[llvm-commits] CVS: llvm/lib/Transforms/IPO/StripDeadPrototypes.cpp

[Reid Spencer]

Changes in directory llvm/lib/Transforms/IPO:

StripDeadPrototypes.cpp added (r1.1)
---
Log message:

Create a pass to strip dead function declarations (prototypes). This is
for use by llvm-extract and bugpoint.


---
Diffs of the changes:  (+61 -0)

 StripDeadPrototypes.cpp |   61 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 61 insertions(+)


Index: llvm/lib/Transforms/IPO/StripDeadPrototypes.cpp
diff -c /dev/null llvm/lib/Transforms/IPO/StripDeadPrototypes.cpp:1.1
*** /dev/null	Mon Feb  5 14:24:35 2007
--- llvm/lib/Transforms/IPO/StripDeadPrototypes.cpp	Mon Feb  5 14:24:25 2007
***************
*** 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();
+ }