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https://github.com/rust-lang/rust.git
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1553 lines
62 KiB
Rust
1553 lines
62 KiB
Rust
use ArgumentType::*;
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use Position::*;
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use rustc_ast as ast;
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use rustc_ast::ptr::P;
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use rustc_ast::tokenstream::TokenStream;
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use rustc_ast::visit::{self, Visitor};
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use rustc_ast::{token, BlockCheckMode, UnsafeSource};
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use rustc_data_structures::fx::{FxHashMap, FxHashSet};
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use rustc_errors::{pluralize, Applicability, MultiSpan, PResult};
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use rustc_expand::base::{self, *};
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use rustc_parse_format as parse;
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use rustc_span::symbol::{sym, Ident, Symbol};
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use rustc_span::{BytePos, InnerSpan, Span};
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use smallvec::SmallVec;
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use rustc_lint_defs::builtin::NAMED_ARGUMENTS_USED_POSITIONALLY;
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use rustc_lint_defs::{BufferedEarlyLint, BuiltinLintDiagnostics, LintId};
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use rustc_parse_format::Count;
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use std::borrow::Cow;
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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(&'static str),
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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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Capture(usize),
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Named(Symbol, InnerSpan),
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}
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/// Indicates how positional named argument (i.e. an named argument which is used by position
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/// instead of by name) is used in format string
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/// * `Arg` is the actual argument to print
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/// * `Width` is width format argument
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/// * `Precision` is precion format argument
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/// Example: `{Arg:Width$.Precision$}
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#[derive(Debug, Eq, PartialEq)]
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enum PositionalNamedArgType {
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Arg,
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Width,
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Precision,
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}
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/// Contains information necessary to create a lint for a positional named argument
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#[derive(Debug)]
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struct PositionalNamedArg {
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ty: PositionalNamedArgType,
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/// The piece of the using this argument (multiple pieces can use the same argument)
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cur_piece: usize,
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/// The InnerSpan for in the string to be replaced with the named argument
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/// This will be None when the position is implicit
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inner_span_to_replace: Option<rustc_parse_format::InnerSpan>,
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/// The name to use instead of the position
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replacement: Symbol,
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/// The span for the positional named argument (so the lint can point a message to it)
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positional_named_arg_span: Span,
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has_formatting: bool,
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}
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impl PositionalNamedArg {
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/// Determines:
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/// 1) span to be replaced with the name of the named argument and
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/// 2) span to be underlined for error messages
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fn get_positional_arg_spans(&self, cx: &Context<'_, '_>) -> (Option<Span>, Option<Span>) {
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if let Some(inner_span) = &self.inner_span_to_replace {
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let span =
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cx.fmtsp.from_inner(InnerSpan { start: inner_span.start, end: inner_span.end });
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(Some(span), Some(span))
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} else if self.ty == PositionalNamedArgType::Arg {
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// In the case of a named argument whose position is implicit, if the argument *has*
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// formatting, there will not be a span to replace. Instead, we insert the name after
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// the `{`, which will be the first character of arg_span. If the argument does *not*
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// have formatting, there may or may not be a span to replace. This is because
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// whitespace is allowed in arguments without formatting (such as `format!("{ }", 1);`)
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// but is not allowed in arguments with formatting (an error will be generated in cases
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// like `format!("{ :1.1}", 1.0f32);`.
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// For the message span, if there is formatting, we want to use the opening `{` and the
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// next character, which will the `:` indicating the start of formatting. If there is
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// not any formatting, we want to underline the entire span.
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cx.arg_spans.get(self.cur_piece).map_or((None, None), |arg_span| {
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if self.has_formatting {
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(
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Some(arg_span.with_lo(arg_span.lo() + BytePos(1)).shrink_to_lo()),
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Some(arg_span.with_hi(arg_span.lo() + BytePos(2))),
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)
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} else {
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let replace_start = arg_span.lo() + BytePos(1);
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let replace_end = arg_span.hi() - BytePos(1);
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let to_replace = arg_span.with_lo(replace_start).with_hi(replace_end);
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(Some(to_replace), Some(*arg_span))
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}
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})
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} else {
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(None, None)
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}
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}
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}
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/// Encapsulates all the named arguments that have been used positionally
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#[derive(Debug)]
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struct PositionalNamedArgsLint {
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positional_named_args: Vec<PositionalNamedArg>,
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}
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impl PositionalNamedArgsLint {
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/// For a given positional argument, check if the index is for a named argument.
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///
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/// Since positional arguments are required to come before named arguments, if the positional
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/// index is greater than or equal to the start of named arguments, we know it's a named
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/// argument used positionally.
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///
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/// Example:
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/// println!("{} {} {2}", 0, a=1, b=2);
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///
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/// In this case, the first piece (`{}`) would be ArgumentImplicitlyIs with an index of 0. The
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/// total number of arguments is 3 and the number of named arguments is 2, so the start of named
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/// arguments is index 1. Therefore, the index of 0 is okay.
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///
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/// The second piece (`{}`) would be ArgumentImplicitlyIs with an index of 1, which is the start
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/// of named arguments, and so we should add a lint to use the named argument `a`.
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///
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/// The third piece (`{2}`) would be ArgumentIs with an index of 2, which is greater than the
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/// start of named arguments, and so we should add a lint to use the named argument `b`.
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///
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/// This same check also works for width and precision formatting when either or both are
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/// CountIsParam, which contains an index into the arguments.
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fn maybe_add_positional_named_arg(
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&mut self,
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arg: Option<&FormatArg>,
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ty: PositionalNamedArgType,
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cur_piece: usize,
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inner_span_to_replace: Option<rustc_parse_format::InnerSpan>,
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has_formatting: bool,
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) {
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if let Some(arg) = arg {
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if let Some(name) = arg.name {
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self.push(name, ty, cur_piece, inner_span_to_replace, has_formatting)
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}
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}
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}
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/// Construct a PositionalNamedArg struct and push it into the vec of positional
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/// named arguments.
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fn push(
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&mut self,
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arg_name: Ident,
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ty: PositionalNamedArgType,
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cur_piece: usize,
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inner_span_to_replace: Option<rustc_parse_format::InnerSpan>,
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has_formatting: bool,
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) {
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// In FormatSpec, `precision_span` starts at the leading `.`, which we want to keep in
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// the lint suggestion, so increment `start` by 1 when `PositionalArgumentType` is
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// `Precision`.
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let inner_span_to_replace = if ty == PositionalNamedArgType::Precision {
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inner_span_to_replace
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.map(|is| rustc_parse_format::InnerSpan { start: is.start + 1, end: is.end })
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} else {
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inner_span_to_replace
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};
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self.positional_named_args.push(PositionalNamedArg {
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ty,
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cur_piece,
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inner_span_to_replace,
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replacement: arg_name.name,
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positional_named_arg_span: arg_name.span,
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has_formatting,
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});
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}
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}
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struct Context<'a, 'b> {
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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<FormatArg>,
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/// The number of arguments that were added by implicit capturing.
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num_captured_args: usize,
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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: FxHashMap<Symbol, 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 `build_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![0, 5, 3]`
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count_args: Vec<usize>,
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/// Relative slot numbers for count arguments.
