1 use crate::builder::Builder;
2 use crate::context::CodegenCx;
3 use crate::llvm::{self, AttributePlace};
4 use crate::type_::Type;
5 use crate::type_of::LayoutLlvmExt;
6 use crate::value::Value;
8 use rustc_codegen_ssa::mir::operand::OperandValue;
9 use rustc_codegen_ssa::mir::place::PlaceRef;
10 use rustc_codegen_ssa::traits::*;
11 use rustc_codegen_ssa::MemFlags;
12 use rustc_middle::bug;
13 pub use rustc_middle::ty::layout::{FAT_PTR_ADDR, FAT_PTR_EXTRA};
14 use rustc_middle::ty::Ty;
15 use rustc_target::abi::call::ArgAbi;
16 pub use rustc_target::abi::call::*;
17 use rustc_target::abi::{self, HasDataLayout, Int, LayoutOf};
18 pub use rustc_target::spec::abi::Abi;
22 macro_rules! for_each_kind {
23 ($flags: ident, $f: ident, $($kind: ident),+) => ({
24 $(if $flags.contains(ArgAttribute::$kind) { $f(llvm::Attribute::$kind) })+
28 trait ArgAttributeExt {
29 fn for_each_kind<F>(&self, f: F)
31 F: FnMut(llvm::Attribute);
34 impl ArgAttributeExt for ArgAttribute {
35 fn for_each_kind<F>(&self, mut f: F)
37 F: FnMut(llvm::Attribute),
39 for_each_kind!(self, f, NoAlias, NoCapture, NonNull, ReadOnly, InReg)
43 pub trait ArgAttributesExt {
44 fn apply_attrs_to_llfn(&self, idx: AttributePlace, llfn: &Value);
45 fn apply_attrs_to_callsite(&self, idx: AttributePlace, callsite: &Value);
48 impl ArgAttributesExt for ArgAttributes {
49 fn apply_attrs_to_llfn(&self, idx: AttributePlace, llfn: &Value) {
50 let mut regular = self.regular;
52 let deref = self.pointee_size.bytes();
54 if regular.contains(ArgAttribute::NonNull) {
55 llvm::LLVMRustAddDereferenceableAttr(llfn, idx.as_uint(), deref);
57 llvm::LLVMRustAddDereferenceableOrNullAttr(llfn, idx.as_uint(), deref);
59 regular -= ArgAttribute::NonNull;
61 if let Some(align) = self.pointee_align {
62 llvm::LLVMRustAddAlignmentAttr(llfn, idx.as_uint(), align.bytes() as u32);
64 regular.for_each_kind(|attr| attr.apply_llfn(idx, llfn));
66 ArgExtension::None => {}
67 ArgExtension::Zext => {
68 llvm::Attribute::ZExt.apply_llfn(idx, llfn);
70 ArgExtension::Sext => {
71 llvm::Attribute::SExt.apply_llfn(idx, llfn);
77 fn apply_attrs_to_callsite(&self, idx: AttributePlace, callsite: &Value) {
78 let mut regular = self.regular;
80 let deref = self.pointee_size.bytes();
82 if regular.contains(ArgAttribute::NonNull) {
83 llvm::LLVMRustAddDereferenceableCallSiteAttr(callsite, idx.as_uint(), deref);
85 llvm::LLVMRustAddDereferenceableOrNullCallSiteAttr(
91 regular -= ArgAttribute::NonNull;
93 if let Some(align) = self.pointee_align {
94 llvm::LLVMRustAddAlignmentCallSiteAttr(
100 regular.for_each_kind(|attr| attr.apply_callsite(idx, callsite));
102 ArgExtension::None => {}
103 ArgExtension::Zext => {
104 llvm::Attribute::ZExt.apply_callsite(idx, callsite);
106 ArgExtension::Sext => {
107 llvm::Attribute::SExt.apply_callsite(idx, callsite);
115 fn llvm_type(&self, cx: &CodegenCx<'ll, '_>) -> &'ll Type;
118 impl LlvmType for Reg {
119 fn llvm_type(&self, cx: &CodegenCx<'ll, '_>) -> &'ll Type {
121 RegKind::Integer => cx.type_ix(self.size.bits()),
122 RegKind::Float => match self.size.bits() {
