compiletest: Fix the edition of minicore to the latest stable one

src/tools/compiletest/src/directives.rs

@@ -87,10 +87,8 @@ pub(crate) struct TestProps {
     // Regexes that should be expected, in order, on standard out
     pub(crate) regex_error_patterns: Vec<String>,
     /// Edition selected by an `//@ edition` directive, if any.
-    ///
-    /// Automatically added to `compile_flags` during directive processing.
     pub(crate) edition: Option<Edition>,
-    // Extra flags to pass to the compiler
+    // Extra flags to pass to the compiler.
     pub(crate) compile_flags: Vec<String>,
     // Extra flags to pass when the compiled code is run (such as --bench)
     pub(crate) run_flags: Vec<String>,
@@ -405,11 +403,6 @@ impl TestProps {
                 }
             }
         }
-
-        let edition = self.edition.or(config.edition).unwrap_or(Edition::Year(2015));
-        // The edition is added at the start, since flags from //@compile-flags must be passed
-        // to rustc last.
-        self.compile_flags.insert(0, format!("--edition={edition}"));
     }
 
     fn update_pass_fail_mode(&mut self, ln: &DirectiveLine<'_>, config: &Config) {

src/tools/compiletest/src/edition.rs

@@ -10,6 +10,15 @@ pub(crate) enum Edition {
     Future,
 }
 
+impl Edition {
+    pub(crate) const RUSTC_DEFAULT: Self = Self::Year(2015);
+    pub(crate) const LATEST_STABLE: Self = Self::Year(2024);
+
+    pub(crate) fn to_flag(self) -> String {
+        format!("--edition={self}")
+    }
+}
+
 impl std::fmt::Display for Edition {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self {

src/tools/compiletest/src/runtest.rs

@@ -19,6 +19,7 @@ use crate::common::{
     UI_WINDOWS_SVG, expected_output_path, incremental_dir, output_base_dir, output_base_name,
 };
 use crate::directives::{AuxCrate, TestProps};
+use crate::edition::Edition;
 use crate::errors::{Error, ErrorKind, load_errors};
 use crate::executor::TestVariant;
 use crate::output_capture::ConsoleOut;
@@ -224,6 +225,14 @@ struct TestCx<'test> {
     variant: &'test TestVariant,
 }
 
+impl TestCx<'_> {
+    fn edition(self) -> Edition {
+        // We're always explicitly defaulting to rustc's default to suppress the
+        // warning that rustc emits when no edition gets specified.
+        self.props.edition.or(self.config.edition).unwrap_or(Edition::RUSTC_DEFAULT)
+    }
+}
+
 enum ReadFrom {
     Path,
     Stdin(String),
@@ -456,6 +465,7 @@ impl<'test> TestCx<'test> {
             .arg(&aux_dir)
             .arg("-A")
             .arg("internal_features")
+            .arg(self.edition().to_flag())
             .args(&self.props.compile_flags)
             .envs(self.props.rustc_env.clone());
         self.maybe_add_external_args(&mut rustc, &self.config.target_rustcflags);
@@ -570,6 +580,7 @@ impl<'test> TestCx<'test> {
             .arg("internal_features");
         self.set_revision_flags(&mut rustc);
         self.maybe_add_external_args(&mut rustc, &self.config.target_rustcflags);
+        rustc.arg(self.edition().to_flag());
         rustc.args(&self.props.compile_flags);
 
         self.compose_and_run_compiler(rustc, Some(src))
@@ -982,6 +993,7 @@ impl<'test> TestCx<'test> {
             emit,
             allow_unused,
             LinkToAux::Yes,
+            self.edition(),
             passes,
         );
 
@@ -1065,6 +1077,7 @@ impl<'test> TestCx<'test> {
             // FIXME(#160895): While the new solver is enabled by default on nightly,
             // we don't want to use it in our tests for now.
             .arg("-Znext-solver=coherence")
+            .arg(self.edition().to_flag())
             .args(&self.props.compile_flags)
             .args(&self.props.doc_flags);
 
@@ -1105,6 +1118,7 @@ impl<'test> TestCx<'test> {
             rustdoc_merge
                 .arg("-o")
                 .arg(out_dir.as_ref())
+                .arg(self.edition().to_flag())
                 .args(&self.props.compile_flags)
                 .args(&self.props.doc_flags)
                 .arg("--read-doc-meta-dir")
@@ -1383,13 +1397,17 @@ impl<'test> TestCx<'test> {
     /// directory.
     fn build_minicore(&self) -> Utf8PathBuf {
         let output_file_path = self.output_base_dir().join("libminicore.rlib");
+
+        // We want to inherit *all* `TestProps` from the test that added minicore *except*
+        // for the edition which we want to keep fixed to the latest stable one.
         let mut rustc = self.make_compile_args(
             CompilerKind::Rustc,
             &self.config.minicore_path,
             TargetLocation::ThisFile(output_file_path.clone()),
             Emit::None,
             AllowUnused::Yes,
             LinkToAux::No,
+            Edition::LATEST_STABLE,
             vec![],
         );
 
@@ -1471,6 +1489,7 @@ impl<'test> TestCx<'test> {
             Emit::None,
             AllowUnused::No,
             LinkToAux::No,
+            aux_cx.edition(),
             Vec::new(),
         );
         aux_cx.build_all_auxiliary(&aux_dir, &mut aux_rustc);
@@ -1657,6 +1676,7 @@ impl<'test> TestCx<'test> {
         emit: Emit,
         allow_unused: AllowUnused,
         link_to_aux: LinkToAux,
+        edition: Edition,
         passes: Vec<String>, // Vec of passes under mir-opt test to be dumped
     ) -> Command {
         // FIXME(Zalathar): We should have a cleaner distinction between
@@ -2041,6 +2061,7 @@ impl<'test> TestCx<'test> {
             compiler.arg("-Cforce-unwind-tables=yes");
         }
 
+        compiler.arg(edition.to_flag());
         compiler.args(&self.props.compile_flags);
 
         compiler
@@ -2267,6 +2288,7 @@ impl<'test> TestCx<'test> {
             Emit::LlvmIr,
             AllowUnused::No,
             LinkToAux::Yes,
+            self.edition(),
             Vec::new(),
         );
 

src/tools/compiletest/src/runtest/assembly.rs

@@ -42,6 +42,7 @@ impl TestCx<'_> {
             emit,
             AllowUnused::No,
             LinkToAux::Yes,
+            self.edition(),
             Vec::new(),
         );
 

src/tools/compiletest/src/runtest/ui.rs

@@ -260,6 +260,7 @@ impl TestCx<'_> {
                 emit_metadata,
                 AllowUnused::No,
                 LinkToAux::Yes,
+                self.edition(),
                 Vec::new(),
             );
 

src/tools/compiletest/src/rustdoc_gui_test.rs

@@ -33,10 +33,8 @@ impl RustdocGuiTestProps {
 
         let props = TestProps::from_file(test_file_path, None, &config);
 
-        let TestProps { mut compile_flags, run_flags, .. } = props;
-        // We don't want to pass `--edition=2015` in, which is being set by default by
-        // `TestProps::from_file`.
-        compile_flags.remove(0);
+        // FIXME: Why do we need to ignore the edition?
+        let TestProps { edition: _, compile_flags, run_flags, .. } = props;
         Self { compile_flags, run_flags }
     }
 }