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count_positions: FxHashMap<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 `build_piece`.
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curarg: usize,
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/// Current piece being evaluated, used for error reporting.
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curpiece: usize,
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/// Keep track of invalid references to positional arguments.
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invalid_refs: Vec<(usize, usize)>,
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/// Spans of all the formatting arguments, in order.
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arg_spans: Vec<Span>,
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/// All the formatting arguments that have formatting flags set, in order for diagnostics.
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arg_with_formatting: Vec<parse::FormatSpec<'a>>,
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/// Whether this format string came from a string literal, as opposed to a macro.
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is_literal: bool,
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unused_names_lint: PositionalNamedArgsLint,
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}
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pub struct FormatArg {
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expr: P<ast::Expr>,
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name: Option<Ident>,
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}
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/// Parses the arguments from the given list of tokens, returning the diagnostic
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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<'a>(
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ecx: &mut ExtCtxt<'a>,
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sp: Span,
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tts: TokenStream,
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) -> PResult<'a, (P<ast::Expr>, Vec<FormatArg>, FxHashMap<Symbol, usize>)> {
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let mut args = Vec::<FormatArg>::new();
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let mut names = FxHashMap::<Symbol, usize>::default();
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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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return Err(ecx.struct_span_err(sp, "requires at least a format string argument"));
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}
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let first_token = &p.token;
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let fmtstr = match first_token.kind {
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token::TokenKind::Literal(token::Lit {
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kind: token::LitKind::Str | token::LitKind::StrRaw(_),
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..
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}) => {
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// If the first token is a string literal, then a format expression
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// is constructed from it.
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//
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// This allows us to properly handle cases when the first comma
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// after the format string is mistakenly replaced with any operator,
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// which cause the expression parser to eat too much tokens.
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p.parse_literal_maybe_minus()?
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}
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_ => {
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// Otherwise, we fall back to the expression parser.
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p.parse_expr()?
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}
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};
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let mut first = true;
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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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if first {
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p.clear_expected_tokens();
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}
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match p.expect(&token::Comma) {
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Err(mut err) => {
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match token::TokenKind::Comma.similar_tokens() {
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Some(tks) if tks.contains(&p.token.kind) => {
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// If a similar token is found, then it may be a typo. We
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// consider it as a comma, and continue parsing.
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err.emit();
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p.bump();
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}
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// Otherwise stop the parsing and return the error.
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_ => return Err(err),
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}
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}
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Ok(recovered) => {
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assert!(recovered);
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}
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}
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}
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first = false;
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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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match p.token.ident() {
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Some((ident, _)) if p.look_ahead(1, |t| *t == token::Eq) => {
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named = true;
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p.bump();
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p.expect(&token::Eq)?;
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let e = p.parse_expr()?;
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if let Some(&prev) = names.get(&ident.name) {
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ecx.struct_span_err(e.span, &format!("duplicate argument named `{}`", ident))
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.span_label(args[prev].expr.span, "previously here")
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.span_label(e.span, "duplicate argument")
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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(ident.name, slot);
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args.push(FormatArg { expr: e, name: Some(ident) });
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}
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_ => {
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let e = p.parse_expr()?;
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if named {
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let mut err = ecx.struct_span_err(
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e.span,
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"positional arguments cannot follow named arguments",
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);
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err.span_label(e.span, "positional arguments must be before named arguments");
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for &pos in names.values() {
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err.span_label(args[pos].expr.span, "named argument");
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}
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err.emit();
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}
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args.push(FormatArg { expr: e, name: None });
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}
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}
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}
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Ok((fmtstr, args, names))
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}
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impl<'a, 'b> Context<'a, 'b> {
|
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/// The number of arguments that were explicitly given.
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fn num_args(&self) -> usize {
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self.args.len() - self.num_captured_args
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}
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fn resolve_name_inplace(&mut 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: &str| self.names.get(&Symbol::intern(s)).copied().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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|
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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<'a>) {
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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(
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arg.format.width,
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&arg.format.width_span,
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PositionalNamedArgType::Width,
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);
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self.verify_count(
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arg.format.precision,
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&arg.format.precision_span,
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PositionalNamedArgType::Precision,
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);
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let has_precision = arg.format.precision != Count::CountImplied;
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let has_width = arg.format.width != Count::CountImplied;
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if has_precision || has_width {
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// push before named params are resolved to aid diagnostics
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self.arg_with_formatting.push(arg.format);
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}
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|
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// argument second, if it's an implicit positional parameter
|
|
// 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) => {
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self.unused_names_lint.maybe_add_positional_named_arg(
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self.args.get(i),
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PositionalNamedArgType::Arg,
|
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self.curpiece,
|
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Some(arg.position_span),
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has_precision || has_width,
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);
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|
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Exact(i)
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}
|
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parse::ArgumentImplicitlyIs(i) => {
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self.unused_names_lint.maybe_add_positional_named_arg(
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self.args.get(i),
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PositionalNamedArgType::Arg,
|
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self.curpiece,
|
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None,
|
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has_precision || has_width,
|
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);
|
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Exact(i)
|
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}
|
|
parse::ArgumentNamed(s) => {
|
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let symbol = Symbol::intern(s);
|
|
let span = arg.position_span;
|
|
Named(symbol, InnerSpan::new(span.start, span.end))
|
|
}
|
|
};
|
|
|
|
let ty = Placeholder(match arg.format.ty {
|
|
"" => "Display",
|
|
"?" => "Debug",
|
|
"e" => "LowerExp",
|
|
"E" => "UpperExp",
|
|
"o" => "Octal",
|
|
"p" => "Pointer",
|
|
"b" => "Binary",
|
|
"x" => "LowerHex",
|
|
"X" => "UpperHex",
|
|
_ => {
|
|
let fmtsp = self.fmtsp;
|
|
let sp = arg
|
|
.format
|
|
.ty_span
|
|
.map(|sp| fmtsp.from_inner(InnerSpan::new(sp.start, sp.end)));
|
|
let mut err = self.ecx.struct_span_err(
|
|
sp.unwrap_or(fmtsp),
|
|
&format!("unknown format trait `{}`", arg.format.ty),
|
|
);
|
|
err.note(
|
|
"the only appropriate formatting traits are:\n\
|
|
- ``, which uses the `Display` trait\n\
|
|
- `?`, which uses the `Debug` trait\n\
|
|
- `e`, which uses the `LowerExp` trait\n\
|
|
- `E`, which uses the `UpperExp` trait\n\
|
|
- `o`, which uses the `Octal` trait\n\
|
|
- `p`, which uses the `Pointer` trait\n\
|
|
- `b`, which uses the `Binary` trait\n\
|
|
- `x`, which uses the `LowerHex` trait\n\
|
|
- `X`, which uses the `UpperHex` trait",
|
|
);
|
|
if let Some(sp) = sp {
|
|
for (fmt, name) in &[
|
|
("", "Display"),
|
|
("?", "Debug"),
|
|
("e", "LowerExp"),
|
|
("E", "UpperExp"),
|
|
("o", "Octal"),
|
|
("p", "Pointer"),
|
|
("b", "Binary"),
|
|
("x", "LowerHex"),
|
|
("X", "UpperHex"),
|
|
] {
|
|
// FIXME: rustfix (`run-rustfix`) fails to apply suggestions.
