| use ArgumentType::*; |
| use Position::*; |
| |
| use rustc_ast as ast; |
| use rustc_ast::ptr::P; |
| use rustc_ast::tokenstream::TokenStream; |
| use rustc_ast::visit::{self, Visitor}; |
| use rustc_ast::{token, BlockCheckMode, UnsafeSource}; |
| use rustc_data_structures::fx::{FxHashMap, FxHashSet}; |
| use rustc_errors::{pluralize, Applicability, MultiSpan, PResult}; |
| use rustc_expand::base::{self, *}; |
| use rustc_parse_format as parse; |
| use rustc_span::symbol::{sym, Ident, Symbol}; |
| use rustc_span::{BytePos, InnerSpan, Span}; |
| use smallvec::SmallVec; |
| |
| use rustc_lint_defs::builtin::NAMED_ARGUMENTS_USED_POSITIONALLY; |
| use rustc_lint_defs::{BufferedEarlyLint, BuiltinLintDiagnostics, LintId}; |
| use rustc_parse_format::Count; |
| use std::borrow::Cow; |
| use std::collections::hash_map::Entry; |
| |
| #[derive(PartialEq)] |
| enum ArgumentType { |
| Placeholder(&'static str), |
| Count, |
| } |
| |
| enum Position { |
| Exact(usize), |
| Capture(usize), |
| Named(Symbol, InnerSpan), |
| } |
| |
| /// Indicates how positional named argument (i.e. an named argument which is used by position |
| /// instead of by name) is used in format string |
| /// * `Arg` is the actual argument to print |
| /// * `Width` is width format argument |
| /// * `Precision` is precion format argument |
| /// Example: `{Arg:Width$.Precision$} |
| #[derive(Debug, Eq, PartialEq)] |
| enum PositionalNamedArgType { |
| Arg, |
| Width, |
| Precision, |
| } |
| |
| /// Contains information necessary to create a lint for a positional named argument |
| #[derive(Debug)] |
| struct PositionalNamedArg { |
| ty: PositionalNamedArgType, |
| /// The piece of the using this argument (multiple pieces can use the same argument) |
| cur_piece: usize, |
| /// The InnerSpan for in the string to be replaced with the named argument |
| /// This will be None when the position is implicit |
| inner_span_to_replace: Option<rustc_parse_format::InnerSpan>, |
| /// The name to use instead of the position |
| replacement: Symbol, |
| /// The span for the positional named argument (so the lint can point a message to it) |
| positional_named_arg_span: Span, |
| has_formatting: bool, |
| } |
| |
| impl PositionalNamedArg { |
| /// Determines: |
| /// 1) span to be replaced with the name of the named argument and |
| /// 2) span to be underlined for error messages |
| fn get_positional_arg_spans(&self, cx: &Context<'_, '_>) -> (Option<Span>, Option<Span>) { |
| if let Some(inner_span) = &self.inner_span_to_replace { |
| let span = |
| cx.fmtsp.from_inner(InnerSpan { start: inner_span.start, end: inner_span.end }); |
| (Some(span), Some(span)) |
| } else if self.ty == PositionalNamedArgType::Arg { |
| // In the case of a named argument whose position is implicit, if the argument *has* |
| // formatting, there will not be a span to replace. Instead, we insert the name after |
| // the `{`, which will be the first character of arg_span. If the argument does *not* |
| // have formatting, there may or may not be a span to replace. This is because |
| // whitespace is allowed in arguments without formatting (such as `format!("{ }", 1);`) |
| // but is not allowed in arguments with formatting (an error will be generated in cases |
| // like `format!("{ :1.1}", 1.0f32);`. |
| // For the message span, if there is formatting, we want to use the opening `{` and the |
| // next character, which will the `:` indicating the start of formatting. If there is |
| // not any formatting, we want to underline the entire span. |
| cx.arg_spans.get(self.cur_piece).map_or((None, None), |arg_span| { |
| if self.has_formatting { |
| ( |
| Some(arg_span.with_lo(arg_span.lo() + BytePos(1)).shrink_to_lo()), |
| Some(arg_span.with_hi(arg_span.lo() + BytePos(2))), |
| ) |
| } else { |
| let replace_start = arg_span.lo() + BytePos(1); |
| let replace_end = arg_span.hi() - BytePos(1); |
| let to_replace = arg_span.with_lo(replace_start).with_hi(replace_end); |
| (Some(to_replace), Some(*arg_span)) |
| } |
| }) |
| } else { |
| (None, None) |
| } |
| } |
| } |
| |
| /// Encapsulates all the named arguments that have been used positionally |
| #[derive(Debug)] |
| struct PositionalNamedArgsLint { |
| positional_named_args: Vec<PositionalNamedArg>, |
| } |
| |
| impl PositionalNamedArgsLint { |
| /// For a given positional argument, check if the index is for a named argument. |
| /// |
| /// Since positional arguments are required to come before named arguments, if the positional |
| /// index is greater than or equal to the start of named arguments, we know it's a named |
| /// argument used positionally. |
| /// |
| /// Example: |
| /// println!("{} {} {2}", 0, a=1, b=2); |
| /// |
| /// In this case, the first piece (`{}`) would be ArgumentImplicitlyIs with an index of 0. The |
| /// total number of arguments is 3 and the number of named arguments is 2, so the start of named |
| /// arguments is index 1. Therefore, the index of 0 is okay. |
| /// |
| /// The second piece (`{}`) would be ArgumentImplicitlyIs with an index of 1, which is the start |
| /// of named arguments, and so we should add a lint to use the named argument `a`. |
| /// |
| /// The third piece (`{2}`) would be ArgumentIs with an index of 2, which is greater than the |
| /// start of named arguments, and so we should add a lint to use the named argument `b`. |
| /// |
| /// This same check also works for width and precision formatting when either or both are |
| /// CountIsParam, which contains an index into the arguments. |
| fn maybe_add_positional_named_arg( |
| &mut self, |
| current_positional_arg: usize, |
| total_args_length: usize, |
| format_argument_index: usize, |
| ty: PositionalNamedArgType, |
| cur_piece: usize, |
| inner_span_to_replace: Option<rustc_parse_format::InnerSpan>, |
| names: &FxHashMap<Symbol, (usize, Span)>, |
| has_formatting: bool, |
| ) { |
| let start_of_named_args = total_args_length - names.len(); |
| if current_positional_arg >= start_of_named_args { |
| self.maybe_push( |
| format_argument_index, |
| ty, |
| cur_piece, |
| inner_span_to_replace, |
| names, |
| has_formatting, |
| ) |
| } |
| } |
| |
| /// Try constructing a PositionalNamedArg struct and pushing it into the vec of positional |
| /// named arguments. If a named arg associated with `format_argument_index` cannot be found, |
| /// a new item will not be added as the lint cannot be emitted in this case. |
| fn maybe_push( |
