diff options
| -rw-r--r-- | compiler/rustc_codegen_ssa/src/mir/constant.rs | 2 | ||||
| -rw-r--r-- | compiler/rustc_codegen_ssa/src/mir/mod.rs | 4 | ||||
| -rw-r--r-- | compiler/rustc_middle/src/mir/visit.rs | 2 | ||||
| -rw-r--r-- | compiler/rustc_monomorphize/src/collector.rs | 2 |
4 files changed, 10 insertions, 0 deletions
diff --git a/compiler/rustc_codegen_ssa/src/mir/constant.rs b/compiler/rustc_codegen_ssa/src/mir/constant.rs index fde4e85f966..558f64fffc2 100644 --- a/compiler/rustc_codegen_ssa/src/mir/constant.rs +++ b/compiler/rustc_codegen_ssa/src/mir/constant.rs @@ -21,6 +21,8 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { } pub fn eval_mir_constant(&self, constant: &mir::ConstOperand<'tcx>) -> mir::ConstValue<'tcx> { + // `MirUsedCollector` visited all constants before codegen began, so if we got here there + // can be no more constants that fail to evaluate. self.monomorphize(constant.const_) .eval(self.cx.tcx(), ty::ParamEnv::reveal_all(), Some(constant.span)) .expect("erroneous constant not captured by required_consts") diff --git a/compiler/rustc_codegen_ssa/src/mir/mod.rs b/compiler/rustc_codegen_ssa/src/mir/mod.rs index 06cdc47610d..d0b799e087b 100644 --- a/compiler/rustc_codegen_ssa/src/mir/mod.rs +++ b/compiler/rustc_codegen_ssa/src/mir/mod.rs @@ -209,6 +209,10 @@ pub fn codegen_mir<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>( caller_location: None, }; + // It may seem like we should iterate over `required_consts` to ensure they all successfully + // evaluate; however, the `MirUsedCollector` already did that during the collection phase of + // monomorphization so we don't have to do it again. + fx.per_local_var_debug_info = fx.compute_per_local_var_debug_info(&mut start_bx); let memory_locals = analyze::non_ssa_locals(&fx); diff --git a/compiler/rustc_middle/src/mir/visit.rs b/compiler/rustc_middle/src/mir/visit.rs index 51ec6da1ac8..cc135f732cb 100644 --- a/compiler/rustc_middle/src/mir/visit.rs +++ b/compiler/rustc_middle/src/mir/visit.rs @@ -184,6 +184,8 @@ macro_rules! make_mir_visitor { visit_place_fns!($($mutability)?); + /// This is called for every constant in the MIR body and every `required_consts` + /// (i.e., including consts that have been dead-code-eliminated). fn visit_constant( &mut self, constant: & $($mutability)? ConstOperand<'tcx>, diff --git a/compiler/rustc_monomorphize/src/collector.rs b/compiler/rustc_monomorphize/src/collector.rs index 1a9f0e8352e..8525a4e74c2 100644 --- a/compiler/rustc_monomorphize/src/collector.rs +++ b/compiler/rustc_monomorphize/src/collector.rs @@ -1426,6 +1426,8 @@ fn collect_used_items<'tcx>( ); } + // Here we rely on the visitor also visiting `required_consts`, so that we evaluate them + // and abort compilation if any of them errors. MirUsedCollector { tcx, body: &body, |