diff options
Diffstat (limited to 'compiler/rustc_codegen_ssa/src/mir/block.rs')
| -rw-r--r-- | compiler/rustc_codegen_ssa/src/mir/block.rs | 356 |
1 files changed, 141 insertions, 215 deletions
diff --git a/compiler/rustc_codegen_ssa/src/mir/block.rs b/compiler/rustc_codegen_ssa/src/mir/block.rs index 57a19a4ab..dd8697781 100644 --- a/compiler/rustc_codegen_ssa/src/mir/block.rs +++ b/compiler/rustc_codegen_ssa/src/mir/block.rs @@ -16,7 +16,7 @@ use rustc_index::vec::Idx; use rustc_middle::mir::{self, AssertKind, SwitchTargets}; use rustc_middle::ty::layout::{HasTyCtxt, LayoutOf, ValidityRequirement}; use rustc_middle::ty::print::{with_no_trimmed_paths, with_no_visible_paths}; -use rustc_middle::ty::{self, Instance, Ty, TypeVisitableExt}; +use rustc_middle::ty::{self, Instance, Ty}; use rustc_session::config::OptLevel; use rustc_span::source_map::Span; use rustc_span::{sym, Symbol}; @@ -147,7 +147,7 @@ impl<'a, 'tcx> TerminatorCodegenHelper<'tcx> { } /// Call `fn_ptr` of `fn_abi` with the arguments `llargs`, the optional - /// return destination `destination` and the cleanup function `cleanup`. + /// return destination `destination` and the unwind action `unwind`. fn do_call<Bx: BuilderMethods<'a, 'tcx>>( &self, fx: &mut FunctionCx<'a, 'tcx, Bx>, @@ -156,7 +156,7 @@ impl<'a, 'tcx> TerminatorCodegenHelper<'tcx> { fn_ptr: Bx::Value, llargs: &[Bx::Value], destination: Option<(ReturnDest<'tcx, Bx::Value>, mir::BasicBlock)>, - cleanup: Option<mir::BasicBlock>, + mut unwind: mir::UnwindAction, copied_constant_arguments: &[PlaceRef<'tcx, <Bx as BackendTypes>::Value>], mergeable_succ: bool, ) -> MergingSucc { @@ -164,23 +164,23 @@ impl<'a, 'tcx> TerminatorCodegenHelper<'tcx> { // do an invoke, otherwise do a call. let fn_ty = bx.fn_decl_backend_type(&fn_abi); - let unwind_block = if let Some(cleanup) = cleanup.filter(|_| fn_abi.can_unwind) { - Some(self.llbb_with_cleanup(fx, cleanup)) - } else if fx.mir[self.bb].is_cleanup - && fn_abi.can_unwind - && !base::wants_msvc_seh(fx.cx.tcx().sess) - { - // Exception must not propagate out of the execution of a cleanup (doing so - // can cause undefined behaviour). We insert a double unwind guard for - // functions that can potentially unwind to protect against this. - // - // This is not necessary for SEH which does not use successive unwinding - // like Itanium EH. EH frames in SEH are different from normal function - // frames and SEH will abort automatically if an exception tries to - // propagate out from cleanup. - Some(fx.double_unwind_guard()) - } else { - None + if !fn_abi.can_unwind { + unwind = mir::UnwindAction::Unreachable; + } + + let unwind_block = match unwind { + mir::UnwindAction::Cleanup(cleanup) => Some(self.llbb_with_cleanup(fx, cleanup)), + mir::UnwindAction::Continue => None, + mir::UnwindAction::Unreachable => None, + mir::UnwindAction::Terminate => { + if fx.mir[self.bb].is_cleanup && base::wants_msvc_seh(fx.cx.tcx().sess) { + // SEH will abort automatically if an exception tries to + // propagate out from cleanup. + None + } else { + Some(fx.terminate_block()) + } + } }; if let Some(unwind_block) = unwind_block { @@ -234,7 +234,7 @@ impl<'a, 'tcx> TerminatorCodegenHelper<'tcx> { } } - /// Generates inline assembly with optional `destination` and `cleanup`. + /// Generates inline assembly with optional `destination` and `unwind`. fn do_inlineasm<Bx: BuilderMethods<'a, 'tcx>>( &self, fx: &mut FunctionCx<'a, 'tcx, Bx>, @@ -244,11 +244,18 @@ impl<'a, 'tcx> TerminatorCodegenHelper<'tcx> { options: InlineAsmOptions, line_spans: &[Span], destination: Option<mir::BasicBlock>, - cleanup: Option<mir::BasicBlock>, + unwind: mir::UnwindAction, instance: Instance<'_>, mergeable_succ: bool, ) -> MergingSucc { - if let Some(cleanup) = cleanup { + let unwind_target = match unwind { + mir::UnwindAction::Cleanup(cleanup) => Some(self.llbb_with_cleanup(fx, cleanup)), + mir::UnwindAction::Terminate => Some(fx.terminate_block()), + mir::UnwindAction::Continue => None, + mir::UnwindAction::Unreachable => None, + }; + + if let Some(cleanup) = unwind_target { let ret_llbb = if let Some(target) = destination { fx.llbb(target) } else { @@ -261,7 +268,7 @@ impl<'a, 'tcx> TerminatorCodegenHelper<'tcx> { options, line_spans, instance, - Some((ret_llbb, self.llbb_with_cleanup(fx, cleanup), self.funclet(fx))), + Some((ret_llbb, cleanup, self.funclet(fx))), ); MergingSucc::False } else { @@ -397,8 +404,8 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { PassMode::Cast(cast_ty, _) => { let op = match self.locals[mir::RETURN_PLACE] { - LocalRef::Operand(Some(op)) => op, - LocalRef::Operand(None) => bug!("use of return before def"), + LocalRef::Operand(op) => op, + LocalRef::PendingOperand => bug!("use of return before def"), LocalRef::Place(cg_place) => OperandRef { val: Ref(cg_place.llval, None, cg_place.align), layout: cg_place.layout, @@ -431,7 +438,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { bx: &mut Bx, location: mir::Place<'tcx>, target: mir::BasicBlock, - unwind: Option<mir::BasicBlock>, + unwind: mir::UnwindAction, mergeable_succ: bool, ) -> MergingSucc { let ty = location.ty(self.mir, bx.tcx()).ty; @@ -552,7 +559,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { expected: bool, msg: &mir::AssertMessage<'tcx>, target: mir::BasicBlock, - cleanup: Option<mir::BasicBlock>, + unwind: mir::UnwindAction, mergeable_succ: bool, ) -> MergingSucc { let span = terminator.source_info.span; @@ -563,15 +570,8 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { // with #[rustc_inherit_overflow_checks] and inlined from // another crate (mostly core::num generic/#[inline] fns), // while the current crate doesn't use overflow checks. - if !bx.cx().check_overflow() { - let overflow_not_to_check = match msg { - AssertKind::OverflowNeg(..) => true, - AssertKind::Overflow(op, ..) => op.is_checkable(), - _ => false, - }; - if overflow_not_to_check { - const_cond = Some(expected); - } + if !bx.cx().check_overflow() && msg.is_optional_overflow_check() { + const_cond = Some(expected); } // Don't codegen the panic block if success if known. @@ -607,6 +607,13 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { // and `#[track_caller]` adds an implicit third argument. (LangItem::PanicBoundsCheck, vec![index, len, location]) } + AssertKind::MisalignedPointerDereference { ref required, ref found } => { + let required = self.codegen_operand(bx, required).immediate(); + let found = self.codegen_operand(bx, found).immediate(); + // It's `fn panic_bounds_check(index: usize, len: usize)`, + // and `#[track_caller]` adds an implicit third argument. + (LangItem::PanicMisalignedPointerDereference, vec![required, found, location]) + } _ => { let msg = bx.const_str(msg.description()); // It's `pub fn panic(expr: &str)`, with the wide reference being passed @@ -618,12 +625,12 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { let (fn_abi, llfn) = common::build_langcall(bx, Some(span), lang_item); // Codegen the actual panic invoke/call. - let merging_succ = helper.do_call(self, bx, fn_abi, llfn, &args, None, cleanup, &[], false); + let merging_succ = helper.do_call(self, bx, fn_abi, llfn, &args, None, unwind, &[], false); assert_eq!(merging_succ, MergingSucc::False); MergingSucc::False } - fn codegen_abort_terminator( + fn codegen_terminate_terminator( &mut self, helper: TerminatorCodegenHelper<'tcx>, bx: &mut Bx, @@ -636,7 +643,17 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { let (fn_abi, llfn) = common::build_langcall(bx, Some(span), LangItem::PanicCannotUnwind); // Codegen the actual panic invoke/call. - let merging_succ = helper.do_call(self, bx, fn_abi, llfn, &[], None, None, &[], false); + let merging_succ = helper.do_call( + self, + bx, + fn_abi, + llfn, + &[], + None, + mir::UnwindAction::Unreachable, + &[], + false, + ); assert_eq!