Rollup of 8 pull requests

Cargo.lock

@@ -4355,6 +4355,7 @@ name = "rustc_pattern_analysis"
 version = "0.0.0"
 dependencies = [
  "derivative",
+ "rustc-hash",
  "rustc_apfloat",
  "rustc_arena",
  "rustc_data_structures",

compiler/rustc_abi/src/lib.rs

@@ -49,7 +49,14 @@ bitflags! {
                                  | ReprFlags::IS_LINEAR.bits();
     }
 }
-rustc_data_structures::external_bitflags_debug! { ReprFlags }
+
+// This is the same as `rustc_data_structures::external_bitflags_debug` but without the
+// `rustc_data_structures` to make it build on stable.
+impl std::fmt::Debug for ReprFlags {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        bitflags::parser::to_writer(self, f)
+    }
+}
 
 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
 #[cfg_attr(feature = "nightly", derive(Encodable_Generic, Decodable_Generic, HashStable_Generic))]

compiler/rustc_ast/src/ast.rs

@@ -625,7 +625,8 @@ impl Pat {
             | PatKind::Range(..)
             | PatKind::Ident(..)
             | PatKind::Path(..)
-            | PatKind::MacCall(_) => {}
+            | PatKind::MacCall(_)
+            | PatKind::Err(_) => {}
         }
     }
 
@@ -809,6 +810,9 @@ pub enum PatKind {
 
     /// A macro pattern; pre-expansion.
     MacCall(P<MacCall>),
+
+    /// Placeholder for a pattern that wasn't syntactically well formed in some way.
+    Err(ErrorGuaranteed),
 }
 
 /// Whether the `..` is present in a struct fields pattern.

compiler/rustc_ast/src/mut_visit.rs

@@ -1267,7 +1267,7 @@ pub fn noop_visit_pat<T: MutVisitor>(pat: &mut P<Pat>, vis: &mut T) {
     let Pat { id, kind, span, tokens } = pat.deref_mut();
     vis.visit_id(id);
     match kind {
-        PatKind::Wild | PatKind::Rest | PatKind::Never => {}
+        PatKind::Wild | PatKind::Rest | PatKind::Never | PatKind::Err(_) => {}
         PatKind::Ident(_binding_mode, ident, sub) => {
             vis.visit_ident(ident);
             visit_opt(sub, |sub| vis.visit_pat(sub));

compiler/rustc_ast/src/util/literal.rs

@@ -8,7 +8,6 @@ use rustc_lexer::unescape::{
 };
 use rustc_span::symbol::{kw, sym, Symbol};
 use rustc_span::Span;
-use std::ops::Range;
 use std::{ascii, fmt, str};
 
 // Escapes a string, represented as a symbol. Reuses the original symbol,
@@ -39,7 +38,6 @@ pub enum LitError {
     InvalidFloatSuffix,
     NonDecimalFloat(u32),
     IntTooLarge(u32),
-    NulInCStr(Range<usize>),
 }
 
 impl LitKind {
@@ -156,10 +154,7 @@ impl LitKind {
                 let s = symbol.as_str();
                 let mut buf = Vec::with_capacity(s.len());
                 let mut error = Ok(());
-                unescape_c_string(s, Mode::CStr, &mut |span, c| match c {
-                    Ok(CStrUnit::Byte(0) | CStrUnit::Char('\0')) => {
-                        error = Err(LitError::NulInCStr(span));
-                    }
+                unescape_c_string(s, Mode::CStr, &mut |_span, c| match c {
                     Ok(CStrUnit::Byte(b)) => buf.push(b),
                     Ok(CStrUnit::Char(c)) => {
                         buf.extend_from_slice(c.encode_utf8(&mut [0; 4]).as_bytes())
@@ -179,10 +174,7 @@ impl LitKind {
                 // can convert the symbol directly to a `Lrc<u8>` on success.
                 let s = symbol.as_str();
                 let mut error = Ok(());
-                unescape_c_string(s, Mode::RawCStr, &mut |span, c| match c {
-                    Ok(CStrUnit::Byte(0) | CStrUnit::Char('\0')) => {
-                        error = Err(LitError::NulInCStr(span));
-                    }
+                unescape_c_string(s, Mode::RawCStr, &mut |_, c| match c {
                     Ok(_) => {}
                     Err(err) => {
                         if err.is_fatal() {

