From 3acb505ee560770c62bad5362f6caf7567d467b9 Mon Sep 17 00:00:00 2001 From: Joshua Nelson Date: Wed, 14 Sep 2022 19:33:00 -0500 Subject: [PATCH] Make the `c` feature for `compiler-builtins` opt-in instead of inferred The build script for `compiler_builtins` doesn't support cross-compilation. I tried fixing it, but the cc crate itself doesn't appear to support cross-compiling to windows either unless you use the -gnu toolchain: ``` error occurred: Failed to find tool. Is `lib.exe` installed? ``` Rather than trying to fix it or special-case the platforms without bugs, make it opt-in instead of automatic. --- config.toml.example | 4 +++ src/bootstrap/compile.rs | 15 ++++++--- src/bootstrap/config.rs | 4 +++ src/bootstrap/dist.rs | 32 +++++++++---------- .../disabled/dist-x86_64-haiku/Dockerfile | 2 ++ .../host-x86_64/dist-various-2/Dockerfile | 2 ++ .../x86_64-gnu-llvm-13-stage1/Dockerfile | 1 + .../host-x86_64/x86_64-gnu-llvm-13/Dockerfile | 1 + src/ci/run.sh | 5 +++ 9 files changed, 44 insertions(+), 22 deletions(-) diff --git a/config.toml.example b/config.toml.example index a967d881b02..ff08dfc553d 100644 --- a/config.toml.example +++ b/config.toml.example @@ -291,6 +291,10 @@ changelog-seen = 2 # on this runtime, such as `-C profile-generate` or `-C instrument-coverage`). #profiler = false +# Use the optimized LLVM C intrinsics for `compiler_builtins`, rather than Rust intrinsics. +# Requires the LLVM submodule to be managed by bootstrap (i.e. not external). +#optimized-compiler-builtins = false + # Indicates whether the native libraries linked into Cargo will be statically # linked or not. #cargo-native-static = false diff --git a/src/bootstrap/compile.rs b/src/bootstrap/compile.rs index c13e83f6c86..58cf3edc317 100644 --- a/src/bootstrap/compile.rs +++ b/src/bootstrap/compile.rs @@ -299,9 +299,7 @@ pub fn std_cargo(builder: &Builder<'_>, target: TargetSelection, stage: u32, car // Determine if we're going to compile in optimized C intrinsics to // the `compiler-builtins` crate. These intrinsics live in LLVM's - // `compiler-rt` repository, but our `src/llvm-project` submodule isn't - // always checked out, so we need to conditionally look for this. (e.g. if - // an external LLVM is used we skip the LLVM submodule checkout). + // `compiler-rt` repository. // // Note that this shouldn't affect the correctness of `compiler-builtins`, // but only its speed. Some intrinsics in C haven't been translated to Rust @@ -312,8 +310,15 @@ pub fn std_cargo(builder: &Builder<'_>, target: TargetSelection, stage: u32, car // If `compiler-rt` is available ensure that the `c` feature of the // `compiler-builtins` crate is enabled and it's configured to learn where // `compiler-rt` is located. - let compiler_builtins_root = builder.src.join("src/llvm-project/compiler-rt"); - let compiler_builtins_c_feature = if compiler_builtins_root.exists() { + let compiler_builtins_c_feature = if builder.config.optimized_compiler_builtins { + if !builder.is_rust_llvm(target) { + panic!( + "need a managed LLVM submodule for optimized intrinsics support; unset `llvm-config` or `optimized-compiler-builtins`" + ); + } + + builder.update_submodule(&Path::new("src").join("llvm-project")); + let compiler_builtins_root = builder.src.join("src/llvm-project/compiler-rt"); // Note that `libprofiler_builtins/build.rs` also computes this so if // you're changing something here please also change that. cargo.env("RUST_COMPILER_RT_ROOT", &compiler_builtins_root); diff --git a/src/bootstrap/config.rs b/src/bootstrap/config.rs index 7c062460c4f..1924ff09d49 100644 --- a/src/bootstrap/config.rs +++ b/src/bootstrap/config.rs @@ -73,6 +73,8 @@ pub struct Config { pub color: Color, pub patch_binaries_for_nix: bool, pub stage0_metadata: Stage0Metadata, + /// Whether to use the `c` feature of the `compiler_builtins` crate. + pub optimized_compiler_builtins: bool, pub on_fail: Option, pub stage: u32, @@ -597,6 +599,7 @@ define_config! { bench_stage: Option = "bench-stage", patch_binaries_for_nix: Option = "patch-binaries-for-nix", metrics: Option = "metrics", + optimized_compiler_builtins: Option = "optimized-compiler-builtins", } } @@ -916,6 +919,7 @@ impl Config { set(&mut config.print_step_timings, build.print_step_timings); set(&mut config.print_step_rusage, build.print_step_rusage); set(&mut config.patch_binaries_for_nix, build.patch_binaries_for_nix); + set(&mut config.optimized_compiler_builtins, build.optimized_compiler_builtins); config.verbose = cmp::max(config.verbose, flags.verbose); diff --git a/src/bootstrap/dist.rs b/src/bootstrap/dist.rs index 1a59b3958f1..b66c08ea4c4 100644 --- a/src/bootstrap/dist.rs +++ b/src/bootstrap/dist.rs @@ -1838,23 +1838,21 @@ fn add_env(builder: &Builder<'_>, cmd: &mut Command, target: TargetSelection) { /// /// Returns whether the files were actually copied. fn