867 lines
34 KiB
Rust
867 lines
34 KiB
Rust
// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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use self::ArgumentType::*;
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use self::Position::*;
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use fmt_macros as parse;
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use syntax::ast;
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use syntax::ext::base::*;
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use syntax::ext::base;
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use syntax::ext::build::AstBuilder;
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use syntax::parse::token;
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use syntax::ptr::P;
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use syntax::symbol::{Symbol, keywords};
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use syntax_pos::Span;
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use syntax::tokenstream;
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use std::collections::{HashMap, HashSet};
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use std::collections::hash_map::Entry;
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#[derive(PartialEq)]
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enum ArgumentType {
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Placeholder(String),
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Count,
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}
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enum Position {
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Exact(usize),
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Named(String),
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}
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struct Context<'a, 'b: 'a> {
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ecx: &'a mut ExtCtxt<'b>,
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/// The macro's call site. References to unstable formatting internals must
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/// use this span to pass the stability checker.
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macsp: Span,
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/// The span of the format string literal.
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fmtsp: Span,
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/// List of parsed argument expressions.
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/// Named expressions are resolved early, and are appended to the end of
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/// argument expressions.
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///
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/// Example showing the various data structures in motion:
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///
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/// * Original: `"{foo:o} {:o} {foo:x} {0:x} {1:o} {:x} {1:x} {0:o}"`
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/// * Implicit argument resolution: `"{foo:o} {0:o} {foo:x} {0:x} {1:o} {1:x} {1:x} {0:o}"`
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/// * Name resolution: `"{2:o} {0:o} {2:x} {0:x} {1:o} {1:x} {1:x} {0:o}"`
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/// * `arg_types` (in JSON): `[[0, 1, 0], [0, 1, 1], [0, 1]]`
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/// * `arg_unique_types` (in simplified JSON): `[["o", "x"], ["o", "x"], ["o", "x"]]`
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/// * `names` (in JSON): `{"foo": 2}`
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args: Vec<P<ast::Expr>>,
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/// Placeholder slot numbers indexed by argument.
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arg_types: Vec<Vec<usize>>,
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/// Unique format specs seen for each argument.
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arg_unique_types: Vec<Vec<ArgumentType>>,
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/// Map from named arguments to their resolved indices.
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names: HashMap<String, usize>,
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/// The latest consecutive literal strings, or empty if there weren't any.
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literal: String,
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/// Collection of the compiled `rt::Argument` structures
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pieces: Vec<P<ast::Expr>>,
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/// Collection of string literals
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str_pieces: Vec<P<ast::Expr>>,
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/// Stays `true` if all formatting parameters are default (as in "{}{}").
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all_pieces_simple: bool,
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/// Mapping between positional argument references and indices into the
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/// final generated static argument array. We record the starting indices
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/// corresponding to each positional argument, and number of references
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/// consumed so far for each argument, to facilitate correct `Position`
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/// mapping in `trans_piece`. In effect this can be seen as a "flattened"
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/// version of `arg_unique_types`.
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///
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/// Again with the example described above in docstring for `args`:
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///
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/// * `arg_index_map` (in JSON): `[[0, 1, 0], [2, 3, 3], [4, 5]]`
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arg_index_map: Vec<Vec<usize>>,
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/// Starting offset of count argument slots.
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count_args_index_offset: usize,
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/// Count argument slots and tracking data structures.
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/// Count arguments are separately tracked for de-duplication in case
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/// multiple references are made to one argument. For example, in this
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/// format string:
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///
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/// * Original: `"{:.*} {:.foo$} {1:.*} {:.0$}"`
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/// * Implicit argument resolution: `"{1:.0$} {2:.foo$} {1:.3$} {4:.0$}"`
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/// * Name resolution: `"{1:.0$} {2:.5$} {1:.3$} {4:.0$}"`
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/// * `count_positions` (in JSON): `{0: 0, 5: 1, 3: 2}`
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/// * `count_args`: `vec![Exact(0), Exact(5), Exact(3)]`
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count_args: Vec<Position>,
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/// Relative slot numbers for count arguments.
