Detect macros with duplicate metavariable bindings #4405
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This is imperfect, as invalid macro definitions should be detected regardless of whether a macro is used or not. gcc/rust/ChangeLog: * expand/rust-macro-expand.cc (MacroExpander::expand_decl_macro): Prevent excess errors. (MacroExpander::match_matcher): Detect duplicate metavariable names. * expand/rust-macro-expand.h (MacroExpander::MacroExpander): Initialize field had_duplicate_error. (MacroExpander::had_duplicate_error): New field. gcc/testsuite/ChangeLog: * rust/compile/macros/mbe/macro-duplicate-binding.rs: New test. Signed-off-by: Owen Avery <powerboat9.gamer@gmail.com>
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Jan 22, 2026
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This is imperfect, as invalid macro definitions should be detected regardless of whether a macro is used or not.