gccrs: add unreachable pattern lint#4624
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CohenArthur
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| || (type == HIR::Pattern::PatternType::IDENTIFIER | ||
| && !static_cast<HIR::IdentifierPattern &> ( | ||
| *arm.get_pattern ()) | ||
| .has_subpattern ()))) |
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This also needs a test, not just the wildcard pattern. I think this is not enough to check that an identifier pattern is irrefutable, because for example this gets parsed as an identifier pattern:
enum Option<T> {
Some(T),
None,
}
use Option::{Some, None};
match some_option {
None => {},
}and is not irrefutable
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gcc/rust/ChangeLog: * checks/lints/unused/rust-unused-checker.cc (UnusedChecker::visit): New. * rust-lang.cc (grs_langhook_init_options_struct): Enable warn_unused. gcc/testsuite/ChangeLog: * rust/compile/unreachable-patterns_0.rs: New test. Signed-off-by: Lucas Ly Ba <lucas.ly-ba@outlook.com>
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This patch adds the unreachable pattern lint, which warns on match arms that can never be reached because an earlier arm is irrefutable.
gcc/testsuite/ChangeLog: