<commit_before>// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

// Format list-like macro invocations. These are invocations whose token trees
// can be interpreted as expressions and separated by commas.
// Note that these token trees do not actually have to be interpreted as
// expressions by the compiler. An example of an invocation we would reformat is
// foo!( x, y, z ). The token x may represent an identifier in the code, but we
// interpreted as an expression.
// Macro uses which are not-list like, such as bar!(key => val), will not be
// reformated.
// List-like invocations with parentheses will be formatted as function calls,
// and those with brackets will be formatted as array literals.

use std::thread;

use syntax::ast;
use syntax::parse::token::{Eof, Comma, Token};
use syntax::parse::{ParseSess, tts_to_parser};

use Indent;
use rewrite::RewriteContext;
use expr::{rewrite_call, rewrite_array};
use comment::FindUncommented;
use utils::wrap_str;

// We need to pass `TokenTree`s to our expression parsing thread, but they are
// not `Send`. We wrap them in a `Send` container to force our will.
// FIXME: this is a pretty terrible hack. Any other solution would be preferred.
struct ForceSend<T>(pub T);
unsafe impl<T> Send for ForceSend<T> {}

// FIXME: use the enum from libsyntax?
enum MacroStyle {
    Parens,
    Brackets,
    Braces,
}

pub fn rewrite_macro(mac: &ast::Mac,
                     context: &RewriteContext,
                     width: usize,
                     offset: Indent)
                     -> Option<String> {
    let style = macro_style(mac, context);
    let macro_name = format!("{}!", mac.node.path);

    if let MacroStyle::Braces = style {
        return None;
    } else if mac.node.tts.is_empty() {
        return if let MacroStyle::Parens = style {
            Some(format!("{}()", macro_name))
        } else {
            Some(format!("{}[]", macro_name))
        };
    }

    let wrapped_tt_vec = ForceSend(mac.node.tts.clone());
    // Wrap expression parsing logic in a thread since the libsyntax parser
    // panicks on failure, which we do not want to propagate.
    let expr_vec_result = thread::catch_panic(move || {
        let parse_session = ParseSess::new();
        let mut parser = tts_to_parser(&parse_session, wrapped_tt_vec.0, vec![]);
        let mut expr_vec = vec![];

        loop {
            expr_vec.push(parser.parse_expr());

            match parser.token {
                Token::Eof => break,
                Token::Comma => (),
                _ => panic!("Macro not list-like, skiping..."),
            }

            let _ = parser.bump();
        }

        expr_vec
    });
    let expr_vec = try_opt!(expr_vec_result.ok());

    match style {
        MacroStyle::Parens => {
            // Format macro invocation as function call.
            rewrite_call(context, &macro_name, &expr_vec, mac.span, width, offset)
        }<commit_msg>Prevent panics on list-like macro uses with trailing commas<commit_after>// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

// Format list-like macro invocations. These are invocations whose token trees
// can be interpreted as expressions and separated by commas.
// Note that these token trees do not actually have to be interpreted as
// expressions by the compiler. An example of an invocation we would reformat is
// foo!( x, y, z ). The token x may represent an identifier in the code, but we
// interpreted as an expression.
// Macro uses which are not-list like, such as bar!(key => val), will not be
// reformated.
// List-like invocations with parentheses will be formatted as function calls,
// and those with brackets will be formatted as array literals.

use std::thread;

use syntax::ast;
use syntax::parse::token::{Eof, Comma, Token};
use syntax::parse::{ParseSess, tts_to_parser};

use Indent;
use rewrite::RewriteContext;
use expr::{rewrite_call, rewrite_array};
use comment::FindUncommented;
use utils::wrap_str;

// We need to pass `TokenTree`s to our expression parsing thread, but they are
// not `Send`. We wrap them in a `Send` container to force our will.
// FIXME: this is a pretty terrible hack. Any other solution would be preferred.
struct ForceSend<T>(pub T);
unsafe impl<T> Send for ForceSend<T> {}

// FIXME: use the enum from libsyntax?
enum MacroStyle {
    Parens,
    Brackets,
    Braces,
}

pub fn rewrite_macro(mac: &ast::Mac,
                     context: &RewriteContext,
                     width: usize,
                     offset: Indent)
                     -> Option<String> {
    let style = macro_style(mac, context);
    let macro_name = format!("{}!", mac.node.path);

    if let MacroStyle::Braces = style {
        return None;
    } else if mac.node.tts.is_empty() {
        return if let MacroStyle::Parens = style {
            Some(format!("{}()", macro_name))
        } else {
            Some(format!("{}[]", macro_name))
        };
    }

    let wrapped_tt_vec = ForceSend(mac.node.tts.clone());
    // Wrap expression parsing logic in a thread since the libsyntax parser
    // panics on failure, which we do not want to propagate.
    // The expression vector is wrapped in an Option inside a Result.
    let expr_vec_result = thread::catch_panic(move || {
        let parse_session = ParseSess::new();
        let mut parser = tts_to_parser(&parse_session, wrapped_tt_vec.0, vec![]);
        let mut expr_vec = vec![];

        loop {
            expr_vec.push(parser.parse_expr());

            match parser.token {
                Token::Eof => break,
                Token::Comma => (),
                _ => panic!("Macro not list-like, skiping..."),
            }

            let _ = parser.bump();

            if parser.token == Token::Eof {
                return None;
            }
        }

        Some(expr_vec)
    });
    let expr_vec = try_opt!(try_opt!(expr_vec_result.ok()));

    match style {
        MacroStyle::Parens => {
            // Format macro invocation as function call.
            rewrite_call(context, &macro_name, &expr_vec, mac.span, width, offset)
        }
{'fraction_non_alphanumeric': 0.11178422039521131, 'fraction_numerical': 0.0025962786672436176, 'mean_word_length': 2.602077922077922, 'pattern_counts': {'":': 0, '<': 15, '<?xml version=': 0, '>': 27, 'https://': 0, 'lorem ipsum': 0, 'www.': 2, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 2, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
{'dir': 'git-commits-cleaned', 'id': '292890', 'n_tokens_mistral': 2028, 'n_tokens_neox': 1948, 'n_words': 712}