n Rust, an enum that carries data in the variants is, essentially, a
discriminated union. Furthermore, the Rust compiler will perform
space optimizations on such enums in some situations. Previously,
DWARF for these constructs was emitted using a hack (a magic field
name); but this approach stopped working when more space optimizations
were added in https://github.com/rust-lang/rust/pull/45225.
This patch changes LLVM to allow discriminated unions to be
represented in DWARF. It adds createDiscriminatedUnionType and
createDiscriminatedMemberType to DIBuilder and then arranges for this
to be emitted using DWARF's DW_TAG_variant_part and DW_TAG_variant.
Note that DWARF requires that a discriminated union be represented as
a structure with a variant part. However, as Rust only needs to emit
pure discriminated unions, this is what I chose to expose on
DIBuilder.
Patch by Tom Tromey!
Differential Revision: https://reviews.llvm.org/D42082
llvm-svn: 324426
Introduced DIMacro and DIMacroFile debug info metadata in the LLVM IR to support macros.
Differential Revision: http://reviews.llvm.org/D14687
llvm-svn: 255245
Finish off PR23080 by renaming the debug info IR constructs from `MD*`
to `DI*`. The last of the `DIDescriptor` classes were deleted in
r235356, and the last of the related typedefs removed in r235413, so
this has all baked for about a week.
Note: If you have out-of-tree code (like a frontend), I recommend that
you get everything compiling and tests passing with the *previous*
commit before updating to this one. It'll be easier to keep track of
what code is using the `DIDescriptor` hierarchy and what you've already
updated, and I think you're extremely unlikely to insert bugs. YMMV of
course.
Back to *this* commit: I did this using the rename-md-di-nodes.sh
upgrade script I've attached to PR23080 (both code and testcases) and
filtered through clang-format-diff.py. I edited the tests for
test/Assembler/invalid-generic-debug-node-*.ll by hand since the columns
were off-by-three. It should work on your out-of-tree testcases (and
code, if you've followed the advice in the previous paragraph).
Some of the tests are in badly named files now (e.g.,
test/Assembler/invalid-mdcompositetype-missing-tag.ll should be
'dicompositetype'); I'll come back and move the files in a follow-up
commit.
llvm-svn: 236120
Add missing checks for `templateParams:` in `MDCompositeType`. Pull the
current check for `MDSubprogram` to reduce duplicated code and fix it up
to print a good message when the immediate operand isn't an `MDTuple`
(as a drive-by, make the same fix to `variables:` in `MDSubprogram`).
llvm-svn: 234177
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).
llvm-svn: 230877
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.
llvm-svn: 230111
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).
llvm-svn: 230057
Put the name before the value in assembly for `MDEnum`. While working
on the testcase upgrade script for the new hierarchy, I noticed that it
"looks nicer" to have the name first, since it lines the names up in the
(somewhat typical) case that they have a common prefix.
llvm-svn: 229747
Adrian Prantl