diff options
Diffstat (limited to 'compiler/rustc_mir_transform')
11 files changed, 82 insertions, 39 deletions
diff --git a/compiler/rustc_mir_transform/src/coroutine.rs b/compiler/rustc_mir_transform/src/coroutine.rs index 9d44001f915..fa5da89e8ba 100644 --- a/compiler/rustc_mir_transform/src/coroutine.rs +++ b/compiler/rustc_mir_transform/src/coroutine.rs @@ -1367,6 +1367,10 @@ fn can_unwind<'tcx>(tcx: TyCtxt<'tcx>, body: &Body<'tcx>) -> bool { | TerminatorKind::Call { .. } | TerminatorKind::InlineAsm { .. } | TerminatorKind::Assert { .. } => return true, + + TerminatorKind::TailCall { .. } => { + unreachable!("tail calls can't be present in generators") + } } } @@ -1916,6 +1920,7 @@ impl<'tcx> Visitor<'tcx> for EnsureCoroutineFieldAssignmentsNeverAlias<'_> { | TerminatorKind::UnwindResume | TerminatorKind::UnwindTerminate(_) | TerminatorKind::Return + | TerminatorKind::TailCall { .. } | TerminatorKind::Unreachable | TerminatorKind::Drop { .. } | TerminatorKind::Assert { .. } diff --git a/compiler/rustc_mir_transform/src/cost_checker.rs b/compiler/rustc_mir_transform/src/cost_checker.rs index 3333bebff3a..a1c1422912e 100644 --- a/compiler/rustc_mir_transform/src/cost_checker.rs +++ b/compiler/rustc_mir_transform/src/cost_checker.rs @@ -40,7 +40,9 @@ impl<'b, 'tcx> CostChecker<'b, 'tcx> { fn is_call_like(bbd: &BasicBlockData<'_>) -> bool { use TerminatorKind::*; match bbd.terminator().kind { - Call { .. } | Drop { .. } | Assert { .. } | InlineAsm { .. } => true, + Call { .. } | TailCall { .. } | Drop { .. } | Assert { .. } | InlineAsm { .. } => { + true + } Goto { .. } | SwitchInt { .. } @@ -137,6 +139,9 @@ impl<'tcx> Visitor<'tcx> for CostChecker<'_, 'tcx> { self.penalty += LANDINGPAD_PENALTY; } } + TerminatorKind::TailCall { .. } => { + self.penalty += CALL_PENALTY; + } TerminatorKind::SwitchInt { discr, targets } => { if discr.constant().is_some() { // Not only will this become a `Goto`, but likely other diff --git a/compiler/rustc_mir_transform/src/coverage/graph.rs b/compiler/rustc_mir_transform/src/coverage/graph.rs index 360dccb240d..83fb9ff9743 100644 --- a/compiler/rustc_mir_transform/src/coverage/graph.rs +++ b/compiler/rustc_mir_transform/src/coverage/graph.rs @@ -358,9 +358,12 @@ fn bcb_filtered_successors<'a, 'tcx>(terminator: &'a Terminator<'tcx>) -> Covera } // These terminators have no coverage-relevant successors. - CoroutineDrop | Return | Unreachable | UnwindResume | UnwindTerminate(_) => { - CoverageSuccessors::NotChainable(&[]) - } + CoroutineDrop + | Return + | TailCall { .. } + | Unreachable + | UnwindResume + | UnwindTerminate(_) => CoverageSuccessors::NotChainable(&[]), } } diff --git a/compiler/rustc_mir_transform/src/coverage/spans/from_mir.rs b/compiler/rustc_mir_transform/src/coverage/spans/from_mir.rs index 2ca166929ee..a0f8f580b1d 100644 --- a/compiler/rustc_mir_transform/src/coverage/spans/from_mir.rs +++ b/compiler/rustc_mir_transform/src/coverage/spans/from_mir.rs @@ -193,7 +193,8 @@ fn filtered_terminator_span(terminator: &Terminator<'_>) -> Option<Span> { | TerminatorKind::Goto { .. } => None, // Call `func` operand can have a more specific span when part of a chain of calls - | TerminatorKind::Call { ref func, .. } => { + TerminatorKind::Call { ref func, .. } + | TerminatorKind::TailCall { ref func, .. } => { let mut span = terminator.source_info.span; if let mir::Operand::Constant(box constant) = func { if constant.span.lo() > span.lo() { diff --git a/compiler/rustc_mir_transform/src/dest_prop.rs b/compiler/rustc_mir_transform/src/dest_prop.rs index b1016c0867c..ab73a8af317 100644 --- a/compiler/rustc_mir_transform/src/dest_prop.rs +++ b/compiler/rustc_mir_transform/src/dest_prop.rs @@ -628,6 +628,12 @@ impl WriteInfo { self.add_operand(&arg.node); } } + TerminatorKind::TailCall { func, args, .. } => { + self.add_operand(func); + for arg in args { + self.add_operand(&arg.node); + } + } TerminatorKind::InlineAsm { operands, .. } => { for asm_operand in operands { match asm_operand { diff --git a/compiler/rustc_mir_transform/src/inline.rs