Auto merge of rust-lang#157007 - Kobzol:reject-invalid-backend, r=jieyouxu

Reject invalid codegen backends on CI

The way we set codegen backends in CI jobs contained several bugs.

1) We didn't check if the specified codegen backend is valid. That can be useful in forks, but not on our CI, there it should be a loud error.
2) The codegen backends were specified with weird quoting that was (I think) producing invalid backends.
3) The specified backends in `RUST_CONFIGURE_ARGS` were being overridden due to `run.sh` setting codegen backends based on the `CODEGEN_BACKENDS` environment variable (see rust-lang#156989).

This PR should fix all of these.

After doing some CI runs on this PR, I realized that setting `CODEGEN_BACKENDS` from within the Dockerfile doesn't work, because we use `docker run --env CODEGEN_BACKENDS`, and that will unset the inner env even if the same env is not actually configured in the environment from where `docker run` is executed (sigh). So instead I decided to pass the env variables from `jobs.yml`. It's not really pretty, but it is a solution that should work with the current structure.

Author: bors

src/bootstrap/src/core/config/toml/rust.rs

@@ -1,6 +1,7 @@
 //! This module defines the `Rust` struct, which represents the `[rust]` table
 //! in the `bootstrap.toml` configuration file.
 
+use build_helper::ci::CiEnv;
 use serde::{Deserialize, Deserializer};
 
 use crate::core::config::toml::TomlConfig;
@@ -422,6 +423,11 @@ pub(crate) fn parse_codegen_backends(
             )
         }
         if !BUILTIN_CODEGEN_BACKENDS.contains(&backend.as_str()) {
+            if CiEnv::is_rust_lang_managed_ci_job() {
+                eprintln!("Unknown codegen backend {backend}");
+                exit!(1);
+            }
+
             println!(
                 "HELP: '{backend}' for '{section}.codegen-backends' might fail. \
                 List of known codegen backends: {BUILTIN_CODEGEN_BACKENDS:?}"

src/ci/docker/host-x86_64/x86_64-gnu-gcc-core-tests/Dockerfile

@@ -1,5 +1,5 @@
-# This Dockerfile builds sysroot crates with the GCC backend and then run libcore tests
-# with it.
+# This Dockerfile builds sysroot crates with the GCC backend and then runs
+# libcore tests with the GCC backend.
 
 FROM ubuntu:22.04
 
@@ -40,8 +40,7 @@ ENV RUST_CONFIGURE_ARGS="--build=x86_64-unknown-linux-gnu \
  --enable-sanitizers \
  --enable-profiler \
  --enable-compiler-docs \
- --set llvm.libzstd=true \
- --set rust.codegen-backends=[\\\"gcc\\\"]"
+ --set llvm.libzstd=true"
 ENV SCRIPT="python3 ../x.py \
   --stage 1 \
   test library/coretests \

src/ci/docker/host-x86_64/x86_64-gnu-gcc/Dockerfile

@@ -1,5 +1,5 @@
-# This Dockerfile builds sysroot with the LLVM backendsthen run tests with the
-# GCC backend.
+# This Dockerfile builds sysroot with the LLVM backend and then runs tests
+# with the GCC backend.
 
 FROM ubuntu:22.04
 
@@ -39,8 +39,7 @@ ENV RUST_CONFIGURE_ARGS="--build=x86_64-unknown-linux-gnu \
  --enable-sanitizers \
  --enable-profiler \
  --enable-compiler-docs \
- --set llvm.libzstd=true \
- --set rust.codegen-backends=[\\\"llvm\\\",\\\"gcc\\\"]"
+ --set llvm.libzstd=true"
 ENV SCRIPT="python3 ../x.py \
   --stage 2 \
   test tests \
@@ -52,5 +51,4 @@ ENV SCRIPT="python3 ../x.py \
   --skip tests/rustdoc-js \
   --skip tests/rustdoc-js-std \
   --skip tests/rustdoc-json \
-  --skip tests/rustdoc-ui \
-  --set rust.codegen-backends=[\\\"llvm\\\",\\\"gcc\\\"]"
+  --skip tests/rustdoc-ui"

src/ci/github-actions/jobs.yml

@@ -144,9 +144,13 @@ pr:
     <<: *job-linux-4c
   - name: x86_64-gnu-gcc
     doc_url: https://rustc-dev-guide.rust-lang.org/tests/codegen-backend-tests/cg_gcc.html
+    env:
+      CODEGEN_BACKENDS: llvm,gcc
     <<: *job-linux-4c
   - name: x86_64-gnu-gcc-core-tests
     doc_url: https://rustc-dev-guide.rust-lang.org/tests/codegen-backend-tests/cg_gcc.html
+    env:
+      CODEGEN_BACKENDS: gcc
     <<: *job-linux-4c
 
 # Jobs that run when you perform a try build (@bors try)
@@ -361,14 +365,6 @@ auto:
     continue_on_error: true
     <<: *job-linux-4c
 
-  - name: x86_64-gnu-gcc
-    doc_url: https://rustc-dev-guide.rust-lang.org/tests/codegen-backend-tests/cg_gcc.html
-    <<: *job-linux-4c
-
-  - name: x86_64-gnu-gcc-core-tests
-    doc_url: https://rustc-dev-guide.rust-lang.org/tests/codegen-backend-tests/cg_gcc.html
-    <<: *job-linux-4c
-
   # This job ensures commits landing on nightly still pass the full
   # test suite on the stable channel. There are some UI tests that
   # depend on the channel being built (for example if they include the

src/ci/run.sh

@@ -58,6 +58,12 @@ if [ "$FORCE_CI_RUSTC" == "" ]; then
     DISABLE_CI_RUSTC_IF_INCOMPATIBLE=1
 fi
 
+if [[ "$RUST_CONFIGURE_ARGS" == *"rust.codegen-backends"* ]]; then
+  echo "error: Please specify codegen backends using the CODEGEN_BACKENDS environment variable, \
+not via RUST_CONFIGURE_ARGS."
+  exit 1
+fi
+
 RUST_CONFIGURE_ARGS="$RUST_CONFIGURE_ARGS --set build.print-step-timings --enable-verbose-tests"
 RUST_CONFIGURE_ARGS="$RUST_CONFIGURE_ARGS --set build.metrics"
 RUST_CONFIGURE_ARGS="$RUST_CONFIGURE_ARGS --enable-verbose-configure"