|
|
// > "Cannot replace slice of data that was already replaced"
|
|
err.tool_only_span_suggestion(
|
|
sp,
|
|
&format!("use the `{}` trait", name),
|
|
*fmt,
|
|
Applicability::MaybeIncorrect,
|
|
);
|
|
}
|
|
}
|
|
err.emit();
|
|
"<invalid>"
|
|
}
|
|
});
|
|
self.verify_arg_type(pos, ty);
|
|
self.curpiece += 1;
|
|
}
|
|
}
|
|
}
|
|
|
|
fn verify_count(
|
|
&mut self,
|
|
c: parse::Count<'_>,
|
|
inner_span: &Option<rustc_parse_format::InnerSpan>,
|
|
named_arg_type: PositionalNamedArgType,
|
|
) {
|
|
match c {
|
|
parse::CountImplied | parse::CountIs(..) => {}
|
|
parse::CountIsParam(i) | parse::CountIsStar(i) => {
|
|
self.unused_names_lint.maybe_add_positional_named_arg(
|
|
self.args.get(i),
|
|
named_arg_type,
|
|
self.curpiece,
|
|
*inner_span,
|
|
true,
|
|
);
|
|
self.verify_arg_type(Exact(i), Count);
|
|
}
|
|
parse::CountIsName(s, span) => {
|
|
self.verify_arg_type(
|
|
Named(Symbol::intern(s), InnerSpan::new(span.start, span.end)),
|
|
Count,
|
|
);
|
|
}
|
|
}
|
|
}
|
|
|
|
fn describe_num_args(&self) -> Cow<'_, str> {
|
|
match self.num_args() {
|
|
0 => "no arguments were given".into(),
|
|
1 => "there is 1 argument".into(),
|
|
x => format!("there are {} arguments", x).into(),
|
|
}
|
|
}
|
|
|
|
/// Handle invalid references to positional arguments. Output different
|
|
/// errors for the case where all arguments are positional and for when
|
|
/// there are named arguments or numbered positional arguments in the
|
|
/// format string.
|
|
fn report_invalid_references(&self, numbered_position_args: bool) {
|
|
let mut e;
|
|
let sp = if !self.arg_spans.is_empty() {
|
|
// Point at the formatting arguments.
|
|
MultiSpan::from_spans(self.arg_spans.clone())
|
|
} else {
|
|
MultiSpan::from_span(self.fmtsp)
|
|
};
|
|
let refs =
|
|
self.invalid_refs.iter().map(|(r, pos)| (r.to_string(), self.arg_spans.get(*pos)));
|
|
|
|
let mut zero_based_note = false;
|
|
|
|
let count = self.pieces.len()
|
|
+ self
|
|
.arg_with_formatting
|
|
.iter()
|
|
.filter(|fmt| matches!(fmt.precision, parse::CountIsStar(_)))
|
|
.count();
|
|
if self.names.is_empty() && !numbered_position_args && count != self.num_args() {
|
|
e = self.ecx.struct_span_err(
|
|
sp,
|
|
&format!(
|
|
"{} positional argument{} in format string, but {}",
|
|
count,
|
|
pluralize!(count),
|
|
self.describe_num_args(),
|
|
),
|
|
);
|
|
for arg in &self.args {
|
|
// Point at the arguments that will be formatted.
|
|
e.span_label(arg.expr.span, "");
|
|
}
|
|
} else {
|
|
let (mut refs, spans): (Vec<_>, Vec<_>) = refs.unzip();
|
|
// Avoid `invalid reference to positional arguments 7 and 7 (there is 1 argument)`
|
|
// for `println!("{7:7$}", 1);`
|
|
refs.sort();
|
|
refs.dedup();
|
|
let spans: Vec<_> = spans.into_iter().filter_map(|sp| sp.copied()).collect();
|
|
let sp = if self.arg_spans.is_empty() || spans.is_empty() {
|
|
MultiSpan::from_span(self.fmtsp)
|
|
} else {
|
|
MultiSpan::from_spans(spans)
|
|
};
|
|
let arg_list = if refs.len() == 1 {
|
|
format!("argument {}", refs[0])
|
|
} else {
|
|
let reg = refs.pop().unwrap();
|
|
format!("arguments {head} and {tail}", head = refs.join(", "), tail = reg)
|
|
};
|
|
|
|
e = self.ecx.struct_span_err(
|
|
sp,
|
|
&format!(
|
|
"invalid reference to positional {} ({})",
|
|
arg_list,
|
|
self.describe_num_args()
|
|
),
|
|
);
|
|
zero_based_note = true;
|
|
};
|
|
|
|
for fmt in &self.arg_with_formatting {
|
|
if let Some(span) = fmt.precision_span {
|
|
let span = self.fmtsp.from_inner(InnerSpan::new(span.start, span.end));
|
|
match fmt.precision {
|
|
parse::CountIsParam(pos) if pos >= self.num_args() => {
|
|
e.span_label(
|
|
span,
|
|
&format!(
|
|
"this precision flag expects an `usize` argument at position {}, \
|
|
but {}",
|
|
pos,
|
|
self.describe_num_args(),
|
|
),
|
|
);
|
|
zero_based_note = true;
|
|
}
|
|
parse::CountIsStar(pos) => {
|
|
let count = self.pieces.len()
|
|
+ self
|
|
.arg_with_formatting
|
|
.iter()
|
|
.filter(|fmt| matches!(fmt.precision, parse::CountIsStar(_)))
|
|
.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.expr.span,
|
|
"this parameter corresponds to the precision flag",
|
|
);
|
|
}
|
|
zero_based_note = true;
|
|
}
|
|
_ => {}
|
|
}
|
|
}
|
|
if let Some(span) = fmt.width_span {
|
|
let span = self.fmtsp.from_inner(InnerSpan::new(span.start, span.end));
|
|
match fmt.width {
|
|
parse::CountIsParam(pos) if pos >= self.num_args() => {
|
|
e.span_label(
|
|
span,
|
|
&format!(
|
|
"this width flag expects an `usize` argument at position {}, \
|
|
but {}",
|
|
pos,
|
|
self.describe_num_args(),
|
|
),
|
|
);
|
|
zero_based_note = true;
|
|
}
|
|
_ => {}
|
|
}
|
|
}
|
|
}
|
|
if zero_based_note {
|
|
e.note("positional arguments are zero-based");
|
|
}
|
|
if !self.arg_with_formatting.is_empty() {
|
|
e.note(
|
|
"for information about formatting flags, visit \
|
|
https://doc.rust-lang.org/std/fmt/index.html",
|
|
);
|
|
}
|
|
|
|
e.emit();
|
|
}
|
|
|
|
/// Actually verifies and tracks a given format placeholder
|
|
/// (a.k.a. argument).
