Move revision-specific args to a custom flag

CHANGELOG.md

@@ -15,6 +15,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Changed
 
+* moved rustc revision-specific arguments (`--cfg=<revision>`...) to a custom flag (`custom_flags::revision_args`)
+
 ## [0.27.0] - 2024-10-07
 
 ### Added

src/config.rs

@@ -1,6 +1,7 @@
 #[cfg(feature = "rustc")]
 use crate::{
-    aux_builds::AuxBuilder, custom_flags::edition::Edition, custom_flags::run::Run,
+    aux_builds::AuxBuilder, custom_flags::edition::Edition,
+    custom_flags::revision_args::RustcRevisionArgs, custom_flags::run::Run,
     custom_flags::rustfix::RustfixMode, custom_flags::Flag, filter::Match,
 };
 use crate::{
@@ -129,6 +130,9 @@ impl Config {
             }
         }
 
+        comment_defaults
+            .base()
+            .add_custom("rustc-revision-args", RustcRevisionArgs);
         comment_defaults
             .base()
             .add_custom("edition", Edition("2021".into()));

src/custom_flags.rs

@@ -11,6 +11,8 @@ use std::{
 #[cfg(feature = "rustc")]
 pub mod edition;
 #[cfg(feature = "rustc")]
+pub mod revision_args;
+#[cfg(feature = "rustc")]
 pub mod run;
 pub mod rustfix;
 

src/custom_flags/revision_args.rs

@@ -0,0 +1,32 @@
+//! Custom flag for setting rustc revision-specific args.
+
+use super::Flag;
+use crate::{build_manager::BuildManager, per_test_config::TestConfig, Errored};
+
+/// Set rustc revision-specific args.
+#[derive(Clone, Debug)]
+pub struct RustcRevisionArgs;
+
+impl Flag for RustcRevisionArgs {
+    fn clone_inner(&self) -> Box<dyn Flag> {
+        Box::new(self.clone())
+    }
+
+    fn must_be_unique(&self) -> bool {
+        true
+    }
+
+    fn apply(
+        &self,
+        cmd: &mut std::process::Command,
+        config: &TestConfig,
+        _build_manager: &BuildManager,
+    ) -> Result<(), Errored> {
+        let revision = config.status.revision();
+        if !revision.is_empty() {
+            cmd.arg(format!("--cfg={revision}"));
+            cmd.arg(format!("-Cextra-filename={revision}"));
+        }
+        Ok(())
+    }
+}

src/per_test_config.rs

@@ -133,10 +133,6 @@ impl TestConfig {
     pub fn build_command(&self, build_manager: &BuildManager) -> Result<Command, Errored> {
         let mut cmd = self.config.program.build(&self.config.out_dir);
         cmd.arg(self.status.path());
-        if !self.status.revision().is_empty() {
-            cmd.arg(format!("--cfg={}", self.status.revision()));
-            cmd.arg(format!("-Cextra-filename={}", self.status.revision()));
-        }
         for r in self.comments() {
             cmd.args(&r.compile_flags);
         }