| use crate::{ImplTraitContext, ImplTraitPosition, ParamMode, ResolverAstLoweringExt}; |
| |
| use super::errors::{ |
| AbiSpecifiedMultipleTimes, AttSyntaxOnlyX86, ClobberAbiNotSupported, |
| InlineAsmUnsupportedTarget, InvalidAbiClobberAbi, InvalidAsmTemplateModifierConst, |
| InvalidAsmTemplateModifierRegClass, InvalidAsmTemplateModifierRegClassSub, |
| InvalidAsmTemplateModifierSym, InvalidRegister, InvalidRegisterClass, RegisterClassOnlyClobber, |
| RegisterConflict, |
| }; |
| use super::LoweringContext; |
| |
| use rustc_ast::ptr::P; |
| use rustc_ast::*; |
| use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap}; |
| use rustc_hir as hir; |
| use rustc_hir::def::{DefKind, Res}; |
| use rustc_hir::definitions::DefPathData; |
| use rustc_session::parse::feature_err; |
| use rustc_span::{sym, Span}; |
| use rustc_target::asm; |
| use std::collections::hash_map::Entry; |
| use std::fmt::Write; |
| |
| impl<'a, 'hir> LoweringContext<'a, 'hir> { |
| pub(crate) fn lower_inline_asm( |
| &mut self, |
| sp: Span, |
| asm: &InlineAsm, |
| ) -> &'hir hir::InlineAsm<'hir> { |
| // Rustdoc needs to support asm! from foreign architectures: don't try |
| // lowering the register constraints in this case. |
| let asm_arch = |
| if self.tcx.sess.opts.actually_rustdoc { None } else { self.tcx.sess.asm_arch }; |
| if asm_arch.is_none() && !self.tcx.sess.opts.actually_rustdoc { |
| self.tcx.sess.emit_err(InlineAsmUnsupportedTarget { span: sp }); |
| } |
| if let Some(asm_arch) = asm_arch { |
| // Inline assembly is currently only stable for these architectures. |
| let is_stable = matches!( |
| asm_arch, |
| asm::InlineAsmArch::X86 |
| | asm::InlineAsmArch::X86_64 |
| | asm::InlineAsmArch::Arm |
| | asm::InlineAsmArch::AArch64 |
| | asm::InlineAsmArch::RiscV32 |
| | asm::InlineAsmArch::RiscV64 |
| | asm::InlineAsmArch::LoongArch64 |
| ); |
| if !is_stable && !self.tcx.features().asm_experimental_arch { |
| feature_err( |
| &self.tcx.sess.parse_sess, |
| sym::asm_experimental_arch, |
| sp, |
| "inline assembly is not stable yet on this architecture", |
| ) |
| .emit(); |
| } |
| } |
| if asm.options.contains(InlineAsmOptions::ATT_SYNTAX) |
| && !matches!(asm_arch, Some(asm::InlineAsmArch::X86 | asm::InlineAsmArch::X86_64)) |
| && !self.tcx.sess.opts.actually_rustdoc |
| { |
| self.tcx.sess.emit_err(AttSyntaxOnlyX86 { span: sp }); |
| } |
| if asm.options.contains(InlineAsmOptions::MAY_UNWIND) && !self.tcx.features().asm_unwind { |
| feature_err( |
| &self.tcx.sess.parse_sess, |
| sym::asm_unwind, |
| sp, |
| "the `may_unwind` option is unstable", |
| ) |
| .emit(); |
| } |
| |
| let mut clobber_abis = FxIndexMap::default(); |
| if let Some(asm_arch) = asm_arch { |
| for (abi_name, abi_span) in &asm.clobber_abis { |
| match asm::InlineAsmClobberAbi::parse(asm_arch, &self.tcx.sess.target, *abi_name) { |
| Ok(abi) => { |
| // If the abi was already in the list, emit an error |
| match clobber_abis.get(&abi) { |
| Some((prev_name, prev_sp)) => { |
| // Multiple different abi names may actually be the same ABI |
| // If the specified ABIs are not the same name, alert the user that they resolve to the same ABI |
| let source_map = self.tcx.sess.source_map(); |
| let equivalent = (source_map.span_to_snippet(*prev_sp) |
