can #line directive dynamically resolve the file path?

[asmwarrior]

On 2010-12-26 11:17, Jeffrey Walton wrote:
> On Sat, Dec 25, 2010 at 10:00 PM, asmwarrior<asmwarrior@gmail.com>  wrote:
>> Hi, I have a question about #line directive. I have two files. a.c and b.c
>> under my c:/ (I use Windows MinGW)
>>
>> Now, I have a.c
>> ---------------------------------------------
>> int main()
>> {
>>   #line 1 "b.c"
>>   int a
>>   return 0;
>> }
>> ---------------------------------------------
>> and b.c
>> ---------------------------------------------
>> int f1()
>> {
>>   return 0;
>> }
>> ---------------------------------------------
>>
>>
>> Now, I try to run the command line:
>>
>> C:\>gcc -c C:\a.c
>> b.c: In function 'main':
>> b.c:2:3: error: expected '=', ',', ';', 'asm' or '__attribute__' before
>> 'return'
>> C:\>
>>
>> You can see, the gcc report error says there are some error in "b.c" but not
>> "c:\b.c".
>> which means gcc can not dynamically resolve the file path after the #line
>> directive.
>>
>> Though I can hard-coded the "c:/b.c" to the a.c file, but this is not a good
>> solution because I would always move the code to other place.
>>
>> My question is: Can any one give me an idea to solve this kind of problem?
>> thanks.
>>
>>
>> One reference is:
>> http://gcc.gnu.org/onlinedocs/cpp/Line-Control.html#Line-Control
> Writing a parser generator?
Thanks for your reply!!

Correct, in-fact, I'm using QUEX lexical lexer generator:
https://sourceforge.net/projects/quex/

And my question comes the case that I would like to distribute the 
generated lexer code with the Quex code base. But the lexer code 
contains a lot of #line directive which reference to Quex code base.

see the discussion here:
https://sourceforge.net/projects/quex/forums/forum/574343/topic/4001340?message=8948936

> Try __LINE__ and __FILE__ instead.
> http://gcc.gnu.org/onlinedocs/cpp/Standard-Predefined-Macros.html
>
> Jeff
Did you mean that I just do some thing like this?

instead of write

#line 1 "c:/b.c"

I need to write like:

#define __LINE__ "c:/b.c"
#define __LINE__ 1

Am I right?

thanks

asmwarrior