compiler/rustc_ast/src/visit.rs

@@ -568,7 +568,7 @@ pub fn walk_pat<'a, V: Visitor<'a>>(visitor: &mut V, pattern: &'a Pat) {
             walk_list!(visitor, visit_expr, lower_bound);
             walk_list!(visitor, visit_expr, upper_bound);
         }
-        PatKind::Wild | PatKind::Rest | PatKind::Never => {}
+        PatKind::Wild | PatKind::Rest | PatKind::Never | PatKind::Err(_) => {}
         PatKind::Tuple(elems) | PatKind::Slice(elems) | PatKind::Or(elems) => {
             walk_list!(visitor, visit_pat, elems);
         }

compiler/rustc_ast_lowering/src/pat.rs

@@ -109,6 +109,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                     // return inner to be processed in next loop
                     PatKind::Paren(inner) => pattern = inner,
                     PatKind::MacCall(_) => panic!("{:?} shouldn't exist here", pattern.span),
+                    PatKind::Err(guar) => break hir::PatKind::Err(*guar),
                 }
             };
 

compiler/rustc_ast_pretty/src/pprust/state.rs

@@ -1519,6 +1519,11 @@ impl<'a> State<'a> {
                 self.pclose();
             }
             PatKind::MacCall(m) => self.print_mac(m),
+            PatKind::Err(_) => {
+                self.popen();
+                self.word("/*ERROR*/");
+                self.pclose();
+            }
         }
         self.ann.post(self, AnnNode::Pat(pat))
     }

compiler/rustc_expand/messages.ftl

@@ -16,6 +16,9 @@ expand_attributes_wrong_form =
 expand_cannot_be_name_of_macro =
     `{$trait_ident}` cannot be a name of {$macro_type} macro
 
+expand_collapse_debuginfo_illegal =
+    illegal value for attribute #[collapse_debuginfo(no|external|yes)]
+
 expand_count_repetition_misplaced =
     `count` can not be placed inside the inner-most repetition
 

compiler/rustc_expand/src/base.rs

@@ -1,5 +1,6 @@
 #![deny(rustc::untranslatable_diagnostic)]
 
+use crate::base::ast::NestedMetaItem;
 use crate::errors;
 use crate::expand::{self, AstFragment, Invocation};
 use crate::module::DirOwnership;
@@ -19,6 +20,7 @@ use rustc_feature::Features;
 use rustc_lint_defs::builtin::PROC_MACRO_BACK_COMPAT;
 use rustc_lint_defs::{BufferedEarlyLint, BuiltinLintDiagnostics, RegisteredTools};
 use rustc_parse::{parser, MACRO_ARGUMENTS};
+use rustc_session::config::CollapseMacroDebuginfo;
 use rustc_session::errors::report_lit_error;
 use rustc_session::{parse::ParseSess, Limit, Session};
 use rustc_span::def_id::{CrateNum, DefId, LocalDefId};
@@ -761,6 +763,55 @@ impl SyntaxExtension {
         }
     }
 