|
|
fn verify_arg_type(&mut self, arg: Position, ty: ArgumentType) {
|
|
if let Exact(arg) = arg {
|
|
if arg >= self.num_args() {
|
|
self.invalid_refs.push((arg, self.curpiece));
|
|
return;
|
|
}
|
|
}
|
|
|
|
match arg {
|
|
Exact(arg) | Capture(arg) => {
|
|
match ty {
|
|
Placeholder(_) => {
|
|
// record every (position, type) combination only once
|
|
let seen_ty = &mut self.arg_unique_types[arg];
|
|
let i = seen_ty.iter().position(|x| *x == ty).unwrap_or_else(|| {
|
|
let i = seen_ty.len();
|
|
seen_ty.push(ty);
|
|
i
|
|
});
|
|
self.arg_types[arg].push(i);
|
|
}
|
|
Count => {
|
|
if let Entry::Vacant(e) = self.count_positions.entry(arg) {
|
|
let i = self.count_positions_count;
|
|
e.insert(i);
|
|
self.count_args.push(arg);
|
|
self.count_positions_count += 1;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
Named(name, span) => {
|
|
match self.names.get(&name) {
|
|
Some(&idx) => {
|
|
// Treat as positional arg.
|
|
self.verify_arg_type(Capture(idx), ty)
|
|
}
|
|
None => {
|
|
// For the moment capturing variables from format strings expanded from macros is
|
|
// disabled (see RFC #2795)
|
|
if self.is_literal {
|
|
// Treat this name as a variable to capture from the surrounding scope
|
|
let idx = self.args.len();
|
|
self.arg_types.push(Vec::new());
|
|
self.arg_unique_types.push(Vec::new());
|
|
let span = if self.is_literal {
|
|
self.fmtsp.from_inner(span)
|
|
} else {
|
|
self.fmtsp
|
|
};
|
|
self.num_captured_args += 1;
|
|
self.args.push(FormatArg {
|
|
expr: self.ecx.expr_ident(span, Ident::new(name, span)),
|
|
name: Some(Ident::new(name, span)),
|
|
});
|
|
self.names.insert(name, idx);
|
|
self.verify_arg_type(Capture(idx), ty)
|
|
} else {
|
|
let msg = format!("there is no argument named `{}`", name);
|
|
let sp = if self.is_literal {
|
|
self.fmtsp.from_inner(span)
|
|
} else {
|
|
self.fmtsp
|
|
};
|
|
let mut err = self.ecx.struct_span_err(sp, &msg);
|
|
|
|
err.note(&format!(
|
|
"did you intend to capture a variable `{}` from \
|
|
the surrounding scope?",
|
|
name
|
|
));
|
|
err.note(
|
|
"to avoid ambiguity, `format_args!` cannot capture variables \
|
|
when the format string is expanded from a macro",
|
|
);
|
|
|
|
err.emit();
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Builds the mapping between format placeholders and argument objects.
|
|
fn build_index_map(&mut self) {
|
|
// NOTE: Keep the ordering the same as `into_expr`'s expansion would do!
|
|
let args_len = self.args.len();
|
|
self.arg_index_map.reserve(args_len);
|
|
|
|
let mut sofar = 0usize;
|
|
|
|
// Map the arguments
|
|
for i in 0..args_len {
|
|
let arg_types = &self.arg_types[i];
|
|
let arg_offsets = arg_types.iter().map(|offset| sofar + *offset).collect::<Vec<_>>();
|
|
self.arg_index_map.push(arg_offsets);
|
|
sofar += self.arg_unique_types[i].len();
|
|
}
|
|
|
|
// Record starting index for counts, which appear just after arguments
|
|
self.count_args_index_offset = sofar;
|
|
}
|
|
|
|
fn rtpath(ecx: &ExtCtxt<'_>, s: Symbol) -> Vec<Ident> {
|
|
ecx.std_path(&[sym::fmt, sym::rt, sym::v1, s])
|
|
}
|
|
|
|
fn build_count(&self, c: parse::Count<'_>) -> P<ast::Expr> {
|
|
let sp = self.macsp;
|
|
let count = |c, arg| {
|
|
let mut path = Context::rtpath(self.ecx, sym::Count);
|
|
path.push(Ident::new(c, sp));
|
|
match arg {
|
|
Some(arg) => self.ecx.expr_call_global(sp, path, vec![arg]),
|
|
None => self.ecx.expr_path(self.ecx.path_global(sp, path)),
|
|
}
|
|
};
|
|
match c {
|
|
parse::CountIs(i) => count(sym::Is, Some(self.ecx.expr_usize(sp, i))),
|
|
parse::CountIsParam(i) | parse::CountIsStar(i) => {
|
|
// This needs mapping too, as `i` is referring to a macro
|
|
// argument. If `i` is not found in `count_positions` then
|
|
// the error had already been emitted elsewhere.
|
|
let i = self.count_positions.get(&i).cloned().unwrap_or(0)
|
|
+ self.count_args_index_offset;
|
|
count(sym::Param, Some(self.ecx.expr_usize(sp, i)))
|
|
}
|
|
parse::CountImplied => count(sym::Implied, None),
|
|
// should never be the case, names are already resolved
|
|
parse::CountIsName(..) => panic!("should never happen"),
|
|
}
|
|
}
|
|
|
|
/// Build a literal expression from the accumulated string literals
|
|
fn build_literal_string(&mut self) -> P<ast::Expr> {
|
|
let sp = self.fmtsp;
|
|
let s = Symbol::intern(&self.literal);
|
|
self.literal.clear();
|
|
self.ecx.expr_str(sp, s)
|
|
}
|
|
|
|
/// Builds a static `rt::Argument` from a `parse::Piece` or append
|
|
/// to the `literal` string.
|
|
fn build_piece(
|
|
&mut self,
|
|
piece: &parse::Piece<'a>,
|
|
arg_index_consumed: &mut Vec<usize>,
|
|
) -> Option<P<ast::Expr>> {
|
|
let sp = self.macsp;
|
|
match *piece {
|
|
parse::String(s) => {
|
|
self.literal.push_str(s);
|
|
None
|
|
}
|
|
parse::NextArgument(ref arg) => {
|
|
// Build the position
|
|
let pos = {
|
|
match arg.position {
|
|
parse::ArgumentIs(i, ..) | parse::ArgumentImplicitlyIs(i) => {
|
|
// Map to index in final generated argument array
|
|
// in case of multiple types specified
|
|
let arg_idx = match arg_index_consumed.get_mut(i) {
|
|
None => 0, // error already emitted elsewhere
|
|
Some(offset) => {
|
|
let idx_map = &self.arg_index_map[i];
|
|
// unwrap_or branch: error already emitted elsewhere
|
|
let arg_idx = *idx_map.get(*offset).unwrap_or(&0);
|
|
*offset += 1;
|
|
arg_idx
|
|
}
|
|
};
|
|
self.ecx.expr_usize(sp, arg_idx)
|
|
}
|
|
|
|
// should never be the case, because names are already
|
|
// resolved.
