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Rollup merge of #128207 - folkertdev:asm-parser-generalize, r=Amanieu

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improve error message when `global_asm!` uses `asm!` options

specifically, what was

    error: expected one of `)`, `att_syntax`, or `raw`, found `preserves_flags`
      --> $DIR/bad-options.rs:45:25
       |
    LL | global_asm!("", options(preserves_flags));
       |                         ^^^^^^^^^^^^^^^ expected one of `)`, `att_syntax`, or `raw`

is now

    error: the `preserves_flags` option cannot be used with `global_asm!`
      --> $DIR/bad-options.rs:45:25
       |
    LL | global_asm!("", options(preserves_flags));
       |                         ^^^^^^^^^^^^^^^ the `preserves_flags` option is not meaningful for global-scoped inline assembly

mirroring the phrasing of the [reference](https://doc.rust-lang.org/reference/inline-assembly.html#options).

This is also a bit of a refactor for a future `naked_asm!` macro (for use in `#[naked]` functions). Currently this sort of error can come up when switching from inline to global asm, or when a user just isn't that experienced with assembly. With  `naked_asm!` added to the mix hitting this error is more likely.
This commit is contained in:
Trevor Gross
2024-07-27 13:32:56 -04:00
committed by GitHub
parent 51734a8a6d 33b5ca99b7
commit 9164dbd48c
17 changed files with 224 additions and 105 deletions
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65
compiler/rustc_builtin_macros/src/asm.rs
View File

@@ -310,6 +310,16 @@ fn err_duplicate_option(p: &Parser<'_>, symbol: Symbol, span: Span) {
p.dcx().emit_err(errors::AsmOptAlreadyprovided { span, symbol, full_span });
}
/// Report an invalid option error.
///
/// This function must be called immediately after the option token is parsed.
/// Otherwise, the suggestion will be incorrect.
fn err_unsupported_option(p: &Parser<'_>, symbol: Symbol, span: Span) {
// Tool-only output
let full_span = if p.token.kind == token::Comma { span.to(p.token.span) } else { span };
p.dcx().emit_err(errors::GlobalAsmUnsupportedOption { span, symbol, full_span });
}
/// Try to set the provided option in the provided `AsmArgs`.
/// If it is already set, report a duplicate option error.
///
@@ -318,13 +328,16 @@ fn err_duplicate_option(p: &Parser<'_>, symbol: Symbol, span: Span) {
fn try_set_option<'a>(
p: &Parser<'a>,
args: &mut AsmArgs,
is_global_asm: bool,
symbol: Symbol,
option: ast::InlineAsmOptions,
) {
if !args.options.contains(option) {
args.options |= option;
} else {
if is_global_asm && !ast::InlineAsmOptions::GLOBAL_OPTIONS.contains(option) {
err_unsupported_option(p, symbol, p.prev_token.span);
} else if args.options.contains(option) {
err_duplicate_option(p, symbol, p.prev_token.span);
} else {
args.options |= option;
}
}
@@ -338,25 +351,33 @@ fn parse_options<'a>(
p.expect(&token::OpenDelim(Delimiter::Parenthesis))?;
while !p.eat(&token::CloseDelim(Delimiter::Parenthesis)) {
if !is_global_asm && p.eat_keyword(sym::pure) {
try_set_option(p, args, sym::pure, ast::InlineAsmOptions::PURE);
} else if !is_global_asm && p.eat_keyword(sym::nomem) {
try_set_option(p, args, sym::nomem, ast::InlineAsmOptions::NOMEM);
} else if !is_global_asm && p.eat_keyword(sym::readonly) {
try_set_option(p, args, sym::readonly, ast::InlineAsmOptions::READONLY);
} else if !is_global_asm && p.eat_keyword(sym::preserves_flags) {
try_set_option(p, args, sym::preserves_flags, ast::InlineAsmOptions::PRESERVES_FLAGS);
} else if !is_global_asm && p.eat_keyword(sym::noreturn) {
try_set_option(p, args, sym::noreturn, ast::InlineAsmOptions::NORETURN);
} else if !is_global_asm && p.eat_keyword(sym::nostack) {
try_set_option(p, args, sym::nostack, ast::InlineAsmOptions::NOSTACK);
} else if !is_global_asm && p.eat_keyword(sym::may_unwind) {
try_set_option(p, args, kw::Raw, ast::InlineAsmOptions::MAY_UNWIND);
} else if p.eat_keyword(sym::att_syntax) {
try_set_option(p, args, sym::att_syntax, ast::InlineAsmOptions::ATT_SYNTAX);
} else if p.eat_keyword(kw::Raw) {
try_set_option(p, args, kw::Raw, ast::InlineAsmOptions::RAW);
} else {
const OPTIONS: [(Symbol, ast::InlineAsmOptions); ast::InlineAsmOptions::COUNT] = [
(sym::pure, ast::InlineAsmOptions::PURE),
(sym::nomem, ast::InlineAsmOptions::NOMEM),
(sym::readonly, ast::InlineAsmOptions::READONLY),
(sym::preserves_flags, ast::InlineAsmOptions::PRESERVES_FLAGS),
(sym::noreturn, ast::InlineAsmOptions::NORETURN),
(sym::nostack, ast::InlineAsmOptions::NOSTACK),
(sym::may_unwind, ast::InlineAsmOptions::MAY_UNWIND),
(sym::att_syntax, ast::InlineAsmOptions::ATT_SYNTAX),
(kw::Raw, ast::InlineAsmOptions::RAW),
];
'blk: {
for (symbol, option) in OPTIONS {
let kw_matched =
if !is_global_asm || ast::InlineAsmOptions::GLOBAL_OPTIONS.contains(option) {
p.eat_keyword(symbol)
} else {
p.eat_keyword_noexpect(symbol)
};
if kw_matched {
try_set_option(p, args, is_global_asm, symbol, option);
break 'blk;
}
}
return p.unexpected();
}