LLVM globals corresponding to miri allocations should be named alloc123.

[eddyb]

That is, if -Zfewer-names is false (usually only because of --emit=llvm-ir), we should use the same name for LLVM globals we generate out of miri allocs as #67133 does in MIR output (allocN).

This way, we can easily see the mapping between MIR and LLVM IR (and it shouldn't be any costlier for regular compilation, which would continue to use unnamed globals).

Relevant code (btw this could probably use extra caching keyed on AllocId?):

rust/src/librustc_codegen_llvm/common.rs

Lines 260 to 267 in be493fe

	Some(GlobalAlloc::Memory(alloc)) => {
	let init = const_alloc_to_llvm(self, alloc);
	if alloc.mutability == Mutability::Mut {
	self.static_addr_of_mut(init, alloc.align, None)
	} else {
	self.static_addr_of(init, alloc.align, None)
	}
	}

cc @rust-lang/wg-mir-opt @bjorn3

This issue has been assigned to @chrissimpkins via this comment.

[oli-obk]

Kinda vague instructions:

1. Replace the None for the static_addr_of_mut and static_addr_of call with a Some by creating the name via ptr.alloc_id.to_string().
2. Run all codegen tests and adjust them as necessary.

[chrissimpkins]

@rustbot claim

[chrissimpkins]

#69155

Mind having a look at the updated checks? They pass on local stage 1 tests of test/codegen, but I can't verify that they are valid expected values.

[chrissimpkins]

merged to master