diff options
| -rw-r--r-- | compiler/rustc_mir_transform/src/early_otherwise_branch.rs | 1 | ||||
| -rw-r--r-- | compiler/rustc_mir_transform/src/large_enums.rs | 3 | ||||
| -rw-r--r-- | compiler/rustc_mir_transform/src/nrvo.rs | 2 | ||||
| -rw-r--r-- | compiler/rustc_session/src/options.rs | 7 |
4 files changed, 9 insertions, 4 deletions
diff --git a/compiler/rustc_mir_transform/src/early_otherwise_branch.rs b/compiler/rustc_mir_transform/src/early_otherwise_branch.rs index 319fb4eaf3e..6eb6cb069fe 100644 --- a/compiler/rustc_mir_transform/src/early_otherwise_branch.rs +++ b/compiler/rustc_mir_transform/src/early_otherwise_branch.rs @@ -95,6 +95,7 @@ pub struct EarlyOtherwiseBranch; impl<'tcx> MirPass<'tcx> for EarlyOtherwiseBranch { fn is_enabled(&self, sess: &rustc_session::Session) -> bool { + // unsound: https://github.com/rust-lang/rust/issues/95162 sess.mir_opt_level() >= 3 && sess.opts.unstable_opts.unsound_mir_opts } diff --git a/compiler/rustc_mir_transform/src/large_enums.rs b/compiler/rustc_mir_transform/src/large_enums.rs index 886ff760481..0a8b13d6677 100644 --- a/compiler/rustc_mir_transform/src/large_enums.rs +++ b/compiler/rustc_mir_transform/src/large_enums.rs @@ -30,6 +30,9 @@ pub struct EnumSizeOpt { impl<'tcx> MirPass<'tcx> for EnumSizeOpt { fn is_enabled(&self, sess: &Session) -> bool { + // There are some differences in behavior on wasm and ARM that are not properly + // understood, so we conservatively treat this optimization as unsound: + // https://github.com/rust-lang/rust/pull/85158#issuecomment-1101836457 sess.opts.unstable_opts.unsound_mir_opts || sess.mir_opt_level() >= 3 } fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { diff --git a/compiler/rustc_mir_transform/src/nrvo.rs b/compiler/rustc_mir_transform/src/nrvo.rs index e1298b0654f..ff309bd10ec 100644 --- a/compiler/rustc_mir_transform/src/nrvo.rs +++ b/compiler/rustc_mir_transform/src/nrvo.rs @@ -34,7 +34,7 @@ pub struct RenameReturnPlace; impl<'tcx> MirPass<'tcx> for RenameReturnPlace { fn is_enabled(&self, sess: &rustc_session::Session) -> bool { - // #111005 + // unsound: #111005 sess.mir_opt_level() > 0 && sess.opts.unstable_opts.unsound_mir_opts } diff --git a/compiler/rustc_session/src/options.rs b/compiler/rustc_session/src/options.rs index f7c000c8bd6..5c020ed757a 100644 --- a/compiler/rustc_session/src/options.rs +++ b/compiler/rustc_session/src/options.rs @@ -1599,9 +1599,10 @@ options! { "emit Retagging MIR statements, interpreted e.g., by miri; implies -Zmir-opt-level=0 \ (default: no)"), mir_enable_passes: Vec<(String, bool)> = (Vec::new(), parse_list_with_polarity, [TRACKED], - "use like `-Zmir-enable-passes=+DestinationPropagation,-InstSimplify`. Forces the specified passes to be \ - enabled, overriding all other checks. Passes that are not specified are enabled or \ - disabled by other flags as usual."), + "use like `-Zmir-enable-passes=+DestinationPropagation,-InstSimplify`. Forces the \ + specified passes to be enabled, overriding all other checks. In particular, this will \ + enable unsound (known-buggy and hence usually disabled) passes without further warning! \ + Passes that are not specified are enabled or disabled by other flags as usual."), mir_include_spans: bool = (false, parse_bool, [UNTRACKED], "use line numbers relative to the function in mir pretty printing"), mir_keep_place_mention: bool = (false, parse_bool, [TRACKED], |