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-rw-r--r--compiler/rustc_codegen_ssa/src/mir/block.rs1654
1 files changed, 1654 insertions, 0 deletions
diff --git a/compiler/rustc_codegen_ssa/src/mir/block.rs b/compiler/rustc_codegen_ssa/src/mir/block.rs
new file mode 100644
index 000000000..3eee58d9d
--- /dev/null
+++ b/compiler/rustc_codegen_ssa/src/mir/block.rs
@@ -0,0 +1,1654 @@
+use super::operand::OperandRef;
+use super::operand::OperandValue::{Immediate, Pair, Ref};
+use super::place::PlaceRef;
+use super::{FunctionCx, LocalRef};
+
+use crate::base;
+use crate::common::{self, IntPredicate};
+use crate::meth;
+use crate::traits::*;
+use crate::MemFlags;
+
+use rustc_ast as ast;
+use rustc_ast::{InlineAsmOptions, InlineAsmTemplatePiece};
+use rustc_hir::lang_items::LangItem;
+use rustc_index::vec::Idx;
+use rustc_middle::mir::AssertKind;
+use rustc_middle::mir::{self, SwitchTargets};
+use rustc_middle::ty::layout::{HasTyCtxt, LayoutOf};
+use rustc_middle::ty::print::{with_no_trimmed_paths, with_no_visible_paths};
+use rustc_middle::ty::{self, Instance, Ty, TypeVisitable};
+use rustc_span::source_map::Span;
+use rustc_span::{sym, Symbol};
+use rustc_symbol_mangling::typeid::typeid_for_fnabi;
+use rustc_target::abi::call::{ArgAbi, FnAbi, PassMode};
+use rustc_target::abi::{self, HasDataLayout, WrappingRange};
+use rustc_target::spec::abi::Abi;
+
+/// Used by `FunctionCx::codegen_terminator` for emitting common patterns
+/// e.g., creating a basic block, calling a function, etc.
+struct TerminatorCodegenHelper<'tcx> {
+ bb: mir::BasicBlock,
+ terminator: &'tcx mir::Terminator<'tcx>,
+ funclet_bb: Option<mir::BasicBlock>,
+}
+
+impl<'a, 'tcx> TerminatorCodegenHelper<'tcx> {
+ /// Returns the appropriate `Funclet` for the current funclet, if on MSVC,
+ /// either already previously cached, or newly created, by `landing_pad_for`.
+ fn funclet<'b, Bx: BuilderMethods<'a, 'tcx>>(
+ &self,
+ fx: &'b mut FunctionCx<'a, 'tcx, Bx>,
+ ) -> Option<&'b Bx::Funclet> {
+ let funclet_bb = self.funclet_bb?;
+ if base::wants_msvc_seh(fx.cx.tcx().sess) {
+ // If `landing_pad_for` hasn't been called yet to create the `Funclet`,
+ // it has to be now. This may not seem necessary, as RPO should lead
+ // to all the unwind edges being visited (and so to `landing_pad_for`
+ // getting called for them), before building any of the blocks inside
+ // the funclet itself - however, if MIR contains edges that end up not
+ // being needed in the LLVM IR after monomorphization, the funclet may
+ // be unreachable, and we don't have yet a way to skip building it in
+ // such an eventuality (which may be a better solution than this).
+ if fx.funclets[funclet_bb].is_none() {
+ fx.landing_pad_for(funclet_bb);
+ }
+
+ Some(
+ fx.funclets[funclet_bb]
+ .as_ref()
+ .expect("landing_pad_for didn't also create funclets entry"),
+ )
+ } else {
+ None
+ }
+ }
+
+ fn lltarget<Bx: BuilderMethods<'a, 'tcx>>(
+ &self,
+ fx: &mut FunctionCx<'a, 'tcx, Bx>,
+ target: mir::BasicBlock,
+ ) -> (Bx::BasicBlock, bool) {
+ let span = self.terminator.source_info.span;
+ let lltarget = fx.llbb(target);
+ let target_funclet = fx.cleanup_kinds[target].funclet_bb(target);
+ match (self.funclet_bb, target_funclet) {
+ (None, None) => (lltarget, false),
+ (Some(f), Some(t_f)) if f == t_f || !base::wants_msvc_seh(fx.cx.tcx().sess) => {
+ (lltarget, false)
+ }
+ // jump *into* cleanup - need a landing pad if GNU, cleanup pad if MSVC
+ (None, Some(_)) => (fx.landing_pad_for(target), false),
+ (Some(_), None) => span_bug!(span, "{:?} - jump out of cleanup?", self.terminator),
+ (Some(_), Some(_)) => (fx.landing_pad_for(target), true),
+ }
+ }
+
+ /// Create a basic block.
+ fn llblock<Bx: BuilderMethods<'a, 'tcx>>(
+ &self,
+ fx: &mut FunctionCx<'a, 'tcx, Bx>,
+ target: mir::BasicBlock,
+ ) -> Bx::BasicBlock {
+ let (lltarget, is_cleanupret) = self.lltarget(fx, target);
+ if is_cleanupret {
+ // MSVC cross-funclet jump - need a trampoline
+
+ debug!("llblock: creating cleanup trampoline for {:?}", target);
+ let name = &format!("{:?}_cleanup_trampoline_{:?}", self.bb, target);
+ let trampoline = Bx::append_block(fx.cx, fx.llfn, name);
+ let mut trampoline_bx = Bx::build(fx.cx, trampoline);
+ trampoline_bx.cleanup_ret(self.funclet(fx).unwrap(), Some(lltarget));
+ trampoline
+ } else {
+ lltarget
+ }
+ }
+
+ fn funclet_br<Bx: BuilderMethods<'a, 'tcx>>(
+ &self,
+ fx: &mut FunctionCx<'a, 'tcx, Bx>,
+ bx: &mut Bx,
+ target: mir::BasicBlock,
+ ) {
+ let (lltarget, is_cleanupret) = self.lltarget(fx, target);
+ if is_cleanupret {
+ // micro-optimization: generate a `ret` rather than a jump
+ // to a trampoline.
+ bx.cleanup_ret(self.funclet(fx).unwrap(), Some(lltarget));
+ } else {
+ bx.br(lltarget);
+ }
+ }
+
+ /// Call `fn_ptr` of `fn_abi` with the arguments `llargs`, the optional
+ /// return destination `destination` and the cleanup function `cleanup`.
