bjoernager/rust
bjoernager/rust
1
Fork 0
Code Activity

refactor complete

Browse source
This commit is contained in:
Saleem Jaffer 2019-05-14 15:20:29 +05:30
parent 3031705009
commit e1b3c79d5c
3 changed files with 12 additions and 377 deletions
Download patch file Download diff file Expand all files Collapse all files

379
src/librustc_codegen_llvm/abi.rs
View file

@ -11,9 +11,9 @@ use rustc_target::abi::call::ArgType;
use rustc_codegen_ssa::traits::*;
use rustc_target::abi::{HasDataLayout, LayoutOf, Size, TyLayout, Abi as LayoutAbi};
use rustc_target::abi::{HasDataLayout, LayoutOf};
use rustc::ty::{self, Ty, Instance};
use rustc::ty::layout::{self, PointerKind};
use rustc::ty::layout::{self, FnTypeExt};
use libc::c_uint;
@ -294,23 +294,7 @@ impl ArgTypeMethods<'tcx> for Builder<'a, 'll, 'tcx> {
}
}
pub trait FnTypeExt<'tcx> {
fn of_instance(cx: &CodegenCx<'ll, 'tcx>, instance: &ty::Instance<'tcx>) -> Self;
fn new(cx: &CodegenCx<'ll, 'tcx>,
sig: ty::FnSig<'tcx>,
extra_args: &[Ty<'tcx>]) -> Self;
fn new_vtable(cx: &CodegenCx<'ll, 'tcx>,
sig: ty::FnSig<'tcx>,
extra_args: &[Ty<'tcx>]) -> Self;
fn new_internal(
cx: &CodegenCx<'ll, 'tcx>,
sig: ty::FnSig<'tcx>,
extra_args: &[Ty<'tcx>],
mk_arg_type: impl Fn(Ty<'tcx>, Option<usize>) -> ArgType<'tcx, Ty<'tcx>>,
) -> Self;
fn adjust_for_abi(&mut self,
cx: &CodegenCx<'ll, 'tcx>,
abi: Abi);
pub trait FnTypeLlvmExt<'tcx> {
fn llvm_type(&self, cx: &CodegenCx<'ll, 'tcx>) -> &'ll Type;
fn ptr_to_llvm_type(&self, cx: &CodegenCx<'ll, 'tcx>) -> &'ll Type;
fn llvm_cconv(&self) -> llvm::CallConv;
@ -318,356 +302,7 @@ pub trait FnTypeExt<'tcx> {
fn apply_attrs_callsite(&self, bx: &mut Builder<'a, 'll, 'tcx>, callsite: &'ll Value);
}
impl<'tcx> FnTypeExt<'tcx> for FnType<'tcx, Ty<'tcx>> {
fn of_instance(cx: &CodegenCx<'ll, 'tcx>, instance: &ty::Instance<'tcx>) -> Self {
let sig = instance.fn_sig(cx.tcx);
let sig = cx.tcx.normalize_erasing_late_bound_regions(ty::ParamEnv::reveal_all(), &sig);
FnTypeExt::new(cx, sig, &[])
}
fn new(cx: &CodegenCx<'ll, 'tcx>,
sig: ty::FnSig<'tcx>,
extra_args: &[Ty<'tcx>]) -> Self {
FnTypeExt::new_internal(cx, sig, extra_args, |ty, _| {
ArgType::new(cx.layout_of(ty))
})
}
fn new_vtable(cx: &CodegenCx<'ll, 'tcx>,
sig: ty::FnSig<'tcx>,
extra_args: &[Ty<'tcx>]) -> Self {
FnTypeExt::new_internal(cx, sig, extra_args, |ty, arg_idx| {
let mut layout = cx.layout_of(ty);
// Don't pass the vtable, it's not an argument of the virtual fn.
// Instead, pass just the data pointer, but give it the type `*const/mut dyn Trait`
// or `&/&mut dyn Trait` because this is special-cased elsewhere in codegen
if arg_idx == Some(0) {
let fat_pointer_ty = if layout.is_unsized() {
// unsized `self` is passed as a pointer to `self`
// FIXME (mikeyhew) change this to use &own if it is ever added to the language
cx.tcx.mk_mut_ptr(layout.ty)
} else {
match layout.abi {
LayoutAbi::ScalarPair(..) => (),
_ => bug!("receiver type has unsupported layout: {:?}", layout)
}
// 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 a `dyn Trait`.
// To get the type `*mut RcBox<Self>`, we just keep unwrapping newtypes until we
// get a built-in pointer type
let mut fat_pointer_layout = layout;
'descend_newtypes: while !fat_pointer_layout.ty.is_unsafe_ptr()
&& !fat_pointer_layout.ty.is_region_ptr()
{
'iter_fields: for i in 0..fat_pointer_layout.fields.count() {
let field_layout = fat_pointer_layout.field(cx, i);
if !field_layout.is_zst() {
fat_pointer_layout = field_layout;
continue 'descend_newtypes
}
}
bug!("receiver has no non-zero-sized fields {:?}", fat_pointer_layout);
}
fat_pointer_layout.ty
};
// we now have a type like `*mut RcBox<dyn Trait>`
// change its layout to that of `*mut ()`, a thin pointer, but keep the same type
// this is understood as a special case elsewhere in the compiler
let unit_pointer_ty = cx.tcx.mk_mut_ptr(cx.tcx.mk_unit());
layout = cx.layout_of(unit_pointer_ty);
layout.ty = fat_pointer_ty;
}
ArgType::new(layout)
})
}
fn new_internal(
cx: &CodegenCx<'ll, 'tcx>,
sig: ty::FnSig<'tcx>,
extra_args: &[Ty<'tcx>],
mk_arg_type: impl Fn(Ty<'tcx>, Option<usize>) -> ArgType<'tcx, Ty<'tcx>>,
) -> Self {
debug!("FnType::new_internal({:?}, {:?})", sig, extra_args);
use self::Abi::*;
let conv = match cx.sess().target.target.adjust_abi(sig.abi) {
RustIntrinsic | PlatformIntrinsic |
Rust | RustCall => Conv::C,
// It's the ABI's job to select this, not ours.
System => bug!("system abi should be selected elsewhere"),
Stdcall => Conv::X86Stdcall,
Fastcall => Conv::X86Fastcall,
Vectorcall => Conv::X86VectorCall,
Thiscall => Conv::X86ThisCall,
C => Conv::C,
Unadjusted => Conv::C,
Win64 => Conv::X86_64Win64,
SysV64 => Conv::X86_64SysV,
Aapcs => Conv::ArmAapcs,
PtxKernel => Conv::PtxKernel,
Msp430Interrupt => Conv::Msp430Intr,
X86Interrupt => Conv::X86Intr,
AmdGpuKernel => Conv::AmdGpuKernel,
// These API constants ought to be more specific...
Cdecl => Conv::C,
};
