diff options
Diffstat (limited to 'compiler/rustc_parse/src/parser/asm.rs')
| -rw-r--r-- | compiler/rustc_parse/src/parser/asm.rs | 385 |
1 files changed, 385 insertions, 0 deletions
diff --git a/compiler/rustc_parse/src/parser/asm.rs b/compiler/rustc_parse/src/parser/asm.rs new file mode 100644 index 00000000000..d4d0612a317 --- /dev/null +++ b/compiler/rustc_parse/src/parser/asm.rs @@ -0,0 +1,385 @@ +use rustc_ast::ptr::P; +use rustc_ast::{self as ast, AsmMacro}; +use rustc_span::{Span, Symbol, kw}; + +use super::{ExpKeywordPair, ForceCollect, IdentIsRaw, Trailing, UsePreAttrPos}; +use crate::{PResult, Parser, errors, exp, token}; + +/// An argument to one of the `asm!` macros. The argument is syntactically valid, but is otherwise +/// not validated at all. +pub struct AsmArg { + pub kind: AsmArgKind, + pub attributes: AsmAttrVec, + pub span: Span, +} + +pub enum AsmArgKind { + Template(P<ast::Expr>), + Operand(Option<Symbol>, ast::InlineAsmOperand), + Options(Vec<AsmOption>), + ClobberAbi(Vec<(Symbol, Span)>), +} + +pub struct AsmOption { + pub symbol: Symbol, + pub span: Span, + // A bitset, with only the bit for this option's symbol set. + pub options: ast::InlineAsmOptions, + // Used when suggesting to remove an option. + pub span_with_comma: Span, +} + +/// A parsed list of attributes that is not attached to any item. +/// Used to check whether `asm!` arguments are configured out. +pub struct AsmAttrVec(pub ast::AttrVec); + +impl AsmAttrVec { + fn parse<'a>(p: &mut Parser<'a>) -> PResult<'a, Self> { + let attrs = p.parse_outer_attributes()?; + + p.collect_tokens(None, attrs, ForceCollect::No, |_, attrs| { + Ok((Self(attrs), Trailing::No, UsePreAttrPos::No)) + }) + } +} +impl ast::HasAttrs for AsmAttrVec { + // Follows `ast::Expr`. + const SUPPORTS_CUSTOM_INNER_ATTRS: bool = false; + + fn attrs(&self) -> &[rustc_ast::Attribute] { + &self.0 + } + + fn visit_attrs(&mut self, f: impl FnOnce(&mut rustc_ast::AttrVec)) { + f(&mut self.0) + } +} + +impl ast::HasTokens for AsmAttrVec { + fn tokens(&self) -> Option<&rustc_ast::tokenstream::LazyAttrTokenStream> { + None + } + + fn tokens_mut(&mut self) -> Option<&mut Option<rustc_ast::tokenstream::LazyAttrTokenStream>> { + None + } +} + +/// Used for better error messages when operand types are used that are not +/// supported by the current macro (e.g. `in` or `out` for `global_asm!`) +/// +/// returns +/// +/// - `Ok(true)` if the current token matches the keyword, and was expected +/// - `Ok(false)` if the current token does not match the keyword +/// - `Err(_)` if the current token matches the keyword, but was not expected +fn eat_operand_keyword<'a>( + p: &mut Parser<'a>, + exp: ExpKeywordPair, + asm_macro: AsmMacro, +) -> PResult<'a, bool> { + if matches!(asm_macro, AsmMacro::Asm) { + Ok(p.eat_keyword(exp)) + } else { + let span = p.token.span; + if p.eat_keyword_noexpect(exp.kw) { + // in gets printed as `r#in` otherwise + let symbol = if exp.kw == kw::In { "in" } else { exp.kw.as_str() }; + Err(p.dcx().create_err(errors::AsmUnsupportedOperand { + span, + symbol, + macro_name: asm_macro.macro_name(), + })) + } else { + Ok(false) + } + } +} + +fn parse_asm_operand<'a>( + p: &mut Parser<'a>, + asm_macro: AsmMacro, +) -> PResult<'a, Option<ast::InlineAsmOperand>> { + let dcx = p.dcx(); + + Ok(Some(if eat_operand_keyword(p, exp!(In), asm_macro)? { + let reg = parse_reg(p)?; + if p.eat_keyword(exp!(Underscore)) { + let err = dcx.create_err(errors::AsmUnderscoreInput { span: p.token.span }); + return Err(err); + } + let expr = p.parse_expr()?; + ast::InlineAsmOperand::In { reg, expr } + } else if eat_operand_keyword(p, exp!(Out), asm_macro)? { + let reg = parse_reg(p)?; + let expr = if p.eat_keyword(exp!