(merging_succ, MergingSucc::False); } @@ -649,7 +666,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { instance: Option<Instance<'tcx>>, source_info: mir::SourceInfo, target: Option<mir::BasicBlock>, - cleanup: Option<mir::BasicBlock>, + unwind: mir::UnwindAction, mergeable_succ: bool, ) -> Option<MergingSucc> { // Emit a panic or a no-op for `assert_*` intrinsics. @@ -696,7 +713,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { llfn, &[msg.0, msg.1], target.as_ref().map(|bb| (ReturnDest::Nothing, *bb)), - cleanup, + unwind, &[], mergeable_succ, ) @@ -719,7 +736,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { args: &[mir::Operand<'tcx>], destination: mir::Place<'tcx>, target: Option<mir::BasicBlock>, - cleanup: Option<mir::BasicBlock>, + unwind: mir::UnwindAction, fn_span: Span, mergeable_succ: bool, ) -> MergingSucc { @@ -776,23 +793,6 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { None => bx.fn_abi_of_fn_ptr(sig, extra_args), }; - if intrinsic == Some(sym::transmute) { - return if let Some(target) = target { - self.codegen_transmute(bx, &args[0], destination); - helper.funclet_br(self, bx, target, mergeable_succ) - } else { - // If we are trying to transmute to an uninhabited type, - // it is likely there is no allotted destination. In fact, - // transmuting to an uninhabited type is UB, which means - // we can do what we like. Here, we declare that transmuting - // into an uninhabited type is impossible, so anything following - // it must be unreachable. - assert_eq!(fn_abi.ret.layout.abi, abi::Abi::Uninhabited); - bx.unreachable(); - MergingSucc::False - }; - } - if let Some(merging_succ) = self.codegen_panic_intrinsic( &helper, bx, @@ -800,7 +800,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { instance, source_info, target, - cleanup, + unwind, mergeable_succ, ) { return merging_succ; @@ -835,7 +835,6 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { match intrinsic { None | Some(sym::drop_in_place) => {} - Some(sym::copy_nonoverlapping) => unreachable!(), Some(intrinsic) => { let dest = match ret_dest { _ if fn_abi.ret.is_indirect() => llargs[0], @@ -924,7 +923,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { // // This is also relevant for `Pin<&mut Self>`, where we need to peel the `Pin`. 'descend_newtypes: while !op.layout.ty.is_unsafe_ptr() - && !op.layout.ty.is_region_ptr() + && !op.layout.ty.is_ref() { for i in 0..op.layout.fields.count() { let field = op.extract_field(bx, i); @@ -966,7 +965,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { Immediate(_) => { // See comment above explaining why we peel these newtypes 'descend_newtypes: while !op.layout.ty.is_unsafe_ptr() - && !op.layout.ty.is_region_ptr() + && !op.layout.ty.is_ref() { for i in 0..op.layout.fields.count() { let field = op.extract_field(bx, i); @@ -1082,7 +1081,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { fn_ptr, &llargs, target.as_ref().map(|&target| (ret_dest, target)), - cleanup, + unwind, &copied_constant_arguments, false, ); @@ -1102,7 +1101,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { fn_ptr, &llargs, target.as_ref().map(|&target| (ret_dest, target)), - cleanup, + unwind, &copied_constant_arguments, mergeable_succ, ) @@ -1118,7 +1117,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { options: ast::InlineAsmOptions, line_spans: &[Span], destination: Option<mir::BasicBlock>, - cleanup: Option<mir::BasicBlock>, + unwind: mir::UnwindAction, instance: Instance<'_>, mergeable_succ: bool, ) -> MergingSucc { @@ -1182,7 +1181,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { