| // Copyright 2012-2016 The Rust Project Developers. See the COPYRIGHT |
| // file at the top-level directory of this distribution and at |
| // http://rust-lang.org/COPYRIGHT. |
| // |
| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| use llvm::{self, ValueRef, AttributePlace}; |
| use base; |
| use builder::Builder; |
| use common::{ty_fn_sig, C_usize}; |
| use context::CodegenCx; |
| use cabi_x86; |
| use cabi_x86_64; |
| use cabi_x86_win64; |
| use cabi_arm; |
| use cabi_aarch64; |
| use cabi_powerpc; |
| use cabi_powerpc64; |
| use cabi_s390x; |
| use cabi_mips; |
| use cabi_mips64; |
| use cabi_asmjs; |
| use cabi_msp430; |
| use cabi_sparc; |
| use cabi_sparc64; |
| use cabi_nvptx; |
| use cabi_nvptx64; |
| use cabi_hexagon; |
| use mir::place::PlaceRef; |
| use mir::operand::OperandValue; |
| use type_::Type; |
| use type_of::{LayoutLlvmExt, PointerKind}; |
| |
| use rustc::ty::{self, Ty}; |
| use rustc::ty::layout::{self, Align, Size, TyLayout}; |
| use rustc::ty::layout::{HasDataLayout, LayoutOf}; |
| |
| use libc::c_uint; |
| use std::{cmp, iter}; |
| |
| pub use syntax::abi::Abi; |
| pub use rustc::ty::layout::{FAT_PTR_ADDR, FAT_PTR_EXTRA}; |
| |
| #[derive(Clone, Copy, PartialEq, Eq, Debug)] |
| pub enum PassMode { |
| /// Ignore the argument (useful for empty struct). |
| Ignore, |
| /// Pass the argument directly. |
| Direct(ArgAttributes), |
| /// Pass a pair's elements directly in two arguments. |
| Pair(ArgAttributes, ArgAttributes), |
| /// Pass the argument after casting it, to either |
| /// a single uniform or a pair of registers. |
| Cast(CastTarget), |
| /// Pass the argument indirectly via a hidden pointer. |
| Indirect(ArgAttributes), |
| } |
| |
| // Hack to disable non_upper_case_globals only for the bitflags! and not for the rest |
| // of this module |
| pub use self::attr_impl::ArgAttribute; |
| |
| #[allow(non_upper_case_globals)] |
| #[allow(unused)] |
| mod attr_impl { |
| // The subset of llvm::Attribute needed for arguments, packed into a bitfield. |
| bitflags! { |
| #[derive(Default)] |
| pub struct ArgAttribute: u16 { |
| const ByVal = 1 << 0; |
| const NoAlias = 1 << 1; |
| const NoCapture = 1 << 2; |
| const NonNull = 1 << 3; |
| const ReadOnly = 1 << 4; |
| const SExt = 1 << 5; |
| const StructRet = 1 << 6; |
| const ZExt = 1 << 7; |
| const InReg = 1 << 8; |
| } |
| } |
| } |
| |
| macro_rules! for_each_kind { |
| ($flags: ident, $f: ident, $($kind: ident),+) => ({ |
| $(if $flags.contains(ArgAttribute::$kind) { $f(llvm::Attribute::$kind) })+ |
| }) |
| } |
| |
| impl ArgAttribute { |
| fn for_each_kind<F>(&self, mut f: F) where F: FnMut(llvm::Attribute) { |
| for_each_kind!(self, f, |
| ByVal, NoAlias, NoCapture, NonNull, ReadOnly, SExt, StructRet, ZExt, InReg) |
| } |
| } |
| |
| /// A compact representation of LLVM attributes (at least those relevant for this module) |
| /// that can be manipulated without interacting with LLVM's Attribute machinery. |
| #[derive(Copy, Clone, PartialEq, Eq, Debug)] |
| pub struct ArgAttributes { |
| regular: ArgAttribute, |
| pointee_size: Size, |
| pointee_align: Option<Align> |
| } |
| |
| impl ArgAttributes { |
| fn new() -> Self { |
| ArgAttributes { |
| regular: ArgAttribute::default(), |
| pointee_size: Size::from_bytes(0), |
| pointee_align: None, |
| } |
| } |
| |
| pub fn set(&mut self, attr: ArgAttribute) -> &mut Self { |
| self.regular = self.regular | attr; |
| self |
| } |
| |
| pub fn contains(&self, attr: ArgAttribute) -> bool { |
| self.regular.contains(attr) |
| } |
| |
| pub fn apply_llfn(&self, idx: AttributePlace, llfn: ValueRef) { |
| let mut regular = self.regular; |
| unsafe { |
| let deref = self.pointee_size.bytes(); |
| if deref != 0 { |
