// and those with brackets will be formatted as array literals.
use std::collections::HashMap;
-use syntax::ast;
-use syntax::codemap::{BytePos, Span};
+
+use config::lists::*;
use syntax::parse::new_parser_from_tts;
use syntax::parse::parser::Parser;
use syntax::parse::token::{BinOpToken, DelimToken, Token};
use syntax::print::pprust;
+use syntax::source_map::{BytePos, Span};
use syntax::symbol;
use syntax::tokenstream::{Cursor, ThinTokenStream, TokenStream, TokenTree};
-use syntax::util::ThinVec;
+use syntax::ThinVec;
+use syntax::{ast, parse, ptr};
-use codemap::SpanUtils;
-use comment::{contains_comment, remove_trailing_white_spaces, FindUncommented};
-use expr::{rewrite_array, rewrite_call_inner};
-use lists::{itemize_list, write_list, DefinitiveListTactic, ListFormatting, SeparatorPlace, SeparatorTactic};
+use comment::{contains_comment, CharClasses, FindUncommented, FullCodeCharKind, LineClasses};
+use expr::rewrite_array;
+use lists::{itemize_list, write_list, ListFormatting};
+use overflow;
use rewrite::{Rewrite, RewriteContext};
use shape::{Indent, Shape};
-use utils::{format_visibility, mk_sp};
+use source_map::SpanUtils;
+use spanned::Spanned;
+use utils::{
+ format_visibility, is_empty_line, mk_sp, remove_trailing_white_spaces, rewrite_ident,
+ trim_left_preserve_layout, wrap_str, NodeIdExt,
+};
+use visitor::FmtVisitor;
const FORCED_BRACKET_MACROS: &[&str] = &["vec!"];
-// FIXME: use the enum from libsyntax?
-#[derive(Clone, Copy, PartialEq, Eq, Debug)]
-enum MacroStyle {
- Parens,
- Brackets,
- Braces,
-}
-
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum MacroPosition {
Item,
Pat,
}
-impl MacroStyle {
- fn opener(&self) -> &'static str {
- match *self {
- MacroStyle::Parens => "(",
- MacroStyle::Brackets => "[",
- MacroStyle::Braces => "{",
+#[derive(Debug)]
+pub enum MacroArg {
+ Expr(ptr::P<ast::Expr>),
+ Ty(ptr::P<ast::Ty>),
+ Pat(ptr::P<ast::Pat>),
+ Item(ptr::P<ast::Item>),
+}
+
+impl MacroArg {
+ fn is_item(&self) -> bool {
+ match self {
+ MacroArg::Item(..) => true,
+ _ => false,
}
}
}
-#[derive(Debug)]
-pub enum MacroArg {
- Expr(ast::Expr),
- Ty(ast::Ty),
- Pat(ast::Pat),
+impl Rewrite for ast::Item {
+ fn rewrite(&self, context: &RewriteContext, shape: Shape) -> Option<String> {
+ let mut visitor = ::visitor::FmtVisitor::from_context(context);
+ visitor.block_indent = shape.indent;
+ visitor.last_pos = self.span().lo();
+ visitor.visit_item(self);
+ Some(visitor.buffer.to_owned())
+ }
}
impl Rewrite for MacroArg {
MacroArg::Expr(ref expr) => expr.rewrite(context, shape),
MacroArg::Ty(ref ty) => ty.rewrite(context, shape),
MacroArg::Pat(ref pat) => pat.rewrite(context, shape),
+ MacroArg::Item(ref item) => item.rewrite(context, shape),
}
}
}
-fn parse_macro_arg(parser: &mut Parser) -> Option<MacroArg> {
+fn parse_macro_arg<'a, 'b: 'a>(parser: &'a mut Parser<'b>) -> Option<MacroArg> {
macro_rules! parse_macro_arg {
- ($macro_arg: ident, $parser: ident) => {
+ ($macro_arg:ident, $parser:expr, $f:expr) => {
let mut cloned_parser = (*parser).clone();
- match cloned_parser.$parser() {
+ match $parser(&mut cloned_parser) {
Ok(x) => {
if parser.sess.span_diagnostic.has_errors() {
parser.sess.span_diagnostic.reset_err_count();
} else {
// Parsing succeeded.
*parser = cloned_parser;
- return Some(MacroArg::$macro_arg((*x).clone()));
+ return Some(MacroArg::$macro_arg($f(x)?));
}
}
Err(mut e) => {
parser.sess.span_diagnostic.reset_err_count();
}
}
- }
+ };
}
- parse_macro_arg!(Expr, parse_expr);
- parse_macro_arg!(Ty, parse_ty);
- parse_macro_arg!(Pat, parse_pat);
+ parse_macro_arg!(
+ Expr,
+ |parser: &mut parse::parser::Parser<'b>| parser.parse_expr(),
+ |x: ptr::P<ast::Expr>| Some(x)
+ );
+ parse_macro_arg!(
+ Ty,
+ |parser: &mut parse::parser::Parser<'b>| parser.parse_ty(),
+ |x: ptr::P<ast::Ty>| Some(x)
+ );
+ parse_macro_arg!(
+ Pat,
+ |parser: &mut parse::parser::Parser<'b>| parser.parse_pat(None),
+ |x: ptr::P<ast::Pat>| Some(x)
+ );
+ // `parse_item` returns `Option<ptr::P<ast::Item>>`.
+ parse_macro_arg!(
+ Item,
+ |parser: &mut parse::parser::Parser<'b>| parser.parse_item(),
+ |x: Option<ptr::P<ast::Item>>| x
+ );
None
}
+/// Rewrite macro name without using pretty-printer if possible.
+fn rewrite_macro_name(
+ context: &RewriteContext,
+ path: &ast::Path,
+ extra_ident: Option<ast::Ident>,
+) -> String {
+ let name = if path.segments.len() == 1 {
+ // Avoid using pretty-printer in the common case.
+ format!("{}!", rewrite_ident(context, path.segments[0].ident))
+ } else {
+ format!("{}!", path)
+ };
+ match extra_ident {
+ Some(ident) if ident != symbol::keywords::Invalid.ident() => format!("{} {}", name, ident),
+ _ => name,
+ }
+}
+
+// Use this on failing to format the macro call.
+fn return_macro_parse_failure_fallback(
+ context: &RewriteContext,
+ indent: Indent,
+ span: Span,
+) -> Option<String> {
+ // Mark this as a failure however we format it
+ context.macro_rewrite_failure.replace(true);
+
+ // Heuristically determine whether the last line of the macro uses "Block" style
+ // rather than using "Visual" style, or another indentation style.
