diff --git a/compiler/rustc_expand/src/proc_macro.rs b/compiler/rustc_expand/src/proc_macro.rs index 3f84979ac05e7..42c17a60a5d4e 100644 --- a/compiler/rustc_expand/src/proc_macro.rs +++ b/compiler/rustc_expand/src/proc_macro.rs @@ -24,8 +24,9 @@ impl base::ProcMacro for BangProcMacro { span: Span, input: TokenStream, ) -> Result { + let proc_macro_backtrace = ecx.ecfg.proc_macro_backtrace; let server = proc_macro_server::Rustc::new(ecx); - self.client.run(&EXEC_STRATEGY, server, input, ecx.ecfg.proc_macro_backtrace).map_err(|e| { + self.client.run(&EXEC_STRATEGY, server, input, proc_macro_backtrace).map_err(|e| { let mut err = ecx.struct_span_err(span, "proc macro panicked"); if let Some(s) = e.as_str() { err.help(&format!("message: {}", s)); @@ -48,9 +49,10 @@ impl base::AttrProcMacro for AttrProcMacro { annotation: TokenStream, annotated: TokenStream, ) -> Result { + let proc_macro_backtrace = ecx.ecfg.proc_macro_backtrace; let server = proc_macro_server::Rustc::new(ecx); self.client - .run(&EXEC_STRATEGY, server, annotation, annotated, ecx.ecfg.proc_macro_backtrace) + .run(&EXEC_STRATEGY, server, annotation, annotated, proc_macro_backtrace) .map_err(|e| { let mut err = ecx.struct_span_err(span, "custom attribute panicked"); if let Some(s) = e.as_str() { @@ -97,19 +99,19 @@ impl MultiItemModifier for ProcMacroDerive { nt_to_tokenstream(&item, &ecx.sess.parse_sess, CanSynthesizeMissingTokens::No) }; + let proc_macro_backtrace = ecx.ecfg.proc_macro_backtrace; let server = proc_macro_server::Rustc::new(ecx); - let stream = - match self.client.run(&EXEC_STRATEGY, server, input, ecx.ecfg.proc_macro_backtrace) { - Ok(stream) => stream, - Err(e) => { - let mut err = ecx.struct_span_err(span, "proc-macro derive panicked"); - if let Some(s) = e.as_str() { - err.help(&format!("message: {}", s)); - } - err.emit(); - return ExpandResult::Ready(vec![]); + let stream = match self.client.run(&EXEC_STRATEGY, server, input, proc_macro_backtrace) { + Ok(stream) => stream, + Err(e) => { + let mut err = ecx.struct_span_err(span, "proc-macro derive panicked"); + if let Some(s) = e.as_str() { + err.help(&format!("message: {}", s)); } - }; + err.emit(); + return ExpandResult::Ready(vec![]); + } + }; let error_count_before = ecx.sess.parse_sess.span_diagnostic.err_count(); let mut parser = diff --git a/compiler/rustc_expand/src/proc_macro_server.rs b/compiler/rustc_expand/src/proc_macro_server.rs index 66f6c00825900..fa9e98be9e881 100644 --- a/compiler/rustc_expand/src/proc_macro_server.rs +++ b/compiler/rustc_expand/src/proc_macro_server.rs @@ -1,4 +1,4 @@ -use crate::base::{ExtCtxt, ResolverExpand}; +use crate::base::ExtCtxt; use rustc_ast as ast; use rustc_ast::token::{self, Nonterminal, NtIdent}; @@ -7,7 +7,7 @@ use rustc_ast::tokenstream::{DelimSpan, Spacing::*, TokenStream, TreeAndSpacing} use rustc_ast_pretty::pprust; use rustc_data_structures::fx::FxHashMap; use rustc_data_structures::sync::Lrc; -use rustc_errors::Diagnostic; +use rustc_errors::{Diagnostic, PResult}; use rustc_lint_defs::builtin::PROC_MACRO_BACK_COMPAT; use rustc_lint_defs::BuiltinLintDiagnostics; use rustc_parse::lexer::nfc_normalize; @@ -53,11 +53,11 @@ impl ToInternal for Delimiter { } } -impl FromInternal<(TreeAndSpacing, &'_ mut Vec, &mut Rustc<'_>)> +impl FromInternal<(TreeAndSpacing, &'_ mut Vec, &mut Rustc<'_, '_>)> for TokenTree { fn from_internal( - ((tree, spacing), stack, rustc): (TreeAndSpacing, &mut Vec, &mut Rustc<'_>), + ((tree, spacing), stack, rustc): (TreeAndSpacing, &mut Vec, &mut Rustc<'_, '_>), ) -> Self { use rustc_ast::token::*; @@ -146,10 +146,10 @@ impl FromInternal<(TreeAndSpacing, &'_ mut Vec, &mut Rustc<'_>)> SingleQuote => op!