| != source_map.span_to_snippet(*abi_span)) |
| .then_some(()); |
| |
| self.tcx.sess.emit_err(AbiSpecifiedMultipleTimes { |
| abi_span: *abi_span, |
| prev_name: *prev_name, |
| prev_span: *prev_sp, |
| equivalent, |
| }); |
| } |
| None => { |
| clobber_abis.insert(abi, (*abi_name, *abi_span)); |
| } |
| } |
| } |
| Err(&[]) => { |
| self.tcx.sess.emit_err(ClobberAbiNotSupported { abi_span: *abi_span }); |
| } |
| Err(supported_abis) => { |
| let mut abis = format!("`{}`", supported_abis[0]); |
| for m in &supported_abis[1..] { |
| let _ = write!(abis, ", `{m}`"); |
| } |
| self.tcx.sess.emit_err(InvalidAbiClobberAbi { |
| abi_span: *abi_span, |
| supported_abis: abis, |
| }); |
| } |
| } |
| } |
| } |
| |
| // Lower operands to HIR. We use dummy register classes if an error |
| // occurs during lowering because we still need to be able to produce a |
| // valid HIR. |
| let sess = self.tcx.sess; |
| let mut operands: Vec<_> = asm |
| .operands |
| .iter() |
| .map(|(op, op_sp)| { |
| let lower_reg = |®: &_| match reg { |
| InlineAsmRegOrRegClass::Reg(reg) => { |
| asm::InlineAsmRegOrRegClass::Reg(if let Some(asm_arch) = asm_arch { |
| asm::InlineAsmReg::parse(asm_arch, reg).unwrap_or_else(|error| { |
| sess.emit_err(InvalidRegister { op_span: *op_sp, reg, error }); |
| asm::InlineAsmReg::Err |
| }) |
| } else { |
| asm::InlineAsmReg::Err |
| }) |
| } |
| InlineAsmRegOrRegClass::RegClass(reg_class) => { |
| asm::InlineAsmRegOrRegClass::RegClass(if let Some(asm_arch) = asm_arch { |
| asm::InlineAsmRegClass::parse(asm_arch, reg_class).unwrap_or_else( |
| |error| { |
| sess.emit_err(InvalidRegisterClass { |
| op_span: *op_sp, |
| reg_class, |
| error, |
| }); |
| asm::InlineAsmRegClass::Err |
| }, |
| ) |
| } else { |
| asm::InlineAsmRegClass::Err |
| }) |
| } |
| }; |
| |
| let op = match op { |
| InlineAsmOperand::In { reg, expr } => hir::InlineAsmOperand::In { |
| reg: lower_reg(reg), |
| expr: self.lower_expr(expr), |
| }, |
| InlineAsmOperand::Out { reg, late, expr } => hir::InlineAsmOperand::Out { |
| reg: lower_reg(reg), |
| late: *late, |
| expr: expr.as_ref().map(|expr| self.lower_expr(expr)), |
| }, |
| InlineAsmOperand::InOut { reg, late, expr } => hir::InlineAsmOperand::InOut { |
| reg: lower_reg(reg), |
| late: *late, |
| expr: self.lower_expr(expr), |
| }, |
| InlineAsmOperand::SplitInOut { reg, late, in_expr, out_expr } => { |
| hir::InlineAsmOperand::SplitInOut { |
| reg: lower_reg(reg), |
| late: *late, |
| in_expr: self.lower_expr(in_expr), |
| out_expr: out_expr.as_ref().map(|expr| self.lower_expr(expr)), |
| } |
| } |
| InlineAsmOperand::Const { anon_const } => { |
| if !self.tcx.features().asm_const { |
| feature_err( |
| &sess.parse_sess, |
| sym::asm_const, |
| *op_sp, |
| "const operands for inline assembly are unstable", |
| ) |
| .emit(); |
| } |
| hir::InlineAsmOperand::Const { |
| anon_const: self.lower_anon_const(anon_const), |
| } |
| } |
| InlineAsmOperand::Sym { sym } => { |
| let static_def_id = self |
| .resolver |
| .get_partial_res(sym.id) |
| .and_then(|res| res.full_res()) |
| .and_then(|res| match res { |
| Res::Def(DefKind::Static(_), def_id) => Some(def_id), |
| _ => None, |
| }); |
| |
| if let Some(def_id) = static_def_id { |
| let path = self.lower_qpath( |
| sym.id, |
| &sym.qself, |