(Underscore)) { None } else { Some(p.parse_expr()?) }; + ast::InlineAsmOperand::Out { reg, expr, late: false } + } else if eat_operand_keyword(p, exp!(Lateout), asm_macro)? { + let reg = parse_reg(p)?; + let expr = if p.eat_keyword(exp!(Underscore)) { None } else { Some(p.parse_expr()?) }; + ast::InlineAsmOperand::Out { reg, expr, late: true } + } else if eat_operand_keyword(p, exp!(Inout), asm_macro)? { + let reg = parse_reg(p)?; + if p.eat_keyword(exp!(Underscore)) { + let err = dcx.create_err(errors::AsmUnderscoreInput { span: p.token.span }); + return Err(err); + } + let expr = p.parse_expr()?; + if p.eat(exp!(FatArrow)) { + let out_expr = + if p.eat_keyword(exp!(Underscore)) { None } else { Some(p.parse_expr()?) }; + ast::InlineAsmOperand::SplitInOut { reg, in_expr: expr, out_expr, late: false } + } else { + ast::InlineAsmOperand::InOut { reg, expr, late: false } + } + } else if eat_operand_keyword(p, exp!(Inlateout), asm_macro)? { + let reg = parse_reg(p)?; + if p.eat_keyword(exp!(Underscore)) { + let err = dcx.create_err(errors::AsmUnderscoreInput { span: p.token.span }); + return Err(err); + } + let expr = p.parse_expr()?; + if p.eat(exp!(FatArrow)) { + let out_expr = + if p.eat_keyword(exp!(Underscore)) { None } else { Some(p.parse_expr()?) }; + ast::InlineAsmOperand::SplitInOut { reg, in_expr: expr, out_expr, late: true } + } else { + ast::InlineAsmOperand::InOut { reg, expr, late: true } + } + } else if eat_operand_keyword(p, exp!(Label), asm_macro)? { + let block = p.parse_block()?; + ast::InlineAsmOperand::Label { block } + } else if p.eat_keyword(exp!(Const)) { + let anon_const = p.parse_expr_anon_const()?; + ast::InlineAsmOperand::Const { anon_const } + } else if p.eat_keyword(exp!(Sym)) { + let expr = p.parse_expr()?; + let ast::ExprKind::Path(qself, path) = &expr.kind else { + let err = dcx.create_err(errors::AsmSymNoPath { span: expr.span }); + return Err(err); + }; + let sym = + ast::InlineAsmSym { id: ast::DUMMY_NODE_ID, qself: qself.clone(), path: path.clone() }; + ast::InlineAsmOperand::Sym { sym } + } else { + return Ok(None); + })) +} + +// Public for rustfmt. +pub fn parse_asm_args<'a>( + p: &mut Parser<'a>, + sp: Span, + asm_macro: AsmMacro, +) -> PResult<'a, Vec<AsmArg>> { + let dcx = p.dcx(); + + if p.token == token::Eof { + return Err(dcx.create_err(errors::AsmRequiresTemplate { span: sp })); + } + + let mut args = Vec::new(); + + let attributes = AsmAttrVec::parse(p)?; + let first_template = p.parse_expr()?; + args.push(AsmArg { + span: first_template.span, + kind: AsmArgKind::Template(first_template), + attributes, + }); + + let mut allow_templates = true; + + while p.token != token::Eof { + if !p.eat(exp!(Comma)) { + if allow_templates { + // After a template string, we always expect *only* a comma... + return Err(dcx.create_err(errors::AsmExpectedComma { span: p.token.span })); + } else { + // ...after that delegate to `expect` to also include the other expected tokens. + return Err(p.expect(exp!(Comma)).err().unwrap()); + } + } + + // Accept trailing commas. + if p.token == token::Eof { + break; + } + + let attributes = AsmAttrVec::parse(p)?; + let span_start = p.token.span; + + // Parse `clobber_abi`. + if p.eat_keyword(exp!(ClobberAbi)) { + allow_templates = false; + + args.push(AsmArg { + kind: AsmArgKind::ClobberAbi(parse_clobber_abi(p)?), + span: span_start.to(p.prev_token.span), + attributes, + }); + + continue; + } + + // Parse `options`. + if p.eat_keyword(exp!(Options)) { + allow_templates = false; + + args.push(AsmArg { + kind: AsmArgKind::Options(parse_options(p, asm_macro)?), + span: span_start.to(p.prev_token.span), + attributes, + }); + + continue; + } + + // Parse operand names. + let name = if p.token.is_ident() && p.look_ahead(1, |t| *t == token::Eq) { + let (ident, _) = p.token.ident().unwrap(); + p.bump(); + p.expect(exp!