Verifier: Check debug info intrinsic arguments

Verify that debug info intrinsic arguments are valid.  (These checks
will not recurse through the full debug info graph, so they don't need
to be cordoned of in `DebugInfoVerifier`.)

With those checks in place, changing the `DbgIntrinsicInst` accessors to
downcast to `MDLocalVariable` and `MDExpression` is natural (added isa
specializations in `Metadata.h` to support this).

Added tests to `test/Verifier` for the new -verify checks, and fixed the
debug info in all the in-tree tests.

If you have out-of-tree testcases that have started to fail to -verify,
hopefully the verify checks are helpful.  The most likely problem is
that the expression argument is `!{}` (instead of `!MDExpression()`).

llvm-svn: 232296

1 files changed, 16 insertions, 0 deletions

diff --git a/llvm/test/Verifier/llvm.dbg.value-expression.ll b/llvm/test/Verifier/llvm.dbg.value-expression.ll
new file mode 100644
index 00000000000..c0d14a5a2c2
--- /dev/null
+++ b/llvm/test/Verifier/llvm.dbg.value-expression.ll
@@ -0,0 +1,16 @@
+; RUN: not llvm-as -disable-output <%s 2>&1 | FileCheck %s
+; CHECK: invalid llvm.dbg.value intrinsic expression
+; CHECK-NEXT: call void @llvm.dbg.value({{.*}})
+; CHECK-NEXT: !""
+
+define void @foo(i32 %a) {
+entry:
+  %s = alloca i32
+  call void @llvm.dbg.value(metadata i32* %s, i64 0, metadata !MDLocalVariable(tag: DW_TAG_arg_variable), metadata !"")
+  ret void
+}
+
+declare void @llvm.dbg.value(metadata, i64, metadata, metadata)
+
+!llvm.module.flags = !{!0}
+!0 = !{i32 2, !"Debug Info Version", i32 3}