+ fn do_call<Bx: BuilderMethods<'a, 'tcx>>(
+ &self,
+ fx: &mut FunctionCx<'a, 'tcx, Bx>,
+ bx: &mut Bx,
+ fn_abi: &'tcx FnAbi<'tcx, Ty<'tcx>>,
+ fn_ptr: Bx::Value,
+ llargs: &[Bx::Value],
+ destination: Option<(ReturnDest<'tcx, Bx::Value>, mir::BasicBlock)>,
+ cleanup: Option<mir::BasicBlock>,
+ copied_constant_arguments: &[PlaceRef<'tcx, <Bx as BackendTypes>::Value>],
+ ) {
+ // If there is a cleanup block and the function we're calling can unwind, then
+ // 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.llblock(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 let Some(unwind_block) = unwind_block {
+ let ret_llbb = if let Some((_, target)) = destination {
+ fx.llbb(target)
+ } else {
+ fx.unreachable_block()
+ };
+ let invokeret =
+ bx.invoke(fn_ty, fn_ptr, &llargs, ret_llbb, unwind_block, self.funclet(fx));
+ bx.apply_attrs_callsite(&fn_abi, invokeret);
+ if fx.mir[self.bb].is_cleanup {
+ bx.do_not_inline(invokeret);
+ }
+
+ if let Some((ret_dest, target)) = destination {
+ bx.switch_to_block(fx.llbb(target));
+ fx.set_debug_loc(bx, self.terminator.source_info);
+ for tmp in copied_constant_arguments {
+ bx.lifetime_end(tmp.llval, tmp.layout.size);
+ }
+ fx.store_return(bx, ret_dest, &fn_abi.ret, invokeret);
+ }
+ } else {
+ let llret = bx.call(fn_ty, fn_ptr, &llargs, self.funclet(fx));
+ bx.apply_attrs_callsite(&fn_abi, llret);
+ if fx.mir[self.bb].is_cleanup {
+ // Cleanup is always the cold path. Don't inline
+ // drop glue. Also, when there is a deeply-nested
+ // struct, there are "symmetry" issues that cause
+ // exponential inlining - see issue #41696.
+ bx.do_not_inline(llret);
+ }
+
+ if let Some((ret_dest, target)) = destination {
+ for tmp in copied_constant_arguments {
+ bx.lifetime_end(tmp.llval, tmp.layout.size);
+ }
+ fx.store_return(bx, ret_dest, &fn_abi.ret, llret);
+ self.funclet_br(fx, bx, target);
+ } else {
+ bx.unreachable();
+ }
+ }
+ }
+
+ /// Generates inline assembly with optional `destination` and `cleanup`.
+ fn do_inlineasm<Bx: BuilderMethods<'a, 'tcx>>(
+ &self,
+ fx: &mut FunctionCx<'a, 'tcx, Bx>,
+ bx: &mut Bx,
+ template: &[InlineAsmTemplatePiece],
+ operands: &[InlineAsmOperandRef<'tcx, Bx>],
+ options: InlineAsmOptions,
+ line_spans: &[Span],
+ destination: Option<mir::BasicBlock>,
+ cleanup: Option<mir::BasicBlock>,
+ instance: Instance<'_>,
+ ) {
+ if let Some(cleanup) = cleanup {
+ let ret_llbb = if let Some(target) = destination {
+ fx.llbb(target)
+ } else {
+ fx.unreachable_block()
+ };
+
+ bx.codegen_inline_asm(
+ template,
+ &operands,
+ options,
+ line_spans,
+ instance,
+ Some((ret_llbb, self.llblock(fx, cleanup), self.funclet(fx))),
+ );
+ } else {
+ bx.codegen_inline_asm(template, &operands, options, line_spans, instance, None);
+
+ if let Some(target) = destination {
+ self.funclet_br(fx, bx, target);
+ } else {
+ bx.unreachable();
+ }
+ }
+ }
+}
+
+/// Codegen implementations for some terminator variants.
+impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
+ /// Generates code for a `Resume` terminator.
+ fn codegen_resume_terminator(&mut self, helper: TerminatorCodegenHelper<'tcx>, mut bx: Bx) {
+ if let Some(funclet) = helper.funclet(self) {
+ bx.cleanup_ret(funclet, None);
+ } else {
+ let slot = self.get_personality_slot(&mut bx);
+ let lp0 = slot.project_field(&mut bx, 0);
+ let lp0 = bx.load_operand(lp0).immediate();
+ let lp1 = slot.project_field(&mut bx, 1);
+ let lp1 = bx.load_operand(lp1).immediate();
+ slot.storage_dead(&mut bx);
+
+ let mut lp = bx.const_undef(self.landing_pad_type());
+ lp = bx.insert_value(lp, lp0, 0);
+ lp = bx.insert_value(lp, lp1, 1);
+ bx.resume(lp);
+ }
+ }
+
+ fn codegen_switchint_terminator(
+ &mut self,
+ helper: TerminatorCodegenHelper<'tcx>,
+ mut bx: Bx,
+ discr: &mir::Operand<'tcx>,
+ switch_ty: Ty<'tcx>,
+ targets: &SwitchTargets,
+ ) {
+ let discr = self.codegen_operand(&mut bx, &discr);
+ // `switch_ty` is redundant, sanity-check that.
+ assert_eq!(discr.layout.ty, switch_ty);
+ let mut target_iter = targets.iter();
+ if target_iter.len() == 1 {
+ // If there are two targets (one conditional, one fallback), emit br instead of switch
+ let (test_value, target) = target_iter.next().unwrap();
+ let lltrue = helper.llblock(self, target);
+ let llfalse = helper.llblock(self, targets.otherwise());
+ if switch_ty == bx.tcx().types.bool {
+ // Don't generate trivial icmps when switching on bool
+ match test_value {
+ 0 => bx.cond_br(discr.immediate(), llfalse, lltrue),
+ 1 => bx.cond_br(discr.immediate(), lltrue, llfalse),
+ _ => bug!(),
+ }
+ } else {
+ let switch_llty = bx.immediate_backend_type(bx.layout_of(switch_ty));
+ let llval = bx.const_uint_big(switch_llty, test_value);
+ let cmp = bx.icmp(IntPredicate::IntEQ, discr.immediate(), llval);
+ bx.cond_br(cmp, lltrue, llfalse);
+ }
+ } else {
+ bx.switch(
+ discr.immediate(),
+ helper.llblock(self, targets.otherwise()),
+ target_iter.map(|(value, target)| (value, helper.llblock(self, target))),
+ );
+ }
+ }
+
+ fn codegen_return_terminator(&mut self, mut bx: Bx) {
+ // Call `va_end` if this is the definition of a C-variadic function.
+ if self.fn_abi.c_variadic {
+ // The `VaList` "spoofed" argument is just after all the real arguments.
+ let va_list_arg_idx = self.fn_abi.args.len();
+ match self.locals[mir::Local::new(1 + va_list_arg_idx)] {
+ LocalRef::Place(va_list) => {
+ bx.va_end(va_list.llval);
+ }
+ _ => bug!("C-variadic function must have a `VaList` place"),
+ }
+ }
+ if self.fn_abi.ret.layout.abi.is_uninhabited() {
+ // Functions with uninhabited return values are marked `noreturn`,
+ // so we should make sure that we never actually do.
+ // We play it safe by using a well-defined `abort`, but we could go for immediate UB
+ // if that turns out to be helpful.
+ bx.abort();
+ // `abort` does not terminate the block, so we still need to generate
+ // an `unreachable` terminator after it.