| if regular.contains(ArgAttribute::NonNull) { |
| llvm::LLVMRustAddDereferenceableAttr(llfn, |
| idx.as_uint(), |
| deref); |
| } else { |
| llvm::LLVMRustAddDereferenceableOrNullAttr(llfn, |
| idx.as_uint(), |
| deref); |
| } |
| regular -= ArgAttribute::NonNull; |
| } |
| if let Some(align) = self.pointee_align { |
| llvm::LLVMRustAddAlignmentAttr(llfn, |
| idx.as_uint(), |
| align.abi() as u32); |
| } |
| regular.for_each_kind(|attr| attr.apply_llfn(idx, llfn)); |
| } |
| } |
| |
| pub fn apply_callsite(&self, idx: AttributePlace, callsite: ValueRef) { |
| let mut regular = self.regular; |
| unsafe { |
| let deref = self.pointee_size.bytes(); |
| if deref != 0 { |
| if regular.contains(ArgAttribute::NonNull) { |
| llvm::LLVMRustAddDereferenceableCallSiteAttr(callsite, |
| idx.as_uint(), |
| deref); |
| } else { |
| llvm::LLVMRustAddDereferenceableOrNullCallSiteAttr(callsite, |
| idx.as_uint(), |
| deref); |
| } |
| regular -= ArgAttribute::NonNull; |
| } |
| if let Some(align) = self.pointee_align { |
| llvm::LLVMRustAddAlignmentCallSiteAttr(callsite, |
| idx.as_uint(), |
| align.abi() as u32); |
| } |
| regular.for_each_kind(|attr| attr.apply_callsite(idx, callsite)); |
| } |
| } |
| } |
| #[derive(Copy, Clone, PartialEq, Eq, Debug)] |
| pub enum RegKind { |
| Integer, |
| Float, |
| Vector |
| } |
| |
| #[derive(Copy, Clone, PartialEq, Eq, Debug)] |
| pub struct Reg { |
| pub kind: RegKind, |
| pub size: Size, |
| } |
| |
| macro_rules! reg_ctor { |
| ($name:ident, $kind:ident, $bits:expr) => { |
| pub fn $name() -> Reg { |
| Reg { |
| kind: RegKind::$kind, |
| size: Size::from_bits($bits) |
| } |
| } |
| } |
| } |
| |
| impl Reg { |
| reg_ctor!(i8, Integer, 8); |
| reg_ctor!(i16, Integer, 16); |
| reg_ctor!(i32, Integer, 32); |
| reg_ctor!(i64, Integer, 64); |
| |
| reg_ctor!(f32, Float, 32); |
| reg_ctor!(f64, Float, 64); |
| } |
| |
| impl Reg { |
| pub fn align(&self, cx: &CodegenCx) -> Align { |
| let dl = cx.data_layout(); |
| match self.kind { |
| RegKind::Integer => { |
| match self.size.bits() { |
| 1 => dl.i1_align, |
| 2...8 => dl.i8_align, |
| 9...16 => dl.i16_align, |
| 17...32 => dl.i32_align, |
| 33...64 => dl.i64_align, |
| 65...128 => dl.i128_align, |
| _ => bug!("unsupported integer: {:?}", self) |
| } |
| } |
| RegKind::Float => { |
| match self.size.bits() { |
| 32 => dl.f32_align, |
| 64 => dl.f64_align, |
| _ => bug!("unsupported float: {:?}", self) |
| } |
| } |
| RegKind::Vector => dl.vector_align(self.size) |
| } |
| } |
| |
| pub fn llvm_type(&self, cx: &CodegenCx) -> Type { |
| match self.kind { |
| RegKind::Integer => Type::ix(cx, self.size.bits()), |
| RegKind::Float => { |
| match self.size.bits() { |
| 32 => Type::f32(cx), |
| 64 => Type::f64(cx), |
| _ => bug!("unsupported float: {:?}", self) |
| } |
| } |
| RegKind::Vector => { |
| Type::vector(&Type::i8(cx), self.size.bytes()) |
| } |
| } |
| } |
| } |
| |
| /// An argument passed entirely registers with the |
| /// same kind (e.g. HFA / HVA on PPC64 and AArch64). |
| #[derive(Clone, Copy, PartialEq, Eq, Debug)] |
| pub struct Uniform { |
| pub unit: Reg, |
| |
| /// The total size of the argument, which can be: |
| /// * equal to `unit.size` (one scalar/vector) |
| /// * a multiple of `unit.size` (an array of scalar/vectors) |
| /// * if `unit.kind` is `Integer`, the last element |
| /// can be shorter, i.e. `{ i64, i64, i32 }` for |
| /// 64-bit integers with a total size of 20 bytes |
| pub total: Size, |
| } |
| |
| impl From<Reg> for Uniform { |
| fn from(unit: Reg) -> Uniform { |
| Uniform { |
| unit, |
| total: unit.size |
| } |
| } |
| } |
| |
| impl Uniform { |
| pub fn align(&self, cx: &CodegenCx) -> Align { |
| self.unit.align(cx) |
| } |
| |
