| use ArgumentType::*; |
| use Position::*; |
| |
| use fmt_macros as parse; |
| |
| use errors::DiagnosticBuilder; |
| use errors::Applicability; |
| use errors::pluralize; |
| |
| use syntax::ast; |
| use syntax_expand::base::{self, *}; |
| use syntax::token; |
| use syntax::ptr::P; |
| use syntax::symbol::{Symbol, sym}; |
| use syntax::tokenstream::TokenStream; |
| use syntax_pos::{MultiSpan, Span}; |
| |
| use rustc_data_structures::fx::{FxHashMap, FxHashSet}; |
| use std::borrow::Cow; |
| use std::collections::hash_map::Entry; |
| |
| #[derive(PartialEq)] |
| enum ArgumentType { |
| Placeholder(&'static str), |
| Count, |
| } |
| |
| enum Position { |
| Exact(usize), |
| Named(Symbol), |
| } |
| |
| 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>>, |
| /// 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>, |
| |
| /// 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![Exact(0), Exact(5), Exact(3)]` |
| count_args: Vec<Position>, |
| /// 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 formatting string is a literal or it comes from a macro. |
| is_literal: 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, |
| ) -> Result<(P<ast::Expr>, Vec<P<ast::Expr>>, FxHashMap<Symbol, usize>), DiagnosticBuilder<'a>> { |
| let mut args = Vec::<P<ast::Expr>>::new(); |
| let mut names = FxHashMap::<Symbol, usize>::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 fmtstr = p.parse_expr()?; |
| let mut first = true; |
| let mut named = false; |
| |
| while p.token != token::Eof { |
| if !p.eat(&token::Comma) { |
| if first { |
| // After `format!(""` we always expect *only* a comma... |
| let mut err = ecx.struct_span_err(p.token.span, "expected token: `,`"); |
| err.span_label(p.token.span, "expected `,`"); |
| p.maybe_annotate_with_ascription(&mut err, false); |
| return Err(err); |
| } else { |
| // ...after that delegate to `expect` to also include the other expected tokens. |
| return Err(p.expect(&token::Comma).err().unwrap()); |
| } |
| } |
| first = false; |
| if p.token == token::Eof { |
| break; |
| } // accept trailing commas |
| if p.token.is_ident() && p.look_ahead(1, |t| *t == token::Eq) { |
| named = true; |
| let name = if let token::Ident(name, _) = p.token.kind { |
| p.bump(); |
| name |
| } else { |
| unreachable!(); |
| }; |
| |
| p.expect(&token::Eq)?; |
| let e = p.parse_expr()?; |
| if let Some(prev) = names.get(&name) { |
| ecx.struct_span_err(e.span, &format!("duplicate argument named `{}`", name)) |
| .span_label(args[*prev].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(name, slot); |
| args.push(e); |
| } else { |
| 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 { |
| err.span_label(args[*pos].span, "named argument"); |
| } |
| err.emit(); |
| } |
| args.push(e); |
| } |
| } |
| Ok((fmtstr, args, names)) |
| } |
| |
| impl<'a, 'b> Context<'a, 'b> { |
| fn resolve_name_inplace(&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: Symbol| *self.names.get(&s).unwrap_or(&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); |
| self.verify_count(arg.format.precision); |
| |
| // 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) | parse::ArgumentImplicitlyIs(i) => Exact(i), |
| parse::ArgumentNamed(s) => Named(s), |
| }; |
| |
| 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(sp)); |
| 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"), |
| ] { |
| err.tool_only_span_suggestion( |
| sp, |
| &format!("use the `{}` trait", name), |
| fmt.to_string(), |
| Applicability::MaybeIncorrect, |
| ); |
| } |
| } |
| err.emit(); |
| "<invalid>" |
| } |
| }); |
