]> git.lizzy.rs Git - rust.git/blobdiff - src/macros.rs
Fix treating the delimiter right after repeat as repeat as well
[rust.git] / src / macros.rs
index e600b1196784d95aba04e35059df5d7c83d5fcae..300f95c301d0a626b8e16b34904088e4aa28e405 100644 (file)
@@ -22,7 +22,6 @@
 use std::collections::HashMap;
 
 use config::lists::*;
-use syntax::{ast, ptr};
 use syntax::codemap::{BytePos, Span};
 use syntax::parse::new_parser_from_tts;
 use syntax::parse::parser::Parser;
 use syntax::symbol;
 use syntax::tokenstream::{Cursor, ThinTokenStream, TokenStream, TokenTree};
 use syntax::util::ThinVec;
+use syntax::{ast, ptr};
 
 use codemap::SpanUtils;
-use comment::{contains_comment, remove_trailing_white_spaces, CharClasses, FindUncommented,
-              FullCodeCharKind};
+use comment::{
+    contains_comment, remove_trailing_white_spaces, CharClasses, FindUncommented, FullCodeCharKind,
+    LineClasses,
+};
 use expr::rewrite_array;
 use lists::{itemize_list, write_list, ListFormatting};
 use overflow;
 
 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,
@@ -61,23 +55,12 @@ pub enum MacroPosition {
     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>),
-    // `parse_item` returns `Option<ptr::P<ast::Item>>`.
-    Item(Option<ptr::P<ast::Item>>),
+    Item(ptr::P<ast::Item>),
 }
 
 impl Rewrite for ast::Item {
@@ -96,14 +79,14 @@ fn rewrite(&self, context: &RewriteContext, shape: Shape) -> Option<String> {
             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.as_ref().and_then(|item| item.rewrite(context, shape)),
+            MacroArg::Item(ref item) => item.rewrite(context, shape),
         }
     }
 }
 
 fn parse_macro_arg(parser: &mut Parser) -> Option<MacroArg> {
     macro_rules! parse_macro_arg {
-        ($macro_arg: ident, $parser: ident) => {
+        ($macro_arg:ident, $parser:ident, $f:expr) => {
             let mut cloned_parser = (*parser).clone();
             match cloned_parser.$parser() {
                 Ok(x) => {
@@ -112,7 +95,7 @@ macro_rules! parse_macro_arg {
                     } else {
                         // Parsing succeeded.
                         *parser = cloned_parser;
-                        return Some(MacroArg::$macro_arg(x.clone()));
+                        return Some(MacroArg::$macro_arg($f(x)?));
                     }
                 }
                 Err(mut e) => {
@@ -123,10 +106,11 @@ macro_rules! parse_macro_arg {
         };
     }
 
-    parse_macro_arg!(Expr, parse_expr);
-    parse_macro_arg!(Ty, parse_ty);
-    parse_macro_arg!(Pat, parse_pat);
-    parse_macro_arg!(Item, parse_item);
+    parse_macro_arg!(Expr, parse_expr, |x: ptr::P<ast::Expr>| Some(x));
+    parse_macro_arg!(Ty, parse_ty, |x: ptr::P<ast::Ty>| Some(x));
+    parse_macro_arg!(Pat, parse_pat, |x: ptr::P<ast::Pat>| Some(x));
+    // `parse_item` returns `Option<ptr::P<ast::Item>>`.
+    parse_macro_arg!(Item, parse_item, |x: Option<ptr::P<ast::Item>>| x);
 
