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Commit | Line | Data |
---|---|---|
74b04a01 | 1 | use rustc_ast::ptr::P; |
2b03887a | 2 | use rustc_ast::token; |
74b04a01 | 3 | use rustc_ast::tokenstream::TokenStream; |
2b03887a FG |
4 | use rustc_ast::Expr; |
5 | use rustc_data_structures::fx::FxHashSet; | |
04454e1e | 6 | use rustc_errors::{pluralize, Applicability, MultiSpan, PResult}; |
dfeec247 | 7 | use rustc_expand::base::{self, *}; |
f035d41b | 8 | use rustc_parse_format as parse; |
2b03887a | 9 | use rustc_span::symbol::{Ident, Symbol}; |
064997fb | 10 | use rustc_span::{BytePos, InnerSpan, Span}; |
1a4d82fc | 11 | |
064997fb FG |
12 | use rustc_lint_defs::builtin::NAMED_ARGUMENTS_USED_POSITIONALLY; |
13 | use rustc_lint_defs::{BufferedEarlyLint, BuiltinLintDiagnostics, LintId}; | |
064997fb | 14 | |
2b03887a FG |
15 | mod ast; |
16 | use ast::*; | |
1a4d82fc | 17 | |
2b03887a FG |
18 | mod expand; |
19 | use expand::expand_parsed_format_args; | |
1a4d82fc | 20 | |
2b03887a FG |
21 | // The format_args!() macro is expanded in three steps: |
22 | // 1. First, `parse_args` will parse the `(literal, arg, arg, name=arg, name=arg)` syntax, | |
23 | // but doesn't parse the template (the literal) itself. | |
24 | // 2. Second, `make_format_args` will parse the template, the format options, resolve argument references, | |
25 | // produce diagnostics, and turn the whole thing into a `FormatArgs` structure. | |
26 | // 3. Finally, `expand_parsed_format_args` will turn that `FormatArgs` structure | |
27 | // into the expression that the macro expands to. | |
5bcae85e | 28 | |
2b03887a | 29 | // See format/ast.rs for the FormatArgs structure and glossary. |
1a4d82fc | 30 | |
2b03887a FG |
31 | // Only used in parse_args and report_invalid_references, |
32 | // to indicate how a referred argument was used. | |
33 | #[derive(Clone, Copy, Debug, PartialEq, Eq)] | |
34 | enum PositionUsedAs { | |
35 | Placeholder(Option<Span>), | |
36 | Precision, | |
37 | Width, | |
1a4d82fc | 38 | } |
2b03887a | 39 | use PositionUsedAs::*; |
1a4d82fc | 40 | |
0731742a | 41 | /// Parses the arguments from the given list of tokens, returning the diagnostic |
1a4d82fc JJ |
42 | /// if there's a parse error so we can continue parsing other format! |
43 | /// expressions. | |
44 | /// | |
45 | /// If parsing succeeds, the return value is: | |
041b39d2 XL |
46 | /// |
47 | /// ```text | |
2b03887a | 48 | /// Ok((fmtstr, parsed arguments)) |
92a42be0 | 49 | /// ``` |
0731742a XL |
50 | fn parse_args<'a>( |
51 | ecx: &mut ExtCtxt<'a>, | |
52 | sp: Span, | |
e1599b0c | 53 | tts: TokenStream, |
2b03887a FG |
54 | ) -> PResult<'a, (P<Expr>, FormatArguments)> { |
55 | let mut args = FormatArguments::new(); | |
1a4d82fc JJ |
56 | |
57 | let mut p = ecx.new_parser_from_tts(tts); | |
58 | ||
59 | if p.token == token::Eof { | |
0731742a | 60 | return Err(ecx.struct_span_err(sp, "requires at least a format string argument")); |
1a4d82fc | 61 | } |
b7449926 | 62 | |
1b1a35ee XL |
63 | let first_token = &p.token; |
64 | let fmtstr = match first_token.kind { | |
65 | token::TokenKind::Literal(token::Lit { | |
66 | kind: token::LitKind::Str | token::LitKind::StrRaw(_), | |
67 | .. | |
68 | }) => { | |
69 | // If the first token is a string literal, then a format expression | |
70 | // is constructed from it. | |
71 | // | |
72 | // This allows us to properly handle cases when the first comma | |
73 | // after the format string is mistakenly replaced with any operator, | |
74 | // which cause the expression parser to eat too much tokens. | |
75 | p.parse_literal_maybe_minus()? | |
76 | } | |
77 | _ => { | |
78 | // Otherwise, we fall back to the expression parser. | |
79 | p.parse_expr()? | |
80 | } | |
81 | }; | |
82 | ||
e1599b0c | 83 | let mut first = true; |
b7449926 | 84 | |
1a4d82fc | 85 | while p.token != token::Eof { |
9cc50fc6 | 86 | if !p.eat(&token::Comma) { |
e1599b0c | 87 | if first { |
1b1a35ee XL |
88 | p.clear_expected_tokens(); |
89 | } | |
90 | ||
c295e0f8 XL |
91 | match p.expect(&token::Comma) { |
92 | Err(mut err) => { | |
93 | match token::TokenKind::Comma.similar_tokens() { | |
94 | Some(tks) if tks.contains(&p.token.kind) => { | |
