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Rollup merge of #92016 - calebcartwright:expose-asm-args-parsing, r=A…
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…manieu

builtin_macros: allow external consumers for AsmArgs parsing

As discussed in Zulip (https://rust-lang.zulipchat.com/#narrow/stream/131828-t-compiler/topic/parsing.20of.20AsmArgs.20for.20inline.20assembly), we need a function entry point that rustfmt can leverage from a pre-expansion context to get a more structured representation of the asm args without having to duplicate/maintain the token stream parsing

r? ```@Amanieu``` and/or ```@joshtriplett```
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@matthiaskrgr
matthiaskrgr committed Dec 18, 2021
2 parents 816cda7 + 78a8e00 commit fd445dd
Showing 1 changed file with 43 additions and 29 deletions.
72 changes: 43 additions & 29 deletions compiler/rustc_builtin_macros/src/asm.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -8,13 +8,14 @@ use rustc_expand::base::{self, *};
use rustc_parse::parser::Parser;
use rustc_parse_format as parse;
use rustc_session::lint;
use rustc_session::parse::ParseSess;
use rustc_span::symbol::Ident;
use rustc_span::symbol::{kw, sym, Symbol};
use rustc_span::{InnerSpan, Span};
use rustc_target::asm::InlineAsmArch;
use smallvec::smallvec;

struct AsmArgs {
pub struct AsmArgs {
templates: Vec<P<ast::Expr>>,
operands: Vec<(ast::InlineAsmOperand, Span)>,
named_args: FxHashMap<Symbol, usize>,
Expand All @@ -31,15 +32,28 @@ fn parse_args<'a>(
is_global_asm: bool,
) -> Result<AsmArgs, DiagnosticBuilder<'a>> {
let mut p = ecx.new_parser_from_tts(tts);
let sess = &ecx.sess.parse_sess;
parse_asm_args(&mut p, sess, sp, is_global_asm)
}

// Primarily public for rustfmt consumption.
// Internal consumers should continue to leverage `expand_asm`/`expand__global_asm`
pub fn parse_asm_args<'a>(
p: &mut Parser<'a>,
sess: &'a ParseSess,
sp: Span,
is_global_asm: bool,
) -> Result<AsmArgs, DiagnosticBuilder<'a>> {
let diag = &sess.span_diagnostic;

if p.token == token::Eof {
return Err(ecx.struct_span_err(sp, "requires at least a template string argument"));
return Err(diag.struct_span_err(sp, "requires at least a template string argument"));
}

// Detect use of the legacy llvm_asm! syntax (which used to be called asm!)
if !is_global_asm && p.look_ahead(1, |t| *t == token::Colon || *t == token::ModSep) {
let mut err =
ecx.struct_span_err(sp, "the legacy LLVM-style asm! syntax is no longer supported");
diag.struct_span_err(sp, "the legacy LLVM-style asm! syntax is no longer supported");
err.note("consider migrating to the new asm! syntax specified in RFC 2873");
err.note("alternatively, switch to llvm_asm! to keep your code working as it is");
return Err(err);
Expand All @@ -61,7 +75,7 @@ fn parse_args<'a>(
if !p.eat(&token::Comma) {
if allow_templates {
// After a template string, we always expect *only* a comma...
let mut err = ecx.struct_span_err(p.token.span, "expected token: `,`");
let mut err = diag.struct_span_err(p.token.span, "expected token: `,`");
err.span_label(p.token.span, "expected `,`");
p.maybe_annotate_with_ascription(&mut err, false);
return Err(err);
Expand All @@ -76,14 +90,14 @@ fn parse_args<'a>(

// Parse clobber_abi
if p.eat_keyword(sym::clobber_abi) {
parse_clobber_abi(&mut p, &mut args)?;
parse_clobber_abi(p, &mut args)?;
allow_templates = false;
continue;
}

