Validated by nightly-test runs on x86 and x86-64 darwin, including after

self-host.  Hopefully these results hold up on different platforms.  

I tried to keep the GNU ObjC runtime happy, but it's hard for me to test.
Reimplement how clang generates IR for exceptions.  Instead of creating new
invoke destinations which sequentially chain to the previous destination,
push a more semantic representation of *why* we need the cleanup/catch/filter
behavior, then collect that information into a single landing pad upon request.

Also reorganizes how normal cleanups (i.e. cleanups triggered by non-exceptional
control flow) are generated, since it's actually fairly closely tied in with
the former.  Remove the need to track which cleanup scope a block is associated
with.

Document a lot of previously poorly-understood (by me, at least) behavior.

The new framework implements the Horrible Hack (tm), which requires every
landing pad to have a catch-all so that inlining will work.  Clang no longer
requires the Horrible Hack just to make exceptions flow correctly within
a function, however.  The HH is an unfortunate requirement of LLVM's EH IR.




git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@107631 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 25 insertions, 4 deletions

diff --git a/test/CodeGenObjC/exceptions.m b/test/CodeGenObjC/exceptions.m
index a74dee95dd..5be695932b 100644
--- a/test/CodeGenObjC/exceptions.m
+++ b/test/CodeGenObjC/exceptions.m
@@ -1,11 +1,8 @@
-// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -emit-llvm -o %t %s
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -emit-llvm -fexceptions -O2 -o - %s | FileCheck %s
 //
 // <rdar://problem/7471679> [irgen] [eh] Exception code built with clang (x86_64) crashes
 
 // Just check that we don't emit any dead blocks.
-//
-// RUN: grep 'No predecessors' %t | count 0
-
 @interface NSArray @end
 void f0() {
   @try {
@@ -16,3 +13,27 @@ void f0() {
   } @catch (id e) {
   }
 }
+
+// CHECK: define void @f1()
+void f1() {
+  extern void foo(void);
+
+  while (1) {
+    // CHECK:      call void @objc_exception_try_enter
+    // CHECK-NEXT: getelementptr
+    // CHECK-NEXT: call i32 @_setjmp(
+    // CHECK-NEXT: icmp
+    // CHECK-NEXT: br i1
+    @try {
+    // CHECK:      call void @foo()
+      foo();
+    // CHECK:      call void @objc_exception_try_exit
+    // CHECK-NEXT: ret void
+
+    // CHECK:      call i8* @objc_exception_extract
+    // CHECK-NEXT: ret void
+    } @finally {
+      break;
+    }
+  }
+}