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Rollup merge of rust-lang#61568 - Mark-Simulacrum:symbol-fmt-macros, …
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…r=estebank

Use Symbol, Span in libfmt_macros

I'm not super happy with this, personally, but I think it might be a decent start -- happy to take suggestions as to how to expand this or change things further.

r? @estebank

Fixes rust-lang#60795
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@Centril
Centril authored Jun 12, 2019
2 parents b5184e5 + 45df52f commit d78260d
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Showing 11 changed files with 175 additions and 151 deletions.
3 changes: 3 additions & 0 deletions Cargo.lock
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Original file line number Diff line number Diff line change
Expand Up @@ -910,6 +910,9 @@ dependencies = [
[[package]]
name = "fmt_macros"
version = "0.0.0"
dependencies = [
"syntax_pos 0.0.0",
]

[[package]]
name = "fnv"
Expand Down
3 changes: 3 additions & 0 deletions src/libfmt_macros/Cargo.toml
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Original file line number Diff line number Diff line change
Expand Up @@ -8,3 +8,6 @@ edition = "2018"
name = "fmt_macros"
path = "lib.rs"
crate-type = ["dylib"]

[dependencies]
syntax_pos = { path = "../libsyntax_pos" }
133 changes: 67 additions & 66 deletions src/libfmt_macros/lib.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -25,6 +25,17 @@ use std::str;
use std::string;
use std::iter;

use syntax_pos::{InnerSpan, Symbol};

#[derive(Copy, Clone)]
struct InnerOffset(usize);

impl InnerOffset {
fn to(self, end: InnerOffset) -> InnerSpan {
InnerSpan::new(self.0, end.0)
}
}

/// A piece is a portion of the format string which represents the next part
/// to emit. These are emitted as a stream by the `Parser` class.
#[derive(Copy, Clone, PartialEq)]
Expand All @@ -40,7 +51,7 @@ pub enum Piece<'a> {
#[derive(Copy, Clone, PartialEq)]
pub struct Argument<'a> {
/// Where to find this argument
pub position: Position<'a>,
pub position: Position,
/// How to format the argument
pub format: FormatSpec<'a>,
}
Expand All @@ -55,9 +66,9 @@ pub struct FormatSpec<'a> {
/// Packed version of various flags provided
pub flags: u32,
/// The integer precision to use
pub precision: Count<'a>,
pub precision: Count,
/// The string width requested for the resulting format
pub width: Count<'a>,
pub width: Count,
/// The descriptor string representing the name of the format desired for
/// this argument, this can be empty or any number of characters, although
/// it is required to be one word.
Expand All @@ -66,16 +77,16 @@ pub struct FormatSpec<'a> {

/// Enum describing where an argument for a format can be located.
#[derive(Copy, Clone, PartialEq)]
pub enum Position<'a> {
pub enum Position {
/// The argument is implied to be located at an index
ArgumentImplicitlyIs(usize),
/// The argument is located at a specific index given in the format
ArgumentIs(usize),
/// The argument has a name.
ArgumentNamed(&'a str),
ArgumentNamed(Symbol),
}

impl Position<'_> {
impl Position {
pub fn index(&self) -> Option<usize> {
match self {
ArgumentIs(i) | ArgumentImplicitlyIs(i) => Some(*i),
Expand Down Expand Up @@ -120,11 +131,11 @@ pub enum Flag {
/// A count is used for the precision and width parameters of an integer, and
/// can reference either an argument or a literal integer.
#[derive(Copy, Clone, PartialEq)]
pub enum Count<'a> {
pub enum Count {
/// The count is specified explicitly.
CountIs(usize),
/// The count is specified by the argument with the given name.
CountIsName(&'a str),
CountIsName(Symbol),
/// The count is specified by the argument at the given index.
CountIsParam(usize),
/// The count is implied and cannot be explicitly specified.
Expand All @@ -135,9 +146,8 @@ pub struct ParseError {
pub description: string::String,
pub note: Option<string::String>,
pub label: string::String,
pub start: SpanIndex,
pub end: SpanIndex,
pub secondary_label: Option<(string::String, SpanIndex, SpanIndex)>,
pub span: InnerSpan,
pub secondary_label: Option<(string::String, InnerSpan)>,
}

