Keep metadata when changing Invoke instructions to Call ones

[yrouban]

Summary

Metadata of invoke instructions get lost after SimplifyCFGPass.
Turning invokes that call 'nounwind' functions into ordinary calls the method changeToCall()
does not move or copy metadata from the source invoke instruction to the new call instruction.
This patch copies the metadata in changeToCall().

[hfinkel]

Test case?

[yrouban]

Added a new test.

[yrouban]

Decided to make use of attributes instead of metadata. Attributes are copied by most transformations.

lib/Transforms/Utils/Local.cpp

static void changeToCall(InvokeInst *II) {
   SmallVector<OperandBundleDef, 1> OpBundles;
   II->getOperandBundlesAsDefs(OpBundles);
   CallInst *NewCall = CallInst::Create(II->getCalledValue(), Args, OpBundles,
                                        "", II);
   NewCall->takeName(II);
   NewCall->setCallingConv(II->getCallingConv());
   NewCall->setAttributes(II->getAttributes());
   NewCall->setDebugLoc(II->getDebugLoc());
+  NewCall->copyMetadata(*II);
   II->replaceAllUsesWith(NewCall);
 
   // Follow the call by a branch to the normal destination.
   BranchInst::Create(II->getNormalDest(), II);
 
   // Update PHI nodes in the unwind destination
   II->getUnwindDest()->removePredecessor(II->getParent());
   II->eraseFromParent();

test/Transforms/SimplifyCFG/invoke_unwind.ll

rethrow:
   resume { i8*, i32 } %lp
   
 lpad2:
   %1 = landingpad { i8*, i32 }
           cleanup
   br label %rethrow
 }
 
+declare i32 @test4_dummy_callee()
+
+; This testcase checks to see if the simplifycfg pass converting invoke
+; instructions preserves metadata.
+define i32 @test4() personality i32 (...)* @__gxx_personality_v0 {
+; CHECK-LABEL: @test4(
+; CHECK-NEXT: call i32 @test4_dummy_callee(), !range !0, !test4_metadata !1
+; CHECK-NEXT: ret i32 %result
+        %result = invoke i32 @test4_dummy_callee( )
+                        to label %1 unwind label %Rethrow, !range !{i32 1, i32 10}, !test4_metadata !{i32 -1}
+        ret i32 %result
+Rethrow:
+        %exn = landingpad {i8*, i32}
+                 catch i8* null
+        resume { i8*, i32 } %exn
+}
+
 declare i32 @__gxx_personality_v0(...)