| &mut self, |
| format_argument_index: usize, |
| ty: PositionalNamedArgType, |
| cur_piece: usize, |
| inner_span_to_replace: Option<rustc_parse_format::InnerSpan>, |
| names: &FxHashMap<Symbol, (usize, Span)>, |
| has_formatting: bool, |
| ) { |
| let named_arg = names |
| .iter() |
| .find(|&(_, &(index, _))| index == format_argument_index) |
| .map(|found| found.clone()); |
| |
| if let Some((&replacement, &(_, positional_named_arg_span))) = named_arg { |
| // In FormatSpec, `precision_span` starts at the leading `.`, which we want to keep in |
| // the lint suggestion, so increment `start` by 1 when `PositionalArgumentType` is |
| // `Precision`. |
| let inner_span_to_replace = if ty == PositionalNamedArgType::Precision { |
| inner_span_to_replace |
| .map(|is| rustc_parse_format::InnerSpan { start: is.start + 1, end: is.end }) |
| } else { |
| inner_span_to_replace |
| }; |
| self.positional_named_args.push(PositionalNamedArg { |
| ty, |
| cur_piece, |
| inner_span_to_replace, |
| replacement, |
| positional_named_arg_span, |
| has_formatting, |
| }); |
| } |
| } |
| } |
| |
| struct Context<'a, 'b> { |
| ecx: &'a mut ExtCtxt<'b>, |
| /// The macro's call site. References to unstable formatting internals must |
| /// use this span to pass the stability checker. |
| macsp: Span, |
| /// The span of the format string literal. |
| fmtsp: Span, |
| |
| /// List of parsed argument expressions. |
| /// Named expressions are resolved early, and are appended to the end of |
| /// argument expressions. |
| /// |
| /// Example showing the various data structures in motion: |
| /// |
| /// * Original: `"{foo:o} {:o} {foo:x} {0:x} {1:o} {:x} {1:x} {0:o}"` |
| /// * Implicit argument resolution: `"{foo:o} {0:o} {foo:x} {0:x} {1:o} {1:x} {1:x} {0:o}"` |
| /// * Name resolution: `"{2:o} {0:o} {2:x} {0:x} {1:o} {1:x} {1:x} {0:o}"` |
| /// * `arg_types` (in JSON): `[[0, 1, 0], [0, 1, 1], [0, 1]]` |
| /// * `arg_unique_types` (in simplified JSON): `[["o", "x"], ["o", "x"], ["o", "x"]]` |
| /// * `names` (in JSON): `{"foo": 2}` |
| args: Vec<P<ast::Expr>>, |
| /// The number of arguments that were added by implicit capturing. |
| num_captured_args: usize, |
| /// Placeholder slot numbers indexed by argument. |
| arg_types: Vec<Vec<usize>>, |
| /// Unique format specs seen for each argument. |
| arg_unique_types: Vec<Vec<ArgumentType>>, |
| /// Map from named arguments to their resolved indices. |
| names: FxHashMap<Symbol, (usize, Span)>, |
| |
| /// The latest consecutive literal strings, or empty if there weren't any. |
| literal: String, |
| |
| /// Collection of the compiled `rt::Argument` structures |
| pieces: Vec<P<ast::Expr>>, |
| /// Collection of string literals |
| str_pieces: Vec<P<ast::Expr>>, |
| /// Stays `true` if all formatting parameters are default (as in "{}{}"). |
| all_pieces_simple: bool, |
| |
| /// Mapping between positional argument references and indices into the |
| /// final generated static argument array. We record the starting indices |
| /// corresponding to each positional argument, and number of references |
| /// consumed so far for each argument, to facilitate correct `Position` |
| /// mapping in `build_piece`. In effect this can be seen as a "flattened" |
| /// version of `arg_unique_types`. |
| /// |
| /// Again with the example described above in docstring for `args`: |
| /// |
| /// * `arg_index_map` (in JSON): `[[0, 1, 0], [2, 3, 3], [4, 5]]` |
| arg_index_map: Vec<Vec<usize>>, |
| |
| /// Starting offset of count argument slots. |
| count_args_index_offset: usize, |
| |
| /// Count argument slots and tracking data structures. |
| /// Count arguments are separately tracked for de-duplication in case |
| /// multiple references are made to one argument. For example, in this |
| /// format string: |
| /// |
| /// * Original: `"{:.*} {:.foo$} {1:.*} {:.0$}"` |
| /// * Implicit argument resolution: `"{1:.0$} {2:.foo$} {1:.3$} {4:.0$}"` |
| /// * Name resolution: `"{1:.0$} {2:.5$} {1:.3$} {4:.0$}"` |
| /// * `count_positions` (in JSON): `{0: 0, 5: 1, 3: 2}` |
| /// * `count_args`: `vec![0, 5, 3]` |
| count_args: Vec<usize>, |
| /// Relative slot numbers for count arguments. |
| count_positions: FxHashMap<usize, usize>, |
| /// Number of count slots assigned. |
| count_positions_count: usize, |
| |
| /// Current position of the implicit positional arg pointer, as if it |
| /// still existed in this phase of processing. |
| /// Used only for `all_pieces_simple` tracking in `build_piece`. |
| curarg: usize, |
| /// Current piece being evaluated, used for error reporting. |
| curpiece: usize, |
| /// Keep track of invalid references to positional arguments. |
| invalid_refs: Vec<(usize, usize)>, |
| /// Spans of all the formatting arguments, in order. |
| arg_spans: Vec<Span>, |
| /// All the formatting arguments that have formatting flags set, in order for diagnostics. |
| arg_with_formatting: Vec<parse::FormatSpec<'a>>, |
| |
| /// Whether this format string came from a string literal, as opposed to a macro. |
| is_literal: bool, |
| unused_names_lint: PositionalNamedArgsLint, |
| } |
| |
| pub struct FormatArg { |
| expr: P<ast::Expr>, |
| named: bool, |
| } |
| |
| /// Parses the arguments from the given list of tokens, returning the diagnostic |
| /// if there's a parse error so we can continue parsing other format! |
| /// expressions. |
| /// |
| /// If parsing succeeds, the return value is: |
| /// |
| /// ```text |
| /// Some((fmtstr, parsed arguments, index map for named arguments)) |
| /// ``` |
| fn parse_args<'a>( |
| ecx: &mut ExtCtxt<'a>, |
| sp: Span, |
| tts: TokenStream, |
| ) -> PResult<'a, (P<ast::Expr>, Vec<FormatArg>, FxHashMap<Symbol, (usize, Span)>)> { |
| let mut args = Vec::<FormatArg>::new(); |
| let mut names = FxHashMap::<Symbol, (usize, Span)>::default(); |
| |
| let mut p = ecx.new_parser_from_tts(tts); |
| |
| if p.token == token::Eof { |
| return Err(ecx.struct_span_err(sp, "requires at least a format string argument")); |
| } |
| |
| let first_token = &p.token; |
| let fmtstr = match first_token.kind { |
| token::TokenKind::Literal(token::Lit { |
| kind: token::LitKind::Str | token::LitKind::StrRaw(_), |
| .. |
| }) => { |
| // If the first token is a string literal, then a format expression |
| // is constructed from it. |
| // |
| // This allows us to properly handle cases when the first comma |
| // after the format string is mistakenly replaced with any operator, |
