Merge pull request rust-lang#1937 from topecongiro/enhance-macro-rewrite

Enhance macro rewrite

Author: nrc

src/expr.rs

@@ -26,7 +26,7 @@ use items::{span_hi_for_arg, span_lo_for_arg};
 use lists::{definitive_tactic, itemize_list, shape_for_tactic, struct_lit_formatting,
             struct_lit_shape, struct_lit_tactic, write_list, DefinitiveListTactic, ListFormatting,
             ListItem, ListTactic, Separator, SeparatorPlace, SeparatorTactic};
-use macros::{rewrite_macro, MacroPosition};
+use macros::{rewrite_macro, MacroArg, MacroPosition};
 use patterns::{can_be_overflowed_pat, TuplePatField};
 use rewrite::{Rewrite, RewriteContext};
 use string::{rewrite_string, StringFormat};
@@ -3012,3 +3012,20 @@ impl<'a> ToExpr for ast::StructField {
         false
     }
 }
+
+impl<'a> ToExpr for MacroArg {
+    fn to_expr(&self) -> Option<&ast::Expr> {
+        match self {
+            &MacroArg::Expr(ref expr) => Some(expr),
+            _ => None,
+        }
+    }
+
+    fn can_be_overflowed(&self, context: &RewriteContext, len: usize) -> bool {
+        match self {
+            &MacroArg::Expr(ref expr) => can_be_overflowed_expr(context, expr, len),
+            &MacroArg::Ty(ref ty) => can_be_overflowed_type(context, ty, len),
+            &MacroArg::Pat(..) => false,
+        }
+    }
+}

src/lib.rs

@@ -34,6 +34,7 @@ use std::rc::Rc;
 
 use errors::{DiagnosticBuilder, Handler};
 use errors::emitter::{ColorConfig, EmitterWriter};
+use macros::MacroArg;
 use strings::string_buffer::StringBuffer;
 use syntax::ast;
 use syntax::codemap::{CodeMap, FilePathMapping, Span};
@@ -216,6 +217,16 @@ impl Spanned for ast::TyParamBound {
     }
 }
 
+impl Spanned for MacroArg {
+    fn span(&self) -> Span {
+        match *self {
+            MacroArg::Expr(ref expr) => expr.span(),
+            MacroArg::Ty(ref ty) => ty.span(),
+            MacroArg::Pat(ref pat) => pat.span(),
+        }
+    }
+}
+
 #[derive(Copy, Clone, Debug)]
 pub struct Indent {
     // Width of the block indent, in characters. Must be a multiple of
@@ -682,7 +693,6 @@ fn format_ast<F>(
     parse_session: &mut ParseSess,
     main_file: &Path,
     config: &Config,
-    codemap: &Rc<CodeMap>,
     mut after_file: F,
 ) -> Result<(FileMap, bool), io::Error>
 where
@@ -703,29 +713,19 @@ where
         if config.verbose() {
             println!("Formatting {}", path_str);
         }
-        {
-            let mut visitor = FmtVisitor::from_codemap(parse_session, config);
-            let filemap = visitor.codemap.lookup_char_pos(module.inner.lo()).file;
-            // Format inner attributes if available.
-            if !krate.attrs.is_empty() && path == main_file {
-                visitor.visit_attrs(&krate.attrs, ast::AttrStyle::Inner);
-            } else {
-                visitor.last_pos = filemap.start_pos;
-            }
-            visitor.format_separate_mod(module, &*filemap);
+        let mut visitor = FmtVisitor::from_codemap(parse_session, config);
+        let filemap = visitor.codemap.lookup_char_pos(module.inner.lo()).file;
+        // Format inner attributes if available.
+        if !krate.attrs.is_empty() && path == main_file {
+            visitor.visit_attrs(&krate.attrs, ast::AttrStyle::Inner);
+        } else {
+            visitor.last_pos = filemap.start_pos;
+        }
+        visitor.format_separate_mod(module, &*filemap);
 
-            has_diff |= after_file(path_str, &mut visitor.buffer)?;
+        has_diff |= after_file(path_str, &mut visitor.buffer)?;
 
-            result.push((path_str.to_owned(), visitor.buffer));
-        }
-        // Reset the error count.
-        if parse_session.span_diagnostic.has_errors() {
-            let silent_emitter = Box::new(EmitterWriter::new(
-                Box::new(Vec::new()),
-                Some(codemap.clone()),
-            ));
-            parse_session.span_diagnostic = Handler::with_emitter(true, false, silent_emitter);
-        }
+        result.push((path_str.to_owned(), visitor.buffer));
     }
 
     Ok((result, has_diff))
@@ -912,7 +912,6 @@ pub fn format_input<T: Write>(
         &mut parse_session,
         &main_file,
         config,
-        &codemap,
         |file_name, file| {
             // For some reason, the codemap does not include terminating
             // newlines so we must add one on for each file. This is sad.

