Difference between revisions of "Precompiler definitions"

Revision as of 23:08, 30 October 2005

Definitions

#define

Syntax: #define <defname>[(<macroparams>)] [<defvalue>]

Defines a precompiler define or macro.

<defname> contains the define name
<macroparams> contains a list of parameters, seperated by commas, to use with a macro (optional)
<defvalue> contains the define value (optional)

After statement parsing, <defname> is considered defined. Then, FTEQCC encounters <defname> or #<defname> during parsing, it will be replaced with <defvalue>, or <defname> will be erased if <defvalue> is not defined. If <macroparams> are defined, FTEQCC will use <defvalue> in the following fashion:

If a parameter in <macroparams> as an isolated token is found, it is replaced into the result.
If a parameter in <macroparams> is found with a preceding #, it is surrounded in quotes, then placed into the result.
If a parameter in <macroparams> is found with 2 preceding #, it is concatenated into the result.

Examples:

// Simple defines for use in precompiler control logic later on
#define MONSTERS
#define NEWWEAPONS

// Use of defines as constants
#define NEWWEAPONNAME "chainsaw with lasersight"
string s;
s = NEWWEAPONNAME; // Same as s = "chainsaw with lasersight";
s = #NEWWEAPONNAME; // Also same as s = "chainsaw with lasersight";

// Simple use of macros
#define ISEQUAL(a,b) (a == b)
float float1, float2;
if (float1 == float2)
   dosomething();
if (ISEQUAL(float1, float2)) // Does the same thing as the previous if
   dosomething();

// Use of stringify with macros
#define OBJECT(a) #a
string s;
s = OBJECT(mouse); // Same as s = "mouse";

// Use of concatenate with macros
#define SPECIALCLASS(a) float special_##a
SPECIALCLASS(thing); // same as float special_thing;

Warning: Macros are not the same as functions. For example:

float x;

#define SQRT(x) (x*x)
float squareroot (float x) { return x * x; }
float subtract2fromx (void) { x = x - 2; return x; }

void testfunction (void)
{
   x = 7; 
   y = squareroot(subtract2fromx()); // Results in (7-2) * (7-2) = 25

   x = 7;
   z = SQRT(subtract2fromx()); // Results in (7-2) * ((7-2)-2) = 15
}

#undef

Syntax: #undef <defname>

After statement parsing, <defname> is considered undefined. FTEQCC will no longer parse <defname> or #<defname> when it is encountered.

Control Logic

#ifdef

#ifndef

#if

#else

#endif

Something

#message

Syntax: #message <message>

#warning

Syntax: #warning <message>

#error

Syntax: #error <message>

File things

#include

Syntax: #include <file>

#includelist

Syntax: #includelist

#endlist

Syntax: #endlist

#output

Depreciated, use #pragma PROGS_DAT instead.

Second file things

#eof

Syntax: #eof

#forcecrc

Syntax: #forcecrc <crc>

#copyright

Depreciated, use #pragma COPYRIGHT instead.

#datafile

Syntax: #datafile <file>

#pack

#packid

Pragma (#pragma)

#pragma is an extensive precompiler statement which controls many aspects of the compiler.
Note that all unknown #pragma statements encountered by FTEQCC are ignored (with a warning.)

#pragma DONT_COMPILE_THIS_FILE

This pragma is parsed but ignored by FTEQCC so PREQCC-using code can compile cleanly.

#pragma COPYRIGHT

Syntax: #pragma COPYRIGHT <message>

Changes the string to be embedded at the end of a compiled progs. <message> is the message to embed.

#pragma TARGET

Syntax: #pragma TARGET <target>

Switches compiled progs to a specific target type.

<target> can be the following:

ID, STANDARD: standard Quake progs
KK7: kkqwsv progs
H2, HEXEN2: Hexen 2 progs
FTE: FTE progs
DEBUG, FTEDEBUG: FTE progs with debug information

It is not recommended to switch target types during compilation.

#pragma PROGS_SRC