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count_positions: HashMap<usize, usize>,
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/// Number of count slots assigned.
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count_positions_count: usize,
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/// Current position of the implicit positional arg pointer, as if it
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/// still existed in this phase of processing.
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/// Used only for `all_pieces_simple` tracking in `trans_piece`.
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curarg: usize,
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}
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/// Parses the arguments from the given list of tokens, returning None
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/// if there's a parse error so we can continue parsing other format!
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/// expressions.
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///
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/// If parsing succeeds, the return value is:
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///
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/// ```text
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/// Some((fmtstr, parsed arguments, index map for named arguments))
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/// ```
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fn parse_args(ecx: &mut ExtCtxt,
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sp: Span,
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tts: &[tokenstream::TokenTree])
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-> Option<(P<ast::Expr>, Vec<P<ast::Expr>>, HashMap<String, usize>)> {
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let mut args = Vec::<P<ast::Expr>>::new();
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let mut names = HashMap::<String, usize>::new();
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let mut p = ecx.new_parser_from_tts(tts);
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if p.token == token::Eof {
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ecx.span_err(sp, "requires at least a format string argument");
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return None;
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}
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let fmtstr = panictry!(p.parse_expr());
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let mut named = false;
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while p.token != token::Eof {
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if !p.eat(&token::Comma) {
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ecx.span_err(sp, "expected token: `,`");
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return None;
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}
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if p.token == token::Eof {
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break;
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} // accept trailing commas
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if named || (p.token.is_ident() && p.look_ahead(1, |t| *t == token::Eq)) {
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named = true;
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let ident = match p.token {
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token::Ident(i) => {
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p.bump();
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i
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}
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_ if named => {
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ecx.span_err(p.span,
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"expected ident, positional arguments \
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cannot follow named arguments");
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return None;
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}
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_ => {
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ecx.span_err(p.span,
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&format!("expected ident for named argument, found `{}`",
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p.this_token_to_string()));
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return None;
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}
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};
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let name: &str = &ident.name.as_str();
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panictry!(p.expect(&token::Eq));
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let e = panictry!(p.parse_expr());
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if let Some(prev) = names.get(name) {
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ecx.struct_span_err(e.span, &format!("duplicate argument named `{}`", name))
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.span_note(args[*prev].span, "previously here")
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.emit();
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continue;
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}
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// Resolve names into slots early.
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// Since all the positional args are already seen at this point
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// if the input is valid, we can simply append to the positional
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// args. And remember the names.
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let slot = args.len();
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names.insert(name.to_string(), slot);
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args.push(e);
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} else {
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args.push(panictry!(p.parse_expr()));
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}
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}
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Some((fmtstr, args, names))
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}
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impl<'a, 'b> Context<'a, 'b> {
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fn resolve_name_inplace(&self, p: &mut parse::Piece) {
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// NOTE: the `unwrap_or` branch is needed in case of invalid format
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// arguments, e.g. `format_args!("{foo}")`.
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let lookup = |s| *self.names.get(s).unwrap_or(&0);
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match *p {
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parse::String(_) => {}
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parse::NextArgument(ref mut arg) => {
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if let parse::ArgumentNamed(s) = arg.position {
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arg.position = parse::ArgumentIs(lookup(s));
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}
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if let parse::CountIsName(s) = arg.format.width {
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arg.format.width = parse::CountIsParam(lookup(s));
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}
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if let parse::CountIsName(s) = arg.format.precision {
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arg.format.precision = parse::CountIsParam(lookup(s));
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}
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}
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}
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}
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/// Verifies one piece of a parse string, and remembers it if valid.
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/// All errors are not emitted as fatal so we can continue giving errors
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/// about this and possibly other format strings.
