePass *llvm::createStripDeadPrototypesPass() { + return new StripDeadPrototypesPass(); +} |