// Parse options
if p.eat_keyword(sym::options) {
parse_options(&mut p, &mut args, is_global_asm)?;
parse_options(p, &mut args, is_global_asm)?;
allow_templates = false;
continue;
}
Expand All @@ -103,25 +117,25 @@ fn parse_args<'a>(

let mut explicit_reg = false;
let op = if !is_global_asm && p.eat_keyword(kw::In) {
let reg = parse_reg(&mut p, &mut explicit_reg)?;
let reg = parse_reg(p, &mut explicit_reg)?;
if p.eat_keyword(kw::Underscore) {
let err = ecx.struct_span_err(p.token.span, "_ cannot be used for input operands");
let err = diag.struct_span_err(p.token.span, "_ cannot be used for input operands");
return Err(err);
}
let expr = p.parse_expr()?;
ast::InlineAsmOperand::In { reg, expr }
} else if !is_global_asm && p.eat_keyword(sym::out) {
let reg = parse_reg(&mut p, &mut explicit_reg)?;
let reg = parse_reg(p, &mut explicit_reg)?;
let expr = if p.eat_keyword(kw::Underscore) { None } else { Some(p.parse_expr()?) };
ast::InlineAsmOperand::Out { reg, expr, late: false }
} else if !is_global_asm && p.eat_keyword(sym::lateout) {
let reg = parse_reg(&mut p, &mut explicit_reg)?;
let reg = parse_reg(p, &mut explicit_reg)?;
let expr = if p.eat_keyword(kw::Underscore) { None } else { Some(p.parse_expr()?) };
ast::InlineAsmOperand::Out { reg, expr, late: true }
} else if !is_global_asm && p.eat_keyword(sym::inout) {
let reg = parse_reg(&mut p, &mut explicit_reg)?;
let reg = parse_reg(p, &mut explicit_reg)?;
if p.eat_keyword(kw::Underscore) {
let err = ecx.struct_span_err(p.token.span, "_ cannot be used for input operands");
let err = diag.struct_span_err(p.token.span, "_ cannot be used for input operands");
return Err(err);
}
let expr = p.parse_expr()?;
Expand All @@ -133,9 +147,9 @@ fn parse_args<'a>(
ast::InlineAsmOperand::InOut { reg, expr, late: false }
}
} else if !is_global_asm && p.eat_keyword(sym::inlateout) {
let reg = parse_reg(&mut p, &mut explicit_reg)?;
let reg = parse_reg(p, &mut explicit_reg)?;
if p.eat_keyword(kw::Underscore) {
let err = ecx.struct_span_err(p.token.span, "_ cannot be used for input operands");
let err = diag.struct_span_err(p.token.span, "_ cannot be used for input operands");
return Err(err);
}
let expr = p.parse_expr()?;
Expand All @@ -154,7 +168,7 @@ fn parse_args<'a>(
match expr.kind {
ast::ExprKind::Path(..) => {}
_ => {
let err = ecx
let err = diag
.struct_span_err(expr.span, "argument to `sym` must be a path expression");
return Err(err);
}
Expand All @@ -173,7 +187,7 @@ fn parse_args<'a>(
} else {
"expected operand, clobber_abi, options, or additional template string"
};
let mut err = ecx.struct_span_err(template.span, errstr);
let mut err = diag.struct_span_err(template.span, errstr);
err.span_label(template.span, errstr);
return Err(err);
}
Expand All @@ -193,31 +207,31 @@ fn parse_args<'a>(
// clobber_abi/options. We do this at the end once we have the full span
// of the argument available.
if !args.options_spans.is_empty() {
ecx.struct_span_err(span, "arguments are not allowed after options")
diag.struct_span_err(span, "arguments are not allowed after options")
.span_labels(args.options_spans.clone(), "previous options")
.span_label(span, "argument")
.emit();
} else if let Some((_, abi_span)) = args.clobber_abis.last() {
ecx.struct_span_err(span, "arguments are not allowed after clobber_abi")
diag.struct_span_err(span, "arguments are not allowed after clobber_abi")
