Add lint to deny diagnostics composed of static strings

compiler/rustc_builtin_macros/messages.ftl

@@ -149,6 +149,25 @@ builtin_macros_format_pos_mismatch = {$n} positional {$n ->
     [one] argument
     *[more] arguments
     } in format string, but {$desc}
+
 builtin_macros_offset_of_expected_field = expected field
 
 builtin_macros_offset_of_expected_two_args = expected 2 arguments
+
+builtin_macros_test_case_non_item = `#[test_case]` attribute is only allowed on items
+
+builtin_macros_test_bad_fn = {$kind} functions cannot be used for tests
+    .label = `{$kind}` because of this
+
+builtin_macros_asm_explicit_register_name = explicit register arguments cannot have names
+
+builtin_macros_asm_mutually_exclusive = the `{$opt1}` and `{$opt2}` options are mutually exclusive
+
+builtin_macros_asm_pure_combine = the `pure` option must be combined with either `nomem` or `readonly`
+
+builtin_macros_asm_pure_no_output = asm with the `pure` option must have at least one output
+
+builtin_macros_asm_modifier_invalid = asm template modifier must be a single character
+
+builtin_macros_test_runner_invalid = `test_runner` argument must be a path
+builtin_macros_test_runner_nargs = `#![test_runner(..)]` accepts exactly 1 argument

compiler/rustc_builtin_macros/src/asm.rs

@@ -15,6 +15,8 @@ use rustc_span::{InnerSpan, Span};
 use rustc_target::asm::InlineAsmArch;
 use smallvec::smallvec;
 
+use crate::errors;
+
 pub struct AsmArgs {
     pub templates: Vec<P<ast::Expr>>,
     pub operands: Vec<(ast::InlineAsmOperand, Span)>,
@@ -205,7 +207,7 @@ pub fn parse_asm_args<'a>(
         // of the argument available.
         if explicit_reg {
             if name.is_some() {
-                diag.struct_span_err(span, "explicit register arguments cannot have names").emit();
+                diag.emit_err(errors::AsmExplicitRegisterName { span });
             }
             args.reg_args.insert(slot);
         } else if let Some(name) = name {
@@ -240,25 +242,19 @@ pub fn parse_asm_args<'a>(
         && args.options.contains(ast::InlineAsmOptions::READONLY)
     {
         let spans = args.options_spans.clone();
-        diag.struct_span_err(spans, "the `nomem` and `readonly` options are mutually exclusive")
-            .emit();
+        diag.emit_err(errors::AsmMutuallyExclusive { spans, opt1: "nomem", opt2: "readonly" });
     }
     if args.options.contains(ast::InlineAsmOptions::PURE)
         && args.options.contains(ast::InlineAsmOptions::NORETURN)
     {
         let spans = args.options_spans.clone();
-        diag.struct_span_err(spans, "the `pure` and `noreturn` options are mutually exclusive")
-            .emit();
+        diag.emit_err(errors::AsmMutuallyExclusive { spans, opt1: "pure", opt2: "noreturn" });
     }
     if args.options.contains(ast::InlineAsmOptions::PURE)
         && !args.options.intersects(ast::InlineAsmOptions::NOMEM | ast::InlineAsmOptions::READONLY)
     {
         let spans = args.options_spans.clone();
-        diag.struct_span_err(
-            spans,
-            "the `pure` option must be combined with either `nomem` or `readonly`",
-        )
-        .emit();
+        diag.emit_err(errors::AsmPureCombine { spans });
     }
 
     let mut have_real_output = false;
@@ -285,11 +281,7 @@ pub fn parse_asm_args<'a>(
         }
     }
     if args.options.contains(ast::InlineAsmOptions::PURE) && !have_real_output {
-        diag.struct_span_err(
-            args.options_spans.clone(),
-            "asm with the `pure` option must have at least one output",
-        )
-        .emit();
+        diag.emit_err(errors::AsmPureNoOutput { spans: args.options_spans.clone() });
     }
     if args.options.contains(ast::InlineAsmOptions::NORETURN) && !outputs_sp.is_empty() {
         let err = diag
@@ -705,11 +697,7 @@ fn expand_preparsed_asm(ecx: &mut ExtCtxt<'_>, args: AsmArgs) -> Option<ast::Inl
                             .ty_span
                             .map(|sp| template_sp.from_inner(InnerSpan::new(sp.start, sp.end)))
                             .unwrap_or(template_sp);
-                        ecx.struct_span_err(
-                            span,
-                            "asm template modifier must be a single character",
-                        )
-                        .emit();
+                        ecx.emit_err(errors::AsmModifierInvalid { span });
                         modifier = None;
                     }
 