let mut inputs = sig.inputs();
let extra_args = if sig.abi == RustCall {
assert!(!sig.c_variadic && extra_args.is_empty());
match sig.inputs().last().unwrap().sty {
ty::Tuple(tupled_arguments) => {
inputs = &sig.inputs()[0..sig.inputs().len() - 1];
tupled_arguments.iter().map(|k| k.expect_ty()).collect()
}
_ => {
bug!("argument to function with \"rust-call\" ABI \
is not a tuple");
}
}
} else {
assert!(sig.c_variadic || extra_args.is_empty());
extra_args.to_vec()
};
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 linux_sparc64 = target.target_os == "linux"
&& target.arch == "sparc64"
&& 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, Ty<'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);
// `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);
}
}
}
};
// Store the index of the last argument. This is useful for working with
// C-compatible variadic arguments.
let last_arg_idx = if sig.inputs().is_empty() {
None
} else {
Some(sig.inputs().len() - 1)
};
let arg_of = |ty: Ty<'tcx>, arg_idx: Option<usize>| {
let is_return = arg_idx.is_none();
let mut arg = mk_arg_type(ty, arg_idx);
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
// and sparc64-unknown-linux-gnu.
if is_return || rust_abi || (!win_x64_gnu && !linux_s390x && !linux_sparc64) {
arg.mode = PassMode::Ignore(IgnoreMode::Zst);
}
}
// If this is a C-variadic function, this is not the return value,
// and there is one or more fixed arguments; ensure that the `VaList`
// is ignored as an argument.
if sig.c_variadic {
match (last_arg_idx, arg_idx) {
(Some(last_idx), Some(cur_idx)) if last_idx == cur_idx => {
let va_list_did = match cx.tcx.lang_items().va_list() {
Some(did) => did,
None => bug!("`va_list` lang item required for C-variadic functions"),
};
match ty.sty {
ty::Adt(def, _) if def.did == va_list_did => {
// This is the "spoofed" `VaList`. Set the arguments mode
// so that it will be ignored.
arg.mode = PassMode::Ignore(IgnoreMode::CVarArgs);
},
_ => (),
}
}
_ => {}
}
}
// 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::ZERO,
false);
adjust_for_rust_scalar(&mut b_attrs,
b,
arg.layout,
a.value.size(cx).align_to(b.value.align(cx).abi),
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::ZERO,
is_return);
}
}
arg
};
let mut fn_ty = FnType {
ret: arg_of(sig.output(), None),
args: inputs.iter().cloned().chain(extra_args).enumerate().map(|(i, ty)| {
arg_of(ty, Some(i))
}).collect(),
c_variadic: sig.c_variadic,
conv,
};
FnTypeExt::adjust_for_abi(&mut fn_ty, cx, sig.abi);
fn_ty
}
fn adjust_for_abi(&mut self,
cx: &CodegenCx<'ll, '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, Ty<'tcx>>| {
if arg.is_ignore() { return; }
match arg.layout.abi {
layout::Abi::Aggregate { .. } => {}
// This is a fun case! The gist of what this is doing is
// that we want callers and callees to always agree on the
// ABI of how they pass SIMD arguments. If we were to *not*
// make these arguments indirect then they'd be immediates
// in LLVM, which means that they'd used whatever the
// appropriate ABI is for the callee and the caller. That
// means, for example, if the caller doesn't have AVX
// enabled but the callee does, then passing an AVX argument
// across this boundary would cause corrupt data to show up.
//
// This problem is fixed by unconditionally passing SIMD
// arguments through memory between callers and callees
// which should get them all to agree on ABI regardless of
// target feature sets. Some more information about this
// issue can be found in #44367.
//
// Note that the platform intrinsic ABI is exempt here as
// that's how we connect up to LLVM and it's unstable
// anyway, we control all calls to it in libstd.
layout::Abi::Vector { .. }
if abi != Abi::PlatformIntrinsic &&
cx.sess().target.target.options.simd_types_indirect =>
{
arg.make_indirect();
return
}
_ => return
}
let size = arg.layout.size;
if arg.layout.is_unsized() || 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;
}
if let Err(msg) = self.adjust_for_cabi(cx, abi) {
cx.sess().fatal(&msg);
}
}
impl<'tcx> FnTypeLlvmExt<'tcx> for FnType<'tcx, Ty<'tcx>> {
fn llvm_type(&self, cx: &CodegenCx<'ll, 'tcx>) -> &'ll Type {
let args_capacity: usize = self.args.iter().map(|arg|
if arg.pad.is_some() { 1 } else { 0 } +
@ -838,17 +473,17 @@ impl<'tcx> FnTypeExt<'tcx> for FnType<'tcx, Ty<'tcx>> {
impl AbiMethods<'tcx> for CodegenCx<'ll, 'tcx> {
fn new_fn_type(&self, sig: ty::FnSig<'tcx>, extra_args: &[Ty<'tcx>]) -> FnType<'tcx, Ty<'tcx>> {
FnTypeExt::new(&self, sig, extra_args)
FnType::new(self, sig, extra_args)
}
fn new_vtable(
&self,
sig: ty::FnSig<'tcx>,
extra_args: &[Ty<'tcx>]
) -> FnType<'tcx, Ty<'tcx>> {
FnTypeExt::new_vtable(&self, sig, extra_args)
FnType::new_vtable(self, sig, extra_args)
}
fn fn_type_of_instance(&self, instance: &Instance<'tcx>) -> FnType<'tcx, Ty<'tcx>> {
FnTypeExt::of_instance(&self, instance)
FnType::of_instance(self, instance)
}
}