+ bx.unreachable();
+ return;
+ }
+ let llval = match self.fn_abi.ret.mode {
+ PassMode::Ignore | PassMode::Indirect { .. } => {
+ bx.ret_void();
+ return;
+ }
+
+ PassMode::Direct(_) | PassMode::Pair(..) => {
+ let op = self.codegen_consume(&mut bx, mir::Place::return_place().as_ref());
+ if let Ref(llval, _, align) = op.val {
+ bx.load(bx.backend_type(op.layout), llval, align)
+ } else {
+ op.immediate_or_packed_pair(&mut 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::Place(cg_place) => OperandRef {
+ val: Ref(cg_place.llval, None, cg_place.align),
+ layout: cg_place.layout,
+ },
+ LocalRef::UnsizedPlace(_) => bug!("return type must be sized"),
+ };
+ let llslot = match op.val {
+ Immediate(_) | Pair(..) => {
+ let scratch = PlaceRef::alloca(&mut bx, self.fn_abi.ret.layout);
+ op.val.store(&mut bx, scratch);
+ scratch.llval
+ }
+ Ref(llval, _, align) => {
+ assert_eq!(align, op.layout.align.abi, "return place is unaligned!");
+ llval
+ }
+ };
+ let ty = bx.cast_backend_type(&cast_ty);
+ let addr = bx.pointercast(llslot, bx.type_ptr_to(ty));
+ bx.load(ty, addr, self.fn_abi.ret.layout.align.abi)
+ }
+ };
+ bx.ret(llval);
+ }
+
+ fn codegen_drop_terminator(
+ &mut self,
+ helper: TerminatorCodegenHelper<'tcx>,
+ mut bx: Bx,
+ location: mir::Place<'tcx>,
+ target: mir::BasicBlock,
+ unwind: Option<mir::BasicBlock>,
+ ) {
+ let ty = location.ty(self.mir, bx.tcx()).ty;
+ let ty = self.monomorphize(ty);
+ let drop_fn = Instance::resolve_drop_in_place(bx.tcx(), ty);
+
+ if let ty::InstanceDef::DropGlue(_, None) = drop_fn.def {
+ // we don't actually need to drop anything.
+ helper.funclet_br(self, &mut bx, target);
+ return;
+ }
+
+ let place = self.codegen_place(&mut bx, location.as_ref());
+ let (args1, args2);
+ let mut args = if let Some(llextra) = place.llextra {
+ args2 = [place.llval, llextra];
+ &args2[..]
+ } else {
+ args1 = [place.llval];
+ &args1[..]
+ };
+ let (drop_fn, fn_abi) = match ty.kind() {
+ // FIXME(eddyb) perhaps move some of this logic into
+ // `Instance::resolve_drop_in_place`?
+ ty::Dynamic(..) => {
+ let virtual_drop = Instance {
+ def: ty::InstanceDef::Virtual(drop_fn.def_id(), 0),
+ substs: drop_fn.substs,
+ };
+ let fn_abi = bx.fn_abi_of_instance(virtual_drop, ty::List::empty());
+ let vtable = args[1];
+ args = &args[..1];
+ (
+ meth::VirtualIndex::from_index(ty::COMMON_VTABLE_ENTRIES_DROPINPLACE)
+ .get_fn(&mut bx, vtable, ty, &fn_abi),
+ fn_abi,
+ )
+ }
+ _ => (bx.get_fn_addr(drop_fn), bx.fn_abi_of_instance(drop_fn, ty::List::empty())),
+ };
+ helper.do_call(
+ self,
+ &mut bx,
+ fn_abi,
+ drop_fn,
+ args,
+ Some((ReturnDest::Nothing, target)),
+ unwind,
+ &[],
+ );
+ }
+
+ fn codegen_assert_terminator(
+ &mut self,
+ helper: TerminatorCodegenHelper<'tcx>,
+ mut bx: Bx,
+ terminator: &mir::Terminator<'tcx>,
+ cond: &mir::Operand<'tcx>,
+ expected: bool,
+ msg: &mir::AssertMessage<'tcx>,
+ target: mir::BasicBlock,
+ cleanup: Option<mir::BasicBlock>,
+ ) {
+ let span = terminator.source_info.span;
+ let cond = self.codegen_operand(&mut bx, cond).immediate();
+ let mut const_cond = bx.const_to_opt_u128(cond, false).map(|c| c == 1);
+
+ // This case can currently arise only from functions marked
+ // 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.
+ // NOTE: Unlike binops, negation doesn't have its own
+ // checked operation, just a comparison with the minimum
+ // value, so we have to check for the assert message.
+ if !bx.check_overflow() {
+ if let AssertKind::OverflowNeg(_) = *msg {
+ const_cond = Some(expected);
+ }
+ }
+
+ // Don't codegen the panic block if success if known.
+ if const_cond == Some(expected) {
+ helper.funclet_br(self, &mut bx, target);
+ return;
+ }
+
+ // Pass the condition through llvm.expect for branch hinting.
+ let cond = bx.expect(cond, expected);
+
+ // Create the failure block and the conditional branch to it.
+ let lltarget = helper.llblock(self, target);
+ let panic_block = bx.append_sibling_block("panic");
+ if expected {
+ bx.cond_br(cond, lltarget, panic_block);
+ } else {
+ bx.cond_br(cond, panic_block, lltarget);
+ }
+
+ // After this point, bx is the block for the call to panic.
+ bx.switch_to_block(panic_block);
+ self.set_debug_loc(&mut bx, terminator.source_info);
+
+ // Get the location information.
+ let location = self.get_caller_location(&mut bx, terminator.source_info).immediate();
+
+ // Put together the arguments to the panic entry point.
+ let (lang_item, args) = match msg {
+ AssertKind::BoundsCheck { ref len, ref index } => {
+ let len = self.codegen_operand(&mut bx, len).immediate();
+ let index = self.codegen_operand(&mut bx, index).immediate();
+ // It's `fn panic_bounds_check(index: usize, len: usize)`,
+ // and `#[track_caller]` adds an implicit third argument.
+ (LangItem::PanicBoundsCheck, vec![index, len, location])
+ }
+ _ => {
+ let msg = bx.const_str(msg.description());
+ // It's `pub fn panic(expr: &str)`, with the wide reference being passed
+ // as two arguments, and `#[track_caller]` adds an implicit third argument.
+ (LangItem::Panic, vec![msg.0, msg.1, location])
+ }
+ };
+
+ let (fn_abi, llfn) = common::build_langcall(&bx, Some(span), lang_item);
+
+ // Codegen the actual panic invoke/call.
+ helper.do_call(self, &mut bx, fn_abi, llfn, &args, None, cleanup, &[]);
+ }
+
+ fn codegen_abort_terminator(
+ &mut self,
+ helper: TerminatorCodegenHelper<'tcx>,
+ mut bx: Bx,
+ terminator: &mir::Terminator<'tcx>,
+ ) {
+ let span = terminator.source_info.span;
+ self.set_debug_loc(&mut bx, terminator.source_info);
+
+ // Obtain the panic entry point.
+ let (fn_abi, llfn) = common::build_langcall(&bx, Some(span), LangItem::PanicNoUnwind);
+
+ // Codegen the actual panic invoke/call.
+ helper.do_call(self, &mut bx, fn_abi, llfn, &[], None, None, &[]);
+ }
+
+ /// Returns `true` if this is indeed a panic intrinsic and codegen is done.
+ fn codegen_panic_intrinsic(
+ &mut self,
+ helper: &TerminatorCodegenHelper<'tcx>,
+ bx: &mut Bx,
+ intrinsic: Option<Symbol>,
+ instance: Option<Instance<'tcx>>,
+ source_info: mir::SourceInfo,
+ target: Option<mir::BasicBlock>,
+ cleanup: Option<mir::BasicBlock>,
+ ) -> bool {
+ // Emit a panic or a no-op for `assert_*` intrinsics.
+ // These are intrinsics that compile to panics so that we can get a message
+ // which mentions the offending type, even from a const context.
