Add clang.arc.used to ModuleHasARC so ARC always runs if said call is present in...

clang.arc.used is an interesting call for ARC since ObjCARCContract
needs to run to remove said intrinsic to avoid a linker error (since the
call does not exist).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178369 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/ObjCARC/ObjCARC.h b/lib/Transforms/ObjCARC/ObjCARC.h
index 614fa29e3e60ffdd13b20ecbaadfdd19005bdfc5..39670f339e9f3e93334ed169333482037465d53c 100644 (file)
--- a/lib/Transforms/ObjCARC/ObjCARC.h
+++ b/lib/Transforms/ObjCARC/ObjCARC.h
@@ -64,7 +64,8 @@ static inline bool ModuleHasARC(const Module &M) {
     M.getNamedValue("objc_copyWeak") ||
     M.getNamedValue("objc_retainedObject") ||
     M.getNamedValue("objc_unretainedObject") ||
-    M.getNamedValue("objc_unretainedPointer");
+    M.getNamedValue("objc_unretainedPointer") ||
+    M.getNamedValue("clang.arc.use");
 }
 
 /// \enum InstructionClass

diff --git a/test/Transforms/ObjCARC/clang-arc-used-intrinsic-removed-if-isolated.ll b/test/Transforms/ObjCARC/clang-arc-used-intrinsic-removed-if-isolated.ll
new file mode 100644 (file)
index 0000000..4215b5c
--- /dev/null
+++ b/test/Transforms/ObjCARC/clang-arc-used-intrinsic-removed-if-isolated.ll
@@ -0,0 +1,16 @@
+; RUN: opt -objc-arc-contract -S < %s | FileCheck %s
+
+; This file makes sure that clang.arc.used is removed even if no other ARC
+; interesting calls are in the module.
+
+declare void @clang.arc.use(...) nounwind
+
+; Kill calls to @clang.arc.use(...)
+; CHECK: define void @test0(
+; CHECK-NOT: clang.arc.use
+; CHECK: }
+define void @test0(i8* %a, i8* %b) {
+  call void (...)* @clang.arc.use(i8* %a, i8* %b) nounwind
+  ret void
+}
+