Clean up JIT<->EE relocations #121920
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Clean up JIT<->EE relocations #121920
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Introduce a `CorInfoReloc` enum and use it exclusively to communicate relocation types between the EE and JIT. Translate it in crossgen2/ILC to the file-format relocation type when necessary.
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Tagging subscribers to this area: @JulieLeeMSFT, @jakobbotsch |
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LGTM |
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@jakobbotsch, I added a smoke test in #121895 to see whether or not it works on community platforms. I tried merging this PR branch and commenting out without your PR, the error/callstack is same as: #121878 (comment). |
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That looks like #121871. It needs a separate change. |
jkotas
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Nov 24, 2025
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Nov 24, 2025
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PTAL @dotnet/jit-contrib @jkotas |
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| return (RelocType)fRelocType; | ||
| } | ||
| } | ||
| // Translates relocation type constants used by JIT to RelocType enumeration |
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Would it make sense to use the CorInfoReloc enumeration inside the ObjectWriter too?
I see the ObjectWriter (the reloc handling in particular) as tightly coupled with the JIT. I am not sure whether we need two nearly identical enums and mapping between them.
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Maybe? I do count a significant number of relocation types that the object writer has that the JIT never uses for its code and that we would not want to care about outside ObjectWriter (in the VM or superpmi particularly).
I suppose we could define those in the managed copy of CorInfoReloc specifically, next to the existing fake relocations that RelocType defines.
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IMAGE_REL_BASED_... constants make it look like that these constants came from Windows SDK, but that's not actually true except ~3 of them. It is a left-over from fragile NGen that a lot of unrelated stuff got added to over time.
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I do count a significant number of relocation types that the object writer has that the JIT never uses
I see SYMBOL_SIZE, FILE_ABSOLUTE, FILE_CHECKSUM_CALLBACK. Anything else?
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Although seems like some of them can be deleted. These are the ones that the JIT does not use:
IMAGE_REL_BASED_ABSOLUTE
IMAGE_REL_BASED_ADDR32NB
IMAGE_REL_BASED_RELPTR32
IMAGE_REL_SECTION
IMAGE_REL_BASED_ARM64_PAGEOFFSET_12L
IMAGE_REL_TPOFF (looks unused)
IMAGE_REL_AARCH64_TLSLE_ADD_TPREL_HI12 (looks unused)
IMAGE_REL_AARCH64_TLSLE_ADD_TPREL_LO12_NC (looks unused)
IMAGE_REL_ARM_PREL31
IMAGE_REL_ARM_JUMP24
IMAGE_REL_SYMBOL_SIZE
IMAGE_REL_FILE_ABSOLUTE
IMAGE_REL_FILE_CHECKSUM_CALLBACK
For example, we could define these starting at 0x1000 in the managed view of the enum.
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LGTM. The additional cleanup can be done in separate PR
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Introduce a
CorInfoRelocenum and use it exclusively to communicate relocation types between the EE and JIT. Translate it in crossgen2/ILC to the file-format relocation type when necessary.Fix #121878