+ let is_like_block_indent_style = context
+ .snippet(span)
+ .lines()
+ .last()
+ .map(|closing_line| {
+ closing_line.trim().chars().all(|ch| match ch {
+ '}' | ')' | ']' => true,
+ _ => false,
+ })
+ })
+ .unwrap_or(false);
+ if is_like_block_indent_style {
+ return trim_left_preserve_layout(context.snippet(span), indent, &context.config);
+ }
+
+ // Return the snippet unmodified if the macro is not block-like
+ Some(context.snippet(span).to_owned())
+}
+
+struct InsideMacroGuard<'a> {
+ context: &'a RewriteContext<'a>,
+ is_nested: bool,
+}
+
+impl<'a> InsideMacroGuard<'a> {
+ fn inside_macro_context(context: &'a RewriteContext) -> InsideMacroGuard<'a> {
+ let is_nested = context.inside_macro.replace(true);
+ InsideMacroGuard { context, is_nested }
+ }
+}
+
+impl<'a> Drop for InsideMacroGuard<'a> {
+ fn drop(&mut self) {
+ self.context.inside_macro.replace(self.is_nested);
+ }
+}
+
pub fn rewrite_macro(
mac: &ast::Mac,
extra_ident: Option<ast::Ident>,
shape: Shape,
position: MacroPosition,
) -> Option<String> {
- let context = &mut context.clone();
- context.inside_macro = true;
+ let guard = InsideMacroGuard::inside_macro_context(context);
+ let result = rewrite_macro_inner(mac, extra_ident, context, shape, position, guard.is_nested);
+ if result.is_none() {
+ context.macro_rewrite_failure.replace(true);
+ }
+ result
+}
+
+pub fn rewrite_macro_inner(
+ mac: &ast::Mac,
+ extra_ident: Option<ast::Ident>,
+ context: &RewriteContext,
+ shape: Shape,
+ position: MacroPosition,
+ is_nested_macro: bool,
+) -> Option<String> {
if context.config.use_try_shorthand() {
if let Some(expr) = convert_try_mac(mac, context) {
- context.inside_macro = false;
+ context.inside_macro.replace(false);
return expr.rewrite(context, shape);
}
}
let original_style = macro_style(mac, context);
- let macro_name = match extra_ident {
- None => format!("{}!", mac.node.path),
- Some(ident) => {
- if ident == symbol::keywords::Invalid.ident() {
- format!("{}!", mac.node.path)
- } else {
- format!("{}! {}", mac.node.path, ident)
- }
- }
- };
+ let macro_name = rewrite_macro_name(context, &mac.node.path, extra_ident);
- let style = if FORCED_BRACKET_MACROS.contains(&¯o_name[..]) {
- MacroStyle::Brackets
+ let style = if FORCED_BRACKET_MACROS.contains(&¯o_name[..]) && !is_nested_macro {
+ DelimToken::Bracket
} else {
original_style
};
let ts: TokenStream = mac.node.stream();
- if ts.is_empty() && !contains_comment(context.snippet(mac.span)) {
+ let has_comment = contains_comment(context.snippet(mac.span));
+ if ts.is_empty() && !has_comment {
return match style {
- MacroStyle::Parens if position == MacroPosition::Item => {
+ DelimToken::Paren if position == MacroPosition::Item => {
Some(format!("{}();", macro_name))
}
- MacroStyle::Parens => Some(format!("{}()", macro_name)),
- MacroStyle::Brackets => Some(format!("{}[]", macro_name)),
- MacroStyle::Braces => Some(format!("{}{{}}", macro_name)),
+ DelimToken::Paren => Some(format!("{}()", macro_name)),
+ DelimToken::Bracket => Some(format!("{}[]", macro_name)),
+ DelimToken::Brace => Some(format!("{} {{}}", macro_name)),
+ _ => unreachable!(),
};
}
+ // Format well-known macros which cannot be parsed as a valid AST.
+ if macro_name == "lazy_static!" && !has_comment {
+ if let success @ Some(..) = format_lazy_static(context, shape, &ts) {
+ return success;
+ }
+ }
let mut parser = new_parser_from_tts(context.parse_session, ts.trees().collect());
let mut arg_vec = Vec::new();
let mut vec_with_semi = false;
let mut trailing_comma = false;
- if MacroStyle::Braces != style {
+ if DelimToken::Brace != style {
loop {
match parse_macro_arg(&mut parser) {
Some(arg) => arg_vec.push(arg),
- None => return Some(context.snippet(mac.span).to_owned()),
+ None => {
+ return return_macro_parse_failure_fallback(context, shape.indent, mac.span);
+ }
}
match parser.token {
break;
}
}
- None => return Some(context.snippet(mac.span).to_owned()),
+ None => {
+ return return_macro_parse_failure_fallback(
+ context,
+ shape.indent,
+ mac.span,
+ );
+ }
}
}
}
- return Some(context.snippet(mac.span).to_owned());
+ return return_macro_parse_failure_fallback(context, shape.indent, mac.span);
}
- _ => return Some(context.snippet(mac.span).to_owned()),
+ _ if arg_vec.last().map_or(false, MacroArg::is_item) => continue,
+ _ => return return_macro_parse_failure_fallback(context, shape.indent, mac.span),
}
parser.bump();
}
}
+ if !arg_vec.is_empty() && arg_vec.iter().all(MacroArg::is_item) {
+ return rewrite_macro_with_items(
+ context,
+ &arg_vec,
+ ¯o_name,
+ shape,
+ style,
+ position,
+ mac.span,
+ );
+ }
+
match style {
- MacroStyle::Parens => {
- // Format macro invocation as function call, forcing no trailing
+ DelimToken::Paren => {
+ // Format macro invocation as function call, preserve the trailing
// comma because not all macros support them.
- rewrite_call_inner(
+ overflow::rewrite_with_parens(
context,
¯o_name,
- &arg_vec.iter().map(|e| &*e).collect::<Vec<_>>()[..],
- mac.span,
+ arg_vec.iter(),
shape,
+ mac.span,
context.config.width_heuristics().fn_call_width,
- trailing_comma,
- ).map(|rw| match position {
+ if trailing_comma {
+ Some(SeparatorTactic::Always)
+ } else {
+ Some(SeparatorTactic::Never)
+ },
+ )
+ .map(|rw| match position {
MacroPosition::Item => format!("{};", rw),
_ => rw,
})
}
- MacroStyle::Brackets => {
- let mac_shape = shape.offset_left(macro_name.len())?;
+ DelimToken::Bracket => {
// Handle special case: `vec![expr; expr]`
if vec_with_semi {
- let (lbr, rbr) = if context.config.spaces_within_parens_and_brackets() {
- ("[ ", " ]")
- } else {
- ("[", "]")
- };
- // 6 = `vec!` + `; `
- let total_overhead = lbr.len() + rbr.len() + 6;
+ let mac_shape = shape.offset_left(macro_name.len())?;
+ // 8 = `vec![]` + `; `
+ let total_overhead = 8;
let nested_shape = mac_shape.block_indent(context.config.tab_spaces());
let lhs = arg_vec[0].rewrite(context, nested_shape)?;
let rhs = arg_vec[1].rewrite(context, nested_shape)?;
- if !lhs.contains('\n') && !rhs.contains('\n')
+ if !lhs.contains('\n')
+ && !rhs.contains('\n')
&& lhs.len() + rhs.len() + total_overhead <= shape.width
{
- Some(format!("{}{}{}; {}{}", macro_name, lbr, lhs, rhs, rbr))
+ Some(format!("{}[{}; {}]", macro_name, lhs, rhs))
} else {
Some(format!(
- "{}{}\n{}{};\n{}{}\n{}{}",
+ "{}[{}{};{}{}{}]",
macro_name,
- lbr,
- nested_shape.indent.to_string(context.config),
+ nested_shape.indent.to_string_with_newline(context.config),
lhs,
- nested_shape.indent.to_string(context.config),
+ nested_shape.indent.to_string_with_newline(context.config),
rhs,
- shape.indent.to_string(context.config),
- rbr
+ shape.indent.to_string_with_newline(context.config),
))
}
} else {
// If we are rewriting `vec!` macro or other special macros,
// then we can rewrite this as an usual array literal.
// Otherwise, we must preserve the original existence of trailing comma.