8
src/librustc_codegen_llvm/declare.rs
View file

@ -13,13 +13,13 @@
use crate::llvm;
use crate::llvm::AttributePlace::Function;
use crate::abi::{FnType, FnTypeExt};
use crate::abi::{FnType, FnTypeLlvmExt};
use crate::attributes;
use crate::context::CodegenCx;
use crate::type_::Type;
use crate::value::Value;
use rustc::ty::{self, PolyFnSig, Ty};
use rustc::ty::layout::{FnTypeExt as FnTypeExt1, LayoutOf};
use rustc::ty::{self, PolyFnSig};
use rustc::ty::layout::{FnTypeExt, LayoutOf};
use rustc::session::config::Sanitizer;
use rustc_data_structures::small_c_str::SmallCStr;
use rustc_codegen_ssa::traits::*;
@ -100,7 +100,7 @@ impl DeclareMethods<'tcx> for CodegenCx<'ll, 'tcx> {
let sig = self.tcx.normalize_erasing_late_bound_regions(ty::ParamEnv::reveal_all(), &sig);
debug!("declare_rust_fn (after region erasure) sig={:?}", sig);
let fty: FnType<'tcx, Ty<'tcx>> = FnTypeExt1::new(self, sig, &[]);
let fty= FnType::new(self, sig, &[]);
let llfn = declare_raw_fn(self, name, fty.llvm_cconv(), fty.llvm_type(self));
if self.layout_of(sig.output()).abi.is_uninhabited() {

2
src/librustc_codegen_llvm/type_.rs
View file

@ -10,7 +10,7 @@ use rustc_codegen_ssa::traits::*;
use crate::common;
use crate::type_of::LayoutLlvmExt;
use crate::abi::{LlvmType, FnTypeExt};
use crate::abi::{LlvmType, FnTypeLlvmExt};
use syntax::ast;
use rustc::ty::Ty;
use rustc::ty::layout::{self, Align, Size, TyLayout};