src/macros.rs

@@ -22,6 +22,7 @@
 use syntax::ast;
 use syntax::codemap::BytePos;
 use syntax::parse::new_parser_from_tts;
+use syntax::parse::parser::Parser;
 use syntax::parse::token::Token;
 use syntax::symbol;
 use syntax::tokenstream::TokenStream;
@@ -61,6 +62,51 @@ impl MacroStyle {
     }
 }
 
+pub enum MacroArg {
+    Expr(ast::Expr),
+    Ty(ast::Ty),
+    Pat(ast::Pat),
+}
+
+impl Rewrite for MacroArg {
+    fn rewrite(&self, context: &RewriteContext, shape: Shape) -> Option<String> {
+        match self {
+            &MacroArg::Expr(ref expr) => expr.rewrite(context, shape),
+            &MacroArg::Ty(ref ty) => ty.rewrite(context, shape),
+            &MacroArg::Pat(ref pat) => pat.rewrite(context, shape),
+        }
+    }
+}
+
+fn parse_macro_arg(parser: &mut Parser) -> Option<MacroArg> {
+    macro_rules! parse_macro_arg {
+        ($target:tt, $macro_arg:ident, $parser:ident) => {
+            let mut cloned_parser = (*parser).clone();
+            match cloned_parser.$parser() {
+                Ok($target) => {
+                    if parser.sess.span_diagnostic.has_errors() {
+                        parser.sess.span_diagnostic.reset_err_count();
+                    } else {
+                        // Parsing succeeded.
+                        *parser = cloned_parser;
+                        return Some(MacroArg::$macro_arg((*$target).clone()));
+                    }
+                }
+                Err(mut e) => {
+                    e.cancel();
+                    parser.sess.span_diagnostic.reset_err_count();
+                }
+            }
+        }
+    }
+
+    parse_macro_arg!(expr, Expr, parse_expr);
+    parse_macro_arg!(ty, Ty, parse_ty);
+    parse_macro_arg!(pat, Pat, parse_pat);
+
+    return None;
+}
+
 pub fn rewrite_macro(
     mac: &ast::Mac,
     extra_ident: Option<ast::Ident>,
@@ -93,7 +139,7 @@ pub fn rewrite_macro(
         original_style
     };
 
-    let ts: TokenStream = mac.node.tts.clone().into();
+    let ts: TokenStream = mac.node.stream();
     if ts.is_empty() && !contains_comment(&context.snippet(mac.span)) {
         return match style {
             MacroStyle::Parens if position == MacroPosition::Item => {
@@ -106,32 +152,16 @@ pub fn rewrite_macro(
     }
 
     let mut parser = new_parser_from_tts(context.parse_session, ts.trees().collect());
-    let mut expr_vec = Vec::new();
+    let mut arg_vec = Vec::new();
     let mut vec_with_semi = false;
     let mut trailing_comma = false;
 
     if MacroStyle::Braces != style {
         loop {
-            let expr = match parser.parse_expr() {
-                Ok(expr) => {
-                    // Recovered errors.
-                    if context.parse_session.span_diagnostic.has_errors() {
-                        return indent_macro_snippet(
-                            context,
-                            &context.snippet(mac.span),
-                            shape.indent,
-                        );
-                    }
-
-                    expr
-                }
-                Err(mut e) => {
-                    e.cancel();
-                    return indent_macro_snippet(context, &context.snippet(mac.span), shape.indent);
-                }
-            };
-
-            expr_vec.push(expr);
+            match parse_macro_arg(&mut parser) {
+                Some(arg) => arg_vec.push(arg),
+                None => return Some(context.snippet(mac.span)),
+            }
 
             match parser.token {
                 Token::Eof => break,
@@ -141,25 +171,22 @@ pub fn rewrite_macro(
                     if FORCED_BRACKET_MACROS.contains(&&macro_name[..]) {
                         parser.bump();
                         if parser.token != Token::Eof {
-                            match parser.parse_expr() {
-                                Ok(expr) => {
-                                    if context.parse_session.span_diagnostic.has_errors() {
-                                        return None;
-                                    }
-                                    expr_vec.push(expr);
+                            match parse_macro_arg(&mut parser) {
+                                Some(arg) => {
+                                    arg_vec.push(arg);
                                     parser.bump();
-                                    if parser.token == Token::Eof && expr_vec.len() == 2 {
+                                    if parser.token == Token::Eof && arg_vec.len() == 2 {
                                         vec_with_semi = true;
                                         break;
                                     }
                                 }
-                                Err(mut e) => e.cancel(),
+                                None => return Some(context.snippet(mac.span)),
                             }
                         }
                     }
-                    return None;
+                    return Some(context.snippet(mac.span));
                 }
-                _ => return None,
+                _ => return Some(context.snippet(mac.span)),
             }
 