+ #[derive(Debug, PartialEq)]
+ enum AssertIntrinsic {
+ Inhabited,
+ ZeroValid,
+ UninitValid,
+ }
+ let panic_intrinsic = intrinsic.and_then(|i| match i {
+ sym::assert_inhabited => Some(AssertIntrinsic::Inhabited),
+ sym::assert_zero_valid => Some(AssertIntrinsic::ZeroValid),
+ sym::assert_uninit_valid => Some(AssertIntrinsic::UninitValid),
+ _ => None,
+ });
+ if let Some(intrinsic) = panic_intrinsic {
+ use AssertIntrinsic::*;
+
+ let ty = instance.unwrap().substs.type_at(0);
+ let layout = bx.layout_of(ty);
+ let do_panic = match intrinsic {
+ Inhabited => layout.abi.is_uninhabited(),
+ ZeroValid => !bx.tcx().permits_zero_init(layout),
+ UninitValid => !bx.tcx().permits_uninit_init(layout),
+ };
+ if do_panic {
+ let msg_str = with_no_visible_paths!({
+ with_no_trimmed_paths!({
+ if layout.abi.is_uninhabited() {
+ // Use this error even for the other intrinsics as it is more precise.
+ format!("attempted to instantiate uninhabited type `{}`", ty)
+ } else if intrinsic == ZeroValid {
+ format!("attempted to zero-initialize type `{}`, which is invalid", ty)
+ } else {
+ format!(
+ "attempted to leave type `{}` uninitialized, which is invalid",
+ ty
+ )
+ }
+ })
+ });
+ let msg = bx.const_str(&msg_str);
+ let location = self.get_caller_location(bx, source_info).immediate();
+
+ // Obtain the panic entry point.
+ let (fn_abi, llfn) =
+ common::build_langcall(bx, Some(source_info.span), LangItem::Panic);
+
+ // Codegen the actual panic invoke/call.
+ helper.do_call(
+ self,
+ bx,
+ fn_abi,
+ llfn,
+ &[msg.0, msg.1, location],
+ target.as_ref().map(|bb| (ReturnDest::Nothing, *bb)),
+ cleanup,
+ &[],
+ );
+ } else {
+ // a NOP
+ let target = target.unwrap();
+ helper.funclet_br(self, bx, target)
+ }
+ true
+ } else {
+ false
+ }
+ }
+
+ fn codegen_call_terminator(
+ &mut self,
+ helper: TerminatorCodegenHelper<'tcx>,
+ mut bx: Bx,
+ terminator: &mir::Terminator<'tcx>,
+ func: &mir::Operand<'tcx>,
+ args: &[mir::Operand<'tcx>],
+ destination: mir::Place<'tcx>,
+ target: Option<mir::BasicBlock>,
+ cleanup: Option<mir::BasicBlock>,
+ fn_span: Span,
+ ) {
+ let source_info = terminator.source_info;
+ let span = source_info.span;
+
+ // Create the callee. This is a fn ptr or zero-sized and hence a kind of scalar.
+ let callee = self.codegen_operand(&mut bx, func);
+
+ let (instance, mut llfn) = match *callee.layout.ty.kind() {
+ ty::FnDef(def_id, substs) => (
+ Some(
+ ty::Instance::resolve(bx.tcx(), ty::ParamEnv::reveal_all(), def_id, substs)
+ .unwrap()
+ .unwrap()
+ .polymorphize(bx.tcx()),
+ ),
+ None,
+ ),
+ ty::FnPtr(_) => (None, Some(callee.immediate())),
+ _ => bug!("{} is not callable", callee.layout.ty),
+ };
+ let def = instance.map(|i| i.def);
+
+ if let Some(ty::InstanceDef::DropGlue(_, None)) = def {
+ // Empty drop glue; a no-op.
+ let target = target.unwrap();
+ helper.funclet_br(self, &mut bx, target);
+ return;
+ }
+
+ // FIXME(eddyb) avoid computing this if possible, when `instance` is
+ // available - right now `sig` is only needed for getting the `abi`
+ // and figuring out how many extra args were passed to a C-variadic `fn`.
+ let sig = callee.layout.ty.fn_sig(bx.tcx());
+ let abi = sig.abi();
+
+ // Handle intrinsics old codegen wants Expr's for, ourselves.
+ let intrinsic = match def {
+ Some(ty::InstanceDef::Intrinsic(def_id)) => Some(bx.tcx().item_name(def_id)),
+ _ => None,
+ };
+
+ let extra_args = &args[sig.inputs().skip_binder().len()..];
+ let extra_args = bx.tcx().mk_type_list(extra_args.iter().map(|op_arg| {
+ let op_ty = op_arg.ty(self.mir, bx.tcx());
+ self.monomorphize(op_ty)
+ }));
+
+ let fn_abi = match instance {
+ Some(instance) => bx.fn_abi_of_instance(instance, extra_args),
+ None => bx.fn_abi_of_fn_ptr(sig, extra_args),
+ };
+
+ if intrinsic == Some(sym::transmute) {
+ if let Some(target) = target {
+ self.codegen_transmute(&mut bx, &args[0], destination);
+ helper.funclet_br(self, &mut bx, target);
+ } 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();
+ }
+ return;
+ }
+
+ if self.codegen_panic_intrinsic(
+ &helper,
+ &mut bx,
+ intrinsic,
+ instance,
+ source_info,
+ target,
+ cleanup,
+ ) {
+ return;
+ }
+
+ // The arguments we'll be passing. Plus one to account for outptr, if used.
+ let arg_count = fn_abi.args.len() + fn_abi.ret.is_indirect() as usize;
+ let mut llargs = Vec::with_capacity(arg_count);
+
+ // Prepare the return value destination
+ let ret_dest = if target.is_some() {
+ let is_intrinsic = intrinsic.is_some();
+ self.make_return_dest(&mut bx, destination, &fn_abi.ret, &mut llargs, is_intrinsic)
+ } else {
+ ReturnDest::Nothing
+ };
+
+ if intrinsic == Some(sym::caller_location) {
+ if let Some(target) = target {
+ let location = self
+ .get_caller_location(&mut bx, mir::SourceInfo { span: fn_span, ..source_info });
+
+ if let ReturnDest::IndirectOperand(tmp, _) = ret_dest {
+ location.val.store(&mut bx, tmp);
+ }
+ self.store_return(&mut bx, ret_dest, &fn_abi.ret, location.immediate());
+ helper.funclet_br(self, &mut bx, target);
+ }
+ return;
+ }
+
+ 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],
+ ReturnDest::Nothing => {
+ bx.const_undef(bx.type_ptr_to(bx.arg_memory_ty(&fn_abi.ret)))
+ }
+ ReturnDest::IndirectOperand(dst, _) | ReturnDest::Store(dst) => dst.llval,
+ ReturnDest::DirectOperand(_) => {
+ bug!("Cannot use direct operand with an intrinsic call")
+ }
+ };
+
+ let args: Vec<_> = args
+ .iter()
+ .enumerate()
+ .map(|(i, arg)| {
+ // The indices passed to simd_shuffle* in the
+ // third argument must be constant. This is
+ // checked by const-qualification, which also
+ // promotes any complex rvalues to constants.