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fn verify_piece(&mut self, p: &parse::Piece) {
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match *p {
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parse::String(..) => {}
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parse::NextArgument(ref arg) => {
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// width/precision first, if they have implicit positional
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// parameters it makes more sense to consume them first.
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self.verify_count(arg.format.width);
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self.verify_count(arg.format.precision);
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// argument second, if it's an implicit positional parameter
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// it's written second, so it should come after width/precision.
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let pos = match arg.position {
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parse::ArgumentIs(i) => Exact(i),
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parse::ArgumentNamed(s) => Named(s.to_string()),
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};
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let ty = Placeholder(arg.format.ty.to_string());
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self.verify_arg_type(pos, ty);
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}
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}
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}
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fn verify_count(&mut self, c: parse::Count) {
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match c {
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parse::CountImplied |
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parse::CountIs(..) => {}
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parse::CountIsParam(i) => {
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self.verify_arg_type(Exact(i), Count);
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}
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parse::CountIsName(s) => {
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self.verify_arg_type(Named(s.to_string()), Count);
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}
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}
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}
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fn describe_num_args(&self) -> String {
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match self.args.len() {
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0 => "no arguments given".to_string(),
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1 => "there is 1 argument".to_string(),
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x => format!("there are {} arguments", x),
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}
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}
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/// Actually verifies and tracks a given format placeholder
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/// (a.k.a. argument).
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fn verify_arg_type(&mut self, arg: Position, ty: ArgumentType) {
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match arg {
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Exact(arg) => {
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if self.args.len() <= arg {
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let msg = format!("invalid reference to argument `{}` ({})",
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arg,
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self.describe_num_args());
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self.ecx.span_err(self.fmtsp, &msg[..]);
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return;
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}
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match ty {
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Placeholder(_) => {
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// record every (position, type) combination only once
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let ref mut seen_ty = self.arg_unique_types[arg];
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let i = match seen_ty.iter().position(|x| *x == ty) {
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Some(i) => i,
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None => {
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let i = seen_ty.len();
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seen_ty.push(ty);
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i
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}
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};
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self.arg_types[arg].push(i);
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}
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Count => {
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match self.count_positions.entry(arg) {
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Entry::Vacant(e) => {
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let i = self.count_positions_count;
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e.insert(i);
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self.count_args.push(Exact(arg));
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self.count_positions_count += 1;
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}
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Entry::Occupied(_) => {}
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}
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}
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}
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}
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Named(name) => {
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let idx = match self.names.get(&name) {
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Some(e) => *e,
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None => {
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let msg = format!("there is no argument named `{}`", name);
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self.ecx.span_err(self.fmtsp, &msg[..]);
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return;
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}
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};
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// Treat as positional arg.
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self.verify_arg_type(Exact(idx), ty)
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}
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}
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}
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/// Builds the mapping between format placeholders and argument objects.
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fn build_index_map(&mut self) {
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// NOTE: Keep the ordering the same as `into_expr`'s expansion would do!
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let args_len = self.args.len();
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self.arg_index_map.reserve(args_len);
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let mut sofar = 0usize;
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// Map the arguments
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for i in 0..args_len {
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let ref arg_types = self.arg_types[i];
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let mut arg_offsets = Vec::with_capacity(arg_types.len());
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for offset in arg_types {
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arg_offsets.push(sofar + *offset);
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}
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self.arg_index_map.push(arg_offsets);
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sofar += self.arg_unique_types[i].len();
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}
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// Record starting index for counts, which appear just after arguments
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self.count_args_index_offset = sofar;
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}
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fn rtpath(ecx: &ExtCtxt, s: &str) -> Vec<ast::Ident> {
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ecx.std_path(&["fmt", "rt", "v1", s])
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}
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fn trans_count(&self, c: parse::Count) -> P<ast::Expr> {
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let sp = self.macsp;
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let count = |c, arg| {
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let mut path = Context::rtpath(self.ecx, "Count");
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path.push(self.ecx.ident_of(c));
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match arg {
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Some(arg) => self.ecx.expr_call_global(sp, path, vec![arg]),
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None => self.ecx.expr_path(self.ecx.path_global(sp, path)),
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}
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};
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match c {
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parse::CountIs(i) => count("Is", Some(self.ecx.expr_usize(sp, i))),
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parse::CountIsParam(i) => {
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// This needs mapping too, as `i` is referring to a macro
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// argument.
