add check_unused_messages in tidy

Author: chenyukang

compiler/rustc_hir_analysis/messages.ftl

@@ -72,8 +72,6 @@ hir_analysis_enum_discriminant_overflowed = enum discriminant overflowed
     .label = overflowed on value after {$discr}
     .note = explicitly set `{$item_name} = {$wrapped_discr}` if that is desired outcome
 
-hir_analysis_expected_used_symbol = expected `used`, `used(compiler)` or `used(linker)`
-
 hir_analysis_field_already_declared =
     field `{$field_name}` is already declared
     .label = field already declared

compiler/rustc_infer/messages.ftl

@@ -66,7 +66,6 @@ infer_await_both_futures = consider `await`ing on both `Future`s
 infer_await_future = consider `await`ing on the `Future`
 infer_await_note = calling an async function returns a future
 
-infer_borrowed_too_long = a value of type `{$ty}` is borrowed for too long
 infer_but_calling_introduces = {$has_param_name ->
     [true] `{$param_name}`
     *[false] `fn` parameter
@@ -181,8 +180,6 @@ infer_more_targeted = {$has_param_name ->
 } but calling `{$ident}` introduces an implicit `'static` lifetime requirement
 
 infer_msl_introduces_static = introduces a `'static` lifetime requirement
-infer_msl_trait_note = this has an implicit `'static` lifetime requirement
-infer_msl_trait_sugg = consider relaxing the implicit `'static` requirement
 infer_msl_unmet_req = because this has an unmet lifetime requirement
 infer_need_type_info_in_generator =
     type inside {$generator_kind ->
@@ -229,7 +226,6 @@ infer_prlf_known_limitation = this is a known limitation that will be removed in
 infer_prlf_must_outlive_with_sup = ...must outlive the lifetime `{$sup_symbol}` defined here
 infer_prlf_must_outlive_without_sup = ...must outlive the lifetime defined here
 infer_reborrow = ...so that reference does not outlive borrowed content
-infer_reborrow_upvar = ...so that closure can access `{$name}`
 infer_ref_longer_than_data = in type `{$ty}`, reference has a longer lifetime than the data it references
 
 infer_reference_outlives_referent = ...so that the reference type `{$name}` does not outlive the data it points at

compiler/rustc_monomorphize/messages.ftl

@@ -7,8 +7,6 @@ monomorphize_couldnt_dump_mono_stats =
 monomorphize_encountered_error_while_instantiating =
     the above error was encountered while instantiating `{$formatted_item}`
 
-monomorphize_fatal_error = {$error_message}
-
 monomorphize_large_assignments =
     moving {$size} bytes
     .label = value moved from here

compiler/rustc_parse/messages.ftl

@@ -59,7 +59,6 @@ parse_bare_cr = {$double_quotes ->
 
 parse_bare_cr_in_raw_string = bare CR not allowed in raw string
 
-parse_binary_float_literal_not_supported = binary float literal is not supported
 parse_bounds_not_allowed_on_trait_aliases = bounds are not allowed on trait aliases
 
 parse_box_not_pat = expected pattern, found {$descr}
@@ -284,7 +283,6 @@ parse_generics_in_path = unexpected generic arguments in path
 
 parse_help_set_edition_cargo = set `edition = "{$edition}"` in `Cargo.toml`
 parse_help_set_edition_standalone = pass `--edition {$edition}` to `rustc`
-parse_hexadecimal_float_literal_not_supported = hexadecimal float literal is not supported
 parse_if_expression_missing_condition = missing condition for `if` expression
     .condition_label = expected condition here
     .block_label = if this block is the condition of the `if` expression, then it must be followed by another block
@@ -356,8 +354,6 @@ parse_inner_doc_comment_not_permitted = expected outer doc comment
     .label_does_not_annotate_this = the inner doc comment doesn't annotate this {$item}
     .sugg_change_inner_to_outer = to annotate the {$item}, change the doc comment from inner to outer style
 
-parse_int_literal_too_large = integer literal is too large
-
 parse_invalid_block_macro_segment = cannot use a `block` macro fragment here
     .label = the `block` fragment is within this context
     .suggestion = wrap this in another block
@@ -382,18 +378,8 @@ parse_invalid_dyn_keyword = invalid `dyn` keyword
     .suggestion = remove this keyword
 
 parse_invalid_expression_in_let_else = a `{$operator}` expression cannot be directly assigned in `let...else`
-parse_invalid_float_literal_suffix = invalid suffix `{$suffix}` for float literal
-    .label = invalid suffix `{$suffix}`
-    .help = valid suffixes are `f32` and `f64`
-
-parse_invalid_float_literal_width = invalid width `{$width}` for float literal
-    .help = valid widths are 32 and 64
-
 parse_invalid_identifier_with_leading_number = identifiers cannot start with a number
 
