NeXT/EH: When generating the rethrow code for a finally block, make sure to

chain outwards when inside a nested exception scope.
 - A real test for this is going into LLVM test-suite.

llvm-svn: 102204

2 files changed, 30 insertions, 2 deletions

diff --git a/clang/lib/CodeGen/CGObjCMac.cpp b/clang/lib/CodeGen/CGObjCMac.cpp
index e8c08056304..421136ba47e 100644
--- a/clang/lib/CodeGen/CGObjCMac.cpp
+++ b/clang/lib/CodeGen/CGObjCMac.cpp
@@ -5772,9 +5772,19 @@ CGObjCNonFragileABIMac::EmitTryOrSynchronizedStmt(CodeGen::CodeGenFunction &CGF,
   // Branch around the rethrow code.
   CGF.EmitBranch(FinallyEnd);
 
+  // Generate the rethrow code, taking care to use an invoke if we are in a
+  // nested exception scope.
   CGF.EmitBlock(FinallyRethrow);
-  CGF.Builder.CreateCall(ObjCTypes.getUnwindResumeOrRethrowFn(),
-                         CGF.Builder.CreateLoad(RethrowPtr));
+  if (PrevLandingPad) {
+    llvm::BasicBlock *Cont = CGF.createBasicBlock("invoke.cont");
+    CGF.Builder.CreateInvoke(ObjCTypes.getUnwindResumeOrRethrowFn(),
+                             Cont, PrevLandingPad,
+                             CGF.Builder.CreateLoad(RethrowPtr));
+    CGF.EmitBlock(Cont);
+  } else {
+    CGF.Builder.CreateCall(ObjCTypes.getUnwindResumeOrRethrowFn(),
+                           CGF.Builder.CreateLoad(RethrowPtr));
+  }
   CGF.Builder.CreateUnreachable();
 
   CGF.EmitBlock(FinallyEnd);
diff --git a/clang/test/CodeGenObjC/exceptions.m b/clang/test/CodeGenObjC/exceptions.m
new file mode 100644
index 00000000000..a74dee95dda
--- /dev/null
+++ b/clang/test/CodeGenObjC/exceptions.m
@@ -0,0 +1,18 @@
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -emit-llvm -o %t %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 {
+    @try {
+      @throw @"a";
+    } @catch(NSArray *e) {
+    }
+  } @catch (id e) {
+  }
+}