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let i = match self.count_positions.get(&i) {
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Some(&i) => i,
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None => 0, // error already emitted elsewhere
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};
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let i = i + self.count_args_index_offset;
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count("Param", Some(self.ecx.expr_usize(sp, i)))
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}
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parse::CountImplied => count("Implied", None),
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// should never be the case, names are already resolved
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parse::CountIsName(_) => panic!("should never happen"),
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}
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}
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/// Translate the accumulated string literals to a literal expression
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fn trans_literal_string(&mut self) -> P<ast::Expr> {
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let sp = self.fmtsp;
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let s = Symbol::intern(&self.literal);
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self.literal.clear();
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self.ecx.expr_str(sp, s)
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}
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/// Translate a `parse::Piece` to a static `rt::Argument` or append
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/// to the `literal` string.
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fn trans_piece(&mut self,
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piece: &parse::Piece,
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arg_index_consumed: &mut Vec<usize>)
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-> Option<P<ast::Expr>> {
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let sp = self.macsp;
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match *piece {
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parse::String(s) => {
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self.literal.push_str(s);
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None
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}
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parse::NextArgument(ref arg) => {
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// Translate the position
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let pos = {
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let pos = |c, arg| {
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let mut path = Context::rtpath(self.ecx, "Position");
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path.push(self.ecx.ident_of(c));
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match arg {
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Some(i) => {
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let arg = self.ecx.expr_usize(sp, i);
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self.ecx.expr_call_global(sp, path, vec![arg])
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}
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None => self.ecx.expr_path(self.ecx.path_global(sp, path)),
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}
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};
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match arg.position {
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parse::ArgumentIs(i) => {
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// Map to index in final generated argument array
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// in case of multiple types specified
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let arg_idx = match arg_index_consumed.get_mut(i) {
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None => 0, // error already emitted elsewhere
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Some(offset) => {
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let ref idx_map = self.arg_index_map[i];
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// unwrap_or branch: error already emitted elsewhere
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let arg_idx = *idx_map.get(*offset).unwrap_or(&0);
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*offset += 1;
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arg_idx
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}
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};
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pos("At", Some(arg_idx))
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}
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// should never be the case, because names are already
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// resolved.
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parse::ArgumentNamed(_) => panic!("should never happen"),
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}
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};
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let simple_arg = parse::Argument {
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position: {
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// We don't have ArgumentNext any more, so we have to
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// track the current argument ourselves.