maybe_install_llvm(builder: &Builder<'_>, target: TargetSelection, dst_libdir: &Path) -> bool { - if let Some(config) = builder.config.target_config.get(&target) { - if config.llvm_config.is_some() && !builder.config.llvm_from_ci { - // If the LLVM was externally provided, then we don't currently copy - // artifacts into the sysroot. This is not necessarily the right - // choice (in particular, it will require the LLVM dylib to be in - // the linker's load path at runtime), but the common use case for - // external LLVMs is distribution provided LLVMs, and in that case - // they're usually in the standard search path (e.g., /usr/lib) and - // copying them here is going to cause problems as we may end up - // with the wrong files and isn't what distributions want. - // - // This behavior may be revisited in the future though. - // - // If the LLVM is coming from ourselves (just from CI) though, we - // still want to install it, as it otherwise won't be available. - return false; - } + if !builder.is_rust_llvm(target) { + // If the LLVM was externally provided, then we don't currently copy + // artifacts into the sysroot. This is not necessarily the right + // choice (in particular, it will require the LLVM dylib to be in + // the linker's load path at runtime), but the common use case for + // external LLVMs is distribution provided LLVMs, and in that case + // they're usually in the standard search path (e.g., /usr/lib) and + // copying them here is going to cause problems as we may end up + // with the wrong files and isn't what distributions want. + // + // This behavior may be revisited in the future though. + // + // If the LLVM is coming from ourselves (just from CI) though, we + // still want to install it, as it otherwise won't be available. + return false; } // On macOS, rustc (and LLVM tools) link to an unversioned libLLVM.dylib diff --git a/src/ci/docker/host-x86_64/disabled/dist-x86_64-haiku/Dockerfile b/src/ci/docker/host-x86_64/disabled/dist-x86_64-haiku/Dockerfile index 5ddd3f18039..637b5fa22f9 100644 --- a/src/ci/docker/host-x86_64/disabled/dist-x86_64-haiku/Dockerfile +++ b/src/ci/docker/host-x86_64/disabled/dist-x86_64-haiku/Dockerfile @@ -47,4 +47,6 @@ ENV RUST_CONFIGURE_ARGS --disable-jemalloc \ --set=$TARGET.cc=x86_64-unknown-haiku-gcc \ --set=$TARGET.cxx=x86_64-unknown-haiku-g++ \ --set=$TARGET.llvm-config=/bin/llvm-config-haiku +ENV EXTERNAL_LLVM 1 + ENV SCRIPT python3 ../x.py dist --host=$HOST --target=$HOST diff --git a/src/ci/docker/host-x86_64/dist-various-2/Dockerfile b/src/ci/docker/host-x86_64/dist-various-2/Dockerfile index 126c292b38e..8250ec0c311 100644 --- a/src/ci/docker/host-x86_64/dist-various-2/Dockerfile +++ b/src/ci/docker/host-x86_64/dist-various-2/Dockerfile @@ -129,4 +129,6 @@ ENV RUST_CONFIGURE_ARGS --enable-extended --enable-lld --disable-docs \ --set target.wasm32-wasi.wasi-root=/wasm32-wasi \ --musl-root-armv7=/musl-armv7 +ENV EXTERNAL_LLVM 1 + ENV SCRIPT python3 ../x.py dist --host='' --target $TARGETS diff --git a/src/ci/docker/host-x86_64/x86_64-gnu-llvm-13-stage1/Dockerfile b/src/ci/docker/host-x86_64/x86_64-gnu-llvm-13-stage1/Dockerfile index 23f2215c2d9..1289f116fe9 100644 --- a/src/ci/docker/host-x86_64/x86_64-gnu-llvm-13-stage1/Dockerfile +++ b/src/ci/docker/host-x86_64/x86_64-gnu-llvm-13-stage1/Dockerfile @@ -29,6 +29,7 @@ RUN sh /scripts/sccache.sh # We are disabling CI LLVM since this builder is intentionally using a host # LLVM, rather than the typical src/llvm-project LLVM. ENV NO_DOWNLOAD_CI_LLVM 1 +ENV EXTERNAL_LLVM 1 # Using llvm-link-shared due to libffi issues -- see #34486 ENV RUST_CONFIGURE_ARGS \ diff --git a/src/ci/docker/host-x86_64/x86_64-gnu-llvm-13/Dockerfile b/src/ci/docker/host-x86_64/x86_64-gnu-llvm-13/Dockerfile index 8f6831bc54e..4b89a72baa1 100644 --- a/src/ci/docker/host-x86_64/x86_64-gnu-llvm-13/Dockerfile +++ b/src/ci/docker/host-x86_64/x86_64-gnu-llvm-13/Dockerfile @@ -40,6 +40,7 @@ RUN sh /scripts/sccache.sh # We are disabling CI LLVM since this builder is intentionally using a host # LLVM, rather than the typical src/llvm-project LLVM. ENV NO_DOWNLOAD_CI_LLVM 1 +ENV EXTERNAL_LLVM 1 # Using llvm-link-shared due to libffi issues -- see #34486 ENV RUST_CONFIGURE_ARGS \ diff --git a/src/ci/run.sh b/src/ci/run.sh index 9a247fb60a8..9d98ce22498 100755 --- a/src/ci/run.sh +++ b/src/ci/run.sh @@ -69,6 +69,11 @@ RUST_CONFIGURE_ARGS="$RUST_CONFIGURE_ARGS --set rust.codegen-units-std=1" # space required for CI artifacts. RUST_CONFIGURE_ARGS="$RUST_CONFIGURE_ARGS --dist-compression-formats=xz" +# Enable the `c` feature for compiler_builtins, but only when the `compiler-rt` source is available. +if [ "$EXTERNAL_LLVM" = "" ]; then + RUST_CONFIGURE_ARGS="$RUST_CONFIGURE_ARGS --set build.optimized-compiler-builtins" +fi + if [ "$DIST_SRC" = "" ]; then RUST_CONFIGURE_ARGS="$RUST_CONFIGURE_ARGS --disable-dist-src" fi