+ if i == 2 && intrinsic.as_str().starts_with("simd_shuffle") {
+ if let mir::Operand::Constant(constant) = arg {
+ let c = self.eval_mir_constant(constant);
+ let (llval, ty) = self.simd_shuffle_indices(
+ &bx,
+ constant.span,
+ self.monomorphize(constant.ty()),
+ c,
+ );
+ return OperandRef {
+ val: Immediate(llval),
+ layout: bx.layout_of(ty),
+ };
+ } else {
+ span_bug!(span, "shuffle indices must be constant");
+ }
+ }
+
+ self.codegen_operand(&mut bx, arg)
+ })
+ .collect();
+
+ Self::codegen_intrinsic_call(
+ &mut bx,
+ *instance.as_ref().unwrap(),
+ &fn_abi,
+ &args,
+ dest,
+ span,
+ );
+
+ if let ReturnDest::IndirectOperand(dst, _) = ret_dest {
+ self.store_return(&mut bx, ret_dest, &fn_abi.ret, dst.llval);
+ }
+
+ if let Some(target) = target {
+ helper.funclet_br(self, &mut bx, target);
+ } else {
+ bx.unreachable();
+ }
+
+ return;
+ }
+ }
+
+ // Split the rust-call tupled arguments off.
+ let (first_args, untuple) = if abi == Abi::RustCall && !args.is_empty() {
+ let (tup, args) = args.split_last().unwrap();
+ (args, Some(tup))
+ } else {
+ (args, None)
+ };
+
+ let mut copied_constant_arguments = vec![];
+ 'make_args: for (i, arg) in first_args.iter().enumerate() {
+ let mut op = self.codegen_operand(&mut bx, arg);
+
+ if let (0, Some(ty::InstanceDef::Virtual(_, idx))) = (i, def) {
+ if let Pair(..) = op.val {
+ // In the case of Rc<Self>, we need to explicitly pass a
+ // *mut RcBox<Self> with a Scalar (not ScalarPair) ABI. This is a hack
+ // that is understood elsewhere in the compiler as a method on
+ // `dyn Trait`.
+ // To get a `*mut RcBox<Self>`, we just keep unwrapping newtypes until
+ // we get a value of a built-in pointer type
+ 'descend_newtypes: while !op.layout.ty.is_unsafe_ptr()
+ && !op.layout.ty.is_region_ptr()
+ {
+ for i in 0..op.layout.fields.count() {
+ let field = op.extract_field(&mut bx, i);
+ if !field.layout.is_zst() {
+ // we found the one non-zero-sized field that is allowed
+ // now find *its* non-zero-sized field, or stop if it's a
+ // pointer
+ op = field;
+ continue 'descend_newtypes;
+ }
+ }
+
+ span_bug!(span, "receiver has no non-zero-sized fields {:?}", op);
+ }
+
+ // now that we have `*dyn Trait` or `&dyn Trait`, split it up into its
+ // data pointer and vtable. Look up the method in the vtable, and pass
+ // the data pointer as the first argument
+ match op.val {
+ Pair(data_ptr, meta) => {
+ llfn = Some(meth::VirtualIndex::from_index(idx).get_fn(
+ &mut bx,
+ meta,
+ op.layout.ty,
+ &fn_abi,
+ ));
+ llargs.push(data_ptr);
+ continue 'make_args;
+ }
+ other => bug!("expected a Pair, got {:?}", other),
+ }
+ } else if let Ref(data_ptr, Some(meta), _) = op.val {
+ // by-value dynamic dispatch
+ llfn = Some(meth::VirtualIndex::from_index(idx).get_fn(
+ &mut bx,
+ meta,
+ op.layout.ty,
+ &fn_abi,
+ ));
+ llargs.push(data_ptr);
+ continue;
+ } else {
+ span_bug!(span, "can't codegen a virtual call on {:?}", op);
+ }
+ }
+
+ // The callee needs to own the argument memory if we pass it
+ // by-ref, so make a local copy of non-immediate constants.
+ match (arg, op.val) {
+ (&mir::Operand::Copy(_), Ref(_, None, _))
+ | (&mir::Operand::Constant(_), Ref(_, None, _)) => {
+ let tmp = PlaceRef::alloca(&mut bx, op.layout);
+ bx.lifetime_start(tmp.llval, tmp.layout.size);
+ op.val.store(&mut bx, tmp);
+ op.val = Ref(tmp.llval, None, tmp.align);
+ copied_constant_arguments.push(tmp);
+ }
+ _ => {}
+ }
+
+ self.codegen_argument(&mut bx, op, &mut llargs, &fn_abi.args[i]);
+ }
+ let num_untupled = untuple.map(|tup| {
+ self.codegen_arguments_untupled(
+ &mut bx,
+ tup,
+ &mut llargs,
+ &fn_abi.args[first_args.len()..],
+ )
+ });
+
+ let needs_location =
+ instance.map_or(false, |i| i.def.requires_caller_location(self.cx.tcx()));
+ if needs_location {
+ let mir_args = if let Some(num_untupled) = num_untupled {
+ first_args.len() + num_untupled
+ } else {
+ args.len()
+ };
+ assert_eq!(
+ fn_abi.args.len(),
+ mir_args + 1,
+ "#[track_caller] fn's must have 1 more argument in their ABI than in their MIR: {:?} {:?} {:?}",
+ instance,
+ fn_span,
+ fn_abi,
+ );
+ let location =
+ self.get_caller_location(&mut bx, mir::SourceInfo { span: fn_span, ..source_info });
+ debug!(
+ "codegen_call_terminator({:?}): location={:?} (fn_span {:?})",
+ terminator, location, fn_span
+ );
+
+ let last_arg = fn_abi.args.last().unwrap();
+ self.codegen_argument(&mut bx, location, &mut llargs, last_arg);
+ }
+
+ let (is_indirect_call, fn_ptr) = match (llfn, instance) {
+ (Some(llfn), _) => (true, llfn),
+ (None, Some(instance)) => (false, bx.get_fn_addr(instance)),
+ _ => span_bug!(span, "no llfn for call"),
+ };
+
+ // For backends that support CFI using type membership (i.e., testing whether a given
+ // pointer is associated with a type identifier).
+ if bx.tcx().sess.is_sanitizer_cfi_enabled() && is_indirect_call {
+ // Emit type metadata and checks.
+ // FIXME(rcvalle): Add support for generalized identifiers.
+ // FIXME(rcvalle): Create distinct unnamed MDNodes for internal identifiers.
+ let typeid = typeid_for_fnabi(bx.tcx(), fn_abi);
+ let typeid_metadata = self.cx.typeid_metadata(typeid);
+
+ // Test whether the function pointer is associated with the type identifier.