('\''), Ident(name, false) if name == kw::DollarCrate => tt!(Ident::dollar_crate()), - Ident(name, is_raw) => tt!(Ident::new(rustc.sess, name, is_raw)), + Ident(name, is_raw) => tt!(Ident::new(rustc.sess(), name, is_raw)), Lifetime(name) => { let ident = symbol::Ident::new(name, span).without_first_quote(); - stack.push(tt!(Ident::new(rustc.sess, ident.name, false))); + stack.push(tt!(Ident::new(rustc.sess(), ident.name, false))); tt!(Punct::new('\'', true)) } Literal(lit) => tt!(Literal { lit }), @@ -181,15 +181,15 @@ impl FromInternal<(TreeAndSpacing, &'_ mut Vec, &mut Rustc<'_>)> Interpolated(nt) if let Some((name, is_raw)) = ident_name_compatibility_hack(&nt, span, rustc) => { - TokenTree::Ident(Ident::new(rustc.sess, name.name, is_raw, name.span)) + TokenTree::Ident(Ident::new(rustc.sess(), name.name, is_raw, name.span)) } Interpolated(nt) => { - let stream = nt_to_tokenstream(&nt, rustc.sess, CanSynthesizeMissingTokens::No); + let stream = nt_to_tokenstream(&nt, rustc.sess(), CanSynthesizeMissingTokens::No); TokenTree::Group(Group { delimiter: Delimiter::None, stream, span: DelimSpan::from_single(span), - flatten: crate::base::pretty_printing_compatibility_hack(&nt, rustc.sess), + flatten: crate::base::pretty_printing_compatibility_hack(&nt, rustc.sess()), }) } @@ -355,38 +355,38 @@ pub struct Literal { span: Span, } -pub(crate) struct Rustc<'a> { - resolver: &'a dyn ResolverExpand, - sess: &'a ParseSess, +pub(crate) struct Rustc<'a, 'b> { + ecx: &'a mut ExtCtxt<'b>, def_site: Span, call_site: Span, mixed_site: Span, - span_debug: bool, krate: CrateNum, rebased_spans: FxHashMap, } -impl<'a> Rustc<'a> { - pub fn new(cx: &'a ExtCtxt<'_>) -> Self { - let expn_data = cx.current_expansion.id.expn_data(); +impl<'a, 'b> Rustc<'a, 'b> { + pub fn new(ecx: &'a mut ExtCtxt<'b>) -> Self { + let expn_data = ecx.current_expansion.id.expn_data(); Rustc { - resolver: cx.resolver, - sess: cx.parse_sess(), - def_site: cx.with_def_site_ctxt(expn_data.def_site), - call_site: cx.with_call_site_ctxt(expn_data.call_site), - mixed_site: cx.with_mixed_site_ctxt(expn_data.call_site), - span_debug: cx.ecfg.span_debug, + def_site: ecx.with_def_site_ctxt(expn_data.def_site), + call_site: ecx.with_call_site_ctxt(expn_data.call_site), + mixed_site: ecx.with_mixed_site_ctxt(expn_data.call_site), krate: expn_data.macro_def_id.unwrap().krate, rebased_spans: FxHashMap::default(), + ecx, } } + fn sess(&self) -> &ParseSess { + self.ecx.parse_sess() + } + fn lit(&mut self, kind: token::LitKind, symbol: Symbol, suffix: Option) -> Literal { Literal { lit: token::Lit::new(kind, symbol, suffix), span: server::Span::call_site(self) } } } -impl server::Types for Rustc<'_> { +impl server::Types for Rustc<'_, '_> { type FreeFunctions = FreeFunctions; type TokenStream = TokenStream; type TokenStreamBuilder = tokenstream::TokenStreamBuilder; @@ -401,17 +401,20 @@ impl server::Types for Rustc<'_> { type Span = Span; } -impl server::FreeFunctions for Rustc<'_> { +impl server::FreeFunctions for Rustc<'_, '_> { fn track_env_var(&mut self, var: &str, value: Option<&str>) { - self.sess.env_depinfo.borrow_mut().insert((Symbol::intern(var), value.map(Symbol::intern))); + self.sess() + .env_depinfo + .borrow_mut() + .insert((Symbol::intern(var), value.map(Symbol::intern))); } fn track_path(&mut self, path: &str) { - self.sess.file_depinfo.borrow_mut().insert(Symbol::intern(path)); + self.sess().file_depinfo.borrow_mut().insert(Symbol::intern(path)); } } -impl