From 004e95174d0161ba92ca7e0f055462a2aeef05fa Mon Sep 17 00:00:00 2001
From: Saleem Abdulrasool <compnerd@compnerd.org>
Date: Tue, 27 Jun 2017 18:37:51 +0000
Subject: [PATCH] CodeGen: load indirect ObjC ARC arguments in prologue

When generating a prologue, add loads for ARC arguments passed
indirectly.

Patch by Dave Lee!

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@306444 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/CGDecl.cpp             |  4 ++++
 test/CodeGenObjCXX/arc-indirect.mm | 21 +++++++++++++++++++++
 2 files changed, 25 insertions(+)
 create mode 100644 test/CodeGenObjCXX/arc-indirect.mm

diff --git a/lib/CodeGen/CGDecl.cpp b/lib/CodeGen/CGDecl.cpp
index ccd3b8d513..4b656ea4a8 100644
--- a/lib/CodeGen/CGDecl.cpp
+++ b/lib/CodeGen/CGDecl.cpp
@@ -1860,6 +1860,10 @@ void CodeGenFunction::EmitParmDecl(const VarDecl &D, ParamValue Arg,
         lt = Qualifiers::OCL_ExplicitNone;
       }
 
+      // Load objects passed indirectly.
+      if (Arg.isIndirect() && !ArgVal)
+        ArgVal = Builder.CreateLoad(DeclPtr);
+
       if (lt == Qualifiers::OCL_Strong) {
         if (!isConsumed) {
           if (CGM.getCodeGenOpts().OptimizationLevel == 0) {
diff --git a/test/CodeGenObjCXX/arc-indirect.mm b/test/CodeGenObjCXX/arc-indirect.mm
new file mode 100644
index 0000000000..2684e82e2e
--- /dev/null
+++ b/test/CodeGenObjCXX/arc-indirect.mm
@@ -0,0 +1,21 @@
+// RUN: %clang_cc1 -std=c++11 -triple i686-unknown-windows-msvc -fobjc-runtime=gnustep -fobjc-arc -Wno-objc-root-class -emit-llvm -o - %s | FileCheck -check-prefixes CHECK,CHECK-GNUSTEP %s
+// RUN: %clang_cc1 -std=c++11 -triple i686-unknown-windows-msvc -fobjc-runtime=macosx -fobjc-arc -Wno-objc-root-class -emit-llvm -o - %s | FileCheck -check-prefixes CHECK,CHECK-DARWIN %s
+// RUN: %clang_cc1 -std=c++11 -triple i686-unknown-windows-msvc -fobjc-runtime=ios -fobjc-arc -Wno-objc-root-class -emit-llvm -o - %s | FileCheck -check-prefixes CHECK,CHECK-DARWIN %s
+
+// non trivially copyable, forces inalloca
+struct S {
+  S(const S &s) {}
+};
+
+@interface C
+@end
+@implementation C
+- (void)object:(id)obj struct:(S)s {
+}
+@end
+
+// CHECK-GNUSTEP: define internal void @_i_C__object_struct_(<{ %0*, i8*, i8*, %struct.S, [3 x i8] }>* inalloca)
+// CHECK-DARWIN: define internal void @"\01-[C object:struct:]"(<{ %0*, i8*, i8*, %struct.S, [3 x i8] }>* inalloca)
+// CHECK: %obj = getelementptr inbounds <{ %0*, i8*, i8*, %struct.S, [3 x i8] }>, <{ %0*, i8*, i8*, %struct.S, [3 x i8] }>* %0, i32 0, i32 2
+// CHECK: %1 = load i8*, i8** %obj, align 4
+// CHECK: call void @objc_storeStrong(i8** %obj, i8* %1)
-- 
2.40.0