- if FORCED_BRACKET_MACROS.contains(¯o_name.as_str()) {
- context.inside_macro = false;
- trailing_comma = false;
+ let macro_name = ¯o_name.as_str();
+ let mut force_trailing_comma = if trailing_comma {
+ Some(SeparatorTactic::Always)
+ } else {
+ Some(SeparatorTactic::Never)
+ };
+ if FORCED_BRACKET_MACROS.contains(macro_name) && !is_nested_macro {
+ context.inside_macro.replace(false);
+ if context.use_block_indent() {
+ force_trailing_comma = Some(SeparatorTactic::Vertical);
+ };
}
- // Convert `MacroArg` into `ast::Expr`, as `rewrite_array` only accepts the latter.
- let sp = mk_sp(
- context
- .codemap
- .span_after(mac.span, original_style.opener()),
- mac.span.hi() - BytePos(1),
- );
- let arg_vec = &arg_vec.iter().map(|e| &*e).collect::<Vec<_>>()[..];
- let rewrite = rewrite_array(arg_vec, sp, context, mac_shape, trailing_comma)?;
-
- Some(format!("{}{}", macro_name, rewrite))
+ let rewrite = rewrite_array(
+ macro_name,
+ arg_vec.iter(),
+ mac.span,
+ context,
+ shape,
+ force_trailing_comma,
+ Some(original_style),
+ )?;
+ let comma = match position {
+ MacroPosition::Item => ";",
+ _ => "",
+ };
+
+ Some(format!("{}{}", rewrite, comma))
}
}
- MacroStyle::Braces => {
- // Skip macro invocations with braces, for now.
- indent_macro_snippet(context, context.snippet(mac.span), shape.indent)
+ DelimToken::Brace => {
+ // For macro invocations with braces, always put a space between
+ // the `macro_name!` and `{ /* macro_body */ }` but skip modifying
+ // anything in between the braces (for now).
+ let snippet = context.snippet(mac.span);
+ let macro_raw = snippet.split_at(snippet.find('!')? + 1).1.trim_start();
+ match trim_left_preserve_layout(macro_raw, shape.indent, &context.config) {
+ Some(macro_body) => Some(format!("{} {}", macro_name, macro_body)),
+ None => Some(format!("{} {}", macro_name, macro_raw)),
+ }
}
+ _ => unreachable!(),
}
}
span: Span,
) -> Option<String> {
let snippet = Some(remove_trailing_white_spaces(context.snippet(span)));
+ if snippet.as_ref().map_or(true, |s| s.ends_with(';')) {
+ return snippet;
+ }
let mut parser = MacroParser::new(def.stream().into_trees());
let parsed_def = match parser.parse() {
let mut result = if def.legacy {
String::from("macro_rules!")
} else {
- format!("{}macro", format_visibility(vis))
+ format!("{}macro", format_visibility(context, vis))
};
result += " ";
- result += &ident.name.as_str();
+ result += rewrite_ident(context, ident);
let multi_branch_style = def.legacy || parsed_def.branches.len() != 1;
- let mac_indent = if multi_branch_style {
- result += " {";
- indent.block_indent(context.config)
+ let arm_shape = if multi_branch_style {
+ shape
+ .block_indent(context.config.tab_spaces())
+ .with_max_width(context.config)
} else {
- indent
+ shape
};
- let mac_indent_str = mac_indent.to_string(context.config);
-
let branch_items = itemize_list(
- context.codemap,
+ context.snippet_provider,
parsed_def.branches.iter(),
- "",
- "",
- |branch| branch.args_span.lo(),
- |branch| branch.body.hi(),
- |branch| {
- let mut result = String::new();
-
- // Only attempt to format function-like macros.
- if branch.args_paren_kind != DelimToken::Paren {
- // FIXME(#1539): implement for non-sugared macros.
- return None;
- }
-
- let args = format_macro_args(branch.args.clone())?;
-
- if multi_branch_style {
- result += "\n";
- result += &mac_indent_str;
- result += &args;
- result += " =>";
- } else {
- result += &args;
+ "}",
+ ";",
+ |branch| branch.span.lo(),
+ |branch| branch.span.hi(),
+ |branch| match branch.rewrite(context, arm_shape, multi_branch_style) {
+ Some(v) => Some(v),
+ // if the rewrite returned None because a macro could not be rewritten, then return the
+ // original body
+ None if *context.macro_rewrite_failure.borrow() => {
+ Some(context.snippet(branch.body).trim().to_string())
}
-
- // The macro body is the most interesting part. It might end up as various
- // AST nodes, but also has special variables (e.g, `$foo`) which can't be
- // parsed as regular Rust code (and note that these can be escaped using
- // `$$`). We'll try and format like an AST node, but we'll substitute
- // variables for new names with the same length first.
-
- let old_body = context.snippet(branch.body).trim();
- let (body_str, substs) = match replace_names(old_body) {
- Some(result) => result,
- None => return snippet,
- };
-
- let mut config = context.config.clone();
- config.set().hide_parse_errors(true);
-
- result += " {";
-
- let has_block_body = old_body.starts_with('{');
-
- let body_indent = if has_block_body {
- mac_indent
- } else {
- // We'll hack the indent below, take this into account when formatting,
- let body_indent = mac_indent.block_indent(&config);
- let new_width = config.max_width() - body_indent.width();
- config.set().max_width(new_width);
- body_indent
- };
-
- // First try to format as items, then as statements.
- let new_body = match ::format_snippet(&body_str, &config) {
- Some(new_body) => new_body,
- None => match ::format_code_block(&body_str, &config) {
- Some(new_body) => new_body,
- None => return None,
- },
- };
-
- // Indent the body since it is in a block.
- let indent_str = body_indent.to_string(&config);
- let mut new_body = new_body
- .trim_right()
- .lines()
- .fold(String::new(), |mut s, l| {
- if !l.is_empty() {
- s += &indent_str;
- }
- s + l + "\n"
- });
-
- // Undo our replacement of macro variables.
- // FIXME: this could be *much* more efficient.
- for (old, new) in &substs {
- if old_body.find(new).is_some() {
- debug!(
- "rewrite_macro_def: bailing matching variable: `{}` in `{}`",
- new, ident
- );
- return None;
- }
- new_body = new_body.replace(new, old);
- }
-
- if has_block_body {
- result += new_body.trim();
- } else if !new_body.is_empty() {
- result += "\n";
- result += &new_body;
- result += &mac_indent_str;
- }
-
- result += "}";
- if def.legacy {
- result += ";";
- }
- result += "\n";
- Some(result)
+ None => None,
},
- span.lo(),
+ context.snippet_provider.span_after(span, "{"),
span.hi(),
- false
- ).collect::<Vec<_>>();
+ false,
+ )
+ .collect::<Vec<_>>();
- let arm_shape = shape
- .block_indent(context.config.tab_spaces())
- .with_max_width(context.config);
+ let fmt = ListFormatting::new(arm_shape, context.config)
+ .separator(if def.legacy { ";" } else { "" })
+ .trailing_separator(SeparatorTactic::Always)
+ .preserve_newline(true);
- let fmt = ListFormatting {
- tactic: DefinitiveListTactic::Vertical,
- separator: "",
- trailing_separator: SeparatorTactic::Never,
- separator_place: SeparatorPlace::Back,
- shape: arm_shape,
- ends_with_newline: false,
- preserve_newline: true,
- config: context.config,
- };
+ if multi_branch_style {
+ result += " {";
+ result += &arm_shape.indent.to_string_with_newline(context.config);
+ }
- result += write_list(&branch_items, &fmt)?.as_str();
+ match write_list(&branch_items, &fmt) {
+ Some(ref s) => result += s,
+ None => return snippet,
+ }
if multi_branch_style {
- result += &indent.to_string(context.config);
+ result += &indent.to_string_with_newline(context.config);
result += "}";
}
Some(result)
}
+fn register_metavariable(
+ map: &mut HashMap<String, String>,
+ result: &mut String,
+ name: &str,
+ dollar_count: usize,
+) {
+ let mut new_name = String::new();
+ let mut old_name = String::new();
+
+ old_name.push('$');
+ for _ in 0..(dollar_count - 1) {
+ new_name.push('$');
+ old_name.push('$');
+ }
+ new_name.push('z');
+ new_name.push_str(&name);
+ old_name.push_str(&name);
+
+ result.push_str(&new_name);
+ map.insert(old_name, new_name);
+}
+
// Replaces `$foo` with `zfoo`. We must check for name overlap to ensure we
// aren't causing problems.
