//! Format attributes and meta items.
+use comment::{contains_comment, rewrite_doc_comment, CommentStyle};
use config::lists::*;
-use syntax::ast;
-use syntax::codemap::Span;
-
-use comment::{combine_strs_with_missing_comments, contains_comment, rewrite_doc_comment};
+use config::IndentStyle;
use expr::rewrite_literal;
-use lists::{itemize_list, write_list, ListFormatting};
+use lists::{definitive_tactic, itemize_list, write_list, ListFormatting, Separator};
+use overflow;
use rewrite::{Rewrite, RewriteContext};
use shape::Shape;
+use types::{rewrite_path, PathContext};
use utils::{count_newlines, mk_sp};
+use syntax::ast;
+use syntax::source_map::{BytePos, Span, DUMMY_SP};
+
/// Returns attributes on the given statement.
pub fn get_attrs_from_stmt(stmt: &ast::Stmt) -> &[ast::Attribute] {
match stmt.node {
}
/// Returns the arguments of `#[derive(...)]`.
-fn get_derive_args<'a>(context: &'a RewriteContext, attr: &ast::Attribute) -> Option<Vec<&'a str>> {
+fn get_derive_spans(attr: &ast::Attribute) -> Option<Vec<Span>> {
attr.meta_item_list().map(|meta_item_list| {
meta_item_list
.iter()
- .map(|nested_meta_item| context.snippet(nested_meta_item.span))
+ .map(|nested_meta_item| nested_meta_item.span)
.collect()
})
}
-// Format `#[derive(..)]`, using visual indent & mixed style when we need to go multiline.
-fn format_derive(context: &RewriteContext, derive_args: &[&str], shape: Shape) -> Option<String> {
- let mut result = String::with_capacity(128);
- result.push_str("#[derive(");
- // 11 = `#[derive()]`
- let initial_budget = shape.width.checked_sub(11)?;
- let mut budget = initial_budget;
- let num = derive_args.len();
- for (i, a) in derive_args.iter().enumerate() {
- // 2 = `, ` or `)]`
- let width = a.len() + 2;
- if width > budget {
- if i > 0 {
- // Remove trailing whitespace.
- result.pop();
+// The shape of the arguments to a function-like attribute.
+fn argument_shape(
+ left: usize,
+ right: usize,
+ combine: bool,
+ shape: Shape,
+ context: &RewriteContext,
+) -> Option<Shape> {
+ match context.config.indent_style() {
+ IndentStyle::Block => {
+ if combine {
+ shape.offset_left(left)
+ } else {
+ Some(
+ shape
+ .block_indent(context.config.tab_spaces())
+ .with_max_width(context.config),
+ )
}
- result.push('\n');
- // 9 = `#[derive(`
- result.push_str(&(shape.indent + 9).to_string(context.config));
- budget = initial_budget;
- } else {
- budget = budget.checked_sub(width).unwrap_or(0);
- }
- result.push_str(a);
- if i != num - 1 {
- result.push_str(", ")
}
+ IndentStyle::Visual => shape
+ .visual_indent(0)
+ .shrink_left(left)
+ .and_then(|s| s.sub_width(right)),
+ }
+}
+
+fn format_derive(
+ derive_args: &[Span],
+ prefix: &str,
+ shape: Shape,
+ context: &RewriteContext,
+) -> Option<String> {
+ let mut result = String::with_capacity(128);
+ result.push_str(prefix);
+ result.push_str("[derive(");
+
+ let argument_shape = argument_shape(10 + prefix.len(), 2, false, shape, context)?;
+ let item_str = format_arg_list(
+ derive_args.iter(),
+ |_| DUMMY_SP.lo(),
+ |_| DUMMY_SP.hi(),
+ |sp| Some(context.snippet(**sp).to_owned()),
+ DUMMY_SP,
+ context,
+ argument_shape,
+ // 10 = "[derive()]", 3 = "()" and "]"
+ shape.offset_left(10 + prefix.len())?.sub_width(3)?,
+ None,
+ false,
+ )?;
+
+ result.push_str(&item_str);
+ if item_str.starts_with('\n') {
+ result.push(',');
+ result.push_str(&shape.indent.to_string_with_newline(context.config));
}
result.push_str(")]");
Some(result)
&attrs[..len]
}
-/// Rewrite the same kind of attributes at the same time. This includes doc
-/// comments and derives.
-fn rewrite_first_group_attrs(
+/// Rewrite the any doc comments which come before any other attributes.