     None
 }
@@ -135,7 +119,7 @@ macro_rules! parse_macro_arg {
 fn rewrite_macro_name(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!("{}!", path.segments[0].identifier)
+        format!("{}!", path.segments[0].ident)
     } else {
         format!("{}!", path)
     };
@@ -152,11 +136,22 @@ pub fn rewrite_macro(
     shape: Shape,
     position: MacroPosition,
 ) -> Option<String> {
-    let context = &mut context.clone();
-    context.inside_macro = true;
+    context.inside_macro.replace(true);
+    let result = rewrite_macro_inner(mac, extra_ident, context, shape, position);
+    context.inside_macro.replace(false);
+    result
+}
+
+pub fn rewrite_macro_inner(
+    mac: &ast::Mac,
+    extra_ident: Option<ast::Ident>,
+    context: &RewriteContext,
+    shape: Shape,
+    position: MacroPosition,
+) -> 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);
         }
     }
@@ -166,7 +161,7 @@ pub fn rewrite_macro(
     let macro_name = rewrite_macro_name(&mac.node.path, extra_ident);
 
     let style = if FORCED_BRACKET_MACROS.contains(&&macro_name[..]) {
-        MacroStyle::Brackets
+        DelimToken::Bracket
     } else {
         original_style
     };
@@ -175,12 +170,13 @@ pub fn rewrite_macro(
     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.
@@ -196,7 +192,7 @@ pub fn rewrite_macro(
     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),
@@ -239,13 +235,13 @@ pub fn rewrite_macro(
     }
 
     match style {
-        MacroStyle::Parens => {
+        DelimToken::Paren => {
             // Format macro invocation as function call, preserve the trailing
             // comma because not all macros support them.
             overflow::rewrite_with_parens(
                 context,
                 &macro_name,
-                &arg_vec.iter().map(|e| &*e).collect::<Vec<_>>()[..],
+                &arg_vec.iter().map(|e| &*e).collect::<Vec<_>>(),
                 shape,
                 mac.span,
                 context.config.width_heuristics().fn_call_width,
@@ -259,66 +255,71 @@ pub fn rewrite_macro(
                 _ => 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!(
-                        "{}{}{}{};{}{}{}{}",
+                        "{}[{}{};{}{}{}]",
                         macro_name,
-                        lbr,
                         nested_shape.indent.to_string_with_newline(context.config),
                         lhs,
                         nested_shape.indent.to_string_with_newline(context.config),
                         rhs,
                         shape.indent.to_string_with_newline(context.config),
-                        rbr
                     ))
                 }
             } 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(&macro_name.as_str()) {
-                    context.inside_macro = false;
-                    trailing_comma = false;
+                let macro_name = &macro_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) {
+                    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
-                        .snippet_provider
-                        .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)?;
+                let arg_vec = &arg_vec.iter().map(|e| &*e).collect::<Vec<_>>();
+                let rewrite = rewrite_array(
+                    macro_name,
+                    arg_vec,
+                    mac.span,
+                    context,
+                    shape,
+                    force_trailing_comma,
+                    Some(original_style),
+                )?;
                 let comma = match position {
                     MacroPosition::Item => ";",
                     _ => "",
                 };
 
-                Some(format!("{}{}{}", macro_name, rewrite, comma))
+                Some(format!("{}{}", rewrite, comma))
             }
         }
-        MacroStyle::Braces => {
+        DelimToken::Brace => {
             // Skip macro invocations with braces, for now.
             indent_macro_snippet(context, context.snippet(mac.span), shape.indent)
         }
+        _ => unreachable!(),
     }
 }
 
@@ -449,7 +450,7 @@ fn replace_names(input: &str) -> Option<(String, HashMap<String, String>)> {
         } 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);
         }
     }
@@ -465,15 +466,25 @@ fn replace_names(input: &str) -> Option<(String, HashMap<String, String>)> {
 
 #[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),
 }
 
@@ -486,7 +497,7 @@ fn delim_token_to_str(
     let (lhs, rhs) = match *delim_token {
         DelimToken::Paren => ("(", ")"),
         DelimToken::Bracket => ("[", "]"),
-        DelimToken::Brace => ("{", "}"),
+        DelimToken::Brace => ("{ ", " }"),
         DelimToken::NoDelim => ("", ""),
     };
     if use_multiple_lines {
@@ -505,6 +516,14 @@ fn delim_token_to_str(
 }
 
 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,
@@ -519,6 +538,14 @@ fn ends_with_space(&self) -> bool {
         }
     }
 