|
|
parse::ArgumentNamed(..) => panic!("should never happen"),
|
|
}
|
|
};
|
|
|
|
let simple_arg = parse::Argument {
|
|
position: {
|
|
// We don't have ArgumentNext any more, so we have to
|
|
// track the current argument ourselves.
|
|
let i = self.curarg;
|
|
self.curarg += 1;
|
|
parse::ArgumentIs(i)
|
|
},
|
|
position_span: arg.position_span,
|
|
format: parse::FormatSpec {
|
|
fill: None,
|
|
align: parse::AlignUnknown,
|
|
flags: 0,
|
|
precision: parse::CountImplied,
|
|
precision_span: arg.format.precision_span,
|
|
width: parse::CountImplied,
|
|
width_span: arg.format.width_span,
|
|
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 !pos_simple || arg.format != simple_arg.format {
|
|
self.all_pieces_simple = false;
|
|
}
|
|
|
|
// Build the format
|
|
let fill = self.ecx.expr_char(sp, fill);
|
|
let align = |name| {
|
|
let mut p = Context::rtpath(self.ecx, sym::Alignment);
|
|
p.push(Ident::new(name, sp));
|
|
self.ecx.path_global(sp, p)
|
|
};
|
|
let align = match arg.format.align {
|
|
parse::AlignLeft => align(sym::Left),
|
|
parse::AlignRight => align(sym::Right),
|
|
parse::AlignCenter => align(sym::Center),
|
|
parse::AlignUnknown => align(sym::Unknown),
|
|
};
|
|
let align = self.ecx.expr_path(align);
|
|
let flags = self.ecx.expr_u32(sp, arg.format.flags);
|
|
let prec = self.build_count(arg.format.precision);
|
|
let width = self.build_count(arg.format.width);
|
|
let path = self.ecx.path_global(sp, Context::rtpath(self.ecx, sym::FormatSpec));
|
|
let fmt = self.ecx.expr_struct(
|
|
sp,
|
|
path,
|
|
vec![
|
|
self.ecx.field_imm(sp, Ident::new(sym::fill, sp), fill),
|
|
self.ecx.field_imm(sp, Ident::new(sym::align, sp), align),
|
|
self.ecx.field_imm(sp, Ident::new(sym::flags, sp), flags),
|
|
self.ecx.field_imm(sp, Ident::new(sym::precision, sp), prec),
|
|
self.ecx.field_imm(sp, Ident::new(sym::width, sp), width),
|
|
],
|
|
);
|
|
|
|
let path = self.ecx.path_global(sp, Context::rtpath(self.ecx, sym::Argument));
|
|
Some(self.ecx.expr_struct(
|
|
sp,
|
|
path,
|
|
vec![
|
|
self.ecx.field_imm(sp, Ident::new(sym::position, sp), pos),
|
|
self.ecx.field_imm(sp, Ident::new(sym::format, sp), fmt),
|
|
],
|
|
))
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Actually builds the expression which the format_args! block will be
|
|
/// expanded to.
|
|
fn into_expr(self) -> P<ast::Expr> {
|
|
let mut original_args = self.args;
|
|
let mut fmt_args = Vec::with_capacity(
|
|
self.arg_unique_types.iter().map(|v| v.len()).sum::<usize>() + self.count_args.len(),
|
|
);
|
|
|
|
// First, build up the static array which will become our precompiled
|
|
// format "string"
|
|
let pieces = self.ecx.expr_array_ref(self.fmtsp, self.str_pieces);
|
|
|
|
// We need to construct a &[ArgumentV1] to pass into the fmt::Arguments
|
|
// constructor. In general the expressions in this slice might be
|
|
// permuted from their order in original_args (such as in the case of
|
|
// "{1} {0}"), or may have multiple entries referring to the same
|
|
// element of original_args ("{0} {0}").
|
|
//
|
|
// The following vector has one item per element of our output slice,
|
|
// identifying the index of which element of original_args it's passing,
|
|
// and that argument's type.
|
|
let mut fmt_arg_index_and_ty = SmallVec::<[(usize, &ArgumentType); 8]>::new();
|
|
for (i, unique_types) in self.arg_unique_types.iter().enumerate() {
|
|
fmt_arg_index_and_ty.extend(unique_types.iter().map(|ty| (i, ty)));
|
|
}
|
|
fmt_arg_index_and_ty.extend(self.count_args.iter().map(|&i| (i, &Count)));
|
|
|
|
// Figure out whether there are permuted or repeated elements. If not,
|
|
// we can generate simpler code.
|
|
//
|
|
// The sequence has no indices out of order or repeated if: for every
|
|
// adjacent pair of elements, the first one's index is less than the
|
|
// second one's index.
|
|
let nicely_ordered =
|
|
fmt_arg_index_and_ty.array_windows().all(|[(i, _i_ty), (j, _j_ty)]| i < j);
|
|
|
|
// We want to emit:
|
|
//
|
|
// [ArgumentV1::new(&$arg0, …), ArgumentV1::new(&$arg1, …), …]
|
|
//
|
|
// However, it's only legal to do so if $arg0, $arg1, … were written in
|
|
// exactly that order by the programmer. When arguments are permuted, we
|
|
// want them evaluated in the order written by the programmer, not in
|
|
// the order provided to fmt::Arguments. When arguments are repeated, we
|
|
// want the expression evaluated only once.
|
|
//
|
|
// Further, if any arg _after the first one_ contains a yield point such
|
|
// as `await` or `yield`, the above short form is inconvenient for the
|
|
// caller because it would keep a temporary of type ArgumentV1 alive
|
|
// across the yield point. ArgumentV1 can't implement Send since it
|
|
// holds a type-erased arbitrary type.
|
|
//
|
|
// Thus in the not nicely ordered case, and in the yielding case, we
|
|
// emit the following instead:
|
|
//
|
|
// match (&$arg0, &$arg1, …) {
|
|
// args => [ArgumentV1::new(args.$i, …), ArgumentV1::new(args.$j, …), …]
|
|
// }
|
|
//
|
|
// for the sequence of indices $i, $j, … governed by fmt_arg_index_and_ty.
|
|
// This more verbose representation ensures that all arguments are
|
|
// evaluated a single time each, in the order written by the programmer,
|
|
// and that the surrounding future/generator (if any) is Send whenever
|
|
// possible.
|
|
let no_need_for_match = nicely_ordered
|
|
&& !original_args.iter().skip(1).any(|arg| may_contain_yield_point(&arg.expr));
|
|
|
|
for (arg_index, arg_ty) in fmt_arg_index_and_ty {
|
|
let e = &mut original_args[arg_index].expr;
|
|
let span = e.span;
|
|
let arg = if no_need_for_match {
|
|
let expansion_span = e.span.with_ctxt(self.macsp.ctxt());
|
|
// The indices are strictly ordered so e has not been taken yet.