b/compiler/rustc_mir_transform/src/inline.rs index 5075e072754..fe73715480f 100644 --- a/compiler/rustc_mir_transform/src/inline.rs +++ b/compiler/rustc_mir_transform/src/inline.rs @@ -383,6 +383,8 @@ impl<'tcx> Inliner<'tcx> { ) -> Option<CallSite<'tcx>> { // Only consider direct calls to functions let terminator = bb_data.terminator(); + + // FIXME(explicit_tail_calls): figure out if we can inline tail calls if let TerminatorKind::Call { ref func, fn_span, .. } = terminator.kind { let func_ty = func.ty(caller_body, self.tcx); if let ty::FnDef(def_id, args) = *func_ty.kind() { @@ -550,6 +552,9 @@ impl<'tcx> Inliner<'tcx> { // inline-asm is detected. LLVM will still possibly do an inline later on // if the no-attribute function ends up with the same instruction set anyway. return Err("Cannot move inline-asm across instruction sets"); + } else if let TerminatorKind::TailCall { .. } = term.kind { + // FIXME(explicit_tail_calls): figure out how exactly functions containing tail calls can be inlined (and if they even should) + return Err("can't inline functions with tail calls"); } else { work_list.extend(term.successors()) } @@ -1038,6 +1043,10 @@ impl<'tcx> MutVisitor<'tcx> for Integrator<'_, 'tcx> { *target = self.map_block(*target); *unwind = self.map_unwind(*unwind); } + TerminatorKind::TailCall { .. } => { + // check_mir_body forbids tail calls + unreachable!() + } TerminatorKind::Call { ref mut target, ref mut unwind, .. } => { if let Some(ref mut tgt) = *target { *tgt = self.map_block(*tgt); diff --git a/compiler/rustc_mir_transform/src/jump_threading.rs b/compiler/rustc_mir_transform/src/jump_threading.rs index 85a61f95ca3..97ec0cb39de 100644 --- a/compiler/rustc_mir_transform/src/jump_threading.rs +++ b/compiler/rustc_mir_transform/src/jump_threading.rs @@ -596,6 +596,7 @@ impl<'tcx, 'a> TOFinder<'tcx, 'a> { TerminatorKind::UnwindResume | TerminatorKind::UnwindTerminate(_) | TerminatorKind::Return + | TerminatorKind::TailCall { .. } | TerminatorKind::Unreachable | TerminatorKind::CoroutineDrop => bug!("{term:?} has no terminators"), // Disallowed during optimizations. diff --git a/compiler/rustc_mir_transform/src/known_panics_lint.rs b/compiler/rustc_mir_transform/src/known_panics_lint.rs index 8d6c00bbedb..82ad8879d17 100644 --- a/compiler/rustc_mir_transform/src/known_panics_lint.rs +++ b/compiler/rustc_mir_transform/src/known_panics_lint.rs @@ -799,6 +799,7 @@ impl<'tcx> Visitor<'tcx> for ConstPropagator<'_, 'tcx> { | TerminatorKind::UnwindResume | TerminatorKind::UnwindTerminate(_) | TerminatorKind::Return + | TerminatorKind::TailCall { .. } | TerminatorKind::Unreachable | TerminatorKind::Drop { .. } | TerminatorKind::Yield { .. } diff --git a/compiler/rustc_mir_transform/src/mentioned_items.rs b/compiler/rustc_mir_transform/src/mentioned_items.rs index db2bb60bdac..d928d7cf764 100644 --- a/compiler/rustc_mir_transform/src/mentioned_items.rs +++ b/compiler/rustc_mir_transform/src/mentioned_items.rs @@ -38,7 +38,7 @@ impl<'tcx> Visitor<'tcx> for MentionedItemsVisitor<'_, 'tcx> { self.super_terminator(terminator, location); let span = || self.body.source_info(location).span; match &terminator.kind { - mir::TerminatorKind::Call { func, .. } => { + mir::TerminatorKind::Call { func, .. } | mir::TerminatorKind::TailCall { func, .. } => { let callee_ty = func.ty(self.body, self.tcx); self.mentioned_items .push(Spanned { node: MentionedItem::Fn(callee_ty), span: span() }); diff --git a/compiler/rustc_mir_transform/src/remove_noop_landing_pads.rs b/compiler/rustc_mir_transform/src/remove_noop_landing_pads.rs index fb52bfa468a..1df5737e859 100644 --- a/compiler/rustc_mir_transform/src/remove_noop_landing_pads.rs +++ b/compiler/rustc_mir_transform/src/remove_noop_landing_pads.rs @@ -75,6 +75,7 @@ impl RemoveNoopLandingPads { | TerminatorKind::UnwindTerminate(_) | TerminatorKind::Unreachable | TerminatorKind::Call { .. } + | TerminatorKind::TailCall { .. } | TerminatorKind::Assert { .. } | TerminatorKind::Drop { .. } | TerminatorKind::InlineAsm { .. } => false, diff --git a/compiler/rustc_mir_transform/src/validate.rs b/compiler/rustc_mir_transform/src/validate.rs index 2018a8fe667..ab5c25c4937 100644 --- a/compiler/rustc_mir_transform/src/validate.rs +++ b/compiler/rustc_mir_transform/src/validate.rs @@ -400,40 +400,44 @@ impl<'a, 'tcx> Visitor<'tcx> for CfgChecker<'a, 'tcx> { self.check_edge(location, *target, EdgeKind::Normal); self.check_unwind_edge(location, *unwind); } - TerminatorKind::Call { args, destination, target, unwind, .. } => { - if let Some(target) = target { - self.check_edge(location, *target, EdgeKind::Normal); - } - self.check_unwind_edge(location, *unwind); + TerminatorKind::Call { args, .. } | TerminatorKind::TailCall { args, .. } => { + // FIXME(explicit_tail_calls): refactor this & add tail-call specific checks + if let TerminatorKind::Call { target, unwind, destination, .. } = terminator.kind { + if let Some(target) = target { + self.check_edge(location, target, EdgeKind::Normal); + } + self.check_unwind_edge(location, unwind); + + // The code generation assumes that there are no critical call edges. The assumption + // is used to simplify inserting code that should be executed along the return edge + // from the call. FIXME(tmiasko): Since this is a strictly code generation concern, + // the code generation should be responsible for handling it. + if self.mir_phase >= MirPhase::Runtime(RuntimePhase::Optimized) + && self.is_critical_call_edge(target, unwind) + { + self.fail( + location, + format!( + "encountered critical edge in `Call` terminator {:?}", + terminator.kind, + ), + ); + } - // The code generation assumes that there are no critical call edges. The assumption - // is used to simplify inserting code that should be executed along the return edge - // from the call. FIXME(tmiasko): Since this is a strictly code generation concern, - // the code generation should be responsible for handling it. - if self.mir_phase >= MirPhase::Runtime(RuntimePhase::Optimized) - && self.is_critical_call_edge(*target, *unwind) - { - self.fail( - location, - format!( - "encountered critical edge in `Call` terminator {:?}", - terminator.kind, - ), - ); + // The call destination place and Operand::Move place used as an argument might be + // passed by a reference to the callee. Consequently they cannot be packed. + if is_within_packed(self.tcx, &self.body.local_decls, destination).is_some() { + // This is bad! The callee will expect the memory to be aligned. + self.fail( + location, + format!( + "encountered packed place in `Call` terminator destination: {:?}", + terminator.kind, + ), + ); + } } - // The call destination place and Operand::Move place used as an argument might be - // passed by a reference to the callee. Consequently they cannot be packed. - if is_within_packed(self.tcx, &self.body.local_decls, *destination).is_some() { - // This is bad! The callee will expect the memory to be aligned. - self.fail( - location, - format!( - "encountered packed place in `Call` terminator destination: {:?}", - terminator.kind, - ), - ); - } for arg in args { if let Operand::Move(place) = &arg.node { if is_within_packed(self.tcx, &self.body.local_decls, *place).is_some() { @@ -1498,15 +1502,22 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> { } } } - TerminatorKind::Call { func, .. } => { + TerminatorKind::Call { func, .. } | TerminatorKind::TailCall { func, .. } => { let func_ty = func.ty(&self.body.local_decls, self.tcx); match func_ty.kind() { ty::FnPtr(..) | ty::FnDef(..) => {} _ => self.fail( location, - format!("encountered non-callable type {func_ty} in `Call` terminator"), + format!( + "encountered non-callable type {func_ty} in `{}` terminator", + terminator.kind.name() + ), ), } + + if let TerminatorKind::TailCall { .. } = terminator.kind { + // FIXME(explicit_tail_calls): implement tail-call specific checks here (such as signature matching, forbidding closures, etc) + } } TerminatorKind::Assert { cond, .. } => { let cond_ty = cond.ty(&self.body.local_decls, self.tcx); |