| // 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::{instance_ty, ty_fn_sig, type_is_fat_ptr, C_usize}; |
| use context::CrateContext; |
| 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 machine::llalign_of_min; |
| use type_::Type; |
| use type_of; |
| |
| use rustc::hir; |
| use rustc::ty::{self, Ty}; |
| use rustc::ty::layout::{self, Layout, LayoutTyper, TyLayout, Size}; |
| use rustc_back::PanicStrategy; |
| |
| use libc::c_uint; |
| use std::cmp; |
| use std::iter; |
| |
| pub use syntax::abi::Abi; |
| pub use rustc::ty::layout::{FAT_PTR_ADDR, FAT_PTR_EXTRA}; |
| |
| #[derive(Clone, Copy, PartialEq, Debug)] |
| enum ArgKind { |
| /// Pass the argument directly using the normal converted |
| /// LLVM type or by coercing to another specified type |
| Direct, |
| /// Pass the argument indirectly via a hidden pointer |
| Indirect, |
| /// Ignore the argument (useful for empty struct) |
| Ignore, |
| } |
| |
| // 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, Debug, Default)] |
| pub struct ArgAttributes { |
| regular: ArgAttribute, |
| dereferenceable_bytes: u64, |
| } |
| |
| impl ArgAttributes { |
| pub fn set(&mut self, attr: ArgAttribute) -> &mut Self { |
| self.regular = self.regular | attr; |
| self |
| } |
| |
| pub fn set_dereferenceable(&mut self, bytes: u64) -> &mut Self { |
| self.dereferenceable_bytes = bytes; |
| self |
| } |
| |
| pub fn contains(&self, attr: ArgAttribute) -> bool { |
| self.regular.contains(attr) |
| } |
| |
| pub fn apply_llfn(&self, idx: AttributePlace, llfn: ValueRef) { |
| unsafe { |
| self.regular.for_each_kind(|attr| attr.apply_llfn(idx, llfn)); |
| if self.dereferenceable_bytes != 0 { |
| llvm::LLVMRustAddDereferenceableAttr(llfn, |
| idx.as_uint(), |
| self.dereferenceable_bytes); |
| } |
| } |
| } |
| |
| pub fn apply_callsite(&self, idx: AttributePlace, callsite: ValueRef) { |
| unsafe { |
| self.regular.for_each_kind(|attr| attr.apply_callsite(idx, callsite)); |
| if self.dereferenceable_bytes != 0 { |
| llvm::LLVMRustAddDereferenceableCallSiteAttr(callsite, |
| idx.as_uint(), |
| self.dereferenceable_bytes); |
| } |
| } |
| } |
| } |
| #[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 { |
| fn llvm_type(&self, ccx: &CrateContext) -> Type { |
| match self.kind { |
| RegKind::Integer => Type::ix(ccx, self.size.bits()), |
| RegKind::Float => { |
| match self.size.bits() { |
| 32 => Type::f32(ccx), |
| 64 => Type::f64(ccx), |
| _ => bug!("unsupported float: {:?}", self) |
| } |
| } |
| RegKind::Vector => { |
| Type::vector(&Type::i8(ccx), self.size.bytes()) |
| } |
| } |
| } |
| } |
| |
| /// An argument passed entirely registers with the |
| /// same kind (e.g. HFA / HVA on PPC64 and AArch64). |
| #[derive(Copy, Clone)] |
| 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 { |
| fn llvm_type(&self, ccx: &CrateContext) -> Type { |
| let llunit = self.unit.llvm_type(ccx); |
| |
| 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(ccx, rem_bytes * 8))) |
| .collect(); |
| |
| Type::struct_(ccx, &args, false) |
| } |
| } |
| |
| pub trait LayoutExt<'tcx> { |
| fn is_aggregate(&self) -> bool; |
| fn homogeneous_aggregate<'a>(&self, ccx: &CrateContext<'a, 'tcx>) -> Option<Reg>; |
| } |
| |
| impl<'tcx> LayoutExt<'tcx> for TyLayout<'tcx> { |
| fn is_aggregate(&self) -> bool { |
| match *self.layout { |
