Verifier: Check that inlined-at locations agree

Check that the `MDLocalVariable::getInlinedAt()` in a debug info
intrinsic's variable always matches the `MDLocation::getInlinedAt()` of
its `!dbg` attachment.

The goal here is to get rid of `MDLocalVariable::getInlinedAt()`
entirely (PR22778), since it's expensive and unnecessary, but I'll let
this verifier check bake for a while (a week maybe?) first.  I've
updated the testcases that had the wrong value for `inlinedAt:`.

This checks that things are sane in the IR, but currently things go out
of whack in a few places in the backend.  I'll follow shortly with
assertions in the backend (with code fixes).

If you have out-of-tree testcases that just started failing, here's how
I updated these ones:

 1. The verifier check gives you the basic block, function, instruction,
    and relevant metadata arguments (metadata numbering doesn't
    necessarily match the source file, unfortunately).
 2. Look at the `@llvm.dbg.*()` instruction, and compare the
    `inlinedAt:` fields of the variable argument (second `metadata`
    argument) and the `!dbg` attachment.
 3. Figure out based on the variable `scope:` chain and the functions in
    the file whether the variable has been inlined (and into what), so
    you can determine which `inlinedAt:` is actually correct.  In all of
    the in-tree testcases, the `!MDLocation()` was correct and the
    `!MDLocalVariable()` was wrong, but YMMV.
 4. Duplicate the metadata that you're going to change, and add/drop the
    `inlinedAt:` field from one of them.  Be careful that the other
    references to the same metadata node point at the correct one.

llvm-svn: 234021

1 files changed, 3 insertions, 3 deletions

diff --git a/llvm/test/Transforms/Mem2Reg/ConvertDebugInfo2.ll b/llvm/test/Transforms/Mem2Reg/ConvertDebugInfo2.ll
index e60acc4ca9b..2e7a6e6fde8 100644
--- a/llvm/test/Transforms/Mem2Reg/ConvertDebugInfo2.ll
+++ b/llvm/test/Transforms/Mem2Reg/ConvertDebugInfo2.ll
@@ -41,15 +41,15 @@ return:                                           ; preds = %entry
 !6 = !MDBasicType(tag: DW_TAG_base_type, name: "int", size: 32, align: 32, encoding: DW_ATE_signed)
 !7 = !MDLocation(line: 8, scope: !1)
 !8 = !MDLocation(line: 9, scope: !1)
-!9 = !MDLocalVariable(tag: DW_TAG_arg_variable, name: "x", line: 4, arg: 0, scope: !10, file: !2, type: !6)
+!9 = !MDLocalVariable(tag: DW_TAG_arg_variable, name: "x", line: 4, arg: 0, scope: !10, file: !2, type: !6, inlinedAt: !8)
 !10 = !MDSubprogram(name: "bar", linkageName: "bar", line: 4, isLocal: true, isDefinition: true, virtualIndex: 6, isOptimized: false, scopeLine: 4, file: !20, scope: !2, type: !11)
 !11 = !MDSubroutineType(types: !12)
 !12 = !{null, !6, !13, !14}
 !13 = !MDBasicType(tag: DW_TAG_base_type, name: "long int", size: 64, align: 64, encoding: DW_ATE_signed)
 !14 = !MDDerivedType(tag: DW_TAG_pointer_type, size: 64, align: 64, file: !20, scope: !2, baseType: null)
 !15 = !MDLocation(line: 4, scope: !10, inlinedAt: !8)
-!16 = !MDLocalVariable(tag: DW_TAG_arg_variable, name: "y", line: 4, arg: 0, scope: !10, file: !2, type: !13)
-!17 = !MDLocalVariable(tag: DW_TAG_arg_variable, name: "z", line: 4, arg: 0, scope: !10, file: !2, type: !14)
+!16 = !MDLocalVariable(tag: DW_TAG_arg_variable, name: "y", line: 4, arg: 0, scope: !10, file: !2, type: !13, inlinedAt: !8)
+!17 = !MDLocalVariable(tag: DW_TAG_arg_variable, name: "z", line: 4, arg: 0, scope: !10, file: !2, type: !14, inlinedAt: !8)
 !18 = !MDLocation(line: 5, scope: !10, inlinedAt: !8)
 !19 = !MDLocation(line: 10, scope: !1)
 !20 = !MDFile(filename: "bar.c", directory: "/tmp/")