(Eq))?; + allow_templates = false; + Some(ident.name) + } else { + None + }; + + if let Some(op) = parse_asm_operand(p, asm_macro)? { + allow_templates = false; + + args.push(AsmArg { + span: span_start.to(p.prev_token.span), + kind: AsmArgKind::Operand(name, op), + attributes, + }); + } else if allow_templates { + let template = p.parse_expr()?; + // If it can't possibly expand to a string, provide diagnostics here to include other + // things it could have been. + match template.kind { + ast::ExprKind::Lit(token_lit) + if matches!( + token_lit.kind, + token::LitKind::Str | token::LitKind::StrRaw(_) + ) => {} + ast::ExprKind::MacCall(..) => {} + _ => { + let err = dcx.create_err(errors::AsmExpectedOther { + span: template.span, + is_inline_asm: matches!(asm_macro, AsmMacro::Asm), + }); + return Err(err); + } + } + + args.push(AsmArg { + span: template.span, + kind: AsmArgKind::Template(template), + attributes, + }); + } else { + p.unexpected_any()? + } + } + + Ok(args) +} + +fn parse_options<'a>(p: &mut Parser<'a>, asm_macro: AsmMacro) -> PResult<'a, Vec<AsmOption>> { + p.expect(exp!(OpenParen))?; + + let mut asm_options = Vec::new(); + + while !p.eat(exp!(CloseParen)) { + const OPTIONS: [(ExpKeywordPair, ast::InlineAsmOptions); ast::InlineAsmOptions::COUNT] = [ + (exp!(Pure), ast::InlineAsmOptions::PURE), + (exp!(Nomem), ast::InlineAsmOptions::NOMEM), + (exp!(Readonly), ast::InlineAsmOptions::READONLY), + (exp!(PreservesFlags), ast::InlineAsmOptions::PRESERVES_FLAGS), + (exp!(Noreturn), ast::InlineAsmOptions::NORETURN), + (exp!(Nostack), ast::InlineAsmOptions::NOSTACK), + (exp!(MayUnwind), ast::InlineAsmOptions::MAY_UNWIND), + (exp!(AttSyntax), ast::InlineAsmOptions::ATT_SYNTAX), + (exp!(Raw), ast::InlineAsmOptions::RAW), + ]; + + 'blk: { + for (exp, options) in OPTIONS { + // Gives a more accurate list of expected next tokens. + let kw_matched = if asm_macro.is_supported_option(options) { + p.eat_keyword(exp) + } else { + p.eat_keyword_noexpect(exp.kw) + }; + + if kw_matched { + let span = p.prev_token.span; + let span_with_comma = + if p.token == token::Comma { span.to(p.token.span) } else { span }; + + asm_options.push(AsmOption { symbol: exp.kw, span, options, span_with_comma }); + break 'blk; + } + } + + return p.unexpected_any(); + } + + // Allow trailing commas. + if p.eat(exp!(CloseParen)) { + break; + } + p.expect(exp!(Comma))?; + } + + Ok(asm_options) +} + +fn parse_clobber_abi<'a>(p: &mut Parser<'a>) -> PResult<'a, Vec<(Symbol, Span)>> { + p.expect(exp!(OpenParen))?; + + if p.eat(exp!(CloseParen)) { + return Err(p.dcx().create_err(errors::NonABI { span: p.token.span })); + } + + let mut new_abis = Vec::new(); + while !p.eat(exp!(CloseParen)) { + match p.parse_str_lit() { + Ok(str_lit) => { + new_abis.push((str_lit.symbol_unescaped, str_lit.span)); + } + Err(opt_lit) => { + let span = opt_lit.map_or(p.token.span, |lit| lit.span); + return Err(p.dcx().create_err(errors::AsmExpectedStringLiteral { span })); + } + }; + + // Allow trailing commas + if p.eat(exp!(CloseParen)) { + break; + } + p.expect(exp!(Comma))?; + } + + Ok(new_abis) +} + +fn parse_reg<'a>(p: &mut Parser<'a>) -> PResult<'a, ast::InlineAsmRegOrRegClass> { + p.expect(exp!(OpenParen))?; + let result = match p.token.uninterpolate().kind { + token::Ident(name, IdentIsRaw::No) => ast::InlineAsmRegOrRegClass::RegClass(name), + token::Literal(token::Lit { kind: token::LitKind::Str, symbol, suffix: _ }) => { + ast::InlineAsmRegOrRegClass::Reg(symbol) + } + _ => { + return Err(p.dcx().create_err(errors::ExpectedRegisterClassOrExplicitRegister { + span: p.token.span, + })); + } + }; + p.bump(); + p.expect(exp!(CloseParen))?; + Ok(result) +} |