/// The parser structure for interpreting the input format string. This is
Expand All @@ -156,44 +166,36 @@ pub struct Parser<'a> {
/// `Some(raw count)` when the string is "raw", used to position spans correctly
style: Option<usize>,
/// Start and end byte offset of every successfully parsed argument
pub arg_places: Vec<(SpanIndex, SpanIndex)>,
pub arg_places: Vec<InnerSpan>,
/// Characters that need to be shifted
skips: Vec<usize>,
/// Span offset of the last opening brace seen, used for error reporting
last_opening_brace_pos: Option<SpanIndex>,
/// Span of the last opening brace seen, used for error reporting
last_opening_brace: Option<InnerSpan>,
/// Wether the source string is comes from `println!` as opposed to `format!` or `print!`
append_newline: bool,
}

#[derive(Clone, Copy, Debug)]
pub struct SpanIndex(pub usize);

impl SpanIndex {
pub fn unwrap(self) -> usize {
self.0
}
}

impl<'a> Iterator for Parser<'a> {
type Item = Piece<'a>;

fn next(&mut self) -> Option<Piece<'a>> {
if let Some(&(pos, c)) = self.cur.peek() {
match c {
'{' => {
let curr_last_brace = self.last_opening_brace_pos;
self.last_opening_brace_pos = Some(self.to_span_index(pos));
let curr_last_brace = self.last_opening_brace;
let byte_pos = self.to_span_index(pos);
self.last_opening_brace = Some(byte_pos.to(InnerOffset(byte_pos.0 + 1)));
self.cur.next();
if self.consume('{') {
self.last_opening_brace_pos = curr_last_brace;
self.last_opening_brace = curr_last_brace;

Some(String(self.string(pos + 1)))
} else {
let arg = self.argument();
if let Some(arg_pos) = self.must_consume('}').map(|end| {
(self.to_span_index(pos), self.to_span_index(end + 1))
}) {
self.arg_places.push(arg_pos);
if let Some(end) = self.must_consume('}') {
let start = self.to_span_index(pos);
let end = self.to_span_index(end + 1);
self.arg_places.push(start.to(end));
}
Some(NextArgument(arg))
}
Expand All @@ -208,8 +210,7 @@ impl<'a> Iterator for Parser<'a> {
"unmatched `}` found",
"unmatched `}`",
"if you intended to print `}`, you can escape it using `}}`",
err_pos,
err_pos,
err_pos.to(err_pos),
);
None
}
Expand Down Expand Up @@ -241,7 +242,7 @@ impl<'a> Parser<'a> {
style,
arg_places: vec![],
skips,
last_opening_brace_pos: None,
last_opening_brace: None,
append_newline,
}
}
Expand All @@ -253,15 +254,13 @@ impl<'a> Parser<'a> {
&mut self,
description: S1,
label: S2,
start: SpanIndex,
end: SpanIndex,
span: InnerSpan,
) {
self.errors.push(ParseError {
description: description.into(),
note: None,
label: label.into(),
start,
end,
span,
secondary_label: None,
});
}
Expand All @@ -274,15 +273,13 @@ impl<'a> Parser<'a> {
description: S1,
label: S2,
note: S3,
start: SpanIndex,
end: SpanIndex,
span: InnerSpan,
) {
self.errors.push(ParseError {
description: description.into(),
note: Some(note.into()),
label: label.into(),
start,
end,
span,
secondary_label: None,
});
}
Expand All @@ -303,22 +300,21 @@ impl<'a> Parser<'a> {
}
}

fn raw(&self) -> usize {
self.style.map(|raw| raw + 1).unwrap_or(0)
}

fn to_span_index(&self, pos: usize) -> SpanIndex {
fn to_span_index(&self, pos: usize) -> InnerOffset {
let mut pos = pos;
// This handles the raw string case, the raw argument is the number of #
// in r###"..."### (we need to add one because of the `r`).
let raw = self.style.map(|raw| raw + 1).unwrap_or(0);
for skip in &self.skips {
if pos > *skip {
pos += 1;
} else if pos == *skip && self.raw() == 0 {
} else if pos == *skip && raw == 0 {
pos += 1;
} else {
break;
}
}
SpanIndex(self.raw() + pos + 1)
InnerOffset(raw + pos + 1)
}