| // which cause the expression parser to eat too much tokens. |
| p.parse_literal_maybe_minus()? |
| } |
| _ => { |
| // Otherwise, we fall back to the expression parser. |
| p.parse_expr()? |
| } |
| }; |
| |
| let mut first = true; |
| let mut named = false; |
| |
| while p.token != token::Eof { |
| if !p.eat(&token::Comma) { |
| if first { |
| p.clear_expected_tokens(); |
| } |
| |
| match p.expect(&token::Comma) { |
| Err(mut err) => { |
| match token::TokenKind::Comma.similar_tokens() { |
| Some(tks) if tks.contains(&p.token.kind) => { |
| // If a similar token is found, then it may be a typo. We |
| // consider it as a comma, and continue parsing. |
| err.emit(); |
| p.bump(); |
| } |
| // Otherwise stop the parsing and return the error. |
| _ => return Err(err), |
| } |
| } |
| Ok(recovered) => { |
| assert!(recovered); |
| } |
| } |
| } |
| first = false; |
| if p.token == token::Eof { |
| break; |
| } // accept trailing commas |
| match p.token.ident() { |
| Some((ident, _)) if p.look_ahead(1, |t| *t == token::Eq) => { |
| named = true; |
| p.bump(); |
| p.expect(&token::Eq)?; |
| let e = p.parse_expr()?; |
| if let Some((prev, _)) = names.get(&ident.name) { |
| ecx.struct_span_err(e.span, &format!("duplicate argument named `{}`", ident)) |
| .span_label(args[*prev].expr.span, "previously here") |
| .span_label(e.span, "duplicate argument") |
| .emit(); |
| continue; |
| } |
| |
| // Resolve names into slots early. |
| // Since all the positional args are already seen at this point |
| // if the input is valid, we can simply append to the positional |
| // args. And remember the names. |
| let slot = args.len(); |
| names.insert(ident.name, (slot, ident.span)); |
| args.push(FormatArg { expr: e, named: true }); |
| } |
| _ => { |
| let e = p.parse_expr()?; |
| if named { |
| let mut err = ecx.struct_span_err( |
| e.span, |
| "positional arguments cannot follow named arguments", |
| ); |
| err.span_label(e.span, "positional arguments must be before named arguments"); |
| for pos in names.values() { |
| err.span_label(args[pos.0].expr.span, "named argument"); |
| } |
| err.emit(); |
| } |
| args.push(FormatArg { expr: e, named: false }); |
| } |
| } |
| } |
| Ok((fmtstr, args, names)) |
| } |
| |
| impl<'a, 'b> Context<'a, 'b> { |
| /// The number of arguments that were explicitly given. |
| fn num_args(&self) -> usize { |
| self.args.len() - self.num_captured_args |
| } |
| |
| fn resolve_name_inplace(&mut self, p: &mut parse::Piece<'_>) { |
| // NOTE: the `unwrap_or` branch is needed in case of invalid format |
| // arguments, e.g., `format_args!("{foo}")`. |
| let lookup = |
| |s: &str| self.names.get(&Symbol::intern(s)).unwrap_or(&(0, Span::default())).0; |
| |
| match *p { |
| parse::String(_) => {} |
| parse::NextArgument(ref mut arg) => { |
| if let parse::ArgumentNamed(s) = arg.position { |
| arg.position = parse::ArgumentIs(lookup(s)); |
| } |
| if let parse::CountIsName(s, _) = arg.format.width { |
| arg.format.width = parse::CountIsParam(lookup(s)); |
| } |
| if let parse::CountIsName(s, _) = arg.format.precision { |
| arg.format.precision = parse::CountIsParam(lookup(s)); |
| } |
| } |
| } |
| } |
| |
| /// Verifies one piece of a parse string, and remembers it if valid. |
| /// All errors are not emitted as fatal so we can continue giving errors |
| /// about this and possibly other format strings. |
| fn verify_piece(&mut self, p: &parse::Piece<'_>) { |
| match *p { |
| parse::String(..) => {} |
| parse::NextArgument(ref arg) => { |
| // width/precision first, if they have implicit positional |
| // parameters it makes more sense to consume them first. |
| self.verify_count( |
| arg.format.width, |
| &arg.format.width_span, |
| PositionalNamedArgType::Width, |
| ); |
| self.verify_count( |
| arg.format.precision, |
| &arg.format.precision_span, |
| PositionalNamedArgType::Precision, |
| ); |
| |
| let has_precision = arg.format.precision != Count::CountImplied; |
| let has_width = arg.format.width != Count::CountImplied; |
| |
| // argument second, if it's an implicit positional parameter |
| // it's written second, so it should come after width/precision. |
| let pos = match arg.position { |
| parse::ArgumentIs(i) => { |
| self.unused_names_lint.maybe_add_positional_named_arg( |
| i, |
| self.args.len(), |
| i, |
| PositionalNamedArgType::Arg, |
| self.curpiece, |
| Some(arg.position_span), |
| &self.names, |
| has_precision || has_width, |
| ); |
| |
| Exact(i) |
| } |
| parse::ArgumentImplicitlyIs(i) => { |
| self.unused_names_lint.maybe_add_positional_named_arg( |
| i, |
| self.args.len(), |
| i, |
| PositionalNamedArgType::Arg, |
| self.curpiece, |
| None, |
| &self.names, |
| has_precision || has_width, |
| ); |
| Exact(i) |
| } |
| parse::ArgumentNamed(s) => { |
| let symbol = Symbol::intern(s); |
| let span = arg.position_span; |
| Named(symbol, InnerSpan::new(span.start, span.end)) |
| } |
| }; |
| |
| let ty = Placeholder(match arg.format.ty { |
| "" => "Display", |
| "?" => "Debug", |
| "e" => "LowerExp", |
| "E" => "UpperExp", |
| "o" => "Octal", |
| "p" => "Pointer", |
| "b" => "Binary", |
| "x" => "LowerHex", |
| "X" => "UpperHex", |
| _ => { |
| let fmtsp = self.fmtsp; |
| let sp = arg |
| .format |
| .ty_span |
| .map(|sp| fmtsp.from_inner(InnerSpan::new(sp.start, sp.end))); |
| let mut err = self.ecx.struct_span_err( |
| sp.unwrap_or(fmtsp), |
| &format!("unknown format trait `{}`", arg.format.ty), |
| ); |
| err.note( |
| "the only appropriate formatting traits are:\n\ |
| - ``, which uses the `Display` trait\n\ |
| - `?`, which uses the `Debug` trait\n\ |
| - `e`, which uses the `LowerExp` trait\n\ |
| - `E`, which uses the `UpperExp` trait\n\ |
| - `o`, which uses the `Octal` trait\n\ |
| - `p`, which uses the `Pointer` trait\n\ |
| - `b`, which uses the `Binary` trait\n\ |
| - `x`, which uses the `LowerHex` trait\n\ |
| - `X`, which uses the `UpperHex` trait", |
| ); |
| if let Some(sp) = sp { |
| for (fmt, name) in &[ |
| ("", "Display"), |
| ("?", "Debug"), |
| ("e", "LowerExp"), |
| ("E", "UpperExp"), |
| ("o", "Octal"), |
| ("p", "Pointer"), |
| ("b", "Binary"), |
| ("x", "LowerHex"), |
| ("X", "UpperHex"), |
| ] { |
| // FIXME: rustfix (`run-rustfix`) fails to apply suggestions. |
| // > "Cannot replace slice of data that was already replaced" |
| err.tool_only_span_suggestion( |
| sp, |
| &format!("use the `{}` trait", name), |
| *fmt, |
| Applicability::MaybeIncorrect, |
| ); |
| } |
| } |