125 _ => bug!("unsupported float: {:?}", self),
127 RegKind::Vector => cx.type_vector(cx.type_i8(), self.size.bytes()),
132 impl LlvmType for CastTarget {
133 fn llvm_type(&self, cx: &CodegenCx<'ll, '_>) -> &'ll Type {
134 let rest_ll_unit = self.rest.unit.llvm_type(cx);
135 let (rest_count, rem_bytes) = if self.rest.unit.size.bytes() == 0 {
139 self.rest.total.bytes() / self.rest.unit.size.bytes(),
140 self.rest.total.bytes() % self.rest.unit.size.bytes(),
144 if self.prefix.iter().all(|x| x.is_none()) {
145 // Simplify to a single unit when there is no prefix and size <= unit size
146 if self.rest.total <= self.rest.unit.size {
150 // Simplify to array when all chunks are the same size and type
152 return cx.type_array(rest_ll_unit, rest_count);
156 // Create list of fields in the main structure
157 let mut args: Vec<_> = self
160 .flat_map(|option_kind| {
161 option_kind.map(|kind| Reg { kind, size: self.prefix_chunk_size }.llvm_type(cx))
163 .chain((0..rest_count).map(|_| rest_ll_unit))
166 // Append final integer
168 // Only integers can be really split further.
169 assert_eq!(self.rest.unit.kind, RegKind::Integer);
170 args.push(cx.type_ix(rem_bytes * 8));
173 cx.type_struct(&args, false)
177 pub trait ArgAbiExt<'ll, 'tcx> {
178 fn memory_ty(&self, cx: &CodegenCx<'ll, 'tcx>) -> &'ll Type;
181 bx: &mut Builder<'_, 'll, 'tcx>,
183 dst: PlaceRef<'tcx, &'ll Value>,
187 bx: &mut Builder<'_, 'll, 'tcx>,
189 dst: PlaceRef<'tcx, &'ll Value>,
193 impl ArgAbiExt<'ll, 'tcx> for ArgAbi<'tcx, Ty<'tcx>> {
194 /// Gets the LLVM type for a place of the original Rust type of
195 /// this argument/return, i.e., the result of `type_of::type_of`.
196 fn memory_ty(&self, cx: &CodegenCx<'ll, 'tcx>) -> &'ll Type {
197 self.layout.llvm_type(cx)
200 /// Stores a direct/indirect value described by this ArgAbi into a
201 /// place for the original Rust type of this argument/return.
202 /// Can be used for both storing formal arguments into Rust variables
203 /// or results of call/invoke instructions into their destinations.
206 bx: &mut Builder<'_, 'll, 'tcx>,
208 dst: PlaceRef<'tcx, &'ll Value>,
210 if self.is_ignore() {
213 if self.is_sized_indirect() {
214 OperandValue::Ref(val, None, self.layout.align.abi).store(bx, dst)
215 } else if self.is_unsized_indirect() {
216 bug!("unsized `ArgAbi` must be handled through `store_fn_arg`");
217 } else if let PassMode::Cast(cast) = self.mode {
218 // FIXME(eddyb): Figure out when the simpler Store is safe, clang
219 // uses it for i16 -> {i8, i8}, but not for i24 -> {i8, i8, i8}.
220 let can_store_through_cast_ptr = false;
221 if can_store_through_cast_ptr {
222 let cast_ptr_llty = bx.type_ptr_to(cast.llvm_type(bx));
223 let cast_dst = bx.pointercast(dst.llval, cast_ptr_llty);
224 bx.store(val, cast_dst, self.layout.align.abi);
226 // The actual return type is a struct, but the ABI
227 // adaptation code has cast it into some scalar type. The
228 // code that follows is the only reliable way I have
229 // found to do a transform like i64 -> {i32,i32}.