| &sym.path, |
| ParamMode::Optional, |
| &ImplTraitContext::Disallowed(ImplTraitPosition::Path), |
| None, |
| ); |
| hir::InlineAsmOperand::SymStatic { path, def_id } |
| } else { |
| // Replace the InlineAsmSym AST node with an |
| // Expr using the name node id. |
| let expr = Expr { |
| id: sym.id, |
| kind: ExprKind::Path(sym.qself.clone(), sym.path.clone()), |
| span: *op_sp, |
| attrs: AttrVec::new(), |
| tokens: None, |
| }; |
| |
| // Wrap the expression in an AnonConst. |
| let parent_def_id = self.current_hir_id_owner; |
| let node_id = self.next_node_id(); |
| self.create_def( |
| parent_def_id.def_id, |
| node_id, |
| DefPathData::AnonConst, |
| *op_sp, |
| ); |
| let anon_const = AnonConst { id: node_id, value: P(expr) }; |
| hir::InlineAsmOperand::SymFn { |
| anon_const: self.lower_anon_const(&anon_const), |
| } |
| } |
| } |
| }; |
| (op, self.lower_span(*op_sp)) |
| }) |
| .collect(); |
| |
| // Validate template modifiers against the register classes for the operands |
| for p in &asm.template { |
| if let InlineAsmTemplatePiece::Placeholder { |
| operand_idx, |
| modifier: Some(modifier), |
| span: placeholder_span, |
| } = *p |
| { |
| let op_sp = asm.operands[operand_idx].1; |
| match &operands[operand_idx].0 { |
| hir::InlineAsmOperand::In { reg, .. } |
| | hir::InlineAsmOperand::Out { reg, .. } |
| | hir::InlineAsmOperand::InOut { reg, .. } |
| | hir::InlineAsmOperand::SplitInOut { reg, .. } => { |
| let class = reg.reg_class(); |
| if class == asm::InlineAsmRegClass::Err { |
| continue; |
| } |
| let valid_modifiers = class.valid_modifiers(asm_arch.unwrap()); |
| if !valid_modifiers.contains(&modifier) { |
| let sub = if !valid_modifiers.is_empty() { |
| let mut mods = format!("`{}`", valid_modifiers[0]); |
| for m in &valid_modifiers[1..] { |
| let _ = write!(mods, ", `{m}`"); |
| } |
| InvalidAsmTemplateModifierRegClassSub::SupportModifier { |
| class_name: class.name(), |
| modifiers: mods, |
| } |
| } else { |
| InvalidAsmTemplateModifierRegClassSub::DoesNotSupportModifier { |
| class_name: class.name(), |
| } |
| }; |
| sess.emit_err(InvalidAsmTemplateModifierRegClass { |
| placeholder_span, |
| op_span: op_sp, |
| sub, |
| }); |
| } |
| } |
| hir::InlineAsmOperand::Const { .. } => { |
| sess.emit_err(InvalidAsmTemplateModifierConst { |
| placeholder_span, |
| op_span: op_sp, |
| }); |
| } |
| hir::InlineAsmOperand::SymFn { .. } |
| | hir::InlineAsmOperand::SymStatic { .. } => { |
| sess.emit_err(InvalidAsmTemplateModifierSym { |
| placeholder_span, |
| op_span: op_sp, |
| }); |
| } |
| } |
| } |
| } |
| |
| let mut used_input_regs = FxHashMap::default(); |
| let mut used_output_regs = FxHashMap::default(); |
| |
| for (idx, &(ref op, op_sp)) in operands.iter().enumerate() { |
| if let Some(reg) = op.reg() { |
| let reg_class = reg.reg_class(); |
| if reg_class == asm::InlineAsmRegClass::Err { |
| continue; |
| } |
| |
| // Some register classes can only be used as clobbers. This |
| // means that we disallow passing a value in/out of the asm and |
| // require that the operand name an explicit register, not a |
| // register class. |
| if reg_class.is_clobber_only(asm_arch.unwrap()) && !op.is_clobber() { |
| sess.emit_err(RegisterClassOnlyClobber { |
| op_span: op_sp, |