| err.emit(); |
| "<invalid>" |
| } |
| }); |
| self.verify_arg_type(pos, ty); |
| self.curpiece += 1; |
| } |
| } |
| } |
| |
| fn verify_count( |
| &mut self, |
| c: parse::Count<'_>, |
| inner_span: &Option<rustc_parse_format::InnerSpan>, |
| named_arg_type: PositionalNamedArgType, |
| ) { |
| match c { |
| parse::CountImplied | parse::CountIs(..) => {} |
| parse::CountIsParam(i) => { |
| self.unused_names_lint.maybe_add_positional_named_arg( |
| i, |
| self.args.len(), |
| i, |
| named_arg_type, |
| self.curpiece, |
| *inner_span, |
| &self.names, |
| true, |
| ); |
| self.verify_arg_type(Exact(i), Count); |
| } |
| parse::CountIsName(s, span) => { |
| self.verify_arg_type( |
| Named(Symbol::intern(s), InnerSpan::new(span.start, span.end)), |
| Count, |
| ); |
| } |
| } |
| } |
| |
| fn describe_num_args(&self) -> Cow<'_, str> { |
| match self.num_args() { |
| 0 => "no arguments were given".into(), |
| 1 => "there is 1 argument".into(), |
| x => format!("there are {} arguments", x).into(), |
| } |
| } |
| |
| /// Handle invalid references to positional arguments. Output different |
| /// errors for the case where all arguments are positional and for when |
| /// there are named arguments or numbered positional arguments in the |
| /// format string. |
| fn report_invalid_references(&self, numbered_position_args: bool) { |
| let mut e; |
| let sp = if !self.arg_spans.is_empty() { |
| // Point at the formatting arguments. |
| MultiSpan::from_spans(self.arg_spans.clone()) |
| } else { |
| MultiSpan::from_span(self.fmtsp) |
| }; |
| let refs = |
| self.invalid_refs.iter().map(|(r, pos)| (r.to_string(), self.arg_spans.get(*pos))); |
| |
| let mut zero_based_note = false; |
| |
| let count = self.pieces.len() |
| + self.arg_with_formatting.iter().filter(|fmt| fmt.precision_span.is_some()).count(); |
| if self.names.is_empty() && !numbered_position_args && count != self.num_args() { |
| e = self.ecx.struct_span_err( |
| sp, |
| &format!( |
| "{} positional argument{} in format string, but {}", |
| count, |
| pluralize!(count), |
| self.describe_num_args(), |
| ), |
| ); |
| for arg in &self.args { |
| // Point at the arguments that will be formatted. |
| e.span_label(arg.span, ""); |
| } |
| } else { |
| let (mut refs, spans): (Vec<_>, Vec<_>) = refs.unzip(); |
| // Avoid `invalid reference to positional arguments 7 and 7 (there is 1 argument)` |
| // for `println!("{7:7$}", 1);` |
| refs.sort(); |
| refs.dedup(); |
| let spans: Vec<_> = spans.into_iter().filter_map(|sp| sp.copied()).collect(); |
| let sp = if self.arg_spans.is_empty() || spans.is_empty() { |
| MultiSpan::from_span(self.fmtsp) |
| } else { |
| MultiSpan::from_spans(spans) |
| }; |
| let arg_list = if refs.len() == 1 { |
| format!("argument {}", refs[0]) |
| } else { |
| let reg = refs.pop().unwrap(); |
| format!("arguments {head} and {tail}", head = refs.join(", "), tail = reg) |
| }; |
| |
| e = self.ecx.struct_span_err( |
| sp, |
| &format!( |
| "invalid reference to positional {} ({})", |
| arg_list, |
| self.describe_num_args() |
| ), |
| ); |
| zero_based_note = true; |
| }; |
| |
| for fmt in &self.arg_with_formatting { |
| if let Some(span) = fmt.precision_span { |
| let span = self.fmtsp.from_inner(InnerSpan::new(span.start, span.end)); |
| match fmt.precision { |
| parse::CountIsParam(pos) if pos > self.num_args() => { |
| e.span_label( |
| span, |
| &format!( |
| "this precision flag expects an `usize` argument at position {}, \ |
| but {}", |
| pos, |
| self.describe_num_args(), |
| ), |
| ); |
| zero_based_note = true; |
| } |
| parse::CountIsParam(pos) => { |
| let count = self.pieces.len() |
| + self |
| .arg_with_formatting |
| .iter() |
| .filter(|fmt| fmt.precision_span.is_some()) |
| .count(); |
| e.span_label( |
| span, |
| &format!( |
| "this precision flag adds an extra required argument at position {}, \ |
| which is why there {} expected", |
| pos, |
| if count == 1 { |
| "is 1 argument".to_string() |
| } else { |
| format!("are {} arguments", count) |
| }, |
| ), |
| ); |
| if let Some(arg) = self.args.get(pos) { |
| e.span_label( |
| arg.span, |
| "this parameter corresponds to the precision flag", |
| ); |
| } |
| zero_based_note = true; |
| } |
| _ => {} |
| } |
| } |
| if let Some(span) = fmt.width_span { |
| let span = self.fmtsp.from_inner(InnerSpan::new(span.start, span.end)); |
| match fmt.width { |
| parse::CountIsParam(pos) if pos >= self.num_args() => { |
| e.span_label( |
| span, |
| &format!( |
| "this width flag expects an `usize` argument at position {}, \ |
| but {}", |
| pos, |
| self.describe_num_args(), |
| ), |
| ); |
| zero_based_note = true; |
| } |
| _ => {} |
| } |
| } |
| } |
| if zero_based_note { |
| e.note("positional arguments are zero-based"); |
| } |
| if !self.arg_with_formatting.is_empty() { |
| e.note( |
| "for information about formatting flags, visit \ |
| https://doc.rust-lang.org/std/fmt/index.html", |
| ); |
| } |
| |
| e.emit(); |
| } |
| |
| /// Actually verifies and tracks a given format placeholder |
| /// (a.k.a. argument). |
| fn verify_arg_type(&mut self, arg: Position, ty: ArgumentType) { |
| if let Exact(arg) = arg { |
| if arg >= self.num_args() { |
| self.invalid_refs.push((arg, self.curpiece)); |
| return; |
| } |
| } |
| |
| match arg { |
| Exact(arg) | Capture(arg) => { |
| match ty { |
| Placeholder(_) => { |
| // record every (position, type) combination only once |
| let seen_ty = &mut self.arg_unique_types[arg]; |
| let i = seen_ty.iter().position(|x| *x == ty).unwrap_or_else(|| { |
| let i = seen_ty.len(); |
| seen_ty.push(ty); |
| i |
| }); |
| self.arg_types[arg].push(i); |
| } |
| Count => { |
| if let Entry::Vacant(e) = self.count_positions.entry(arg) { |
| let i = self.count_positions_count; |
| e.insert(i); |
| self.count_args.push(arg); |
| self.count_positions_count += 1; |
| } |
| } |
| } |
| } |
| |
| Named(name, span) => { |
| match self.names.get(&name) { |
| Some(&idx) => { |
| // Treat as positional arg. |
| self.verify_arg_type(Capture(idx.0), ty) |
| } |
| None => { |
| // For the moment capturing variables from format strings expanded from macros is |
| // disabled (see RFC #2795) |
| if self.is_literal { |
| // Treat this name as a variable to capture from the surrounding scope |
| let idx = self.args.len(); |
| self.arg_types.push(Vec::new()); |
| self.arg_unique_types.push(Vec::new()); |
| let span = if self.is_literal { |
| self.fmtsp.from_inner(span) |
| } else { |