|
|
self.ecx.expr_addr_of(expansion_span, P(e.take()))
|
|
} else {
|
|
let def_site = self.ecx.with_def_site_ctxt(span);
|
|
let args_tuple = self.ecx.expr_ident(def_site, Ident::new(sym::args, def_site));
|
|
let member = Ident::new(sym::integer(arg_index), def_site);
|
|
self.ecx.expr(def_site, ast::ExprKind::Field(args_tuple, member))
|
|
};
|
|
fmt_args.push(Context::format_arg(self.ecx, self.macsp, span, arg_ty, arg));
|
|
}
|
|
|
|
let args_array = self.ecx.expr_array(self.macsp, fmt_args);
|
|
let args_slice = self.ecx.expr_addr_of(
|
|
self.macsp,
|
|
if no_need_for_match {
|
|
args_array
|
|
} else {
|
|
// In the !no_need_for_match case, none of the exprs were moved
|
|
// away in the previous loop.
|
|
//
|
|
// This uses the arg span for `&arg` so that borrowck errors
|
|
// point to the specific expression passed to the macro (the
|
|
// span is otherwise unavailable in the MIR used by borrowck).
|
|
let heads = original_args
|
|
.into_iter()
|
|
.map(|arg| {
|
|
self.ecx.expr_addr_of(arg.expr.span.with_ctxt(self.macsp.ctxt()), arg.expr)
|
|
})
|
|
.collect();
|
|
|
|
let pat = self.ecx.pat_ident(self.macsp, Ident::new(sym::args, self.macsp));
|
|
let arm = self.ecx.arm(self.macsp, pat, args_array);
|
|
let head = self.ecx.expr(self.macsp, ast::ExprKind::Tup(heads));
|
|
self.ecx.expr_match(self.macsp, head, vec![arm])
|
|
},
|
|
);
|
|
|
|
// Now create the fmt::Arguments struct with all our locals we created.
|
|
let (fn_name, fn_args) = if self.all_pieces_simple {
|
|
("new_v1", vec![pieces, args_slice])
|
|
} else {
|
|
// Build up the static array which will store our precompiled
|
|
// nonstandard placeholders, if there are any.
|
|
let fmt = self.ecx.expr_array_ref(self.macsp, self.pieces);
|
|
|
|
let path = self.ecx.std_path(&[sym::fmt, sym::UnsafeArg, sym::new]);
|
|
let unsafe_arg = self.ecx.expr_call_global(self.macsp, path, Vec::new());
|
|
let unsafe_expr = self.ecx.expr_block(P(ast::Block {
|
|
stmts: vec![self.ecx.stmt_expr(unsafe_arg)],
|
|
id: ast::DUMMY_NODE_ID,
|
|
rules: BlockCheckMode::Unsafe(UnsafeSource::CompilerGenerated),
|
|
span: self.macsp,
|
|
tokens: None,
|
|
could_be_bare_literal: false,
|
|
}));
|
|
|
|
("new_v1_formatted", vec![pieces, args_slice, fmt, unsafe_expr])
|
|
};
|
|
|
|
let path = self.ecx.std_path(&[sym::fmt, sym::Arguments, Symbol::intern(fn_name)]);
|
|
self.ecx.expr_call_global(self.macsp, path, fn_args)
|
|
}
|
|
|
|
fn format_arg(
|
|
ecx: &ExtCtxt<'_>,
|
|
macsp: Span,
|
|
mut sp: Span,
|
|
ty: &ArgumentType,
|
|
arg: P<ast::Expr>,
|
|
) -> P<ast::Expr> {
|
|
sp = ecx.with_def_site_ctxt(sp);
|
|
let trait_ = match *ty {
|
|
Placeholder(trait_) if trait_ == "<invalid>" => return DummyResult::raw_expr(sp, true),
|
|
Placeholder(trait_) => trait_,
|
|
Count => {
|
|
let path = ecx.std_path(&[sym::fmt, sym::ArgumentV1, sym::from_usize]);
|
|
return ecx.expr_call_global(macsp, path, vec![arg]);
|
|
}
|
|
};
|
|
let new_fn_name = match trait_ {
|
|
"Display" => "new_display",
|
|
"Debug" => "new_debug",
|
|
"LowerExp" => "new_lower_exp",
|
|
"UpperExp" => "new_upper_exp",
|
|
"Octal" => "new_octal",
|
|
"Pointer" => "new_pointer",
|
|
"Binary" => "new_binary",
|
|
"LowerHex" => "new_lower_hex",
|
|
"UpperHex" => "new_upper_hex",
|
|
_ => unreachable!(),
|
|
};
|
|
|
|
let path = ecx.std_path(&[sym::fmt, sym::ArgumentV1, Symbol::intern(new_fn_name)]);
|
|
ecx.expr_call_global(sp, path, vec![arg])
|
|
}
|
|
}
|
|
|
|
fn expand_format_args_impl<'cx>(
|
|
ecx: &'cx mut ExtCtxt<'_>,
|
|
mut sp: Span,
|
|
tts: TokenStream,
|
|
nl: bool,
|
|
) -> Box<dyn base::MacResult + 'cx> {
|
|
sp = ecx.with_def_site_ctxt(sp);
|
|
match parse_args(ecx, sp, tts) {
|
|
Ok((efmt, args, names)) => {
|
|
MacEager::expr(expand_preparsed_format_args(ecx, sp, efmt, args, names, nl))
|
|
}
|
|
Err(mut err) => {
|
|
err.emit();
|
|
DummyResult::any(sp)
|
|
}
|
|
}
|
|
}
|
|
|
|
pub fn expand_format_args<'cx>(
|
|
ecx: &'cx mut ExtCtxt<'_>,
|
|
sp: Span,
|
|
tts: TokenStream,
|
|
) -> Box<dyn base::MacResult + 'cx> {
|
|
expand_format_args_impl(ecx, sp, tts, false)
|
|
}
|
|
|
|
pub fn expand_format_args_nl<'cx>(
|
|
ecx: &'cx mut ExtCtxt<'_>,
|
|
sp: Span,
|
|
tts: TokenStream,
|
|
) -> Box<dyn base::MacResult + 'cx> {
|
|
expand_format_args_impl(ecx, sp, tts, true)
|
|
}
|
|
|
|
fn create_lints_for_named_arguments_used_positionally(cx: &mut Context<'_, '_>) {
|
|
for named_arg in &cx.unused_names_lint.positional_named_args {
|
|
let (position_sp_to_replace, position_sp_for_msg) = named_arg.get_positional_arg_spans(cx);
|
|
|
|
let msg = format!("named argument `{}` is not used by name", named_arg.replacement);
|
|
|
|
cx.ecx.buffered_early_lint.push(BufferedEarlyLint {
|
|
span: MultiSpan::from_span(named_arg.positional_named_arg_span),
|
|
msg: msg.into(),
|
|
node_id: ast::CRATE_NODE_ID,
|
|
lint_id: LintId::of(&NAMED_ARGUMENTS_USED_POSITIONALLY),
|
|
diagnostic: BuiltinLintDiagnostics::NamedArgumentUsedPositionally {
|
|
position_sp_to_replace,
|
|
position_sp_for_msg,
|
|
named_arg_sp: named_arg.positional_named_arg_span,
|
|
named_arg_name: named_arg.replacement.to_string(),
|
|
is_formatting_arg: named_arg.ty != PositionalNamedArgType::Arg,
|
|
},
|
|
});
|
|
}
|
|
}
|
|
|
|
/// Take the various parts of `format_args!(efmt, args..., name=names...)`
|
|
/// and construct the appropriate formatting expression.