95 | // If a similar token is found, then it may be a typo. We | |
96 | // consider it as a comma, and continue parsing. | |
97 | err.emit(); | |
98 | p.bump(); | |
99 | } | |
100 | // Otherwise stop the parsing and return the error. | |
101 | _ => return Err(err), | |
102 | } | |
103 | } | |
104 | Ok(recovered) => { | |
105 | assert!(recovered); | |
1b1a35ee | 106 | } |
e1599b0c | 107 | } |
1a4d82fc | 108 | } |
e1599b0c | 109 | first = false; |
9e0c209e SL |
110 | if p.token == token::Eof { |
111 | break; | |
112 | } // accept trailing commas | |
74b04a01 XL |
113 | match p.token.ident() { |
114 | Some((ident, _)) if p.look_ahead(1, |t| *t == token::Eq) => { | |
0731742a | 115 | p.bump(); |
74b04a01 | 116 | p.expect(&token::Eq)?; |
2b03887a FG |
117 | let expr = p.parse_expr()?; |
118 | if let Some((_, prev)) = args.by_name(ident.name) { | |
119 | ecx.struct_span_err( | |
120 | ident.span, | |
121 | &format!("duplicate argument named `{}`", ident), | |
122 | ) | |
123 | .span_label(prev.kind.ident().unwrap().span, "previously here") | |
124 | .span_label(ident.span, "duplicate argument") | |
125 | .emit(); | |
74b04a01 XL |
126 | continue; |
127 | } | |
2b03887a | 128 | args.add(FormatArgument { kind: FormatArgumentKind::Named(ident), expr }); |
1a4d82fc | 129 | } |
74b04a01 | 130 | _ => { |
2b03887a FG |
131 | let expr = p.parse_expr()?; |
132 | if !args.named_args().is_empty() { | |
74b04a01 | 133 | let mut err = ecx.struct_span_err( |
2b03887a | 134 | expr.span, |
74b04a01 XL |
135 | "positional arguments cannot follow named arguments", |
136 | ); | |
2b03887a FG |
137 | err.span_label( |
138 | expr.span, | |
139 | "positional arguments must be before named arguments", | |
140 | ); | |
141 | for arg in args.named_args() { | |
142 | if let Some(name) = arg.kind.ident() { | |
143 | err.span_label(name.span.to(arg.expr.span), "named argument"); | |
144 | } | |
74b04a01 XL |
145 | } |
146 | err.emit(); | |
416331ca | 147 | } |
2b03887a | 148 | args.add(FormatArgument { kind: FormatArgumentKind::Normal, expr }); |
416331ca | 149 | } |
1a4d82fc JJ |
150 | } |
151 | } | |
2b03887a | 152 | Ok((fmtstr, args)) |
1a4d82fc JJ |
153 | } |
154 | ||
2b03887a | 155 | pub fn make_format_args( |
416331ca | 156 | ecx: &mut ExtCtxt<'_>, |
2b03887a FG |
157 | efmt: P<Expr>, |
158 | mut args: FormatArguments, | |
416331ca | 159 | append_newline: bool, |
2b03887a | 160 | ) -> Result<FormatArgs, ()> { |
8faf50e0 | 161 | let msg = "format argument must be a string literal"; |
2b03887a | 162 | let unexpanded_fmt_span = efmt.span; |
e1599b0c | 163 | let (fmt_str, fmt_style, fmt_span) = match expr_to_spanned_string(ecx, efmt, msg) { |
8faf50e0 | 164 | Ok(mut fmt) if append_newline => { |
e1599b0c | 165 | fmt.0 = Symbol::intern(&format!("{}\n", fmt.0)); |
8faf50e0 XL |
166 | fmt |
167 | } | |
168 | Ok(fmt) => fmt, | |
0731742a | 169 | Err(err) => { |
c295e0f8 | 170 | if let Some((mut err, suggested)) = err { |
2b03887a | 171 | let sugg_fmt = match args.explicit_args().len() { |
0731742a | 172 | 0 => "{}".to_string(), |
2b03887a | 173 | _ => format!("{}{{}}", "{} ".repeat(args.explicit_args().len())), |
0731742a | 174 | }; |
c295e0f8 XL |
175 | if !suggested { |
176 | err.span_suggestion( | |
2b03887a | 177 | unexpanded_fmt_span.shrink_to_lo(), |
c295e0f8 XL |
178 | "you might be missing a string literal to format with", |
179 | format!("\"{}\", ", sugg_fmt), | |
180 | Applicability::MaybeIncorrect, | |
181 | ); | |
182 | } | |
0731742a XL |
183 | err.emit(); |
184 | } | |
2b03887a | 185 | return Err(()); |
8faf50e0 XL |
186 | } |
187 | }; | |
b7449926 | 188 | |
e1599b0c | 189 | let str_style = match fmt_style { |
2b03887a FG |
190 | rustc_ast::StrStyle::Cooked => None, |
191 | rustc_ast::StrStyle::Raw(raw) => Some(raw as usize), | |
0731742a XL |
192 | }; |
193 | ||
a2a8927a | 194 | let fmt_str = fmt_str.as_str(); // for the suggestions below |
2b03887a | 195 | let fmt_snippet = ecx.source_map().span_to_snippet(unexpanded_fmt_span).ok(); |
f9f354fc XL |
196 | let mut parser = parse::Parser::new( |
197 | fmt_str, | |
198 | str_style, | |
199 | fmt_snippet, | |
200 | append_newline, | |
201 | parse::ParseMode::Format, | |
202 | ); | |
b7449926 | 203 | |