+fn rewrite_initial_doc_comments(
context: &RewriteContext,
attrs: &[ast::Attribute],
shape: Shape,
-) -> Option<(usize, String)> {
+) -> Option<(usize, Option<String>)> {
if attrs.is_empty() {
- return Some((0, String::new()));
+ return Some((0, None));
}
// Rewrite doc comments
let sugared_docs = take_while_with_pred(context, attrs, |a| a.is_sugared_doc);
.join("\n");
return Some((
sugared_docs.len(),
- rewrite_doc_comment(&snippet, shape.comment(context.config), context.config)?,
+ Some(rewrite_doc_comment(
+ &snippet,
+ shape.comment(context.config),
+ context.config,
+ )?),
));
}
- // Rewrite `#[derive(..)]`s.
- if context.config.merge_derives() {
- let derives = take_while_with_pred(context, attrs, is_derive);
- if !derives.is_empty() {
- let mut derive_args = vec![];
- for derive in derives {
- derive_args.append(&mut get_derive_args(context, derive)?);
- }
- return Some((derives.len(), format_derive(context, &derive_args, shape)?));
- }
- }
- // Rewrite the first attribute.
- Some((1, attrs[0].rewrite(context, shape)?))
+
+ Some((0, None))
}
impl Rewrite for ast::NestedMetaItem {
fn has_newlines_before_after_comment(comment: &str) -> (&str, &str) {
// Look at before and after comment and see if there are any empty lines.
- let comment_begin = comment.chars().position(|c| c == '/');
+ let comment_begin = comment.find('/');
let len = comment_begin.unwrap_or_else(|| comment.len());
let mlb = count_newlines(&comment[..len]) > 1;
let mla = if comment_begin.is_none() {
mlb
} else {
- let comment_end = comment.chars().rev().position(|c| !c.is_whitespace());
- let len = comment_end.unwrap();
comment
.chars()
.rev()
- .take(len)
- .filter(|c| *c == '\n')
- .count() > 1
+ .take_while(|c| c.is_whitespace())
+ .filter(|&c| c == '\n')
+ .count()
+ > 1
};
(if mlb { "\n" } else { "" }, if mla { "\n" } else { "" })
}
impl Rewrite for ast::MetaItem {
fn rewrite(&self, context: &RewriteContext, shape: Shape) -> Option<String> {
Some(match self.node {
- ast::MetaItemKind::Word => String::from(&*self.name.as_str()),
+ ast::MetaItemKind::Word => {
+ rewrite_path(context, PathContext::Type, None, &self.ident, shape)?
+ }
ast::MetaItemKind::List(ref list) => {
- let name = self.name.as_str();
- // 1 = `(`, 2 = `]` and `)`
- let item_shape = shape
- .visual_indent(0)
- .shrink_left(name.len() + 1)
- .and_then(|s| s.sub_width(2))?;
- let items = itemize_list(
- context.snippet_provider,
+ let path = rewrite_path(context, PathContext::Type, None, &self.ident, shape)?;
+ let has_trailing_comma = ::expr::span_ends_with_comma(context, self.span);
+ overflow::rewrite_with_parens(
+ context,
+ &path,
list.iter(),
- ")",
- ",",
- |nested_meta_item| nested_meta_item.span.lo(),
- |nested_meta_item| nested_meta_item.span.hi(),
- |nested_meta_item| nested_meta_item.rewrite(context, item_shape),
- self.span.lo(),
- self.span.hi(),
- false,
- );
- let item_vec = items.collect::<Vec<_>>();
- let fmt = ListFormatting {
- tactic: DefinitiveListTactic::Mixed,
- separator: ",",
- trailing_separator: SeparatorTactic::Never,
- separator_place: SeparatorPlace::Back,
- shape: item_shape,
- ends_with_newline: false,
- preserve_newline: false,
- config: context.config,
- };
- format!("{}({})", name, write_list(&item_vec, &fmt)?)
+ // 1 = "]"
+ shape.sub_width(1)?,
+ self.span,
+ context.config.width_heuristics().attr_fn_like_width,
+ Some(if has_trailing_comma {
+ SeparatorTactic::Always
+ } else {
+ SeparatorTactic::Never
+ }),
+ )?