| reg_class_name: reg_class.name(), |
| }); |
| continue; |
| } |
| |
| // Check for conflicts between explicit register operands. |
| if let asm::InlineAsmRegOrRegClass::Reg(reg) = reg { |
| let (input, output) = match op { |
| hir::InlineAsmOperand::In { .. } => (true, false), |
| |
| // Late output do not conflict with inputs, but normal outputs do |
| hir::InlineAsmOperand::Out { late, .. } => (!late, true), |
| |
| hir::InlineAsmOperand::InOut { .. } |
| | hir::InlineAsmOperand::SplitInOut { .. } => (true, true), |
| |
| hir::InlineAsmOperand::Const { .. } |
| | hir::InlineAsmOperand::SymFn { .. } |
| | hir::InlineAsmOperand::SymStatic { .. } => { |
| unreachable!() |
| } |
| }; |
| |
| // Flag to output the error only once per operand |
| let mut skip = false; |
| reg.overlapping_regs(|r| { |
| let mut check = |used_regs: &mut FxHashMap<asm::InlineAsmReg, usize>, |
| input| { |
| match used_regs.entry(r) { |
| Entry::Occupied(o) => { |
| if skip { |
| return; |
| } |
| skip = true; |
| |
| let idx2 = *o.get(); |
| let (ref op2, op_sp2) = operands[idx2]; |
| let Some(asm::InlineAsmRegOrRegClass::Reg(reg2)) = op2.reg() |
| else { |
| unreachable!(); |
| }; |
| |
| let in_out = match (op, op2) { |
| ( |
| hir::InlineAsmOperand::In { .. }, |
| hir::InlineAsmOperand::Out { late, .. }, |
| ) |
| | ( |
| hir::InlineAsmOperand::Out { late, .. }, |
| hir::InlineAsmOperand::In { .. }, |
| ) => { |
| assert!(!*late); |
| let out_op_sp = if input { op_sp2 } else { op_sp }; |
| Some(out_op_sp) |
| } |
| _ => None, |
| }; |
| |
| sess.emit_err(RegisterConflict { |
| op_span1: op_sp, |
| op_span2: op_sp2, |
| reg1_name: reg.name(), |
| reg2_name: reg2.name(), |
| in_out, |
| }); |
| } |
| Entry::Vacant(v) => { |
| if r == reg { |
| v.insert(idx); |
| } |
| } |
| } |
| }; |
| if input { |
| check(&mut used_input_regs, true); |
| } |
| if output { |
| check(&mut used_output_regs, false); |
| } |
| }); |
| } |
| } |
| } |
| |
| // If a clobber_abi is specified, add the necessary clobbers to the |
| // operands list. |
| let mut clobbered = FxHashSet::default(); |
| for (abi, (_, abi_span)) in clobber_abis { |
| for &clobber in abi.clobbered_regs() { |
| // Don't emit a clobber for a register already clobbered |
| if clobbered.contains(&clobber) { |
| continue; |
| } |
| |
| let mut output_used = false; |
| clobber.overlapping_regs(|reg| { |
| if used_output_regs.contains_key(®) { |
| output_used = true; |
| } |
| }); |
| |
| if !output_used { |
| operands.push(( |
| hir::InlineAsmOperand::Out { |
| reg: asm::InlineAsmRegOrRegClass::Reg(clobber), |
| late: true, |
| expr: None, |
| }, |
| self.lower_span(abi_span), |
| )); |
| clobbered.insert(clobber); |
| } |
| } |
| } |
| |
| let operands = self.arena.alloc_from_iter(operands); |
| let template = self.arena.alloc_from_iter(asm.template.iter().cloned()); |
| let template_strs = self.arena.alloc_from_iter( |
| asm.template_strs |
| .iter() |
| .map(|(sym, snippet, span)| (*sym, *snippet, self.lower_span(*span))), |
| ); |
| let line_spans = |
| self.arena.alloc_from_iter(asm.line_spans.iter().map(|span| self.lower_span(*span))); |
| let hir_asm = |
| hir::InlineAsm { template, template_strs, operands, options: asm.options, line_spans }; |
| self.arena.alloc(hir_asm) |
| } |
| } |