server::TokenStream for Rustc<'_> { +impl server::TokenStream for Rustc<'_, '_> { fn new(&mut self) -> Self::TokenStream { TokenStream::default() } @@ -422,13 +425,62 @@ impl server::TokenStream for Rustc<'_> { parse_stream_from_source_str( FileName::proc_macro_source_code(src), src.to_string(), - self.sess, + self.sess(), Some(self.call_site), ) } fn to_string(&mut self, stream: &Self::TokenStream) -> String { pprust::tts_to_string(stream) } + fn expand_expr(&mut self, stream: &Self::TokenStream) -> Result { + // Parse the expression from our tokenstream. + let expr: PResult<'_, _> = try { + let mut p = rustc_parse::stream_to_parser( + self.sess(), + stream.clone(), + Some("proc_macro expand expr"), + ); + let expr = p.parse_expr()?; + if p.token != token::Eof { + p.unexpected()?; + } + expr + }; + let expr = expr.map_err(|mut err| err.emit())?; + + // Perform eager expansion on the expression. + let expr = self + .ecx + .expander() + .fully_expand_fragment(crate::expand::AstFragment::Expr(expr)) + .make_expr(); + + // NOTE: For now, limit `expand_expr` to exclusively expand to literals. + // This may be relaxed in the future. + // We don't use `nt_to_tokenstream` as the tokenstream currently cannot + // be recovered in the general case. + match &expr.kind { + ast::ExprKind::Lit(l) => { + Ok(tokenstream::TokenTree::token(token::Literal(l.token), l.span).into()) + } + ast::ExprKind::Unary(ast::UnOp::Neg, e) => match &e.kind { + ast::ExprKind::Lit(l) => match l.token { + token::Lit { kind: token::Integer | token::Float, .. } => { + Ok(std::array::IntoIter::new([ + // FIXME: The span of the `-` token is lost when + // parsing, so we cannot faithfully recover it here. + tokenstream::TokenTree::token(token::BinOp(token::Minus), e.span), + tokenstream::TokenTree::token(token::Literal(l.token), l.span), + ]) + .collect()) + } + _ => Err(()), + }, + _ => Err(()), + }, + _ => Err(()), + } + } fn from_token_tree( &mut self, tree: TokenTree, @@ -440,7 +492,7 @@ impl server::TokenStream for Rustc<'_> { } } -impl server::TokenStreamBuilder for Rustc<'_> { +impl server::TokenStreamBuilder for Rustc<'_, '_> { fn new(&mut self) -> Self::TokenStreamBuilder { tokenstream::TokenStreamBuilder::new() } @@ -452,7 +504,7 @@ impl server::TokenStreamBuilder for Rustc<'_> { } } -impl server::TokenStreamIter for Rustc<'_> { +impl server::TokenStreamIter for Rustc<'_, '_> { fn next( &mut self, iter: &mut Self::TokenStreamIter, @@ -477,7 +529,7 @@ impl server::TokenStreamIter for Rustc<'_> { } } -impl server::Group for Rustc<'_> { +impl server::Group for Rustc<'_, '_> { fn new(&mut self, delimiter: Delimiter, stream: Self::TokenStream) -> Self::Group { Group { delimiter, @@ -506,7 +558,7 @@ impl server::Group for Rustc<'_> { } } -impl server::Punct for Rustc<'_> { +impl server::Punct for Rustc<'_, '_> { fn new(&mut self, ch: char, spacing: Spacing) -> Self::Punct { Punct::new(ch, spacing == Spacing::Joint, server::Span::call_site(self)) } @@ -524,9 +576,9 @@ impl server::Punct for Rustc<'_> { } } -impl server::Ident for Rustc<'_> { +impl server::Ident for Rustc<'_, '_> { fn new(&mut self, string: &str, span: Self::Span, is_raw: bool) -> Self::Ident { - Ident::new(self.sess, Symbol::intern(string), is_raw, span) + Ident::new(self.sess(), Symbol::intern(string), is_raw, span) } fn span(&mut self, ident: Self::Ident) -> Self::Span { ident.span @@ -536,10 +588,10 @@ impl server::Ident for Rustc<'_> { } } -impl server::Literal for