/// Forces consumption of the specified character. If the character is not
Expand All @@ -336,8 +332,8 @@ impl<'a> Parser<'a> {
let label = "expected `}`".to_owned();
let (note, secondary_label) = if c == '}' {
(Some("if you intended to print `{`, you can escape it using `{{`".to_owned()),
self.last_opening_brace_pos.map(|pos| {
("because of this opening brace".to_owned(), pos, pos)
self.last_opening_brace.map(|sp| {
("because of this opening brace".to_owned(), sp)
}))
} else {
(None, None)
Expand All @@ -346,8 +342,7 @@ impl<'a> Parser<'a> {
description,
note,
label,
start: pos,
end: pos,
span: pos.to(pos),
secondary_label,
});
None
Expand All @@ -361,8 +356,8 @@ impl<'a> Parser<'a> {
let label = format!("expected `{:?}`", c);
let (note, secondary_label) = if c == '}' {
(Some("if you intended to print `{`, you can escape it using `{{`".to_owned()),
self.last_opening_brace_pos.map(|pos| {
("because of this opening brace".to_owned(), pos, pos)
self.last_opening_brace.map(|sp| {
("because of this opening brace".to_owned(), sp)
}))
} else {
(None, None)
Expand All @@ -371,12 +366,11 @@ impl<'a> Parser<'a> {
description,
note,
label,
start: pos,
end: pos,
span: pos.to(pos),
secondary_label,
});
} else {
self.err(description, format!("expected `{:?}`", c), pos, pos);
self.err(description, format!("expected `{:?}`", c), pos.to(pos));
}
None
}
Expand Down Expand Up @@ -435,20 +429,24 @@ impl<'a> Parser<'a> {
/// integer index of an argument, a named argument, or a blank string.
/// Returns `Some(parsed_position)` if the position is not implicitly
/// consuming a macro argument, `None` if it's the case.
fn position(&mut self) -> Option<Position<'a>> {
fn position(&mut self) -> Option<Position> {
if let Some(i) = self.integer() {
Some(ArgumentIs(i))
} else {
match self.cur.peek() {
Some(&(_, c)) if c.is_alphabetic() => Some(ArgumentNamed(self.word())),
Some(&(_, c)) if c.is_alphabetic() => {
Some(ArgumentNamed(Symbol::intern(self.word())))
}
Some(&(pos, c)) if c == '_' => {
let invalid_name = self.string(pos);
self.err_with_note(format!("invalid argument name `{}`", invalid_name),
"invalid argument name",
"argument names cannot start with an underscore",
self.to_span_index(pos),
self.to_span_index(pos + invalid_name.len()));
Some(ArgumentNamed(invalid_name))
self.to_span_index(pos).to(
self.to_span_index(pos + invalid_name.len())
),
);
Some(ArgumentNamed(Symbol::intern(invalid_name)))
},

// This is an `ArgumentNext`.
Expand Down Expand Up @@ -556,7 +554,7 @@ impl<'a> Parser<'a> {
/// Parses a Count parameter at the current position. This does not check
/// for 'CountIsNextParam' because that is only used in precision, not
/// width.
fn count(&mut self) -> Count<'a> {
fn count(&mut self) -> Count {
if let Some(i) = self.integer() {
if self.consume('$') {
CountIsParam(i)
Expand All @@ -570,7 +568,7 @@ impl<'a> Parser<'a> {
self.cur = tmp;
CountImplied
} else if self.consume('$') {
CountIsName(word)
CountIsName(Symbol::intern(word))
} else {
self.cur = tmp;
CountImplied
Expand Down Expand Up @@ -760,6 +758,8 @@ mod tests {
}
#[test]
fn format_counts() {
use syntax_pos::{GLOBALS, Globals, edition};
GLOBALS.set(&Globals::new(edition::DEFAULT_EDITION), || {
same("{:10s}",
&[NextArgument(Argument {
position: ArgumentImplicitlyIs(0),
Expand Down Expand Up @@ -815,11 +815,12 @@ mod tests {
fill: None,
align: AlignUnknown,
flags: 0,
precision: CountIsName("b"),
width: CountIsName("a"),
precision: CountIsName(Symbol::intern("b")),
width: CountIsName(Symbol::intern("a")),
ty: "s",
},
})]);
});
}
#[test]
fn format_flags() {
Expand Down
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