Refactor stripDebugInfo(Function) to handle intrinsic

This moves the code that handles stripping debug info intrinsic from
 StripDebugInfo(Module) to StripDebugInfo(Function). The latter is
already walking every instructions so it makes sense to do it at the
same time.
This makes also stripDebugInfo(Function) as an API more useful: it
is really dropping every debug info in the Function.
Finally the existing code is trigerring an assertion when the Module
is not fully materialized.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 268832

1 files changed, 13 insertions, 21 deletions

diff --git a/llvm/lib/IR/DebugInfo.cpp b/llvm/lib/IR/DebugInfo.cpp
index e8c62961eba..18ec7cdfdba 100644
--- a/llvm/lib/IR/DebugInfo.cpp
+++ b/llvm/lib/IR/DebugInfo.cpp
@@ -247,8 +247,20 @@ bool llvm::stripDebugInfo(Function &F) {
     Changed = true;
     F.setSubprogram(nullptr);
   }
+
+  Function *Declare = F.getParent()->getFunction("llvm.dbg.declare");
+  Function *DbgVal = F.getParent()->getFunction("llvm.dbg.value");
   for (BasicBlock &BB : F) {
-    for (Instruction &I : BB) {
+    for (auto II = BB.begin(), End = BB.end(); II != End;) {
+      Instruction &I = *II++; // We may delete the instruction, increment now.
+      // Remove all of the calls to the debugger intrinsics, and remove them
+      // from the module.
+      CallInst *CI = dyn_cast<CallInst>(&I);
+      if (CI && (CI->getCalledFunction() == Declare ||
+                 CI->getCalledFunction() == DbgVal)) {
+        CI->eraseFromParent();
+        Changed = true;
+      }
       if (I.getDebugLoc()) {
         Changed = true;
         I.setDebugLoc(DebugLoc());
@@ -261,26 +273,6 @@ bool llvm::stripDebugInfo(Function &F) {
 bool llvm::StripDebugInfo(Module &M) {
   bool Changed = false;
 
-  // Remove all of the calls to the debugger intrinsics, and remove them from
-  // the module.
-  if (Function *Declare = M.getFunction("llvm.dbg.declare")) {
-    while (!Declare->use_empty()) {
-      CallInst *CI = cast<CallInst>(Declare->user_back());
-      CI->eraseFromParent();
-    }
-    Declare->eraseFromParent();
-    Changed = true;
-  }
-
-  if (Function *DbgVal = M.getFunction("llvm.dbg.value")) {
-    while (!DbgVal->use_empty()) {
-      CallInst *CI = cast<CallInst>(DbgVal->user_back());
-      CI->eraseFromParent();
-    }
-    DbgVal->eraseFromParent();
-    Changed = true;
-  }
-
   for (Module::named_metadata_iterator NMI = M.named_metadata_begin(),
          NME = M.named_metadata_end(); NMI != NME;) {
     NamedMDNode *NMD = &*NMI;