| self.fmtsp |
| }; |
| self.num_captured_args += 1; |
| self.args.push(self.ecx.expr_ident(span, Ident::new(name, span))); |
| self.names.insert(name, (idx, span)); |
| self.verify_arg_type(Capture(idx), ty) |
| } else { |
| let msg = format!("there is no argument named `{}`", name); |
| let sp = if self.is_literal { |
| self.fmtsp.from_inner(span) |
| } else { |
| self.fmtsp |
| }; |
| let mut err = self.ecx.struct_span_err(sp, &msg); |
| |
| err.note(&format!( |
| "did you intend to capture a variable `{}` from \ |
| the surrounding scope?", |
| name |
| )); |
| err.note( |
| "to avoid ambiguity, `format_args!` cannot capture variables \ |
| when the format string is expanded from a macro", |
| ); |
| |
| err.emit(); |
| } |
| } |
| } |
| } |
| } |
| } |
| |
| /// Builds the mapping between format placeholders and argument objects. |
| fn build_index_map(&mut self) { |
| // NOTE: Keep the ordering the same as `into_expr`'s expansion would do! |
| let args_len = self.args.len(); |
| self.arg_index_map.reserve(args_len); |
| |
| let mut sofar = 0usize; |
| |
| // Map the arguments |
| for i in 0..args_len { |
| let arg_types = &self.arg_types[i]; |
| let arg_offsets = arg_types.iter().map(|offset| sofar + *offset).collect::<Vec<_>>(); |
| self.arg_index_map.push(arg_offsets); |
| sofar += self.arg_unique_types[i].len(); |
| } |
| |
| // Record starting index for counts, which appear just after arguments |
| self.count_args_index_offset = sofar; |
| } |
| |
| fn rtpath(ecx: &ExtCtxt<'_>, s: Symbol) -> Vec<Ident> { |
| ecx.std_path(&[sym::fmt, sym::rt, sym::v1, s]) |
| } |
| |
| fn build_count(&self, c: parse::Count<'_>) -> P<ast::Expr> { |
| let sp = self.macsp; |
| let count = |c, arg| { |
| let mut path = Context::rtpath(self.ecx, sym::Count); |
| path.push(Ident::new(c, sp)); |
| match arg { |
| Some(arg) => self.ecx.expr_call_global(sp, path, vec![arg]), |
| None => self.ecx.expr_path(self.ecx.path_global(sp, path)), |
| } |
| }; |
| match c { |
| parse::CountIs(i) => count(sym::Is, Some(self.ecx.expr_usize(sp, i))), |
| parse::CountIsParam(i) => { |
| // This needs mapping too, as `i` is referring to a macro |
| // argument. If `i` is not found in `count_positions` then |
| // the error had already been emitted elsewhere. |
| let i = self.count_positions.get(&i).cloned().unwrap_or(0) |
| + self.count_args_index_offset; |
| count(sym::Param, Some(self.ecx.expr_usize(sp, i))) |
| } |
| parse::CountImplied => count(sym::Implied, None), |
| // should never be the case, names are already resolved |
| parse::CountIsName(..) => panic!("should never happen"), |
| } |
| } |
| |
| /// Build a literal expression from the accumulated string literals |
| fn build_literal_string(&mut self) -> P<ast::Expr> { |
| let sp = self.fmtsp; |
| let s = Symbol::intern(&self.literal); |
| self.literal.clear(); |
| self.ecx.expr_str(sp, s) |
| } |
| |
| /// Builds a static `rt::Argument` from a `parse::Piece` or append |
| /// to the `literal` string. |
| fn build_piece( |
| &mut self, |
| piece: &parse::Piece<'a>, |
| arg_index_consumed: &mut Vec<usize>, |
| ) -> Option<P<ast::Expr>> { |
| let sp = self.macsp; |
| match *piece { |
| parse::String(s) => { |
| self.literal.push_str(s); |
| None |
| } |
| parse::NextArgument(ref arg) => { |
| // Build the position |
| let pos = { |
| match arg.position { |
| parse::ArgumentIs(i, ..) | parse::ArgumentImplicitlyIs(i) => { |
| // Map to index in final generated argument array |
| // in case of multiple types specified |
| let arg_idx = match arg_index_consumed.get_mut(i) { |
| None => 0, // error already emitted elsewhere |
| Some(offset) => { |
| let idx_map = &self.arg_index_map[i]; |
| // unwrap_or branch: error already emitted elsewhere |
| let arg_idx = *idx_map.get(*offset).unwrap_or(&0); |
| *offset += 1; |
| arg_idx |
| } |
| }; |
| self.ecx.expr_usize(sp, arg_idx) |
| } |
| |
| // should never be the case, because names are already |
| // resolved. |
| parse::ArgumentNamed(..) => panic!("should never happen"), |
| } |
| }; |
| |
| let simple_arg = parse::Argument { |
| position: { |
| // We don't have ArgumentNext any more, so we have to |
| // track the current argument ourselves. |
| let i = self.curarg; |
| self.curarg += 1; |
| parse::ArgumentIs(i) |
| }, |
| position_span: arg.position_span, |
| format: parse::FormatSpec { |
| fill: arg.format.fill, |
| align: parse::AlignUnknown, |
| flags: 0, |
| precision: parse::CountImplied, |
| precision_span: None, |
| width: parse::CountImplied, |
| width_span: None, |
| ty: arg.format.ty, |
| ty_span: arg.format.ty_span, |
| }, |
| }; |
| |
| let fill = arg.format.fill.unwrap_or(' '); |
| |
| let pos_simple = arg.position.index() == simple_arg.position.index(); |
| |
| if arg.format.precision_span.is_some() || arg.format.width_span.is_some() { |
| self.arg_with_formatting.push(arg.format); |
| } |
| if !pos_simple || arg.format != simple_arg.format || fill != ' ' { |
| self.all_pieces_simple = false; |
| } |
| |
| // Build the format |
| let fill = self.ecx.expr_lit(sp, ast::LitKind::Char(fill)); |
| let align = |name| { |
| let mut p = Context::rtpath(self.ecx, sym::Alignment); |
| p.push(Ident::new(name, sp)); |
| self.ecx.path_global(sp, p) |
| }; |
| let align = match arg.format.align { |
| parse::AlignLeft => align(sym::Left), |
| parse::AlignRight => align(sym::Right), |
| parse::AlignCenter => align(sym::Center), |
| parse::AlignUnknown => align(sym::Unknown), |
| }; |
| let align = self.ecx.expr_path(align); |
| let flags = self.ecx.expr_u32(sp, arg.format.flags); |
| let prec = self.build_count(arg.format.precision); |
| let width = self.build_count(arg.format.width); |
| let path = self.ecx.path_global(sp, Context::rtpath(self.ecx, sym::FormatSpec)); |
| let fmt = self.ecx.expr_struct( |
| sp, |
| path, |
| vec![ |
| self.ecx.field_imm(sp, Ident::new(sym::fill, sp), fill), |
| self.ecx.field_imm(sp, Ident::new(sym::align, sp), align), |
| self.ecx.field_imm(sp, Ident::new(sym::flags, sp), flags), |
| self.ecx.field_imm(sp, Ident::new(sym::precision, sp), prec), |
| self.ecx.field_imm(sp, Ident::new(sym::width, sp), width), |
| ], |
| ); |
| |
| let path = self.ecx.path_global(sp, Context::rtpath(self.ecx, sym::Argument)); |
| Some(self.ecx.expr_struct( |
| sp, |
| path, |
| vec![ |
| self.ecx.field_imm(sp, Ident::new(sym::position, sp), pos), |
| self.ecx.field_imm(sp, Ident::new(sym::format, sp), fmt), |
| ], |
| )) |
| } |
| } |
| } |
| |