+    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,
@@ -542,14 +569,14 @@ fn rewrite(
 
         match *self {
             MacroArgKind::MetaVariable(ty, ref name) => {
-                Some(format!("${}: {}", name, ty.name.as_str()))
+                Some(format!("${}:{}", name, ty.name.as_str()))
             }
             MacroArgKind::Repeat(ref 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("".to_owned());
+                    .unwrap_or_else(|| "".to_owned());
                 let repeat_tok = pprust::token_to_string(tok);
 
                 Some(format!("${}{}{}{}{}", lhs, inner, rhs, another, repeat_tok))
@@ -581,13 +608,21 @@ pub fn rewrite(
     }
 }
 
+/// 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,
-    buf: String,
-    is_arg: bool,
+    /// The last token parsed.
     last_tok: Token,
-    start_tok: Token,
+    /// Holds the parsed arguments.
     result: Vec<ParsedMacroArg>,
 }
 
@@ -604,7 +639,7 @@ pub fn new() -> MacroArgParser {
             lo: BytePos(0),
             hi: BytePos(0),
             buf: String::new(),
-            is_arg: false,
+            is_meta_var: false,
             last_tok: Token::Eof,
             start_tok: Token::Eof,
             result: vec![],
@@ -642,27 +677,95 @@ fn add_other(&mut self) {
         self.buf.clear();
     }
 
-    fn add_meta_variable(&mut self, iter: &mut Cursor) {
+    fn add_meta_variable(&mut self, iter: &mut Cursor) -> Option<()> {
         match iter.next() {
-            Some(TokenTree::Token(sp, Token::Ident(ref ident))) => {
+            Some(TokenTree::Token(sp, Token::Ident(ref ident, _))) => {
                 self.result.push(ParsedMacroArg {
-                    kind: MacroArgKind::MetaVariable(ident.clone(), self.buf.clone()),
+                    kind: MacroArgKind::MetaVariable(*ident, self.buf.clone()),
                     span: mk_sp(self.lo, sp.hi()),
                 });
 
                 self.buf.clear();
-                self.is_arg = false;
+                self.is_meta_var = false;
+                Some(())
             }
-            _ => unreachable!(),
+            _ => 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 ref 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;
+                }
+                TokenTree::Token(sp, ref t) => {
+                    buffer.push_str(&pprust::token_to_string(t));
+                    hi = sp.hi();
+                }
+                _ => 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 if force_space_before(t) {
-            self.buf.push(' ');
+        } 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));
@@ -678,6 +781,9 @@ fn need_space_prefix(&self) -> bool {
             if ident_like(&self.start_tok) {
                 return true;
             }
+            if self.start_tok == Token::Colon {
+                return true;
+            }
         }
 
         if force_space_before(&self.start_tok) {
@@ -688,7 +794,7 @@ fn need_space_prefix(&self) -> bool {
     }
 
     /// Returns a collection of parsed macro def's arguments.
-    pub fn parse(mut self, tokens: ThinTokenStream) -> Vec<ParsedMacroArg> {
+    pub fn parse(mut self, tokens: ThinTokenStream) -> Option<Vec<ParsedMacroArg>> {
         let mut iter = (tokens.into(): TokenStream).trees();
 
         while let Some(ref tok) = iter.next() {
@@ -700,15 +806,15 @@ pub fn parse(mut self, tokens: ThinTokenStream) -> Vec<ParsedMacroArg> {
                     }
 
                     // Start keeping the name of this metavariable in the buffer.
-                    self.is_arg = true;
+                    self.is_meta_var = true;
                     self.lo = sp.lo();
                     self.start_tok = Token::Dollar;
                 }
-                TokenTree::Token(_, Token::Colon) if self.is_arg => {
-                    self.add_meta_variable(&mut iter);
+                TokenTree::Token(_, Token::Colon) if self.is_meta_var => {
+                    self.add_meta_variable(&mut iter)?;
                 }
                 TokenTree::Token(sp, ref t) => self.update_buffer(sp.lo(), t),
-                TokenTree::Delimited(sp, ref delimited) => {
+                TokenTree::Delimited(sp, delimited) => {
                     if !self.buf.is_empty() {
                         if next_space(&self.last_tok) == SpaceState::Always {
                             self.add_separator();
@@ -717,59 +823,16 @@ pub fn parse(mut self, tokens: ThinTokenStream) -> Vec<ParsedMacroArg> {
                         }
                     }
 
