Re: [Tinycc-devel] tcc_add_symbol with macros

[David Mertens]

Hello Joel,

As I understand it, tcc_add_symbol only adds things that can be pointed to. In your case, gdispClear is not something that can be pointed to, it's just a macro, i.e. an instruction to the compiler on how to produce C code. Functions and global variables can be pointed to, so they are the appropriate targets for tcc_add_symbol. You should add those.

But, what exactly are you trying to accomplish? You probably want to provide the macro-exposed interface to consuming code. In that case, you could do the following one-two punch: add preprocessor definitions with tcc_define_symbol, and then add the symbol to the function itself with tcc_add_symbol. Also be sure to tcc_add_symbol GDISP. If you have to do this with a bunch of functions, you might consider wrapping that work in a script of some sort, but I leave that decision up to you. (If you work with Perl---and if you work with Cygwin then you should have Perl available---I'd be happy to figure out something, but I'd need a bit more information about the specific headers.)

David

On Thu, Jul 14, 2016 at 1:38 PM, Joel Bodenmann <address@hidden> wrote:

Hi folks,

 

I am using libtcc. So far everything is going smoothly. Now I’d like to make some “built-in” functions available to the program that is being compiled as shown with the add() function in the libtcc_test.c example. It works well with pure C functions, however, in my library that I would like to use I have functions and macros like this:

 

void gdispGClear(GDisplay* g, color_t color);

#define gdispClear(c) gdispGClear(GDISP, c)

 

void gdispGDrawPixel(GDisplay* g, coord_t x, coord_t y, color_t color);

#define gdispDrawPixel(x,y,c) gdispGDrawPixel(GDISP,x,y,c)

 

And so on… GDISP is a global variable in the file that declares those functions, something like a “default value”.

Using tcc_add_symbol() on the functions themselves (eg. gdispGClear()) works well, however, I’d like to use tcc_add_symbol() with gdispClear() instead. Sadly that doesn’t compile. I get the following error:

 

                ‘gdispClear’ undeclared (first use in this function)

 

I think that I understand why that doesn’t work. However, is there still a workaround to get this working?

 

 

Thank you for your help & best regards,

~ Joel

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