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remove can't happen code and instead force a compile time error

master
Felix von Leitner 8 years ago
parent
commit
20d899eb7e
  1. 20
      scan/scan_uint.c
  2. 21
      scan/scan_ushort.c

20
scan/scan_uint.c

@ -21,20 +21,10 @@ size_t scan_uint(const char* src,unsigned int* dest) {
if (cur>src) *dest=l;
return (size_t)(cur-src);
} else {
register const char *tmp=src;
register unsigned int l=0;
register unsigned char c;
while ((c=(unsigned char)(*tmp-'0'))<10) {
unsigned int n;
/* division is very slow on most architectures */
n=l<<3; if ((n>>3)!=l) break;
if (n+(l<<1) < n) break;
n+=l<<1;
if (n+c < n) break;
l=n+c;
++tmp;
}
if (tmp-src) *dest=l;
return (size_t)(tmp-src);
/* the C standard says that sizeof(short) <= sizeof(unsigned int) <=
* sizeof(unsigned long); this can never happen. Provoke a compile
* error if it does */
char compileerror[sizeof(unsigned long)-sizeof(unsigned int)];
(void)compileerror;
}
}

21
scan/scan_ushort.c

@ -11,6 +11,7 @@ size_t scan_ushort(const char* src,unsigned short* dest) {
* needed */
return scan_uint(src,(unsigned int*)dest);
} if (sizeof(unsigned short) < sizeof(unsigned long)) {
/* this is the regular case */
const char* cur;
unsigned short l;
for (cur=src,l=0; *cur>='0' && *cur<='9'; ++cur) {
@ -21,20 +22,10 @@ size_t scan_ushort(const char* src,unsigned short* dest) {
if (cur>src) *dest=l;
return (size_t)(cur-src);
} else {
register const char *tmp=src;
register unsigned short int l=0;
register unsigned char c;
while ((c=(unsigned char)(*tmp-'0'))<10) {
unsigned short int n;
/* division is very slow on most architectures */
n=(unsigned short)(l<<3); if ((n>>3)!=l) break;
if ((unsigned short)(n+(l<<1)) < n) break;
n=(unsigned short)(n+(l<<1));
if ((unsigned short)(n+c) < n) break;
l=(unsigned short)(n+c);
++tmp;
}
if (tmp-src) *dest=l;
return (size_t)(tmp-src);
/* the C standard says that sizeof(short) <= sizeof(unsigned int) <=
* sizeof(unsigned long); this can never happen. Provoke a compile
* error if it does */
char compileerror[sizeof(unsigned long)-sizeof(unsigned short)];
(void)compileerror;
}
}

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