Beginning of the Great Exception Handling Rewrite.

* Add a "landing pad" attribute to the BasicBlock.
* Modify the bitcode reader and writer to handle said attribute.

Later: The verifier will ensure that the landing pad attribute is used in the
appropriate manner. I.e., not applied to the entry block, and applied only to
basic blocks that are branched to via a `dispatch' instruction.

(This is a work-in-progress.)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129235 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 29 insertions, 0 deletions

diff --git a/test/Feature/bb_attrs.ll b/test/Feature/bb_attrs.ll
new file mode 100644
index 0000000000..af2af31d69
--- /dev/null
+++ b/test/Feature/bb_attrs.ll
@@ -0,0 +1,29 @@
+; RUN: llvm-as < %s | llvm-dis > %t1.ll
+; RUN: llvm-as %t1.ll -o - | llvm-dis > %t2.ll
+; RUN: diff %t1.ll %t2.ll
+
+; Test for basic block attributes.
+
+define i32 @f1(i32 %a) {
+entry:
+  %cmp = icmp slt i32 %a, 37
+  br i1 %cmp, label %bb, label %lpad
+
+bb:
+  ret i32 37
+
+lpad: landingpad
+  ret i32 927
+}
+
+define i32 @f2(i32 %a) {
+; entry : 0
+  %1 = icmp slt i32 %a, 37
+  br i1 %1, label %2, label %3
+
+; bb : 2
+  ret i32 37
+
+landingpad ; bb : 3
+  ret i32 927
+}