8.4.2 Constructs

The following C declarations and statements are recognized:

defines

Defines are changed into Pascal constants if they are simple defines. Macros are changed - wherever possible - to functions; however the arguments are all integers, so these must be changed manually. Simple expressions in define staments are recognized, as are most arithmetic operators: addition, substraction, multiplication, division, logical operators, comparison operators, shift operators. The C construct ( A ? B : C) is also recognized and translated to a Pascal construct with an IF statement. (This is buggy, however).

preprocessor statements

The conditional preprocessing commands are recognized and translated into equivalent Pascal compiler directives. The special

#ifdef __cplusplus

is also recognized and removed.

typedef

A typedef statement is changed into a Pascal type statement. The following basic types are recognized:

• char changed to char.
• float changed to real (=double in Free Pascal).
• int changed to longint.
• long changed to longint.
• long int changed to longint.
• short changed to integer.
• unsigned changed to cardinal.
• unsigned char changed to byte.
• unsigned int changed to cardinal.
• unsigned long int changed to cardinal.
• unsigned short changed to word.
• void ignored.

These types are also changed if they appear in the arguments of a function or procedure.

functions and procedures

Functions and procedures are translated as well. Pointer types may be changed to call by reference arguments (using the var argument) by using the -p command line argument. Functions that have a variable number of arguments are changed to a function with a cvar modifier. (This used to be the array of const argument.)

specifiers

The extern specifier is recognized; however it is ignored. The packed specifier is also recognised and changed with the PACKRECORDS directive. The const specifier is also recognized, but is ignored.

modifiers

If the -w option is specified, then the following modifiers are recognized:

STDCALL  
CDECL  
CALLBACK  
PASCAL  
WINAPI  
APIENTRY  
WINGDIAPI

as defined in the win32 headers. If additionally the -x option is specified then the

SYS_TRAP

specifier is also recognized.

enums

Enum constructs are changed into enumeration types. Bear in mind that, in C, enumeration types can have values assigned to them. Free Pascal also allows this to a certain degree. If you know that values are assigned to enums, it is best to use the -e option to change the enumerations to a series of integer constants.

unions

Unions are changed to variant records.

structs

Structs are changed to Pascal records, with C packing.