Auto merge of #155209 - JonathanBrouwer:attr_cleanup2, r=jdonszelmann

Post-attribute ports cleanup pt. 1 (again)

This is a re-implementation of most (but not all) of #154808

The code is the same as in that PR, other than a few changes, I'll leave comments where I changed things.
I did re-implement most of the commits rather than cherry-picking, so it's probably good to check the entire diff regardless

r? @jdonszelmann

Author: bors

compiler/rustc_attr_parsing/src/validate_attr.rs

@@ -8,8 +8,8 @@ use rustc_ast::tokenstream::DelimSpan;
 use rustc_ast::{
     self as ast, AttrArgs, Attribute, DelimArgs, MetaItem, MetaItemInner, MetaItemKind, Safety,
 };
-use rustc_errors::{Applicability, FatalError, PResult};
-use rustc_feature::{AttributeTemplate, BUILTIN_ATTRIBUTE_MAP, BuiltinAttribute};
+use rustc_errors::{Applicability, PResult};
+use rustc_feature::{AttributeTemplate, BUILTIN_ATTRIBUTE_MAP, BuiltinAttribute, template};
 use rustc_hir::AttrPath;
 use rustc_hir::lints::AttributeLintKind;
 use rustc_parse::parse_in;
@@ -30,15 +30,22 @@ pub fn check_attr(psess: &ParseSess, attr: &Attribute) {
 
     // Check input tokens for built-in and key-value attributes.
     match builtin_attr_info {
-        // `rustc_dummy` doesn't have any restrictions specific to built-in attributes.
-        Some(BuiltinAttribute { name, template, .. }) => {
+        Some(BuiltinAttribute { name, .. }) => {
             if AttributeParser::<Late>::is_parsed_attribute(slice::from_ref(&name)) {
                 return;
             }
             match parse_meta(psess, attr) {
                 // Don't check safety again, we just did that
                 Ok(meta) => {
-                    check_builtin_meta_item(psess, &meta, attr.style, *name, *template, false)
+                    // FIXME The only unparsed builtin attributes that are left are the lint attributes, so we can hardcode the template here
+                    let lint_attrs = [sym::forbid, sym::allow, sym::warn, sym::deny, sym::expect];
+                    assert!(lint_attrs.contains(name));
+
+                    let template = template!(
+                        List: &["lint1", "lint1, lint2, ...", r#"lint1, lint2, lint3, reason = "...""#],
+                        "https://doc.rust-lang.org/reference/attributes/diagnostics.html#lint-check-attributes"
+                    );
+                    check_builtin_meta_item(psess, &meta, attr.style, *name, template, false)
                 }
                 Err(err) => {
                     err.emit();
@@ -169,7 +176,7 @@ pub fn check_builtin_meta_item(
     }
 }
 
-fn emit_malformed_attribute(
+pub fn emit_malformed_attribute(
     psess: &ParseSess,
     style: ast::AttrStyle,
     span: Span,
@@ -231,15 +238,3 @@ fn emit_malformed_attribute(
         err.emit();
     }
 }
-
-pub fn emit_fatal_malformed_builtin_attribute(
-    psess: &ParseSess,
-    attr: &Attribute,
-    name: Symbol,
-) -> ! {
-    let template = BUILTIN_ATTRIBUTE_MAP.get(&name).expect("builtin attr defined").template;
-    emit_malformed_attribute(psess, attr.style, attr.span, name, template);
-    // This is fatal, otherwise it will likely cause a cascade of other errors
-    // (and an error here is expected to be very rare).
-    FatalError.raise()
-}

compiler/rustc_expand/src/module.rs

@@ -2,12 +2,14 @@ use std::iter::once;
 use std::path::{self, Path, PathBuf};
 
 use rustc_ast::{AttrVec, Attribute, Inline, Item, ModSpans};
-use rustc_attr_parsing::validate_attr;
+use rustc_attr_parsing::validate_attr::emit_malformed_attribute;
 use rustc_errors::{Diag, ErrorGuaranteed};
+use rustc_feature::template;
 use rustc_parse::lexer::StripTokens;
 use rustc_parse::{exp, new_parser_from_file, unwrap_or_emit_fatal};
 use rustc_session::Session;
 use rustc_session::parse::ParseSess;
+use rustc_span::fatal_error::FatalError;
 use rustc_span::{Ident, Span, sym};
 use thin_vec::ThinVec;
 
@@ -184,6 +186,7 @@ pub(crate) fn mod_file_path_from_attr(
     attrs: &[Attribute],
     dir_path: &Path,
 ) -> Option<PathBuf> {
+    // FIXME(154781) use a parsed attribute here
     // Extract path string from first `#[path = "path_string"]` attribute.
     let first_path = attrs.iter().find(|at| at.has_name(sym::path))?;
     let Some(path_sym) = first_path.value_str() else {
@@ -195,7 +198,17 @@ pub(crate) fn mod_file_path_from_attr(
         // Usually bad forms are checked during semantic analysis via
         // `TyCtxt::check_mod_attrs`), but by the time that runs the macro
         // is expanded, and it doesn't give an error.
-        validate_attr::emit_fatal_malformed_builtin_attribute(&sess.psess, first_path, sym::path);
+        emit_malformed_attribute(
+            &sess.psess,
+            first_path.style,
+            first_path.span,
+            sym::path,
+            template!(
+                NameValueStr: "file",
+                "https://doc.rust-lang.org/reference/items/modules.html#the-path-attribute"
+            ),
+        );
+        FatalError.raise()
     };
 
     let path_str = path_sym.as_str();