add test to reproduce #137687 and fix it

Author: jdonszelmann

compiler/rustc_attr_data_structures/src/attributes.rs

@@ -175,6 +175,11 @@ pub enum AttributeKind {
         span: Span,
     },
     ConstStabilityIndirect,
+    CrateName {
+        name: Symbol,
+        name_span: Span,
+        style: AttrStyle,
+    },
     Deprecation {
         deprecation: Deprecation,
         span: Span,
@@ -195,3 +200,24 @@ pub enum AttributeKind {
     },
     // tidy-alphabetical-end
 }
+
+impl AttributeKind {
+    pub fn crate_level(&self) -> Option<(AttrStyle, Span)> {
+        match self {
+            AttributeKind::AllowConstFnUnstable(..)
+            | AttributeKind::AllowInternalUnstable(..)
+            | AttributeKind::BodyStability { .. }
+            | AttributeKind::Confusables { .. }
+            | AttributeKind::ConstStability { .. }
+            | AttributeKind::ConstStabilityIndirect
+            | AttributeKind::Deprecation { .. }
+            | AttributeKind::Diagnostic(..)
+            | AttributeKind::DocComment { .. }
+            | AttributeKind::MacroTransparency(..)
+            | AttributeKind::Repr(..)
+            | AttributeKind::Stability { .. } => None,
+
+            AttributeKind::CrateName { style, name_span, .. } => Some((*style, *name_span)),
+        }
+    }
+}

compiler/rustc_attr_parsing/messages.ftl

@@ -87,6 +87,8 @@ attr_parsing_multiple_item =
 attr_parsing_multiple_stability_levels =
     multiple stability levels
 
+attr_parsing_name_value = malformed `{$name}` attribute: expected to be of the form `#[{$name} = ...]`
+
 attr_parsing_non_ident_feature =
     'feature' is not an identifier
 

compiler/rustc_attr_parsing/src/attributes/crate_name.rs

@@ -0,0 +1,42 @@
+use rustc_attr_data_structures::AttributeKind;
+use rustc_span::{Span, Symbol, sym};
+
+use super::SingleAttributeParser;
+use crate::context::AcceptContext;
+use crate::parser::ArgParser;
+use crate::session_diagnostics::{ExpectedNameValue, IncorrectMetaItem, UnusedMultiple};
+
+pub(crate) struct CratenameParser;
+
+impl SingleAttributeParser for CratenameParser {
+    const PATH: &'static [Symbol] = &[sym::crate_name];
+
+    fn on_duplicate(cx: &AcceptContext<'_>, first_span: Span) {
+        // FIXME(jdonszelmann): better duplicate reporting (WIP)
+        cx.emit_err(UnusedMultiple {
+            this: cx.attr_span,
+            other: first_span,
+            name: sym::crate_name,
+        });
+    }
+
+    fn convert(cx: &AcceptContext<'_>, args: &ArgParser<'_>) -> Option<AttributeKind> {
+        if let ArgParser::NameValue(n) = args {
+            if let Some(name) = n.value_as_str() {
+                Some(AttributeKind::CrateName {
+                    name,
+                    name_span: n.value_span,
+                    style: cx.attr_style,
+                })
+            } else {
+                cx.emit_err(IncorrectMetaItem { span: cx.attr_span, suggestion: None });
+
+                None
+            }
+        } else {
+            cx.emit_err(ExpectedNameValue { span: cx.attr_span, name: sym::crate_name });
+
+            None
+        }
+    }
+}

compiler/rustc_attr_parsing/src/attributes/mod.rs

@@ -26,6 +26,7 @@ use crate::parser::ArgParser;
 pub(crate) mod allow_unstable;
 pub(crate) mod cfg;
 pub(crate) mod confusables;
+pub(crate) mod crate_name;
 pub(crate) mod deprecation;
 pub(crate) mod repr;
 pub(crate) mod stability;

compiler/rustc_attr_parsing/src/attributes/util.rs

@@ -1,7 +1,7 @@
-use rustc_ast::attr::{AttributeExt, first_attr_value_str_by_name};
+use rustc_ast::attr::AttributeExt;
 use rustc_attr_data_structures::RustcVersion;
 use rustc_feature::is_builtin_attr_name;
-use rustc_span::{Symbol, sym};
+use rustc_span::Symbol;
 