+ let cond = bx.type_test(fn_ptr, typeid_metadata);
+ let bb_pass = bx.append_sibling_block("type_test.pass");
+ let bb_fail = bx.append_sibling_block("type_test.fail");
+ bx.cond_br(cond, bb_pass, bb_fail);
+
+ bx.switch_to_block(bb_pass);
+ helper.do_call(
+ self,
+ &mut bx,
+ fn_abi,
+ fn_ptr,
+ &llargs,
+ target.as_ref().map(|&target| (ret_dest, target)),
+ cleanup,
+ &copied_constant_arguments,
+ );
+
+ bx.switch_to_block(bb_fail);
+ bx.abort();
+ bx.unreachable();
+
+ return;
+ }
+
+ helper.do_call(
+ self,
+ &mut bx,
+ fn_abi,
+ fn_ptr,
+ &llargs,
+ target.as_ref().map(|&target| (ret_dest, target)),
+ cleanup,
+ &copied_constant_arguments,
+ );
+ }
+
+ fn codegen_asm_terminator(
+ &mut self,
+ helper: TerminatorCodegenHelper<'tcx>,
+ mut bx: Bx,
+ terminator: &mir::Terminator<'tcx>,
+ template: &[ast::InlineAsmTemplatePiece],
+ operands: &[mir::InlineAsmOperand<'tcx>],
+ options: ast::InlineAsmOptions,
+ line_spans: &[Span],
+ destination: Option<mir::BasicBlock>,
+ cleanup: Option<mir::BasicBlock>,
+ instance: Instance<'_>,
+ ) {
+ let span = terminator.source_info.span;
+
+ let operands: Vec<_> = operands
+ .iter()
+ .map(|op| match *op {
+ mir::InlineAsmOperand::In { reg, ref value } => {
+ let value = self.codegen_operand(&mut bx, value);
+ InlineAsmOperandRef::In { reg, value }
+ }
+ mir::InlineAsmOperand::Out { reg, late, ref place } => {
+ let place = place.map(|place| self.codegen_place(&mut bx, place.as_ref()));
+ InlineAsmOperandRef::Out { reg, late, place }
+ }
+ mir::InlineAsmOperand::InOut { reg, late, ref in_value, ref out_place } => {
+ let in_value = self.codegen_operand(&mut bx, in_value);
+ let out_place =
+ out_place.map(|out_place| self.codegen_place(&mut bx, out_place.as_ref()));
+ InlineAsmOperandRef::InOut { reg, late, in_value, out_place }
+ }
+ mir::InlineAsmOperand::Const { ref value } => {
+ let const_value = self
+ .eval_mir_constant(value)
+ .unwrap_or_else(|_| span_bug!(span, "asm const cannot be resolved"));
+ let string = common::asm_const_to_str(
+ bx.tcx(),
+ span,
+ const_value,
+ bx.layout_of(value.ty()),
+ );
+ InlineAsmOperandRef::Const { string }
+ }
+ mir::InlineAsmOperand::SymFn { ref value } => {
+ let literal = self.monomorphize(value.literal);
+ if let ty::FnDef(def_id, substs) = *literal.ty().kind() {
+ let instance = ty::Instance::resolve_for_fn_ptr(
+ bx.tcx(),
+ ty::ParamEnv::reveal_all(),
+ def_id,
+ substs,
+ )
+ .unwrap();
+ InlineAsmOperandRef::SymFn { instance }
+ } else {
+ span_bug!(span, "invalid type for asm sym (fn)");
+ }
+ }
+ mir::InlineAsmOperand::SymStatic { def_id } => {
+ InlineAsmOperandRef::SymStatic { def_id }
+ }
+ })
+ .collect();
+
+ helper.do_inlineasm(
+ self,
+ &mut bx,
+ template,
+ &operands,
+ options,
+ line_spans,
+ destination,
+ cleanup,
+ instance,
+ );
+ }
+}
+
+impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
+ pub fn codegen_block(&mut self, bb: mir::BasicBlock) {
+ let llbb = self.llbb(bb);
+ let mut bx = Bx::build(self.cx, llbb);
+ let mir = self.mir;
+ let data = &mir[bb];
+
+ debug!("codegen_block({:?}={:?})", bb, data);
+
+ for statement in &data.statements {
+ bx = self.codegen_statement(bx, statement);
+ }
+
+ self.codegen_terminator(bx, bb, data.terminator());
+ }
+
+ fn codegen_terminator(
+ &mut self,
+ mut bx: Bx,
+ bb: mir::BasicBlock,
+ terminator: &'tcx mir::Terminator<'tcx>,
+ ) {
+ debug!("codegen_terminator: {:?}", terminator);
+
+ // Create the cleanup bundle, if needed.
+ let funclet_bb = self.cleanup_kinds[bb].funclet_bb(bb);
+ let helper = TerminatorCodegenHelper { bb, terminator, funclet_bb };
+
+ self.set_debug_loc(&mut bx, terminator.source_info);
+ match terminator.kind {
+ mir::TerminatorKind::Resume => self.codegen_resume_terminator(helper, bx),
+
+ mir::TerminatorKind::Abort => {
+ self.codegen_abort_terminator(helper, bx, terminator);
+ }
+
+ mir::TerminatorKind::Goto { target } => {
+ helper.funclet_br(self, &mut bx, target);
+ }
+
+ mir::TerminatorKind::SwitchInt { ref discr, switch_ty, ref targets } => {
+ self.codegen_switchint_terminator(helper, bx, discr, switch_ty, targets);
+ }
+
+ mir::TerminatorKind::Return => {
+ self.codegen_return_terminator(bx);
+ }
+
+ mir::TerminatorKind::Unreachable => {
+ bx.unreachable();
+ }
+
+ mir::TerminatorKind::Drop { place, target, unwind } => {
+ self.codegen_drop_terminator(helper, bx, place, target, unwind);
+ }
+
+ mir::TerminatorKind::Assert { ref cond, expected, ref msg, target, cleanup } => {
+ self.codegen_assert_terminator(
+ helper, bx, terminator, cond, expected, msg, target, cleanup,
+ );
+ }
+
+ mir::TerminatorKind::DropAndReplace { .. } => {
+ bug!("undesugared DropAndReplace in codegen: {:?}", terminator);
+ }
+
+ mir::TerminatorKind::Call {
+ ref func,
+ ref args,
+ destination,
+ target,
+ cleanup,
+ from_hir_call: _,
+ fn_span,
+ } => {
+ self.codegen_call_terminator(
+ helper,
+ bx,
+ terminator,
+ func,
+ args,
+ destination,
+ target,
+ cleanup,
+ fn_span,
+ );
+ }
+ mir::TerminatorKind::GeneratorDrop | mir::TerminatorKind::Yield { .. } => {
+ bug!("generator ops in codegen")
+ }
+ mir::TerminatorKind::FalseEdge { .. } | mir::TerminatorKind::FalseUnwind { .. } => {
+ bug!("borrowck false edges in codegen")
+ }
+
+ mir::TerminatorKind::InlineAsm {
+ template,
+ ref operands,
+ options,
+ line_spans,
+ destination,
+ cleanup,
+ } => {
+ self.codegen_asm_terminator(
+ helper,
+ bx,
+ terminator,
+ template,
+ operands,
+ options,
+ line_spans,
+ destination,
+ cleanup,
+ self.instance,
+ );
+ }
+ }
+ }
+
+ fn codegen_argument(
+ &mut self,
+ bx: &mut Bx,
+ op: OperandRef<'tcx, Bx::Value>,
+ llargs: &mut Vec<Bx::Value>,
+ arg: &ArgAbi<'tcx, Ty<'tcx>>,
+ ) {
+ // Fill padding with undef value, where applicable.
+ if let Some(ty) = arg.pad {
+ llargs.push(bx.const_undef(bx.reg_backend_type(&ty)))
+ }
+
+ if arg.is_ignore() {
+ return;
+ }
+
+ if let PassMode::Pair(..) = arg.mode {
+ match op.val {
+ Pair(a, b) => {
+ llargs.push(a);
+ llargs.push(b);
+ return;
+ }
+ _ => bug!("codegen_argument: {:?} invalid for pair argument", op),
+ }
+ } else if arg.is_unsized_indirect() {
+ match op.val {
+ Ref(a, Some(b), _) => {
+ llargs.push(a);
+ llargs.push(b);
+ return;
+ }
+ _ => bug!("codegen_argument: {:?} invalid for unsized indirect argument", op),
+ }
+ }
+
+ // Force by-ref if we have to load through a cast pointer.