// This should also work for escaped `$` variables, where we leave earlier `$`s.
let mut dollar_count = 0;
let mut cur_name = String::new();
- for c in input.chars() {
- if c == '$' {
+ for (kind, c) in CharClasses::new(input.chars()) {
+ if kind != FullCodeCharKind::Normal {
+ result.push(c);
+ } else if c == '$' {
dollar_count += 1;
} else if dollar_count == 0 {
result.push(c);
} else if !c.is_alphanumeric() && !cur_name.is_empty() {
// Terminates a name following one or more dollars.
- let mut new_name = String::new();
- let mut old_name = String::new();
- old_name.push('$');
- for _ in 0..(dollar_count - 1) {
- new_name.push('$');
- old_name.push('$');
- }
- new_name.push('z');
- new_name.push_str(&cur_name);
- old_name.push_str(&cur_name);
-
- result.push_str(&new_name);
- substs.insert(old_name, new_name);
+ register_metavariable(&mut substs, &mut result, &cur_name, dollar_count);
result.push(c);
-
dollar_count = 0;
- cur_name = String::new();
+ cur_name.clear();
} else if c == '(' && cur_name.is_empty() {
// FIXME: Support macro def with repeat.
return None;
- } else if c.is_alphanumeric() {
+ } else if c.is_alphanumeric() || c == '_' {
cur_name.push(c);
}
}
- // FIXME: duplicate code
if !cur_name.is_empty() {
- let mut new_name = String::new();
- let mut old_name = String::new();
- old_name.push('$');
- for _ in 0..(dollar_count - 1) {
- new_name.push('$');
- old_name.push('$');
- }
- new_name.push('z');
- new_name.push_str(&cur_name);
- old_name.push_str(&cur_name);
-
- result.push_str(&new_name);
- substs.insert(old_name, new_name);
+ register_metavariable(&mut substs, &mut result, &cur_name, dollar_count);
}
debug!("replace_names `{}` {:?}", result, substs);
Some((result, substs))
}
-// This is a bit sketchy. The token rules probably need tweaking, but it works
-// for some common cases. I hope the basic logic is sufficient. Note that the
-// meaning of some tokens is a bit different here from usual Rust, e.g., `*`
-// and `(`/`)` have special meaning.
-//
-// We always try and format on one line.
-fn format_macro_args(toks: ThinTokenStream) -> Option<String> {
- let mut result = String::with_capacity(128);
- let mut insert_space = SpaceState::Never;
+#[derive(Debug, Clone)]
+enum MacroArgKind {
+ /// e.g. `$x: expr`.
+ MetaVariable(ast::Ident, String),
+ /// e.g. `$($foo: expr),*`
+ Repeat(
+ /// `()`, `[]` or `{}`.
+ DelimToken,
+ /// Inner arguments inside delimiters.
+ Vec<ParsedMacroArg>,
+ /// Something after the closing delimiter and the repeat token, if available.
+ Option<Box<ParsedMacroArg>>,
+ /// The repeat token. This could be one of `*`, `+` or `?`.
+ Token,
+ ),
+ /// e.g. `[derive(Debug)]`
+ Delimited(DelimToken, Vec<ParsedMacroArg>),
+ /// A possible separator. e.g. `,` or `;`.
+ Separator(String, String),
+ /// Other random stuff that does not fit to other kinds.
+ /// e.g. `== foo` in `($x: expr == foo)`.
+ Other(String, String),
+}
+
+fn delim_token_to_str(
+ context: &RewriteContext,
+ delim_token: DelimToken,
+ shape: Shape,
+ use_multiple_lines: bool,
+ inner_is_empty: bool,
+) -> (String, String) {
+ let (lhs, rhs) = match delim_token {
+ DelimToken::Paren => ("(", ")"),
+ DelimToken::Bracket => ("[", "]"),
+ DelimToken::Brace => {
+ if inner_is_empty || use_multiple_lines {
+ ("{", "}")
+ } else {
+ ("{ ", " }")
+ }
+ }
+ DelimToken::NoDelim => ("", ""),
+ };
+ if use_multiple_lines {
+ let indent_str = shape.indent.to_string_with_newline(context.config);
+ let nested_indent_str = shape
+ .indent
+ .block_indent(context.config)
+ .to_string_with_newline(context.config);
+ (
+ format!("{}{}", lhs, nested_indent_str),
+ format!("{}{}", indent_str, rhs),
+ )
+ } else {
+ (lhs.to_owned(), rhs.to_owned())
+ }
+}
+
+impl MacroArgKind {
+ fn starts_with_brace(&self) -> bool {
+ match *self {
+ MacroArgKind::Repeat(DelimToken::Brace, _, _, _)
+ | MacroArgKind::Delimited(DelimToken::Brace, _) => true,
+ _ => false,
+ }
+ }
+
+ fn starts_with_dollar(&self) -> bool {
+ match *self {
+ MacroArgKind::Repeat(..) | MacroArgKind::MetaVariable(..) => true,
+ _ => false,
+ }
+ }
+
+ fn ends_with_space(&self) -> bool {
+ match *self {
+ MacroArgKind::Separator(..) => true,
+ _ => false,
+ }
+ }
+
+ fn has_meta_var(&self) -> bool {
+ match *self {
+ MacroArgKind::MetaVariable(..) => true,
+ MacroArgKind::Repeat(_, ref args, _, _) => args.iter().any(|a| a.kind.has_meta_var()),
+ _ => false,
+ }
+ }
+
+ fn rewrite(
+ &self,
+ context: &RewriteContext,
+ shape: Shape,
+ use_multiple_lines: bool,
+ ) -> Option<String> {
+ let rewrite_delimited_inner = |delim_tok, args| -> Option<(String, String, String)> {
+ let inner = wrap_macro_args(context, args, shape)?;
+ let (lhs, rhs) = delim_token_to_str(context, delim_tok, shape, false, inner.is_empty());
+ if lhs.len() + inner.len() + rhs.len() <= shape.width {
+ return Some((lhs, inner, rhs));
+ }
+
+ let (lhs, rhs) = delim_token_to_str(context, delim_tok, shape, true, false);
+ let nested_shape = shape
+ .block_indent(context.config.tab_spaces())
+ .with_max_width(context.config);
+ let inner = wrap_macro_args(context, args, nested_shape)?;
+ Some((lhs, inner, rhs))
+ };
- for tok in (toks.into(): TokenStream).trees() {
- match tok {
- TokenTree::Token(_, t) => {
- if !result.is_empty() && force_space_before(&t) {
- insert_space = SpaceState::Always;
+ match *self {
+ MacroArgKind::MetaVariable(ty, ref name) => {
+ Some(format!("${}:{}", name, ty.name.as_str()))
+ }
+ MacroArgKind::Repeat(delim_tok, ref args, ref another, ref tok) => {
+ let (lhs, inner, rhs) = rewrite_delimited_inner(delim_tok, args)?;
+ let another = another
+ .as_ref()
+ .and_then(|a| a.rewrite(context, shape, use_multiple_lines))
+ .unwrap_or_else(|| "".to_owned());
+ let repeat_tok = pprust::token_to_string(tok);
+
+ Some(format!("${}{}{}{}{}", lhs, inner, rhs, another, repeat_tok))
+ }
+ MacroArgKind::Delimited(delim_tok, ref args) => {
+ rewrite_delimited_inner(delim_tok, args)
+ .map(|(lhs, inner, rhs)| format!("{}{}{}", lhs, inner, rhs))
+ }
+ MacroArgKind::Separator(ref sep, ref prefix) => Some(format!("{}{} ", prefix, sep)),
+ MacroArgKind::Other(ref inner, ref prefix) => Some(format!("{}{}", prefix, inner)),
+ }
+ }
+}
+
+#[derive(Debug, Clone)]
+struct ParsedMacroArg {
+ kind: MacroArgKind,
+ span: Span,
+}
+
+impl ParsedMacroArg {
+ pub fn rewrite(
+ &self,
+ context: &RewriteContext,
+ shape: Shape,
+ use_multiple_lines: bool,
+ ) -> Option<String> {
+ self.kind.rewrite(context, shape, use_multiple_lines)
+ }
+}
+
+/// Parses macro arguments on macro def.