230 // Basically we dump the data onto the stack then memcpy it.
232 // Other approaches I tried:
233 // - Casting rust ret pointer to the foreign type and using Store
234 // is (a) unsafe if size of foreign type > size of rust type and
235 // (b) runs afoul of strict aliasing rules, yielding invalid
236 // assembly under -O (specifically, the store gets removed).
237 // - Truncating foreign type to correct integral type and then
238 // bitcasting to the struct type yields invalid cast errors.
240 // We instead thus allocate some scratch space...
241 let scratch_size = cast.size(bx);
242 let scratch_align = cast.align(bx);
243 let llscratch = bx.alloca(cast.llvm_type(bx), scratch_align);
244 bx.lifetime_start(llscratch, scratch_size);
246 // ... where we first store the value...
247 bx.store(val, llscratch, scratch_align);
249 // ... and then memcpy it to the intended destination.
252 self.layout.align.abi,
255 bx.const_usize(self.layout.size.bytes()),
259 bx.lifetime_end(llscratch, scratch_size);
262 OperandValue::Immediate(val).store(bx, dst);
268 bx: &mut Builder<'a, 'll, 'tcx>,
270 dst: PlaceRef<'tcx, &'ll Value>,
273 let val = llvm::get_param(bx.llfn(), *idx as c_uint);
278 PassMode::Ignore => {}
279 PassMode::Pair(..) => {
280 OperandValue::Pair(next(), next()).store(bx, dst);
282 PassMode::Indirect { attrs: _, extra_attrs: Some(_), on_stack: _ } => {
283 OperandValue::Ref(next(), Some(next()), self.layout.align.abi).store(bx, dst);
286 | PassMode::Indirect { attrs: _, extra_attrs: None, on_stack: _ }
287 | PassMode::Cast(_) => {
288 let next_arg = next();
289 self.store(bx, next_arg, dst);
295 impl ArgAbiMethods<'tcx> for Builder<'a, 'll, 'tcx> {
298 arg_abi: &ArgAbi<'tcx, Ty<'tcx>>,
300 dst: PlaceRef<'tcx, Self::Value>,
302 arg_abi.store_fn_arg(self, idx, dst)
306 arg_abi: &ArgAbi<'tcx, Ty<'tcx>>,
308 dst: PlaceRef<'tcx, &'ll Value>,
310 arg_abi.store(self, val, dst)
312 fn arg_memory_ty(&self, arg_abi: &ArgAbi<'tcx, Ty<'tcx>>) -> &'ll Type {
313 arg_abi.memory_ty(self)
317 pub trait FnAbiLlvmExt<'tcx> {
318 fn llvm_type(&self, cx: &CodegenCx<'ll, 'tcx>) -> &'ll Type;
319 fn ptr_to_llvm_type(&self, cx: &CodegenCx<'ll, 'tcx>) -> &'ll Type;
320 fn llvm_cconv(&self) -> llvm::CallConv;
321 fn apply_attrs_llfn(&self, cx: &CodegenCx<'ll, 'tcx>, llfn: &'ll Value);
322 fn apply_attrs_callsite(&self, bx: &mut Builder<'a, 'll, 'tcx>, callsite: &'ll Value);
325 impl<'tcx> FnAbiLlvmExt<'tcx> for FnAbi<'tcx, Ty<'tcx>> {
326 fn llvm_type(&self, cx: &CodegenCx<'ll, 'tcx>) -> &'ll Type {
327 let args_capacity: usize = self.args.iter().map(|arg|
328 if arg.pad.is_some() { 1 } else { 0 } +
329 if let PassMode::Pair(_, _) = arg.mode { 2 } else { 1 }
