rust/library/std
bors 54508a26eb Auto merge of #78924 - bjorn3:less_sysroot_build_scripts, r=Mark-Simulacrum
Make the libstd build script smaller

Of all sysroot crates currently only compiler_builtins, miniz_oxide and std require a build script. compiler_builtins uses to conditionally enable certain features and possibly compile a C version ([source](63ccaf11f0/build.rs)), miniz_oxide only uses it to detect if liballoc is supported as the MSRV is 1.34.0 instead of the 1.36.0 which stabilized liballoc ([source](28514ec09f/miniz_oxide/build.rs)). std now only uses it to enable `freebsd12` when the `RUST_STD_FREEBSD_12_ABI` env var is set, to determine if `restricted-std` should be set, to set the `STD_ENV_ARCH` env var identical to `CARGO_CFG_TARGET_ARCH`, and to unconditionally enable `backtrace_in_libstd`.

If all build scripts were to be removed, it would be possible for rustc to completely compile it's own sysroot. It currently requires a rustc version that already has an available libstd to compile the build scripts. If rustc can completely compile it's own sysroot, rustbuild could be simplified to not forcefully use the bootstrap compiler for build scripts.

`@rustbot` modify labels: +T-compiler +libs-impl
2020-11-17 06:37:59 +00:00
..
benches mv std libs to library/ 2020-07-27 19:51:13 -05:00
src Auto merge of #78924 - bjorn3:less_sysroot_build_scripts, r=Mark-Simulacrum 2020-11-17 06:37:59 +00:00
tests mv std libs to library/ 2020-07-27 19:51:13 -05:00
build.rs Make the libstd build script smaller 2020-11-15 16:17:21 +01:00
Cargo.toml add options to use optimized and mangled compiler builtins 2020-11-15 08:23:31 +01:00