IPO: Remove implicit ilist iterator conversions, NFC

[oota-llvm.git] / lib / Transforms / IPO / StripDeadPrototypes.cpp

diff --git a/lib/Transforms/IPO/StripDeadPrototypes.cpp b/lib/Transforms/IPO/StripDeadPrototypes.cpp
index 543c68e9ced32c488759b3bf098f3f05f71ce6a3..eba79218aed26aa6f74e7359a2ea052e1f792ba5 100644 (file)
--- a/lib/Transforms/IPO/StripDeadPrototypes.cpp
+++ b/lib/Transforms/IPO/StripDeadPrototypes.cpp
@@ -1,60 +1,72 @@
-//===-- 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).
 //
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Transforms/IPO.h"
-#include "llvm/Pass.h"
-#include "llvm/Module.h"
 #include "llvm/ADT/Statistic.h"
-#include "llvm/Support/Debug.h"
-#include "llvm/Support/Compiler.h"
-#include <vector>
+#include "llvm/IR/Module.h"
+#include "llvm/Pass.h"
 using namespace llvm;
 
+#define DEBUG_TYPE "strip-dead-prototypes"
+
 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() { }
-  virtual bool runOnModule(Module &M);
+  static char ID; // Pass identification, replacement for typeid
+  StripDeadPrototypesPass() : ModulePass(ID) {
+    initializeStripDeadPrototypesPassPass(*PassRegistry::getPassRegistry());
+  }
+  bool runOnModule(Module &M) override;
 };
-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() {