| pub fn llvm_type(&self, cx: &CodegenCx) -> Type { |
| let llunit = self.unit.llvm_type(cx); |
| |
| if self.total <= self.unit.size { |
| return llunit; |
| } |
| |
| let count = self.total.bytes() / self.unit.size.bytes(); |
| let rem_bytes = self.total.bytes() % self.unit.size.bytes(); |
| |
| if rem_bytes == 0 { |
| return Type::array(&llunit, count); |
| } |
| |
| // Only integers can be really split further. |
| assert_eq!(self.unit.kind, RegKind::Integer); |
| |
| let args: Vec<_> = (0..count).map(|_| llunit) |
| .chain(iter::once(Type::ix(cx, rem_bytes * 8))) |
| .collect(); |
| |
| Type::struct_(cx, &args, false) |
| } |
| } |
| |
| pub trait LayoutExt<'tcx> { |
| fn is_aggregate(&self) -> bool; |
| fn homogeneous_aggregate<'a>(&self, cx: &CodegenCx<'a, 'tcx>) -> Option<Reg>; |
| } |
| |
| impl<'tcx> LayoutExt<'tcx> for TyLayout<'tcx> { |
| fn is_aggregate(&self) -> bool { |
| match self.abi { |
| layout::Abi::Uninhabited | |
| layout::Abi::Scalar(_) | |
| layout::Abi::Vector { .. } => false, |
| layout::Abi::ScalarPair(..) | |
| layout::Abi::Aggregate { .. } => true |
| } |
| } |
| |
| fn homogeneous_aggregate<'a>(&self, cx: &CodegenCx<'a, 'tcx>) -> Option<Reg> { |
| match self.abi { |
| layout::Abi::Uninhabited => None, |
| |
| // The primitive for this algorithm. |
| layout::Abi::Scalar(ref scalar) => { |
| let kind = match scalar.value { |
| layout::Int(..) | |
| layout::Pointer => RegKind::Integer, |
| layout::F32 | |
| layout::F64 => RegKind::Float |
| }; |
| Some(Reg { |
| kind, |
| size: self.size |
| }) |
| } |
| |
| layout::Abi::Vector { .. } => { |
| Some(Reg { |
| kind: RegKind::Vector, |
| size: self.size |
| }) |
| } |
| |
| layout::Abi::ScalarPair(..) | |
| layout::Abi::Aggregate { .. } => { |
| let mut total = Size::from_bytes(0); |
| let mut result = None; |
| |
| let is_union = match self.fields { |
| layout::FieldPlacement::Array { count, .. } => { |
| if count > 0 { |
| return self.field(cx, 0).homogeneous_aggregate(cx); |
| } else { |
| return None; |
| } |
| } |
| layout::FieldPlacement::Union(_) => true, |
| layout::FieldPlacement::Arbitrary { .. } => false |
| }; |
| |
| for i in 0..self.fields.count() { |
| if !is_union && total != self.fields.offset(i) { |
| return None; |
| } |
| |
| let field = self.field(cx, i); |
| match (result, field.homogeneous_aggregate(cx)) { |
| // The field itself must be a homogeneous aggregate. |
| (_, None) => return None, |
| // If this is the first field, record the unit. |
| (None, Some(unit)) => { |
| result = Some(unit); |
| } |
| // For all following fields, the unit must be the same. |
| (Some(prev_unit), Some(unit)) => { |
| if prev_unit != unit { |
| return None; |
| } |
| } |
| } |
| |
| // Keep track of the offset (without padding). |
| let size = field.size; |
| if is_union { |
| total = cmp::max(total, size); |
| } else { |
| total += size; |
| } |
| } |
| |
| // There needs to be no padding. |
| if total != self.size { |
| None |
| } else { |
| result |
| } |
| } |
| } |
| } |
| } |
| |
| #[derive(Clone, Copy, PartialEq, Eq, Debug)] |
| pub enum CastTarget { |
| Uniform(Uniform), |
| Pair(Reg, Reg) |
| } |
| |
| impl From<Reg> for CastTarget { |
| fn from(unit: Reg) -> CastTarget { |
| CastTarget::Uniform(Uniform::from(unit)) |
| } |
| } |
| |
| impl From<Uniform> for CastTarget { |
| fn from(uniform: Uniform) -> CastTarget { |
| CastTarget::Uniform(uniform) |
| } |
| } |
| |
| impl CastTarget { |
| pub fn size(&self, cx: &CodegenCx) -> Size { |
| match *self { |
| CastTarget::Uniform(u) => u.total, |
| CastTarget::Pair(a, b) => { |
| (a.size.abi_align(a.align(cx)) + b.size) |
| .abi_align(self.align(cx)) |
| } |
| } |
| } |
| |
| pub fn align(&self, cx: &CodegenCx) -> Align { |
| match *self { |