2b03887a | 204 | let mut pieces = Vec::new(); |
b7449926 XL |
205 | while let Some(piece) = parser.next() { |
206 | if !parser.errors.is_empty() { | |
207 | break; | |
208 | } else { | |
2b03887a | 209 | pieces.push(piece); |
b7449926 XL |
210 | } |
211 | } | |
212 | ||
2b03887a FG |
213 | let is_literal = parser.is_literal; |
214 | ||
b7449926 XL |
215 | if !parser.errors.is_empty() { |
216 | let err = parser.errors.remove(0); | |
2b03887a | 217 | let sp = if is_literal { |
04454e1e | 218 | fmt_span.from_inner(InnerSpan::new(err.span.start, err.span.end)) |
136023e0 XL |
219 | } else { |
220 | // The format string could be another macro invocation, e.g.: | |
221 | // format!(concat!("abc", "{}"), 4); | |
222 | // However, `err.span` is an inner span relative to the *result* of | |
223 | // the macro invocation, which is why we would get a nonsensical | |
224 | // result calling `fmt_span.from_inner(err.span)` as above, and | |
225 | // might even end up inside a multibyte character (issue #86085). | |
226 | // Therefore, we conservatively report the error for the entire | |
227 | // argument span here. | |
228 | fmt_span | |
229 | }; | |
dfeec247 | 230 | let mut e = ecx.struct_span_err(sp, &format!("invalid format string: {}", err.description)); |
b7449926 XL |
231 | e.span_label(sp, err.label + " in format string"); |
232 | if let Some(note) = err.note { | |
233 | e.note(¬e); | |
234 | } | |
2b03887a FG |
235 | if let Some((label, span)) = err.secondary_label && is_literal { |
236 | e.span_label(fmt_span.from_inner(InnerSpan::new(span.start, span.end)), label); | |
0731742a | 237 | } |
064997fb FG |
238 | if err.should_be_replaced_with_positional_argument { |
239 | let captured_arg_span = | |
240 | fmt_span.from_inner(InnerSpan::new(err.span.start, err.span.end)); | |
064997fb | 241 | if let Ok(arg) = ecx.source_map().span_to_snippet(captured_arg_span) { |
2b03887a | 242 | let span = match args.unnamed_args().last() { |
064997fb | 243 | Some(arg) => arg.expr.span, |
2b03887a | 244 | None => fmt_span, |
064997fb FG |
245 | }; |
246 | e.multipart_suggestion_verbose( | |
247 | "consider using a positional formatting argument instead", | |
248 | vec![ | |
2b03887a | 249 | (captured_arg_span, args.unnamed_args().len().to_string()), |
064997fb FG |
250 | (span.shrink_to_hi(), format!(", {}", arg)), |
251 | ], | |
252 | Applicability::MachineApplicable, | |
253 | ); | |
254 | } | |
255 | } | |
b7449926 | 256 | e.emit(); |
2b03887a | 257 | return Err(()); |
b7449926 XL |
258 | } |
259 | ||
2b03887a FG |
260 | let to_span = |inner_span: rustc_parse_format::InnerSpan| { |
261 | is_literal.then(|| { | |
262 | fmt_span.from_inner(InnerSpan { start: inner_span.start, end: inner_span.end }) | |
263 | }) | |
264 | }; | |
265 | ||
266 | let mut used = vec![false; args.explicit_args().len()]; | |
267 | let mut invalid_refs = Vec::new(); | |
268 | let mut numeric_refences_to_named_arg = Vec::new(); | |
b7449926 | 269 | |
2b03887a FG |
270 | enum ArgRef<'a> { |
271 | Index(usize), | |
272 | Name(&'a str, Option<Span>), | |
273 | } | |
274 | use ArgRef::*; | |
275 | ||
276 | let mut lookup_arg = |arg: ArgRef<'_>, | |
277 | span: Option<Span>, | |
278 | used_as: PositionUsedAs, | |
279 | kind: FormatArgPositionKind| | |
280 | -> FormatArgPosition { | |
281 | let index = match arg { | |
282 | Index(index) => { | |
283 | if let Some(arg) = args.by_index(index) { | |
284 | used[index] = true; | |
285 | if arg.kind.ident().is_some() { | |
286 | // This was a named argument, but it was used as a positional argument. | |
287 | numeric_refences_to_named_arg.push((index, span, used_as)); | |
288 | } | |
289 | Ok(index) | |
290 | } else { | |
291 | // Doesn't exist as an explicit argument. | |
292 | invalid_refs.push((index, span, used_as, kind)); | |
293 | Err(index) | |
294 | } | |
295 | } | |
296 | Name(name, span) => { | |
297 | let name = Symbol::intern(name); | |
298 | if let Some((index, _)) = args.by_name(name) { | |
299 | // Name found in `args`, so we resolve it to its index. | |
300 | if index < args.explicit_args().len() { | |
301 | // Mark it as used, if it was an explicit argument. | |
302 | used[index] = true; | |
303 | } | |
