This small code snippet can reproduce the bug :

#include <stdio.h>

int
main (int argv, char *argc)
{
	char *test;

	test = "foo\n"; // \\
	test = "bar\n";
	
	printf(test);
}

[sf:antea] tmp $ gcc test-bug.c
[sf:antea] tmp $ ./a.out
foo

Anyway, it should be tested with other compilers than gcc before confirming, since it could as well be a gcc bug. (this is a corner case and it seems weird to me that the C standard envisages such a behaviour)

This is not a bug, it is a consequence of a GCC convenience add-on. //-style comments are part of C++, not ANSI C. GCC supports using them, however, and thus compiles the testcases. Adding -pedantic -ansi compiler flags to enforce the standard will cause this testcode to fail. Additionally, an escaping backslash is not supposed to have anything follow it except a newline.

Just change

test = "foo\n"; // \\
test = "bar\n";

to

test = "foo\n"; // \
test = "bar\n";

to highlight it the way GCC is seeing it. If you want proof that escaping backslashes aren't supposed to have anything follow them, try to compile this:

#define FOOBARBAZ  "foo" \ /* this comment will error */
        "bar" \
        "baz"

int main()
{
        printf(FOOBARBAZ);
        return 0;
}

Remove the /* */ comment and try it again. Works all of a sudden, eh? Add some whitespace after one of the escaped slashes and see if it gives you a warning like, "warning: backslash and newline separated by space."

> //-style comments are part of C++, not ANSI C.

Actually it is part of C now. Ever heard of C99 ?

fixed in the new highlighing engine