Avoid overlapping spans by only pointing at the arguments that are not
being used in the argument string. Enable libsyntax to have diagnostics
with multiple primary spans by accepting `Into<MultiSpan>` instead of
`Span`.
Replaced by adding extra imports, adding hidden code (`# ...`), modifying
examples to be runnable (sorry Homura), specifying non-Rust code, and
converting to should_panic, no_run, or compile_fail.
Remaining "```ignore"s received an explanation why they are being ignored.
On fmt string with unescaped `{` note how to escape
On cases of malformed format strings where a `{` hasn't been properly escaped, like `println!("{");`, present a NOTE explaining how to escape the `{` char.
Fix#34300.
On cases of malformed format strings where a `{` hasn't been properly
escaped, like `println!("{");`, present a note explaining how to escape
the `{` char.
This teaches `format_args!` how to interpret format printf- and
shell-style format directives. This is used in cases where there are
unused formatting arguments, and the reason for that *might* be because
the programmer is trying to use the wrong kind of formatting string.
This was prompted by an issue encountered by simulacrum on the #rust IRC
channel. In short: although `println!` told them that they weren't using
all of the conversion arguments, the problem was in using printf-syle
directives rather than ones `println!` would undertand.
Where possible, `format_args!` will tell the programmer what they should
use instead. For example, it will suggest replacing `%05d` with `{:0>5}`,
or `%2$.*3$s` with `{1:.3$}`. Even if it cannot suggest a replacement,
it will explicitly note that Rust does not support that style of directive,
and direct the user to the `std::fmt` documentation.
This applies the HIR changes from the previous commits to the AST, and
is thus a syntax-[breaking-change]
Renames `PatKind::Vec` to `PatKind::Slice`, since these are called slice
patterns, not vec patterns. Renames `TyKind::Vec`, which represents the
type `[T]`, to `TyKind::Slice`. Renames `TyKind::FixedLengthVec` to
`TyKind::Array`.
This commit removed the restriction of only allowing one type per argument.
This is achieved by adding mappings between macro arguments and format
placeholders, then taking the mapping into consideration when emitting
the Arguments expression.
syntax_ext: format: fix implicit positional arguments
syntax_ext: format: don't panic if no args given for implicit positional args
Check the list lengths before use.
Fixes regression of `compile-fail/macro-backtrace-println.rs`.
syntax_ext: format: also map CountIsParam indices to expanded args
syntax_ext: format: fix ICE in case of malformed format args
Converts named argument references into indices, right after
verification as suggested by @alexcrichton. This drastically simplifies
the whole process!
format: beautifully get rid of ArgumentNext and CountIsNextParam
Now that CountIsNextParam and ArgumentNext are resolved during parse,
the need for handling them outside of libfmt_macros is obviated.
Note: *one* instance of implicit reference handling still remains, and
that's for implementing `all_args_simple`. It's trivial enough though,
so in this case it may be tolerable.
This is a spiritual succesor to #34268/8531d581, in which we replaced a
number of matches of None to the unit value with `if let` conditionals
where it was judged that this made for clearer/simpler code (as would be
recommended by Manishearth/rust-clippy's `single_match` lint). The same
rationale applies to matches of None to the empty block.
To allow these braced macro invocation, this PR removes the optional expression from `ast::Block` and instead uses a `StmtKind::Expr` at the end of the statement list.
Currently, braced macro invocations in blocks can expand into statements (and items) except when they are last in a block, in which case they can only expand into expressions.
For example,
```rust
macro_rules! make_stmt {
() => { let x = 0; }
}
fn f() {
make_stmt! {} //< This is OK...
let x = 0; //< ... unless this line is commented out.
}
```
Fixes#34418.
syntax-[breaking-change] cc #31645
(Only breaking because ast::TokenTree is now tokenstream::TokenTree.)
This pull request refactors TokenTrees into their own file as src/libsyntax/tokenstream.rs, moving them out of src/libsyntax/ast.rs, in order to prepare for an accompanying TokenStream implementation (per RFC 1566).