+    fn collapse_debuginfo_by_name(sess: &Session, attr: &Attribute) -> CollapseMacroDebuginfo {
+        use crate::errors::CollapseMacroDebuginfoIllegal;
+        // #[collapse_debuginfo] without enum value (#[collapse_debuginfo(no/external/yes)])
+        // considered as `yes`
+        attr.meta_item_list().map_or(CollapseMacroDebuginfo::Yes, |l| {
+            let [NestedMetaItem::MetaItem(item)] = &l[..] else {
+                sess.dcx().emit_err(CollapseMacroDebuginfoIllegal { span: attr.span });
+                return CollapseMacroDebuginfo::Unspecified;
+            };
+            if !item.is_word() {
+                sess.dcx().emit_err(CollapseMacroDebuginfoIllegal { span: item.span });
+                CollapseMacroDebuginfo::Unspecified
+            } else {
+                match item.name_or_empty() {
+                    sym::no => CollapseMacroDebuginfo::No,
+                    sym::external => CollapseMacroDebuginfo::External,
+                    sym::yes => CollapseMacroDebuginfo::Yes,
+                    _ => {
+                        sess.dcx().emit_err(CollapseMacroDebuginfoIllegal { span: item.span });
+                        CollapseMacroDebuginfo::Unspecified
+                    }
+                }
+            }
+        })
+    }
+
+    /// if-ext - if macro from different crate (related to callsite code)
+    /// | cmd \ attr    | no  | (unspecified) | external | yes |
+    /// | no            | no  | no            | no       | no  |
+    /// | (unspecified) | no  | no            | if-ext   | yes |
+    /// | external      | no  | if-ext        | if-ext   | yes |
+    /// | yes           | yes | yes           | yes      | yes |
+    fn get_collapse_debuginfo(sess: &Session, attrs: &[ast::Attribute], is_local: bool) -> bool {
+        let collapse_debuginfo_attr = attr::find_by_name(attrs, sym::collapse_debuginfo)
+            .map(|v| Self::collapse_debuginfo_by_name(sess, v))
+            .unwrap_or(CollapseMacroDebuginfo::Unspecified);
+        let flag = sess.opts.unstable_opts.collapse_macro_debuginfo;
+        let attr = collapse_debuginfo_attr;
+        let ext = !is_local;
+        #[rustfmt::skip]
+        let collapse_table = [
+            [false, false, false, false],
+            [false, false, ext,   true],
+            [false, ext,   ext,   true],
+            [true,  true,  true,  true],
+        ];
+        collapse_table[flag as usize][attr as usize]
+    }
+
     /// Constructs a syntax extension with the given properties
     /// and other properties converted from attributes.
     pub fn new(
@@ -772,6 +823,7 @@ impl SyntaxExtension {
         edition: Edition,
         name: Symbol,
         attrs: &[ast::Attribute],
+        is_local: bool,
     ) -> SyntaxExtension {
         let allow_internal_unstable =
             attr::allow_internal_unstable(sess, attrs).collect::<Vec<Symbol>>();
@@ -780,8 +832,8 @@ impl SyntaxExtension {
         let local_inner_macros = attr::find_by_name(attrs, sym::macro_export)
             .and_then(|macro_export| macro_export.meta_item_list())
             .is_some_and(|l| attr::list_contains_name(&l, sym::local_inner_macros));
-        let collapse_debuginfo = attr::contains_name(attrs, sym::collapse_debuginfo);
-        tracing::debug!(?local_inner_macros, ?collapse_debuginfo, ?allow_internal_unsafe);
+        let collapse_debuginfo = Self::get_collapse_debuginfo(sess, attrs, is_local);
+        tracing::debug!(?name, ?local_inner_macros, ?collapse_debuginfo, ?allow_internal_unsafe);
 
         let (builtin_name, helper_attrs) = attr::find_by_name(attrs, sym::rustc_builtin_macro)
             .map(|attr| {

compiler/rustc_expand/src/errors.rs

@@ -58,6 +58,13 @@ pub(crate) struct ResolveRelativePath {
     pub path: String,
 }
 
+#[derive(Diagnostic)]
+#[diag(expand_collapse_debuginfo_illegal)]
+pub(crate) struct CollapseMacroDebuginfoIllegal {
+    #[primary_span]
+    pub span: Span,
+}
+
 #[derive(Diagnostic)]
 #[diag(expand_macro_const_stability)]
 pub(crate) struct MacroConstStability {

compiler/rustc_expand/src/mbe/macro_rules.rs

@@ -367,6 +367,7 @@ pub fn compile_declarative_macro(
             edition,
             def.ident.name,
             &def.attrs,
+            def.id != DUMMY_NODE_ID,
         )
     };
     let dummy_syn_ext = || (mk_syn_ext(Box::new(macro_rules_dummy_expander)), Vec::new());

compiler/rustc_feature/src/builtin_attrs.rs

@@ -469,7 +469,7 @@ pub const BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[
 