+struct MacroArgParser {
+ /// Holds either a name of the next metavariable, a separator or a junk.
+ buf: String,
+ /// The start position on the current buffer.
+ lo: BytePos,
+ /// The first token of the current buffer.
+ start_tok: Token,
+ /// Set to true if we are parsing a metavariable or a repeat.
+ is_meta_var: bool,
+ /// The position of the last token.
+ hi: BytePos,
+ /// The last token parsed.
+ last_tok: Token,
+ /// Holds the parsed arguments.
+ result: Vec<ParsedMacroArg>,
+}
+
+fn last_tok(tt: &TokenTree) -> Token {
+ match *tt {
+ TokenTree::Token(_, ref t) => t.clone(),
+ TokenTree::Delimited(_, ref d) => d.close_token(),
+ }
+}
+
+impl MacroArgParser {
+ pub fn new() -> MacroArgParser {
+ MacroArgParser {
+ lo: BytePos(0),
+ hi: BytePos(0),
+ buf: String::new(),
+ is_meta_var: false,
+ last_tok: Token::Eof,
+ start_tok: Token::Eof,
+ result: vec![],
+ }
+ }
+
+ fn set_last_tok(&mut self, tok: &TokenTree) {
+ self.hi = tok.span().hi();
+ self.last_tok = last_tok(tok);
+ }
+
+ fn add_separator(&mut self) {
+ let prefix = if self.need_space_prefix() {
+ " ".to_owned()
+ } else {
+ "".to_owned()
+ };
+ self.result.push(ParsedMacroArg {
+ kind: MacroArgKind::Separator(self.buf.clone(), prefix),
+ span: mk_sp(self.lo, self.hi),
+ });
+ self.buf.clear();
+ }
+
+ fn add_other(&mut self) {
+ let prefix = if self.need_space_prefix() {
+ " ".to_owned()
+ } else {
+ "".to_owned()
+ };
+ self.result.push(ParsedMacroArg {
+ kind: MacroArgKind::Other(self.buf.clone(), prefix),
+ span: mk_sp(self.lo, self.hi),
+ });
+ self.buf.clear();
+ }
+
+ fn add_meta_variable(&mut self, iter: &mut Cursor) -> Option<()> {
+ match iter.next() {
+ Some(TokenTree::Token(sp, Token::Ident(ref ident, _))) => {
+ self.result.push(ParsedMacroArg {
+ kind: MacroArgKind::MetaVariable(*ident, self.buf.clone()),
+ span: mk_sp(self.lo, sp.hi()),
+ });
+
+ self.buf.clear();
+ self.is_meta_var = false;
+ Some(())
+ }
+ _ => None,
+ }
+ }
+
+ fn add_delimited(&mut self, inner: Vec<ParsedMacroArg>, delim: DelimToken, span: Span) {
+ self.result.push(ParsedMacroArg {
+ kind: MacroArgKind::Delimited(delim, inner),
+ span,
+ });
+ }
+
+ // $($foo: expr),?
+ fn add_repeat(
+ &mut self,
+ inner: Vec<ParsedMacroArg>,
+ delim: DelimToken,
+ iter: &mut Cursor,
+ span: Span,
+ ) -> Option<()> {
+ let mut buffer = String::new();
+ let mut first = false;
+ let mut lo = span.lo();
+ let mut hi = span.hi();
+
+ // Parse '*', '+' or '?.
+ for tok in iter {
+ self.set_last_tok(&tok);
+ if first {
+ first = false;
+ lo = tok.span().lo();
+ }
+
+ match tok {
+ TokenTree::Token(_, Token::BinOp(BinOpToken::Plus))
+ | TokenTree::Token(_, Token::Question)
+ | TokenTree::Token(_, Token::BinOp(BinOpToken::Star)) => {
+ break;
}
- if force_no_space_before(&t) {
- insert_space = SpaceState::Never;
+ TokenTree::Token(sp, ref t) => {
+ buffer.push_str(&pprust::token_to_string(t));
+ hi = sp.hi();
}
- match (insert_space, ident_like(&t)) {
- (SpaceState::Always, _)
- | (SpaceState::Punctuation, false)
- | (SpaceState::Ident, true) => {
- result.push(' ');
+ _ => return None,
+ }
+ }
+
+ // There could be some random stuff between ')' and '*', '+' or '?'.
+ let another = if buffer.trim().is_empty() {
+ None
+ } else {
+ Some(Box::new(ParsedMacroArg {
+ kind: MacroArgKind::Other(buffer, "".to_owned()),
+ span: mk_sp(lo, hi),
+ }))
+ };
+
+ self.result.push(ParsedMacroArg {
+ kind: MacroArgKind::Repeat(delim, inner, another, self.last_tok.clone()),
+ span: mk_sp(self.lo, self.hi),
+ });
+ Some(())
+ }
+
+ fn update_buffer(&mut self, lo: BytePos, t: &Token) {
+ if self.buf.is_empty() {
+ self.lo = lo;
+ self.start_tok = t.clone();
+ } else {
+ let needs_space = match next_space(&self.last_tok) {
+ SpaceState::Ident => ident_like(t),
+ SpaceState::Punctuation => !ident_like(t),
+ SpaceState::Always => true,
+ SpaceState::Never => false,
+ };
+ if force_space_before(t) || needs_space {
+ self.buf.push(' ');
+ }
+ }
+
+ self.buf.push_str(&pprust::token_to_string(t));
+ }
+
+ fn need_space_prefix(&self) -> bool {
+ if self.result.is_empty() {
+ return false;
+ }
+
+ let last_arg = self.result.last().unwrap();
+ if let MacroArgKind::MetaVariable(..) = last_arg.kind {
+ if ident_like(&self.start_tok) {
+ return true;
+ }
+ if self.start_tok == Token::Colon {
+ return true;
+ }
+ }
+
+ if force_space_before(&self.start_tok) {
+ return true;
+ }
+
+ false
+ }
+
+ /// Returns a collection of parsed macro def's arguments.