304 | Ok(index) | |
305 | } else { | |
306 | // Name not found in `args`, so we add it as an implicitly captured argument. | |
307 | let span = span.unwrap_or(fmt_span); | |
308 | let ident = Ident::new(name, span); | |
309 | let expr = if is_literal { | |
310 | ecx.expr_ident(span, ident) | |
311 | } else { | |
312 | // For the moment capturing variables from format strings expanded from macros is | |
313 | // disabled (see RFC #2795) | |
314 | ecx.struct_span_err(span, &format!("there is no argument named `{name}`")) | |
315 | .note(format!("did you intend to capture a variable `{name}` from the surrounding scope?")) | |
316 | .note("to avoid ambiguity, `format_args!` cannot capture variables when the format string is expanded from a macro") | |
317 | .emit(); | |
318 | DummyResult::raw_expr(span, true) | |
319 | }; | |
320 | Ok(args.add(FormatArgument { kind: FormatArgumentKind::Captured(ident), expr })) | |
321 | } | |
322 | } | |
323 | }; | |
324 | FormatArgPosition { index, kind, span } | |
1a4d82fc JJ |
325 | }; |
326 | ||
2b03887a FG |
327 | let mut template = Vec::new(); |
328 | let mut unfinished_literal = String::new(); | |
329 | let mut placeholder_index = 0; | |
dfeec247 | 330 | |
2b03887a FG |
331 | for piece in pieces { |
332 | match piece { | |
333 | parse::Piece::String(s) => { | |
334 | unfinished_literal.push_str(s); | |
335 | } | |
336 | parse::Piece::NextArgument(parse::Argument { position, position_span, format }) => { | |
337 | if !unfinished_literal.is_empty() { | |
338 | template.push(FormatArgsPiece::Literal(Symbol::intern(&unfinished_literal))); | |
339 | unfinished_literal.clear(); | |
340 | } | |
abe05a73 | 341 | |
2b03887a FG |
342 | let span = parser.arg_places.get(placeholder_index).and_then(|&s| to_span(s)); |
343 | placeholder_index += 1; | |
344 | ||
345 | let position_span = to_span(position_span); | |
346 | let argument = match position { | |
347 | parse::ArgumentImplicitlyIs(i) => lookup_arg( | |
348 | Index(i), | |
349 | position_span, | |
350 | Placeholder(span), | |
351 | FormatArgPositionKind::Implicit, | |
352 | ), | |
353 | parse::ArgumentIs(i) => lookup_arg( | |
354 | Index(i), | |
355 | position_span, | |
356 | Placeholder(span), | |
357 | FormatArgPositionKind::Number, | |
358 | ), | |
359 | parse::ArgumentNamed(name) => lookup_arg( | |
360 | Name(name, position_span), | |
361 | position_span, | |
362 | Placeholder(span), | |
363 | FormatArgPositionKind::Named, | |
364 | ), | |
365 | }; | |
5bcae85e | 366 | |
2b03887a FG |
367 | let alignment = match format.align { |
368 | parse::AlignUnknown => None, | |
369 | parse::AlignLeft => Some(FormatAlignment::Left), | |
370 | parse::AlignRight => Some(FormatAlignment::Right), | |
371 | parse::AlignCenter => Some(FormatAlignment::Center), | |
372 | }; | |
b7449926 | 373 | |
2b03887a FG |
374 | let format_trait = match format.ty { |
375 | "" => FormatTrait::Display, | |
376 | "?" => FormatTrait::Debug, | |
377 | "e" => FormatTrait::LowerExp, | |
378 | "E" => FormatTrait::UpperExp, | |
379 | "o" => FormatTrait::Octal, | |
380 | "p" => FormatTrait::Pointer, | |
381 | "b" => FormatTrait::Binary, | |
382 | "x" => FormatTrait::LowerHex, | |
383 | "X" => FormatTrait::UpperHex, | |
384 | _ => { | |
385 | invalid_placeholder_type_error(ecx, format.ty, format.ty_span, fmt_span); | |
386 | FormatTrait::Display | |
387 | } | |
388 | }; | |
389 | ||
390 | let precision_span = format.precision_span.and_then(to_span); | |
391 | let precision = match format.precision { | |
392 | parse::CountIs(n) => Some(FormatCount::Literal(n)), | |
393 | parse::CountIsName(name, name_span) => Some(FormatCount::Argument(lookup_arg( | |
394 | Name(name, to_span(name_span)), | |
395 | precision_span, | |
396 | Precision, | |
397 | FormatArgPositionKind::Named, | |
398 | ))), | |
399 | parse::CountIsParam(i) => Some(FormatCount::Argument(lookup_arg( | |
400 | Index(i), | |
401 | precision_span, | |
402 | Precision, | |
403 | FormatArgPositionKind::Number, | |
404 | ))), | |
405 | parse::CountIsStar(i) => Some(FormatCount::Argument(lookup_arg( | |
406 | Index(i), | |
407 | precision_span, | |
408 | Precision, | |
409 | FormatArgPositionKind::Implicit, | |
