This is output from `defines' version 4.1.1, from your buddies at Newtware!
Sun Apr 15 16:03:36 GMT+0800 2012
386BSD 386bsd 1.0 #Jolix-1.0 i386
cc = [cc]

strings: 2: No such file or directory
__386BSD__	= 1 
__BASE_FILE__	= "/tmp/def256.c"
__DATE__	= "Apr 15 2012"
__FILE__	= "/tmp/def256.c"
__GNUC__	= 2 
__INCLUDE_LEVEL__	= 0
__LINE__	= 5126
__PTRDIFF_TYPE__	= int
__SIZE_TYPE__	= unsigned int
__STDC__	= 1
__TIME__	= "16:03:37"
__VERSION__	= "2.4.5"
__WCHAR_TYPE__	= short unsigned int
i386	= 1 
unix	= 1 

Checking other possibilities; should already be listed above:
__DATE__	= "Apr 15 2012"
__FILE__	= "/tmp/def256.c"
__GNUC__	= 2
__LINE__	= 25
__STDC__	= 1
__TIME__	= "16:03:37"

Sizes of basic variable types:
  sizeof(char)           = 8 bits
  sizeof(short)          = 16 bits
  sizeof(int)            = 32 bits
  sizeof(long)           = 32 bits
  sizeof(float)          = 32 bits
  sizeof(double)         = 64 bits
  sizeof(long double)    = 64 bits
  sizeof(char *)         = 32 bits
  sizeof(char (*)(char)) = 32 bits