| /// Actually builds the expression which the format_args! block will be |
| /// expanded to. |
| fn into_expr(self) -> P<ast::Expr> { |
| let mut original_args = self.args; |
| let mut fmt_args = Vec::with_capacity( |
| self.arg_unique_types.iter().map(|v| v.len()).sum::<usize>() + self.count_args.len(), |
| ); |
| |
| // First, build up the static array which will become our precompiled |
| // format "string" |
| let pieces = self.ecx.expr_array_ref(self.fmtsp, self.str_pieces); |
| |
| // We need to construct a &[ArgumentV1] to pass into the fmt::Arguments |
| // constructor. In general the expressions in this slice might be |
| // permuted from their order in original_args (such as in the case of |
| // "{1} {0}"), or may have multiple entries referring to the same |
| // element of original_args ("{0} {0}"). |
| // |
| // The following vector has one item per element of our output slice, |
| // identifying the index of which element of original_args it's passing, |
| // and that argument's type. |
| let mut fmt_arg_index_and_ty = SmallVec::<[(usize, &ArgumentType); 8]>::new(); |
| for (i, unique_types) in self.arg_unique_types.iter().enumerate() { |
| fmt_arg_index_and_ty.extend(unique_types.iter().map(|ty| (i, ty))); |
| } |
| fmt_arg_index_and_ty.extend(self.count_args.iter().map(|&i| (i, &Count))); |
| |
| // Figure out whether there are permuted or repeated elements. If not, |
| // we can generate simpler code. |
| // |
| // The sequence has no indices out of order or repeated if: for every |
| // adjacent pair of elements, the first one's index is less than the |
| // second one's index. |
| let nicely_ordered = |
| fmt_arg_index_and_ty.array_windows().all(|[(i, _i_ty), (j, _j_ty)]| i < j); |
| |
| // We want to emit: |
| // |
| // [ArgumentV1::new(&$arg0, …), ArgumentV1::new(&$arg1, …), …] |
| // |
| // However, it's only legal to do so if $arg0, $arg1, … were written in |
| // exactly that order by the programmer. When arguments are permuted, we |
| // want them evaluated in the order written by the programmer, not in |
| // the order provided to fmt::Arguments. When arguments are repeated, we |
| // want the expression evaluated only once. |
| // |
| // Further, if any arg _after the first one_ contains a yield point such |
| // as `await` or `yield`, the above short form is inconvenient for the |
| // caller because it would keep a temporary of type ArgumentV1 alive |
| // across the yield point. ArgumentV1 can't implement Send since it |
| // holds a type-erased arbitrary type. |
| // |
| // Thus in the not nicely ordered case, and in the yielding case, we |
| // emit the following instead: |
| // |
| // match (&$arg0, &$arg1, …) { |
| // args => [ArgumentV1::new(args.$i, …), ArgumentV1::new(args.$j, …), …] |
| // } |
| // |
| // for the sequence of indices $i, $j, … governed by fmt_arg_index_and_ty. |
| // This more verbose representation ensures that all arguments are |
| // evaluated a single time each, in the order written by the programmer, |
| // and that the surrounding future/generator (if any) is Send whenever |
| // possible. |
| let no_need_for_match = |
| nicely_ordered && !original_args.iter().skip(1).any(|e| may_contain_yield_point(e)); |
| |
| for (arg_index, arg_ty) in fmt_arg_index_and_ty { |
| let e = &mut original_args[arg_index]; |
| let span = e.span; |
| let arg = if no_need_for_match { |
| let expansion_span = e.span.with_ctxt(self.macsp.ctxt()); |
| // The indices are strictly ordered so e has not been taken yet. |
| self.ecx.expr_addr_of(expansion_span, P(e.take())) |
| } else { |
| let def_site = self.ecx.with_def_site_ctxt(span); |
| let args_tuple = self.ecx.expr_ident(def_site, Ident::new(sym::args, def_site)); |
| let member = Ident::new(sym::integer(arg_index), def_site); |
| self.ecx.expr(def_site, ast::ExprKind::Field(args_tuple, member)) |
| }; |
| fmt_args.push(Context::format_arg(self.ecx, self.macsp, span, arg_ty, arg)); |
| } |
| |
| let args_array = self.ecx.expr_array(self.macsp, fmt_args); |
| let args_slice = self.ecx.expr_addr_of( |
| self.macsp, |
| if no_need_for_match { |
| args_array |
| } else { |
| // In the !no_need_for_match case, none of the exprs were moved |
| // away in the previous loop. |
| // |
| // This uses the arg span for `&arg` so that borrowck errors |
| // point to the specific expression passed to the macro (the |
| // span is otherwise unavailable in the MIR used by borrowck). |
| let heads = original_args |
| .into_iter() |
| .map(|e| self.ecx.expr_addr_of(e.span.with_ctxt(self.macsp.ctxt()), e)) |
| .collect(); |
| |
| let pat = self.ecx.pat_ident(self.macsp, Ident::new(sym::args, self.macsp)); |
| let arm = self.ecx.arm(self.macsp, pat, args_array); |
| let head = self.ecx.expr(self.macsp, ast::ExprKind::Tup(heads)); |
| self.ecx.expr_match(self.macsp, head, vec![arm]) |
| }, |
| ); |
| |
| // Now create the fmt::Arguments struct with all our locals we created. |
| let (fn_name, fn_args) = if self.all_pieces_simple { |
| ("new_v1", vec![pieces, args_slice]) |
| } else { |
| // Build up the static array which will store our precompiled |
| // nonstandard placeholders, if there are any. |
| let fmt = self.ecx.expr_array_ref(self.macsp, self.pieces); |
| |
| let path = self.ecx.std_path(&[sym::fmt, sym::UnsafeArg, sym::new]); |
| let unsafe_arg = self.ecx.expr_call_global(self.macsp, path, Vec::new()); |
| let unsafe_expr = self.ecx.expr_block(P(ast::Block { |
| stmts: vec![self.ecx.stmt_expr(unsafe_arg)], |
| id: ast::DUMMY_NODE_ID, |
| rules: BlockCheckMode::Unsafe(UnsafeSource::CompilerGenerated), |
| span: self.macsp, |
| tokens: None, |
| could_be_bare_literal: false, |
| })); |
| |
| ("new_v1_formatted", vec![pieces, args_slice, fmt, unsafe_expr]) |
| }; |
| |
| let path = self.ecx.std_path(&[sym::fmt, sym::Arguments, Symbol::intern(fn_name)]); |
| self.ecx.expr_call_global(self.macsp, path, fn_args) |
| } |
| |
| fn format_arg( |
| ecx: &ExtCtxt<'_>, |
| macsp: Span, |
| mut sp: Span, |
| ty: &ArgumentType, |
| arg: P<ast::Expr>, |
| ) -> P<ast::Expr> { |
| sp = ecx.with_def_site_ctxt(sp); |
| let trait_ = match *ty { |
| Placeholder(trait_) if trait_ == "<invalid>" => return DummyResult::raw_expr(sp, true), |
| Placeholder(trait_) => trait_, |
| Count => { |
| let path = ecx.std_path(&[sym::fmt, sym::ArgumentV1, sym::from_usize]); |
| return ecx.expr_call_global(macsp, path, vec![arg]); |
| } |
| }; |
| let new_fn_name = match trait_ { |