}
ast::MetaItemKind::NameValue(ref literal) => {
- let name = self.name.as_str();
+ let path = rewrite_path(context, PathContext::Type, None, &self.ident, shape)?;
// 3 = ` = `
- let lit_shape = shape.shrink_left(name.len() + 3)?;
+ let lit_shape = shape.shrink_left(path.len() + 3)?;
// `rewrite_literal` returns `None` when `literal` exceeds max
// width. Since a literal is basically unformattable unless it
// is a string literal (and only if `format_strings` is set),
// See #2479 for example.
let value = rewrite_literal(context, literal, lit_shape)
.unwrap_or_else(|| context.snippet(literal.span).to_owned());
- format!("{} = {}", name, value)
+ format!("{} = {}", path, value)
}
})
}
}
+fn format_arg_list<I, T, F1, F2, F3>(
+ list: I,
+ get_lo: F1,
+ get_hi: F2,
+ get_item_string: F3,
+ span: Span,
+ context: &RewriteContext,
+ shape: Shape,
+ one_line_shape: Shape,
+ one_line_limit: Option<usize>,
+ combine: bool,
+) -> Option<String>
+where
+ I: Iterator<Item = T>,
+ F1: Fn(&T) -> BytePos,
+ F2: Fn(&T) -> BytePos,
+ F3: Fn(&T) -> Option<String>,
+{
+ let items = itemize_list(
+ context.snippet_provider,
+ list,
+ ")",
+ ",",
+ get_lo,
+ get_hi,
+ get_item_string,
+ span.lo(),
+ span.hi(),
+ false,
+ );
+ let item_vec = items.collect::<Vec<_>>();
+ let tactic = if let Some(limit) = one_line_limit {
+ ListTactic::LimitedHorizontalVertical(limit)
+ } else {
+ ListTactic::HorizontalVertical
+ };
+
+ let tactic = definitive_tactic(&item_vec, tactic, Separator::Comma, shape.width);
+ let fmt = ListFormatting::new(shape, context.config)
+ .tactic(tactic)
+ .ends_with_newline(false);
+ let item_str = write_list(&item_vec, &fmt)?;
+
+ let one_line_budget = one_line_shape.width;
+ if context.config.indent_style() == IndentStyle::Visual
+ || combine
+ || (!item_str.contains('\n') && item_str.len() <= one_line_budget)
+ {
+ Some(item_str)
+ } else {
+ let nested_indent = shape.indent.to_string_with_newline(context.config);
+ Some(format!("{}{}", nested_indent, item_str))
+ }
+}
+
impl Rewrite for ast::Attribute {
fn rewrite(&self, context: &RewriteContext, shape: Shape) -> Option<String> {
- let prefix = match self.style {
- ast::AttrStyle::Inner => "#!",
- ast::AttrStyle::Outer => "#",
- };
let snippet = context.snippet(self.span);
if self.is_sugared_doc {
rewrite_doc_comment(snippet, shape.comment(context.config), context.config)
} else {
+ let prefix = attr_prefix(self);
+
if contains_comment(snippet) {
return Some(snippet.to_owned());
}
- // 1 = `[`
- let shape = shape.offset_left(prefix.len() + 1)?;
- Some(
- self.meta()
- .and_then(|meta| meta.rewrite(context, shape))
- .map_or_else(|| snippet.to_owned(), |rw| format!("{}[{}]", prefix, rw)),
- )
+
+ if let Some(ref meta) = self.meta() {
+ // This attribute is possibly a doc attribute needing normalization to a doc comment
+ if context.config.normalize_doc_attributes() && meta.check_name("doc") {
+ if let Some(ref literal) = meta.value_str() {
+ let comment_style = match self.style {
+ ast::AttrStyle::Inner => CommentStyle::Doc,
+ ast::AttrStyle::Outer => CommentStyle::TripleSlash,
+ };
+
+ // Remove possible whitespace from the `CommentStyle::opener()` so that
+ // the literal itself has control over the comment's leading spaces.
+ let opener = comment_style.opener().trim_end();
+
+ let doc_comment = format!("{}{}", opener, literal);
+ return rewrite_doc_comment(
+ &doc_comment,
+ shape.comment(context.config),
+ context.config,
+ );
+ }
+ }
+
+ // 1 = `[`
+ let shape = shape.offset_left(prefix.len() + 1)?;
+ Some(
+ meta.rewrite(context, shape)
+ .map_or_else(|| snippet.to_owned(), |rw| format!("{}[{}]", prefix, rw)),
+ )
+ } else {
+ Some(snippet.to_owned())
+ }
}
}
}
if self.is_empty() {
return Some(String::new());
}
- let (first_group_len, first_group_str) = rewrite_first_group_attrs(context, self, shape)?;
- if self.len() == 1 || first_group_len == self.len() {
- Some(first_group_str)
- } else {
- let rest_str = self[first_group_len..].rewrite(context, shape)?;
- let missing_span = mk_sp(
- self[first_group_len - 1].span.hi(),
- self[first_group_len].span.lo(),
- );
- // Preserve an empty line before/after doc comments.
- if self[0].is_sugared_doc || self[first_group_len].is_sugared_doc {
- let snippet = context.snippet(missing_span);
- let (mla, mlb) = has_newlines_before_after_comment(snippet);
+
+ // The current remaining attributes.
