r227627 - SEH: Don't jump to an unreachable continuation block

[Reid Kleckner]

Author: rnk
Date: Fri Jan 30 16:16:45 2015
New Revision: 227627

URL: http://llvm.org/viewvc/llvm-project?rev=227627&view=rev
Log:
SEH: Don't jump to an unreachable continuation block

If both the __try and __except blocks do not return, we want to delete
the continuation block as unreachable instead.

Modified:
    cfe/trunk/lib/CodeGen/CGException.cpp
    cfe/trunk/test/CodeGen/exceptions-seh.c

Modified: cfe/trunk/lib/CodeGen/CGException.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGException.cpp?rev=227627&r1=227626&r2=227627&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGException.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGException.cpp Fri Jan 30 16:16:45 2015
@@ -1899,7 +1899,8 @@ void CodeGenFunction::ExitSEHTryStmt(con
   // Emit the __except body.
   EmitStmt(Except->getBlock());
 
-  Builder.CreateBr(ContBB);
+  if (HaveInsertPoint())
+    Builder.CreateBr(ContBB);
 
   EmitBlock(ContBB);
 }

Modified: cfe/trunk/test/CodeGen/exceptions-seh.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/exceptions-seh.c?rev=227627&r1=227626&r2=227627&view=diff
==============================================================================
--- cfe/trunk/test/CodeGen/exceptions-seh.c (original)
+++ cfe/trunk/test/CodeGen/exceptions-seh.c Fri Jan 30 16:16:45 2015
@@ -38,7 +38,7 @@ int safe_div(int numerator, int denomina
 void j(void);
 
 // FIXME: Implement local variable captures in filter expressions.
-int filter_expr_capture() {
+int filter_expr_capture(void) {
   int r = 42;
   __try {
     j();
@@ -65,7 +65,7 @@ int filter_expr_capture() {
 // FIXMECHECK: store i32 -1, i32* %{{.*}}
 // CHECK: ret i32 -1
 
-int nested_try() {
+int nested_try(void) {
   int r = 42;
   __try {
     __try {
@@ -121,7 +121,7 @@ int nested_try() {
 // FIXME: This lowering of __finally can't actually work, it will have to
 // change.
 static unsigned g = 0;
-void basic_finally() {
+void basic_finally(void) {
   ++g;
   __try {
     j();
@@ -150,3 +150,27 @@ void basic_finally() {
 // CHECK: add i32 %{{.*}}, -1
 // CHECK: store i32 %{{.*}}, i32* @g
 // CHECK: resume
+
+int returns_int(void);
+int except_return(void) {
+  __try {
+    return returns_int();
+  } __except(1) {
+    return 42;
+  }
+}
+// CHECK-LABEL: define i32 @except_return()
+// CHECK: %[[tmp:[^ ]*]] = invoke i32 @returns_int()
+// CHECK:       to label %[[cont:[^ ]*]] unwind label %[[lpad:[^ ]*]]
+//
+// CHECK: [[cont]]
+// CHECK: store i32 %[[tmp]], i32* %[[rv:[^ ]*]]
+// CHECK: br label %[[retbb:[^ ]*]]
+//
+// CHECK: [[lpad]]
+// CHECK: store i32 42, i32* %[[rv]]
+// CHECK: br label %[[retbb]]
+//
+// CHECK: [[retbb]]
+// CHECK: %[[r:[^ ]*]] = load i32* %[[rv]]
+// CHECK: ret i32 %[[r]]