Auto merge of #117608 - matthiaskrgr:rollup-g9fagmv, r=matthiaskrgr

Rollup of 4 pull requests

Successful merges:

 - #116017 (Don't pass `-stdlib=libc++` when building C files on macOS)
 - #117524 (bootstrap/setup: create hooks directory if non-existing)
 - #117588 (Remove unused LoadResult::DecodeIncrCache variant)
 - #117596 (Add diagnostic items for a few of core's builtin macros)

r? `@ghost`
`@rustbot` modify labels: rollup

compiler/rustc_incremental/messages.ftl

@@ -30,8 +30,6 @@ incremental_create_lock =
     incremental compilation: could not create session directory lock file: {$lock_err}
 incremental_create_new = failed to create {$name} at `{$path}`: {$err}
 
-incremental_decode_incr_cache = could not decode incremental cache: {$err}
-
 incremental_delete_full = error deleting incremental compilation session directory `{$path}`: {$err}
 
 incremental_delete_incompatible =

compiler/rustc_incremental/src/errors.rs

@@ -270,12 +270,6 @@ pub struct LoadDepGraph {
     pub err: std::io::Error,
 }
 
-#[derive(Diagnostic)]
-#[diag(incremental_decode_incr_cache)]
-pub struct DecodeIncrCache {
-    pub err: String,
-}
-
 #[derive(Diagnostic)]
 #[diag(incremental_write_dep_graph)]
 pub struct WriteDepGraph<'a> {

compiler/rustc_incremental/src/persist/load.rs

@@ -30,8 +30,6 @@ pub enum LoadResult<T> {
     DataOutOfDate,
     /// Loading the dep graph failed.
     LoadDepGraph(PathBuf, std::io::Error),
-    /// Decoding loaded incremental cache failed.
-    DecodeIncrCache(Box<dyn std::any::Any + Send>),
 }
 
 impl<T: Default> LoadResult<T> {
@@ -44,9 +42,7 @@ impl<T: Default> LoadResult<T> {
             }
             (
                 Some(IncrementalStateAssertion::Loaded),
-                LoadResult::LoadDepGraph(..)
-                | LoadResult::DecodeIncrCache(..)
-                | LoadResult::DataOutOfDate,
+                LoadResult::LoadDepGraph(..) | LoadResult::DataOutOfDate,
             ) => {
                 sess.emit_fatal(errors::AssertLoaded);
             }
@@ -58,10 +54,6 @@ impl<T: Default> LoadResult<T> {
                 sess.emit_warning(errors::LoadDepGraph { path, err });
                 Default::default()
             }
-            LoadResult::DecodeIncrCache(err) => {
-                sess.emit_warning(errors::DecodeIncrCache { err: format!("{err:?}") });
-                Default::default()
-            }
             LoadResult::DataOutOfDate => {
                 if let Err(err) = delete_all_session_dir_contents(sess) {
                     sess.emit_err(errors::DeleteIncompatible { path: dep_graph_path(sess), err });
@@ -150,7 +142,6 @@ fn load_dep_graph(sess: &Session) -> LoadResult<(SerializedDepGraph, WorkProduct
     match load_data(&path, sess) {
         LoadResult::DataOutOfDate => LoadResult::DataOutOfDate,
         LoadResult::LoadDepGraph(path, err) => LoadResult::LoadDepGraph(path, err),
-        LoadResult::DecodeIncrCache(err) => LoadResult::DecodeIncrCache(err),
         LoadResult::Ok { data: (bytes, start_pos) } => {
             let mut decoder = MemDecoder::new(&bytes, start_pos);
             let prev_commandline_args_hash = u64::decode(&mut decoder);

library/core/src/macros/mod.rs

@@ -1044,6 +1044,7 @@ pub(crate) mod builtin {
     #[stable(feature = "rust1", since = "1.0.0")]
     #[rustc_builtin_macro]
     #[macro_export]
+    #[rustc_diagnostic_item = "env_macro"] // useful for external lints
     macro_rules! env {
         ($name:expr $(,)?) => {{ /* compiler built-in */ }};
         ($name:expr, $error_msg:expr $(,)?) => {{ /* compiler built-in */ }};
@@ -1074,6 +1075,7 @@ pub(crate) mod builtin {
     #[stable(feature = "rust1", since = "1.0.0")]
     #[rustc_builtin_macro]
     #[macro_export]
+    #[rustc_diagnostic_item = "option_env_macro"] // useful for external lints
     macro_rules! option_env {
         ($name:expr $(,)?) => {{ /* compiler built-in */ }};
     }
@@ -1479,6 +1481,7 @@ pub(crate) mod builtin {
     #[stable(feature = "rust1", since = "1.0.0")]
     #[rustc_builtin_macro]
     #[macro_export]
+    #[rustc_diagnostic_item = "include_macro"] // useful for external lints
     macro_rules! include {
         ($file:expr $(,)?) => {{ /* compiler built-in */ }};
     }

src/bootstrap/src/core/build_steps/setup.rs

@@ -469,7 +469,8 @@ fn install_git_hook_maybe(config: &Config) -> io::Result<()> {
         assert!(output.status.success(), "failed to run `git`");
         PathBuf::from(t!(String::from_utf8(output.stdout)).trim())
     }));
-    let dst = git.join("hooks").join("pre-push");
+    let hooks_dir = git.join("hooks");
+    let dst = hooks_dir.join("pre-push");
     if dst.exists() {
         // The git hook has already been set up, or the user already has a custom hook.
         return Ok(());
@@ -486,6 +487,10 @@ undesirable, simply delete the `pre-push` file from .git/hooks."
         println!("Ok, skipping installation!");
         return Ok(());
     }
+    if !hooks_dir.exists() {
+        // We need to (try to) create the hooks directory first.
+        let _ = fs::create_dir(hooks_dir);
+    }
     let src = config.src.join("src").join("etc").join("pre-push.sh");
     match fs::hard_link(src, &dst) {
         Err(e) => {

src/bootstrap/src/lib.rs

@@ -1197,11 +1197,10 @@ impl Build {
             .filter(|s| !s.starts_with("-O") && !s.starts_with("/O"))
             .collect::<Vec<String>>();
 
-        // If we're compiling on macOS then we add a few unconditional flags
-        // indicating that we want libc++ (more filled out than libstdc++) and
-        // we want to compile for 10.7. This way we can ensure that
+        // If we're compiling C++ on macOS then we add a flag indicating that
+        // we want libc++ (more filled out than libstdc++), ensuring that
         // LLVM/etc are all properly compiled.
-        if target.contains("apple-darwin") {
+        if matches!(c, CLang::Cxx) && target.contains("apple-darwin") {
             base.push("-stdlib=libc++".into());
         }