From a2f861730e5b33391c97fe7ec91470d1c9b96ba9 Mon Sep 17 00:00:00 2001
From: moe <35686186+csmoe@users.noreply.github.com>
Date: Thu, 8 Mar 2018 17:05:39 +0800
Subject: [PATCH] fix adds a trailing comma to struct-like macro (#2490)
* fix adds a trailing comma to struct-like macro
---
src/expr.rs | 39 +++++++++++++++++++++++++-------------
tests/source/issue-2445.rs | 21 ++++++++++++++++++++
tests/target/issue-2445.rs | 21 ++++++++++++++++++++
3 files changed, 68 insertions(+), 13 deletions(-)
create mode 100644 tests/source/issue-2445.rs
create mode 100644 tests/target/issue-2445.rs
diff --git a/src/expr.rs b/src/expr.rs
index 2945f03a535..481baa80de6 100644
--- a/src/expr.rs
+++ b/src/expr.rs
@@ -20,7 +20,7 @@ use chains::rewrite_chain;
use closures;
use codemap::{LineRangeUtils, SpanUtils};
use comment::{combine_strs_with_missing_comments, contains_comment, recover_comment_removed,
- rewrite_comment, rewrite_missing_comment, FindUncommented};
+ rewrite_comment, rewrite_missing_comment, CharClasses, FindUncommented};
use config::{Config, ControlBraceStyle, IndentStyle};
use lists::{definitive_tactic, itemize_list, shape_for_tactic, struct_lit_formatting,
struct_lit_shape, struct_lit_tactic, write_list, ListFormatting, ListItem, Separator};
@@ -2411,20 +2411,20 @@ pub fn wrap_args_with_parens(
/// trailing comma. This function is used when rewriting macro, as adding or removing a trailing
/// comma from macro can potentially break the code.
fn span_ends_with_comma(context: &RewriteContext, span: Span) -> bool {
- let mut encountered_closing_paren = false;
- for c in context.snippet(span).chars().rev() {
+ let mut result: bool = Default::default();
+ let mut prev_char: char = Default::default();
+
+ for (kind, c) in CharClasses::new(context.snippet(span).chars()) {
match c {
- ',' => return true,
- ')' => if encountered_closing_paren {
- return false;
- } else {
- encountered_closing_paren = true;
- },
- _ if c.is_whitespace() => continue,
- _ => return false,
+ _ if kind.is_comment() || c.is_whitespace() => continue,
+ ')' | '}' => result = result && prev_char != c,
+ ',' => result = true,
+ _ => result = false,
}
+ prev_char = c;
}
- false
+
+ result
}
fn rewrite_paren(context: &RewriteContext, subexpr: &ast::Expr, shape: Shape) -> Option<String> {
@@ -2608,7 +2608,20 @@ fn rewrite_struct_lit<'a>(
let tactic = struct_lit_tactic(h_shape, context, &item_vec);
let nested_shape = shape_for_tactic(tactic, h_shape, v_shape);
- let fmt = struct_lit_formatting(nested_shape, tactic, context, base.is_some());
+
+ let ends_with_comma = span_ends_with_comma(context, span);
+ let force_no_trailing_comma = if context.inside_macro && !ends_with_comma {
+ true
+ } else {
+ false
+ };
+
+ let fmt = struct_lit_formatting(
+ nested_shape,
+ tactic,
+ context,
+ force_no_trailing_comma || base.is_some(),
+ );
write_list(&item_vec, &fmt)?
};
diff --git a/tests/source/issue-2445.rs b/tests/source/issue-2445.rs
new file mode 100644
index 00000000000..84ce6e647b8
--- /dev/null
+++ b/tests/source/issue-2445.rs
@@ -0,0 +1,21 @@
+test!(RunPassPretty {
+ // comment
+ path: "src/test/run-pass/pretty",
+ mode: "pretty",
+ suite: "run-pass",
+ default: false,
+ host: true // should, force, , no trailing comma here
+});
+
+test!(RunPassPretty {
+ // comment
+ path: "src/test/run-pass/pretty",
+ mode: "pretty",
+ suite: "run-pass",
+ default: false,
+ host: true, // should, , preserve, the trailing comma
+});
+
+test!(Test{
+ field: i32, // comment
+});
diff --git a/tests/target/issue-2445.rs b/tests/target/issue-2445.rs
new file mode 100644
index 00000000000..1bc7752fd16
--- /dev/null
+++ b/tests/target/issue-2445.rs
@@ -0,0 +1,21 @@
+test!(RunPassPretty {
+ // comment
+ path: "src/test/run-pass/pretty",
+ mode: "pretty",
+ suite: "run-pass",
+ default: false,
+ host: true // should, force, , no trailing comma here
+});
+
+test!(RunPassPretty {
+ // comment
+ path: "src/test/run-pass/pretty",
+ mode: "pretty",
+ suite: "run-pass",
+ default: false,
+ host: true, // should, , preserve, the trailing comma
+});
+
+test!(Test {
+ field: i32, // comment
+});