| Layout::Scalar { .. } | |
| Layout::RawNullablePointer { .. } | |
| Layout::CEnum { .. } | |
| Layout::Vector { .. } => false, |
| |
| Layout::Array { .. } | |
| Layout::FatPointer { .. } | |
| Layout::Univariant { .. } | |
| Layout::UntaggedUnion { .. } | |
| Layout::General { .. } | |
| Layout::StructWrappedNullablePointer { .. } => true |
| } |
| } |
| |
| fn homogeneous_aggregate<'a>(&self, ccx: &CrateContext<'a, 'tcx>) -> Option<Reg> { |
| match *self.layout { |
| // The primitives for this algorithm. |
| Layout::Scalar { value, .. } | |
| Layout::RawNullablePointer { value, .. } => { |
| let kind = match value { |
| layout::Int(_) | |
| layout::Pointer => RegKind::Integer, |
| layout::F32 | |
| layout::F64 => RegKind::Float |
| }; |
| Some(Reg { |
| kind, |
| size: self.size(ccx) |
| }) |
| } |
| |
| Layout::CEnum { .. } => { |
| Some(Reg { |
| kind: RegKind::Integer, |
| size: self.size(ccx) |
| }) |
| } |
| |
| Layout::Vector { .. } => { |
| Some(Reg { |
| kind: RegKind::Vector, |
| size: self.size(ccx) |
| }) |
| } |
| |
| Layout::Array { count, .. } => { |
| if count > 0 { |
| self.field(ccx, 0).homogeneous_aggregate(ccx) |
| } else { |
| None |
| } |
| } |
| |
| Layout::Univariant { ref variant, .. } => { |
| let mut unaligned_offset = Size::from_bytes(0); |
| let mut result = None; |
| |
| for i in 0..self.field_count() { |
| if unaligned_offset != variant.offsets[i] { |
| return None; |
| } |
| |
| let field = self.field(ccx, i); |
| match (result, field.homogeneous_aggregate(ccx)) { |
| // 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(ccx); |
| match unaligned_offset.checked_add(size, ccx) { |
| Some(offset) => unaligned_offset = offset, |
| None => return None |
| } |
| } |
| |
| // There needs to be no padding. |
| if unaligned_offset != self.size(ccx) { |
| None |
| } else { |
| result |
| } |
| } |
| |
| Layout::UntaggedUnion { .. } => { |
| let mut max = Size::from_bytes(0); |
| let mut result = None; |
| |
| for i in 0..self.field_count() { |
| let field = self.field(ccx, i); |
| match (result, field.homogeneous_aggregate(ccx)) { |
| // 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(ccx); |
| if size > max { |
| max = size; |
| } |
| } |
| |
| // There needs to be no padding. |
| if max != self.size(ccx) { |
| None |
| } else { |
| result |
| } |
| } |
| |
| // Rust-specific types, which we can ignore for C ABIs. |
| Layout::FatPointer { .. } | |
| Layout::General { .. } | |
| Layout::StructWrappedNullablePointer { .. } => None |
| } |
| } |
| } |
| |
| 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 { |
| fn llvm_type(&self, ccx: &CrateContext) -> Type { |
| match *self { |
| CastTarget::Uniform(u) => u.llvm_type(ccx), |
| CastTarget::Pair(a, b) => { |
| Type::struct_(ccx, &[ |
| a.llvm_type(ccx), |
| b.llvm_type(ccx) |
| ], false) |
| } |
| } |
| } |
| } |
| |
| /// Information about how a specific C type |
| /// should be passed to or returned from a function |
| /// |
| /// This is borrowed from clang's ABIInfo.h |
| #[derive(Clone, Copy, Debug)] |
| pub struct ArgType<'tcx> { |
| kind: ArgKind, |
| pub layout: TyLayout<'tcx>, |
| /// Coerced LLVM Type |
| pub cast: Option<Type>, |
| /// Dummy argument, which is emitted before the real argument |
| pub pad: Option<Type>, |
| /// LLVM attributes of argument |
