https://gcc.gnu.org/bugzilla/show_bug.cgi?id=8270
Kai Tietz <ktietz at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |ktietz at gcc dot gnu.org
--- Comment #55 from Kai Tietz <ktietz at gcc dot gnu.org> ---
Well, by looking into the standard ISO/IEC 9899:TC3 I found the following
statement:
5.1.12 Translation phase
"2. Each instance of a backslash character (\) immediately followed by a
new-line
character is deleted, splicing physical source lines to form logical source
lines.
Only the last backslash on any physical source line shall be eligible for being
part of such a splice. A source file that is not empty shall end in a new-line
character, which shall not be immediately preceded by a backslash character
before any such splicing takes place."
For ISO/IEC 14882:2003 we see at topic "2 Lexical Convention"
"2 Each instance of a new-line character and an immediately preceding backslash
character is deleted, splicing physical source lines to form logical source
lines. If, as a result, a character sequence that matches the syntax of a
universal-character-name is produced, the behavior is undefined. If a source
file that is not empty does not end in a new-line character, or ends in a
new-line character immediately preceded by a backslash character, the behavior
is undefined."
So the handling of backslash whitespace newline is clearly a gnu-extension and
not part of the standard.
I suggest something like this patch for fixing standard-requirement.
Additionally we could check here for cpp_option lang being gnu-style for
allowing 'backslash,whitespaces,newling' too.
Index: lex.c
===================================================================
--- lex.c (Revision 221514)
+++ lex.c (Arbeitskopie)
@@ -896,6 +896,11 @@ _cpp_clean_line (cpp_reader *pfile)
p--;
if (p - 1 != pbackslash)
goto done;
+ if (p != d)
+ {
+ ++p;
+ goto done;
+ }
/* Have an escaped newline; process it and proceed to
the slow path. */
@@ -917,13 +922,19 @@ _cpp_clean_line (cpp_reader *pfile)
if (s == buffer->rlimit)
break;
- /* Escaped? */
+ /* Escaped?
+ But make sure it isn't a backslash followed by a
+ whitespace. */
p = d;
while (p != buffer->next_line && is_nvspace (p[-1]))
p--;
if (p == buffer->next_line || p[-1] != '\\')
break;
-
+ if (p != d)
+ {
+ ++p;
+ break;
+ }
add_line_note (buffer, p - 1, p != d ? ' ': '\\');
d = p - 2;
buffer->next_line = p - 1;