+ pub fn parse(mut self, tokens: ThinTokenStream) -> Option<Vec<ParsedMacroArg>> {
+ let stream: TokenStream = tokens.into();
+ let mut iter = stream.trees();
+
+ while let Some(ref tok) = iter.next() {
+ match tok {
+ TokenTree::Token(sp, Token::Dollar) => {
+ // We always want to add a separator before meta variables.
+ if !self.buf.is_empty() {
+ self.add_separator();
}
- _ => {}
+
+ // Start keeping the name of this metavariable in the buffer.
+ self.is_meta_var = true;
+ self.lo = sp.lo();
+ self.start_tok = Token::Dollar;
}
- result.push_str(&pprust::token_to_string(&t));
- insert_space = next_space(&t);
- }
- TokenTree::Delimited(_, d) => {
- if let SpaceState::Always = insert_space {
- result.push(' ');
+ TokenTree::Token(_, Token::Colon) if self.is_meta_var => {
+ self.add_meta_variable(&mut iter)?;
}
- let formatted = format_macro_args(d.tts)?;
- match d.delim {
- DelimToken::Paren => {
- result.push_str(&format!("({})", formatted));
- insert_space = SpaceState::Always;
- }
- DelimToken::Bracket => {
- result.push_str(&format!("[{}]", formatted));
- insert_space = SpaceState::Always;
- }
- DelimToken::Brace => {
- result.push_str(&format!(" {{ {} }}", formatted));
- insert_space = SpaceState::Always;
+ TokenTree::Token(sp, ref t) => self.update_buffer(sp.lo(), t),
+ TokenTree::Delimited(delimited_span, delimited) => {
+ if !self.buf.is_empty() {
+ if next_space(&self.last_tok) == SpaceState::Always {
+ self.add_separator();
+ } else {
+ self.add_other();
+ }
}
- DelimToken::NoDelim => {
- result.push_str(&format!("{}", formatted));
- insert_space = SpaceState::Always;
+
+ // Parse the stuff inside delimiters.
+ let mut parser = MacroArgParser::new();
+ parser.lo = delimited_span.open.lo();
+ let delimited_arg = parser.parse(delimited.tts.clone())?;
+
+ let span = delimited_span.entire();
+ if self.is_meta_var {
+ self.add_repeat(delimited_arg, delimited.delim, &mut iter, span)?;
+ self.is_meta_var = false;
+ } else {
+ self.add_delimited(delimited_arg, delimited.delim, span);
}
}
}
+
+ self.set_last_tok(tok);
}
+
+ // We are left with some stuff in the buffer. Since there is nothing
+ // left to separate, add this as `Other`.
+ if !self.buf.is_empty() {
+ self.add_other();
+ }
+
+ Some(self.result)
}
+}
- Some(result)
+fn wrap_macro_args(
+ context: &RewriteContext,
+ args: &[ParsedMacroArg],
+ shape: Shape,
+) -> Option<String> {
+ wrap_macro_args_inner(context, args, shape, false)
+ .or_else(|| wrap_macro_args_inner(context, args, shape, true))
+}
+
+fn wrap_macro_args_inner(
+ context: &RewriteContext,
+ args: &[ParsedMacroArg],
+ shape: Shape,
+ use_multiple_lines: bool,
+) -> Option<String> {
+ let mut result = String::with_capacity(128);
+ let mut iter = args.iter().peekable();
+ let indent_str = shape.indent.to_string_with_newline(context.config);
+
+ while let Some(ref arg) = iter.next() {
+ result.push_str(&arg.rewrite(context, shape, use_multiple_lines)?);
+
+ if use_multiple_lines
+ && (arg.kind.ends_with_space() || iter.peek().map_or(false, |a| a.kind.has_meta_var()))
+ {
+ if arg.kind.ends_with_space() {
+ result.pop();
+ }
+ result.push_str(&indent_str);
+ } else if let Some(ref next_arg) = iter.peek() {
+ let space_before_dollar =
+ !arg.kind.ends_with_space() && next_arg.kind.starts_with_dollar();
+ let space_before_brace = next_arg.kind.starts_with_brace();
+ if space_before_dollar || space_before_brace {
+ result.push(' ');
+ }
+ }
+ }
+
+ if !use_multiple_lines && result.len() >= shape.width {
+ None
+ } else {
+ Some(result)
+ }
+}
+
+// This is a bit sketchy. The token rules probably need tweaking, but it works
+// for some common cases. I hope the basic logic is sufficient. Note that the
+// meaning of some tokens is a bit different here from usual Rust, e.g., `*`
+// and `(`/`)` have special meaning.
+//
+// We always try and format on one line.
+// FIXME: Use multi-line when every thing does not fit on one line.
+fn format_macro_args(
+ context: &RewriteContext,
+ toks: ThinTokenStream,
+ shape: Shape,
+) -> Option<String> {
+ if !context.config.format_macro_matchers() {
+ let token_stream: TokenStream = toks.into();
+ let span = span_for_token_stream(&token_stream);
+ return Some(match span {
+ Some(span) => context.snippet(span).to_owned(),
+ None => String::new(),
+ });
+ }
+ let parsed_args = MacroArgParser::new().parse(toks)?;
+ wrap_macro_args(context, &parsed_args, shape)
+}
+
+fn span_for_token_stream(token_stream: &TokenStream) -> Option<Span> {
+ token_stream.trees().next().map(|tt| tt.span())
}
// We should insert a space if the next token is a:
-#[derive(Copy, Clone)]
+#[derive(Copy, Clone, PartialEq)]
enum SpaceState {
Never,
Punctuation,
}
fn force_space_before(tok: &Token) -> bool {
- match *tok {
+ debug!("tok: force_space_before {:?}", tok);
+
+ match tok {
Token::Eq
| Token::Lt
| Token::Le
| Token::RArrow
| Token::LArrow
| Token::FatArrow
+ | Token::BinOp(_)
| Token::Pound
| Token::Dollar => true,
- Token::BinOp(bot) => bot != BinOpToken::Star,
_ => false,
}
}
-fn force_no_space_before(tok: &Token) -> bool {
- match *tok {
- Token::Semi | Token::Comma | Token::Dot => true,
- Token::BinOp(bot) => bot == BinOpToken::Star,
- _ => false,
- }
-}
fn ident_like(tok: &Token) -> bool {
- match *tok {
- Token::Ident(_) | Token::Literal(..) | Token::Lifetime(_) => true,
+ match tok {
+ Token::Ident(..) | Token::Literal(..) | Token::Lifetime(_) => true,
_ => false,
}
}
fn next_space(tok: &Token) -> SpaceState {
- match *tok {
+ debug!("next_space: {:?}", tok);
+
+ match tok {
Token::Not
+ | Token::BinOp(BinOpToken::And)
| Token::Tilde
| Token::At
| Token::Comma
| Token::DotDot
| Token::DotDotDot
| Token::DotDotEq
- | Token::DotEq
- | Token::Question
- | Token::Underscore
- | Token::BinOp(_) => SpaceState::Punctuation,
+ | Token::Question => SpaceState::Punctuation,
Token::ModSep
| Token::Pound
| Token::CloseDelim(_)
| Token::Whitespace => SpaceState::Never,
- Token::Literal(..) | Token::Ident(_) | Token::Lifetime(_) => SpaceState::Ident,
+ Token::Literal(..) | Token::Ident(..) | Token::Lifetime(_) => SpaceState::Ident,
_ => SpaceState::Always,
}
/// when the macro is not an instance of try! (or parsing the inner expression
/// failed).