| pub attrs: ArgAttributes |
| } |
| |
| impl<'a, 'tcx> ArgType<'tcx> { |
| fn new(layout: TyLayout<'tcx>) -> ArgType<'tcx> { |
| ArgType { |
| kind: ArgKind::Direct, |
| layout, |
| cast: None, |
| pad: None, |
| attrs: ArgAttributes::default() |
| } |
| } |
| |
| pub fn make_indirect(&mut self, ccx: &CrateContext<'a, 'tcx>) { |
| assert_eq!(self.kind, ArgKind::Direct); |
| |
| // Wipe old attributes, likely not valid through indirection. |
| self.attrs = ArgAttributes::default(); |
| |
| let llarg_sz = self.layout.size(ccx).bytes(); |
| |
| // 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 |
| self.attrs.set(ArgAttribute::NoAlias) |
| .set(ArgAttribute::NoCapture) |
| .set_dereferenceable(llarg_sz); |
| |
| self.kind = ArgKind::Indirect; |
| } |
| |
| pub fn ignore(&mut self) { |
| assert_eq!(self.kind, ArgKind::Direct); |
| self.kind = ArgKind::Ignore; |
| } |
| |
| pub fn extend_integer_width_to(&mut self, bits: u64) { |
| // Only integers have signedness |
| let (i, signed) = match *self.layout { |
| Layout::Scalar { value, .. } => { |
| match value { |
| layout::Int(i) => { |
| if self.layout.ty.is_integral() { |
| (i, self.layout.ty.is_signed()) |
| } else { |
| return; |
| } |
| } |
| _ => return |
| } |
| } |
| |
| // Rust enum types that map onto C enums also need to follow |
| // the target ABI zero-/sign-extension rules. |
| Layout::CEnum { discr, signed, .. } => (discr, signed), |
| |
| _ => return |
| }; |
| |
| if i.size().bits() < bits { |
| self.attrs.set(if signed { |
| ArgAttribute::SExt |
| } else { |
| ArgAttribute::ZExt |
| }); |
| } |
| } |
| |
| pub fn cast_to<T: Into<CastTarget>>(&mut self, ccx: &CrateContext, target: T) { |
| self.cast = Some(target.into().llvm_type(ccx)); |
| } |
| |
| pub fn pad_with(&mut self, ccx: &CrateContext, reg: Reg) { |
| self.pad = Some(reg.llvm_type(ccx)); |
| } |
| |
| pub fn is_indirect(&self) -> bool { |
| self.kind == ArgKind::Indirect |
| } |
| |
| pub fn is_ignore(&self) -> bool { |
| self.kind == ArgKind::Ignore |
| } |
| |
| /// Get the LLVM type for an lvalue of the original Rust type of |
| /// this argument/return, i.e. the result of `type_of::type_of`. |
| pub fn memory_ty(&self, ccx: &CrateContext<'a, 'tcx>) -> Type { |
| type_of::type_of(ccx, self.layout.ty) |
| } |
| |
| /// Store a direct/indirect value described by this ArgType into a |
| /// lvalue 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, bcx: &Builder<'a, 'tcx>, mut val: ValueRef, dst: ValueRef) { |
| if self.is_ignore() { |
| return; |
| } |
| let ccx = bcx.ccx; |
| if self.is_indirect() { |
| let llsz = C_usize(ccx, self.layout.size(ccx).bytes()); |
| let llalign = self.layout.align(ccx).abi(); |
| base::call_memcpy(bcx, dst, val, llsz, llalign as u32); |
| } else if let Some(ty) = self.cast { |
| // 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 = bcx.pointercast(dst, ty.ptr_to()); |
| let llalign = self.layout.align(ccx).abi(); |
| bcx.store(val, cast_dst, Some(llalign as u32)); |
| } 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 llscratch = bcx.alloca(ty, "abi_cast", None); |
| base::Lifetime::Start.call(bcx, llscratch); |
| |
| // ...where we first store the value... |
| bcx.store(val, llscratch, None); |
| |
| // ...and then memcpy it to the intended destination. |
| base::call_memcpy(bcx, |