Rustc<'_> { +impl server::Literal for Rustc<'_, '_> { fn from_str(&mut self, s: &str) -> Result { let name = FileName::proc_macro_source_code(s); - let mut parser = rustc_parse::new_parser_from_source_str(self.sess, name, s.to_owned()); + let mut parser = rustc_parse::new_parser_from_source_str(self.sess(), name, s.to_owned()); let first_span = parser.token.span.data(); let minus_present = parser.eat(&token::BinOp(token::Minus)); @@ -675,7 +727,7 @@ impl server::Literal for Rustc<'_> { } } -impl server::SourceFile for Rustc<'_> { +impl server::SourceFile for Rustc<'_, '_> { fn eq(&mut self, file1: &Self::SourceFile, file2: &Self::SourceFile) -> bool { Lrc::ptr_eq(file1, file2) } @@ -695,7 +747,7 @@ impl server::SourceFile for Rustc<'_> { } } -impl server::MultiSpan for Rustc<'_> { +impl server::MultiSpan for Rustc<'_, '_> { fn new(&mut self) -> Self::MultiSpan { vec![] } @@ -704,7 +756,7 @@ impl server::MultiSpan for Rustc<'_> { } } -impl server::Diagnostic for Rustc<'_> { +impl server::Diagnostic for Rustc<'_, '_> { fn new(&mut self, level: Level, msg: &str, spans: Self::MultiSpan) -> Self::Diagnostic { let mut diag = Diagnostic::new(level.to_internal(), msg); diag.set_span(MultiSpan::from_spans(spans)); @@ -720,13 +772,13 @@ impl server::Diagnostic for Rustc<'_> { diag.sub(level.to_internal(), msg, MultiSpan::from_spans(spans), None); } fn emit(&mut self, diag: Self::Diagnostic) { - self.sess.span_diagnostic.emit_diagnostic(&diag); + self.sess().span_diagnostic.emit_diagnostic(&diag); } } -impl server::Span for Rustc<'_> { +impl server::Span for Rustc<'_, '_> { fn debug(&mut self, span: Self::Span) -> String { - if self.span_debug { + if self.ecx.ecfg.span_debug { format!("{:?}", span) } else { format!("{:?} bytes({}..{})", span.ctxt(), span.lo().0, span.hi().0) @@ -742,7 +794,7 @@ impl server::Span for Rustc<'_> { self.mixed_site } fn source_file(&mut self, span: Self::Span) -> Self::SourceFile { - self.sess.source_map().lookup_char_pos(span.lo()).file + self.sess().source_map().lookup_char_pos(span.lo()).file } fn parent(&mut self, span: Self::Span) -> Option { span.parent_callsite() @@ -751,11 +803,11 @@ impl server::Span for Rustc<'_> { span.source_callsite() } fn start(&mut self, span: Self::Span) -> LineColumn { - let loc = self.sess.source_map().lookup_char_pos(span.lo()); + let loc = self.sess().source_map().lookup_char_pos(span.lo()); LineColumn { line: loc.line, column: loc.col.to_usize() } } fn end(&mut self, span: Self::Span) -> LineColumn { - let loc = self.sess.source_map().lookup_char_pos(span.hi()); + let loc = self.sess().source_map().lookup_char_pos(span.hi()); LineColumn { line: loc.line, column: loc.col.to_usize() } } fn before(&mut self, span: Self::Span) -> Self::Span { @@ -765,8 +817,8 @@ impl server::Span for Rustc<'_> { span.shrink_to_hi() } fn join(&mut self, first: Self::Span, second: Self::Span) -> Option { - let self_loc = self.sess.source_map().lookup_char_pos(first.lo()); - let other_loc = self.sess.source_map().lookup_char_pos(second.lo()); + let self_loc = self.sess().source_map().lookup_char_pos(first.lo()); + let other_loc = self.sess().source_map().lookup_char_pos(second.lo()); if self_loc.file.name != other_loc.file.name { return None; @@ -778,7 +830,7 @@ impl server::Span for Rustc<'_> { span.with_ctxt(at.ctxt()) } fn source_text(&mut self, span: Self::Span) -> Option { - self.sess.source_map().span_to_snippet(span).ok() + self.sess().source_map().span_to_snippet(span).ok() } /// Saves the provided span into the metadata of /// *the crate we