From a6ca4f529008c8d5aaf81efdace51e5544a4e26b Mon Sep 17 00:00:00 2001
From: bjorn3 <17426603+bjorn3@users.noreply.github.com>
Date: Wed, 5 Nov 2025 09:19:25 +0000
Subject: [PATCH] Move warning reporting from flag_to_backend_features to
 cfg_target_feature

This way warnings are emitted even in a check build.
---
 src/gcc_util.rs | 35 +++++++++++++----------------------
 src/lib.rs      | 38 +++++++++++++++++++++-----------------
 2 files changed, 34 insertions(+), 39 deletions(-)

diff --git a/src/gcc_util.rs b/src/gcc_util.rs
index 702704ddf136..1c9679ead0db 100644
--- a/src/gcc_util.rs
+++ b/src/gcc_util.rs
@@ -11,7 +11,7 @@ fn gcc_features_by_flags(sess: &Session, features: &mut Vec<String>) {
 
 /// The list of GCC features computed from CLI flags (`-Ctarget-cpu`, `-Ctarget-feature`,
 /// `--target` and similar).
-pub(crate) fn global_gcc_features(sess: &Session, diagnostics: bool) -> Vec<String> {
+pub(crate) fn global_gcc_features(sess: &Session) -> Vec<String> {
     // Features that come earlier are overridden by conflicting features later in the string.
     // Typically we'll want more explicit settings to override the implicit ones, so:
     //
@@ -36,27 +36,18 @@ pub(crate) fn global_gcc_features(sess: &Session, diagnostics: bool) -> Vec<Stri
     features.extend(sess.target.features.split(',').filter(|v| !v.is_empty()).map(String::from));
 
     // -Ctarget-features
-    target_features::flag_to_backend_features(
-        sess,
-        diagnostics,
-        |feature| to_gcc_features(sess, feature),
-        |feature, enable| {
-            // We run through `to_gcc_features` when
-            // passing requests down to GCC. This means that all in-language
-            // features also work on the command line instead of having two
-            // different names when the GCC name and the Rust name differ.
-            features.extend(
-                to_gcc_features(sess, feature)
-                    .iter()
-                    .flat_map(|feat| to_gcc_features(sess, feat).into_iter())
-                    .map(
-                        |feature| {
-                            if !enable { format!("-{}", feature) } else { feature.to_string() }
-                        },
-                    ),
-            );
-        },
-    );
+    target_features::flag_to_backend_features(sess, |feature, enable| {
+        // We run through `to_gcc_features` when
+        // passing requests down to GCC. This means that all in-language
+        // features also work on the command line instead of having two
+        // different names when the GCC name and the Rust name differ.
+        features.extend(
+            to_gcc_features(sess, feature)
+                .iter()
+                .flat_map(|feat| to_gcc_features(sess, feat).into_iter())
+                .map(|feature| if !enable { format!("-{}", feature) } else { feature.to_string() }),
+        );
+    });
 
     gcc_features_by_flags(sess, &mut features);
 
diff --git a/src/lib.rs b/src/lib.rs
index 71500ded0203..2777bb5ac142 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -107,7 +107,7 @@ use rustc_target::spec::RelocModel;
 use tempfile::TempDir;
 
 use crate::back::lto::ModuleBuffer;
-use crate::gcc_util::target_cpu;
+use crate::gcc_util::{target_cpu, to_gcc_features};
 
 rustc_fluent_macro::fluent_messages! { "../messages.ftl" }
 
@@ -220,7 +220,7 @@ impl CodegenBackend for GccCodegenBackend {
     }
 
     fn provide(&self, providers: &mut Providers) {
-        providers.global_backend_features = |tcx, ()| gcc_util::global_gcc_features(tcx.sess, true)
+        providers.global_backend_features = |tcx, ()| gcc_util::global_gcc_features(tcx.sess)
     }
 
     fn codegen_crate(&self, tcx: TyCtxt<'_>) -> Box<dyn Any> {
@@ -446,21 +446,25 @@ fn to_gcc_opt_level(optlevel: Option<OptLevel>) -> OptimizationLevel {
 
 /// Returns the features that should be set in `cfg(target_feature)`.
 fn target_config(sess: &Session, target_info: &LockedTargetInfo) -> TargetConfig {
-    let (unstable_target_features, target_features) = cfg_target_feature(sess, |feature| {
-        // TODO: we disable Neon for now since we don't support the LLVM intrinsics for it.
-        if feature == "neon" {
-            return false;
-        }
-        target_info.cpu_supports(feature)
-        // cSpell:disable
-        /*
-          adx, aes, avx, avx2, avx512bf16, avx512bitalg, avx512bw, avx512cd, avx512dq, avx512er, avx512f, avx512fp16, avx512ifma,
-          avx512pf, avx512vbmi, avx512vbmi2, avx512vl, avx512vnni, avx512vp2intersect, avx512vpopcntdq,
-          bmi1, bmi2, cmpxchg16b, ermsb, f16c, fma, fxsr, gfni, lzcnt, movbe, pclmulqdq, popcnt, rdrand, rdseed, rtm,
-          sha, sse, sse2, sse3, sse4.1, sse4.2, sse4a, ssse3, tbm, vaes, vpclmulqdq, xsave, xsavec, xsaveopt, xsaves
-        */
-        // cSpell:enable
-    });
+    let (unstable_target_features, target_features) = cfg_target_feature(
+        sess,
+        |feature| to_gcc_features(sess, feature),
+        |feature| {
+            // TODO: we disable Neon for now since we don't support the LLVM intrinsics for it.
+            if feature == "neon" {
+                return false;
+            }
+            target_info.cpu_supports(feature)
+            // cSpell:disable
+            /*
+              adx, aes, avx, avx2, avx512bf16, avx512bitalg, avx512bw, avx512cd, avx512dq, avx512er, avx512f, avx512fp16, avx512ifma,
+              avx512pf, avx512vbmi, avx512vbmi2, avx512vl, avx512vnni, avx512vp2intersect, avx512vpopcntdq,
+              bmi1, bmi2, cmpxchg16b, ermsb, f16c, fma, fxsr, gfni, lzcnt, movbe, pclmulqdq, popcnt, rdrand, rdseed, rtm,
+              sha, sse, sse2, sse3, sse4.1, sse4.2, sse4a, ssse3, tbm, vaes, vpclmulqdq, xsave, xsavec, xsaveopt, xsaves
+            */
+            // cSpell:enable
+        },
+    );
 
     let has_reliable_f16 = target_info.supports_target_dependent_type(CType::Float16);
     let has_reliable_f128 = target_info.supports_target_dependent_type(CType::Float128);