             parser.bump();
@@ -178,7 +205,7 @@ pub fn rewrite_macro(
             let rw = rewrite_call_inner(
                 context,
                 &macro_name,
-                &expr_vec.iter().map(|e| &**e).collect::<Vec<_>>()[..],
+                &arg_vec.iter().map(|e| &*e).collect::<Vec<_>>()[..],
                 mac.span,
                 shape,
                 context.config.fn_call_width(),
@@ -201,8 +228,8 @@ pub fn rewrite_macro(
                 // 6 = `vec!` + `; `
                 let total_overhead = lbr.len() + rbr.len() + 6;
                 let nested_shape = mac_shape.block_indent(context.config.tab_spaces());
-                let lhs = try_opt!(expr_vec[0].rewrite(context, nested_shape));
-                let rhs = try_opt!(expr_vec[1].rewrite(context, nested_shape));
+                let lhs = try_opt!(arg_vec[0].rewrite(context, nested_shape));
+                let rhs = try_opt!(arg_vec[1].rewrite(context, nested_shape));
                 if !lhs.contains('\n') && !rhs.contains('\n') &&
                     lhs.len() + rhs.len() + total_overhead <= shape.width
                 {
@@ -228,14 +255,26 @@ pub fn rewrite_macro(
                     context.inside_macro = false;
                     trailing_comma = false;
                 }
+                // Convert `MacroArg` into `ast::Expr`, as `rewrite_array` only accepts the latter.
+                let expr_vec: Vec<_> = arg_vec
+                    .iter()
+                    .filter_map(|e| match *e {
+                        MacroArg::Expr(ref e) => Some(e.clone()),
+                        _ => None,
+                    })
+                    .collect();
+                if expr_vec.len() != arg_vec.len() {
+                    return Some(context.snippet(mac.span));
+                }
+                let sp = mk_sp(
+                    context
+                        .codemap
+                        .span_after(mac.span, original_style.opener()),
+                    mac.span.hi() - BytePos(1),
+                );
                 let rewrite = try_opt!(rewrite_array(
-                    expr_vec.iter().map(|x| &**x),
-                    mk_sp(
-                        context
-                            .codemap
-                            .span_after(mac.span, original_style.opener()),
-                        mac.span.hi() - BytePos(1),
-                    ),
+                    expr_vec.iter(),
+                    sp,
                     context,
                     mac_shape,
                     trailing_comma,

tests/source/macros.rs

@@ -164,9 +164,6 @@ fn issue_1921() {
 }
 }
 
-// Put the following tests with macro invocations whose arguments cannot be parsed as expressioins
-// at the end of the file for now.
-
 // #1577
 fn issue1577() {
     let json = json!({
@@ -178,3 +175,17 @@ gfx_pipeline!(pipe {
     vbuf: gfx::VertexBuffer<Vertex> = (),
     out: gfx::RenderTarget<ColorFormat> = "Target0",
 });
+
+// #1919
+#[test]
+fn __bindgen_test_layout_HandleWithDtor_open0_int_close0_instantiation() {
+    assert_eq!(
+        ::std::mem::size_of::<HandleWithDtor<::std::os::raw::c_int>>(),
+        8usize,
+        concat!(
+            "Size of template specialization: ",
+            stringify ! ( HandleWithDtor < :: std :: os :: raw :: c_int > )
+        )
+    );
+    assert_eq ! ( :: std :: mem :: align_of :: < HandleWithDtor < :: std :: os :: raw :: c_int > > ( ) , 8usize , concat ! ( "Alignment of template specialization: " , stringify ! ( HandleWithDtor < :: std :: os :: raw :: c_int > ) ) );
+}

tests/target/macros.rs

@@ -208,9 +208,6 @@ fn issue_1921() {
     }
 }
 
-// Put the following tests with macro invocations whose arguments cannot be parsed as expressioins
-// at the end of the file for now.
-
 // #1577
 fn issue1577() {
     let json = json!({
@@ -222,3 +219,24 @@ gfx_pipeline!(pipe {
     vbuf: gfx::VertexBuffer<Vertex> = (),
     out: gfx::RenderTarget<ColorFormat> = "Target0",
 });
+
+// #1919
+#[test]
+fn __bindgen_test_layout_HandleWithDtor_open0_int_close0_instantiation() {
+    assert_eq!(
+        ::std::mem::size_of::<HandleWithDtor<::std::os::raw::c_int>>(),
+        8usize,
+        concat!(
+            "Size of template specialization: ",
+            stringify!(HandleWithDtor<::std::os::raw::c_int>)
+        )
+    );
+    assert_eq!(
+        ::std::mem::align_of::<HandleWithDtor<::std::os::raw::c_int>>(),
+        8usize,
+        concat!(
+            "Alignment of template specialization: ",
+            stringify!(HandleWithDtor<::std::os::raw::c_int>)
+        )
+    );
+}