Commit FS#9174: Lua scripting language by Dan Everton

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@21020 a1c6a512-1295-4272-9138-f99709370657

apps/plugins/lua/strtoul.c

@@ -0,0 +1,53 @@
+#include "rocklibc.h"
+
+unsigned long int strtoul(const char *ptr, char **endptr, int base)
+{
+  int neg = 0, overflow = 0;
+  unsigned long int v=0;
+  const char* orig;
+  const char* nptr=ptr;
+
+  while(isspace(*nptr)) ++nptr;
+
+  if (*nptr == '-') { neg=1; nptr++; }
+  else if (*nptr == '+') ++nptr;
+  orig=nptr;
+  if (base==16 && nptr[0]=='0') goto skip0x;
+  if (base) {
+    register unsigned int b=base-2;
+    if (__unlikely(b>34)) { errno=EINVAL; return 0; }
+  } else {
+    if (*nptr=='0') {
+      base=8;
+skip0x:
+      if ((nptr[1]=='x'||nptr[1]=='X') && isxdigit(nptr[2])) {
+	nptr+=2;
+	base=16;
+      }
+    } else
+      base=10;
+  }
+  while(__likely(*nptr)) {
+    register unsigned char c=*nptr;
+    c=(c>='a'?c-'a'+10:c>='A'?c-'A'+10:c<='9'?c-'0':0xff);
+    if (__unlikely(c>=base)) break;	/* out of base */
+    {
+      register unsigned long x=(v&0xff)*base+c;
+      register unsigned long w=(v>>8)*base+(x>>8);
+      if (w>(ULONG_MAX>>8)) overflow=1;
+      v=(w<<8)+(x&0xff);
+    }
+    ++nptr;
+  }
+  if (__unlikely(nptr==orig)) {		/* no conversion done */
+    nptr=ptr;
+    errno=EINVAL;
+    v=0;
+  }
+  if (endptr) *endptr=(char *)nptr;
+  if (overflow) {
+    errno=ERANGE;
+    return ULONG_MAX;
+  }
+  return (neg?-v:v);
+}