| CastTarget::Uniform(u) => u.align(cx), |
| CastTarget::Pair(a, b) => { |
| cx.data_layout().aggregate_align |
| .max(a.align(cx)) |
| .max(b.align(cx)) |
| } |
| } |
| } |
| |
| pub fn llvm_type(&self, cx: &CodegenCx) -> Type { |
| match *self { |
| CastTarget::Uniform(u) => u.llvm_type(cx), |
| CastTarget::Pair(a, b) => { |
| Type::struct_(cx, &[ |
| a.llvm_type(cx), |
| b.llvm_type(cx) |
| ], false) |
| } |
| } |
| } |
| } |
| |
| /// Information about how to pass an argument to, |
| /// or return a value from, a function, under some ABI. |
| #[derive(Debug)] |
| pub struct ArgType<'tcx> { |
| pub layout: TyLayout<'tcx>, |
| |
| /// Dummy argument, which is emitted before the real argument. |
| pub pad: Option<Reg>, |
| |
| pub mode: PassMode, |
| } |
| |
| impl<'a, 'tcx> ArgType<'tcx> { |
| fn new(layout: TyLayout<'tcx>) -> ArgType<'tcx> { |
| ArgType { |
| layout, |
| pad: None, |
| mode: PassMode::Direct(ArgAttributes::new()), |
| } |
| } |
| |
| pub fn make_indirect(&mut self) { |
| assert_eq!(self.mode, PassMode::Direct(ArgAttributes::new())); |
| |
| // Start with fresh attributes for the pointer. |
| let mut attrs = ArgAttributes::new(); |
| |
| // For non-immediate arguments the callee gets its own copy of |
| // the value on the stack, so there are no aliases. It's also |
| // program-invisible so can't possibly capture |
| attrs.set(ArgAttribute::NoAlias) |
| .set(ArgAttribute::NoCapture) |
| .set(ArgAttribute::NonNull); |
| attrs.pointee_size = self.layout.size; |
| // FIXME(eddyb) We should be doing this, but at least on |
| // i686-pc-windows-msvc, it results in wrong stack offsets. |
| // attrs.pointee_align = Some(self.layout.align); |
| |
| self.mode = PassMode::Indirect(attrs); |
| } |
| |
| pub fn make_indirect_byval(&mut self) { |
| self.make_indirect(); |
| match self.mode { |
| PassMode::Indirect(ref mut attrs) => { |
| attrs.set(ArgAttribute::ByVal); |
| } |
| _ => bug!() |
| } |
| } |
| |
| pub fn extend_integer_width_to(&mut self, bits: u64) { |
| // Only integers have signedness |
| if let layout::Abi::Scalar(ref scalar) = self.layout.abi { |
| if let layout::Int(i, signed) = scalar.value { |
| if i.size().bits() < bits { |
| if let PassMode::Direct(ref mut attrs) = self.mode { |
| attrs.set(if signed { |
| ArgAttribute::SExt |
| } else { |
| ArgAttribute::ZExt |
| }); |
| } |
| } |
| } |
| } |
| } |
| |
| pub fn cast_to<T: Into<CastTarget>>(&mut self, target: T) { |
| assert_eq!(self.mode, PassMode::Direct(ArgAttributes::new())); |
| self.mode = PassMode::Cast(target.into()); |
| } |
| |
| pub fn pad_with(&mut self, reg: Reg) { |
| self.pad = Some(reg); |
| } |
| |
| pub fn is_indirect(&self) -> bool { |
| match self.mode { |
| PassMode::Indirect(_) => true, |
| _ => false |
| } |
| } |
| |
| pub fn is_ignore(&self) -> bool { |
| self.mode == PassMode::Ignore |
| } |
| |
| /// Get the LLVM type for an place of the original Rust type of |
| /// this argument/return, i.e. the result of `type_of::type_of`. |
| pub fn memory_ty(&self, cx: &CodegenCx<'a, 'tcx>) -> Type { |
| self.layout.llvm_type(cx) |
| } |
| |
| /// Store a direct/indirect value described by this ArgType into a |
| /// place for the original Rust type of this argument/return. |
| /// Can be used for both storing formal arguments into Rust variables |
| /// or results of call/invoke instructions into their destinations. |
| pub fn store(&self, bx: &Builder<'a, 'tcx>, val: ValueRef, dst: PlaceRef<'tcx>) { |
| if self.is_ignore() { |
| return; |
| } |
| let cx = bx.cx; |
| if self.is_indirect() { |
| OperandValue::Ref(val, self.layout.align).store(bx, dst) |
| } else if let PassMode::Cast(cast) = self.mode { |
| // FIXME(eddyb): Figure out when the simpler Store is safe, clang |