| self.verify_arg_type(pos, ty); |
| self.curpiece += 1; |
| } |
| } |
| } |
| |
| fn verify_count(&mut self, c: parse::Count) { |
| match c { |
| parse::CountImplied | |
| parse::CountIs(..) => {} |
| parse::CountIsParam(i) => { |
| self.verify_arg_type(Exact(i), Count); |
| } |
| parse::CountIsName(s) => { |
| self.verify_arg_type(Named(s), Count); |
| } |
| } |
| } |
| |
| fn describe_num_args(&self) -> Cow<'_, str> { |
| match self.args.len() { |
| 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.is_literal { // 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.args.len() { |
| 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 (arg_list, mut sp) = if refs.len() == 1 { |
| let spans: Vec<_> = spans.into_iter().filter_map(|sp| sp.map(|sp| *sp)).collect(); |
| ( |
| format!("argument {}", refs[0]), |
| if spans.is_empty() { |
| MultiSpan::from_span(self.fmtsp) |
| } else { |
| MultiSpan::from_spans(spans) |
| }, |
| ) |
| } else { |
| let pos = MultiSpan::from_spans(spans.into_iter().map(|s| *s.unwrap()).collect()); |
| let reg = refs.pop().unwrap(); |
| ( |
| format!( |
| "arguments {head} and {tail}", |
| head = refs.join(", "), |
| tail = reg, |
| ), |
| pos, |
| ) |
| }; |
| if !self.is_literal { |
| sp = MultiSpan::from_span(self.fmtsp); |
| } |
| |
| 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(span); |
| match fmt.precision { |
| parse::CountIsParam(pos) if pos > self.args.len() => { |
| 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(span); |
| match fmt.width { |
| parse::CountIsParam(pos) if pos > self.args.len() => { |
| 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) { |
| match arg { |
| Exact(arg) => { |
| if self.args.len() <= arg { |
| self.invalid_refs.push((arg, self.curpiece)); |
| return; |
| } |
| match ty { |
| Placeholder(_) => { |
| // record every (position, type) combination only once |
| let ref mut seen_ty = 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(Exact(arg)); |
| self.count_positions_count += 1; |
| } |
| } |
| } |
| } |
| |
| Named(name) => { |
| match self.names.get(&name) { |
| Some(&idx) => { |
| // Treat as positional arg. |
| self.verify_arg_type(Exact(idx), ty) |
| } |
| None => { |
| let msg = format!("there is no argument named `{}`", name); |
| let sp = if self.is_literal { |
| *self.arg_spans.get(self.curpiece).unwrap_or(&self.fmtsp) |
| } else { |
| self.fmtsp |
| }; |
| let mut err = self.ecx.struct_span_err(sp, &msg[..]); |
| 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 ref 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: &str) -> Vec<ast::Ident> { |
| ecx.std_path(&[sym::fmt, sym::rt, sym::v1, Symbol::intern(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, "Count"); |
| path.push(self.ecx.ident_of(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("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("Param", Some(self.ecx.expr_usize(sp, i))) |
| } |
| parse::CountImplied => count("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 = { |
| let pos = |c, arg| { |
| let mut path = Context::rtpath(self.ecx, "Position"); |
| path.push(self.ecx.ident_of(c, sp)); |
| match arg { |
| Some(i) => { |
| let arg = self.ecx.expr_usize(sp, i); |
| self.ecx.expr_call_global(sp, path, vec![arg]) |
| } |
| None => self.ecx.expr_path(self.ecx.path_global(sp, path)), |
| } |
| }; |
| 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 ref 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 |
| } |
| }; |
| pos("At", Some(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) |
| }, |
| 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, "Alignment"); |