-parse_invalid_int_literal_width = invalid width `{$width}` for integer literal
-    .help = valid widths are 8, 16, 32, 64 and 128
-
 parse_invalid_interpolated_expression = invalid interpolated expression
 
 parse_invalid_literal_suffix = suffixes on {$kind} literals are invalid
@@ -412,14 +398,6 @@ parse_invalid_logical_operator = `{$incorrect}` is not a logical operator
 
 parse_invalid_meta_item = expected unsuffixed literal or identifier, found `{$token}`
 
-parse_invalid_num_literal_base_prefix = invalid base prefix for number literal
-    .note = base prefixes (`0xff`, `0b1010`, `0o755`) are lowercase
-    .suggestion = try making the prefix lowercase
-
-parse_invalid_num_literal_suffix = invalid suffix `{$suffix}` for number literal
-    .label = invalid suffix `{$suffix}`
-    .help = the suffix must be one of the numeric types (`u32`, `isize`, `f32`, etc.)
-
 parse_invalid_unicode_escape = invalid unicode character escape
     .label = invalid escape
     .help = unicode escape must {$surrogate ->
@@ -603,13 +581,6 @@ parse_no_brace_unicode_escape = incorrect unicode escape sequence
 
 parse_no_digits_literal = no valid digits found for number
 
-parse_non_item_in_item_list = non-item in item list
-    .suggestion_use_const_not_let = consider using `const` instead of `let` for associated const
-    .label_list_start = item list starts here
-    .label_non_item = non-item starts here
-    .label_list_end = item list ends here
-    .suggestion_remove_semicolon = consider removing this semicolon
-
 parse_non_string_abi_literal = non-string ABI literal
     .suggestion = specify the ABI with a string literal
 
@@ -626,7 +597,6 @@ parse_note_mut_pattern_usage = `mut` may be followed by `variable` and `variable
 
 parse_note_pattern_alternatives_use_single_vert = alternatives in or-patterns are separated with `|`, not `||`
 
-parse_octal_float_literal_not_supported = octal float literal is not supported
 parse_or_pattern_not_allowed_in_fn_parameters = top-level or-patterns are not allowed in function parameters
 parse_or_pattern_not_allowed_in_let_binding = top-level or-patterns are not allowed in `let` bindings
 parse_out_of_range_hex_escape = out of range hex escape

compiler/rustc_query_system/messages.ftl

@@ -15,8 +15,6 @@ query_system_cycle_stack_single = ...which immediately requires {$stack_bottom}
 
 query_system_cycle_usage = cycle used when {$usage}
 
-query_system_cycle_which_requires = ...which requires {$desc}...
-
 query_system_increment_compilation = internal compiler error: encountered incremental compilation error with {$dep_node}
     .help = This is a known issue with the compiler. Run {$run_cmd} to allow your project to compile
 

compiler/rustc_resolve/messages.ftl

@@ -130,9 +130,6 @@ resolve_generic_params_from_outer_item_ty_param = type parameter from outer item
 resolve_glob_import_doesnt_reexport =
     glob import doesn't reexport anything because no candidate is public enough
 
-resolve_help_try_using_local_generic_param =
-    try using a local generic parameter instead
-
 resolve_ident_bound_more_than_once_in_parameter_list =
     identifier `{$identifier}` is bound more than once in this parameter list
     .label = used as parameter more than once
@@ -249,9 +246,6 @@ resolve_self_in_generic_param_default =
     generic parameters cannot use `Self` in their defaults
     .label = `Self` in generic parameter default
 
-resolve_self_type_implicitly_declared_by_impl =
-    `Self` type implicitly declared here, by this `impl`
-
 resolve_tool_module_imported =
     cannot use a tool module through an import
     .note = the tool module imported here
@@ -267,12 +261,6 @@ resolve_trait_impl_mismatch =
     .label = does not match trait
     .label_trait_item = item in trait
 
-resolve_try_adding_local_generic_param_on_method =
-    try adding a local generic parameter in this method instead
-
-resolve_try_using_local_generic_parameter =
-    try using a local generic parameter instead
-
 resolve_try_using_similarly_named_label =
     try using similarly named label
 

compiler/rustc_session/messages.ftl

@@ -25,8 +25,6 @@ session_feature_diagnostic_for_issue =
 session_feature_diagnostic_help =
     add `#![feature({$feature})]` to the crate attributes to enable
 
-session_feature_gate_error = {$explain}
-
 session_file_is_not_writeable = output file {$file} is not writeable -- check its permissions
 
 session_file_write_fail = failed to write `{$path}` due to error `{$err}`

src/tools/tidy/src/fluent_alphabetical.rs renamed to src/tools/tidy/src/fluent_checks.rs