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let i = self.curarg;
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self.curarg += 1;
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parse::ArgumentIs(i)
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},
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format: parse::FormatSpec {
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fill: arg.format.fill,
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align: parse::AlignUnknown,
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flags: 0,
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precision: parse::CountImplied,
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width: parse::CountImplied,
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ty: arg.format.ty,
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},
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};
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let fill = match arg.format.fill {
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Some(c) => c,
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None => ' ',
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};
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if *arg != simple_arg || fill != ' ' {
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self.all_pieces_simple = false;
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}
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// Translate the format
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let fill = self.ecx.expr_lit(sp, ast::LitKind::Char(fill));
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let align = |name| {
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let mut p = Context::rtpath(self.ecx, "Alignment");
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p.push(self.ecx.ident_of(name));
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self.ecx.path_global(sp, p)
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};
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let align = match arg.format.align {
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parse::AlignLeft => align("Left"),
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parse::AlignRight => align("Right"),
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parse::AlignCenter => align("Center"),
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parse::AlignUnknown => align("Unknown"),
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};
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let align = self.ecx.expr_path(align);
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let flags = self.ecx.expr_u32(sp, arg.format.flags);
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let prec = self.trans_count(arg.format.precision);
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let width = self.trans_count(arg.format.width);
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let path = self.ecx.path_global(sp, Context::rtpath(self.ecx, "FormatSpec"));
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let fmt =
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self.ecx.expr_struct(sp,
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path,
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vec![self.ecx
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.field_imm(sp, self.ecx.ident_of("fill"), fill),
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self.ecx.field_imm(sp,
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self.ecx.ident_of("align"),
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align),
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self.ecx.field_imm(sp,
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self.ecx.ident_of("flags"),
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flags),
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self.ecx.field_imm(sp,
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self.ecx.ident_of("precision"),
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prec),
