Respect RUSTC_WRAPPER in rustc version detection

.cirrus.yml

@@ -9,6 +9,7 @@ env:
   RUSTDOCFLAGS: -D warnings
   RUSTFLAGS: -D warnings
   RUSTUP_MAX_RETRIES: '10'
+  PORTABLE_ATOMIC_DENY_WARNINGS: '1'
 
 aarch64_linux_test_task:
   name: test ($TARGET)

.github/workflows/ci.yml

@@ -23,6 +23,7 @@ env:
   RUSTDOCFLAGS: -D warnings
   RUSTFLAGS: -D warnings
   RUSTUP_MAX_RETRIES: 10
+  PORTABLE_ATOMIC_DENY_WARNINGS: 1
   # NB: sync with:
   # - docs.rs metadata in Cargo.toml
   # - test_features list in tools/build.sh and tools/test.sh.
@@ -380,7 +381,7 @@ jobs:
       - uses: taiki-e/checkout-action@v1
       - uses: taiki-e/cross-platform-actions-action@neoverse-v1
         with:
-          environment_variables: CARGO_INCREMENTAL CARGO_NET_RETRY CARGO_TERM_COLOR RUST_BACKTRACE RUST_TEST_THREADS RUSTDOCFLAGS RUSTFLAGS RUSTUP_MAX_RETRIES TEST_FEATURES
+          environment_variables: CARGO_INCREMENTAL CARGO_NET_RETRY CARGO_TERM_COLOR RUST_BACKTRACE RUST_TEST_THREADS RUSTDOCFLAGS RUSTFLAGS RUSTUP_MAX_RETRIES PORTABLE_ATOMIC_DENY_WARNINGS TEST_FEATURES
           operating_system: ${{ matrix.os }}
           # We don't test x86_64 here because there is no OS-specific code on x86_64.
           architecture: aarch64

build.rs

@@ -36,6 +36,9 @@ fn main() {
     let version = match rustc_version() {
         Some(version) => version,
         None => {
+            if env::var_os("PORTABLE_ATOMIC_DENY_WARNINGS").unwrap_or_default() == "1" {
+                panic!("unable to determine rustc version")
+            }
             println!(
                 "cargo:warning={}: unable to determine rustc version; assuming latest stable rustc (1.{})",
                 env!("CARGO_PKG_NAME"),
@@ -261,6 +264,9 @@ fn main() {
                 "v4t" | "v5te" => {}
                 _ => {
                     known = false;
+                    if env::var_os("PORTABLE_ATOMIC_DENY_WARNINGS").unwrap_or_default() == "1" {
+                        panic!("unrecognized arm subarch: {}", target)
+                    }
                     println!(
                         "cargo:warning={}: unrecognized arm subarch: {}",
                         env!("CARGO_PKG_NAME"),

portable-atomic-util/build.rs

@@ -17,6 +17,9 @@ fn main() {
     let version = match rustc_version() {
         Some(version) => version,
         None => {
+            if env::var_os("PORTABLE_ATOMIC_DENY_WARNINGS").unwrap_or_default() == "1" {
+                panic!("unable to determine rustc version")
+            }
             println!(
                 "cargo:warning={}: unable to determine rustc version; assuming latest stable rustc (1.{})",
                 env!("CARGO_PKG_NAME"),

tools/build.sh

@@ -247,6 +247,7 @@ if [[ "${rustc_version}" == *"nightly"* ]] || [[ "${rustc_version}" == *"dev"* ]
     fi
 fi
 export CARGO_TARGET_DIR="${target_dir}"
+export PORTABLE_ATOMIC_DENY_WARNINGS=1
 
 has_asm=''
 # asm! requires 1.59

tools/fuchsia-test.sh

@@ -57,6 +57,7 @@ case "${1:-}" in
 esac
 target="$1-unknown-fuchsia"
 shift
+export PORTABLE_ATOMIC_DENY_WARNINGS=1
 
 cargo_options=()
 rest_cargo_options=(--test-threads=1)

tools/no-std.sh

@@ -99,6 +99,7 @@ if [[ "${rustc_version}" == *"nightly"* ]] || [[ "${rustc_version}" == *"dev"* ]
     fi
 fi
 export QEMU_AUDIO_DRV=none
+export PORTABLE_ATOMIC_DENY_WARNINGS=1
 
 run() {
     local target="$1"

tools/test.sh

@@ -143,6 +143,7 @@ if [[ "${rustc_version}" == *"nightly"* ]] || [[ "${rustc_version}" == *"dev"* ]
     fi
 fi
 export RUST_TEST_THREADS=1
+export PORTABLE_ATOMIC_DENY_WARNINGS=1
 if [[ -n "${CI:-}" ]]; then
     if type -P ts &>/dev/null; then
         TS=ts

version.rs

@@ -1,11 +1,23 @@
 // SPDX-License-Identifier: Apache-2.0 OR MIT
 
-use std::{env, process::Command, str};
+use std::{env, iter, process::Command, str};
 
 pub(crate) fn rustc_version() -> Option<Version> {
     let rustc = env::var_os("RUSTC")?;
+    let rustc_wrapper = if env::var_os("CARGO_ENCODED_RUSTFLAGS").is_some() {
+        env::var_os("RUSTC_WRAPPER").filter(|v| !v.is_empty())
+    } else {
+        // Cargo sets environment variables for wrappers correctly only since https://github.com/rust-lang/cargo/pull/9601.
+        None
+    };
+    // Do not apply RUSTC_WORKSPACE_WRAPPER: https://github.com/cuviper/autocfg/issues/58#issuecomment-2067625980
+    let mut rustc = rustc_wrapper.into_iter().chain(iter::once(rustc));
+    let mut cmd = Command::new(rustc.next().unwrap());
+    cmd.args(rustc);
     // Use verbose version output because the packagers add extra strings to the normal version output.
-    let output = Command::new(rustc).args(&["--version", "--verbose"]).output().ok()?;
+    // Do not use long flags (--version --verbose) because clippy-deriver doesn't handle them properly.
+    // -vV is also matched with that cargo internally uses: https://github.com/rust-lang/cargo/blob/14b46ecc62aa671d7477beba237ad9c6a209cf5d/src/cargo/util/rustc.rs#L65
+    let output = cmd.arg("-vV").output().ok()?;
     let verbose_version = str::from_utf8(&output.stdout).ok()?;
     Version::parse(verbose_version)
 }