+ let (mut llval, align, by_ref) = match op.val {
+ Immediate(_) | Pair(..) => match arg.mode {
+ PassMode::Indirect { .. } | PassMode::Cast(_) => {
+ let scratch = PlaceRef::alloca(bx, arg.layout);
+ op.val.store(bx, scratch);
+ (scratch.llval, scratch.align, true)
+ }
+ _ => (op.immediate_or_packed_pair(bx), arg.layout.align.abi, false),
+ },
+ Ref(llval, _, align) => {
+ if arg.is_indirect() && align < arg.layout.align.abi {
+ // `foo(packed.large_field)`. We can't pass the (unaligned) field directly. I
+ // think that ATM (Rust 1.16) we only pass temporaries, but we shouldn't
+ // have scary latent bugs around.
+
+ let scratch = PlaceRef::alloca(bx, arg.layout);
+ base::memcpy_ty(
+ bx,
+ scratch.llval,
+ scratch.align,
+ llval,
+ align,
+ op.layout,
+ MemFlags::empty(),
+ );
+ (scratch.llval, scratch.align, true)
+ } else {
+ (llval, align, true)
+ }
+ }
+ };
+
+ if by_ref && !arg.is_indirect() {
+ // Have to load the argument, maybe while casting it.
+ if let PassMode::Cast(ty) = arg.mode {
+ let llty = bx.cast_backend_type(&ty);
+ let addr = bx.pointercast(llval, bx.type_ptr_to(llty));
+ llval = bx.load(llty, addr, align.min(arg.layout.align.abi));
+ } else {
+ // We can't use `PlaceRef::load` here because the argument
+ // may have a type we don't treat as immediate, but the ABI
+ // used for this call is passing it by-value. In that case,
+ // the load would just produce `OperandValue::Ref` instead
+ // of the `OperandValue::Immediate` we need for the call.
+ llval = bx.load(bx.backend_type(arg.layout), llval, align);
+ if let abi::Abi::Scalar(scalar) = arg.layout.abi {
+ if scalar.is_bool() {
+ bx.range_metadata(llval, WrappingRange { start: 0, end: 1 });
+ }
+ }
+ // We store bools as `i8` so we need to truncate to `i1`.
+ llval = bx.to_immediate(llval, arg.layout);
+ }
+ }
+
+ llargs.push(llval);
+ }
+
+ fn codegen_arguments_untupled(
+ &mut self,
+ bx: &mut Bx,
+ operand: &mir::Operand<'tcx>,
+ llargs: &mut Vec<Bx::Value>,
+ args: &[ArgAbi<'tcx, Ty<'tcx>>],
+ ) -> usize {
+ let tuple = self.codegen_operand(bx, operand);
+
+ // Handle both by-ref and immediate tuples.
+ if let Ref(llval, None, align) = tuple.val {
+ let tuple_ptr = PlaceRef::new_sized_aligned(llval, tuple.layout, align);
+ for i in 0..tuple.layout.fields.count() {
+ let field_ptr = tuple_ptr.project_field(bx, i);
+ let field = bx.load_operand(field_ptr);
+ self.codegen_argument(bx, field, llargs, &args[i]);
+ }
+ } else if let Ref(_, Some(_), _) = tuple.val {
+ bug!("closure arguments must be sized")
+ } else {
+ // If the tuple is immediate, the elements are as well.
+ for i in 0..tuple.layout.fields.count() {
+ let op = tuple.extract_field(bx, i);
+ self.codegen_argument(bx, op, llargs, &args[i]);
+ }
+ }
+ tuple.layout.fields.count()
+ }
+
+ fn get_caller_location(
+ &mut self,
+ bx: &mut Bx,
+ mut source_info: mir::SourceInfo,
+ ) -> OperandRef<'tcx, Bx::Value> {
+ let tcx = bx.tcx();
+
+ let mut span_to_caller_location = |span: Span| {
+ 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((
+ Symbol::intern(&caller.file.name.prefer_remapped().to_string_lossy()),
+ caller.line as u32,
+ caller.col_display as u32 + 1,
+ ));
+ OperandRef::from_const(bx, const_loc, bx.tcx().caller_location_ty())
+ };
+
+ // Walk up the `SourceScope`s, in case some of them are from MIR inlining.
+ // If so, the starting `source_info.span` is in the innermost inlined
+ // function, and will be replaced with outer callsite spans as long
+ // as the inlined functions were `#[track_caller]`.
+ loop {
+ let scope_data = &self.mir.source_scopes[source_info.scope];
+
+ if let Some((callee, callsite_span)) = scope_data.inlined {
+ // Stop inside the most nested non-`#[track_caller]` function,
+ // before ever reaching its caller (which is irrelevant).
+ if !callee.def.requires_caller_location(tcx) {
+ return span_to_caller_location(source_info.span);
+ }
+ source_info.span = callsite_span;
+ }
+
+ // Skip past all of the parents with `inlined: None`.
+ match scope_data.inlined_parent_scope {
+ Some(parent) => source_info.scope = parent,
+ None => break,
+ }
+ }
+
+ // No inlined `SourceScope`s, or all of them were `#[track_caller]`.
+ self.caller_location.unwrap_or_else(|| span_to_caller_location(source_info.span))
+ }
+
+ fn get_personality_slot(&mut self, bx: &mut Bx) -> PlaceRef<'tcx, Bx::Value> {
+ let cx = bx.cx();
+ if let Some(slot) = self.personality_slot {
+ slot
+ } else {
+ let layout = cx.layout_of(
+ cx.tcx().intern_tup(&[cx.tcx().mk_mut_ptr(cx.tcx().types.u8), cx.tcx().types.i32]),
+ );
+ let slot = PlaceRef::alloca(bx, layout);
+ self.personality_slot = Some(slot);
+ slot
+ }
+ }
+
+ /// Returns the landing/cleanup pad wrapper around the given basic block.
+ // FIXME(eddyb) rename this to `eh_pad_for`.
+ fn landing_pad_for(&mut self, bb: mir::BasicBlock) -> Bx::BasicBlock {
+ if let Some(landing_pad) = self.landing_pads[bb] {
+ return landing_pad;
+ }
+
+ let landing_pad = self.landing_pad_for_uncached(bb);
+ self.landing_pads[bb] = Some(landing_pad);
+ landing_pad
+ }
+
+ // FIXME(eddyb) rename this to `eh_pad_for_uncached`.
