f7669ba3d9
Port COFF's https://reviews.llvm.org/D78221 and https://reviews.llvm.org/D137217 to ELF. For the in-process ThinLTO link, `ld.lld --save-temps a.o d/b.o -o out` will create ELF relocatable files `out.lto.a.o`/`d/out.lto.b.o` instead of `out1.lto.o`/`out2.lto.o`. Deriving the LTO-generated relocatable file name from bitcode file names helps debugging. The relocatable file name from the first regular LTO partition does not change: `out.lto.o`. The second, if present due to `--lto-partition=`, changes from `out1.lto.o` to `lto.1.o`. For an archive member, e.g. `d/a.a(coll.o at 8)`, the relocatable file is `d/out.lto.a.a(coll.o at 8).o`. `--lto-emit-asm` file names are changed similarly. `--lto-emit-asm -o out` now creates `out.lto.s` instead of `out`, therefore the `--lto-emit-asm -o -` idiom no longer works. However, I think this new behavior (which matches COFF) is better since keeping or removing `--lto-emit-asm` will dump different files, instead of overwriting the `-o` output file from an executable/shared object to an assembly file. Reviewers: rnk, igorkudrin, xur-llvm, teresajohnson, ZequanWu Reviewed By: teresajohnson Pull Request: https://github.com/llvm/llvm-project/pull/78835
See docs/NewLLD.rst