| bcx.pointercast(dst, Type::i8p(ccx)), |
| bcx.pointercast(llscratch, Type::i8p(ccx)), |
| C_usize(ccx, self.layout.size(ccx).bytes()), |
| cmp::min(self.layout.align(ccx).abi() as u32, |
| llalign_of_min(ccx, ty))); |
| |
| base::Lifetime::End.call(bcx, llscratch); |
| } |
| } else { |
| if self.layout.ty == ccx.tcx().types.bool { |
| val = bcx.zext(val, Type::i8(ccx)); |
| } |
| bcx.store(val, dst, None); |
| } |
| } |
| |
| pub fn store_fn_arg(&self, bcx: &Builder<'a, 'tcx>, idx: &mut usize, dst: ValueRef) { |
| if self.pad.is_some() { |
| *idx += 1; |
| } |
| if self.is_ignore() { |
| return; |
| } |
| let val = llvm::get_param(bcx.llfn(), *idx as c_uint); |
| *idx += 1; |
| self.store(bcx, val, 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(Clone, 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(ccx: &CrateContext<'a, 'tcx>, instance: &ty::Instance<'tcx>) |
| -> Self { |
| let fn_ty = instance_ty(ccx.tcx(), &instance); |
| let sig = ty_fn_sig(ccx, fn_ty); |
| let sig = ccx.tcx().erase_late_bound_regions_and_normalize(&sig); |
| Self::new(ccx, sig, &[]) |
| } |
| |
| pub fn new(ccx: &CrateContext<'a, 'tcx>, |
| sig: ty::FnSig<'tcx>, |
| extra_args: &[Ty<'tcx>]) -> FnType<'tcx> { |
| let mut fn_ty = FnType::unadjusted(ccx, sig, extra_args); |
| fn_ty.adjust_for_abi(ccx, sig); |
| fn_ty |
| } |
| |
| pub fn new_vtable(ccx: &CrateContext<'a, 'tcx>, |
| sig: ty::FnSig<'tcx>, |
| extra_args: &[Ty<'tcx>]) -> FnType<'tcx> { |
| let mut fn_ty = FnType::unadjusted(ccx, sig, extra_args); |
| // Don't pass the vtable, it's not an argument of the virtual fn. |
| fn_ty.args[1].ignore(); |
| fn_ty.adjust_for_abi(ccx, sig); |
| fn_ty |
| } |
| |
| pub fn unadjusted(ccx: &CrateContext<'a, 'tcx>, |
| sig: ty::FnSig<'tcx>, |
| extra_args: &[Ty<'tcx>]) -> FnType<'tcx> { |
| debug!("FnType::unadjusted({:?}, {:?})", sig, extra_args); |
| |
| use self::Abi::*; |
| let cconv = match ccx.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 = &ccx.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 |
| }; |
| |
| let arg_of = |ty: Ty<'tcx>, is_return: bool| { |
| let mut arg = ArgType::new(ccx.layout_of(ty)); |
| if ty.is_bool() { |
| arg.attrs.set(ArgAttribute::ZExt); |
| } else { |
| if arg.layout.size(ccx).bytes() == 0 { |
| // 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.ignore(); |
| } |
| } |
| } |
| arg |
| }; |
| |
| let ret_ty = sig.output(); |
| let mut ret = arg_of(ret_ty, true); |
| |
| if !type_is_fat_ptr(ccx, ret_ty) { |
| // The `noalias` attribute on the return value is useful to a |
| // function ptr caller. |
| if ret_ty.is_box() { |
| // `Box` pointer return values never alias because ownership |
| // is transferred |
| ret.attrs.set(ArgAttribute::NoAlias); |
| } |
| |
| // We can also mark the return value as `dereferenceable` in certain cases |
| match ret_ty.sty { |
| // These are not really pointers but pairs, (pointer, len) |
| ty::TyRef(_, ty::TypeAndMut { ty, .. }) => { |
| ret.attrs.set_dereferenceable(ccx.size_of(ty)); |
| } |
| ty::TyAdt(def, _) if def.is_box() => { |
| ret.attrs.set_dereferenceable(ccx.size_of(ret_ty.boxed_ty())); |
| } |
| _ => {} |
| } |
| } |
| |
| let mut args = Vec::with_capacity(inputs.len() + extra_args.len()); |
| |
| // Handle safe Rust thin and fat pointers. |
| let rust_ptr_attrs = |ty: Ty<'tcx>, arg: &mut ArgType| match ty.sty { |