+ let mut attrs = self;
+ let mut result = String::new();
+
+ // This is not just a simple map because we need to handle doc comments
+ // (where we take as many doc comment attributes as possible) and possibly
+ // merging derives into a single attribute.
+ loop {
+ if attrs.is_empty() {
+ return Some(result);
+ }
+
+ // Handle doc comments.
+ let (doc_comment_len, doc_comment_str) =
+ rewrite_initial_doc_comments(context, attrs, shape)?;
+ if doc_comment_len > 0 {
+ let doc_comment_str = doc_comment_str.expect("doc comments, but no result");
+ result.push_str(&doc_comment_str);
+
+ let missing_span = attrs
+ .get(doc_comment_len)
+ .map(|next| mk_sp(attrs[doc_comment_len - 1].span.hi(), next.span.lo()));
+ if let Some(missing_span) = missing_span {
+ let snippet = context.snippet(missing_span);
+ let (mla, mlb) = has_newlines_before_after_comment(snippet);
+ let comment = ::comment::recover_missing_comment_in_span(
+ missing_span,
+ shape.with_max_width(context.config),
+ context,
+ 0,
+ )?;
+ let comment = if comment.is_empty() {
+ format!("\n{}", mlb)
+ } else {
+ format!("{}{}\n{}", mla, comment, mlb)
+ };
+ result.push_str(&comment);
+ result.push_str(&shape.indent.to_string(context.config));
+ }
+
+ attrs = &attrs[doc_comment_len..];
+
+ continue;
+ }
+
+ // Handle derives if we will merge them.
+ if context.config.merge_derives() && is_derive(&attrs[0]) {
+ let derives = take_while_with_pred(context, attrs, is_derive);
+ let mut derive_spans = vec![];
+ for derive in derives {
+ derive_spans.append(&mut get_derive_spans(derive)?);
+ }
+ let derive_str =
+ format_derive(&derive_spans, attr_prefix(&attrs[0]), shape, context)?;
+ result.push_str(&derive_str);
+
+ let missing_span = attrs
+ .get(derives.len())
+ .map(|next| mk_sp(attrs[derives.len() - 1].span.hi(), next.span.lo()));
+ if let Some(missing_span) = missing_span {
+ let comment = ::comment::recover_missing_comment_in_span(
+ missing_span,
+ shape.with_max_width(context.config),
+ context,
+ 0,
+ )?;
+ result.push_str(&comment);
+ if let Some(next) = attrs.get(derives.len()) {
+ if next.is_sugared_doc {
+ let snippet = context.snippet(missing_span);
+ let (_, mlb) = has_newlines_before_after_comment(snippet);
+ result.push_str(&mlb);
+ }
+ }
+ result.push('\n');
+ result.push_str(&shape.indent.to_string(context.config));
+ }
+
+ attrs = &attrs[derives.len()..];
+
+ continue;
+ }
+
+ // If we get here, then we have a regular attribute, just handle one
+ // at a time.
+
+ let formatted_attr = attrs[0].rewrite(context, shape)?;
+ result.push_str(&formatted_attr);
+
+ let missing_span = attrs
+ .get(1)
+ .map(|next| mk_sp(attrs[0].span.hi(), next.span.lo()));
+ if let Some(missing_span) = missing_span {
let comment = ::comment::recover_missing_comment_in_span(
missing_span,
shape.with_max_width(context.config),
context,
0,
)?;
- let comment = if comment.is_empty() {
- format!("\n{}", mlb)
- } else {
- format!("{}{}\n{}", mla, comment, mlb)
- };
- Some(format!(
- "{}{}{}{}",
- first_group_str,
- comment,
- shape.indent.to_string(context.config),
- rest_str
- ))
- } else {
- combine_strs_with_missing_comments(
- context,
- &first_group_str,
- &rest_str,
- missing_span,
- shape,
- false,
- )
+ result.push_str(&comment);
+ if let Some(next) = attrs.get(1) {
+ if next.is_sugared_doc {
+ let snippet = context.snippet(missing_span);
+ let (_, mlb) = has_newlines_before_after_comment(snippet);
+ result.push_str(&mlb);
+ }
+ }
+ result.push('\n');
+ result.push_str(&shape.indent.to_string(context.config));
}
+
+ attrs = &attrs[1..];
}
}
}
+
+fn attr_prefix(attr: &ast::Attribute) -> &'static str {
+ match attr.style {
+ ast::AttrStyle::Inner => "#!",
+ ast::AttrStyle::Outer => "#",
+ }
+}
projects / rust.git / blobdiff