IR: Add assembly/bitcode support for function metadata attachments

Add serialization support for function metadata attachments (added in
r235783).  The syntax is:

    define @foo() !attach !0 {

Metadata attachments are only allowed on functions with bodies.  Since
they come before the `{`, they're not really part of the body; since
they require a body, they're not really part of the header.  In
`LLParser` I gave them a separate function called from `ParseDefine()`,
`ParseOptionalFunctionMetadata()`.

In bitcode, I'm using the same `METADATA_ATTACHMENT` record used by
instructions.  Instruction metadata attachments are included in a
special "attachment" block at the end of a `Function`.  The attachment
records are laid out like this:

    InstID (KindID MetadataID)+

Note that these records always have an odd number of fields.  The new
code takes advantage of this to recognize function attachments (which
don't need an instruction ID):

    (KindID MetadataID)+

This means we can use the same attachment block already used for
instructions.

This is part of PR23340.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235785 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Duncan P. N. Exon Smith
2015-04-24 22:04:41 +00:00
parent ef477f3580
commit ae3211466a
7 changed files with 76 additions and 9 deletions

View File

@@ -348,6 +348,11 @@ ValueEnumerator::ValueEnumerator(const Module &M,
for (const Argument &A : F.args())
EnumerateType(A.getType());
// Enumerate metadata attached to this function.
F.getAllMetadata(MDs);
for (const auto &I : MDs)
EnumerateMetadata(I.second);
for (const BasicBlock &BB : F)
for (const Instruction &I : BB) {
for (const Use &Op : I.operands()) {