| // `Box` pointer parameters never alias because ownership is transferred |
| ty::TyAdt(def, _) if def.is_box() => { |
| arg.attrs.set(ArgAttribute::NoAlias); |
| Some(ty.boxed_ty()) |
| } |
| |
| ty::TyRef(_, mt) => { |
| // `&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 is_freeze = ccx.shared().type_is_freeze(mt.ty); |
| |
| let no_alias_is_safe = |
| if ccx.shared().tcx().sess.opts.debugging_opts.mutable_noalias || |
| ccx.shared().tcx().sess.panic_strategy() == PanicStrategy::Abort { |
| // Mutable refrences or immutable shared references |
| mt.mutbl == hir::MutMutable || is_freeze |
| } else { |
| // Only immutable shared references |
| mt.mutbl != hir::MutMutable && is_freeze |
| }; |
| |
| if no_alias_is_safe { |
| arg.attrs.set(ArgAttribute::NoAlias); |
| } |
| |
| if mt.mutbl == hir::MutImmutable && is_freeze { |
| arg.attrs.set(ArgAttribute::ReadOnly); |
| } |
| |
| Some(mt.ty) |
| } |
| _ => None |
| }; |
| |
| for ty in inputs.iter().chain(extra_args.iter()) { |
| let mut arg = arg_of(ty, false); |
| |
| if let ty::layout::FatPointer { .. } = *arg.layout { |
| let mut data = ArgType::new(arg.layout.field(ccx, 0)); |
| let mut info = ArgType::new(arg.layout.field(ccx, 1)); |
| |
| if let Some(inner) = rust_ptr_attrs(ty, &mut data) { |
| data.attrs.set(ArgAttribute::NonNull); |
| if ccx.tcx().struct_tail(inner).is_trait() { |
| // vtables can be safely marked non-null, readonly |
| // and noalias. |
| info.attrs.set(ArgAttribute::NonNull); |
| info.attrs.set(ArgAttribute::ReadOnly); |
| info.attrs.set(ArgAttribute::NoAlias); |
| } |
| } |
| args.push(data); |
| args.push(info); |
| } else { |
| if let Some(inner) = rust_ptr_attrs(ty, &mut arg) { |
| arg.attrs.set_dereferenceable(ccx.size_of(inner)); |
| } |
| args.push(arg); |
| } |
| } |
| |
| FnType { |
| args, |
| ret, |
| variadic: sig.variadic, |
| cconv, |
| } |
| } |
| |
| fn adjust_for_abi(&mut self, |
| ccx: &CrateContext<'a, 'tcx>, |
| sig: ty::FnSig<'tcx>) { |
| let abi = sig.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.layout.is_aggregate() { |
| return; |
| } |
| |
| let size = arg.layout.size(ccx); |
| |
| if let Some(unit) = arg.layout.homogeneous_aggregate(ccx) { |
| // Replace newtypes with their inner-most type. |
| if unit.size == size { |
| // Needs a cast as we've unpacked a newtype. |
| arg.cast_to(ccx, unit); |
| return; |
| } |
| |
| // Pairs of floats. |
| if unit.kind == RegKind::Float { |
| if unit.size.checked_mul(2, ccx) == Some(size) { |
| // FIXME(eddyb) This should be using Uniform instead of a pair, |
| // but the resulting [2 x float/double] breaks emscripten. |
| // See https://github.com/kripken/emscripten-fastcomp/issues/178. |
| arg.cast_to(ccx, CastTarget::Pair(unit, unit)); |
| return; |
| } |
| } |
| } |
| |
| if size > layout::Pointer.size(ccx) { |
| arg.make_indirect(ccx); |
| } 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(ccx, Reg { |
| kind: RegKind::Integer, |
| size |
| }); |
| } |
| }; |
| // Fat pointers are returned by-value. |
| if !self.ret.is_ignore() { |
| if !type_is_fat_ptr(ccx, sig.output()) { |
| fixup(&mut self.ret); |
| } |
| } |
| for arg in &mut self.args { |
| if arg.is_ignore() { continue; } |
| fixup(arg); |
| } |
| if self.ret.is_indirect() { |
| self.ret.attrs.set(ArgAttribute::StructRet); |