|
|
pub fn expand_preparsed_format_args(
|
|
ecx: &mut ExtCtxt<'_>,
|
|
sp: Span,
|
|
efmt: P<ast::Expr>,
|
|
args: Vec<FormatArg>,
|
|
names: FxHashMap<Symbol, usize>,
|
|
append_newline: bool,
|
|
) -> P<ast::Expr> {
|
|
// NOTE: this verbose way of initializing `Vec<Vec<ArgumentType>>` is because
|
|
// `ArgumentType` does not derive `Clone`.
|
|
let arg_types: Vec<_> = (0..args.len()).map(|_| Vec::new()).collect();
|
|
let arg_unique_types: Vec<_> = (0..args.len()).map(|_| Vec::new()).collect();
|
|
|
|
let mut macsp = ecx.call_site();
|
|
macsp = ecx.with_def_site_ctxt(macsp);
|
|
|
|
let msg = "format argument must be a string literal";
|
|
let fmt_sp = efmt.span;
|
|
let efmt_kind_is_lit: bool = matches!(efmt.kind, ast::ExprKind::Lit(_));
|
|
let (fmt_str, fmt_style, fmt_span) = match expr_to_spanned_string(ecx, efmt, msg) {
|
|
Ok(mut fmt) if append_newline => {
|
|
fmt.0 = Symbol::intern(&format!("{}\n", fmt.0));
|
|
fmt
|
|
}
|
|
Ok(fmt) => fmt,
|
|
Err(err) => {
|
|
if let Some((mut err, suggested)) = err {
|
|
let sugg_fmt = match args.len() {
|
|
0 => "{}".to_string(),
|
|
_ => format!("{}{{}}", "{} ".repeat(args.len())),
|
|
};
|
|
if !suggested {
|
|
err.span_suggestion(
|
|
fmt_sp.shrink_to_lo(),
|
|
"you might be missing a string literal to format with",
|
|
format!("\"{}\", ", sugg_fmt),
|
|
Applicability::MaybeIncorrect,
|
|
);
|
|
}
|
|
err.emit();
|
|
}
|
|
return DummyResult::raw_expr(sp, true);
|
|
}
|
|
};
|
|
|
|
let str_style = match fmt_style {
|
|
ast::StrStyle::Cooked => None,
|
|
ast::StrStyle::Raw(raw) => Some(raw as usize),
|
|
};
|
|
|
|
let fmt_str = fmt_str.as_str(); // for the suggestions below
|
|
let fmt_snippet = ecx.source_map().span_to_snippet(fmt_sp).ok();
|
|
let mut parser = parse::Parser::new(
|
|
fmt_str,
|
|
str_style,
|
|
fmt_snippet,
|
|
append_newline,
|
|
parse::ParseMode::Format,
|
|
);
|
|
|
|
let mut unverified_pieces = Vec::new();
|
|
while let Some(piece) = parser.next() {
|
|
if !parser.errors.is_empty() {
|
|
break;
|
|
} else {
|
|
unverified_pieces.push(piece);
|
|
}
|
|
}
|
|
|
|
if !parser.errors.is_empty() {
|
|
let err = parser.errors.remove(0);
|
|
let sp = if efmt_kind_is_lit {
|
|
fmt_span.from_inner(InnerSpan::new(err.span.start, err.span.end))
|
|
} else {
|
|
// The format string could be another macro invocation, e.g.:
|
|
// format!(concat!("abc", "{}"), 4);
|
|
// However, `err.span` is an inner span relative to the *result* of
|
|
// the macro invocation, which is why we would get a nonsensical
|
|
// result calling `fmt_span.from_inner(err.span)` as above, and
|
|
// might even end up inside a multibyte character (issue #86085).
|
|
// Therefore, we conservatively report the error for the entire
|
|
// argument span here.
|
|
fmt_span
|
|
};
|
|
let mut e = ecx.struct_span_err(sp, &format!("invalid format string: {}", err.description));
|
|
e.span_label(sp, err.label + " in format string");
|
|
if let Some(note) = err.note {
|
|
e.note(¬e);
|
|
}
|
|
if let Some((label, span)) = err.secondary_label {
|
|
if efmt_kind_is_lit {
|
|
e.span_label(fmt_span.from_inner(InnerSpan::new(span.start, span.end)), label);
|
|
}
|
|
}
|
|
if err.should_be_replaced_with_positional_argument {
|
|
let captured_arg_span =
|
|
fmt_span.from_inner(InnerSpan::new(err.span.start, err.span.end));
|
|
let n_positional_args =
|
|
args.iter().rposition(|arg| arg.name.is_none()).map_or(0, |i| i + 1);
|
|
if let Ok(arg) = ecx.source_map().span_to_snippet(captured_arg_span) {
|
|
let span = match args[..n_positional_args].last() {
|
|
Some(arg) => arg.expr.span,
|
|
None => fmt_sp,
|
|
};
|
|
e.multipart_suggestion_verbose(
|
|
"consider using a positional formatting argument instead",
|
|
vec![
|
|
(captured_arg_span, n_positional_args.to_string()),
|
|
(span.shrink_to_hi(), format!(", {}", arg)),
|
|
],
|
|
Applicability::MachineApplicable,
|
|
);
|
|
}
|
|
}
|
|
e.emit();
|
|
return DummyResult::raw_expr(sp, true);
|
|
}
|
|
|
|
let arg_spans = parser
|
|
.arg_places
|
|
.iter()
|
|
.map(|span| fmt_span.from_inner(InnerSpan::new(span.start, span.end)))
|
|
.collect();
|
|
|
|
let mut cx = Context {
|
|
ecx,
|
|
args,
|
|
num_captured_args: 0,
|
|
arg_types,
|
|
arg_unique_types,
|
|
names,
|
|
curarg: 0,
|
|
curpiece: 0,
|
|
arg_index_map: Vec::new(),
|
|
count_args: Vec::new(),
|
|
count_positions: FxHashMap::default(),
|
|
count_positions_count: 0,
|
|
count_args_index_offset: 0,
|
|
literal: String::new(),
|
|
pieces: Vec::with_capacity(unverified_pieces.len()),
|
|
str_pieces: Vec::with_capacity(unverified_pieces.len()),
|
|
all_pieces_simple: true,
|
|
macsp,
|
|
fmtsp: fmt_span,
|
|
invalid_refs: Vec::new(),
|
|
arg_spans,
|
|
arg_with_formatting: Vec::new(),
|
|
is_literal: parser.is_literal,
|
|
unused_names_lint: PositionalNamedArgsLint { positional_named_args: vec![] },
|
|
};
|
|
|
|
// This needs to happen *after* the Parser has consumed all pieces to create all the spans
|
|
let pieces = unverified_pieces
|
|
.into_iter()
|
|
.map(|mut piece| {
|
|
cx.verify_piece(&piece);
|
|
cx.resolve_name_inplace(&mut piece);
|
|
piece
|
|
})
|
|
.collect::<Vec<_>>();
|
|
|
|
let numbered_position_args = pieces.iter().any(|arg: &parse::Piece<'_>| match *arg {
|
|
parse::String(_) => false,
|
|
parse::NextArgument(arg) => matches!(arg.position, parse::Position::ArgumentIs(..)),
|
|
});
|
|
|
|
cx.build_index_map();
|
|
|
|
let mut arg_index_consumed = vec![0usize; cx.arg_index_map.len()];
|
|
|
|
for piece in pieces {
|
|
if let Some(piece) = cx.build_piece(&piece, &mut arg_index_consumed) {
|
|
let s = cx.build_literal_string();
|
|
cx.str_pieces.push(s);
|
|
cx.pieces.push(piece);
|
|
}
|
|
}
|
|
|
|
if !cx.literal.is_empty() {
|
|
let s = cx.build_literal_string();
|
|
cx.str_pieces.push(s);
|
|
}
|
|
|
|
if !cx.invalid_refs.is_empty() {
|
|
cx.report_invalid_references(numbered_position_args);
|
|
}
|
|
|
|
// Make sure that all arguments were used and all arguments have types.