| // uses it for i16 -> {i8, i8}, but not for i24 -> {i8, i8, i8}. |
| let can_store_through_cast_ptr = false; |
| if can_store_through_cast_ptr { |
| let cast_dst = bx.pointercast(dst.llval, cast.llvm_type(cx).ptr_to()); |
| bx.store(val, cast_dst, self.layout.align); |
| } else { |
| // The actual return type is a struct, but the ABI |
| // adaptation code has cast it into some scalar type. The |
| // code that follows is the only reliable way I have |
| // found to do a transform like i64 -> {i32,i32}. |
| // Basically we dump the data onto the stack then memcpy it. |
| // |
| // Other approaches I tried: |
| // - Casting rust ret pointer to the foreign type and using Store |
| // is (a) unsafe if size of foreign type > size of rust type and |
| // (b) runs afoul of strict aliasing rules, yielding invalid |
| // assembly under -O (specifically, the store gets removed). |
| // - Truncating foreign type to correct integral type and then |
| // bitcasting to the struct type yields invalid cast errors. |
| |
| // We instead thus allocate some scratch space... |
| let scratch_size = cast.size(cx); |
| let scratch_align = cast.align(cx); |
| let llscratch = bx.alloca(cast.llvm_type(cx), "abi_cast", scratch_align); |
| bx.lifetime_start(llscratch, scratch_size); |
| |
| // ...where we first store the value... |
| bx.store(val, llscratch, scratch_align); |
| |
| // ...and then memcpy it to the intended destination. |
| base::call_memcpy(bx, |
| bx.pointercast(dst.llval, Type::i8p(cx)), |
| bx.pointercast(llscratch, Type::i8p(cx)), |
| C_usize(cx, self.layout.size.bytes()), |
| self.layout.align.min(scratch_align)); |
| |
| bx.lifetime_end(llscratch, scratch_size); |
| } |
| } else { |
| OperandValue::Immediate(val).store(bx, dst); |
| } |
| } |
| |
| pub fn store_fn_arg(&self, bx: &Builder<'a, 'tcx>, idx: &mut usize, dst: PlaceRef<'tcx>) { |
| if self.pad.is_some() { |
| *idx += 1; |
| } |
| let mut next = || { |
| let val = llvm::get_param(bx.llfn(), *idx as c_uint); |
| *idx += 1; |
| val |
| }; |
| match self.mode { |
| PassMode::Ignore => {}, |
| PassMode::Pair(..) => { |
| OperandValue::Pair(next(), next()).store(bx, dst); |
| } |
| PassMode::Direct(_) | PassMode::Indirect(_) | PassMode::Cast(_) => { |
| self.store(bx, next(), dst); |
| } |
| } |
| } |
| } |
| |
| /// Metadata describing how the arguments to a native function |
| /// should be passed in order to respect the native ABI. |
| /// |
| /// I will do my best to describe this structure, but these |
| /// comments are reverse-engineered and may be inaccurate. -NDM |
| #[derive(Debug)] |
| pub struct FnType<'tcx> { |
| /// The LLVM types of each argument. |
| pub args: Vec<ArgType<'tcx>>, |
| |
| /// LLVM return type. |
| pub ret: ArgType<'tcx>, |
| |
| pub variadic: bool, |
| |
| pub cconv: llvm::CallConv |
| } |
| |
| impl<'a, 'tcx> FnType<'tcx> { |
| pub fn of_instance(cx: &CodegenCx<'a, 'tcx>, instance: &ty::Instance<'tcx>) |
| -> Self { |
| let fn_ty = instance.ty(cx.tcx); |
| let sig = ty_fn_sig(cx, fn_ty); |
| let sig = cx.tcx.erase_late_bound_regions_and_normalize(&sig); |
| FnType::new(cx, sig, &[]) |
| } |
| |
| pub fn new(cx: &CodegenCx<'a, 'tcx>, |
| sig: ty::FnSig<'tcx>, |
| extra_args: &[Ty<'tcx>]) -> FnType<'tcx> { |
| let mut fn_ty = FnType::unadjusted(cx, sig, extra_args); |
| fn_ty.adjust_for_abi(cx, sig.abi); |
| fn_ty |
| } |
| |
| pub fn new_vtable(cx: &CodegenCx<'a, 'tcx>, |
| sig: ty::FnSig<'tcx>, |
| extra_args: &[Ty<'tcx>]) -> FnType<'tcx> { |
| let mut fn_ty = FnType::unadjusted(cx, sig, extra_args); |
| // Don't pass the vtable, it's not an argument of the virtual fn. |
| { |
| let self_arg = &mut fn_ty.args[0]; |
| match self_arg.mode { |