     // `#[collapse_debuginfo]`
     gated!(
-        collapse_debuginfo, Normal, template!(Word), WarnFollowing,
+        collapse_debuginfo, Normal, template!(Word, List: "no|external|yes"), ErrorFollowing,
         experimental!(collapse_debuginfo)
     ),
 

compiler/rustc_hir/src/hir.rs

@@ -1015,7 +1015,7 @@ impl<'hir> Pat<'hir> {
 
         use PatKind::*;
         match self.kind {
-            Wild | Never | Lit(_) | Range(..) | Binding(.., None) | Path(_) => true,
+            Wild | Never | Lit(_) | Range(..) | Binding(.., None) | Path(_) | Err(_) => true,
             Box(s) | Ref(s, _) | Binding(.., Some(s)) => s.walk_short_(it),
             Struct(_, fields, _) => fields.iter().all(|field| field.pat.walk_short_(it)),
             TupleStruct(_, s, _) | Tuple(s, _) | Or(s) => s.iter().all(|p| p.walk_short_(it)),
@@ -1042,7 +1042,7 @@ impl<'hir> Pat<'hir> {
 
         use PatKind::*;
         match self.kind {
-            Wild | Never | Lit(_) | Range(..) | Binding(.., None) | Path(_) => {}
+            Wild | Never | Lit(_) | Range(..) | Binding(.., None) | Path(_) | Err(_) => {}
             Box(s) | Ref(s, _) | Binding(.., Some(s)) => s.walk_(it),
             Struct(_, fields, _) => fields.iter().for_each(|field| field.pat.walk_(it)),
             TupleStruct(_, s, _) | Tuple(s, _) | Or(s) => s.iter().for_each(|p| p.walk_(it)),
@@ -1205,6 +1205,9 @@ pub enum PatKind<'hir> {
     /// PatKind::Slice([Binding(a), Binding(b)], Some(Wild), [Binding(c), Binding(d)])
     /// ```
     Slice(&'hir [Pat<'hir>], Option<&'hir Pat<'hir>>, &'hir [Pat<'hir>]),
+
+    /// A placeholder for a pattern that wasn't well formed in some way.
+    Err(ErrorGuaranteed),
 }
 
 /// A statement.

compiler/rustc_hir/src/intravisit.rs

@@ -655,7 +655,7 @@ pub fn walk_pat<'v, V: Visitor<'v>>(visitor: &mut V, pattern: &'v Pat<'v>) {
             walk_list!(visitor, visit_expr, lower_bound);
             walk_list!(visitor, visit_expr, upper_bound);
         }
-        PatKind::Never | PatKind::Wild => (),
+        PatKind::Never | PatKind::Wild | PatKind::Err(_) => (),
         PatKind::Slice(prepatterns, ref slice_pattern, postpatterns) => {
             walk_list!(visitor, visit_pat, prepatterns);
             walk_list!(visitor, visit_pat, slice_pattern);

compiler/rustc_hir_analysis/src/check/region.rs

@@ -681,7 +681,8 @@ fn resolve_local<'tcx>(
             | PatKind::Never
             | PatKind::Path(_)
             | PatKind::Lit(_)
-            | PatKind::Range(_, _, _) => false,
+            | PatKind::Range(_, _, _)
+            | PatKind::Err(_) => false,
         }
     }
 

compiler/rustc_hir_pretty/src/lib.rs

@@ -1838,6 +1838,11 @@ impl<'a> State<'a> {
                 self.commasep(Inconsistent, after, |s, p| s.print_pat(p));
                 self.word("]");
             }
+            PatKind::Err(_) => {
+                self.popen();
+                self.word("/*ERROR*/");
+                self.pclose();
+            }
         }
         self.ann.post(self, AnnNode::Pat(pat))
     }