Added support for keeping comments

[dbartolini]

First preprocess pass now preserves comments so they can be returned later if requested. Since shaderc now has to deal with comments that may contain identifiers, a new strFindUncommented() has been introduced to only match strings when they appear outside C/C++ style comments.

One issue is that fcpp when used with FPPTAG_KEEPCOMMENTS gets confused on $input/output lines if those contain unspaced comments:

$ ./fcpp -C -V test_nosp.c 

#line 1 "test_nosp.c"
$input v_wpos, // comment
v_texcoord0
$input v_wpos, /* comment */v_texcoord0

$ cat test_nosp.c 
$input v_wpos, v_texcoord0// comment
$input v_wpos, v_texcoord0/* comment */

Adding a space fixes the issue:

$ ./fcpp -C -V test.c 

#line 1 "test.c"
$input v_wpos, v_texcoord0// comment

$input v_wpos, v_texcoord0/* comment */

$ cat test.c 
$input v_wpos, v_texcoord0 // comment
$input v_wpos, v_texcoord0 /* comment */

That is why fs_bump.sc has been changed. Not sure if you want this fixed and whether on fcpp or shaderc.

[bkaradzic]

Not sure if you want this fixed and whether on fcpp or shaderc.

It seems like fcpp issue, and it should be fixed there.

[bkaradzic]

Why not only keep them if keepComments is enabled?

[dbartolini]

Fixed.

[dbartolini]

Not sure if you want this fixed and whether on fcpp or shaderc.

It seems like fcpp issue, and it should be fixed there.

I'll fix it there and update this PR afterwards.