| p.push(self.ecx.ident_of(name, sp)); |
| self.ecx.path_global(sp, p) |
| }; |
| let align = match arg.format.align { |
| parse::AlignLeft => align("Left"), |
| parse::AlignRight => align("Right"), |
| parse::AlignCenter => align("Center"), |
| parse::AlignUnknown => align("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, "FormatSpec")); |
| let fmt = self.ecx.expr_struct( |
| sp, |
| path, |
| vec![ |
| self.ecx.field_imm(sp, self.ecx.ident_of("fill", sp), fill), |
| self.ecx.field_imm(sp, self.ecx.ident_of("align", sp), align), |
| self.ecx.field_imm(sp, self.ecx.ident_of("flags", sp), flags), |
| self.ecx.field_imm(sp, self.ecx.ident_of("precision", sp), prec), |
| self.ecx.field_imm(sp, self.ecx.ident_of("width", sp), width), |
| ], |
| ); |
| |
| let path = self.ecx.path_global(sp, Context::rtpath(self.ecx, "Argument")); |
| Some(self.ecx.expr_struct( |
| sp, |
| path, |
| vec![ |
| self.ecx.field_imm(sp, self.ecx.ident_of("position", sp), pos), |
| self.ecx.field_imm(sp, self.ecx.ident_of("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 locals = Vec::with_capacity( |
| (0..self.args.len()).map(|i| self.arg_unique_types[i].len()).sum() |
| ); |
| let mut counts = Vec::with_capacity(self.count_args.len()); |
| let mut pats = Vec::with_capacity(self.args.len()); |
| let mut heads = Vec::with_capacity(self.args.len()); |
| |
| let names_pos: Vec<_> = (0..self.args.len()) |
| .map(|i| self.ecx.ident_of(&format!("arg{}", i), self.macsp)) |
| .collect(); |
| |
| // First, build up the static array which will become our precompiled |
| // format "string" |
| let pieces = self.ecx.expr_vec_slice(self.fmtsp, self.str_pieces); |
| |
| // Before consuming the expressions, we have to remember spans for |
| // count arguments as they are now generated separate from other |
| // arguments, hence have no access to the `P<ast::Expr>`'s. |
| let spans_pos: Vec<_> = self.args.iter().map(|e| e.span.clone()).collect(); |
| |
| // Right now there is a bug such that for the expression: |
| // foo(bar(&1)) |
| // the lifetime of `1` doesn't outlast the call to `bar`, so it's not |
| // valid for the call to `foo`. To work around this all arguments to the |
| // format! string are shoved into locals. Furthermore, we shove the address |
| // of each variable because we don't want to move out of the arguments |
| // passed to this function. |
| for (i, e) in self.args.into_iter().enumerate() { |
| let name = names_pos[i]; |
| let span = self.ecx.with_def_site_ctxt(e.span); |
| pats.push(self.ecx.pat_ident(span, name)); |
| for ref arg_ty in self.arg_unique_types[i].iter() { |
| locals.push(Context::format_arg(self.ecx, self.macsp, e.span, arg_ty, name)); |
| } |
| heads.push(self.ecx.expr_addr_of(e.span, e)); |
| } |
| for pos in self.count_args { |
| let index = match pos { |
| Exact(i) => i, |
| _ => panic!("should never happen"), |
| }; |
| let name = names_pos[index]; |
| let span = spans_pos[index]; |
| counts.push(Context::format_arg(self.ecx, self.macsp, span, &Count, name)); |
| } |
| |
| // Now create a vector containing all the arguments |
| let args = locals.into_iter().chain(counts.into_iter()); |
| |
| let args_array = self.ecx.expr_vec(self.macsp, args.collect()); |
| |
| // Constructs an AST equivalent to: |
| // |
| // match (&arg0, &arg1) { |
| // (tmp0, tmp1) => args_array |
| // } |
| // |
| // It was: |
| // |
| // let tmp0 = &arg0; |
| // let tmp1 = &arg1; |
| // args_array |
| // |
| // Because of #11585 the new temporary lifetime rule, the enclosing |