| } |
| return; |
| } |
| |
| match &ccx.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(ccx, self, flavor); |
| }, |
| "x86_64" => if abi == Abi::SysV64 { |
| cabi_x86_64::compute_abi_info(ccx, self); |
| } else if abi == Abi::Win64 || ccx.sess().target.target.options.is_like_windows { |
| cabi_x86_win64::compute_abi_info(ccx, self); |
| } else { |
| cabi_x86_64::compute_abi_info(ccx, self); |
| }, |
| "aarch64" => cabi_aarch64::compute_abi_info(ccx, self), |
| "arm" => cabi_arm::compute_abi_info(ccx, self), |
| "mips" => cabi_mips::compute_abi_info(ccx, self), |
| "mips64" => cabi_mips64::compute_abi_info(ccx, self), |
| "powerpc" => cabi_powerpc::compute_abi_info(ccx, self), |
| "powerpc64" => cabi_powerpc64::compute_abi_info(ccx, self), |
| "s390x" => cabi_s390x::compute_abi_info(ccx, self), |
| "asmjs" => cabi_asmjs::compute_abi_info(ccx, self), |
| "wasm32" => cabi_asmjs::compute_abi_info(ccx, self), |
| "msp430" => cabi_msp430::compute_abi_info(ccx, self), |
| "sparc" => cabi_sparc::compute_abi_info(ccx, self), |
| "sparc64" => cabi_sparc64::compute_abi_info(ccx, self), |
| "nvptx" => cabi_nvptx::compute_abi_info(ccx, self), |
| "nvptx64" => cabi_nvptx64::compute_abi_info(ccx, self), |
| "hexagon" => cabi_hexagon::compute_abi_info(ccx, self), |
| a => ccx.sess().fatal(&format!("unrecognized arch \"{}\" in target specification", a)) |
| } |
| |
| if self.ret.is_indirect() { |
| self.ret.attrs.set(ArgAttribute::StructRet); |
| } |
| } |
| |
| pub fn llvm_type(&self, ccx: &CrateContext<'a, 'tcx>) -> Type { |
| let mut llargument_tys = Vec::new(); |
| |
| let llreturn_ty = if self.ret.is_ignore() { |
| Type::void(ccx) |
| } else if self.ret.is_indirect() { |
| llargument_tys.push(self.ret.memory_ty(ccx).ptr_to()); |
| Type::void(ccx) |
| } else { |
| self.ret.cast.unwrap_or_else(|| { |
| type_of::immediate_type_of(ccx, self.ret.layout.ty) |
| }) |
| }; |
| |
| for arg in &self.args { |
| if arg.is_ignore() { |
| continue; |
| } |
| // add padding |
| if let Some(ty) = arg.pad { |
| llargument_tys.push(ty); |
| } |
| |
| let llarg_ty = if arg.is_indirect() { |
| arg.memory_ty(ccx).ptr_to() |
| } else { |
| arg.cast.unwrap_or_else(|| { |
| type_of::immediate_type_of(ccx, arg.layout.ty) |
| }) |
| }; |
| |
| 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 = if self.ret.is_indirect() { 1 } else { 0 }; |
| if !self.ret.is_ignore() { |
| self.ret.attrs.apply_llfn(llvm::AttributePlace::Argument(i), llfn); |
| } |
| i += 1; |
| for arg in &self.args { |
| if !arg.is_ignore() { |
| if arg.pad.is_some() { i += 1; } |
| arg.attrs.apply_llfn(llvm::AttributePlace::Argument(i), llfn); |
| i += 1; |
| } |
| } |
| } |
| |
| pub fn apply_attrs_callsite(&self, callsite: ValueRef) { |
| let mut i = if self.ret.is_indirect() { 1 } else { 0 }; |
| if !self.ret.is_ignore() { |
| self.ret.attrs.apply_callsite(llvm::AttributePlace::Argument(i), callsite); |
| } |
| i += 1; |
| for arg in &self.args { |
| if !arg.is_ignore() { |
| if arg.pad.is_some() { i += 1; } |
| arg.attrs.apply_callsite(llvm::AttributePlace::Argument(i), callsite); |
| i += 1; |
| } |
| } |
| |
| if self.cconv != llvm::CCallConv { |
| llvm::SetInstructionCallConv(callsite, self.cconv); |
| } |
| } |
| } |
| |
| pub fn align_up_to(off: u64, a: u64) -> u64 { |
| (off + a - 1) / a * a |
| } |