options, line_spans, destination, - cleanup, + unwind, instance, mergeable_succ, ) @@ -1264,8 +1263,8 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { MergingSucc::False } - mir::TerminatorKind::Abort => { - self.codegen_abort_terminator(helper, bx, terminator); + mir::TerminatorKind::Terminate => { + self.codegen_terminate_terminator(helper, bx, terminator); MergingSucc::False } @@ -1292,7 +1291,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { self.codegen_drop_terminator(helper, bx, place, target, unwind, mergeable_succ()) } - mir::TerminatorKind::Assert { ref cond, expected, ref msg, target, cleanup } => self + mir::TerminatorKind::Assert { ref cond, expected, ref msg, target, unwind } => self .codegen_assert_terminator( helper, bx, @@ -1301,20 +1300,16 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { expected, msg, target, - cleanup, + unwind, mergeable_succ(), ), - mir::TerminatorKind::DropAndReplace { .. } => { - bug!("undesugared DropAndReplace in codegen: {:?}", terminator); - } - mir::TerminatorKind::Call { ref func, ref args, destination, target, - cleanup, + unwind, from_hir_call: _, fn_span, } => self.codegen_call_terminator( @@ -1325,7 +1320,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { args, destination, target, - cleanup, + unwind, fn_span, mergeable_succ(), ), @@ -1342,7 +1337,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { options, line_spans, destination, - cleanup, + unwind, } => self.codegen_asm_terminator( helper, bx, @@ -1352,7 +1347,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { options, line_spans, destination, - cleanup, + unwind, self.instance, mergeable_succ(), ), @@ -1486,7 +1481,11 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { ) -> OperandRef<'tcx, Bx::Value> { let tcx = bx.tcx(); - let mut span_to_caller_location = |span: Span| { + let mut span_to_caller_location = |mut span: Span| { + // Remove `Inlined` marks as they pollute `expansion_cause`. + while span.is_inlined() { + span.remove_mark(); + } let topmost = span.ctxt().outer_expn().expansion_cause().unwrap_or(span); let caller = tcx.sess.source_map().lookup_char_pos(topmost.lo()); let const_loc = tcx.const_caller_location(( @@ -1554,62 +1553,12 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { fn landing_pad_for_uncached(&mut self, bb: mir::BasicBlock) -> Bx::BasicBlock { let llbb = self.llbb(bb); if base::wants_msvc_seh(self.cx.sess()) { - let funclet; - let ret_llbb; - match self.mir[bb].terminator.as_ref().map(|t| &t.kind) { - // This is a basic block that we're aborting the program for, - // notably in an `extern` function. These basic blocks are inserted - // so that we assert that `extern` functions do indeed not panic, - // and if they do we abort the process. - // - // On MSVC these are tricky though (where we're doing funclets). If - // we were to do a cleanuppad (like below) the normal functions like - // `longjmp` would trigger the abort logic, terminating the - // program. Instead we insert the equivalent of `catch(...)` for C++ - // which magically doesn't trigger when `longjmp` files over this - // frame. - // - // Lots more discussion can be found on #48251 but this codegen is - // modeled after clang's for: - // - // try { - // foo(); - // } catch (...) { - // bar(); - // } - Some(&mir::TerminatorKind::Abort) => { - let cs_llbb = - Bx::append_block(self.cx, self.llfn, &format!("cs_funclet{:?}", bb)); - let cp_llbb = - Bx::append_block(self.cx, self.llfn, &format!("cp_funclet{:?}", bb)); - ret_llbb = cs_llbb; - - let mut cs_bx = Bx::build(self.cx, cs_llbb); - let cs = cs_bx.catch_switch(None, None, &[cp_llbb]); - - // The "null" here is actually a RTTI type descriptor for the - // C++ personality function, but `catch (...)