| // statements for these temporaries become the let's themselves. |
| // If one or more of them are RefCell's, RefCell borrow() will also |
| // end there; they don't last long enough for args_array to use them. |
| // The match expression solves the scope problem. |
| // |
| // Note, it may also very well be transformed to: |
| // |
| // match arg0 { |
| // ref tmp0 => { |
| // match arg1 => { |
| // ref tmp1 => args_array } } } |
| // |
| // But the nested match expression is proved to perform not as well |
| // as series of let's; the first approach does. |
| let pat = self.ecx.pat_tuple(self.macsp, pats); |
| let arm = self.ecx.arm(self.macsp, pat, args_array); |
| let head = self.ecx.expr(self.macsp, ast::ExprKind::Tup(heads)); |
| let result = self.ecx.expr_match(self.macsp, head, vec![arm]); |
| |
| let args_slice = self.ecx.expr_addr_of(self.macsp, result); |
| |
| // 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_vec_slice(self.macsp, self.pieces); |
| |
| ("new_v1_formatted", vec![pieces, args_slice, fmt]) |
| }; |
| |
| 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: ast::Ident, |
| ) -> P<ast::Expr> { |
| sp = ecx.with_def_site_ctxt(sp); |
| let arg = ecx.expr_ident(sp, arg); |
| 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 path = ecx.std_path(&[sym::fmt, Symbol::intern(trait_), sym::fmt]); |
| let format_fn = ecx.path_global(sp, path); |
| let path = ecx.std_path(&[sym::fmt, sym::ArgumentV1, sym::new]); |
| ecx.expr_call_global(macsp, path, vec![arg, ecx.expr_path(format_fn)]) |
| } |
| } |
| |
| 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) |
| } |
| |
| /// 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<P<ast::Expr>>, |
| names: FxHashMap<Symbol, usize>, |
| 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 (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) = err { |
| let sugg_fmt = match args.len() { |
| 0 => "{}".to_string(), |
| _ => format!("{}{{}}", "{} ".repeat(args.len())), |
| }; |
| 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 (is_literal, fmt_snippet) = match ecx.source_map().span_to_snippet(fmt_sp) { |
| Ok(s) => (s.starts_with("\"") || s.starts_with("r#"), Some(s)), |
| _ => (false, None), |
| }; |
| |
| let str_style = match fmt_style { |
| ast::StrStyle::Cooked => None, |
| ast::StrStyle::Raw(raw) => { |
| Some(raw as usize) |
| }, |
| }; |
| |
| /// Finds the indices of all characters that have been processed and differ between the actual |
| /// written code (code snippet) and the `InternedString` that get's processed in the `Parser` |
| /// in order to properly synthethise the intra-string `Span`s for error diagnostics. |
| fn find_skips(snippet: &str, is_raw: bool) -> Vec<usize> { |
| let mut eat_ws = false; |
| let mut s = snippet.chars().enumerate().peekable(); |
| let mut skips = vec![]; |
| while let Some((pos, c)) = s.next() { |
| match (c, s.peek()) { |
| // skip whitespace and empty lines ending in '\\' |
| ('\\', Some((next_pos, '\n'))) if !is_raw => { |
| eat_ws = true; |
| skips.push(pos); |
| skips.push(*next_pos); |
| let _ = s.next(); |
| } |
| ('\\', Some((next_pos, '\n'))) | |
| ('\\', Some((next_pos, 'n'))) | |
| ('\\', Some((next_pos, 't'))) if eat_ws => { |
| skips.push(pos); |
| skips.push(*next_pos); |
| let _ = s.next(); |
| } |
| (' ', _) | |
| ('\n', _) | |
| ('\t', _) if eat_ws => { |
| skips.push(pos); |
| } |
| ('\\', Some((next_pos, 'n'))) | |
| ('\\', Some((next_pos, 't'))) | |
| ('\\', Some((next_pos, '0'))) | |
| ('\\', Some((next_pos, '\\'))) | |
| ('\\', Some((next_pos, '\''))) | |
| ('\\', Some((next_pos, '\"'))) => { |
