diff options
| -rw-r--r-- | src/librustc/session/config.rs | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/src/librustc/session/config.rs b/src/librustc/session/config.rs index 8e223170894..084a5429f26 100644 --- a/src/librustc/session/config.rs +++ b/src/librustc/session/config.rs @@ -2181,6 +2181,12 @@ pub fn build_session_options_and_crate_config( TargetTriple::from_triple(host_triple()) }; let opt_level = { + // The `-O` and `-C opt-level` flags specify the same setting, so we want to be able + // to use them interchangeably. However, because they're technically different flags, + // we need to work out manually which should take precedence if both are supplied (i.e. + // the rightmost flag). We do this by finding the (rightmost) position of both flags and + // comparing them. Note that if a flag is not found, its position will be `None`, which + // always compared less than `Some(_)`. let max_o = matches.opt_positions("O").into_iter().max(); let max_c = matches.opt_strs_pos("C").into_iter().flat_map(|(i, s)| { if let Some("opt-level") = s.splitn(2, '=').next() { @@ -2213,6 +2219,9 @@ pub fn build_session_options_and_crate_config( } } }; + // The `-g` and `-C debuginfo` flags specify the same setting, so we want to be able + // to use them interchangeably. See the note above (regarding `-O` and `-C opt-level`) + // for more details. let debug_assertions = cg.debug_assertions.unwrap_or(opt_level == OptLevel::No); let max_g = matches.opt_positions("g").into_iter().max(); let max_c = matches.opt_strs_pos("C").into_iter().flat_map(|(i, s)| { |