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cc65/test/ref/otccex.c
Greg King a0db846a97 Allowed old-style (K and R) function declarations to be fastcall.
That lets them match old-style definitions.  It avoids "Type conflict" error messages.  It allows shorter function calls.

Fixed the types of some variables in "test/ref/otccex.c".  It avoids crashes on 64-bit Windows (32-bit Windows with 64-bit pointers).
2019-07-22 09:26:23 -04:00

156 lines
3.8 KiB
C

/*
!!DESCRIPTION!! OTCC Example (simple K&R Style)
!!ORIGIN!! OTCC
!!LICENCE!! GPL (?), read COPYING.GPL
*/
#include "common.h"
/*
* Sample OTCC C example. You can uncomment the first line and install
* otcc in /usr/local/bin to make otcc scripts !
*/
/* Any preprocessor directive except #define are ignored. We put this
include so that a standard C compiler can compile this code too. */
#include <stdio.h>
/* defines are handled, but macro arguments cannot be given. No
recursive defines are tolerated */
#define DEFAULT_BASE 10
#ifdef NO_IMPLICIT_FUNC_PROTOTYPES
void help(char *name);
#endif
/*
* Only old-style K&R prototypes are parsed. Only int arguments are
* allowed (implicit types).
*
* By benchmarking the execution time of this function (for example
* for fib(35)), you'll notice that OTCC is quite fast because it
* generates native i386 machine code.
*/
int fib(n)
int n;
{
printf("[fib(%d)]", n);
if (n <= 2)
return 1;
else
return fib(n-1) + fib(n-2);
}
/* Identifiers are parsed the same way as C: begins with letter or
'_', and then letters, '_', or digits. */
long fact(n)
int n;
{
/* local variables can be declared. Only 'int' type is supported */
int i;
long r;
r = 1;
/* 'while' and 'for' loops are supported */
for(i=2;i<=n;i++)
r = r * i;
return r;
}
/* Well, we could use printf, but it would be too easy */
void print_num(n, b)
long n; int b;
{
char *tab, *p, c;
/* Numbers can be entered in decimal, hexadecimal ('0x' prefix), and
octal ('0' prefix). */
/* More complex programs use malloc(). */
tab = malloc(0x100);
p = tab;
while (1) {
c = n % b;
/* Character constants can be used */
if (c >= 10)
c = c + 'a' - 10;
else
c = c + '0';
*p = c;
p++;
n = n / b;
/* 'break' is supported */
if (n == 0)
break;
}
while (p != tab) {
p--;
printf("%c", *p);
}
free(tab);
}
/* 'main' takes standard 'argc' and 'argv' parameters */
int mymain(argc, argv)
int argc; char **argv;
{
/* No local name space is supported, but local variables ARE
supported. As long as you do not use a globally defined
variable name as a local variable (which is a bad habit), you
won't have any problems. */
size_t s, f;
int n, base;
/* && and || operator have the same semantics as C (left to right
evaluation and early exit) */
if (argc != 2 && argc != 3) {
/* '*' operator is supported with explicit casting to 'int *',
'char *', or 'int (*)()' (function pointer). Of course, 'int'
are supposed to be used as pointers, too. */
s = *(size_t *)argv;
help((char *)s);
return 1;
}
/* Any libc function can be used because OTCC uses dynamic linking */
n = atoi(argv[1]);
base = DEFAULT_BASE;
if (argc >= 3) {
base = atoi(argv[2]);
if (base < 2 || base > 36) {
/* external variables can be used too (here: 'stderr') */
fprintf(stdout, "Invalid base\n");
return 1;
}
}
printf("fib(%d) =\n", n);
print_num(fib(n), base);
printf("\n");
printf("fact(%d) = ", n);
if (n > 12) {
printf("Overflow");
} else {
/* why not using a function pointer ? */
f = (size_t)&fact;
print_num((*(long (*)())f)(n), base);
}
printf("\n");
return 0;
}
/* functions can be used before being defined */
void help(char *name)
{
printf("usage: %s n [base]\n", name);
printf("Compute fib(n) and fact(n) and output the result in base 'base'\n");
}
int main(void)
{
char *argv[3];
argv[0]="otccex";
argv[1]="10"; /* n */
argv[2]="8"; /* base */
return mymain(3, argv);
}