c55c26cb36
Add default search path to `Target::search()` The function `Target::search()` accepts a target triple and returns a `Target` struct defining the requested target. There is a `// FIXME 16351: add a sane default search path?` comment that indicates it is desirable to include some sort of default. This was raised in https://github.com/rust-lang/rust/issues/16351 which was closed without any resolution. https://github.com/rust-lang/rust/pull/31117 was proposed, however that has platform-specific logic that is unsuitable for systems without `/etc/`. This patch implements the suggestion raised in https://github.com/rust-lang/rust/issues/16351#issuecomment-180878193 where a `target.json` file may be placed in `$(rustc --print sysroot)/lib/rustlib/<target-triple>/target.json`. This allows shipping a toolchain distribution as a single file that gets extracted to the sysroot.
rustc_target contains some very low-level details that are
specific to different compilation targets and so forth.
For more information about how rustc works, see the rustc dev guide.