tree fe497e08e2a0843f20d7e014154ae5c2a443e7f5
parent 6bf6d50a6ff7685b4aa09172d9d09f03f250da9d
parent a6f4ae864eb9a99117f7475325bf9ffb2c8e8b90
author bors <bors@rust-lang.org> 1534727578 +0000
committer bors <bors@rust-lang.org> 1534727578 +0000

Auto merge of #52101 - japaric:linker-flavor, r=alexcrichton

try to infer linker flavor from linker name and vice versa

This is a second take on PR #50359 that implements the logic proposed in https://github.com/rust-lang/rust/pull/50359#pullrequestreview-116663121

With this change it would become possible to link `thumb*` binaries using GNU's LD on stable as `-C linker=arm-none-eabi-ld` would be enough to change both the linker and the linker flavor from their default values of `arm-none-eabi-gcc` and `gcc`.

To link `thumb*` binaries using rustc's LLD on stable `-Z linker-flavor` would need to be stabilized as `-C linker=rust-lld -Z linker-flavor=ld.lld` are both required to change the linker and the linker flavor, but this PR doesn't propose that. We would probably need some sort of stability guarantee around `rust-lld`'s name and availability to make linking with rustc's LLD truly stable.

With this change it would also be possible to link `thumb*` binaries using a system installed LLD on stable using the `-C linker=ld.lld` flag (provided that `ld.lld` is a symlink to the system installed LLD).

r? @alexcrichton