| skips.push(*next_pos); |
| let _ = s.next(); |
| } |
| ('\\', Some((_, 'x'))) if !is_raw => { |
| for _ in 0..3 { // consume `\xAB` literal |
| if let Some((pos, _)) = s.next() { |
| skips.push(pos); |
| } else { |
| break; |
| } |
| } |
| } |
| ('\\', Some((_, 'u'))) if !is_raw => { |
| if let Some((pos, _)) = s.next() { |
| skips.push(pos); |
| } |
| if let Some((next_pos, next_c)) = s.next() { |
| if next_c == '{' { |
| skips.push(next_pos); |
| let mut i = 0; // consume up to 6 hexanumeric chars + closing `}` |
| while let (Some((next_pos, c)), true) = (s.next(), i < 7) { |
| if c.is_digit(16) { |
| skips.push(next_pos); |
| } else if c == '}' { |
| skips.push(next_pos); |
| break; |
| } else { |
| break; |
| } |
| i += 1; |
| } |
| } else if next_c.is_digit(16) { |
| skips.push(next_pos); |
| // We suggest adding `{` and `}` when appropriate, accept it here as if |
| // it were correct |
| let mut i = 0; // consume up to 6 hexanumeric chars |
| while let (Some((next_pos, c)), _) = (s.next(), i < 6) { |
| if c.is_digit(16) { |
| skips.push(next_pos); |
| } else { |
| break; |
| } |
| i += 1; |
| } |
| } |
| } |
| } |
| _ if eat_ws => { // `take_while(|c| c.is_whitespace())` |
| eat_ws = false; |
| } |
| _ => {} |
| } |
| } |
| skips |
| } |
| |
| let skips = if let (true, Some(ref snippet)) = (is_literal, fmt_snippet.as_ref()) { |
| let r_start = str_style.map(|r| r + 1).unwrap_or(0); |
| let r_end = str_style.map(|r| r).unwrap_or(0); |
| let s = &snippet[r_start + 1..snippet.len() - r_end - 1]; |
| find_skips(s, str_style.is_some()) |
| } else { |
| vec![] |
| }; |
| |
| let fmt_str = &fmt_str.as_str(); // for the suggestions below |
| let mut parser = parse::Parser::new(fmt_str, str_style, skips, append_newline); |
| |
| 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 = fmt_span.from_inner(err.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 { |
| let sp = fmt_span.from_inner(span); |
| e.span_label(sp, label); |
| } |
| e.emit(); |
| return DummyResult::raw_expr(sp, true); |
| } |
| |
| let arg_spans = parser.arg_places.iter() |
| .map(|span| fmt_span.from_inner(*span)) |
| .collect(); |
| |
| let named_pos: FxHashSet<usize> = names.values().cloned().collect(); |
| |
| let mut cx = Context { |
| ecx, |
| args, |
| 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, |
| }; |
| |
| // 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) => { |
| match arg.position { |
| parse::Position::ArgumentIs(_) => true, |
| _ => false, |
| } |
| } |
| } |
| }); |
| |
| 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.len() >= 1 { |
| 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 errs_len == 1 { |
| let (sp, msg) = errs.into_iter().next().unwrap(); |
| 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::$kind::iter_subs(fmt_str, padding) { |
| let trn = match sub.translate() { |
| Some(trn) => trn, |
| |
| // If it has no translation, don't call it out specifically. |
| None => continue, |
| }; |
| |
| let pos = sub.position(); |
| let sub = String::from(sub.as_str()); |
| if explained.contains(&sub) { |
| continue; |
| } |
| explained.insert(sub.clone()); |
| |
| if !found_foreign { |
| found_foreign = true; |
| show_doc_note = true; |
| } |
| |
| if let Some(inner_sp) = pos { |
| let sp = fmt_sp.from_inner(inner_sp); |
| suggestions.push((sp, trn)); |
| } else { |
| diag.help(&format!("`{}` should be written as `{}`", sub, trn)); |
| } |
| } |
| |
| if show_doc_note { |
| diag.note(concat!( |
| stringify!($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(); |
| } |
| |
| cx.into_expr() |
| } |
