linker: Move native library search from linker to rustc #138753
Conversation
|
r? @wesleywiser rustbot has assigned @wesleywiser. Use |
rustbot
added
A-run-make
|
This PR modifies cc @jieyouxu Some changes occurred in compiler/rustc_codegen_ssa |
This comment has been minimized.
This comment has been minimized.
For static libraries only, for now. Linker's search by name is still used if rustc's search fails, because linker may search in additional platform-specific directories in addition to directories known to rustc.
In practice this doesn't change anything for current built-in targets
| } else if target != unix && sess.target.is_like_msvc { | ||
| // On Windows MSVC naming scheme `libfoo.a` is used as a fallback from default `foo.lib`. |
There was a problem hiding this comment.
I'm not sure this is correct. To my knowledge, MSVC does not use .a at all for static libs (unless we/the Rust ecosystem have started doing this somewhere). What probably does use .a though would be *-windows-gnu.
This code originated a long time ago, far before MSVC was supported: cb823b0. My hunch is that this probably needs to either be changed to target Windows generally or *-windows-gnu more specifically.
There was a problem hiding this comment.
All built-in targets except windows-msvc already have the libname.a naming scheme in their target specs, so this fallback doesn't apply to them (due to the target != unix condition). So on windows-gnu in particular the fallback is also not necessary.
unless we/the Rust ecosystem have started doing this somewhere
Meson is using the libname.a naming scheme on MSVC and CMake now also supports it due to Meson (#123436, https://mesonbuild.com/FAQ.html#why-does-building-my-project-with-msvc-output-static-libraries-called-libfooa, https://gitlab.kitware.com/cmake/cmake/-/issues/23975).
There was a problem hiding this comment.
Ok, can you mention that Meson and CMake do this in the comment?
|
☔ The latest upstream changes (presumably #138956) made this pull request unmergeable. Please resolve the merge conflicts. |
For static libraries only, for now.
Linker's search by name is still used if rustc's search fails, because linker may search in additional platform-specific directories in addition to directories known to rustc.
So we are basically doing something like #123436 for all targets.
This way we provide best effort support for
+verbatimmodifier even on targets with linkers not supporting it natively.If this is supported for dynamic libraries as well (which is nontrivial), this may also allow us to not pass
-Loptions to the linker at all, although it may cause some breakage from libraries passed to linker directly, without rustc knowing about it.TODO: Some more tests for
+verbatimand library naming fallback on Windows, if they are missing.