71a6c7c803
Display an extra note for trailing semicolon lint with trailing macro Currently, we parse macros at the end of a block (e.g. `fn foo() { my_macro!() }`) as expressions, rather than statements. This means that a macro invoked in this position cannot expand to items or semicolon-terminated expressions. In the future, we might want to start parsing these kinds of macros as statements. This would make expansion more 'token-based' (i.e. macro expansion behaves (almost) as if you just textually replaced the macro invocation with its output). However, this is a breaking change (see PR #78991), so it will require further discussion. Since the current behavior will not be changing any time soon, we need to address the interaction with the `SEMICOLON_IN_EXPRESSIONS_FROM_MACROS` lint. Since we are parsing the result of macro expansion as an expression, we will emit a lint if there's a trailing semicolon in the macro output. However, this results in a somewhat confusing message for users, since it visually looks like there should be no problem with having a semicolon at the end of a block (e.g. `fn foo() { my_macro!() }` => `fn foo() { produced_expr; }`) To help reduce confusion, this commit adds a note explaining that the macro is being interpreted as an expression. Additionally, we suggest adding a semicolon after the macro *invocation* - this will cause us to parse the macro call as a statement. We do *not* use a structured suggestion for this, since the user may actually want to remove the semicolon from the macro definition (allowing the block to evaluate to the expression produced by the macro). |
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rustc | ||
rustc_apfloat | ||
rustc_arena | ||
rustc_ast | ||
rustc_ast_lowering | ||
rustc_ast_passes | ||
rustc_ast_pretty | ||
rustc_attr | ||
rustc_builtin_macros | ||
rustc_codegen_cranelift | ||
rustc_codegen_llvm | ||
rustc_codegen_ssa | ||
rustc_data_structures | ||
rustc_driver | ||
rustc_error_codes | ||
rustc_errors | ||
rustc_expand | ||
rustc_feature | ||
rustc_fs_util | ||
rustc_graphviz | ||
rustc_hir | ||
rustc_hir_pretty | ||
rustc_incremental | ||
rustc_index | ||
rustc_infer | ||
rustc_interface | ||
rustc_lexer | ||
rustc_lint | ||
rustc_lint_defs | ||
rustc_llvm | ||
rustc_macros | ||
rustc_metadata | ||
rustc_middle | ||
rustc_mir | ||
rustc_mir_build | ||
rustc_parse | ||
rustc_parse_format | ||
rustc_passes | ||
rustc_plugin_impl | ||
rustc_privacy | ||
rustc_query_impl | ||
rustc_query_system | ||
rustc_resolve | ||
rustc_save_analysis | ||
rustc_serialize | ||
rustc_session | ||
rustc_span | ||
rustc_symbol_mangling | ||
rustc_target | ||
rustc_trait_selection | ||
rustc_traits | ||
rustc_ty_utils | ||
rustc_type_ir | ||
rustc_typeck |