From 90d45b8a4a787739662dc1c781dc0e7c57c2ffa2 Mon Sep 17 00:00:00 2001
From: Devang Patel <dpatel@apple.com>
Date: Tue, 11 Nov 2008 19:33:39 +0000
Subject: [PATCH] Add utility pass to remove dbg info.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@59068 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/LinkAllPasses.h            |  1 +
 include/llvm/Transforms/IPO.h           |  7 ++
 lib/Transforms/Utils/DbgInfoRemover.cpp | 97 +++++++++++++++++++++++++
 3 files changed, 105 insertions(+)
 create mode 100644 lib/Transforms/Utils/DbgInfoRemover.cpp

diff --git a/include/llvm/LinkAllPasses.h b/include/llvm/LinkAllPasses.h
index 0d9ba26aa14..5fd9cc3312b 100644
--- a/include/llvm/LinkAllPasses.h
+++ b/include/llvm/LinkAllPasses.h
@@ -125,6 +125,7 @@ namespace {
       (void) llvm::createMergeFunctionsPass();
       (void) llvm::createPrintModulePass(0);
       (void) llvm::createPrintFunctionPass("", 0);
+      (void) llvm::createRemoveDbgInfoPass();
 
       (void)new llvm::IntervalPartition();
       (void)new llvm::FindUsedTypes();
diff --git a/include/llvm/Transforms/IPO.h b/include/llvm/Transforms/IPO.h
index 887614074c5..8c92cffa560 100644
--- a/include/llvm/Transforms/IPO.h
+++ b/include/llvm/Transforms/IPO.h
@@ -200,6 +200,13 @@ Pass *createAddReadAttrsPass();
 ///
 ModulePass *createMergeFunctionsPass();
 
+//===----------------------------------------------------------------------===//
+//
+// RemoveDbgInfoPass - This pass removes debug info. intrinsics.
+//
+ModulePass *createRemoveDbgInfoPass();
+
+
 } // End llvm namespace
 
 #endif
diff --git a/lib/Transforms/Utils/DbgInfoRemover.cpp b/lib/Transforms/Utils/DbgInfoRemover.cpp
new file mode 100644
index 00000000000..484354d7317
--- /dev/null
+++ b/lib/Transforms/Utils/DbgInfoRemover.cpp
@@ -0,0 +1,97 @@
+//===- DbgInforemover.cpp - Remove Debug Info Intrinsics ------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This is utility pass removes all debug information intrinsics from a 
+// function.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Transforms/IPO.h"
+#include "llvm/Module.h"
+#include "llvm/IntrinsicInst.h"
+#include "llvm/Pass.h"
+#include "llvm/ADT/SmallPtrSet.h"
+using namespace llvm;
+
+namespace {
+  // Remove dbg intrinsics and related globals from this module.
+  struct RemoveDbgInfoPass : public ModulePass {
+    static char ID; // Pass identification, replacement for typeid
+    RemoveDbgInfoPass() : ModulePass(&ID) {}
+    
+    void getAnalysisUsage(AnalysisUsage &Info) const {
+      Info.setPreservesCFG();
+    }
+
+    bool runOnModule(Module &M) {
+      bool Changed = false;
+      DbgGlobals.clear();
+
+      for (Module::iterator I = M.begin(), E = M.end(); I != E; ) {
+        Function *F = I++;
+        Changed |= cleanupFunction(*F);
+        if (F->hasName() && !strncmp(F->getNameStart(), "llvm.dbg", 8))
+          M.getFunctionList().erase(F);
+      }
+
+      for (Module::global_iterator GVI = M.global_begin(), E = M.global_end();
+           GVI != E; ) {
+        GlobalVariable *GV = GVI++;
+        if (GV->hasName() && !strncmp(GV->getNameStart(), "llvm.dbg", 8)) {
+          if (GV->hasInitializer())
+            CollectDbgGlobals(GV->getInitializer());
+          GV->replaceAllUsesWith(UndefValue::get(GV->getType()));
+          GV->removeDeadConstantUsers();
+          M.getGlobalList().erase(GV);
+        }
+      }
+
+      for (SmallPtrSet<GlobalVariable *,8>::iterator CI = DbgGlobals.begin(),
+             CE = DbgGlobals.end(); CI != CE; ) {
+        GlobalVariable *GV = *CI++;
+        GV->removeDeadConstantUsers();
+        if (GV->use_empty())
+          M.getGlobalList().erase(GV);
+      }
+      return Changed;
+    }
+
+    void CollectDbgGlobals(Constant *C) {
+      if (GlobalVariable *GV = dyn_cast<GlobalVariable>(C))
+        DbgGlobals.insert(GV);
+      for (User::op_iterator I = C->op_begin(), E = C->op_end(); I != E; ++I) 
+        CollectDbgGlobals(cast<Constant>(*I));
+    }
+
+    bool cleanupFunction(Function &F) {
+      SmallVector<Instruction *, 8> WorkList;
+      for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
+        for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I)
+          if (isa<DbgInfoIntrinsic>(I))
+            WorkList.push_back(I);
+
+      for (SmallVector<Instruction *, 8>::iterator WI = WorkList.begin(),
+             WE = WorkList.end(); WI != WE; ++WI)
+        (*WI)->eraseFromParent();
+     
+      return !WorkList.empty();
+    }
+    
+  private:
+    SmallPtrSet<GlobalVariable *, 8> DbgGlobals;
+  };
+  
+  char RemoveDbgInfoPass::ID = 0;
+  static RegisterPass<RemoveDbgInfoPass> X("remove-dbginfo",
+                                           "Remove Debugging Information");
+}
+
+ModulePass *llvm::createRemoveDbgInfoPass() {
+  return new RemoveDbgInfoPass();
+}
-- 
2.34.1