| PassMode::Pair(data_ptr, _) => { |
| self_arg.mode = PassMode::Direct(data_ptr); |
| } |
| _ => bug!("FnType::new_vtable: non-pair self {:?}", self_arg) |
| } |
| |
| let pointee = self_arg.layout.ty.builtin_deref(true, ty::NoPreference) |
| .unwrap_or_else(|| { |
| bug!("FnType::new_vtable: non-pointer self {:?}", self_arg) |
| }).ty; |
| let fat_ptr_ty = cx.tcx.mk_mut_ptr(pointee); |
| self_arg.layout = cx.layout_of(fat_ptr_ty).field(cx, 0); |
| } |
| fn_ty.adjust_for_abi(cx, sig.abi); |
| fn_ty |
| } |
| |
| pub fn unadjusted(cx: &CodegenCx<'a, 'tcx>, |
| sig: ty::FnSig<'tcx>, |
| extra_args: &[Ty<'tcx>]) -> FnType<'tcx> { |
| debug!("FnType::unadjusted({:?}, {:?})", sig, extra_args); |
| |
| use self::Abi::*; |
| let cconv = match cx.sess().target.target.adjust_abi(sig.abi) { |
| RustIntrinsic | PlatformIntrinsic | |
| Rust | RustCall => llvm::CCallConv, |
| |
| // It's the ABI's job to select this, not us. |
| System => bug!("system abi should be selected elsewhere"), |
| |
| Stdcall => llvm::X86StdcallCallConv, |
| Fastcall => llvm::X86FastcallCallConv, |
| Vectorcall => llvm::X86_VectorCall, |
| Thiscall => llvm::X86_ThisCall, |
| C => llvm::CCallConv, |
| Unadjusted => llvm::CCallConv, |
| Win64 => llvm::X86_64_Win64, |
| SysV64 => llvm::X86_64_SysV, |
| Aapcs => llvm::ArmAapcsCallConv, |
| PtxKernel => llvm::PtxKernel, |
| Msp430Interrupt => llvm::Msp430Intr, |
| X86Interrupt => llvm::X86_Intr, |
| |
| // These API constants ought to be more specific... |
| Cdecl => llvm::CCallConv, |
| }; |
| |
| let mut inputs = sig.inputs(); |
| let extra_args = if sig.abi == RustCall { |
| assert!(!sig.variadic && extra_args.is_empty()); |
| |
| match sig.inputs().last().unwrap().sty { |
| ty::TyTuple(ref tupled_arguments, _) => { |
| inputs = &sig.inputs()[0..sig.inputs().len() - 1]; |
| tupled_arguments |
| } |
| _ => { |
| bug!("argument to function with \"rust-call\" ABI \ |
| is not a tuple"); |
| } |
| } |
| } else { |
| assert!(sig.variadic || extra_args.is_empty()); |
| extra_args |
| }; |
| |
| let target = &cx.sess().target.target; |
| let win_x64_gnu = target.target_os == "windows" |
| && target.arch == "x86_64" |
| && target.target_env == "gnu"; |
| let linux_s390x = target.target_os == "linux" |
| && target.arch == "s390x" |
| && target.target_env == "gnu"; |
| let rust_abi = match sig.abi { |
| RustIntrinsic | PlatformIntrinsic | Rust | RustCall => true, |
| _ => false |
| }; |
| |
| // Handle safe Rust thin and fat pointers. |
| let adjust_for_rust_scalar = |attrs: &mut ArgAttributes, |
| scalar: &layout::Scalar, |
| layout: TyLayout<'tcx>, |
| offset: Size, |
| is_return: bool| { |
| // Booleans are always an i1 that needs to be zero-extended. |
| if scalar.is_bool() { |
| attrs.set(ArgAttribute::ZExt); |
| return; |
| } |
| |
| // Only pointer types handled below. |
| if scalar.value != layout::Pointer { |
| return; |
| } |
| |
| if scalar.valid_range.start < scalar.valid_range.end { |
| if scalar.valid_range.start > 0 { |
| attrs.set(ArgAttribute::NonNull); |
| } |
| } |
| |
| if let Some(pointee) = layout.pointee_info_at(cx, offset) { |
| if let Some(kind) = pointee.safe { |
| attrs.pointee_size = pointee.size; |
| attrs.pointee_align = Some(pointee.align); |
| |
| // HACK(eddyb) LLVM inserts `llvm.assume` calls when inlining functions |
| // with align attributes, and those calls later block optimizations. |
| if !is_return { |
| attrs.pointee_align = None; |
| } |
| |
| // `Box` pointer parameters never alias because ownership is transferred |
| // `&mut` pointer parameters never alias other parameters, |
| // or mutable global data |
| // |
| // `&T` where `T` contains no `UnsafeCell<U>` is immutable, |
| // and can be marked as both `readonly` and `noalias`, as |
