This has is a nice-to-have for me. Frequently I want to run a specific
test, and end up digging through output to be able to copy-paste the run
line. This uses TIP lines to inject the command into the file when using
AUTOUPDATE.
Note, one of the reasons I want this is because "bazel test
//toolchain/testing:file_test --test_output=all" has been regularly
exceeding bazel's output limit for me (workaround is either opening the
output file or specifying an obscure output limit flag), making it a
little harder for me to get the commands. However, frequently I'm adding
a file and want to iterate on it, so that's really the use case I have
in mind here.
Factor out `SemIR::InstNamer` and also use it when lowering to LLVM IR.
Automatically name all instructions created with our `IRBuilder` based
on the name computed by the `InstNamer`, and likewise name basic blocks
using the label generated by the `InstNamer`.
Move some of the existing naming logic out from lower into `InstNamer`
so that it's also used in SemIR. In particular, we now name call
instructions after their callee, or after the builtin name for calls to
builtins.
Computing and adding these names isn't completely free. This instruction
naming is designed to be optional, so that we can turn it off for builds
where the LLVM IR will only be converted to assembly and won't be seen
by a human, but so far it's enabled unconditionally. We can tune that
later as needed.
Fix a bug where we would perform the computation of the return location
in SemIR after we have already used it in some cases, leading to
assertion failures during lowering. Instead, accumulate a sequence of
instructions to compute the return location in a temporary block, and
overwrite the return slot with those instructions when we perform
initialization.
StubReference is replaced by a more general SpliceBlock node, that takes
a code block and a result value, executes the instructions in the block,
and produces the result. This is used in the uncommon case where more
than one instruction is required to compute the return slot, which can
happen if we need to first emit a temporary and then index into it, or
if we need to perform multiple levels of indexing before we reach an
entity to initialize.
Jon Ross-Perkins
Richard Smith