|
|
let errs = cx
|
|
.arg_types
|
|
.iter()
|
|
.enumerate()
|
|
.filter(|(i, ty)| ty.is_empty() && !cx.count_positions.contains_key(&i))
|
|
.map(|(i, _)| {
|
|
let msg = if cx.args[i].name.is_some() {
|
|
"named argument never used"
|
|
} else {
|
|
"argument never used"
|
|
};
|
|
(cx.args[i].expr.span, msg)
|
|
})
|
|
.collect::<Vec<_>>();
|
|
|
|
let errs_len = errs.len();
|
|
if !errs.is_empty() {
|
|
let args_used = cx.arg_types.len() - errs_len;
|
|
let args_unused = errs_len;
|
|
|
|
let mut diag = {
|
|
if let [(sp, msg)] = &errs[..] {
|
|
let mut diag = cx.ecx.struct_span_err(*sp, *msg);
|
|
diag.span_label(*sp, *msg);
|
|
diag
|
|
} else {
|
|
let mut diag = cx.ecx.struct_span_err(
|
|
errs.iter().map(|&(sp, _)| sp).collect::<Vec<Span>>(),
|
|
"multiple unused formatting arguments",
|
|
);
|
|
diag.span_label(cx.fmtsp, "multiple missing formatting specifiers");
|
|
for (sp, msg) in errs {
|
|
diag.span_label(sp, msg);
|
|
}
|
|
diag
|
|
}
|
|
};
|
|
|
|
// Used to ensure we only report translations for *one* kind of foreign format.
|
|
let mut found_foreign = false;
|
|
// Decide if we want to look for foreign formatting directives.
|
|
if args_used < args_unused {
|
|
use super::format_foreign as foreign;
|
|
|
|
// The set of foreign substitutions we've explained. This prevents spamming the user
|
|
// with `%d should be written as {}` over and over again.
|
|
let mut explained = FxHashSet::default();
|
|
|
|
macro_rules! check_foreign {
|
|
($kind:ident) => {{
|
|
let mut show_doc_note = false;
|
|
|
|
let mut suggestions = vec![];
|
|
// account for `"` and account for raw strings `r#`
|
|
let padding = str_style.map(|i| i + 2).unwrap_or(1);
|
|
for sub in foreign::$kind::iter_subs(fmt_str, padding) {
|
|
let (trn, success) = match sub.translate() {
|
|
Ok(trn) => (trn, true),
|
|
Err(Some(msg)) => (msg, false),
|
|
|
|
// If it has no translation, don't call it out specifically.
|
|
_ => continue,
|
|
};
|
|
|
|
let pos = sub.position();
|
|
let sub = String::from(sub.as_str());
|
|
if explained.contains(&sub) {
|
|
continue;
|
|
}
|
|
explained.insert(sub.clone());
|
|
|
|
if !found_foreign {
|
|
found_foreign = true;
|
|
show_doc_note = true;
|
|
}
|
|
|
|
if let Some(inner_sp) = pos {
|
|
let sp = fmt_sp.from_inner(inner_sp);
|
|
|
|
if success {
|
|
suggestions.push((sp, trn));
|
|
} else {
|
|
diag.span_note(
|
|
sp,
|
|
&format!("format specifiers use curly braces, and {}", trn),
|
|
);
|
|
}
|
|
} else {
|
|
if success {
|
|
diag.help(&format!("`{}` should be written as `{}`", sub, trn));
|
|
} else {
|
|
diag.note(&format!(
|
|
"`{}` should use curly braces, and {}",
|
|
sub, trn
|
|
));
|
|
}
|
|
}
|
|
}
|
|
|
|
if show_doc_note {
|
|
diag.note(concat!(
|
|
stringify!($kind),
|
|
" formatting not supported; see the documentation for `std::fmt`",
|
|
));
|
|
}
|
|
if suggestions.len() > 0 {
|
|
diag.multipart_suggestion(
|
|
"format specifiers use curly braces",
|
|
suggestions,
|
|
Applicability::MachineApplicable,
|
|
);
|
|
}
|
|
}};
|
|
}
|
|
|
|
check_foreign!(printf);
|
|
if !found_foreign {
|
|
check_foreign!(shell);
|
|
}
|
|
}
|
|
if !found_foreign && errs_len == 1 {
|
|
diag.span_label(cx.fmtsp, "formatting specifier missing");
|
|
}
|
|
|
|
diag.emit();
|
|
} else if cx.invalid_refs.is_empty() && cx.ecx.sess.err_count() == 0 {
|
|
// Only check for unused named argument names if there are no other errors to avoid causing
|
|
// too much noise in output errors, such as when a named argument is entirely unused.
|
|
create_lints_for_named_arguments_used_positionally(&mut cx);
|
|
}
|
|
|
|
cx.into_expr()
|
|
}
|
|
|
|
fn may_contain_yield_point(e: &ast::Expr) -> bool {
|
|
struct MayContainYieldPoint(bool);
|
|
|
|
impl Visitor<'_> for MayContainYieldPoint {
|
|
fn visit_expr(&mut self, e: &ast::Expr) {
|
|
if let ast::ExprKind::Await(_) | ast::ExprKind::Yield(_) = e.kind {
|
|
self.0 = true;
|
|
} else {
|
|
visit::walk_expr(self, e);
|
|
}
|
|
}
|
|
|
|
fn visit_mac_call(&mut self, _: &ast::MacCall) {
|
|
self.0 = true;
|
|
}
|
|
|
|
fn visit_attribute(&mut self, _: &ast::Attribute) {
|
|
// Conservatively assume this may be a proc macro attribute in
|
|
// expression position.
|
|
self.0 = true;
|
|
}
|
|
|
|
fn visit_item(&mut self, _: &ast::Item) {
|
|
// Do not recurse into nested items.
|
|
}
|
|
}
|
|
|
|
let mut visitor = MayContainYieldPoint(false);
|
|
visitor.visit_expr(e);
|
|
visitor.0
|
|
}
|