331 let mut llargument_tys = Vec::with_capacity(
332 if let PassMode::Indirect { .. } = self.ret.mode { 1 } else { 0 } + args_capacity,
335 let llreturn_ty = match self.ret.mode {
336 PassMode::Ignore => cx.type_void(),
337 PassMode::Direct(_) | PassMode::Pair(..) => self.ret.layout.immediate_llvm_type(cx),
338 PassMode::Cast(cast) => cast.llvm_type(cx),
339 PassMode::Indirect { .. } => {
340 llargument_tys.push(cx.type_ptr_to(self.ret.memory_ty(cx)));
345 for arg in &self.args {
347 if let Some(ty) = arg.pad {
348 llargument_tys.push(ty.llvm_type(cx));
351 let llarg_ty = match arg.mode {
352 PassMode::Ignore => continue,
353 PassMode::Direct(_) => arg.layout.immediate_llvm_type(cx),
354 PassMode::Pair(..) => {
355 llargument_tys.push(arg.layout.scalar_pair_element_llvm_type(cx, 0, true));
356 llargument_tys.push(arg.layout.scalar_pair_element_llvm_type(cx, 1, true));
359 PassMode::Indirect { attrs: _, extra_attrs: Some(_), on_stack: _ } => {
360 let ptr_ty = cx.tcx.mk_mut_ptr(arg.layout.ty);
361 let ptr_layout = cx.layout_of(ptr_ty);
362 llargument_tys.push(ptr_layout.scalar_pair_element_llvm_type(cx, 0, true));
363 llargument_tys.push(ptr_layout.scalar_pair_element_llvm_type(cx, 1, true));
366 PassMode::Cast(cast) => cast.llvm_type(cx),
367 PassMode::Indirect { attrs: _, extra_attrs: None, on_stack: _ } => {
368 cx.type_ptr_to(arg.memory_ty(cx))
371 llargument_tys.push(llarg_ty);
375 cx.type_variadic_func(&llargument_tys, llreturn_ty)
377 cx.type_func(&llargument_tys, llreturn_ty)
381 fn ptr_to_llvm_type(&self, cx: &CodegenCx<'ll, 'tcx>) -> &'ll Type {
383 llvm::LLVMPointerType(
385 cx.data_layout().instruction_address_space.0 as c_uint,
390 fn llvm_cconv(&self) -> llvm::CallConv {
392 Conv::C | Conv::Rust => llvm::CCallConv,
393 Conv::AmdGpuKernel => llvm::AmdGpuKernel,
394 Conv::AvrInterrupt => llvm::AvrInterrupt,
395 Conv::AvrNonBlockingInterrupt => llvm::AvrNonBlockingInterrupt,
396 Conv::ArmAapcs => llvm::ArmAapcsCallConv,
397 Conv::Msp430Intr => llvm::Msp430Intr,
398 Conv::PtxKernel => llvm::PtxKernel,
399 Conv::X86Fastcall => llvm::X86FastcallCallConv,
400 Conv::X86Intr => llvm::X86_Intr,
401 Conv::X86Stdcall => llvm::X86StdcallCallConv,
402 Conv::X86ThisCall => llvm::X86_ThisCall,
403 Conv::X86VectorCall => llvm::X86_VectorCall,
404 Conv::X86_64SysV => llvm::X86_64_SysV,
405 Conv::X86_64Win64 => llvm::X86_64_Win64,
409 fn apply_attrs_llfn(&self, cx: &CodegenCx<'ll, 'tcx>, llfn: &'ll Value) {
410 // FIXME(eddyb) can this also be applied to callsites?
411 if self.ret.layout.abi.is_uninhabited() {
412 llvm::Attribute::NoReturn.apply_llfn(llvm::AttributePlace::Function, llfn);
415 // FIXME(eddyb, wesleywiser): apply this to callsites as well?