compiler/rustc_builtin_macros/src/errors.rs

@@ -551,3 +551,71 @@ pub(crate) struct FormatPositionalMismatch {
     #[subdiagnostic]
     pub(crate) highlight: SingleLabelManySpans,
 }
+
+#[derive(Diagnostic)]
+#[diag(builtin_macros_test_case_non_item)]
+pub(crate) struct TestCaseNonItem {
+    #[primary_span]
+    pub(crate) span: Span,
+}
+
+#[derive(Diagnostic)]
+#[diag(builtin_macros_test_bad_fn)]
+pub(crate) struct TestBadFn {
+    #[primary_span]
+    pub(crate) span: Span,
+    #[label]
+    pub(crate) cause: Span,
+    pub(crate) kind: &'static str,
+}
+
+#[derive(Diagnostic)]
+#[diag(builtin_macros_asm_explicit_register_name)]
+pub(crate) struct AsmExplicitRegisterName {
+    #[primary_span]
+    pub(crate) span: Span,
+}
+
+#[derive(Diagnostic)]
+#[diag(builtin_macros_asm_mutually_exclusive)]
+pub(crate) struct AsmMutuallyExclusive {
+    #[primary_span]
+    pub(crate) spans: Vec<Span>,
+    pub(crate) opt1: &'static str,
+    pub(crate) opt2: &'static str,
+}
+
+#[derive(Diagnostic)]
+#[diag(builtin_macros_asm_pure_combine)]
+pub(crate) struct AsmPureCombine {
+    #[primary_span]
+    pub(crate) spans: Vec<Span>,
+}
+
+#[derive(Diagnostic)]
+#[diag(builtin_macros_asm_pure_no_output)]
+pub(crate) struct AsmPureNoOutput {
+    #[primary_span]
+    pub(crate) spans: Vec<Span>,
+}
+
+#[derive(Diagnostic)]
+#[diag(builtin_macros_asm_modifier_invalid)]
+pub(crate) struct AsmModifierInvalid {
+    #[primary_span]
+    pub(crate) span: Span,
+}
+
+#[derive(Diagnostic)]
+#[diag(builtin_macros_test_runner_invalid)]
+pub(crate) struct TestRunnerInvalid {
+    #[primary_span]
+    pub(crate) span: Span,
+}
+
+#[derive(Diagnostic)]
+#[diag(builtin_macros_test_runner_nargs)]
+pub(crate) struct TestRunnerNargs {
+    #[primary_span]
+    pub(crate) span: Span,
+}

compiler/rustc_builtin_macros/src/test.rs

@@ -1,3 +1,4 @@
+use crate::errors;
 /// The expansion from a test function to the appropriate test struct for libtest
 /// Ideally, this code would be in libtest but for efficiency and error messages it lives here.
 use crate::util::{check_builtin_macro_attribute, warn_on_duplicate_attribute};
@@ -40,12 +41,7 @@ pub fn expand_test_case(
             unreachable!()
         },
         _ => {
-            ecx.struct_span_err(
-                anno_item.span(),
-                "`#[test_case]` attribute is only allowed on items",
-            )
-            .emit();
-
+            ecx.emit_err(errors::TestCaseNonItem { span: anno_item.span() });
             return vec![];
         }
     };
@@ -533,15 +529,11 @@ fn has_test_signature(cx: &ExtCtxt<'_>, i: &ast::Item) -> bool {
     match &i.kind {
         ast::ItemKind::Fn(box ast::Fn { sig, generics, .. }) => {
             if let ast::Unsafe::Yes(span) = sig.header.unsafety {
-                sd.struct_span_err(i.span, "unsafe functions cannot be used for tests")
-                    .span_label(span, "`unsafe` because of this")
-                    .emit();
+                sd.emit_err(errors::TestBadFn { span: i.span, cause: span, kind: "unsafe" });
                 return false;
             }
             if let ast::Async::Yes { span, .. } = sig.header.asyncness {
-                sd.struct_span_err(i.span, "async functions cannot be used for tests")
-                    .span_label(span, "`async` because of this")
-                    .emit();
+                sd.emit_err(errors::TestBadFn { span: i.span, cause: span, kind: "async" });
                 return false;
             }
 

compiler/rustc_builtin_macros/src/test_harness.rs

@@ -19,6 +19,8 @@ use tracing::debug;
 
 use std::{iter, mem};
 
