[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Emacs-diffs] emacs-25 326ffcc: Allow line comments ending with escaped
From: |
Alan Mackenzie |
Subject: |
[Emacs-diffs] emacs-25 326ffcc: Allow line comments ending with escaped NL to be continued to the next line. |
Date: |
Mon, 28 Dec 2015 16:00:35 +0000 |
branch: emacs-25
commit 326ffcce5fbbb0ca368cfa08a33101dbbcaa2ace
Author: Alan Mackenzie <address@hidden>
Commit: Alan Mackenzie <address@hidden>
Allow line comments ending with escaped NL to be continued to the next line.
Use this in C, C++, and Objective C Modes. Fixes bug#22246
* src/syntax.c (comment-end-can-be-escaped): New buffer local variable.
(forw-comment, back-comment): On encountering an end of comment character,
test whether it is escaped when `comment-end-can-be-escaped' is non-nil.
* doc/lispref/syntax.texi (Control Parsing): Describe
`comment-end-can-be-escaped'.
* etc/NEWS (Lisp Changes): Describe `comment-end-can-be-escaped'.
* lisp/progmodes/cc-langs.el: New c-lang-setvar
`comment-end-can-be-escaped'.
---
doc/lispref/syntax.texi | 8 ++++++++
etc/NEWS | 5 +++++
lisp/progmodes/cc-langs.el | 8 ++++++++
src/syntax.c | 15 ++++++++++++---
4 files changed, 33 insertions(+), 3 deletions(-)
diff --git a/doc/lispref/syntax.texi b/doc/lispref/syntax.texi
index 7a984e3..831ebd1 100644
--- a/doc/lispref/syntax.texi
+++ b/doc/lispref/syntax.texi
@@ -945,6 +945,14 @@ whitespace by the functions in this section and by
@code{forward-sexp},
The behavior of @code{parse-partial-sexp} is also affected by
@code{parse-sexp-lookup-properties} (@pxref{Syntax Properties}).
address@hidden comment-end-can-be-escaped
+If this buffer local variable is address@hidden, a single character
+which usually terminates a comment doesn't do so when that character
+is escaped. This is used in C and C++ Modes, where line comments
+starting with @samp{//} can be continued onto the next line by
+escaping the newline with @samp{\}.
address@hidden defvar
+
You can use @code{forward-comment} to move forward or backward over
one comment or several comments.
diff --git a/etc/NEWS b/etc/NEWS
index 1aeab35..3b86a88 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -1268,6 +1268,11 @@ Area. The output is still logged to the *Messages*
buffer.
buffers to allow certain parts of the text to be writable.
+++
+** A new variable `comment-end-can-be-escaped' is useful in languages
+ such as C and C++ where line comments with escaped newlines are
+ continued to the next line.
+
++++
** New macro `define-advice'.
** `read-buffer' takes a new `predicate' argument.
diff --git a/lisp/progmodes/cc-langs.el b/lisp/progmodes/cc-langs.el
index 5b67083..1a07c4c 100644
--- a/lisp/progmodes/cc-langs.el
+++ b/lisp/progmodes/cc-langs.el
@@ -1433,6 +1433,14 @@ properly."
"\\)\\s *"))
(c-lang-setvar comment-start-skip (c-lang-const comment-start-skip))
+(c-lang-defconst comment-end-can-be-escaped
+ "When non-nil, escaped EOLs inside comments are valid.
+This works in Emacs >= 25.1."
+ t nil
+ (c c++ objc) t)
+(c-lang-setvar comment-end-can-be-escaped
+ (c-lang-const comment-end-can-be-escaped))
+
(c-lang-defconst c-syntactic-ws-start
;; Regexp matching any sequence that can start syntactic whitespace.
;; The only uncertain case is '#' when there are cpp directives.
diff --git a/src/syntax.c b/src/syntax.c
index 5b0ec6d..2acbd41 100644
--- a/src/syntax.c
+++ b/src/syntax.c
@@ -790,8 +790,10 @@ back_comment (ptrdiff_t from, ptrdiff_t from_byte,
ptrdiff_t stop,
|| SYNTAX_FLAGS_COMMENT_NESTED (syntax) != comnested))
continue;
- /* Ignore escaped characters, except comment-enders. */
- if (code != Sendcomment && char_quoted (from, from_byte))
+ /* Ignore escaped characters, except comment-enders which cannot
+ be escaped. */
+ if ((Vcomment_end_can_be_escaped || code != Sendcomment)
+ && char_quoted (from, from_byte))
continue;
switch (code)
@@ -2346,7 +2348,8 @@ forw_comment (ptrdiff_t from, ptrdiff_t from_byte,
ptrdiff_t stop,
if (code == Sendcomment
&& SYNTAX_FLAGS_COMMENT_STYLE (syntax, 0) == style
&& (SYNTAX_FLAGS_COMMENT_NESTED (syntax) ?
- (nesting > 0 && --nesting == 0) : nesting < 0))
+ (nesting > 0 && --nesting == 0) : nesting < 0)
+ && !(Vcomment_end_can_be_escaped && char_quoted (from, from_byte)))
/* We have encountered a comment end of the same style
as the comment sequence which began this comment
section. */
@@ -3702,6 +3705,12 @@ character of that word.
In both cases, LIMIT bounds the search. */);
Vfind_word_boundary_function_table = Fmake_char_table (Qnil, Qnil);
+ DEFVAR_BOOL ("comment-end-can-be-escaped", Vcomment_end_can_be_escaped,
+ doc: /* Non-nil means an escaped ender inside a comment
doesn'tend the comment. */);
+ Vcomment_end_can_be_escaped = 0;
+ DEFSYM (Qcomment_end_can_be_escaped, "comment-end-can-be-escaped");
+ Fmake_variable_buffer_local (Qcomment_end_can_be_escaped);
+
defsubr (&Ssyntax_table_p);
defsubr (&Ssyntax_table);
defsubr (&Sstandard_syntax_table);
[Prev in Thread] |
Current Thread |
[Next in Thread] |
- [Emacs-diffs] emacs-25 326ffcc: Allow line comments ending with escaped NL to be continued to the next line.,
Alan Mackenzie <=