410 | ))), | |
411 | parse::CountImplied => None, | |
412 | }; | |
413 | ||
414 | let width_span = format.width_span.and_then(to_span); | |
415 | let width = match format.width { | |
416 | parse::CountIs(n) => Some(FormatCount::Literal(n)), | |
417 | parse::CountIsName(name, name_span) => Some(FormatCount::Argument(lookup_arg( | |
418 | Name(name, to_span(name_span)), | |
419 | width_span, | |
420 | Width, | |
421 | FormatArgPositionKind::Named, | |
422 | ))), | |
423 | parse::CountIsParam(i) => Some(FormatCount::Argument(lookup_arg( | |
424 | Index(i), | |
425 | width_span, | |
426 | Width, | |
427 | FormatArgPositionKind::Number, | |
428 | ))), | |
429 | parse::CountIsStar(_) => unreachable!(), | |
430 | parse::CountImplied => None, | |
431 | }; | |
432 | ||
433 | template.push(FormatArgsPiece::Placeholder(FormatPlaceholder { | |
434 | argument, | |
435 | span, | |
436 | format_trait, | |
437 | format_options: FormatOptions { | |
438 | fill: format.fill, | |
439 | alignment, | |
440 | flags: format.flags, | |
441 | precision, | |
442 | width, | |
443 | }, | |
444 | })); | |
445 | } | |
5bcae85e SL |
446 | } |
447 | } | |
448 | ||
2b03887a FG |
449 | if !unfinished_literal.is_empty() { |
450 | template.push(FormatArgsPiece::Literal(Symbol::intern(&unfinished_literal))); | |
1a4d82fc JJ |
451 | } |
452 | ||
2b03887a FG |
453 | if !invalid_refs.is_empty() { |
454 | report_invalid_references(ecx, &invalid_refs, &template, fmt_span, &args, parser); | |
abe05a73 XL |
455 | } |
456 | ||
2b03887a | 457 | let unused = used |
dfeec247 XL |
458 | .iter() |
459 | .enumerate() | |
2b03887a | 460 | .filter(|&(_, used)| !used) |
dfeec247 | 461 | .map(|(i, _)| { |
2b03887a | 462 | let msg = if let FormatArgumentKind::Named(_) = args.explicit_args()[i].kind { |
dfeec247 XL |
463 | "named argument never used" |
464 | } else { | |
dfeec247 XL |
465 | "argument never used" |
466 | }; | |
2b03887a | 467 | (args.explicit_args()[i].expr.span, msg) |
dfeec247 XL |
468 | }) |
469 | .collect::<Vec<_>>(); | |
b7449926 | 470 | |
2b03887a FG |
471 | if !unused.is_empty() { |
472 | // If there's a lot of unused arguments, | |
473 | // let's check if this format arguments looks like another syntax (printf / shell). | |
474 | let detect_foreign_fmt = unused.len() > args.explicit_args().len() / 2; | |
475 | report_missing_placeholders(ecx, unused, detect_foreign_fmt, str_style, fmt_str, fmt_span); | |
476 | } | |
476ff2be | 477 | |
2b03887a FG |
478 | // Only check for unused named argument names if there are no other errors to avoid causing |
479 | // too much noise in output errors, such as when a named argument is entirely unused. | |
480 | if invalid_refs.is_empty() && ecx.sess.err_count() == 0 { | |
481 | for &(index, span, used_as) in &numeric_refences_to_named_arg { | |
482 | let (position_sp_to_replace, position_sp_for_msg) = match used_as { | |
483 | Placeholder(pspan) => (span, pspan), | |
484 | Precision => { | |
485 | // Strip the leading `.` for precision. | |
486 | let span = span.map(|span| span.with_lo(span.lo() + BytePos(1))); | |
487 | (span, span) | |
0731742a | 488 | } |
2b03887a FG |
489 | Width => (span, span), |
490 | }; | |
491 | let arg_name = args.explicit_args()[index].kind.ident().unwrap(); | |
492 | ecx.buffered_early_lint.push(BufferedEarlyLint { | |
493 | span: arg_name.span.into(), | |
494 | msg: format!("named argument `{}` is not used by name", arg_name.name).into(), | |
495 | node_id: rustc_ast::CRATE_NODE_ID, | |
496 | lint_id: LintId::of(&NAMED_ARGUMENTS_USED_POSITIONALLY), | |
497 | diagnostic: BuiltinLintDiagnostics::NamedArgumentUsedPositionally { | |
498 | position_sp_to_replace, | |
499 | position_sp_for_msg, | |
500 | named_arg_sp: arg_name.span, | |
501 | named_arg_name: arg_name.name.to_string(), | |
502 | is_formatting_arg: matches!(used_as, Width | Precision), | |
503 | }, | |
504 | }); | |
505 | } | |
506 | } | |
476ff2be | 507 | |
2b03887a FG |
508 | Ok(FormatArgs { span: fmt_span, template, arguments: args }) |
509 | } | |
476ff2be | 510 | |
2b03887a FG |
511 | fn invalid_placeholder_type_error( |
512 | ecx: &ExtCtxt<'_>, | |
513 | ty: &str, | |
514 | ty_span: Option<rustc_parse_format::InnerSpan>, | |