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self.ecx.field_imm(sp,
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self.ecx.ident_of("width"),
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width)]);
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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"),
|
|
pos),
|
|
self.ecx.field_imm(sp,
|
|
self.ecx.ident_of("format"),
|
|
fmt)]))
|
|
}
|
|
}
|
|
}
|
|
|
|
fn static_array(ecx: &mut ExtCtxt,
|
|
name: &str,
|
|
piece_ty: P<ast::Ty>,
|
|
pieces: Vec<P<ast::Expr>>)
|
|
-> P<ast::Expr> {
|
|
let sp = piece_ty.span;
|
|
let ty = ecx.ty_rptr(sp,
|
|
ecx.ty(sp, ast::TyKind::Slice(piece_ty)),
|
|
Some(ecx.lifetime(sp, keywords::StaticLifetime.ident())),
|
|
ast::Mutability::Immutable);
|
|
let slice = ecx.expr_vec_slice(sp, pieces);
|
|
// static instead of const to speed up codegen by not requiring this to be inlined
|
|
let st = ast::ItemKind::Static(ty, ast::Mutability::Immutable, slice);
|
|
|
|
let name = ecx.ident_of(name);
|
|
let item = ecx.item(sp, name, vec![], st);
|
|
let stmt = ast::Stmt {
|
|
id: ast::DUMMY_NODE_ID,
|
|
node: ast::StmtKind::Item(item),
|
|
span: sp,
|
|
};
|
|
|
|
// Wrap the declaration in a block so that it forms a single expression.
|
|
ecx.expr_block(ecx.block(sp, vec![stmt, ecx.stmt_expr(ecx.expr_ident(sp, name))]))
|
|
}
|
|
|
|
/// Actually builds the expression which the format_args! block will be
|
|
/// expanded to
|
|
fn into_expr(mut self) -> P<ast::Expr> {
|
|
let mut locals = Vec::new();
|
|
let mut counts = Vec::new();
|
|
let mut pats = Vec::new();
|
|
let mut heads = Vec::new();
|
|
|
|
// First, build up the static array which will become our precompiled
|
|
// format "string"
|
|
let static_lifetime = self.ecx.lifetime(self.fmtsp, keywords::StaticLifetime.ident());
|
|
let piece_ty = self.ecx.ty_rptr(self.fmtsp,
|
|
self.ecx.ty_ident(self.fmtsp, self.ecx.ident_of("str")),
|
|
Some(static_lifetime),
|
|
ast::Mutability::Immutable);
|
|
let pieces = Context::static_array(self.ecx, "__STATIC_FMTSTR", piece_ty, 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 = self.ecx.ident_of(&format!("__arg{}", i));
|
|
let span =
|
|
Span { ctxt: e.span.ctxt.apply_mark(self.ecx.current_expansion.mark), ..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 name = self.ecx.ident_of(&match pos {
|
|
Exact(i) => format!("__arg{}", i),
|
|
_ => panic!("should never happen"),
|
|
});
|
|
let span = match pos {
|
|
Exact(i) => spans_pos[i],
|
|
_ => panic!("should never happen"),
|
|
};
|
|
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.fmtsp, 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.fmtsp, pats);
|
|
let arm = self.ecx.arm(self.fmtsp, vec![pat], args_array);
|
|
let head = self.ecx.expr(self.fmtsp, ast::ExprKind::Tup(heads));
|
|
let result = self.ecx.expr_match(self.fmtsp, head, vec![arm]);
|
|
|
|
let args_slice = self.ecx.expr_addr_of(self.fmtsp, 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 piece_ty = self.ecx
|
|
.ty_path(self.ecx.path_global(self.macsp, Context::rtpath(self.ecx, "Argument")));
|
|
let fmt = Context::static_array(self.ecx, "__STATIC_FMTARGS", piece_ty, self.pieces);
|
|
|
|
("new_v1_formatted", vec![pieces, args_slice, fmt])
|
|
};
|
|
|
|
let path = self.ecx.std_path(&["fmt", "Arguments", 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.ctxt = sp.ctxt.apply_mark(ecx.current_expansion.mark);
|
|
let arg = ecx.expr_ident(sp, arg);
|
|
let trait_ = match *ty {
|
|
Placeholder(ref tyname) => {
|
|
match &tyname[..] {
|
|
"" => "Display",
|
|
"?" => "Debug",
|
|
"e" => "LowerExp",
|
|
"E" => "UpperExp",
|
|
"o" => "Octal",
|
|
"p" => "Pointer",
|
|
"b" => "Binary",
|
|
"x" => "LowerHex",
|
|
"X" => "UpperHex",
|
|
_ => {
|
|
ecx.span_err(sp, &format!("unknown format trait `{}`", *tyname));
|
|
"Dummy"
|
|
}
|
|
}
|
|
}
|
|
Count => {
|
|
let path = ecx.std_path(&["fmt", "ArgumentV1", "from_usize"]);
|
|
return ecx.expr_call_global(macsp, path, vec![arg]);
|
|
}
|
|
};
|
|
|
|
let path = ecx.std_path(&["fmt", trait_, "fmt"]);
|
|
let format_fn = ecx.path_global(sp, path);
|
|
let path = ecx.std_path(&["fmt", "ArgumentV1", "new"]);
|
