Import sources from 2011-03-30 iso image

1 files changed, 91 insertions, 0 deletions

diff --git a/sys/src/ape/lib/ap/gen/strtod.c b/sys/src/ape/lib/ap/gen/strtod.c
new file mode 100755
index 000000000..ca4939100
--- /dev/null
+++ b/sys/src/ape/lib/ap/gen/strtod.c
@@ -0,0 +1,91 @@
+#include <math.h>
+#include <errno.h>
+
+/*
+ * bug: should detect overflow, set errno = ERANGE, and return +/- HUGE_VAL
+ */
+double
+strtod(const char *cp, char **endptr)
+{
+	double num, dem;
+	extern double pow10(int);
+	int neg, eneg, dig, predig, exp, c;
+	const char *p;
+
+	p = cp;
+	num = 0;
+	neg = 0;
+	dig = 0;
+	predig = 0;
+	exp = 0;
+	eneg = 0;
+
+	c = *p++;
+	while(c == ' ' || c == '\t' || c == '\n' || c == '\f' || c == '\v' || c == '\r')
+		c = *p++;
+	if(c == '-' || c == '+'){
+		if(c == '-')
+			neg = 1;
+		c = *p++;
+	}
+	while(c >= '0' && c <= '9'){
+		num = num*10 + c-'0';
+		predig++;
+		c = *p++;
+	}
+	if(c == '.')
+		c = *p++;
+	while(c >= '0' && c <= '9'){
+		num = num*10 + c-'0';
+		dig++;
+		c = *p++;
+	}
+	if(dig+predig == 0){
+		if(endptr)
+			*endptr = (char *)cp;
+		return 0.0;
+	}
+	if(c == 'e' || c == 'E'){
+		c = *p++;
+		if(c == '-' || c == '+'){
+			if(c == '-'){
+				dig = -dig;
+				eneg = 1;
+			}
+			c = *p++;
+		}
+		while(c >= '0' && c <= '9'){
+			exp = exp*10 + c-'0';
+			c = *p++;
+		}
+	}
+	exp -= dig;
+	if(exp < 0){
+		exp = -exp;
+		eneg = !eneg;
+	}
+	dem = pow10(exp);
+	if(dem==HUGE_VAL)
+		num = eneg? 0.0 : HUGE_VAL;
+	else if(dem==0)
+		num = eneg? HUGE_VAL : 0.0;
+	else if(eneg)
+		num /= dem;
+	else
+		num *= dem;
+	if(neg)
+		num = -num;
+	if(endptr){
+		*endptr = (char *)--p;
+		/*
+		 * Fix cases like 2.3e+
+		 */
+		while(p > cp){
+			c = *--p;
+			if(c!='-' && c!='+' && c!='e' && c!='E')
+				break;
+			(*endptr)--;
+		}
+	}
+	return num;
+}