515 | fmt_span: Span, | |
516 | ) { | |
517 | let sp = ty_span.map(|sp| fmt_span.from_inner(InnerSpan::new(sp.start, sp.end))); | |
518 | let mut err = | |
519 | ecx.struct_span_err(sp.unwrap_or(fmt_span), &format!("unknown format trait `{}`", ty)); | |
520 | err.note( | |
521 | "the only appropriate formatting traits are:\n\ | |
522 | - ``, which uses the `Display` trait\n\ | |
523 | - `?`, which uses the `Debug` trait\n\ | |
524 | - `e`, which uses the `LowerExp` trait\n\ | |
525 | - `E`, which uses the `UpperExp` trait\n\ | |
526 | - `o`, which uses the `Octal` trait\n\ | |
527 | - `p`, which uses the `Pointer` trait\n\ | |
528 | - `b`, which uses the `Binary` trait\n\ | |
529 | - `x`, which uses the `LowerHex` trait\n\ | |
530 | - `X`, which uses the `UpperHex` trait", | |
531 | ); | |
532 | if let Some(sp) = sp { | |
533 | for (fmt, name) in &[ | |
534 | ("", "Display"), | |
535 | ("?", "Debug"), | |
536 | ("e", "LowerExp"), | |
537 | ("E", "UpperExp"), | |
538 | ("o", "Octal"), | |
539 | ("p", "Pointer"), | |
540 | ("b", "Binary"), | |
541 | ("x", "LowerHex"), | |
542 | ("X", "UpperHex"), | |
543 | ] { | |
544 | err.tool_only_span_suggestion( | |
545 | sp, | |
546 | &format!("use the `{}` trait", name), | |
547 | *fmt, | |
548 | Applicability::MaybeIncorrect, | |
549 | ); | |
550 | } | |
551 | } | |
552 | err.emit(); | |
553 | } | |
476ff2be | 554 | |
2b03887a FG |
555 | fn report_missing_placeholders( |
556 | ecx: &mut ExtCtxt<'_>, | |
557 | unused: Vec<(Span, &str)>, | |
558 | detect_foreign_fmt: bool, | |
559 | str_style: Option<usize>, | |
560 | fmt_str: &str, | |
561 | fmt_span: Span, | |
562 | ) { | |
563 | let mut diag = if let &[(span, msg)] = &unused[..] { | |
564 | let mut diag = ecx.struct_span_err(span, msg); | |
565 | diag.span_label(span, msg); | |
566 | diag | |
567 | } else { | |
568 | let mut diag = ecx.struct_span_err( | |
569 | unused.iter().map(|&(sp, _)| sp).collect::<Vec<Span>>(), | |
570 | "multiple unused formatting arguments", | |
571 | ); | |
572 | diag.span_label(fmt_span, "multiple missing formatting specifiers"); | |
573 | for &(span, msg) in &unused { | |
574 | diag.span_label(span, msg); | |
575 | } | |
576 | diag | |
577 | }; | |
476ff2be | 578 | |
2b03887a FG |
579 | // Used to ensure we only report translations for *one* kind of foreign format. |
580 | let mut found_foreign = false; | |
581 | ||
582 | // Decide if we want to look for foreign formatting directives. | |
583 | if detect_foreign_fmt { | |
584 | use super::format_foreign as foreign; | |
585 | ||
586 | // The set of foreign substitutions we've explained. This prevents spamming the user | |
587 | // with `%d should be written as {}` over and over again. | |
588 | let mut explained = FxHashSet::default(); | |
589 | ||
590 | macro_rules! check_foreign { | |
591 | ($kind:ident) => {{ | |
592 | let mut show_doc_note = false; | |
593 | ||
594 | let mut suggestions = vec![]; | |
595 | // account for `"` and account for raw strings `r#` | |
596 | let padding = str_style.map(|i| i + 2).unwrap_or(1); | |
597 | for sub in foreign::$kind::iter_subs(fmt_str, padding) { | |
598 | let (trn, success) = match sub.translate() { | |
599 | Ok(trn) => (trn, true), | |
600 | Err(Some(msg)) => (msg, false), | |
601 | ||
602 | // If it has no translation, don't call it out specifically. | |
603 | _ => continue, | |
604 | }; | |
605 | ||
606 | let pos = sub.position(); | |
607 | let sub = String::from(sub.as_str()); | |
608 | if explained.contains(&sub) { | |
609 | continue; | |
610 | } | |
611 | explained.insert(sub.clone()); | |
476ff2be | 612 | |
2b03887a FG |
613 | if !found_foreign { |
614 | found_foreign = true; | |
615 | show_doc_note = true; | |
616 | } | |
476ff2be | 617 | |
2b03887a FG |
618 | if let Some(inner_sp) = pos { |
619 | let sp = fmt_span.from_inner(inner_sp); | |
476ff2be | 620 | |
2b03887a FG |
621 | if success { |
622 | suggestions.push((sp, trn)); | |
623 | } else { | |
624 | diag.span_note( | |
625 | sp, | |
626 | &format!("format specifiers use curly braces, and {}", trn), | |
627 | ); | |
476ff2be | 628 | } |
2b03887a FG |
629 | } else { |
630 | if success { | |
631 | diag.help(&format!("`{}` should be written as `{}`", sub, trn)); | |