are currently compiling*, which must @@ -805,10 +857,10 @@ impl server::Span for Rustc<'_> { /// since we've loaded `my_proc_macro` from disk in order to execute it). /// In this way, we have obtained a span pointing into `my_proc_macro` fn save_span(&mut self, span: Self::Span) -> usize { - self.sess.save_proc_macro_span(span) + self.sess().save_proc_macro_span(span) } fn recover_proc_macro_span(&mut self, id: usize) -> Self::Span { - let (resolver, krate, def_site) = (self.resolver, self.krate, self.def_site); + let (resolver, krate, def_site) = (&*self.ecx.resolver, self.krate, self.def_site); *self.rebased_spans.entry(id).or_insert_with(|| { // FIXME: `SyntaxContext` for spans from proc macro crates is lost during encoding, // replace it with a def-site context until we are encoding it properly. @@ -821,11 +873,11 @@ impl server::Span for Rustc<'_> { fn ident_name_compatibility_hack( nt: &Nonterminal, orig_span: Span, - rustc: &mut Rustc<'_>, + rustc: &mut Rustc<'_, '_>, ) -> Option<(rustc_span::symbol::Ident, bool)> { if let NtIdent(ident, is_raw) = nt { if let ExpnKind::Macro(_, macro_name) = orig_span.ctxt().outer_expn_data().kind { - let source_map = rustc.sess.source_map(); + let source_map = rustc.sess().source_map(); let filename = source_map.span_to_filename(orig_span); if let FileName::Real(RealFileName::LocalPath(path)) = filename { let matches_prefix = |prefix, filename| { @@ -846,7 +898,7 @@ fn ident_name_compatibility_hack( let snippet = source_map.span_to_snippet(orig_span); if snippet.as_deref() == Ok("$name") { if time_macros_impl { - rustc.sess.buffer_lint_with_diagnostic( + rustc.sess().buffer_lint_with_diagnostic( &PROC_MACRO_BACK_COMPAT, orig_span, ast::CRATE_NODE_ID, @@ -871,7 +923,7 @@ fn ident_name_compatibility_hack( .and_then(|c| c.parse::().ok()) .map_or(false, |v| v < 40) { - rustc.sess.buffer_lint_with_diagnostic( + rustc.sess().buffer_lint_with_diagnostic( &PROC_MACRO_BACK_COMPAT, orig_span, ast::CRATE_NODE_ID, @@ -894,7 +946,7 @@ fn ident_name_compatibility_hack( source_map.span_to_filename(rustc.def_site) { if macro_path.to_string_lossy().contains("pin-project-internal-0.") { - rustc.sess.buffer_lint_with_diagnostic( + rustc.sess().buffer_lint_with_diagnostic( &PROC_MACRO_BACK_COMPAT, orig_span, ast::CRATE_NODE_ID, diff --git a/library/proc_macro/src/bridge/mod.rs b/library/proc_macro/src/bridge/mod.rs index bb05506defd07..2df287f7d9300 100644 --- a/library/proc_macro/src/bridge/mod.rs +++ b/library/proc_macro/src/bridge/mod.rs @@ -62,6 +62,7 @@ macro_rules! with_api { fn clone($self: &$S::TokenStream) -> $S::TokenStream; fn new() -> $S::TokenStream; fn is_empty($self: &$S::TokenStream) -> bool; + fn expand_expr($self: &$S::TokenStream) -> Result<$S::TokenStream, ()>; fn from_str(src: &str) -> $S::TokenStream; fn to_string($self: &$S::TokenStream) -> String; fn from_token_tree( diff --git a/library/proc_macro/src/lib.rs b/library/proc_macro/src/lib.rs index 9d673d6968719..ef96d72a38b54 100644 --- a/library/proc_macro/src/lib.rs +++ b/library/proc_macro/src/lib.rs @@ -88,12 +88,6 @@ impl !Sync for TokenStream {} #[derive(Debug)] pub struct LexError; -impl LexError { - fn new() -> Self { - LexError - } -} - #[stable(feature = "proc_macro_lexerror_impls", since = "1.44.0")] impl fmt::Display for LexError { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { @@ -109,6 +103,28 @@ impl !Send for LexError {} #[stable(feature = "proc_macro_lib", since = "1.15.0")] impl !Sync for LexError {} +/// Error returned from `TokenStream::expand_expr`. +#[unstable(feature = "proc_macro_expand", issue = "90765")] +#[non_exhaustive] +#[derive(Debug)] +pub struct ExpandError; + +#[unstable(feature = "proc_macro_expand", issue = "90765")] +impl fmt::Display for ExpandError { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.write_str("macro expansion failed") + } +} + +#[unstable(feature = "proc_macro_expand", issue = "90765")] +impl error::Error for ExpandError {} + +#[unstable(feature = "proc_macro_expand", issue = "90765")] +impl !Send for ExpandError {} + +#[unstable(feature = "proc_macro_expand", issue = "90765")] +impl !Sync for ExpandError {} + impl TokenStream { /// Returns an empty `TokenStream` containing no token trees. #[stable(feature = "proc_macro_lib2", since = "1.29.0")] @@ -121,6 +137,24 @@ impl TokenStream { pub fn is_empty(&self) -> bool { self.0.is_empty() } + + /// Parses this `TokenStream` as an expression and attempts to expand any + /// macros within it. Returns the expanded `TokenStream`. + /// + /// Currently only expressions expanding to literals will succeed, although + /// this may be relaxed in the future. + /// + /// NOTE: In error conditions, `expand_expr` may leave macros unexpanded, + /// report an error, failing compilation, and/or return an `Err(..)`. The + /// specific behavior for any error condition, and what conditions are + /// considered errors, is unspecified and may change in the future. + #[unstable(feature = "proc_macro_expand", issue = "90765")] + pub fn expand_expr(&self) -> Result { + match bridge::client::TokenStream::expand_expr(&self.0) { + Ok(stream) => Ok(TokenStream(stream)), + Err(_) => Err(ExpandError), + } + } } /// Attempts to break the string into tokens and parse those tokens into a token stream. @@ -1211,7 +1245,7 @@ impl FromStr for Literal { fn from_str(src: &str) -> Result { match bridge::client::Literal::from_str(src) { Ok(literal) => Ok(Literal(literal)), - Err(()) => Err(LexError::new()), + Err(()) => Err(LexError), } } } diff --git a/src/test/ui/proc-macro/auxiliary/expand-expr.rs b/src/test/ui/proc-macro/auxiliary/expand-expr.rs new file mode 100644 index 0000000000000..2bc34f3c6bfc0 --- /dev/null +++ b/src/test/ui/proc-macro/auxiliary/expand-expr.rs @@ -0,0 +1,80 @@ +// force-host +// no-prefer-dynamic + +#![crate_type = "proc-macro"] +#![deny(warnings)] +#![feature(proc_macro_expand, proc_macro_span)] + +extern crate proc_macro; + +use proc_macro::*; +use std::str::FromStr; + +#[proc_macro] +pub fn expand_expr_is(input: TokenStream) -> TokenStream { + let mut iter = input.into_iter(); + let mut expected_tts = Vec::new(); + loop { + match iter.next() { + Some(TokenTree::Punct(ref p)) if p.as_char() == ',' => break, + Some(tt) => expected_tts.push(tt), + None => panic!("expected comma"), + } + } + + let expected = expected_tts.into_iter().collect::(); + let expanded = iter.collect::().expand_expr().expect("expand_expr failed"); + assert!( + expected.to_string() == expanded.to_string(), + "assert failed\nexpected: `{}`\nexpanded: `{}`", + expected.to_string(), + expanded.to_string() + ); + + TokenStream::new() +} + +#[proc_macro] +pub fn expand_expr_fail(input: TokenStream) -> TokenStream { + match input.expand_expr() { + Ok(ts) => panic!("expand_expr unexpectedly succeeded: `{}`", ts), + Err(_) => TokenStream::new(), + } +} + +#[proc_macro] +pub fn check_expand_expr_file(ts: TokenStream) -> TokenStream { + // Check that the passed in `file!()` invocation and a parsed `file!