416 if !self.can_unwind {
417 llvm::Attribute::NoUnwind.apply_llfn(llvm::AttributePlace::Function, llfn);
421 let mut apply = |attrs: &ArgAttributes| {
422 attrs.apply_attrs_to_llfn(llvm::AttributePlace::Argument(i), llfn);
426 match self.ret.mode {
427 PassMode::Direct(ref attrs) => {
428 attrs.apply_attrs_to_llfn(llvm::AttributePlace::ReturnValue, llfn);
430 PassMode::Indirect { ref attrs, extra_attrs: _, on_stack } => {
432 let i = apply(attrs);
433 llvm::Attribute::StructRet.apply_llfn(llvm::AttributePlace::Argument(i), llfn);
437 for arg in &self.args {
438 if arg.pad.is_some() {
439 apply(&ArgAttributes::new());
442 PassMode::Ignore => {}
443 PassMode::Indirect { ref attrs, extra_attrs: None, on_stack: true } => {
444 let i = apply(attrs);
446 llvm::LLVMRustAddByValAttr(
448 llvm::AttributePlace::Argument(i).as_uint(),
449 arg.layout.llvm_type(cx),
453 PassMode::Direct(ref attrs)
454 | PassMode::Indirect { ref attrs, extra_attrs: None, on_stack: false } => {
457 PassMode::Indirect { ref attrs, extra_attrs: Some(ref extra_attrs), on_stack } => {
462 PassMode::Pair(ref a, ref b) => {
466 PassMode::Cast(_) => {
467 apply(&ArgAttributes::new());
473 fn apply_attrs_callsite(&self, bx: &mut Builder<'a, 'll, 'tcx>, callsite: &'ll Value) {
474 // FIXME(wesleywiser, eddyb): We should apply `nounwind` and `noreturn` as appropriate to this callsite.
477 let mut apply = |attrs: &ArgAttributes| {
478 attrs.apply_attrs_to_callsite(llvm::AttributePlace::Argument(i), callsite);
482 match self.ret.mode {
483 PassMode::Direct(ref attrs) => {
484 attrs.apply_attrs_to_callsite(llvm::AttributePlace::ReturnValue, callsite);
486 PassMode::Indirect { ref attrs, extra_attrs: _, on_stack } => {
488 let i = apply(attrs);
489 llvm::Attribute::StructRet
490 .apply_callsite(llvm::AttributePlace::Argument(i), callsite);
494 if let abi::Abi::Scalar(ref scalar) = self.ret.layout.abi {
495 // If the value is a boolean, the range is 0..2 and that ultimately
496 // become 0..0 when the type becomes i1, which would be rejected
497 // by the LLVM verifier.
498 if let Int(..) = scalar.value {
499 if !scalar.is_bool() {
500 let range = scalar.valid_range_exclusive(bx);
501 if range.start != range.end {
502 bx.range_metadata(callsite, range);
507 for arg in &self.args {
508 if arg.pad.is_some() {
509 apply(&ArgAttributes::new());
512 PassMode::Ignore => {}
513 PassMode::Indirect { ref attrs, extra_attrs: None, on_stack: true } => {
514 let i = apply(attrs);
516 llvm::LLVMRustAddByValCallSiteAttr(
518 llvm::AttributePlace::Argument(i).as_uint(),
519 arg.layout.llvm_type(bx),
523 PassMode::Direct(ref attrs)
524 | PassMode::Indirect { ref attrs, extra_attrs: None, on_stack: false } => {
529 extra_attrs: Some(ref extra_attrs),
535 PassMode::Pair(ref a, ref b) => {
539 PassMode::Cast(_) => {
540 apply(&ArgAttributes::new());
545 let cconv = self.llvm_cconv();
546 if cconv != llvm::CCallConv {
547 llvm::SetInstructionCallConv(callsite, cconv);
552 impl AbiBuilderMethods<'tcx> for Builder<'a, 'll, 'tcx> {
553 fn apply_attrs_callsite(&mut self, fn_abi: &FnAbi<'tcx, Ty<'tcx>>, callsite: Self::Value) {
554 fn_abi.apply_attrs_callsite(self, callsite)
557 fn get_param(&self, index: usize) -> Self::Value {
558 llvm::get_param(self.llfn(), index as c_uint)