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Convert some macros from LegacyBang to Bang. #125094

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23 changes: 13 additions & 10 deletions compiler/rustc_builtin_macros/src/cfg.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -8,31 +8,34 @@ use rustc_ast::token;
use rustc_ast::tokenstream::TokenStream;
use rustc_attr as attr;
use rustc_errors::PResult;
use rustc_expand::base::{DummyResult, ExpandResult, ExtCtxt, MacEager, MacroExpanderResult};
use rustc_expand::base::ExtCtxt;
use rustc_span::symbol::kw;
use rustc_span::Span;

pub(crate) fn expand_cfg(
cx: &mut ExtCtxt<'_>,
sp: Span,
tts: TokenStream,
) -> MacroExpanderResult<'static> {
pub(crate) fn expand_cfg(cx: &mut ExtCtxt<'_>, sp: Span, tts: TokenStream) -> TokenStream {
let sp = cx.with_def_site_ctxt(sp);

ExpandResult::Ready(match parse_cfg(cx, sp, tts) {
let kind = match parse_cfg(cx, sp, tts) {
Ok(cfg) => {
let matches_cfg = attr::cfg_matches(
&cfg,
&cx.sess,
cx.current_expansion.lint_node_id,
Some(cx.ecfg.features),
);
MacEager::expr(cx.expr_bool(sp, matches_cfg))
let sym = if matches_cfg { kw::True } else { kw::False };
token::TokenKind::Ident(sym, token::IdentIsRaw::No)
}
Err(err) => {
let guar = err.emit();
DummyResult::any(sp, guar)
token::TokenKind::lit(
token::LitKind::Err(guar), // njn: ?
kw::Empty,
None,
)
}
})
};
TokenStream::token_alone(kind, sp)
}

fn parse_cfg<'a>(cx: &ExtCtxt<'a>, span: Span, tts: TokenStream) -> PResult<'a, ast::MetaItem> {
Expand Down
26 changes: 17 additions & 9 deletions compiler/rustc_builtin_macros/src/lib.rs
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Expand Up @@ -59,38 +59,46 @@ rustc_fluent_macro::fluent_messages! { "../messages.ftl" }
pub fn register_builtin_macros(resolver: &mut dyn ResolverExpand) {
let mut register = |name, kind| resolver.register_builtin_macro(name, kind);
macro register_bang($($name:ident: $f:expr,)*) {
$(register(sym::$name, SyntaxExtensionKind::Bang(Box::new($f)));)*
}
macro register_legacy_bang($($name:ident: $f:expr,)*) {
$(register(sym::$name, SyntaxExtensionKind::LegacyBang(Box::new($f as MacroExpanderFn)));)*
}
macro register_attr($($name:ident: $f:expr,)*) {
macro register_legacy_attr($($name:ident: $f:expr,)*) {
$(register(sym::$name, SyntaxExtensionKind::LegacyAttr(Box::new($f)));)*
}
macro register_derive($($name:ident: $f:expr,)*) {
macro register_legacy_derive($($name:ident: $f:expr,)*) {
$(register(sym::$name, SyntaxExtensionKind::LegacyDerive(Box::new(BuiltinDerive($f))));)*
}

register_bang! {
// tidy-alphabetical-start
asm: asm::expand_asm,
assert: assert::expand_assert,
cfg: cfg::expand_cfg,
column: source_util::expand_column,
file: source_util::expand_file,
line: source_util::expand_line,
module_path: source_util::expand_module_path,
// tidy-alphabetical-end
}

register_legacy_bang! {
// tidy-alphabetical-start
asm: asm::expand_asm,
assert: assert::expand_assert,
compile_error: compile_error::expand_compile_error,
concat: concat::expand_concat,
concat_bytes: concat_bytes::expand_concat_bytes,
concat_idents: concat_idents::expand_concat_idents,
const_format_args: format::expand_format_args,
core_panic: edition_panic::expand_panic,
env: env::expand_env,
file: source_util::expand_file,
format_args: format::expand_format_args,
format_args_nl: format::expand_format_args_nl,
global_asm: asm::expand_global_asm,
include: source_util::expand_include,
include_bytes: source_util::expand_include_bytes,
include_str: source_util::expand_include_str,
line: source_util::expand_line,
log_syntax: log_syntax::expand_log_syntax,
module_path: source_util::expand_mod,
option_env: env::expand_option_env,
pattern_type: pattern_type::expand,
std_panic: edition_panic::expand_panic,
Expand All @@ -100,7 +108,7 @@ pub fn register_builtin_macros(resolver: &mut dyn ResolverExpand) {
// tidy-alphabetical-end
}