` + // invocation expand to the same literal. + let input_t = ts.expand_expr().expect("expand_expr failed on macro input").to_string(); + let parse_t = TokenStream::from_str("file!{}") + .unwrap() + .expand_expr() + .expect("expand_expr failed on internal macro") + .to_string(); + assert_eq!(input_t, parse_t); + + // Check that the literal matches `Span::call_site().source_file().path()` + let expect_t = + Literal::string(&Span::call_site().source_file().path().to_string_lossy()).to_string(); + assert_eq!(input_t, expect_t); + + TokenStream::new() +} + +#[proc_macro] +pub fn recursive_expand(_: TokenStream) -> TokenStream { + // Recursively call until we hit the recursion limit and get an error. + // + // NOTE: This doesn't panic if expansion fails because that'll cause a very + // large number of errors to fill the output. + TokenStream::from_str("recursive_expand!{}") + .unwrap() + .expand_expr() + .unwrap_or(std::iter::once(TokenTree::Literal(Literal::u32_suffixed(0))).collect()) +} + +#[proc_macro] +pub fn echo_pm(input: TokenStream) -> TokenStream { + input +} diff --git a/src/test/ui/proc-macro/auxiliary/included-file.txt b/src/test/ui/proc-macro/auxiliary/included-file.txt new file mode 100644 index 0000000000000..b4720047d6cff --- /dev/null +++ b/src/test/ui/proc-macro/auxiliary/included-file.txt @@ -0,0 +1 @@ +Included file contents diff --git a/src/test/ui/proc-macro/expand-expr.rs b/src/test/ui/proc-macro/expand-expr.rs new file mode 100644 index 0000000000000..d1146d9703062 --- /dev/null +++ b/src/test/ui/proc-macro/expand-expr.rs @@ -0,0 +1,121 @@ +// aux-build:expand-expr.rs + +extern crate expand_expr; + +use expand_expr::{ + check_expand_expr_file, echo_pm, expand_expr_fail, expand_expr_is, recursive_expand, +}; + +// Check builtin macros can be expanded. + +expand_expr_is!(11u32, line!()); +expand_expr_is!(24u32, column!()); + +expand_expr_is!("Hello, World!", concat!("Hello, ", "World", "!")); +expand_expr_is!("int10floats5.3booltrue", concat!("int", 10, "floats", 5.3, "bool", true)); +expand_expr_is!("Hello", concat!(r##"Hello"##)); + +expand_expr_is!("Included file contents\n", include_str!("auxiliary/included-file.txt")); +expand_expr_is!(b"Included file contents\n", include_bytes!("auxiliary/included-file.txt")); + +expand_expr_is!( + "contents: Included file contents\n", + concat!("contents: ", include_str!("auxiliary/included-file.txt")) +); + +// Correct value is checked for multiple sources. +check_expand_expr_file!(file!()); + +expand_expr_is!("hello", stringify!(hello)); +expand_expr_is!("10 + 20", stringify!(10 + 20)); + +macro_rules! echo_tts { + ($($t:tt)*) => { $($t)* }; //~ ERROR: expected expression, found `$` +} + +macro_rules! echo_lit { + ($l:literal) => { + $l + }; +} + +macro_rules! echo_expr { + ($e:expr) => { + $e + }; +} + +macro_rules! simple_lit { + ($l:literal) => { + expand_expr_is!($l, $l); + expand_expr_is!($l, echo_lit!($l)); + expand_expr_is!($l, echo_expr!($l)); + expand_expr_is!($l, echo_tts!($l)); + expand_expr_is!($l, echo_pm!($l)); + const _: () = { + macro_rules! mac { + () => { + $l + }; + } + expand_expr_is!($l, mac!()); + expand_expr_is!($l, echo_expr!(mac!())); + expand_expr_is!($l, echo_tts!(mac!())); + expand_expr_is!($l, echo_pm!(mac!())); + }; + }; +} + +simple_lit!("Hello, World"); +simple_lit!('c'); +simple_lit!(b'c'); +simple_lit!(10); +simple_lit!(10.0); +simple_lit!(10.0f64); +simple_lit!(-3.14159); +simple_lit!(-3.5e10); +simple_lit!(0xFEED); +simple_lit!(-0xFEED); +simple_lit!(0b0100); +simple_lit!(-0b0100); +simple_lit!("string"); +simple_lit!(r##"raw string"##); +simple_lit!