| "Display" => "new_display", |
| "Debug" => "new_debug", |
| "LowerExp" => "new_lower_exp", |
| "UpperExp" => "new_upper_exp", |
| "Octal" => "new_octal", |
| "Pointer" => "new_pointer", |
| "Binary" => "new_binary", |
| "LowerHex" => "new_lower_hex", |
| "UpperHex" => "new_upper_hex", |
| _ => unreachable!(), |
| }; |
| |
| let path = ecx.std_path(&[sym::fmt, sym::ArgumentV1, Symbol::intern(new_fn_name)]); |
| ecx.expr_call_global(sp, path, vec![arg]) |
| } |
| } |
| |
| fn expand_format_args_impl<'cx>( |
| ecx: &'cx mut ExtCtxt<'_>, |
| mut sp: Span, |
| tts: TokenStream, |
| nl: bool, |
| ) -> Box<dyn base::MacResult + 'cx> { |
| sp = ecx.with_def_site_ctxt(sp); |
| match parse_args(ecx, sp, tts) { |
| Ok((efmt, args, names)) => { |
| MacEager::expr(expand_preparsed_format_args(ecx, sp, efmt, args, names, nl)) |
| } |
| Err(mut err) => { |
| err.emit(); |
| DummyResult::any(sp) |
| } |
| } |
| } |
| |
| pub fn expand_format_args<'cx>( |
| ecx: &'cx mut ExtCtxt<'_>, |
| sp: Span, |
| tts: TokenStream, |
| ) -> Box<dyn base::MacResult + 'cx> { |
| expand_format_args_impl(ecx, sp, tts, false) |
| } |
| |
| pub fn expand_format_args_nl<'cx>( |
| ecx: &'cx mut ExtCtxt<'_>, |
| sp: Span, |
| tts: TokenStream, |
| ) -> Box<dyn base::MacResult + 'cx> { |
| expand_format_args_impl(ecx, sp, tts, true) |
| } |
| |
| fn create_lints_for_named_arguments_used_positionally(cx: &mut Context<'_, '_>) { |
| for named_arg in &cx.unused_names_lint.positional_named_args { |
| let (position_sp_to_replace, position_sp_for_msg) = named_arg.get_positional_arg_spans(cx); |
| |
| let msg = format!("named argument `{}` is not used by name", named_arg.replacement); |
| |
| cx.ecx.buffered_early_lint.push(BufferedEarlyLint { |
| span: MultiSpan::from_span(named_arg.positional_named_arg_span), |
| msg: msg.clone(), |
| node_id: ast::CRATE_NODE_ID, |
| lint_id: LintId::of(&NAMED_ARGUMENTS_USED_POSITIONALLY), |
| diagnostic: BuiltinLintDiagnostics::NamedArgumentUsedPositionally { |
| position_sp_to_replace, |
| position_sp_for_msg, |
| named_arg_sp: named_arg.positional_named_arg_span, |
| named_arg_name: named_arg.replacement.to_string(), |
| is_formatting_arg: named_arg.ty != PositionalNamedArgType::Arg, |
| }, |
| }); |
| } |
| } |
| |
| /// Take the various parts of `format_args!(efmt, args..., name=names...)` |
| /// and construct the appropriate formatting expression. |
| pub fn expand_preparsed_format_args( |
| ecx: &mut ExtCtxt<'_>, |
| sp: Span, |
| efmt: P<ast::Expr>, |
| args: Vec<FormatArg>, |
| names: FxHashMap<Symbol, (usize, Span)>, |
| append_newline: bool, |
| ) -> P<ast::Expr> { |
| // NOTE: this verbose way of initializing `Vec<Vec<ArgumentType>>` is because |
| // `ArgumentType` does not derive `Clone`. |
| let arg_types: Vec<_> = (0..args.len()).map(|_| Vec::new()).collect(); |
| let arg_unique_types: Vec<_> = (0..args.len()).map(|_| Vec::new()).collect(); |
| |
| let mut macsp = ecx.call_site(); |
| macsp = ecx.with_def_site_ctxt(macsp); |
| |
| let msg = "format argument must be a string literal"; |
| let fmt_sp = efmt.span; |
| let efmt_kind_is_lit: bool = matches!(efmt.kind, ast::ExprKind::Lit(_)); |
| let (fmt_str, fmt_style, fmt_span) = match expr_to_spanned_string(ecx, efmt, msg) { |
| Ok(mut fmt) if append_newline => { |
| fmt.0 = Symbol::intern(&format!("{}\n", fmt.0)); |
| fmt |
| } |
| Ok(fmt) => fmt, |
| Err(err) => { |
| if let Some((mut err, suggested)) = err { |
| let sugg_fmt = match args.len() { |
| 0 => "{}".to_string(), |
| _ => format!("{}{{}}", "{} ".repeat(args.len())), |
| }; |
| if !suggested { |
| err.span_suggestion( |
| fmt_sp.shrink_to_lo(), |
| "you might be missing a string literal to format with", |
| format!("\"{}\", ", sugg_fmt), |
| Applicability::MaybeIncorrect, |
| ); |
| } |
| err.emit(); |
| } |
| return DummyResult::raw_expr(sp, true); |
| } |
| }; |
| |
| let str_style = match fmt_style { |
| ast::StrStyle::Cooked => None, |
| ast::StrStyle::Raw(raw) => Some(raw as usize), |
| }; |
| |
| let fmt_str = fmt_str.as_str(); // for the suggestions below |
| let fmt_snippet = ecx.source_map().span_to_snippet(fmt_sp).ok(); |
| let mut parser = parse::Parser::new( |
| fmt_str, |
| str_style, |
| fmt_snippet, |
| append_newline, |
| parse::ParseMode::Format, |
| ); |
| |
| let mut unverified_pieces = Vec::new(); |
| while let Some(piece) = parser.next() { |
| if !parser.errors.is_empty() { |
| break; |
| } else { |
| unverified_pieces.push(piece); |
| } |
| } |
| |
| if !parser.errors.is_empty() { |
| let err = parser.errors.remove(0); |
| let sp = if efmt_kind_is_lit { |
| fmt_span.from_inner(InnerSpan::new(err.span.start, err.span.end)) |
| } else { |
| // The format string could be another macro invocation, e.g.: |
| // format!(concat!("abc", "{}"), 4); |
| // However, `err.span` is an inner span relative to the *result* of |
| // the macro invocation, which is why we would get a nonsensical |
| // result calling `fmt_span.from_inner(err.span)` as above, and |
| // might even end up inside a multibyte character (issue #86085). |
| // Therefore, we conservatively report the error for the entire |
| // argument span here. |
| fmt_span |
| }; |
| let mut e = ecx.struct_span_err(sp, &format!("invalid format string: {}", err.description)); |
| e.span_label(sp, err.label + " in format string"); |
| if let Some(note) = err.note { |
| e.note(¬e); |
| } |
| if let Some((label, span)) = err.secondary_label { |
| if efmt_kind_is_lit { |
| e.span_label(fmt_span.from_inner(InnerSpan::new(span.start, span.end)), label); |
| } |
| } |
| if err.should_be_replaced_with_positional_argument { |
| let captured_arg_span = |
| fmt_span.from_inner(InnerSpan::new(err.span.start, err.span.end)); |
| let positional_args = args.iter().filter(|arg| !arg.named).collect::<Vec<_>>(); |
| if let Ok(arg) = ecx.source_map().span_to_snippet(captured_arg_span) { |
| let span = match positional_args.last() { |
| Some(arg) => arg.expr.span, |
| None => fmt_sp, |
| }; |
| e.multipart_suggestion_verbose( |
| "consider using a positional formatting argument instead", |
| vec![ |
| (captured_arg_span, positional_args.len().to_string()), |
| (span.shrink_to_hi(), format!(", {}", arg)), |
| ], |
| Applicability::MachineApplicable, |
| ); |
| } |
| } |
| e.emit(); |
| return DummyResult::raw_expr(sp, true); |
| } |
| |
| let arg_spans = parser |
| .arg_places |
| .iter() |
| .map(|span| fmt_span.from_inner(InnerSpan::new(span.start, span.end))) |
| .collect(); |
