Commit Graph

6 Commits

Author SHA1 Message Date
88e419d66e DebugInfo: Remove 'inlinedAt:' field from MDLocalVariable
Remove 'inlinedAt:' from MDLocalVariable.  Besides saving some memory
(variables with it seem to be single largest `Metadata` contributer to
memory usage right now in -g -flto builds), this stops optimization and
backend passes from having to change local variables.

The 'inlinedAt:' field was used by the backend in two ways:

 1. To tell the backend whether and into what a variable was inlined.
 2. To create a unique id for each inlined variable.

Instead, rely on the 'inlinedAt:' field of the intrinsic's `!dbg`
attachment, and change the DWARF backend to use a typedef called
`InlinedVariable` which is `std::pair<MDLocalVariable*, MDLocation*>`.
This `DebugLoc` is already passed reliably through the backend (as
verified by r234021).

This commit removes the check from r234021, but I added a new check
(that will survive) in r235048, and changed the `DIBuilder` API in
r235041 to require a `!dbg` attachment whose 'scope:` is in the same
`MDSubprogram` as the variable's.

If this breaks your out-of-tree testcases, perhaps the script I used
(mdlocalvariable-drop-inlinedat.sh) will help; I'll attach it to PR22778
in a moment.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235050 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-15 22:29:27 +00:00
a9902daa5c Verifier: Check fields of MDVariable subclasses
Check fields from `MDLocalVariable` and `MDGlobalVariable` and change
the accessors to downcast to the right types.  `getType()` still returns
`Metadata*` since it could be an `MDString`-based reference.

Since local variables require non-null scopes, I also updated `LLParser`
to require a `scope:` field.

A number of testcases had grown bitrot and started failing with this
patch; I committed them separately in r233349.  If I just broke your
out-of-tree testcases, you're probably hitting similar problems (so have
a look there).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233389 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-27 17:29:58 +00:00
9b18dbfe83 Optimize metadata node fields for CHECK-ability
While gaining practical experience hand-updating CHECK lines (for moving
the new debug info hierarchy into place),  I learnt a few things about
CHECK-ability of the specialized node assembly output.

  - The first part of a `CHECK:` is to identify the "right" node (this
    is especially true if you intend to use the new `CHECK-SAME`
    feature, since the first CHECK needs to identify the node correctly
    before you can split the line).
      - If there's a `tag:`, it should go first.
      - If there's a `name:`, it should go next (followed by the
        `linkageName:`, if any).
      - If there's a `scope:`, it should follow after that.
  - When a node type supports multiple DW_TAGs, but one is implied by
    its name and is overwhelmingly more common, the `tag:` field is
    terribly uninteresting unless it's different.
      - `MDBasicType` is almost always `DW_TAG_base_type`.
      - `MDTemplateValueParameter` is almost always
        `DW_TAG_template_value_parameter`.
  - Printing `name: ""` doesn't improve CHECK-ability, and there are far
    more nodes than I realized that are commonly nameless.
  - There are a few other fields that similarly aren't very interesting
    when they're empty.

This commit updates the `AsmWriter` as suggested above (and makes
necessary changes in `LLParser` for round-tripping).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230877 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-28 23:21:38 +00:00
9f8d4037a6 AsmParser/Writer: Handle symbolic constants in DI 'flags:'
Parse (and write) symbolic constants in debug info `flags:` fields.
This prevents a readability (and CHECK-ability) regression with the new
debug info hierarchy.

Old (well, current) assembly, with pretty-printing:

    !{!"...\\0016387", ...} ; ... [public] [rvalue reference]

Flags field without this change:

   !MDDerivedType(flags: 16387, ...)

Flags field with this change:

   !MDDerivedType(flags: DIFlagPublic | DIFlagRValueReference, ...)

As discussed in the review thread, this isn't a final state.  Most of
these flags correspond to `DW_AT_` symbolic constants, and we might
eventually want to support arbitrary attributes in some form.  However,
as it stands now, some of the flags correspond to other concepts (like
`FlagStaticMember`); until things are refactored this is the simplest
way to move forward without regressing assembly.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230111 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-21 01:02:18 +00:00
99f12691dd IR: Change MDFile to directly store the filename/directory
In the old (well, current) schema, there are two types of file
references: untagged and tagged (the latter references the former).

    !0 = !{!"filename", !"/directory"}
    !1 = !{!"0x29", !1} ; DW_TAG_file_type [filename] [/directory]

The interface to `DIBuilder` universally takes the tagged version,
described by `DIFile`.  However, most `file:` references actually use
the untagged version directly.

In the new hierarchy, I'm merging this into a single node: `MDFile`.

Originally I'd planned to keep the old schema unchanged until after I
moved the new hierarchy into place.

However, it turns out to be trivial to make `MDFile` match both nodes at
the same time.

  - Anyone referencing !1 does so through `DIFile`, whose implementation
    I need to gut anyway (as I do the rest of the `DIDescriptor`s).
  - Anyone referencing !0 just references an `MDNode`, and expects a
    node with two `MDString` operands.

This commit achieves that, and updates all the testcases for the parts
of the new hierarchy that used the two-node schema (I've replaced the
untagged nodes with `distinct !{}` to make the diff clear (otherwise the
metadata all gets renumbered); it might be worthwhile to come back and
delete those nodes and renumber the world, not sure).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230057 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-20 20:35:17 +00:00
a342d827bd AsmWriter/Bitcode: MDLocalVariable
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229022 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 01:39:44 +00:00