(b"byte string"); +simple_lit!(br##"raw byte string"##); +simple_lit!(true); +simple_lit!(false); + +// Ensure char escapes aren't normalized by expansion +simple_lit!("\u{0}"); +simple_lit!("\0"); +simple_lit!("\x00"); +simple_lit!('\u{0}'); +simple_lit!('\0'); +simple_lit!('\x00'); +simple_lit!(b"\x00"); +simple_lit!(b"\0"); +simple_lit!(b'\x00'); +simple_lit!(b'\0'); + +// Extra tokens after the string literal aren't ignored +expand_expr_fail!("string"; hello); //~ ERROR: expected one of `.`, `?`, or an operator, found `;` + +// Invalid expressions produce errors in addition to returning `Err(())`. +expand_expr_fail!($); //~ ERROR: expected expression, found `$` +expand_expr_fail!(echo_tts!($)); +expand_expr_fail!(echo_pm!($)); //~ ERROR: expected expression, found `$` + +// We get errors reported and recover during macro expansion if the macro +// doesn't produce a valid expression. +expand_expr_is!("string", echo_tts!("string"; hello)); //~ ERROR: macro expansion ignores token `hello` and any following +expand_expr_is!("string", echo_pm!("string"; hello)); //~ ERROR: macro expansion ignores token `;` and any following + +// For now, fail if a non-literal expression is expanded. +expand_expr_fail!(arbitrary_expression() + "etc"); +expand_expr_fail!(echo_tts!(arbitrary_expression() + "etc")); +expand_expr_fail!(echo_expr!(arbitrary_expression() + "etc")); +expand_expr_fail!(echo_pm!(arbitrary_expression() + "etc")); + +const _: u32 = recursive_expand!(); //~ ERROR: recursion limit reached while expanding `recursive_expand!` + +fn main() {} diff --git a/src/test/ui/proc-macro/expand-expr.stderr b/src/test/ui/proc-macro/expand-expr.stderr new file mode 100644 index 0000000000000..8dc2d0cfc2f85 --- /dev/null +++ b/src/test/ui/proc-macro/expand-expr.stderr @@ -0,0 +1,55 @@ +error: expected one of `.`, `?`, or an operator, found `;` + --> $DIR/expand-expr.rs:101:27 + | +LL | expand_expr_fail!("string"; hello); + | ^ expected one of `.`, `?`, or an operator + +error: expected expression, found `$` + --> $DIR/expand-expr.rs:104:19 + | +LL | expand_expr_fail!($); + | ^ expected expression + +error: expected expression, found `$` + --> $DIR/expand-expr.rs:33:23 + | +LL | ($($t:tt)*) => { $($t)* }; + | ^^^^ expected expression + +error: expected expression, found `$` + --> $DIR/expand-expr.rs:106:28 + | +LL | expand_expr_fail!(echo_pm!($)); + | ^ expected expression + +error: macro expansion ignores token `hello` and any following + --> $DIR/expand-expr.rs:110:47 + | +LL | expand_expr_is!("string", echo_tts!("string"; hello)); + | --------------------^^^^^-- help: you might be missing a semicolon here: `;` + | | + | caused by the macro expansion here + | + = note: the usage of `echo_tts!` is likely invalid in expression context + +error: macro expansion ignores token `;` and any following + --> $DIR/expand-expr.rs:111:44 + | +LL | expand_expr_is!("string", echo_pm!("string"; hello)); + | -----------------^-------- help: you might be missing a semicolon here: `;` + | | + | caused by the macro expansion here + | + = note: the usage of `echo_pm!` is likely invalid in expression context + +error: recursion limit reached while expanding `recursive_expand!` + --> $DIR/expand-expr.rs:119:16 + | +LL | const _: u32 = recursive_expand!(); + | ^^^^^^^^^^^^^^^^^^^ + | + = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`expand_expr`) + = note: this error originates in the macro `recursive_expand` (in Nightly builds, run with -Z macro-backtrace for more info) + +error: aborting due to 7 previous errors +