rust/src/abi.rs

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Rust
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2020-05-10 10:54:30 -04:00
use gccjit::{ToRValue, Type};
use rustc_codegen_ssa::traits::{AbiBuilderMethods, BaseTypeMethods};
use rustc_middle::bug;
use rustc_middle::ty::Ty;
use rustc_target::abi::call::{CastTarget, FnAbi, PassMode, Reg, RegKind};
use crate::builder::Builder;
use crate::context::CodegenCx;
use crate::intrinsic::ArgAbiExt;
use crate::type_of::LayoutGccExt;
impl<'a, 'gcc, 'tcx> AbiBuilderMethods<'tcx> for Builder<'a, 'gcc, 'tcx> {
fn apply_attrs_callsite(&mut self, _fn_abi: &FnAbi<'tcx, Ty<'tcx>>, _callsite: Self::Value) {
// TODO
//fn_abi.apply_attrs_callsite(self, callsite)
}
fn get_param(&self, index: usize) -> Self::Value {
self.cx.current_func.borrow().expect("current func")
.get_param(index as i32)
.to_rvalue()
}
}
impl GccType for CastTarget {
fn gcc_type<'gcc>(&self, cx: &CodegenCx<'gcc, '_>) -> Type<'gcc> {
let rest_gcc_unit = self.rest.unit.gcc_type(cx);
let (rest_count, rem_bytes) =
if self.rest.unit.size.bytes() == 0 {
(0, 0)
}
else {
(self.rest.total.bytes() / self.rest.unit.size.bytes(), self.rest.total.bytes() % self.rest.unit.size.bytes())
};
if self.prefix.iter().all(|x| x.is_none()) {
// Simplify to a single unit when there is no prefix and size <= unit size
if self.rest.total <= self.rest.unit.size {
return rest_gcc_unit;
}
// Simplify to array when all chunks are the same size and type
if rem_bytes == 0 {
return cx.type_array(rest_gcc_unit, rest_count);
}
}
// Create list of fields in the main structure
let mut args: Vec<_> = self
.prefix
.iter()
.flat_map(|option_kind| {
option_kind.map(|kind| Reg { kind, size: self.prefix_chunk_size }.gcc_type(cx))
})
.chain((0..rest_count).map(|_| rest_gcc_unit))
.collect();
// Append final integer
if rem_bytes != 0 {
// Only integers can be really split further.
assert_eq!(self.rest.unit.kind, RegKind::Integer);
args.push(cx.type_ix(rem_bytes * 8));
}
cx.type_struct(&args, false)
}
}
pub trait GccType {
fn gcc_type<'gcc>(&self, cx: &CodegenCx<'gcc, '_>) -> Type<'gcc>;
}
impl GccType for Reg {
fn gcc_type<'gcc>(&self, cx: &CodegenCx<'gcc, '_>) -> Type<'gcc> {
match self.kind {
RegKind::Integer => cx.type_ix(self.size.bits()),
RegKind::Float => {
match self.size.bits() {
32 => cx.type_f32(),
64 => cx.type_f64(),
_ => bug!("unsupported float: {:?}", self),
}
},
RegKind::Vector => unimplemented!(), //cx.type_vector(cx.type_i8(), self.size.bytes()),
}
}
}
pub trait FnAbiGccExt<'gcc, 'tcx> {
// TODO: return a function pointer type instead?
fn gcc_type(&self, cx: &CodegenCx<'gcc, 'tcx>) -> (Type<'gcc>, Vec<Type<'gcc>>, bool);
fn ptr_to_gcc_type(&self, cx: &CodegenCx<'gcc, 'tcx>) -> Type<'gcc>;
/*fn llvm_cconv(&self) -> llvm::CallConv;
fn apply_attrs_llfn(&self, cx: &CodegenCx<'ll, 'tcx>, llfn: &'ll Value);
fn apply_attrs_callsite(&self, bx: &mut Builder<'a, 'll, 'tcx>, callsite: &'ll Value);*/
}
impl<'gcc, 'tcx> FnAbiGccExt<'gcc, 'tcx> for FnAbi<'tcx, Ty<'tcx>> {
fn gcc_type(&self, cx: &CodegenCx<'gcc, 'tcx>) -> (Type<'gcc>, Vec<Type<'gcc>>, bool) {
let args_capacity: usize = self.args.iter().map(|arg|
if arg.pad.is_some() {
1
}
else {
0
} +
if let PassMode::Pair(_, _) = arg.mode {
2
} else {
1
}
).sum();
let mut argument_tys = Vec::with_capacity(
if let PassMode::Indirect { .. } = self.ret.mode {
1
}
else {
0
} + args_capacity,
);
let return_ty =
match self.ret.mode {
PassMode::Ignore => cx.type_void(),
PassMode::Direct(_) | PassMode::Pair(..) => self.ret.layout.immediate_gcc_type(cx),
PassMode::Cast(cast) => cast.gcc_type(cx),
PassMode::Indirect { .. } => {
argument_tys.push(cx.type_ptr_to(self.ret.memory_ty(cx)));
cx.type_void()
}
};
for arg in &self.args {
// add padding
if let Some(ty) = arg.pad {
argument_tys.push(ty.gcc_type(cx));
}
let arg_ty = match arg.mode {
PassMode::Ignore => continue,
PassMode::Direct(_) => arg.layout.immediate_gcc_type(cx),
PassMode::Pair(..) => {
argument_tys.push(arg.layout.scalar_pair_element_gcc_type(cx, 0, true));
argument_tys.push(arg.layout.scalar_pair_element_gcc_type(cx, 1, true));
continue;
}