+                    // Parse the stuff inside delimiters.
                     let mut parser = MacroArgParser::new();
                     parser.lo = sp.lo();
-                    let mut delimited_arg = parser.parse(delimited.tts.clone());
-
-                    if self.is_arg {
-                        // Parse '*' or '+'.
-                        let mut buffer = String::new();
-                        let mut first = false;
-                        let mut lo = sp.lo();
-
-                        while let Some(ref next_tok) = iter.next() {
-                            self.set_last_tok(next_tok);
-                            if first {
-                                first = false;
-                                lo = next_tok.span().lo();
-                            }
+                    let delimited_arg = parser.parse(delimited.tts.clone())?;
 
-                            match next_tok {
-                                TokenTree::Token(_, Token::BinOp(BinOpToken::Plus))
-                                | TokenTree::Token(_, Token::Question)
-                                | TokenTree::Token(_, Token::BinOp(BinOpToken::Star)) => {
-                                    break;
-                                }
-                                TokenTree::Token(_, ref t) => {
-                                    buffer.push_str(&pprust::token_to_string(t))
-                                }
-                                _ => unreachable!(),
-                            }
-                        }
-
-                        let another = if buffer.trim().is_empty() {
-                            None
-                        } else {
-                            Some(Box::new(ParsedMacroArg {
-                                kind: MacroArgKind::Other(buffer, "".to_owned()),
-                                span: mk_sp(lo, self.hi),
-                            }))
-                        };
-
-                        self.result.push(ParsedMacroArg {
-                            kind: MacroArgKind::Repeat(
-                                delimited.delim,
-                                delimited_arg,
-                                another,
-                                self.last_tok.clone(),
-                            ),
-                            span: mk_sp(self.lo, self.hi),
-                        });
+                    if self.is_meta_var {
+                        self.add_repeat(delimited_arg, delimited.delim, &mut iter, *sp)?;
+                        self.is_meta_var = false;
                     } else {
-                        self.result.push(ParsedMacroArg {
-                            kind: MacroArgKind::Delimited(delimited.delim, delimited_arg),
-                            span: *sp,
-                        });
+                        self.add_delimited(delimited_arg, delimited.delim, *sp);
                     }
                 }
             }
@@ -777,11 +840,13 @@ pub fn parse(mut self, tokens: ThinTokenStream) -> Vec<ParsedMacroArg> {
             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();
         }
 
-        self.result
+        Some(self.result)
     }
 }
 
@@ -805,20 +870,20 @@ fn wrap_macro_args_inner(
     let indent_str = shape.indent.to_string_with_newline(context.config);
 
     while let Some(ref arg) = iter.next() {
-        let nested_shape = if use_multiple_lines {
-            shape.with_max_width(context.config)
-        } else {
-            shape
-        };
-        result.push_str(&arg.rewrite(context, nested_shape, use_multiple_lines)?);
+        result.push_str(&arg.rewrite(context, shape, use_multiple_lines)?);
 
-        if use_multiple_lines && arg.kind.ends_with_space() {
-            result.pop();
+        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();
-            if space_before_dollar {
+            let space_before_brace = next_arg.kind.starts_with_brace();
+            if space_before_dollar || space_before_brace {
                 result.push(' ');
             }
         }
@@ -843,7 +908,7 @@ fn format_macro_args(
     toks: ThinTokenStream,
     shape: Shape,
 ) -> Option<String> {
-    let parsed_args = MacroArgParser::new().parse(toks);
+    let parsed_args = MacroArgParser::new().parse(toks)?;
     wrap_macro_args(context, &parsed_args, shape)
 }
 