8faf50e0 | 632 | } else { |
2b03887a | 633 | diag.note(&format!("`{}` should use curly braces, and {}", sub, trn)); |
8faf50e0 | 634 | } |
476ff2be | 635 | } |
2b03887a | 636 | } |
476ff2be | 637 | |
2b03887a FG |
638 | if show_doc_note { |
639 | diag.note(concat!( | |
640 | stringify!($kind), | |
641 | " formatting not supported; see the documentation for `std::fmt`", | |
642 | )); | |
643 | } | |
644 | if suggestions.len() > 0 { | |
645 | diag.multipart_suggestion( | |
646 | "format specifiers use curly braces", | |
647 | suggestions, | |
648 | Applicability::MachineApplicable, | |
649 | ); | |
650 | } | |
651 | }}; | |
8faf50e0 | 652 | } |
476ff2be | 653 | |
2b03887a FG |
654 | check_foreign!(printf); |
655 | if !found_foreign { | |
656 | check_foreign!(shell); | |
657 | } | |
658 | } | |
659 | if !found_foreign && unused.len() == 1 { | |
660 | diag.span_label(fmt_span, "formatting specifier missing"); | |
1a4d82fc JJ |
661 | } |
662 | ||
2b03887a | 663 | diag.emit(); |
1a4d82fc | 664 | } |
5099ac24 | 665 | |
2b03887a FG |
666 | /// Handle invalid references to positional arguments. Output different |
667 | /// errors for the case where all arguments are positional and for when | |
668 | /// there are named arguments or numbered positional arguments in the | |
669 | /// format string. | |
670 | fn report_invalid_references( | |
671 | ecx: &mut ExtCtxt<'_>, | |
672 | invalid_refs: &[(usize, Option<Span>, PositionUsedAs, FormatArgPositionKind)], | |
673 | template: &[FormatArgsPiece], | |
674 | fmt_span: Span, | |
675 | args: &FormatArguments, | |
676 | parser: parse::Parser<'_>, | |
677 | ) { | |
678 | let num_args_desc = match args.explicit_args().len() { | |
679 | 0 => "no arguments were given".to_string(), | |
680 | 1 => "there is 1 argument".to_string(), | |
681 | n => format!("there are {} arguments", n), | |
682 | }; | |
683 | ||
684 | let mut e; | |
5099ac24 | 685 | |
2b03887a FG |
686 | if template.iter().all(|piece| match piece { |
687 | FormatArgsPiece::Placeholder(FormatPlaceholder { | |
688 | argument: FormatArgPosition { kind: FormatArgPositionKind::Number, .. }, | |
689 | .. | |
690 | }) => false, | |
691 | FormatArgsPiece::Placeholder(FormatPlaceholder { | |
692 | format_options: | |
693 | FormatOptions { | |
694 | precision: | |
695 | Some(FormatCount::Argument(FormatArgPosition { | |
696 | kind: FormatArgPositionKind::Number, | |
697 | .. | |
698 | })), | |
699 | .. | |
700 | } | |
701 | | FormatOptions { | |
702 | width: | |
703 | Some(FormatCount::Argument(FormatArgPosition { | |
704 | kind: FormatArgPositionKind::Number, | |
705 | .. | |
706 | })), | |
707 | .. | |
708 | }, | |
709 | .. | |
710 | }) => false, | |
711 | _ => true, | |
712 | }) { | |
713 | // There are no numeric positions. | |
714 | // Collect all the implicit positions: | |
715 | let mut spans = Vec::new(); | |
716 | let mut num_placeholders = 0; | |
717 | for piece in template { | |
718 | let mut placeholder = None; | |
719 | // `{arg:.*}` | |
720 | if let FormatArgsPiece::Placeholder(FormatPlaceholder { | |
721 | format_options: | |
722 | FormatOptions { | |
723 | precision: | |
724 | Some(FormatCount::Argument(FormatArgPosition { | |
725 | span, | |
726 | kind: FormatArgPositionKind::Implicit, | |
727 | .. | |
728 | })), | |
729 | .. | |
730 | }, | |
731 | .. | |
732 | }) = piece | |
733 | { | |
734 | placeholder = *span; | |
735 | num_placeholders += 1; | |
5099ac24 | 736 | } |
2b03887a FG |
737 | // `{}` |
738 | if let FormatArgsPiece::Placeholder(FormatPlaceholder { | |
739 | argument: FormatArgPosition { kind: FormatArgPositionKind::Implicit, .. }, | |
740 | span, | |
741 | .. | |
742 | }) = piece | |
743 | { | |
744 | placeholder = *span; | |
745 | num_placeholders += 1; | |
746 | } | |
747 | // For `{:.*}`, we only push one span. | |
748 | spans.extend(placeholder); | |
5099ac24 | 749 | } |
2b03887a FG |
750 | let span = if spans.is_empty() { |
751 | MultiSpan::from_span(fmt_span) | |
752 | } else { | |
753 | MultiSpan::from_spans(spans) | |
754 | }; | |
755 | e = ecx.struct_span_err( | |
756 | span, | |
757 | &format!( | |
758 | "{} positional argument{} in format string, but {}", | |
759 | num_placeholders, | |