|
ecx.expr_call_global(macsp, path, vec![arg, ecx.expr_path(format_fn)])
|
|
}
|
|
}
|
|
|
|
pub fn expand_format_args<'cx>(ecx: &'cx mut ExtCtxt,
|
|
mut sp: Span,
|
|
tts: &[tokenstream::TokenTree])
|
|
-> Box<base::MacResult + 'cx> {
|
|
sp.ctxt = sp.ctxt.apply_mark(ecx.current_expansion.mark);
|
|
match parse_args(ecx, sp, tts) {
|
|
Some((efmt, args, names)) => {
|
|
MacEager::expr(expand_preparsed_format_args(ecx, sp, efmt, args, names))
|
|
}
|
|
None => DummyResult::expr(sp),
|
|
}
|
|
}
|
|
|
|
/// 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: HashMap<String, usize>)
|
|
-> 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.ctxt = macsp.ctxt.apply_mark(ecx.current_expansion.mark);
|
|
let msg = "format argument must be a string literal.";
|
|
let fmt = match expr_to_spanned_string(ecx, efmt, msg) {
|
|
Some(fmt) => fmt,
|
|
None => return DummyResult::raw_expr(sp),
|
|
};
|
|
|
|
let mut cx = Context {
|
|
ecx: ecx,
|
|
args: args,
|
|
arg_types: arg_types,
|
|
arg_unique_types: arg_unique_types,
|
|
names: names,
|
|
curarg: 0,
|
|
arg_index_map: Vec::new(),
|
|
count_args: Vec::new(),
|
|
count_positions: HashMap::new(),
|
|
count_positions_count: 0,
|
|
count_args_index_offset: 0,
|
|
literal: String::new(),
|
|
pieces: Vec::new(),
|
|
str_pieces: Vec::new(),
|
|
all_pieces_simple: true,
|
|
macsp: macsp,
|
|
fmtsp: fmt.span,
|
|
};
|
|
|
|
let fmt_str = &*fmt.node.0.as_str();
|
|
let mut parser = parse::Parser::new(fmt_str);
|
|
let mut pieces = vec![];
|
|
|
|
loop {
|
|
match parser.next() {
|
|
Some(mut piece) => {
|
|
if !parser.errors.is_empty() {
|
|
break;
|
|
}
|
|
cx.verify_piece(&piece);
|
|
cx.resolve_name_inplace(&mut piece);
|
|
pieces.push(piece);
|
|
}
|
|
None => break,
|
|
}
|
|
}
|
|
|
|
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.trans_piece(&piece, &mut arg_index_consumed) {
|
|
let s = cx.trans_literal_string();
|
|
cx.str_pieces.push(s);
|
|
cx.pieces.push(piece);
|
|
}
|
|
}
|
|
|
|
if !parser.errors.is_empty() {
|
|
let (err, note) = parser.errors.remove(0);
|
|
let mut e = cx.ecx.struct_span_err(cx.fmtsp, &format!("invalid format string: {}", err));
|
|
if let Some(note) = note {
|
|
e.note(¬e);
|
|
}
|
|
e.emit();
|
|
return DummyResult::raw_expr(sp);
|
|
}
|
|
if !cx.literal.is_empty() {
|
|
let s = cx.trans_literal_string();
|
|
cx.str_pieces.push(s);
|
|
}
|
|
|
|
// Make sure that all arguments were used and all arguments have types.
|
|
let num_pos_args = cx.args.len() - cx.names.len();
|
|
let mut errs = vec![];
|
|
for (i, ty) in cx.arg_types.iter().enumerate() {
|
|
if ty.len() == 0 {
|
|
if cx.count_positions.contains_key(&i) {
|
|
continue;
|
|
}
|
|
let msg = if i >= num_pos_args {
|
|
// named argument
|
|
"named argument never used"
|
|
} else {
|
|
// positional argument
|
|
"argument never used"
|
|
};
|
|
errs.push((cx.args[i].span, msg));
|
|
}
|
|
}
|
|
if errs.len() > 0 {
|
|
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();
|
|
cx.ecx.struct_span_err(sp, msg)
|
|
} else {
|
|
let mut diag = cx.ecx.struct_span_err(cx.fmtsp,
|
|
"multiple unused formatting arguments");
|
|
|
|
// Ignoring message, as it gets repetitive
|
|
// Then use MultiSpan to not clutter up errors
|
|
for (sp, _) in errs {
|
|
diag.span_label(sp, "unused");
|
|
}
|
|
|
|
diag
|
|
}
|
|
};
|
|
|
|
// 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 = HashSet::new();
|
|
|
|
// Used to ensure we only report translations for *one* kind of foreign format.
|
|
let mut found_foreign = false;
|
|
|
|
macro_rules! check_foreign {
|
|
($kind:ident) => {{
|
|
let mut show_doc_note = false;
|
|
|
|
for sub in foreign::$kind::iter_subs(fmt_str) {
|
|
let trn = match sub.translate() {
|
|
Some(trn) => trn,
|
|
|
|
// If it has no translation, don't call it out specifically.
|
|
None => continue,
|
|
};
|
|
|
|
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;
|
|
}
|
|
|
|
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`"));
|
|
}
|
|
}};
|
|
}
|
|
|
|
check_foreign!(printf);
|
|
if !found_foreign {
|
|
check_foreign!(shell);
|
|
}
|
|
}
|
|
|
|
diag.emit();
|
|
}
|
|
|
|
cx.into_expr()
|
|
}
|