@@ -876,16 +941,16 @@ fn force_space_before(tok: &Token) -> bool {
         | Token::RArrow
         | Token::LArrow
         | Token::FatArrow
+        | Token::BinOp(_)
         | Token::Pound
         | Token::Dollar => true,
-        Token::BinOp(bot) => bot != BinOpToken::Star,
         _ => false,
     }
 }
 
 fn ident_like(tok: &Token) -> bool {
     match *tok {
-        Token::Ident(_) | Token::Literal(..) | Token::Lifetime(_) => true,
+        Token::Ident(..) | Token::Literal(..) | Token::Lifetime(_) => true,
         _ => false,
     }
 }
@@ -895,6 +960,7 @@ fn next_space(tok: &Token) -> SpaceState {
 
     match *tok {
         Token::Not
+        | Token::BinOp(BinOpToken::And)
         | Token::Tilde
         | Token::At
         | Token::Comma
@@ -903,9 +969,7 @@ fn next_space(tok: &Token) -> SpaceState {
         | Token::DotDotDot
         | Token::DotDotEq
         | Token::DotEq
-        | Token::Question
-        | Token::Underscore
-        | Token::BinOp(_) => SpaceState::Punctuation,
+        | Token::Question => SpaceState::Punctuation,
 
         Token::ModSep
         | Token::Pound
@@ -914,7 +978,7 @@ fn next_space(tok: &Token) -> SpaceState {
         | Token::CloseDelim(_)
         | Token::Whitespace => SpaceState::Never,
 
-        Token::Literal(..) | Token::Ident(_) | Token::Lifetime(_) => SpaceState::Ident,
+        Token::Literal(..) | Token::Ident(..) | Token::Lifetime(_) => SpaceState::Ident,
 
         _ => SpaceState::Always,
     }
@@ -924,7 +988,7 @@ fn next_space(tok: &Token) -> SpaceState {
 /// 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 &format!("{}", mac.node.path) == "try" {
         let ts: TokenStream = mac.node.tts.clone().into();
         let mut parser = new_parser_from_tts(context.parse_session, ts.trees().collect());
 
@@ -939,18 +1003,18 @@ pub fn convert_try_mac(mac: &ast::Mac, context: &RewriteContext) -> Option<ast::
     }
 }
 
-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
+        DelimToken::Brace
     }
 }
 
@@ -987,37 +1051,47 @@ fn indent_macro_snippet(
     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 lines = LineClasses::new(macro_str);
+    let first_line = lines.next().map(|(_, s)| s.trim_right().to_owned())?;
     let mut trimmed_lines = Vec::with_capacity(16);
 
+    let mut veto_trim = false;
     let min_prefix_space_width = lines
-        .filter_map(|line| {
-            let prefix_space_width = if is_empty_line(line) {
+        .filter_map(|(kind, line)| {
+            let mut trimmed = true;
+            let prefix_space_width = if is_empty_line(&line) {
                 None
             } else {
-                Some(get_prefix_space_width(context, line))
+                Some(get_prefix_space_width(context, &line))
             };
-            trimmed_lines.push((line.trim(), prefix_space_width));
+            let line = if veto_trim || (kind.is_string() && !line.ends_with('\\')) {
+                veto_trim = kind.is_string() && !line.ends_with('\\');
+                trimmed = false;
+                line
+            } else {
+                line.trim().to_owned()
+            };
+            trimmed_lines.push((trimmed, line, prefix_space_width));
             prefix_space_width
         })
         .min()?;
 
     Some(
-        String::from(first_line) + "\n"
+        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(),
-                })
+                .map(
+                    |&(trimmed, ref line, prefix_space_width)| match prefix_space_width {
+                        _ if !trimmed => line.to_owned(),
+                        Some(original_indent_width) => {
+                            let new_indent_width = indent.width()
+                                + original_indent_width.saturating_sub(min_prefix_space_width);
+                            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"),
     )
@@ -1164,15 +1238,17 @@ fn rewrite(
 
         // 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"
-            });
+        let mut new_body = LineClasses::new(new_body.trim_right())
+            .fold(
+                (String::new(), true),
+                |(mut s, need_indent), (kind, ref l)| {
+                    if !l.is_empty() && need_indent {
+                        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.
@@ -1213,7 +1289,9 @@ fn rewrite(
 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());
+    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));