| // LLVM's definition of `noalias` is based solely on memory |
| // dependencies rather than pointer equality |
| let no_alias = match kind { |
| PointerKind::Shared => false, |
| PointerKind::UniqueOwned => true, |
| PointerKind::Frozen | |
| PointerKind::UniqueBorrowed => !is_return |
| }; |
| if no_alias { |
| attrs.set(ArgAttribute::NoAlias); |
| } |
| |
| if kind == PointerKind::Frozen && !is_return { |
| attrs.set(ArgAttribute::ReadOnly); |
| } |
| } |
| } |
| }; |
| |
| let arg_of = |ty: Ty<'tcx>, is_return: bool| { |
| let mut arg = ArgType::new(cx.layout_of(ty)); |
| if arg.layout.is_zst() { |
| // For some forsaken reason, x86_64-pc-windows-gnu |
| // doesn't ignore zero-sized struct arguments. |
| // The same is true for s390x-unknown-linux-gnu. |
| if is_return || rust_abi || (!win_x64_gnu && !linux_s390x) { |
| arg.mode = PassMode::Ignore; |
| } |
| } |
| |
| // FIXME(eddyb) other ABIs don't have logic for scalar pairs. |
| if !is_return && rust_abi { |
| if let layout::Abi::ScalarPair(ref a, ref b) = arg.layout.abi { |
| let mut a_attrs = ArgAttributes::new(); |
| let mut b_attrs = ArgAttributes::new(); |
| adjust_for_rust_scalar(&mut a_attrs, |
| a, |
| arg.layout, |
| Size::from_bytes(0), |
| false); |
| adjust_for_rust_scalar(&mut b_attrs, |
| b, |
| arg.layout, |
| a.value.size(cx).abi_align(b.value.align(cx)), |
| false); |
| arg.mode = PassMode::Pair(a_attrs, b_attrs); |
| return arg; |
| } |
| } |
| |
| if let layout::Abi::Scalar(ref scalar) = arg.layout.abi { |
| if let PassMode::Direct(ref mut attrs) = arg.mode { |
| adjust_for_rust_scalar(attrs, |
| scalar, |
| arg.layout, |
| Size::from_bytes(0), |
| is_return); |
| } |
| } |
| |
| arg |
| }; |
| |
| FnType { |
| ret: arg_of(sig.output(), true), |
| args: inputs.iter().chain(extra_args.iter()).map(|ty| { |
| arg_of(ty, false) |
| }).collect(), |
| variadic: sig.variadic, |
| cconv, |
| } |
| } |
| |
| fn adjust_for_abi(&mut self, |
| cx: &CodegenCx<'a, 'tcx>, |
| abi: Abi) { |
| if abi == Abi::Unadjusted { return } |
| |
| if abi == Abi::Rust || abi == Abi::RustCall || |
| abi == Abi::RustIntrinsic || abi == Abi::PlatformIntrinsic { |
| let fixup = |arg: &mut ArgType<'tcx>| { |
| if arg.is_ignore() { return; } |
| |
| match arg.layout.abi { |
| layout::Abi::Aggregate { .. } => {} |
| _ => return |
| } |
| |
| let size = arg.layout.size; |
| if size > layout::Pointer.size(cx) { |
| arg.make_indirect(); |
| } else { |
| // We want to pass small aggregates as immediates, but using |
| // a LLVM aggregate type for this leads to bad optimizations, |
| // so we pick an appropriately sized integer type instead. |
| arg.cast_to(Reg { |
| kind: RegKind::Integer, |
| size |
| }); |
| } |
| }; |
| fixup(&mut self.ret); |
| for arg in &mut self.args { |
| fixup(arg); |
| } |
| if let PassMode::Indirect(ref mut attrs) = self.ret.mode { |
| attrs.set(ArgAttribute::StructRet); |
| } |
| return; |
| } |
| |
| match &cx.sess().target.target.arch[..] { |
| "x86" => { |
| let flavor = if abi == Abi::Fastcall { |
| cabi_x86::Flavor::Fastcall |
| } else { |
| cabi_x86::Flavor::General |
| }; |
| cabi_x86::compute_abi_info(cx, self, flavor); |
| }, |
| "x86_64" => if abi == Abi::SysV64 { |
| cabi_x86_64::compute_abi_info(cx, self); |
| } else if abi == Abi::Win64 || cx.sess().target.target.options.is_like_windows { |
| cabi_x86_win64::compute_abi_info(self); |
| } else { |
| cabi_x86_64::compute_abi_info(cx, self); |
| }, |
| "aarch64" => cabi_aarch64::compute_abi_info(cx, self), |
| "arm" => cabi_arm::compute_abi_info(cx, self), |
| "mips" => cabi_mips::compute_abi_info(cx, self), |
| "mips64" => cabi_mips64::compute_abi_info(cx, self), |
| "powerpc" => cabi_powerpc::compute_abi_info(cx, self), |
