Verifier: Check that @llvm.dbg.* intrinsics have a !dbg attachment

Before we start to rely on valid `!dbg` attachments, add a check to the
verifier that `@llvm.dbg.*` intrinsics always have one.  Also check that
the `scope:` fields point at the same `MDSubprogram`.

This is in the context of PR22778.  The check that the `inlinedAt:`
fields agree has baked for a while (since r234021), so I'll kill [1] the
`MDLocalVariable::getInlinedAt()` field soon.

[1]: http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20150330/269387.html

Unfortunately, that means it's impossible to keep the current `Verifier`
checks, which rely on comparing `inlinedAt:` fields.  We'll be able to
keep the checks I'm adding here.

If this breaks your out-of-tree testcases, the upgrade script
(add-dbg-to-intrinsics.sh) attached to PR22778 that I used for r235040
might fix them for you.

llvm-svn: 235048

1 files changed, 2 insertions, 1 deletions

diff --git a/llvm/test/Verifier/llvm.dbg.declare-variable.ll b/llvm/test/Verifier/llvm.dbg.declare-variable.ll
index e038243bdd6..763f4637366 100644
--- a/llvm/test/Verifier/llvm.dbg.declare-variable.ll
+++ b/llvm/test/Verifier/llvm.dbg.declare-variable.ll
@@ -6,7 +6,7 @@
 define void @foo(i32 %a) {
 entry:
   %s = alloca i32
-  call void @llvm.dbg.declare(metadata i32* %s, metadata !"", metadata !MDExpression())
+  call void @llvm.dbg.declare(metadata i32* %s, metadata !"", metadata !MDExpression()), !dbg !MDLocation(scope: !1)
   ret void
 }
 
@@ -14,3 +14,4 @@ declare void @llvm.dbg.declare(metadata, metadata, metadata)
 
 !llvm.module.flags = !{!0}
 !0 = !{i32 2, !"Debug Info Version", i32 3}
+!1 = !MDSubprogram()