` has no type so - // it's null. The 64 here is actually a bitfield which - // represents that this is a catch-all block. - let mut cp_bx = Bx::build(self.cx, cp_llbb); - let null = cp_bx.const_null( - cp_bx.type_i8p_ext(cp_bx.cx().data_layout().instruction_address_space), - ); - let sixty_four = cp_bx.const_i32(64); - funclet = cp_bx.catch_pad(cs, &[null, sixty_four, null]); - cp_bx.br(llbb); - } - _ => { - let cleanup_llbb = - Bx::append_block(self.cx, self.llfn, &format!("funclet_{:?}", bb)); - ret_llbb = cleanup_llbb; - let mut cleanup_bx = Bx::build(self.cx, cleanup_llbb); - funclet = cleanup_bx.cleanup_pad(None, &[]); - cleanup_bx.br(llbb); - } - } + let cleanup_bb = Bx::append_block(self.cx, self.llfn, &format!("funclet_{:?}", bb)); + let mut cleanup_bx = Bx::build(self.cx, cleanup_bb); + let funclet = cleanup_bx.cleanup_pad(None, &[]); + cleanup_bx.br(llbb); self.funclets[bb] = Some(funclet); - ret_llbb + cleanup_bb } else { let cleanup_llbb = Bx::append_block(self.cx, self.llfn, "cleanup"); let mut cleanup_bx = Bx::build(self.cx, cleanup_llbb); @@ -1636,26 +1585,68 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { }) } - fn double_unwind_guard(&mut self) -> Bx::BasicBlock { - self.double_unwind_guard.unwrap_or_else(|| { - assert!(!base::wants_msvc_seh(self.cx.sess())); + fn terminate_block(&mut self) -> Bx::BasicBlock { + self.terminate_block.unwrap_or_else(|| { + let funclet; + let llbb; + let mut bx; + if base::wants_msvc_seh(self.cx.sess()) { + // This is a basic block that we're aborting the program for, + // notably in an `extern` function. These basic blocks are inserted + // so that we assert that `extern` functions do indeed not panic, + // and if they do we abort the process. + // + // On MSVC these are tricky though (where we're doing funclets). If + // we were to do a cleanuppad (like below) the normal functions like + // `longjmp` would trigger the abort logic, terminating the + // program. Instead we insert the equivalent of `catch(...)` for C++ + // which magically doesn't trigger when `longjmp` files over this + // frame. + // + // Lots more discussion can be found on #48251 but this codegen is + // modeled after clang's for: + // + // try { + // foo(); + // } catch (...) { + // bar(); + // } + llbb = Bx::append_block(self.cx, self.llfn, "cs_terminate"); + let cp_llbb = Bx::append_block(self.cx, self.llfn, "cp_terminate"); + + let mut cs_bx = Bx::build(self.cx, llbb); + let cs = cs_bx.catch_switch(None, None, &[cp_llbb]); + + // The "null" here is actually a RTTI type descriptor for the + // C++ personality function, but `catch (...)` has no type so + // it's null. The 64 here is actually a bitfield which + // represents that this is a catch-all block. + bx = Bx::build(self.cx, cp_llbb); + let null = + bx.const_null(bx.type_i8p_ext(bx.cx().data_layout().instruction_address_space)); + let sixty_four = bx.const_i32(64); + funclet = Some(bx.catch_pad(cs, &[null, sixty_four, null])); + } else { + llbb = Bx::append_block(self.cx, self.llfn, "terminate"); + bx = Bx::build(self.cx, llbb); - let llbb = Bx::append_block(self.cx, self.llfn, "abort"); - let mut bx = Bx::build(self.cx, llbb); - self.set_debug_loc(&mut bx, mir::SourceInfo::outermost(self.mir.span)); + let llpersonality = self.cx.eh_personality(); + bx.cleanup_landing_pad(llpersonality); - let llpersonality = self.cx.eh_personality(); - bx.cleanup_landing_pad(llpersonality); + funclet = None; + } + + self.set_debug_loc(&mut bx, mir::SourceInfo::outermost(self.mir.span)); let (fn_abi, fn_ptr) = common::build_langcall(&bx, None, LangItem::PanicCannotUnwind); let fn_ty = bx.fn_decl_backend_type(&fn_abi); - let llret = bx.call(fn_ty, Some(&fn_abi), fn_ptr, &[], None); + let llret = bx.call(fn_ty, Some(&fn_abi), fn_ptr, &[], funclet.as_ref()); bx.do_not_inline(llret); bx.unreachable(); - self.double_unwind_guard = Some(llbb); + self.terminate_block = Some(llbb); llbb }) } @@ -1698,7 +1689,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { match self.locals[index] { LocalRef::Place(dest) => dest, LocalRef::UnsizedPlace(_) => bug!