+ 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_bb =
+ Bx::append_block(self.cx, self.llfn, &format!("cs_funclet{:?}", bb));
+ let cp_bb =
+ Bx::append_block(self.cx, self.llfn, &format!("cp_funclet{:?}", bb));
+ ret_llbb = cs_bb;
+
+ let mut cs_bx = Bx::build(self.cx, cs_bb);
+ let cs = cs_bx.catch_switch(None, None, &[cp_bb]);
+
+ // 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_bb);
+ 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_bb =
+ Bx::append_block(self.cx, self.llfn, &format!("funclet_{:?}", bb));
+ ret_llbb = cleanup_bb;
+ let mut cleanup_bx = Bx::build(self.cx, cleanup_bb);
+ funclet = cleanup_bx.cleanup_pad(None, &[]);
+ cleanup_bx.br(llbb);
+ }
+ }
+ self.funclets[bb] = Some(funclet);
+ ret_llbb
+ } else {
+ let bb = Bx::append_block(self.cx, self.llfn, "cleanup");
+ let mut bx = Bx::build(self.cx, bb);
+
+ let llpersonality = self.cx.eh_personality();
+ let llretty = self.landing_pad_type();
+ let lp = bx.cleanup_landing_pad(llretty, llpersonality);
+
+ let slot = self.get_personality_slot(&mut bx);
+ slot.storage_live(&mut bx);
+ Pair(bx.extract_value(lp, 0), bx.extract_value(lp, 1)).store(&mut bx, slot);
+
+ bx.br(llbb);
+ bx.llbb()
+ }
+ }
+
+ fn landing_pad_type(&self) -> Bx::Type {
+ let cx = self.cx;
+ cx.type_struct(&[cx.type_i8p(), cx.type_i32()], false)
+ }
+
+ fn unreachable_block(&mut self) -> Bx::BasicBlock {
+ self.unreachable_block.unwrap_or_else(|| {
+ let llbb = Bx::append_block(self.cx, self.llfn, "unreachable");
+ let mut bx = Bx::build(self.cx, llbb);
+ bx.unreachable();
+ self.unreachable_block = Some(llbb);
+ llbb
+ })
+ }
+
+ fn double_unwind_guard(&mut self) -> Bx::BasicBlock {
+ self.double_unwind_guard.unwrap_or_else(|| {
+ assert!(!base::wants_msvc_seh(self.cx.sess()));
+
+ 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();
+ let llretty = self.landing_pad_type();
+ bx.cleanup_landing_pad(llretty, llpersonality);
+
+ let (fn_abi, fn_ptr) = common::build_langcall(&bx, None, LangItem::PanicNoUnwind);
+ let fn_ty = bx.fn_decl_backend_type(&fn_abi);
+
+ let llret = bx.call(fn_ty, fn_ptr, &[], None);
+ bx.apply_attrs_callsite(&fn_abi, llret);
+ bx.do_not_inline(llret);
+
+ bx.unreachable();
+
+ self.double_unwind_guard = Some(llbb);
+ llbb
+ })
+ }
+
+ /// Get the backend `BasicBlock` for a MIR `BasicBlock`, either already
+ /// cached in `self.cached_llbbs`, or created on demand (and cached).
+ // FIXME(eddyb) rename `llbb` and other `ll`-prefixed things to use a
+ // more backend-agnostic prefix such as `cg` (i.e. this would be `cgbb`).
+ pub fn llbb(&mut self, bb: mir::BasicBlock) -> Bx::BasicBlock {
+ self.cached_llbbs[bb].unwrap_or_else(|| {
+ // FIXME(eddyb) only name the block if `fewer_names` is `false`.
+ let llbb = Bx::append_block(self.cx, self.llfn, &format!("{:?}", bb));
+ self.cached_llbbs[bb] = Some(llbb);
+ llbb
+ })
+ }
+
+ fn make_return_dest(
+ &mut self,
+ bx: &mut Bx,
+ dest: mir::Place<'tcx>,
+ fn_ret: &ArgAbi<'tcx, Ty<'tcx>>,
+ llargs: &mut Vec<Bx::Value>,
+ is_intrinsic: bool,
+ ) -> ReturnDest<'tcx, Bx::Value> {
+ // If the return is ignored, we can just return a do-nothing `ReturnDest`.
+ if fn_ret.is_ignore() {
+ return ReturnDest::Nothing;
+ }
+ let dest = if let Some(index) = dest.as_local() {
+ match self.locals[index] {
+ LocalRef::Place(dest) => dest,
+ LocalRef::UnsizedPlace(_) => bug!("return type must be sized"),
+ LocalRef::Operand(None) => {
+ // Handle temporary places, specifically `Operand` ones, as
+ // they don't have `alloca`s.
+ return if fn_ret.is_indirect() {
+ // Odd, but possible, case, we have an operand temporary,
+ // but the calling convention has an indirect return.
+ let tmp = PlaceRef::alloca(bx, fn_ret.layout);
+ tmp.storage_live(bx);
+ llargs.push(tmp.llval);
+ ReturnDest::IndirectOperand(tmp, index)
+ } else if is_intrinsic {
+ // Currently, intrinsics always need a location to store
+ // the result, so we create a temporary `alloca` for the
+ // result.
+ let tmp = PlaceRef::alloca(bx, fn_ret.layout);
+ tmp.storage_live(bx);
+ ReturnDest::IndirectOperand(tmp, index)
+ } else {
+ ReturnDest::DirectOperand(index)
+ };
+ }
+ LocalRef::Operand(Some(_)) => {
+ bug!("place local already assigned to");
+ }
+ }
+ } else {
+ self.codegen_place(
+ bx,
+ mir::PlaceRef { local: dest.local, projection: &dest.projection },
+ )
+ };
+ if fn_ret.is_indirect() {
+ if dest.align < dest.layout.align.abi {
+ // Currently, MIR code generation does not create calls
+ // that store directly to fields of packed structs (in
+ // fact, the calls it creates write only to temps).
+ //
+ // If someone changes that, please update this code path
+ // to create a temporary.
+ span_bug!(self.mir.span, "can't directly store to unaligned value");
+ }
+ llargs.push(dest.llval);
+ ReturnDest::Nothing
+ } else {
+ ReturnDest::Store(dest)
+ }
+ }
+
+ 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.
+ if (src_scalar.primitive() == abi::Pointer)
+ == (dst_scalar.primitive() == abi::Pointer)
+ {
+ 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());
+ let src_as_dst = 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,
+ bx: &mut Bx,
+ dest: ReturnDest<'tcx, Bx::Value>,
+ ret_abi: &ArgAbi<'tcx, Ty<'tcx>>,
+ llval: Bx::Value,
+ ) {
+ use self::ReturnDest::*;
+
+ match dest {
+ Nothing => (),
+ Store(dst) => bx.store_arg(&ret_abi, llval, dst),
+ IndirectOperand(tmp, index) => {
+ let op = bx.load_operand(tmp);
+ tmp.storage_dead(bx);
+ self.locals[index] = LocalRef::Operand(Some(op));
+ self.debug_introduce_local(bx, index);
+ }
+ DirectOperand(index) => {
+ // If there is a cast, we have to store and reload.
+ let op = if let PassMode::Cast(_) = ret_abi.mode {
+ let tmp = PlaceRef::alloca(bx, ret_abi.layout);
+ tmp.storage_live(bx);
+ bx.store_arg(&ret_abi, llval, tmp);
+ let op = bx.load_operand(tmp);
+ tmp.storage_dead(bx);
+ op
+ } else {
+ OperandRef::from_immediate_or_packed_pair(bx, llval, ret_abi.layout)
+ };
+ self.locals[index] = LocalRef::Operand(Some(op));
+ self.debug_introduce_local(bx, index);
+ }
+ }
+ }
+}
+
+enum ReturnDest<'tcx, V> {
+ // Do nothing; the return value is indirect or ignored.
+ Nothing,
+ // Store the return value to the pointer.
+ Store(PlaceRef<'tcx, V>),
+ // Store an indirect return value to an operand local place.
+ IndirectOperand(PlaceRef<'tcx, V>, mir::Local),
+ // Store a direct return value to an operand local place.
+ DirectOperand(mir::Local),
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-10 13:15:54 +0000