+use crate::errors;
+
 #[derive(Clone)]
 struct Test {
     span: Span,
@@ -385,11 +387,11 @@ fn get_test_runner(sd: &rustc_errors::Handler, krate: &ast::Crate) -> Option<ast
         [single] => match single.meta_item() {
             Some(meta_item) if meta_item.is_word() => return Some(meta_item.path.clone()),
             _ => {
-                sd.struct_span_err(span, "`test_runner` argument must be a path").emit();
+                sd.emit_err(errors::TestRunnerInvalid { span });
             }
         },
         _ => {
-            sd.struct_span_err(span, "`#![test_runner(..)]` accepts exactly 1 argument").emit();
+            sd.emit_err(errors::TestRunnerNargs { span });
         }
     }
     None

compiler/rustc_codegen_ssa/messages.ftl

@@ -291,3 +291,16 @@ codegen_ssa_invalid_monomorphization_unsupported_cast = invalid monomorphization
 codegen_ssa_invalid_monomorphization_unsupported_operation = invalid monomorphization of `{$name}` intrinsic: unsupported operation on `{$in_ty}` with element `{$in_elem}`
 
 codegen_ssa_invalid_monomorphization_expected_vector_element_type = invalid monomorphization of `{$name}` intrinsic: expected element type `{$expected_element}` of vector type `{$vector_type}` to be a signed or unsigned integer type
+
+codegen_ssa_invalid_no_sanitize = invalid argument for `no_sanitize`
+    .note = expected one of: `address`, `cfi`, `hwaddress`, `kcfi`, `memory`, `memtag`, `shadow-call-stack`, or `thread`
+
+codegen_ssa_invalid_link_ordinal_nargs = incorrect number of arguments to `#[link_ordinal]`
+    .note = the attribute requires exactly one argument
+
+codegen_ssa_illegal_link_ordinal_format = illegal ordinal format in `link_ordinal`
+    .note = an unsuffixed integer value, e.g., `1`, is expected
+
+codegen_ssa_target_feature_safe_trait = `#[target_feature(..)]` cannot be applied to safe trait method
+    .label = cannot be applied to safe trait method
+    .label_def = not an `unsafe` function

compiler/rustc_codegen_ssa/src/codegen_attrs.rs

@@ -14,6 +14,7 @@ use rustc_span::symbol::Ident;
 use rustc_span::{sym, Span};
 use rustc_target::spec::{abi, SanitizerSet};
 
+use crate::errors;
 use crate::target_features::from_target_feature;
 use crate::{errors::ExpectedUsedSymbol, target_features::check_target_feature_trait_unsafe};
 
@@ -334,10 +335,7 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, did: LocalDefId) -> CodegenFnAttrs {
                                 codegen_fn_attrs.no_sanitize |= SanitizerSet::HWADDRESS
                             }
                             _ => {
-                                tcx.sess
-                                    .struct_span_err(item.span(), "invalid argument for `no_sanitize`")
-                                    .note("expected one of: `address`, `cfi`, `hwaddress`, `kcfi`, `memory`, `memtag`, `shadow-call-stack`, or `thread`")
-                                    .emit();
+                                tcx.sess.emit_err(errors::InvalidNoSanitize { span: item.span() });
                             }
                         }
                     }
@@ -608,10 +606,7 @@ fn check_link_ordinal(tcx: TyCtxt<'_>, attr: &ast::Attribute) -> Option<u16> {
     let sole_meta_list = match meta_item_list {
         Some([item]) => item.lit(),
         Some(_) => {
-            tcx.sess
-                .struct_span_err(attr.span, "incorrect number of arguments to `#[link_ordinal]`")
-                .note("the attribute requires exactly one argument")
-                .emit();
+            tcx.sess.emit_err(errors::InvalidLinkOrdinalNargs { span: attr.span });
             return None;
         }
         _ => None,
@@ -642,10 +637,7 @@ fn check_link_ordinal(tcx: TyCtxt<'_>, attr: &ast::Attribute) -> Option<u16> {
             None
         }
     } else {
-        tcx.sess
-            .struct_span_err(attr.span, "illegal ordinal format in `link_ordinal`")
-            .note("an unsuffixed integer value, e.g., `1`, is expected")
-            .emit();
+        tcx.sess.emit_err(errors::InvalidLinkOrdinalFormat { span: attr.span });
         None
     }
 }