("return type must be sized"), - LocalRef::Operand(None) => { + LocalRef::PendingOperand => { // Handle temporary places, specifically `Operand` ones, as // they don't have `alloca`s. return if fn_ret.is_indirect() { @@ -1719,7 +1710,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { ReturnDest::DirectOperand(index) }; } - LocalRef::Operand(Some(_)) => { + LocalRef::Operand(_) => { bug!("place local already assigned to"); } } @@ -1746,71 +1737,6 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { } } - fn codegen_transmute(&mut self, bx: &mut Bx, src: &mir::Operand<'tcx>, dst: mir::Place<'tcx>) { - if let Some(index) = dst.as_local() { - match self.locals[index] { - LocalRef::Place(place) => self.codegen_transmute_into(bx, src, place), - LocalRef::UnsizedPlace(_) => bug!("transmute must not involve unsized locals"), - LocalRef::Operand(None) => { - let dst_layout = bx.layout_of(self.monomorphized_place_ty(dst.as_ref())); - assert!(!dst_layout.ty.has_erasable_regions()); - let place = PlaceRef::alloca(bx, dst_layout); - place.storage_live(bx); - self.codegen_transmute_into(bx, src, place); - let op = bx.load_operand(place); - place.storage_dead(bx); - self.locals[index] = LocalRef::Operand(Some(op)); - self.debug_introduce_local(bx, index); - } - LocalRef::Operand(Some(op)) => { - assert!(op.layout.is_zst(), "assigning to initialized SSAtemp"); - } - } - } else { - let dst = self.codegen_place(bx, dst.as_ref()); - self.codegen_transmute_into(bx, src, dst); - } - } - - fn codegen_transmute_into( - &mut self, - bx: &mut Bx, - src: &mir::Operand<'tcx>, - dst: PlaceRef<'tcx, Bx::Value>, - ) { - let src = self.codegen_operand(bx, src); - - // Special-case transmutes between scalars as simple bitcasts. - match (src.layout.abi, dst.layout.abi) { - (abi::Abi::Scalar(src_scalar), abi::Abi::Scalar(dst_scalar)) => { - // HACK(eddyb) LLVM doesn't like `bitcast`s between pointers and non-pointers. - let src_is_ptr = matches!(src_scalar.primitive(), abi::Pointer(_)); - let dst_is_ptr = matches!(dst_scalar.primitive(), abi::Pointer(_)); - if src_is_ptr == dst_is_ptr { - assert_eq!(src.layout.size, dst.layout.size); - - // NOTE(eddyb) the `from_immediate` and `to_immediate_scalar` - // conversions allow handling `bool`s the same as `u8`s. - let src = bx.from_immediate(src.immediate()); - // LLVM also doesn't like `bitcast`s between pointers in different address spaces. - let src_as_dst = if src_is_ptr { - bx.pointercast(src, bx.backend_type(dst.layout)) - } else { - bx.bitcast(src, bx.backend_type(dst.layout)) - }; - Immediate(bx.to_immediate_scalar(src_as_dst, dst_scalar)).store(bx, dst); - return; - } - } - _ => {} - } - - let llty = bx.backend_type(src.layout); - let cast_ptr = bx.pointercast(dst.llval, bx.type_ptr_to(llty)); - let align = src.layout.align.abi.min(dst.align); - src.val.store(bx, PlaceRef::new_sized_aligned(cast_ptr, src.layout, align)); - } - // Stores the return value of a function call into it's final location. fn store_return( &mut self, @@ -1827,7 +1753,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { IndirectOperand(tmp, index) => { let op = bx.load_operand(tmp); tmp.storage_dead(bx); - self.locals[index] = LocalRef::Operand(Some(op)); + self.locals[index] = LocalRef::Operand(op); self.debug_introduce_local(bx, index); } DirectOperand(index) => { @@ -1842,7 +1768,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { } else { OperandRef::from_immediate_or_packed_pair(bx, llval, ret_abi.layout) }; - self.locals[index] = LocalRef::Operand(Some(op)); + self.locals[index] = LocalRef::Operand(op); self.debug_introduce_local(bx, index); } } |