Auto merge of #125989 - GuillaumeGomez:rollup-xu69i13, r=GuillaumeGomez

Rollup of 11 pull requests

Successful merges:

 - #106186 (Add function `core::iter::chain`)
 - #125596 (Convert `proc_macro_back_compat` lint to an unconditional error.)
 - #125696 (Explain differences between `{Once,Lazy}{Cell,Lock}` types)
 - #125917 (Create `run-make` `env_var` and `env_var_os` helpers)
 - #125927 (Ignore `vec_deque_alloc_error::test_shrink_to_unwind` test on non-unwind targets)
 - #125930 (feat(opt-dist): new flag `--benchmark-cargo-config`)
 - #125932 (Fix typo in the docs of `HashMap::raw_entry_mut`)
 - #125933 (Update books)
 - #125944 (Update fuchsia maintainers)
 - #125946 (Include trailing commas in wrapped function declarations [RustDoc])
 - #125973 (Remove `tests/run-make-fulldeps/pretty-expanded`)

Failed merges:

 - #125815 (`rustc_parse` top-level cleanups)

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

Author: bors

compiler/rustc_expand/messages.ftl

@@ -124,6 +124,9 @@ expand_not_a_meta_item =
 expand_only_one_word =
     must only be one word
 
+expand_proc_macro_back_compat = using an old version of `{$crate_name}`
+    .note = older versions of the `{$crate_name}` crate no longer compile; please update to `{$crate_name}` v{$fixed_version}, or switch to one of the `{$crate_name}` alternatives
+
 expand_proc_macro_derive_panicked =
     proc-macro derive panicked
     .help = message: {$message}

compiler/rustc_expand/src/base.rs

@@ -14,8 +14,7 @@ use rustc_data_structures::fx::FxIndexMap;
 use rustc_data_structures::sync::{self, Lrc};
 use rustc_errors::{DiagCtxt, ErrorGuaranteed, PResult};
 use rustc_feature::Features;
-use rustc_lint_defs::builtin::PROC_MACRO_BACK_COMPAT;
-use rustc_lint_defs::{BufferedEarlyLint, BuiltinLintDiag, RegisteredTools};
+use rustc_lint_defs::{BufferedEarlyLint, RegisteredTools};
 use rustc_parse::{parser, MACRO_ARGUMENTS};
 use rustc_session::config::CollapseMacroDebuginfo;
 use rustc_session::{parse::ParseSess, Limit, Session};
@@ -1330,80 +1329,63 @@ pub fn parse_macro_name_and_helper_attrs(
     Some((trait_ident.name, proc_attrs))
 }
 
-/// This nonterminal looks like some specific enums from
-/// `proc-macro-hack` and `procedural-masquerade` crates.
-/// We need to maintain some special pretty-printing behavior for them due to incorrect
-/// asserts in old versions of those crates and their wide use in the ecosystem.
-/// See issue #73345 for more details.
+/// If this item looks like a specific enums from `rental`, emit a fatal error.
+/// See #73345 and #83125 for more details.
 /// FIXME(#73933): Remove this eventually.
-fn pretty_printing_compatibility_hack(item: &Item, sess: &Session) -> bool {
+fn pretty_printing_compatibility_hack(item: &Item, sess: &Session) {
     let name = item.ident.name;
-    if name == sym::ProceduralMasqueradeDummyType {
-        if let ast::ItemKind::Enum(enum_def, _) = &item.kind {
-            if let [variant] = &*enum_def.variants {
-                if variant.ident.name == sym::Input {
-                    let filename = sess.source_map().span_to_filename(item.ident.span);
-                    if let FileName::Real(real) = filename {
-                        if let Some(c) = real
-                            .local_path()
-                            .unwrap_or(Path::new(""))
-                            .components()
-                            .flat_map(|c| c.as_os_str().to_str())
-                            .find(|c| c.starts_with("rental") || c.starts_with("allsorts-rental"))
-                        {
-                            let crate_matches = if c.starts_with("allsorts-rental") {
-                                true
-                            } else {
-                                let mut version = c.trim_start_matches("rental-").split('.');
-                                version.next() == Some("0")
-                                    && version.next() == Some("5")
-                                    && version
-                                        .next()
-                                        .and_then(|c| c.parse::<u32>().ok())
-                                        .is_some_and(|v| v < 6)
-                            };
-
-                            if crate_matches {
-                                sess.psess.buffer_lint(
-                                    PROC_MACRO_BACK_COMPAT,
-                                    item.ident.span,
-                                    ast::CRATE_NODE_ID,
-                                    BuiltinLintDiag::ProcMacroBackCompat {
-                                        crate_name: "rental".to_string(),
-                                        fixed_version: "0.5.6".to_string(),
-                                    },
-                                );
-                                return true;
-                            }
-                        }
-                    }
-                }
-            }
+    if name == sym::ProceduralMasqueradeDummyType
+        && let ast::ItemKind::Enum(enum_def, _) = &item.kind
+        && let [variant] = &*enum_def.variants
+        && variant.ident.name == sym::Input
+        && let FileName::Real(real) = sess.source_map().span_to_filename(item.ident.span)
+        && let Some(c) = real
+            .local_path()
+            .unwrap_or(Path::new(""))
+            .components()
+            .flat_map(|c| c.as_os_str().to_str())
+            .find(|c| c.starts_with("rental") || c.starts_with("allsorts-rental"))
+    {
+        let crate_matches = if c.starts_with("allsorts-rental") {
+            true
+        } else {
+            let mut version = c.trim_start_matches("rental-").split('.');
+            version.next() == Some("0")
+                && version.next() == Some("5")
+                && version.next().and_then(|c| c.parse::<u32>().ok()).is_some_and(|v| v < 6)
+        };
+
+        if crate_matches {
+            // FIXME: make this translatable
+            #[allow(rustc::untranslatable_diagnostic)]
+            sess.psess.dcx.emit_fatal(errors::ProcMacroBackCompat {
+                crate_name: "rental".to_string(),
+                fixed_version: "0.5.6".to_string(),
+            });
         }
     }
-    false
 }
 
-pub(crate) fn ann_pretty_printing_compatibility_hack(ann: &Annotatable, sess: &Session) -> bool {
+pub(crate) fn ann_pretty_printing_compatibility_hack(ann: &Annotatable, sess: &Session) {
     let item = match ann {
         Annotatable::Item(item) => item,
         Annotatable::Stmt(stmt) => match &stmt.kind {
             ast::StmtKind::Item(item) => item,
-            _ => return false,
+            _ => return,
         },
-        _ => return false,
+        _ => return,
     };
     pretty_printing_compatibility_hack(item, sess)
 }
 
-pub(crate) fn nt_pretty_printing_compatibility_hack(nt: &Nonterminal, sess: &Session) -> bool {
+pub(crate) fn nt_pretty_printing_compatibility_hack(nt: &Nonterminal, sess: &Session) {
     let item = match nt {
         Nonterminal::NtItem(item) => item,
         Nonterminal::NtStmt(stmt) => match &stmt.kind {
             ast::StmtKind::Item(item) => item,
-            _ => return false,
+            _ => return,
         },
-        _ => return false,
+        _ => return,
     };
     pretty_printing_compatibility_hack(item, sess)
 }