 /// Parse a rustc version number written inside string literal in an attribute,
 /// like appears in `since = "1.0.0"`. Suffixes like "-dev" and "-nightly" are
@@ -22,7 +22,3 @@ pub fn parse_version(s: Symbol) -> Option<RustcVersion> {
 pub fn is_builtin_attr(attr: &impl AttributeExt) -> bool {
     attr.is_doc_comment() || attr.ident().is_some_and(|ident| is_builtin_attr_name(ident.name))
 }
-
-pub fn find_crate_name(attrs: &[impl AttributeExt]) -> Option<Symbol> {
-    first_attr_value_str_by_name(attrs, sym::crate_name)
-}

compiler/rustc_attr_parsing/src/context.rs

@@ -3,7 +3,7 @@ use std::collections::BTreeMap;
 use std::ops::Deref;
 use std::sync::LazyLock;
 
-use rustc_ast::{self as ast, DelimArgs};
+use rustc_ast::{self as ast, AttrStyle, DelimArgs};
 use rustc_attr_data_structures::AttributeKind;
 use rustc_errors::{DiagCtxtHandle, Diagnostic};
 use rustc_feature::Features;
@@ -14,6 +14,7 @@ use rustc_span::{DUMMY_SP, ErrorGuaranteed, Span, Symbol, sym};
 
 use crate::attributes::allow_unstable::{AllowConstFnUnstableParser, AllowInternalUnstableParser};
 use crate::attributes::confusables::ConfusablesParser;
+use crate::attributes::crate_name::CratenameParser;
 use crate::attributes::deprecation::DeprecationParser;
 use crate::attributes::repr::ReprParser;
 use crate::attributes::stability::{
@@ -76,6 +77,7 @@ attribute_groups!(
 
         // tidy-alphabetical-start
         Single<ConstStabilityIndirectParser>,
+        Single<CratenameParser>,
         Single<DeprecationParser>,
         Single<TransparencyParser>,
         // tidy-alphabetical-end
@@ -89,6 +91,7 @@ pub(crate) struct AcceptContext<'a> {
     pub(crate) group_cx: &'a FinalizeContext<'a>,
     /// The span of the attribute currently being parsed
     pub(crate) attr_span: Span,
+    pub(crate) attr_style: AttrStyle,
 }
 
 impl<'a> AcceptContext<'a> {
@@ -269,6 +272,7 @@ impl<'sess> AttributeParser<'sess> {
                             let cx = AcceptContext {
                                 group_cx: &group_cx,
                                 attr_span: lower_span(attr.span),
+                                attr_style: attr.style,
                             };
 
                             f(&cx, &args)

compiler/rustc_attr_parsing/src/lib.rs

@@ -90,7 +90,7 @@ pub mod parser;
 mod session_diagnostics;
 
 pub use attributes::cfg::*;
-pub use attributes::util::{find_crate_name, is_builtin_attr, parse_version};
+pub use attributes::util::{is_builtin_attr, parse_version};
 pub use context::{AttributeParser, OmitDoc};
 pub use rustc_attr_data_structures::*;
 

compiler/rustc_attr_parsing/src/session_diagnostics.rs

@@ -479,3 +479,11 @@ pub(crate) struct UnrecognizedReprHint {
     #[primary_span]
     pub span: Span,
 }
+
+#[derive(Diagnostic)]
+#[diag(attr_parsing_name_value, code = E0539)]
+pub(crate) struct ExpectedNameValue {
+    #[primary_span]
+    pub span: Span,
+    pub name: Symbol,
+}