register_attr! {
register_legacy_attr! {
alloc_error_handler: alloc_error_handler::expand,
bench: test::expand_bench,
cfg_accessible: cfg_accessible::Expander,
Expand All @@ -112,7 +120,7 @@ pub fn register_builtin_macros(resolver: &mut dyn ResolverExpand) {
test_case: test::expand_test_case,
}

register_derive! {
register_legacy_derive! {
Clone: clone::expand_deriving_clone,
Copy: bounds::expand_deriving_copy,
ConstParamTy: bounds::expand_deriving_const_param_ty,
Expand Down
55 changes: 26 additions & 29 deletions compiler/rustc_builtin_macros/src/source_util.rs
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Expand Up @@ -15,6 +15,7 @@ use rustc_parse::new_parser_from_file;
use rustc_parse::parser::{ForceCollect, Parser};
use rustc_session::lint::builtin::INCOMPLETE_INCLUDE;
use rustc_span::source_map::SourceMap;
use rustc_span::sym;
use rustc_span::symbol::Symbol;
use rustc_span::{Pos, Span};
use smallvec::SmallVec;
Expand All @@ -26,56 +27,54 @@ use std::rc::Rc;
// a given file into the current one.

/// line!(): expands to the current line number
pub(crate) fn expand_line(
cx: &mut ExtCtxt<'_>,
sp: Span,
tts: TokenStream,
) -> MacroExpanderResult<'static> {
pub(crate) fn expand_line(cx: &mut ExtCtxt<'_>, sp: Span, tts: TokenStream) -> TokenStream {
let sp = cx.with_def_site_ctxt(sp);
check_zero_tts(cx, sp, tts, "line!");

let topmost = cx.expansion_cause().unwrap_or(sp);
let loc = cx.source_map().lookup_char_pos(topmost.lo());

ExpandResult::Ready(MacEager::expr(cx.expr_u32(topmost, loc.line as u32)))
let kind = token::TokenKind::lit(
token::LitKind::Integer,
sym::integer(loc.line as u32),
Some(sym::u32),
);
TokenStream::token_alone(kind, topmost)
}

/* column!(): expands to the current column number */
pub(crate) fn expand_column(
cx: &mut ExtCtxt<'_>,
sp: Span,
tts: TokenStream,
) -> MacroExpanderResult<'static> {
pub(crate) fn expand_column(cx: &mut ExtCtxt<'_>, sp: Span, tts: TokenStream) -> TokenStream {
let sp = cx.with_def_site_ctxt(sp);
check_zero_tts(cx, sp, tts, "column!");

let topmost = cx.expansion_cause().unwrap_or(sp);
let loc = cx.source_map().lookup_char_pos(topmost.lo());

ExpandResult::Ready(MacEager::expr(cx.expr_u32(topmost, loc.col.to_usize() as u32 + 1)))
let kind = token::TokenKind::lit(
token::LitKind::Integer,
sym::integer(loc.col.to_usize() as u32 + 1),
Some(sym::u32),
);
TokenStream::token_alone(kind, topmost)
}

/// file!(): expands to the current filename */
/// The source_file (`loc.file`) contains a bunch more information we could spit
/// out if we wanted.
pub(crate) fn expand_file(
cx: &mut ExtCtxt<'_>,
sp: Span,
tts: TokenStream,
) -> MacroExpanderResult<'static> {
pub(crate) fn expand_file(cx: &mut ExtCtxt<'_>, sp: Span, tts: TokenStream) -> TokenStream {
let sp = cx.with_def_site_ctxt(sp);
check_zero_tts(cx, sp, tts, "file!");

let topmost = cx.expansion_cause().unwrap_or(sp);
let loc = cx.source_map().lookup_char_pos(topmost.lo());

use rustc_session::{config::RemapPathScopeComponents, RemapFileNameExt};
ExpandResult::Ready(MacEager::expr(cx.expr_str(
topmost,
Symbol::intern(
&loc.file.name.for_scope(cx.sess, RemapPathScopeComponents::MACRO).to_string_lossy(),
),
)))