| |
| let named_pos: FxHashSet<usize> = names.values().cloned().map(|(i, _)| i).collect(); |
| |
| let mut cx = Context { |
| ecx, |
| args: args.into_iter().map(|arg| arg.expr).collect(), |
| num_captured_args: 0, |
| arg_types, |
| arg_unique_types, |
| names, |
| curarg: 0, |
| curpiece: 0, |
| arg_index_map: Vec::new(), |
| count_args: Vec::new(), |
| count_positions: FxHashMap::default(), |
| count_positions_count: 0, |
| count_args_index_offset: 0, |
| literal: String::new(), |
| pieces: Vec::with_capacity(unverified_pieces.len()), |
| str_pieces: Vec::with_capacity(unverified_pieces.len()), |
| all_pieces_simple: true, |
| macsp, |
| fmtsp: fmt_span, |
| invalid_refs: Vec::new(), |
| arg_spans, |
| arg_with_formatting: Vec::new(), |
| is_literal: parser.is_literal, |
| unused_names_lint: PositionalNamedArgsLint { positional_named_args: vec![] }, |
| }; |
| |
| // This needs to happen *after* the Parser has consumed all pieces to create all the spans |
| let pieces = unverified_pieces |
| .into_iter() |
| .map(|mut piece| { |
| cx.verify_piece(&piece); |
| cx.resolve_name_inplace(&mut piece); |
| piece |
| }) |
| .collect::<Vec<_>>(); |
| |
| let numbered_position_args = pieces.iter().any(|arg: &parse::Piece<'_>| match *arg { |
| parse::String(_) => false, |
| parse::NextArgument(arg) => matches!(arg.position, parse::Position::ArgumentIs(..)), |
| }); |
| |
| cx.build_index_map(); |
| |
| let mut arg_index_consumed = vec![0usize; cx.arg_index_map.len()]; |
| |
| for piece in pieces { |
| if let Some(piece) = cx.build_piece(&piece, &mut arg_index_consumed) { |
| let s = cx.build_literal_string(); |
| cx.str_pieces.push(s); |
| cx.pieces.push(piece); |
| } |
| } |
| |
| if !cx.literal.is_empty() { |
| let s = cx.build_literal_string(); |
| cx.str_pieces.push(s); |
| } |
| |
| if !cx.invalid_refs.is_empty() { |
| cx.report_invalid_references(numbered_position_args); |
| } |
| |
| // Make sure that all arguments were used and all arguments have types. |
| let errs = cx |
| .arg_types |
| .iter() |
| .enumerate() |
| .filter(|(i, ty)| ty.is_empty() && !cx.count_positions.contains_key(&i)) |
| .map(|(i, _)| { |
| let msg = if named_pos.contains(&i) { |
| // named argument |
| "named argument never used" |
| } else { |
| // positional argument |
| "argument never used" |
| }; |
| (cx.args[i].span, msg) |
| }) |
| .collect::<Vec<_>>(); |
| |
| let errs_len = errs.len(); |
| if !errs.is_empty() { |
| let args_used = cx.arg_types.len() - errs_len; |
| let args_unused = errs_len; |
| |
| let mut diag = { |
| if let [(sp, msg)] = &errs[..] { |
| let mut diag = cx.ecx.struct_span_err(*sp, *msg); |
| diag.span_label(*sp, *msg); |
| diag |
| } else { |
| let mut diag = cx.ecx.struct_span_err( |
| errs.iter().map(|&(sp, _)| sp).collect::<Vec<Span>>(), |
| "multiple unused formatting arguments", |
| ); |
| diag.span_label(cx.fmtsp, "multiple missing formatting specifiers"); |
| for (sp, msg) in errs { |
| diag.span_label(sp, msg); |
| } |
| diag |
| } |
| }; |
| |
| // Used to ensure we only report translations for *one* kind of foreign format. |
| let mut found_foreign = false; |
| // Decide if we want to look for foreign formatting directives. |
| if args_used < args_unused { |
| use super::format_foreign as foreign; |
| |
| // The set of foreign substitutions we've explained. This prevents spamming the user |
| // with `%d should be written as {}` over and over again. |
| let mut explained = FxHashSet::default(); |
| |
| macro_rules! check_foreign { |
| ($kind:ident) => {{ |
| let mut show_doc_note = false; |
| |
| let mut suggestions = vec![]; |
| // account for `"` and account for raw strings `r#` |
| let padding = str_style.map(|i| i + 2).unwrap_or(1); |
| for sub in foreign::$kind::iter_subs(fmt_str, padding) { |
| let (trn, success) = match sub.translate() { |
| Ok(trn) => (trn, true), |
| Err(Some(msg)) => (msg, false), |
| |
| // If it has no translation, don't call it out specifically. |
| _ => continue, |
| }; |
| |
| let pos = sub.position(); |
| let sub = String::from(sub.as_str()); |
| if explained.contains(&sub) { |
| continue; |
| } |
| explained.insert(sub.clone()); |
| |
| if !found_foreign { |
| found_foreign = true; |
| show_doc_note = true; |
| } |
| |
| if let Some(inner_sp) = pos { |
| let sp = fmt_sp.from_inner(inner_sp); |
| |
| if success { |
| suggestions.push((sp, trn)); |
| } else { |
| diag.span_note( |
| sp, |
| &format!("format specifiers use curly braces, and {}", trn), |
| ); |
| } |
| } else { |
| if success { |
| diag.help(&format!("`{}` should be written as `{}`", sub, trn)); |
| } else { |
| diag.note(&format!( |
| "`{}` should use curly braces, and {}", |
| sub, trn |
| )); |
| } |
| } |
| } |
| |
| if show_doc_note { |
| diag.note(concat!( |
| stringify!($kind), |
| " formatting not supported; see the documentation for `std::fmt`", |
| )); |
| } |
| if suggestions.len() > 0 { |
| diag.multipart_suggestion( |
| "format specifiers use curly braces", |
| suggestions, |
| Applicability::MachineApplicable, |
| ); |
| } |
| }}; |
| } |
| |
| check_foreign!(printf); |
| if !found_foreign { |
| check_foreign!(shell); |
| } |
| } |
| if !found_foreign && errs_len == 1 { |
| diag.span_label(cx.fmtsp, "formatting specifier missing"); |
| } |
| |
| diag.emit(); |
| } else if cx.invalid_refs.is_empty() && cx.ecx.sess.err_count() == 0 { |
| // Only check for unused named argument names if there are no other errors to avoid causing |
| // too much noise in output errors, such as when a named argument is entirely unused. |
| create_lints_for_named_arguments_used_positionally(&mut cx); |
| } |
| |
| cx.into_expr() |
| } |
| |
| fn may_contain_yield_point(e: &ast::Expr) -> bool { |
| struct MayContainYieldPoint(bool); |
| |
| impl Visitor<'_> for MayContainYieldPoint { |
| fn visit_expr(&mut self, e: &ast::Expr) { |
| if let ast::ExprKind::Await(_) | ast::ExprKind::Yield(_) = e.kind { |
| self.0 = true; |
| } else { |
| visit::walk_expr(self, e); |
| } |
| } |
| |
| fn visit_mac_call(&mut self, _: &ast::MacCall) { |
| self.0 = true; |
| } |
| |
| fn visit_attribute(&mut self, _: &ast::Attribute) { |
| // Conservatively assume this may be a proc macro attribute in |
| // expression position. |
| self.0 = true; |
| } |
| |
| fn visit_item(&mut self, _: &ast::Item) { |
| // Do not recurse into nested items. |
| } |
| } |
| |
| let mut visitor = MayContainYieldPoint(false); |
| visitor.visit_expr(e); |
| visitor.0 |
| } |
