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Diffstat (limited to 'src/libsyntax_ext/format.rs')
| -rw-r--r-- | src/libsyntax_ext/format.rs | 1233 |
1 files changed, 0 insertions, 1233 deletions
diff --git a/src/libsyntax_ext/format.rs b/src/libsyntax_ext/format.rs deleted file mode 100644 index 1d1f68a4906..00000000000 --- a/src/libsyntax_ext/format.rs +++ /dev/null @@ -1,1233 +0,0 @@ -use ArgumentType::*; -use Position::*; - -use fmt_macros as parse; - -use errors::pluralize; -use errors::Applicability; -use errors::DiagnosticBuilder; - -use syntax::ast; -use syntax::ptr::P; -use syntax::symbol::{sym, Symbol}; -use syntax::token; -use syntax::tokenstream::TokenStream; -use syntax_expand::base::{self, *}; -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() -} |