compiler/rustc_codegen_ssa/src/errors.rs

@@ -981,3 +981,37 @@ impl IntoDiagnosticArg for ExpectedPointerMutability {
         }
     }
 }
+
+#[derive(Diagnostic)]
+#[diag(codegen_ssa_invalid_no_sanitize)]
+#[note]
+pub struct InvalidNoSanitize {
+    #[primary_span]
+    pub span: Span,
+}
+
+#[derive(Diagnostic)]
+#[diag(codegen_ssa_invalid_link_ordinal_nargs)]
+#[note]
+pub struct InvalidLinkOrdinalNargs {
+    #[primary_span]
+    pub span: Span,
+}
+
+#[derive(Diagnostic)]
+#[diag(codegen_ssa_illegal_link_ordinal_format)]
+#[note]
+pub struct InvalidLinkOrdinalFormat {
+    #[primary_span]
+    pub span: Span,
+}
+
+#[derive(Diagnostic)]
+#[diag(codegen_ssa_target_feature_safe_trait)]
+pub struct TargetFeatureSafeTrait {
+    #[primary_span]
+    #[label]
+    pub span: Span,
+    #[label(codegen_ssa_label_def)]
+    pub def: Span,
+}

compiler/rustc_codegen_ssa/src/target_features.rs

@@ -1,3 +1,4 @@
+use crate::errors;
 use rustc_ast::ast;
 use rustc_attr::InstructionSetAttr;
 use rustc_data_structures::fx::FxHashMap;
@@ -443,14 +444,10 @@ pub fn check_target_feature_trait_unsafe(tcx: TyCtxt<'_>, id: LocalDefId, attr_s
     if let DefKind::AssocFn = tcx.def_kind(id) {
         let parent_id = tcx.local_parent(id);
         if let DefKind::Trait | DefKind::Impl { of_trait: true } = tcx.def_kind(parent_id) {
-            tcx.sess
-                .struct_span_err(
-                    attr_span,
-                    "`#[target_feature(..)]` cannot be applied to safe trait method",
-                )
-                .span_label(attr_span, "cannot be applied to safe trait method")
-                .span_label(tcx.def_span(id), "not an `unsafe` function")
-                .emit();
+            tcx.sess.emit_err(errors::TargetFeatureSafeTrait {
+                span: attr_span,
+                def: tcx.def_span(id),
+            });
         }
     }
 }

compiler/rustc_expand/messages.ftl

@@ -136,3 +136,7 @@ expand_proc_macro_panicked =
 
 expand_proc_macro_derive_tokens =
     proc-macro derive produced unparsable tokens
+
+expand_duplicate_matcher_binding = duplicate matcher binding
+    .label = duplicate binding
+    .label2 = previous binding

compiler/rustc_expand/src/errors.rs

@@ -397,3 +397,13 @@ pub struct ProcMacroDeriveTokens {
     #[primary_span]
     pub span: Span,
 }
+
+#[derive(Diagnostic)]
+#[diag(expand_duplicate_matcher_binding)]
+pub struct DuplicateMatcherBinding {
+    #[primary_span]
+    #[label]
+    pub span: Span,
+    #[label(expand_label2)]
+    pub prev: Span,
+}

compiler/rustc_expand/src/mbe/macro_check.rs

@@ -104,6 +104,7 @@
 //! Kleene operators under which a meta-variable is repeating is the concatenation of the stacks
 //! stored when entering a macro definition starting from the state in which the meta-variable is
 //! bound.
+use crate::errors;
 use crate::mbe::{KleeneToken, TokenTree};
 
 use rustc_ast::token::{Delimiter, Token, TokenKind};
@@ -281,10 +282,7 @@ fn check_binders(
                 // Duplicate binders at the top-level macro definition are errors. The lint is only
                 // for nested macro definitions.
                 sess.span_diagnostic
-                    .struct_span_err(span, "duplicate matcher binding")
-                    .span_label(span, "duplicate binding")
-                    .span_label(prev_info.span, "previous binding")
-                    .emit();
+                    .emit_err(errors::DuplicateMatcherBinding { span, prev: prev_info.span });
                 *valid = false;
             } else {
                 binders.insert(name, BinderInfo { span, ops: ops.into() });