compiler/rustc_driver_impl/src/lib.rs

@@ -44,6 +44,7 @@ use rustc_errors::emitter::stderr_destination;
 use rustc_errors::registry::Registry;
 use rustc_errors::{ColorConfig, DiagCtxt, ErrCode, FatalError, PResult, markdown};
 use rustc_feature::find_gated_cfg;
+use rustc_interface::passes::get_crate_name;
 use rustc_interface::util::{self, get_codegen_backend};
 use rustc_interface::{Linker, create_and_enter_global_ctxt, interface, passes};
 use rustc_lint::unerased_lint_store;
@@ -667,7 +668,8 @@ fn print_crate_info(
                     return Compilation::Continue;
                 };
                 let t_outputs = rustc_interface::util::build_output_filenames(attrs, sess);
-                let crate_name = passes::get_crate_name(sess, attrs);
+                let crate_name = get_crate_name(sess, attrs);
+
                 let crate_types = collect_crate_types(sess, attrs);
                 for &style in &crate_types {
                     let fname = rustc_session::output::filename_for_input(
@@ -681,7 +683,7 @@ fn print_crate_info(
                     // no crate attributes, print out an error and exit
                     return Compilation::Continue;
                 };
-                println_info!("{}", passes::get_crate_name(sess, attrs));
+                println_info!("{}", get_crate_name(sess, attrs));
             }
             Cfg => {
                 let mut cfgs = sess

compiler/rustc_interface/src/passes.rs

@@ -6,6 +6,7 @@ use std::sync::{Arc, LazyLock};
 use std::{env, fs, iter};
 
 use rustc_ast as ast;
+use rustc_attr_parsing::{AttributeKind, AttributeParser};
 use rustc_codegen_ssa::traits::CodegenBackend;
 use rustc_data_structures::parallel;
 use rustc_data_structures::steal::Steal;
@@ -32,7 +33,7 @@ use rustc_session::output::{collect_crate_types, filename_for_input};
 use rustc_session::search_paths::PathKind;
 use rustc_session::{Limit, Session};
 use rustc_span::{
-    ErrorGuaranteed, FileName, SourceFileHash, SourceFileHashAlgorithm, Span, Symbol, sym,
+    DUMMY_SP, ErrorGuaranteed, FileName, SourceFileHash, SourceFileHashAlgorithm, Span, Symbol, sym,
 };
 use rustc_target::spec::PanicStrategy;
 use rustc_trait_selection::traits;
@@ -1119,6 +1120,20 @@ pub(crate) fn start_codegen<'tcx>(
     codegen
 }
 
+pub(crate) fn parse_crate_name(
+    sess: &Session,
+    attrs: &[ast::Attribute],
+    limit_diagnostics: bool,
+) -> Option<(Symbol, Span)> {
+    let rustc_hir::Attribute::Parsed(AttributeKind::CrateName { name, name_span, .. }) =
+        AttributeParser::parse_limited(sess, &attrs, sym::crate_name, DUMMY_SP, limit_diagnostics)?
+    else {
+        unreachable!("crate_name is the only attr we could've parsed here");
+    };
+
+    Some((name, name_span))
+}
+
 /// Compute and validate the crate name.
 pub fn get_crate_name(sess: &Session, krate_attrs: &[ast::Attribute]) -> Symbol {
     // We validate *all* occurrences of `#![crate_name]`, pick the first find and
@@ -1128,8 +1143,7 @@ pub fn get_crate_name(sess: &Session, krate_attrs: &[ast::Attribute]) -> Symbol
     // in all code paths that require the crate name very early on, namely before
     // macro expansion.
 
-    let attr_crate_name =
-        validate_and_find_value_str_builtin_attr(sym::crate_name, sess, krate_attrs);
+    let attr_crate_name = parse_crate_name(sess, krate_attrs, false);
 
     let validate = |name, span| {
         rustc_session::output::validate_crate_name(sess, name, span);

compiler/rustc_interface/src/util.rs

@@ -23,6 +23,7 @@ use rustc_target::spec::Target;
 use tracing::info;
 
 use crate::errors;
+use crate::passes::parse_crate_name;
 