pub fn convert_try_mac(mac: &ast::Mac, context: &RewriteContext) -> Option<ast::Expr> {
- if &format!("{}", mac.node.path)[..] == "try" {
+ if &mac.node.path.to_string() == "try" {
let ts: TokenStream = mac.node.tts.clone().into();
let mut parser = new_parser_from_tts(context.parse_session, ts.trees().collect());
Some(ast::Expr {
- id: ast::NodeId::new(0), // dummy value
+ id: ast::NodeId::root(), // dummy value
node: ast::ExprKind::Try(parser.parse_expr().ok()?),
span: mac.span, // incorrect span, but shouldn't matter too much
attrs: ThinVec::new(),
}
}
-fn macro_style(mac: &ast::Mac, context: &RewriteContext) -> MacroStyle {
+fn macro_style(mac: &ast::Mac, context: &RewriteContext) -> DelimToken {
let snippet = context.snippet(mac.span);
let paren_pos = snippet.find_uncommented("(").unwrap_or(usize::max_value());
let bracket_pos = snippet.find_uncommented("[").unwrap_or(usize::max_value());
let brace_pos = snippet.find_uncommented("{").unwrap_or(usize::max_value());
if paren_pos < bracket_pos && paren_pos < brace_pos {
- MacroStyle::Parens
+ DelimToken::Paren
} else if bracket_pos < brace_pos {
- MacroStyle::Brackets
+ DelimToken::Bracket
} else {
- MacroStyle::Braces
- }
-}
-
-/// Indent each line according to the specified `indent`.
-/// e.g.
-/// ```rust
-/// foo!{
-/// x,
-/// y,
-/// foo(
-/// a,
-/// b,
-/// c,
-/// ),
-/// }
-/// ```
-/// will become
-/// ```rust
-/// foo!{
-/// x,
-/// y,
-/// foo(
-/// a,
-/// b,
-/// c,
-// ),
-/// }
-/// ```
-fn indent_macro_snippet(
- context: &RewriteContext,
- macro_str: &str,
- indent: Indent,
-) -> Option<String> {
- let mut lines = macro_str.lines();
- let first_line = lines.next().map(|s| s.trim_right())?;
- let mut trimmed_lines = Vec::with_capacity(16);
-
- let min_prefix_space_width = lines
- .filter_map(|line| {
- let prefix_space_width = if is_empty_line(line) {
- None
- } else {
- Some(get_prefix_space_width(context, line))
- };
- trimmed_lines.push((line.trim(), prefix_space_width));
- prefix_space_width
- })
- .min()?;
-
- Some(
- String::from(first_line) + "\n"
- + &trimmed_lines
- .iter()
- .map(|&(line, prefix_space_width)| match prefix_space_width {
- Some(original_indent_width) => {
- let new_indent_width = indent.width()
- + original_indent_width
- .checked_sub(min_prefix_space_width)
- .unwrap_or(0);
- let new_indent = Indent::from_width(context.config, new_indent_width);
- format!("{}{}", new_indent.to_string(context.config), line.trim())
- }
- None => String::new(),
- })
- .collect::<Vec<_>>()
- .join("\n"),
- )
-}
-
-fn get_prefix_space_width(context: &RewriteContext, s: &str) -> usize {
- let mut width = 0;
- for c in s.chars() {
- match c {
- ' ' => width += 1,
- '\t' => width += context.config.tab_spaces(),
- _ => return width,
- }
+ DelimToken::Brace
}
- width
-}
-
-fn is_empty_line(s: &str) -> bool {
- s.is_empty() || s.chars().all(char::is_whitespace)
}
// A very simple parser that just parses a macros 2.0 definition into its branches.
// `(` ... `)` `=>` `{` ... `}`
fn parse_branch(&mut self) -> Option<MacroBranch> {
let tok = self.toks.next()?;
- let (args_span, args_paren_kind) = match tok {
+ let (lo, args_paren_kind) = match tok {
TokenTree::Token(..) => return None,
- TokenTree::Delimited(sp, ref d) => (sp, d.delim),
+ TokenTree::Delimited(delimited_span, ref d) => (delimited_span.open.lo(), d.delim),
};
let args = tok.joint().into();
match self.toks.next()? {
TokenTree::Token(_, Token::FatArrow) => {}
_ => return None,
}
- let body = match self.toks.next()? {
+ let (mut hi, body, whole_body) = match self.toks.next()? {
TokenTree::Token(..) => return None,
- TokenTree::Delimited(sp, _) => {
- let data = sp.data();
- Span::new(data.lo + BytePos(1), data.hi - BytePos(1), data.ctxt)
+ TokenTree::Delimited(delimited_span, _) => {
+ let data = delimited_span.entire().data();
+ (
+ data.hi,
+ Span::new(data.lo + BytePos(1), data.hi - BytePos(1), data.ctxt),
+ delimited_span.entire(),
+ )
}
};
- if let Some(TokenTree::Token(_, Token::Semi)) = self.toks.look_ahead(0) {
+ if let Some(TokenTree::Token(sp, Token::Semi)) = self.toks.look_ahead(0) {
self.toks.next();
+ hi = sp.hi();
}
Some(MacroBranch {
+ span: mk_sp(lo, hi),
args_paren_kind,
- args_span,
args,
body,
+ whole_body,
})
}
}
// FIXME: it would be more efficient to use references to the token streams
// rather than clone them, if we can make the borrowing work out.
struct MacroBranch {
+ span: Span,
args_paren_kind: DelimToken,
- args_span: Span,
args: ThinTokenStream,
body: Span,
+ whole_body: Span,
}
-#[cfg(test)]
-mod test {
- use super::*;
- use syntax::parse::{parse_stream_from_source_str, ParseSess};
- use syntax::codemap::{FileName, FilePathMapping};
+impl MacroBranch {
+ fn rewrite(
+ &self,
+ context: &RewriteContext,
+ shape: Shape,
+ multi_branch_style: bool,
+ ) -> Option<String> {
+ // Only attempt to format function-like macros.
+ if self.args_paren_kind != DelimToken::Paren {
+ // FIXME(#1539): implement for non-sugared macros.
+ return None;
+ }
+
+ // 5 = " => {"
+ let mut result = format_macro_args(context, self.args.clone(), shape.sub_width(5)?)?;
- fn format_macro_args_str(s: &str) -> String {
- let input = parse_stream_from_source_str(
- FileName::Custom("stdin".to_owned()),
- s.to_owned(),
- &ParseSess::new(FilePathMapping::empty()),
- None,
- );
- format_macro_args(input.into()).unwrap()
+ if multi_branch_style {
+ result += " =>";
+ }
+
+ if !context.config.format_macro_bodies() {
+ result += " ";
+ result += context.snippet(self.whole_body);
+ return Some(result);
+ }
+
+ // The macro body is the most interesting part. It might end up as various
+ // AST nodes, but also has special variables (e.g, `$foo`) which can't be
+ // parsed as regular Rust code (and note that these can be escaped using
+ // `$$`). We'll try and format like an AST node, but we'll substitute
+ // variables for new names with the same length first.