@@ -1,4 +1,5 @@
 //! Checks that all Flunt files have messages in alphabetical order
+//! Checks that all messages are referenced in the code
 
 use crate::walk::{filter_dirs, walk};
 use std::{fs::OpenOptions, io::Write, path::Path};
@@ -13,6 +14,10 @@ fn filter_fluent(path: &Path) -> bool {
     if let Some(ext) = path.extension() { ext.to_str() != Some("ftl") } else { true }
 }
 
+fn filter_not_rust(path: &Path) -> bool {
+    path.extension() != Some(std::ffi::OsStr::new("rs")) && !path.is_dir()
+}
+
 fn check_alphabetic(filename: &str, fluent: &str, bad: &mut bool) {
     let mut matches = MESSAGE.captures_iter(fluent).peekable();
     while let Some(m) = matches.next() {
@@ -34,16 +39,58 @@ run `./x.py test tidy --bless` to sort the file correctly",
     }
 }
 
-fn sort_messages(fluent: &str) -> String {
+fn check_unused_messages(
+    filename: &str,
+    fluent: &str,
+    bad: &mut bool,
+    report: bool,
+) -> Vec<String> {
+    let mut matches = MESSAGE.captures_iter(fluent).peekable();
+    let mut sources: Vec<String> = vec![];
+    if matches.peek().is_some() {
+        let src_dir = Path::new(filename).parent().unwrap().join("src");
+        walk(
+            &src_dir,
+            |path, is_dir| filter_dirs(path) || (!is_dir && filter_not_rust(path)),
+            &mut |_ent, contents| {
+                sources.push(contents.to_string());
+            },
+        );
+    }
+    let mut unused_messages = vec![];
+    while let Some(m) = matches.next() {
+        let name = m.get(1).unwrap();
+        // message maybe referenced as {name} in fluent files
+        let name_var = "{".to_string() + name.as_str() + "}";
+        if !sources.iter().any(|file| file.contains(name.as_str())) && !fluent.contains(&name_var) {
+            unused_messages.push(name.as_str().to_owned());
+            if report {
+                tidy_error!(
+                    bad,
+                    "{filename}: message `{}` is not referenced in the code",
+                    name.as_str()
+                );
+            }
+        }
+    }
+    unused_messages
+}
+
+fn sort_messages(filename: &str, fluent: &str) -> String {
     let mut chunks = vec![];
     let mut cur = String::new();
+    let unused_messages = check_unused_messages(filename, fluent, &mut false, false);
     for line in fluent.lines() {
         if MESSAGE.is_match(line) {
-            chunks.push(std::mem::take(&mut cur));
+            let chunk = std::mem::take(&mut cur);
+            if !unused_messages.iter().any(|key| chunk.starts_with(key)) {
+                chunks.push(chunk);
+            }
         }
         cur += line;
         cur.push('\n');
     }
+
     chunks.push(cur);
     chunks.sort();
     let mut out = chunks.join("");
@@ -57,15 +104,17 @@ pub fn check(path: &Path, bless: bool, bad: &mut bool) {
         path,
         |path, is_dir| filter_dirs(path) || (!is_dir && filter_fluent(path)),
         &mut |ent, contents| {
+            let filename = ent.path().to_str().unwrap();
             if bless {
-                let sorted = sort_messages(contents);
+                let sorted = sort_messages(filename, contents);
                 if sorted != contents {
                     let mut f =
                         OpenOptions::new().write(true).truncate(true).open(ent.path()).unwrap();
                     f.write(sorted.as_bytes()).unwrap();
                 }
             } else {
-                check_alphabetic(ent.path().to_str().unwrap(), contents, bad);
+                check_alphabetic(filename, contents, bad);
+                check_unused_messages(filename, contents, bad, true);
             }
         },
     );

src/tools/tidy/src/lib.rs

@@ -60,7 +60,7 @@ pub mod error_codes;
 pub mod ext_tool_checks;
 pub mod extdeps;
 pub mod features;
-pub mod fluent_alphabetical;
+pub mod fluent_checks;
 pub mod mir_opt_tests;
 pub mod pal;
 pub mod primitive_docs;

src/tools/tidy/src/main.rs

@@ -107,7 +107,7 @@ fn main() {
 
         // Checks that only make sense for the compiler.
         check!(error_codes, &root_path, &[&compiler_path, &librustdoc_path], verbose);
-        check!(fluent_alphabetical, &compiler_path, bless);
+        check!(fluent_checks, &compiler_path, bless);
 
         // Checks that only make sense for the std libs.
         check!(pal, &library_path);