 /// Function pointer type that constructs a new CodegenBackend.
 type MakeBackendFn = fn() -> Box<dyn CodegenBackend>;
@@ -485,7 +486,7 @@ pub fn build_output_filenames(attrs: &[ast::Attribute], sess: &Session) -> Outpu
         .opts
         .crate_name
         .clone()
-        .or_else(|| rustc_attr_parsing::find_crate_name(attrs).map(|n| n.to_string()));
+        .or_else(|| parse_crate_name(sess, attrs, true).map(|i| i.0.to_string()));
 
     match sess.io.output_file {
         None => {

compiler/rustc_lint/src/nonstandard_style.rs

@@ -1,8 +1,8 @@
 use rustc_abi::ExternAbi;
-use rustc_attr_parsing::{AttributeKind, AttributeParser, ReprAttr};
+use rustc_attr_parsing::{AttributeKind, AttributeParser, ReprAttr, find_attr};
 use rustc_hir::def::{DefKind, Res};
 use rustc_hir::intravisit::FnKind;
-use rustc_hir::{AttrArgs, AttrItem, Attribute, GenericParamKind, PatExprKind, PatKind};
+use rustc_hir::{Attribute, GenericParamKind, PatExprKind, PatKind};
 use rustc_middle::ty;
 use rustc_session::config::CrateType;
 use rustc_session::{declare_lint, declare_lint_pass};
@@ -342,35 +342,27 @@ impl<'tcx> LateLintPass<'tcx> for NonSnakeCase {
         let crate_ident = if let Some(name) = &cx.tcx.sess.opts.crate_name {
             Some(Ident::from_str(name))
         } else {
-            ast::attr::find_by_name(cx.tcx.hir().attrs(hir::CRATE_HIR_ID), sym::crate_name)
-                .and_then(|attr| {
-                    if let Attribute::Unparsed(n) = attr
-                        && let AttrItem { args: AttrArgs::Eq { eq_span: _, expr: lit }, .. } =
-                            n.as_ref()
-                        && let ast::LitKind::Str(name, ..) = lit.kind
-                    {
-                        // Discard the double quotes surrounding the literal.
-                        let sp = cx
-                            .sess()
-                            .source_map()
-                            .span_to_snippet(lit.span)
-                            .ok()
-                            .and_then(|snippet| {
-                                let left = snippet.find('"')?;
-                                let right = snippet.rfind('"').map(|pos| snippet.len() - pos)?;
-
-                                Some(
-                                    lit.span
-                                        .with_lo(lit.span.lo() + BytePos(left as u32 + 1))
-                                        .with_hi(lit.span.hi() - BytePos(right as u32)),
-                                )
-                            })
-                            .unwrap_or(lit.span);
-
-                        Some(Ident::new(name, sp))
-                    } else {
-                        None
-                    }
+            find_attr!(cx.tcx.hir().attrs(hir::CRATE_HIR_ID), AttributeKind::CrateName{name, name_span,..} => (name, name_span))
+                .and_then(|(&name, &span)| {
+                    // Discard the double quotes surrounding the literal.
+                    let sp = cx
+                        .sess()
+                        .source_map()
+                        .span_to_snippet(span)
+                        .ok()
+                        .and_then(|snippet| {
+                            let left = snippet.find('"')?;
+                            let right = snippet.rfind('"').map(|pos| snippet.len() - pos)?;
+
+                            Some(
+                                span
+                                    .with_lo(span.lo() + BytePos(left as u32 + 1))
+                                    .with_hi(span.hi() - BytePos(right as u32)),
+                            )
+                        })
+                        .unwrap_or(span);
+
+                    Some(Ident::new(name, sp))
                 })
         };
 

compiler/rustc_parse/src/validate_attr.rs

@@ -217,7 +217,9 @@ pub fn check_builtin_meta_item(
 ) {
     // Some special attributes like `cfg` must be checked
     // before the generic check, so we skip them here.
-    let should_skip = |name| name == sym::cfg;
+    //
+    // Also, attributes that have a new-style parser don't need to be checked here anymore
+    let should_skip = |name| name == sym::cfg || name == sym::crate_name;
 
     if !should_skip(name) && !is_attr_template_compatible(&template, &meta.kind) {
         emit_malformed_attribute(psess, style, meta.span, name, template);