X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?p=bootcensus;a=blobdiff_plain;f=src%2Flibc%2Fstdlib.c;fp=src%2Flibc%2Fstdlib.c;h=6b130edd3fb5c9bfe20c7834552d47c886d99b26;hp=b3acce24b1a39f4187db512b82ddaa7007ec2868;hb=81c11bdd80190ec319a82b0402173cfb65fcbf72;hpb=7dcd5071e600f8cf48174d1fddb3dba57ec9476d

diff --git a/src/libc/stdlib.c b/src/libc/stdlib.c
index b3acce2..6b130ed 100644
--- a/src/libc/stdlib.c
+++ b/src/libc/stdlib.c
@@ -1,6 +1,6 @@
 /*
 pcboot - bootable PC demo/game kernel
-Copyright (C) 2018  John Tsiombikas <nuclear@member.fsf.org>
+Copyright (C) 2018-2019  John Tsiombikas <nuclear@member.fsf.org>
 
 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
@@ -16,7 +16,11 @@ You should have received a copy of the GNU General Public License
 along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */
 #include <stdlib.h>
+#include <string.h>
 #include <ctype.h>
+#include <limits.h>
+#include <assert.h>
+#include <alloca.h>
 
 int atoi(const char *str)
 {
@@ -32,6 +36,8 @@ long strtol(const char *str, char **endp, int base)
 {
 	long acc = 0;
 	int sign = 1;
+	int valid = 0;
+	const char *start = str;
 
 	while(isspace(*str)) str++;
 
@@ -55,24 +61,27 @@ long strtol(const char *str, char **endp, int base)
 	}
 
 	while(*str) {
-		long val;
+		long val = LONG_MAX;
 		char c = tolower(*str);
 
 		if(isdigit(c)) {
 			val = *str - '0';
-		} else if(c >= 'a' || c <= 'f') {
+		} else if(c >= 'a' && c <= 'f') {
 			val = 10 + c - 'a';
+		} else {
+			break;
 		}
 		if(val >= base) {
 			break;
 		}
+		valid = 1;
 
 		acc = acc * base + val;
 		str++;
 	}
 
 	if(endp) {
-		*endp = (char*)str;
+		*endp = (char*)(valid ? str : start);
 	}
 
 	return sign > 0 ? acc : -acc;
@@ -134,3 +143,130 @@ void utoa(unsigned int val, char *buf, int base)
 	*buf = 0;
 }
 
+double atof(const char *str)
+{
+	return strtod(str, 0);
+}
+
+
+double strtod(const char *str, char **endp)
+{
+	char *ep;
+	const char *start = str;
+	int valid = 0;
+	long ival = 0, dval = 0;
+	int ddig = 0;
+	double res;
+
+	/* integer part */
+	ival = strtol(str, &ep, 10);
+	if(ep == str && *str != '.') {
+		if(endp) *endp = (char*)str;
+		return 0.0;
+	}
+	if(ep != str) valid = 1;
+	str = *ep == '.' ? ep + 1 : ep;
+	if(!isdigit(*str)) {
+		goto done;
+	}
+	valid = 1;
+
+	dval = strtol(str, &ep, 10);
+	assert(dval >= 0);
+	ddig = ep - str;
+	str = ep;
+
+done:
+	if(*endp) {
+		*endp = (char*)(valid ? str : start);
+	}
+
+	res = (double)ival;
+	if(ddig) {
+		double d = (double)dval;
+		while(ddig-- > 0) {
+			d /= 10.0;
+		}
+		res += d;
+	}
+	return res;
+}
+
+int atexit(void (*func)(void))
+{
+	/* there's no concept of exiting at the moment, so this does nothing */
+	return 0;
+}
+
+void abort(void)
+{
+	panic("Aborted\n");
+}
+
+#define QSORT_THRESHOLD	4
+#define ITEM(idx)	((char*)arr + (idx) * itemsz)
+
+#define SWAP(p, q) \
+	do { \
+		int nn = itemsz; \
+		char *pp = (p); \
+		char *qq = (q); \
+		do { \
+			char tmp = *pp; \
+			*pp++ = *qq; \
+			*qq++ = tmp; \
+		} while(--nn > 0); \
+	} while(0)
+
+static void ins_sort(void *arr, size_t count, size_t itemsz, int (*cmp)(const void*, const void*))
+{
+	int i;
+	char *it, *a, *b;
+
+	if(count <= 1) return;
+
+	it = (char*)arr + itemsz;
+	for(i=1; i<count; i++) {
+		a = it;
+		it += itemsz;
+		while(a > (char*)arr && cmp(a, (b = a - itemsz)) < 0) {
+			SWAP(a, b);
+			a -= itemsz;
+		}
+	}
+}
+
+void qsort(void *arr, size_t count, size_t itemsz, int (*cmp)(const void*, const void*))
+{
+	char *ma, *mb, *mc, *left, *right;
+	size_t sepidx, nleft, nright;
+
+	if(count <= 1) return;
+
+	if(count < QSORT_THRESHOLD) {
+		ins_sort(arr, count, itemsz, cmp);
+		return;
+	}
+
+	ma = arr;
+	mb = ITEM(count / 2);
+	mc = ITEM(count - 1);
+	if(cmp(ma, mb) < 0) SWAP(ma, mb);
+	if(cmp(mc, ma) < 0) SWAP(mc, ma);
+
+	left = ma + itemsz;
+	right = mc - itemsz;
+	for(;;) {
+		while(cmp(left, ma) < 0) left += itemsz;
+		while(cmp(ma, right) < 0) right -= itemsz;
+		if(left >= right) break;
+		SWAP(left, right);
+	}
+	SWAP(ma, right);
+	sepidx = (right - (char*)arr) / itemsz;
+	nleft = sepidx;
+	nright = count - nleft - 1;
+
+	qsort(ma, nleft, itemsz, cmp);
+	qsort(right + itemsz, nright, itemsz, cmp);
+}