760 | pluralize!(num_placeholders), | |
761 | num_args_desc, | |
762 | ), | |
763 | ); | |
764 | for arg in args.explicit_args() { | |
765 | e.span_label(arg.expr.span, ""); | |
766 | } | |
767 | // Point out `{:.*}` placeholders: those take an extra argument. | |
768 | let mut has_precision_star = false; | |
769 | for piece in template { | |
770 | if let FormatArgsPiece::Placeholder(FormatPlaceholder { | |
771 | format_options: | |
772 | FormatOptions { | |
773 | precision: | |
774 | Some(FormatCount::Argument(FormatArgPosition { | |
775 | index, | |
776 | span: Some(span), | |
777 | kind: FormatArgPositionKind::Implicit, | |
778 | .. | |
779 | })), | |
780 | .. | |
781 | }, | |
782 | .. | |
783 | }) = piece | |
784 | { | |
785 | let (Ok(index) | Err(index)) = index; | |
786 | has_precision_star = true; | |
787 | e.span_label( | |
788 | *span, | |
789 | &format!( | |
790 | "this precision flag adds an extra required argument at position {}, which is why there {} expected", | |
791 | index, | |
792 | if num_placeholders == 1 { | |
793 | "is 1 argument".to_string() | |
794 | } else { | |
795 | format!("are {} arguments", num_placeholders) | |
796 | }, | |
797 | ), | |
798 | ); | |
799 | } | |
800 | } | |
801 | if has_precision_star { | |
802 | e.note("positional arguments are zero-based"); | |
5099ac24 | 803 | } |
2b03887a FG |
804 | } else { |
805 | let mut indexes: Vec<_> = invalid_refs.iter().map(|&(index, _, _, _)| index).collect(); | |
806 | // Avoid `invalid reference to positional arguments 7 and 7 (there is 1 argument)` | |
807 | // for `println!("{7:7$}", 1);` | |
808 | indexes.sort(); | |
809 | indexes.dedup(); | |
810 | let span: MultiSpan = if !parser.is_literal || parser.arg_places.is_empty() { | |
811 | MultiSpan::from_span(fmt_span) | |
812 | } else { | |
813 | MultiSpan::from_spans(invalid_refs.iter().filter_map(|&(_, span, _, _)| span).collect()) | |
814 | }; | |
815 | let arg_list = if let &[index] = &indexes[..] { | |
816 | format!("argument {index}") | |
817 | } else { | |
818 | let tail = indexes.pop().unwrap(); | |
819 | format!( | |
820 | "arguments {head} and {tail}", | |
821 | head = indexes.into_iter().map(|i| i.to_string()).collect::<Vec<_>>().join(", ") | |
822 | ) | |
823 | }; | |
824 | e = ecx.struct_span_err( | |
825 | span, | |
826 | &format!("invalid reference to positional {} ({})", arg_list, num_args_desc), | |
827 | ); | |
828 | e.note("positional arguments are zero-based"); | |
829 | } | |
5099ac24 | 830 | |
2b03887a FG |
831 | if template.iter().any(|piece| match piece { |
832 | FormatArgsPiece::Placeholder(FormatPlaceholder { format_options: f, .. }) => { | |
833 | *f != FormatOptions::default() | |
5099ac24 | 834 | } |
2b03887a FG |
835 | _ => false, |
836 | }) { | |
837 | e.note("for information about formatting flags, visit https://doc.rust-lang.org/std/fmt/index.html"); | |
838 | } | |
839 | ||
840 | e.emit(); | |
841 | } | |
5099ac24 | 842 | |
2b03887a FG |
843 | fn expand_format_args_impl<'cx>( |
844 | ecx: &'cx mut ExtCtxt<'_>, | |
845 | mut sp: Span, | |
846 | tts: TokenStream, | |
847 | nl: bool, | |
848 | ) -> Box<dyn base::MacResult + 'cx> { | |
849 | sp = ecx.with_def_site_ctxt(sp); | |
850 | match parse_args(ecx, sp, tts) { | |
851 | Ok((efmt, args)) => { | |
852 | if let Ok(format_args) = make_format_args(ecx, efmt, args, nl) { | |
853 | MacEager::expr(expand_parsed_format_args(ecx, format_args)) | |
854 | } else { | |
855 | MacEager::expr(DummyResult::raw_expr(sp, true)) | |
856 | } | |
857 | } | |
858 | Err(mut err) => { | |
859 | err.emit(); | |
860 | DummyResult::any(sp) | |
5099ac24 FG |
861 | } |
862 | } | |
2b03887a FG |
863 | } |
864 | ||
865 | pub fn expand_format_args<'cx>( | |
866 | ecx: &'cx mut ExtCtxt<'_>, | |
867 | sp: Span, | |
868 | tts: TokenStream, | |
869 | ) -> Box<dyn base::MacResult + 'cx> { | |
870 | expand_format_args_impl(ecx, sp, tts, false) | |
871 | } | |
5099ac24 | 872 | |
2b03887a FG |
873 | pub fn expand_format_args_nl<'cx>( |
874 | ecx: &'cx mut ExtCtxt<'_>, | |
875 | sp: Span, | |
876 | tts: TokenStream, | |
877 | ) -> Box<dyn base::MacResult + 'cx> { | |
878 | expand_format_args_impl(ecx, sp, tts, true) | |
5099ac24 | 879 | } |