| "powerpc64" => cabi_powerpc64::compute_abi_info(cx, self), |
| "s390x" => cabi_s390x::compute_abi_info(cx, self), |
| "asmjs" => cabi_asmjs::compute_abi_info(cx, self), |
| "wasm32" => cabi_asmjs::compute_abi_info(cx, self), |
| "msp430" => cabi_msp430::compute_abi_info(self), |
| "sparc" => cabi_sparc::compute_abi_info(cx, self), |
| "sparc64" => cabi_sparc64::compute_abi_info(cx, self), |
| "nvptx" => cabi_nvptx::compute_abi_info(self), |
| "nvptx64" => cabi_nvptx64::compute_abi_info(self), |
| "hexagon" => cabi_hexagon::compute_abi_info(self), |
| a => cx.sess().fatal(&format!("unrecognized arch \"{}\" in target specification", a)) |
| } |
| |
| if let PassMode::Indirect(ref mut attrs) = self.ret.mode { |
| attrs.set(ArgAttribute::StructRet); |
| } |
| } |
| |
| pub fn llvm_type(&self, cx: &CodegenCx<'a, 'tcx>) -> Type { |
| let mut llargument_tys = Vec::new(); |
| |
| let llreturn_ty = match self.ret.mode { |
| PassMode::Ignore => Type::void(cx), |
| PassMode::Direct(_) | PassMode::Pair(..) => { |
| self.ret.layout.immediate_llvm_type(cx) |
| } |
| PassMode::Cast(cast) => cast.llvm_type(cx), |
| PassMode::Indirect(_) => { |
| llargument_tys.push(self.ret.memory_ty(cx).ptr_to()); |
| Type::void(cx) |
| } |
| }; |
| |
| for arg in &self.args { |
| // add padding |
| if let Some(ty) = arg.pad { |
| llargument_tys.push(ty.llvm_type(cx)); |
| } |
| |
| let llarg_ty = match arg.mode { |
| PassMode::Ignore => continue, |
| PassMode::Direct(_) => arg.layout.immediate_llvm_type(cx), |
| PassMode::Pair(..) => { |
| llargument_tys.push(arg.layout.scalar_pair_element_llvm_type(cx, 0)); |
| llargument_tys.push(arg.layout.scalar_pair_element_llvm_type(cx, 1)); |
| continue; |
| } |
| PassMode::Cast(cast) => cast.llvm_type(cx), |
| PassMode::Indirect(_) => arg.memory_ty(cx).ptr_to(), |
| }; |
| llargument_tys.push(llarg_ty); |
| } |
| |
| if self.variadic { |
| Type::variadic_func(&llargument_tys, &llreturn_ty) |
| } else { |
| Type::func(&llargument_tys, &llreturn_ty) |
| } |
| } |
| |
| pub fn apply_attrs_llfn(&self, llfn: ValueRef) { |
| let mut i = 0; |
| let mut apply = |attrs: &ArgAttributes| { |
| attrs.apply_llfn(llvm::AttributePlace::Argument(i), llfn); |
| i += 1; |
| }; |
| match self.ret.mode { |
| PassMode::Direct(ref attrs) => { |
| attrs.apply_llfn(llvm::AttributePlace::ReturnValue, llfn); |
| } |
| PassMode::Indirect(ref attrs) => apply(attrs), |
| _ => {} |
| } |
| for arg in &self.args { |
| if arg.pad.is_some() { |
| apply(&ArgAttributes::new()); |
| } |
| match arg.mode { |
| PassMode::Ignore => {} |
| PassMode::Direct(ref attrs) | |
| PassMode::Indirect(ref attrs) => apply(attrs), |
| PassMode::Pair(ref a, ref b) => { |
| apply(a); |
| apply(b); |
| } |
| PassMode::Cast(_) => apply(&ArgAttributes::new()), |
| } |
| } |
| } |
| |
| pub fn apply_attrs_callsite(&self, callsite: ValueRef) { |
| let mut i = 0; |
| let mut apply = |attrs: &ArgAttributes| { |
| attrs.apply_callsite(llvm::AttributePlace::Argument(i), callsite); |
| i += 1; |
| }; |
| match self.ret.mode { |
| PassMode::Direct(ref attrs) => { |
| attrs.apply_callsite(llvm::AttributePlace::ReturnValue, callsite); |
| } |
| PassMode::Indirect(ref attrs) => apply(attrs), |
| _ => {} |
| } |
| for arg in &self.args { |
| if arg.pad.is_some() { |
| apply(&ArgAttributes::new()); |
| } |
| match arg.mode { |
| PassMode::Ignore => {} |
| PassMode::Direct(ref attrs) | |
| PassMode::Indirect(ref attrs) => apply(attrs), |
| PassMode::Pair(ref a, ref b) => { |
| apply(a); |
| apply(b); |
| } |
| PassMode::Cast(_) => apply(&ArgAttributes::new()), |
| } |
| } |
| |
| if self.cconv != llvm::CCallConv { |
| llvm::SetInstructionCallConv(callsite, self.cconv); |
| } |
| } |
| } |