From 5e5974f51ad079a3ed890ca8be1d3f50150320ad Mon Sep 17 00:00:00 2001
From: Manman Ren <mren@apple.com>
Date: Wed, 27 Feb 2013 02:11:57 +0000
Subject: [PATCH] SelectionDAG: If llvm.donothing has a landingpad, we should
 clear CurrentCallSite to avoid an assertion failure:
 assert(MMI.getCurrentCallSite() == 0 && "Overlapping call sites!");

rdar://problem/13228754


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176154 91177308-0d34-0410-b5e6-96231b3b80d8
---
 .../SelectionDAG/SelectionDAGBuilder.cpp      |  7 ++++
 test/CodeGen/ARM/invoke-donothing-assert.ll   | 40 +++++++++++++++++++
 2 files changed, 47 insertions(+)
 create mode 100644 test/CodeGen/ARM/invoke-donothing-assert.ll

diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index b8ab2a9c1bc..e3c2c2e8ef5 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -1872,6 +1872,13 @@ void SelectionDAGBuilder::visitInvoke(const InvokeInst &I) {
     visitInlineAsm(&I);
   else if (Fn && Fn->isIntrinsic()) {
     assert(Fn->getIntrinsicID() == Intrinsic::donothing);
+    // If donothing has a landingpad, we should clear CurrentCallSite.
+    if (LandingPad) {
+      MachineModuleInfo &MMI = DAG.getMachineFunction().getMMI();
+      unsigned CallSiteIndex = MMI.getCurrentCallSite();
+      if (CallSiteIndex)
+        MMI.setCurrentCallSite(0);
+    }
     // Ignore invokes to @llvm.donothing: jump directly to the next BB.
   } else
     LowerCallTo(&I, getValue(Callee), false, LandingPad);
diff --git a/test/CodeGen/ARM/invoke-donothing-assert.ll b/test/CodeGen/ARM/invoke-donothing-assert.ll
new file mode 100644
index 00000000000..d0c98f80289
--- /dev/null
+++ b/test/CodeGen/ARM/invoke-donothing-assert.ll
@@ -0,0 +1,40 @@
+; RUN: llc < %s -mtriple=armv7-apple-ios | FileCheck %s
+; This testcase makes sure we can handle invoke @llvm.donothing without
+; assertion failure.
+; rdar://problem/13228754
+; CHECK: .globl  _main
+
+declare void @callA()
+declare i32 @__gxx_personality_sj0(...)
+
+define void @main() {
+invoke.cont:
+  invoke void @callA() 
+          to label %invoke.cont25 unwind label %lpad2
+invoke.cont25:
+  invoke void @llvm.donothing()
+          to label %invoke.cont27 unwind label %lpad15
+
+invoke.cont27:
+  invoke void @callB()
+          to label %invoke.cont75 unwind label %lpad15
+
+invoke.cont75:
+  ret void
+
+lpad2:
+  %0 = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__gxx_personality_sj0 to i8*)
+          cleanup
+  br label %eh.resume
+
+lpad15:
+  %1 = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__gxx_personality_sj0 to i8*)
+          cleanup
+  br label %eh.resume
+
+eh.resume:
+  resume { i8*, i32 } zeroinitializer
+}
+
+declare void @callB()
+declare void @llvm.donothing() nounwind readnone