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/* Copyright (c) 2002-2006 Lucent Technologies; see LICENSE */
#include <stdarg.h>
#include <string.h>
/*
* As of 2020, older systems like RHEL 6 and AIX still do not have C11 atomics.
* On those systems, make the code use volatile int accesses and hope for the best.
* (Most uses of fmtinstall are not actually racing with calls to print that lookup
* formats. The code used volatile here for years without too many problems,
* even though that's technically racy. A mutex is not OK, because we want to
* be able to call print from signal handlers.)
*
* RHEL is using an old GCC (atomics were added in GCC 4.9).
* AIX is using its own IBM compiler (XL C).
*/
#if __IBMC__ || !__clang__ && __GNUC__ && (__GNUC__ < 4 || (__GNUC__==4 && __GNUC_MINOR__<9))
#warning not using C11 stdatomic on legacy system
#define _Atomic volatile
#define atomic_load(x) (*(x))
#define atomic_store(x, y) (*(x)=(y))
#define ATOMIC_VAR_INIT(x) (x)
#else
#include <stdatomic.h>
#endif
#include "plan9.h"
#include "fmt.h"
#include "fmtdef.h"
enum
{
Maxfmt = 128
};
typedef struct Convfmt Convfmt;
struct Convfmt
{
int c;
Fmts fmt;
};
static struct
{
/*
* lock updates to fmt by calling __fmtlock, __fmtunlock.
* reads can start at nfmt and work backward without
* further locking. later fmtinstalls take priority over earlier
* ones because of the backwards loop.
* once installed, a format is never overwritten.
*/
_Atomic int nfmt;
Convfmt fmt[Maxfmt];
} fmtalloc = {
#ifdef PLAN9PORT
ATOMIC_VAR_INIT(27),
#else
ATOMIC_VAR_INIT(30),
#endif
{
{' ', __flagfmt},
{'#', __flagfmt},
{'%', __percentfmt},
{'\'', __flagfmt},
{'+', __flagfmt},
{',', __flagfmt},
{'-', __flagfmt},
{'C', __runefmt}, /* Plan 9 addition */
{'E', __efgfmt},
#ifndef PLAN9PORT
{'F', __efgfmt}, /* ANSI only */
#endif
{'G', __efgfmt},
#ifndef PLAN9PORT
{'L', __flagfmt}, /* ANSI only */
#endif
{'S', __runesfmt}, /* Plan 9 addition */
{'X', __ifmt},
{'b', __ifmt}, /* Plan 9 addition */
{'c', __charfmt},
{'d', __ifmt},
{'e', __efgfmt},
{'f', __efgfmt},
{'g', __efgfmt},
{'h', __flagfmt},
#ifndef PLAN9PORT
{'i', __ifmt}, /* ANSI only */
#endif
{'l', __flagfmt},
{'n', __countfmt},
{'o', __ifmt},
{'p', __ifmt},
{'r', __errfmt},
{'s', __strfmt},
#ifdef PLAN9PORT
{'u', __flagfmt},
#else
{'u', __ifmt},
#endif
{'x', __ifmt},
}
};
int (*fmtdoquote)(int);
/*
* __fmtlock() must be set
*/
static int
__fmtinstall(int c, Fmts f)
{
Convfmt *p;
int i;
if(c<=0 || c>=65536)
return -1;
if(!f)
f = __badfmt;
i = atomic_load(&fmtalloc.nfmt);
if(i == Maxfmt)
return -1;
p = &fmtalloc.fmt[i];
p->c = c;
p->fmt = f;
atomic_store(&fmtalloc.nfmt, i+1);
return 0;
}
int
fmtinstall(int c, int (*f)(Fmt*))
{
int ret;
__fmtlock();
ret = __fmtinstall(c, f);
__fmtunlock();
return ret;
}
static Fmts
fmtfmt(int c)
{
Convfmt *p, *ep;
ep = &fmtalloc.fmt[atomic_load(&fmtalloc.nfmt)];
for(p=ep; p-- > fmtalloc.fmt; )
if(p->c == c)
return p->fmt;
return __badfmt;
}
void*
__fmtdispatch(Fmt *f, void *fmt, int isrunes)
{
Rune rune, r;
int i, n;
f->flags = 0;
f->width = f->prec = 0;
for(;;){
if(isrunes){
r = *(Rune*)fmt;
fmt = (Rune*)fmt + 1;
}else{
fmt = (char*)fmt + chartorune(&rune, (char*)fmt);
r = rune;
}
f->r = r;
switch(r){
case '\0':
return nil;
case '.':
f->flags |= FmtWidth|FmtPrec;
continue;
case '0':
if(!(f->flags & FmtWidth)){
f->flags |= FmtZero;
continue;
}
/* fall through */
case '1': case '2': case '3': case '4':
case '5': case '6': case '7': case '8': case '9':
i = 0;
while(r >= '0' && r <= '9'){
i = i * 10 + r - '0';
if(isrunes){
r = *(Rune*)fmt;
fmt = (Rune*)fmt + 1;
}else{
r = *(char*)fmt;
fmt = (char*)fmt + 1;
}
}
if(isrunes)
fmt = (Rune*)fmt - 1;
else
fmt = (char*)fmt - 1;
numflag:
if(f->flags & FmtWidth){
f->flags |= FmtPrec;
f->prec = i;
}else{
f->flags |= FmtWidth;
f->width = i;
}
continue;
case '*':
i = va_arg(f->args, int);
if(i < 0){
/*
* negative precision =>
* ignore the precision.
*/
if(f->flags & FmtPrec){
f->flags &= ~FmtPrec;
f->prec = 0;
continue;
}
i = -i;
f->flags |= FmtLeft;
}
goto numflag;
}
n = (*fmtfmt(r))(f);
if(n < 0)
return nil;
if(n == 0)
return fmt;
}
}
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