Rework codegen of case ranges
- Fix multiple issues with the way case ranges were emitted, see test
cases details about the specific issues.
- The root issue was not being careful about how basic blocks were
emitted which led to them being chained together incorrectly,
resulting in improper control flow.
- Fixes <rdar://problem/6098585>
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@54006 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/CodeGen/rdr-6098585-fallthrough-to-empty-range.c b/test/CodeGen/rdr-6098585-fallthrough-to-empty-range.c
new file mode 100644
index 0000000..007a0c7
--- /dev/null
+++ b/test/CodeGen/rdr-6098585-fallthrough-to-empty-range.c
@@ -0,0 +1,15 @@
+// RUN: clang --emit-llvm-bc -o - %s | opt -std-compile-opts | llvm-dis > %t &&
+// RUN: grep "ret i32 %" %t
+
+// Make sure return is not constant (if empty range is skipped or miscompiled)
+
+int f0(unsigned x) {
+ switch(x) {
+ case 2:
+ // fallthrough empty range
+ case 10 ... 9:
+ return 10;
+ default:
+ return 0;
+ }
+}