+
+ let old_body = context.snippet(self.body).trim();
+ let (body_str, substs) = replace_names(old_body)?;
+ let has_block_body = old_body.starts_with('{');
+
+ let mut config = context.config.clone();
+ config.set().hide_parse_errors(true);
+
+ result += " {";
+
+ let body_indent = if has_block_body {
+ shape.indent
+ } else {
+ shape.indent.block_indent(&config)
+ };
+ let new_width = config.max_width() - body_indent.width();
+ config.set().max_width(new_width);
+
+ // First try to format as items, then as statements.
+ let new_body_snippet = match ::format_snippet(&body_str, &config) {
+ Some(new_body) => new_body,
+ None => {
+ let new_width = new_width + config.tab_spaces();
+ config.set().max_width(new_width);
+ match ::format_code_block(&body_str, &config) {
+ Some(new_body) => new_body,
+ None => return None,
+ }
+ }
+ };
+ let new_body = wrap_str(
+ new_body_snippet.snippet.to_string(),
+ config.max_width(),
+ shape,
+ )?;
+
+ // Indent the body since it is in a block.
+ let indent_str = body_indent.to_string(&config);
+ let mut new_body = LineClasses::new(new_body.trim_end())
+ .enumerate()
+ .fold(
+ (String::new(), true),
+ |(mut s, need_indent), (i, (kind, ref l))| {
+ if !is_empty_line(l)
+ && need_indent
+ && !new_body_snippet.is_line_non_formatted(i + 1)
+ {
+ s += &indent_str;
+ }
+ (s + l + "\n", !kind.is_string() || l.ends_with('\\'))
+ },
+ )
+ .0;
+
+ // Undo our replacement of macro variables.
+ // FIXME: this could be *much* more efficient.
+ for (old, new) in &substs {
+ if old_body.find(new).is_some() {
+ debug!("rewrite_macro_def: bailing matching variable: `{}`", new);
+ return None;
+ }
+ new_body = new_body.replace(new, old);
+ }
+
+ if has_block_body {
+ result += new_body.trim();
+ } else if !new_body.is_empty() {
+ result += "\n";
+ result += &new_body;
+ result += &shape.indent.to_string(&config);
+ }
+
+ result += "}";
+
+ Some(result)
}
+}
- #[test]
- fn test_format_macro_args() {
- assert_eq!(format_macro_args_str(""), "".to_owned());
- assert_eq!(format_macro_args_str("$ x : ident"), "$x: ident".to_owned());
- assert_eq!(
- format_macro_args_str("$ m1 : ident , $ m2 : ident , $ x : ident"),
- "$m1: ident, $m2: ident, $x: ident".to_owned()
- );
- assert_eq!(
- format_macro_args_str("$($beginning:ident),*;$middle:ident;$($end:ident),*"),
- "$($beginning: ident),*; $middle: ident; $($end: ident),*".to_owned()
- );
- assert_eq!(
- format_macro_args_str(
- "$ name : ident ( $ ( $ dol : tt $ var : ident ) * ) $ ( $ body : tt ) *"
- ),
- "$name: ident($($dol: tt $var: ident)*) $($body: tt)*".to_owned()
- );
+/// Format `lazy_static!` from https://crates.io/crates/lazy_static.
+///
+/// # Expected syntax
+///
+/// ```ignore
+/// lazy_static! {
+/// [pub] static ref NAME_1: TYPE_1 = EXPR_1;
+/// [pub] static ref NAME_2: TYPE_2 = EXPR_2;
+/// ...
+/// [pub] static ref NAME_N: TYPE_N = EXPR_N;
+/// }
+/// ```
+fn format_lazy_static(context: &RewriteContext, shape: Shape, ts: &TokenStream) -> Option<String> {
+ let mut result = String::with_capacity(1024);
+ let mut parser = new_parser_from_tts(context.parse_session, ts.trees().collect());
+ let nested_shape = shape
+ .block_indent(context.config.tab_spaces())
+ .with_max_width(context.config);
+
+ result.push_str("lazy_static! {");
+ result.push_str(&nested_shape.indent.to_string_with_newline(context.config));
+
+ macro_rules! parse_or {
+ ($method:ident $(,)* $($arg:expr),* $(,)*) => {
+ match parser.$method($($arg,)*) {
+ Ok(val) => {
+ if parser.sess.span_diagnostic.has_errors() {
+ parser.sess.span_diagnostic.reset_err_count();
+ return None;
+ } else {
+ val
+ }
+ }
+ Err(mut err) => {
+ err.cancel();
+ parser.sess.span_diagnostic.reset_err_count();
+ return None;
+ }
+ }
+ }
+ }
+
+ while parser.token != Token::Eof {
+ // Parse a `lazy_static!` item.
+ let vis = ::utils::format_visibility(context, &parse_or!(parse_visibility, false));
+ parser.eat_keyword(symbol::keywords::Static);
+ parser.eat_keyword(symbol::keywords::Ref);
+ let id = parse_or!(parse_ident);
+ parser.eat(&Token::Colon);
+ let ty = parse_or!(parse_ty);
+ parser.eat(&Token::Eq);
+ let expr = parse_or!(parse_expr);
+ parser.eat(&Token::Semi);
+
+ // Rewrite as a static item.
+ let mut stmt = String::with_capacity(128);
+ stmt.push_str(&format!(
+ "{}static ref {}: {} =",
+ vis,
+ id,
+ ty.rewrite(context, nested_shape)?
+ ));
+ result.push_str(&::expr::rewrite_assign_rhs(
+ context,
+ stmt,
+ &*expr,
+ nested_shape.sub_width(1)?,
+ )?);
+ result.push(';');
+ if parser.token != Token::Eof {
+ result.push_str(&nested_shape.indent.to_string_with_newline(context.config));
+ }
}
+
+ result.push_str(&shape.indent.to_string_with_newline(context.config));
+ result.push('}');
+
+ Some(result)
+}
+
+fn rewrite_macro_with_items(
+ context: &RewriteContext,
+ items: &[MacroArg],
+ macro_name: &str,
+ shape: Shape,
+ style: DelimToken,
+ position: MacroPosition,
+ span: Span,
+) -> Option<String> {
+ let (opener, closer) = match style {
+ DelimToken::Paren => ("(", ")"),
+ DelimToken::Bracket => ("[", "]"),
+ DelimToken::Brace => (" {", "}"),
+ _ => return None,
+ };
+ let trailing_semicolon = match style {
+ DelimToken::Paren | DelimToken::Bracket if position == MacroPosition::Item => ";",
+ _ => "",
+ };
+
+ let mut visitor = FmtVisitor::from_context(context);
+ visitor.block_indent = shape.indent.block_indent(context.config);
+ visitor.last_pos = context.snippet_provider.span_after(span, opener.trim());
+ for item in items {
+ let item = match item {
+ MacroArg::Item(item) => item,
+ _ => return None,
+ };
+ visitor.visit_item(&item);
+ }
+
+ let mut result = String::with_capacity(256);
+ result.push_str(¯o_name);
+ result.push_str(opener);
+ result.push_str(&visitor.block_indent.to_string_with_newline(context.config));
+ result.push_str(visitor.buffer.trim());
+ result.push_str(&shape.indent.to_string_with_newline(context.config));
+ result.push_str(closer);
+ result.push_str(trailing_semicolon);
+ Some(result)
}