elf: add EF_MIPS_ABI_* e_flags constants #433
Conversation
|
I just added the Edit: I still need to update the testfiles |
|
I think |
|
The existing MIPS test files show |
|
As long as the tests pass for you locally, then this PR would just need to update the submodule too. I don't think there's anything else. |
|
We may want to check that the object/crates/examples/src/readobj/pe.rs Lines 423 to 429 in f18fc4b |
Done and I updated the testfile references. I think the only thing left is updating the submodule, but I assume that has to be after the test binaries are merged. |
|
Thanks! I'm guessing you want a release with this, so I'll try to do one in the near future. |
|
A release would help fix some issues in the |
|
Published 0.28.4. |
In rust-lang#95604 the compiler started generating a temporary symbols.o which is added to the linker invocation. This object file has an `e_flags` which may be invalid for 32-bit MIPS targets. Even though symbols.o doesn't contain code, linking with [lld fails](https://github.com/llvm/llvm-project/blob/main/lld/ELF/Arch/MipsArchTree.cpp#L79) with ``` rust-lld: error: foo-cgu.0.rcgu.o: ABI 'o32' is incompatible with target ABI 'n64' ``` because it omits the ABI bits (EF_MIPS_ABI_O32) so lld assumes it's using the N64 ABI. This breaks linking on nightly for the out-of-tree [psx target](ayrtonm/psx-sdk-rs#9), the builtin mipsel-sony-psp target (cc @overdrivenpotato) and any other 32-bit MIPS target using lld. This PR sets the ABI in `e_flags` to O32 since that's the only ABI for 32-bit MIPS that LLVM supports. It also sets other `e_flags` bits based on the target. I had to bump the object crate version since some of these constants were [added recently](gimli-rs/object#433). I'm not sure if this PR needs a test, but I can confirm that it fixes the linking issue on both targets I mentioned.
Fix e_flags for 32-bit MIPS targets in generated object file In rust-lang#95604 the compiler started generating a temporary symbols.o which is added to the linker invocation. This object file has an `e_flags` which is invalid for 32-bit MIPS targets. Even though symbols.o doesn't contain code, linking these targets with [lld fails](https://github.com/llvm/llvm-project/blob/main/lld/ELF/Arch/MipsArchTree.cpp#L76-L79) with ``` rust-lld: error: foo-cgu.0.rcgu.o: ABI 'o32' is incompatible with target ABI 'n64' ``` because it omits the ABI bits (`EF_MIPS_ABI_O32`) so lld assumes it's using the N64 ABI. This breaks linking on nightly for the out-of-tree [mipsel-sony-psx target](ayrtonm/psx-sdk-rs#9), the builtin mipsel-sony-psp target (cc `@overdrivenpotato)` and probably any other 32-bit MIPS target using lld. This PR sets the ABI in `e_flags` to O32 since that's the only ABI for 32-bit MIPS that LLVM supports. It also sets other `e_flags` bits based on the target to avoid similar issues with the object file arch and PIC. I had to bump the object crate version since some of these constants were [added recently](gimli-rs/object#433). I'm not sure if this PR needs a test, but I can confirm that it fixes the linking issue on both targets I mentioned.
This adds a few constants that are needed to fix some targets that are broken on nightly rustc. Values were taken from the LLVM source.