.span_label(*abi_span, "clobber_abi")
.span_label(span, "argument")
.emit();
}
if explicit_reg {
if name.is_some() {
ecx.struct_span_err(span, "explicit register arguments cannot have names").emit();
diag.struct_span_err(span, "explicit register arguments cannot have names").emit();
}
args.reg_args.insert(slot);
} else if let Some(name) = name {
if let Some(&prev) = args.named_args.get(&name) {
ecx.struct_span_err(span, &format!("duplicate argument named `{}`", name))
diag.struct_span_err(span, &format!("duplicate argument named `{}`", name))
.span_label(args.operands[prev].1, "previously here")
.span_label(span, "duplicate argument")
.emit();
continue;
}
if !args.reg_args.is_empty() {
let mut err = ecx.struct_span_err(
let mut err = diag.struct_span_err(
span,
"named arguments cannot follow explicit register arguments",
);
Expand All @@ -230,7 +244,7 @@ fn parse_args<'a>(
args.named_args.insert(name, slot);
} else {
if !args.named_args.is_empty() || !args.reg_args.is_empty() {
let mut err = ecx.struct_span_err(
let mut err = diag.struct_span_err(
span,
"positional arguments cannot follow named arguments \
or explicit register arguments",
Expand All @@ -251,21 +265,21 @@ fn parse_args<'a>(
&& args.options.contains(ast::InlineAsmOptions::READONLY)
{
let spans = args.options_spans.clone();
ecx.struct_span_err(spans, "the `nomem` and `readonly` options are mutually exclusive")
diag.struct_span_err(spans, "the `nomem` and `readonly` options are mutually exclusive")
.emit();
}
if args.options.contains(ast::InlineAsmOptions::PURE)
&& args.options.contains(ast::InlineAsmOptions::NORETURN)
{
let spans = args.options_spans.clone();
ecx.struct_span_err(spans, "the `pure` and `noreturn` options are mutually exclusive")
diag.struct_span_err(spans, "the `pure` and `noreturn` options are mutually exclusive")
.emit();
}
if args.options.contains(ast::InlineAsmOptions::PURE)
&& !args.options.intersects(ast::InlineAsmOptions::NOMEM | ast::InlineAsmOptions::READONLY)
{
let spans = args.options_spans.clone();
ecx.struct_span_err(
diag.struct_span_err(
spans,
"the `pure` option must be combined with either `nomem` or `readonly`",
)
Expand Down Expand Up @@ -296,14 +310,14 @@ fn parse_args<'a>(
}
}
if args.options.contains(ast::InlineAsmOptions::PURE) && !have_real_output {
ecx.struct_span_err(
diag.struct_span_err(
args.options_spans.clone(),
"asm with the `pure` option must have at least one output",
)
.emit();
}
if args.options.contains(ast::InlineAsmOptions::NORETURN) && !outputs_sp.is_empty() {
let err = ecx
let err = diag
.struct_span_err(outputs_sp, "asm outputs are not allowed with the `noreturn` option");

// Bail out now since this is likely to confuse MIR
Expand All @@ -312,7 +326,7 @@ fn parse_args<'a>(

if args.clobber_abis.len() > 0 {
if is_global_asm {
let err = ecx.struct_span_err(
let err = diag.struct_span_err(
args.clobber_abis.iter().map(|(_, span)| *span).collect::<Vec<Span>>(),
"`clobber_abi` cannot be used with `global_asm!`",
);
Expand All @@ -321,7 +335,7 @@ fn parse_args<'a>(
return Err(err);
}
if !regclass_outputs.is_empty() {
ecx.struct_span_err(
diag.struct_span_err(
regclass_outputs.clone(),
"asm with `clobber_abi` must specify explicit registers for outputs",
)
Expand Down

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