PassMode::Indirect { extra_attrs: Some(_), .. } => {
/*let ptr_ty = cx.tcx.mk_mut_ptr(arg.layout.ty);
let ptr_layout = cx.layout_of(ptr_ty);
argument_tys.push(ptr_layout.scalar_pair_element_gcc_type(cx, 0, true));
argument_tys.push(ptr_layout.scalar_pair_element_gcc_type(cx, 1, true));*/
unimplemented!();
//continue;
}
PassMode::Cast(cast) => cast.gcc_type(cx),
PassMode::Indirect { extra_attrs: None, .. } => cx.type_ptr_to(arg.memory_ty(cx)),
};
argument_tys.push(arg_ty);
}
(return_ty, argument_tys, self.c_variadic)
}
fn ptr_to_gcc_type(&self, cx: &CodegenCx<'gcc, 'tcx>) -> Type<'gcc> {
let (return_type, params, variadic) = self.gcc_type(cx);
let pointer_type = cx.context.new_function_pointer_type(None, return_type, &params, variadic);
pointer_type
}
/*fn llvm_cconv(&self) -> llvm::CallConv {
match self.conv {
Conv::C | Conv::Rust => llvm::CCallConv,
Conv::AmdGpuKernel => llvm::AmdGpuKernel,
Conv::ArmAapcs => llvm::ArmAapcsCallConv,
Conv::Msp430Intr => llvm::Msp430Intr,
Conv::PtxKernel => llvm::PtxKernel,
Conv::X86Fastcall => llvm::X86FastcallCallConv,
Conv::X86Intr => llvm::X86_Intr,
Conv::X86Stdcall => llvm::X86StdcallCallConv,
Conv::X86ThisCall => llvm::X86_ThisCall,
Conv::X86VectorCall => llvm::X86_VectorCall,
Conv::X86_64SysV => llvm::X86_64_SysV,
Conv::X86_64Win64 => llvm::X86_64_Win64,
}
}
fn apply_attrs_llfn(&self, cx: &CodegenCx<'ll, 'tcx>, llfn: &'ll Value) {
// FIXME(eddyb) can this also be applied to callsites?
if self.ret.layout.abi.is_uninhabited() {
llvm::Attribute::NoReturn.apply_llfn(llvm::AttributePlace::Function, llfn);
}
// FIXME(eddyb, wesleywiser): apply this to callsites as well?
if !self.can_unwind {
llvm::Attribute::NoUnwind.apply_llfn(llvm::AttributePlace::Function, llfn);
}
let mut i = 0;
let mut apply = |attrs: &ArgAttributes, ty: Option<&Type>| {
attrs.apply_llfn(llvm::AttributePlace::Argument(i), llfn, ty);
i += 1;
};
match self.ret.mode {
PassMode::Direct(ref attrs) => {
attrs.apply_llfn(llvm::AttributePlace::ReturnValue, llfn, None);
}
PassMode::Indirect(ref attrs, _) => apply(attrs, Some(self.ret.layout.gcc_type(cx))),
_ => {}
}
for arg in &self.args {
if arg.pad.is_some() {
apply(&ArgAttributes::new(), None);
}
match arg.mode {
PassMode::Ignore => {}
PassMode::Direct(ref attrs) | PassMode::Indirect(ref attrs, None) => {
apply(attrs, Some(arg.layout.gcc_type(cx)))
}
PassMode::Indirect(ref attrs, Some(ref extra_attrs)) => {
apply(attrs, None);
apply(extra_attrs, None);
}
PassMode::Pair(ref a, ref b) => {
apply(a, None);
apply(b, None);
}
PassMode::Cast(_) => apply(&ArgAttributes::new(), None),
}
}
}
fn apply_attrs_callsite(&self, bx: &mut Builder<'a, 'll, 'tcx>, callsite: &'ll Value) {
// FIXME(wesleywiser, eddyb): We should apply `nounwind` and `noreturn` as appropriate to this callsite.
let mut i = 0;
let mut apply = |attrs: &ArgAttributes, ty: Option<&Type>| {
attrs.apply_callsite(llvm::AttributePlace::Argument(i), callsite, ty);
i += 1;
};
match self.ret.mode {
PassMode::Direct(ref attrs) => {
attrs.apply_callsite(llvm::AttributePlace::ReturnValue, callsite, None);
}
PassMode::Indirect(ref attrs, _) => apply(attrs, Some(self.ret.layout.gcc_type(bx))),
_ => {}
}
if let abi::Abi::Scalar(ref scalar) = self.ret.layout.abi {
// If the value is a boolean, the range is 0..2 and that ultimately
// become 0..0 when the type becomes i1, which would be rejected
// by the LLVM verifier.
if let Int(..) = scalar.value {
if !scalar.is_bool() {
let range = scalar.valid_range_exclusive(bx);
if range.start != range.end {
bx.range_metadata(callsite, range);
}
}
}
}
for arg in &self.args {
if arg.pad.is_some() {
apply(&ArgAttributes::new(), None);
}
match arg.mode {
PassMode::Ignore => {}
PassMode::Direct(ref attrs) | PassMode::Indirect(ref attrs, None) => {
apply(attrs, Some(arg.layout.gcc_type(bx)))
}
PassMode::Indirect(ref attrs, Some(ref extra_attrs)) => {
apply(attrs, None);
apply(extra_attrs, None);
}
PassMode::Pair(ref a, ref b) => {
apply(a, None);
apply(b, None);
}
PassMode::Cast(_) => apply(&ArgAttributes::new(), None),
}
}
let cconv = self.llvm_cconv();
if cconv != llvm::CCallConv {
llvm::SetInstructionCallConv(callsite, cconv);
}
}*/
}