let symbol = Symbol::intern(
&loc.file.name.for_scope(cx.sess, RemapPathScopeComponents::MACRO).to_string_lossy(),
);
let kind = token::TokenKind::lit(token::LitKind::Str, symbol, None);
TokenStream::token_alone(kind, topmost)
}

pub(crate) fn expand_stringify(
Expand All @@ -88,17 +87,15 @@ pub(crate) fn expand_stringify(
ExpandResult::Ready(MacEager::expr(cx.expr_str(sp, Symbol::intern(&s))))
}

pub(crate) fn expand_mod(
cx: &mut ExtCtxt<'_>,
sp: Span,
tts: TokenStream,
) -> MacroExpanderResult<'static> {
pub(crate) fn expand_module_path(cx: &mut ExtCtxt<'_>, sp: Span, tts: TokenStream) -> TokenStream {
let sp = cx.with_def_site_ctxt(sp);
check_zero_tts(cx, sp, tts, "module_path!");
let mod_path = &cx.current_expansion.module.mod_path;
let string = mod_path.iter().map(|x| x.to_string()).collect::<Vec<String>>().join("::");

ExpandResult::Ready(MacEager::expr(cx.expr_str(sp, Symbol::intern(&string))))
let symbol = Symbol::intern(&string);
let kind = token::TokenKind::lit(token::LitKind::Str, symbol, None);
TokenStream::token_alone(kind, sp)
}

/// include! : parse the given file as an expr
Expand Down
9 changes: 4 additions & 5 deletions compiler/rustc_expand/src/base.rs
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Expand Up @@ -290,16 +290,15 @@ pub trait BangProcMacro {

impl<F> BangProcMacro for F
where
F: Fn(TokenStream) -> TokenStream,
F: Fn(&mut ExtCtxt<'_>, Span, TokenStream) -> TokenStream,
{
fn expand<'cx>(
&self,
_ecx: &'cx mut ExtCtxt<'_>,
_span: Span,
ecx: &'cx mut ExtCtxt<'_>,
span: Span,
ts: TokenStream,
) -> Result<TokenStream, ErrorGuaranteed> {
// FIXME setup implicit context in TLS before calling self.
Ok(self(ts))
Ok(self(ecx, span, ts))
Comment on lines -293 to +301
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@SparrowLii SparrowLii May 14, 2024 •
edited
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I think we can improve the return types here to handle ExpandResult::Retry(()) . e.g.

pub enum BangRetry {
    Yes,
    No,
}

impl<F> BangProcMacro for F
where
    F: Fn(&mut ExtCtxt<'_>, Span, TokenStream) -> Result<TokenStream, BangRetry>,
{
    fn expand<'cx>(
        &self,
        ecx: &'cx mut ExtCtxt<'_>,
        span: Span,
        ts: TokenStream,
    ) -> Result<TokenStream, (BangRetry, ErrorGuaranteed)> {
        self(ecx, span, ts).map_err(|retry| (retry, ErrorGuaranteed(())))
    }
}

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@nnethercote nnethercote May 22, 2024

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It's a good suggestion. But I'll wait for feedback from @petrochenkov about whether converting LegacyBang to Bang is a good idea in general before putting more effort in.

@petrochenkov, what do you think?

}
}

Expand Down
2 changes: 1 addition & 1 deletion tests/ui/macros/macro-error.rs
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Expand Up @@ -5,5 +5,5 @@ macro_rules! foo {
fn main() {
foo!(0); // Check that we report errors at macro definition, not expansion.

let _: cfg!(FALSE) = (); //~ ERROR non-type macro in type position
let _: cfg!(FALSE) = (); //~ ERROR expected type, found keyword `false`
}
7 changes: 6 additions & 1 deletion tests/ui/macros/macro-error.stderr
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Expand Up @@ -4,11 +4,16 @@ error: macro rhs must be delimited
LL | ($a:expr) => a;
| ^

error: non-type macro in type position: cfg
error: expected type, found keyword `false`
--> $DIR/macro-error.rs:8:12
|
LL | let _: cfg!(FALSE) = ();
| ^^^^^^^^^^^
| |
| expected type
| this macro call doesn't expand to a type
|
= note: this error originates in the macro `cfg` (in Nightly builds, run with -Z macro-backtrace for more info)

error: aborting due to 2 previous errors