rename common to src

+ I keep starting to type src and wondering why autocomplete won't work,
  I guess src is just uncounciously a better name

1 files changed, 463 insertions, 0 deletions

diff --git a/src/string.c b/src/string.c
new file mode 100644
index 0000000..8c88e65
--- /dev/null
+++ b/src/string.c
@@ -0,0 +1,463 @@
+/* SPDX-License-Identifier: copyleft-next-0.3.1 */
+/* Copyright 2021 - 2022, Kim Kuparinen < kimi.h.kuparinen@gmail.com > */
+
+/**
+ * @file string.c
+ * Implementations of some string.h stdlib functions.
+ */
+
+#include <kmi/string.h>
+#include <kmi/types.h>
+#include <kmi/attrs.h>
+
+/* we need to undef the macros in string.h, otherwise the names get mangled */
+#undef strcpy
+__weak char *strcpy(char * restrict dst, const char * restrict src)
+{
+	const char *s1 = src;
+	char *s2 = dst;
+
+	while (*s1)
+		*(s2++) = *(s1++);
+
+	return dst;
+}
+
+#undef strncpy
+__weak char *strncpy(char * restrict dst, const char * restrict src, size_t num)
+{
+	const char *s1 = src;
+	char *s2 = dst;
+
+	/* copy s1 into s2 */
+	while (num-- && *s1)
+		*(s2++) = *(s1++);
+
+	/* the previous loop always overshoots by one */
+	num++;
+
+	/* pad with zeroes if num is not yet zero */
+	while (num--)
+		*(s2++) = 0;
+
+	return dst;
+}
+
+#undef strcat
+__weak char *strcat(char * restrict dst, const char * restrict src)
+{
+	const char *s1 = src;
+	size_t l1 = strlen(s1);
+	char *s2 = dst + l1;
+
+	while (*s1)
+		*(s2++) = *(s1++);
+
+	/* append null character */
+	*s2 = 0;
+
+	return dst;
+}
+
+#undef strncat
+__weak char *strncat(char * restrict dst, const char * restrict src, size_t num)
+{
+	const char *s1 = src;
+	size_t l1 = strlen(s1);
+	char *s2 = dst + l1;
+
+	while (num-- && *s1)
+		*(s2++) = *(s1++);
+
+	/* append null character */
+	*s2 = 0;
+
+	return dst;
+}
+
+#undef strcmp
+__weak int strcmp(const char *str1, const char *str2)
+{
+	const char *s1 = (const char *)str1;
+	const char *s2 = (const char *)str2;
+
+	while ((*(s1++) == *(s2++)) && *s1 && *s2)
+		;
+
+	return (int)(s1[-1] - s2[-1]);
+}
+
+#undef strncmp
+__weak int strncmp(const char *str1, const char *str2, size_t num)
+{
+	const char *s1 = (const char *)str1;
+	const char *s2 = (const char *)str2;
+
+	while ((*(s1++) == *(s2++)) && *s1 && *s2 && --num)
+		;
+
+	return (int)(s1[-1] - s2[-1]);
+}
+
+#undef strchr
+__weak char *strchr(const char *str, int chr)
+{
+	const char *s1 = str;
+	ssize_t num = strlen(s1);
+
+	while (num-- && *(s1++) != chr)
+		;
+
+	if (num < 0)
+		return 0;
+
+	return (char *)(s1 - 1);
+}
+
+#undef strtok
+__weak char *strtok(char * restrict str, const char * restrict delims)
+{
+	static char *cont = 0;
+	const char *s1 = str;
+
+	if (!s1)
+		s1 = cont;
+
+	if (!s1)
+		return 0;
+
+	s1 = strpbrk(s1, delims);
+
+	if (!s1)
+		cont = 0;
+	else
+		cont = (char *)s1 + 1;
+
+	return (char *)s1;
+}
+
+/* should probably test out these functions somehwere, blergh */
+#undef strstr
+__weak char *strstr(const char *str1, const char *str2)
+{
+	/* boyer-moore-horspool */
+	char table[256] = { 0 };
+	size_t sl = strlen(str1);
+	size_t pl = strlen(str2);
+
+	const unsigned char *s1 = (const unsigned char *)str1;
+	const unsigned char *haystack = (const unsigned char *)s1;
+	const unsigned char *needle = (const unsigned char *)str2;
+
+	for (size_t i = 0; i < 256; ++i)
+		table[i] = pl;
+
+	/* generate deltas */
+	for (size_t i = 0; i < pl - 1; ++i)
+		table[needle[i]] = pl - i - 1;
+
+	size_t skip = 0;
+	while (sl - skip >= pl) {
+		s1 = &haystack[skip];
+
+		if (!memcmp(s1, needle, pl))
+			return (char *)s1;
+
+		skip += table[haystack[skip + pl - 1]];
+	}
+
+	return 0;
+}
+
+#undef strrchr
+__weak char *strrchr(const char *str, int chr)
+{
+	ssize_t num = strlen(str);
+	const char *s1 = (str + num) - 1;
+
+	while (num-- && *(s1--) != chr)
+		;
+
+	if (num < 0)
+		return 0;
+
+	return (char *)(s1 + 1);
+}
+
+#undef strpbrk
+__weak char *strpbrk(const char *str1, const char *str2)
+{
+	size_t i = strcspn(str1, str2);
+
+	if (!i)
+		return 0;
+
+	return (char *)(str1 + i);
+}
+
+#undef strcspn
+__weak size_t strcspn(const char *str1, const char *str2)
+{
+	char table[256] = { 0 };
+	const unsigned char *s1 = (const unsigned char *)str1;
+	const unsigned char *s2 = (const unsigned char *)s1;
+	const unsigned char *t1 = (const unsigned char *)str2;
+
+	/* populate table */
+	while (*(t1++))
+		table[*t1] = 1;
+
+	for (;;) {
+		if (table[*(s2++)])
+			break;
+	}
+
+	/* the for loop overshoots by one */
+	return (size_t)(s2 - s1) - 1;
+}
+
+#undef strspn
+__weak size_t strspn(const char *str1, const char *str2)
+{
+	char table[256] = { 0 };
+	const unsigned char *s1 = (const unsigned char *)str1;
+	const unsigned char *s2 = (const unsigned char *)s1;
+	const unsigned char *t1 = (const unsigned char *)str2;
+
+	/* populate table */
+	while (*(t1++))
+		table[*t1] = 1;
+
+	for (;;) {
+		if (!table[*(s2++)])
+			break;
+	}
+
+	/* the for loop overshoots by one */
+	return (size_t)(s2 - s1) - 1;
+}
+
+#undef strlen
+__weak size_t strlen(const char *str)
+{
+	const char *s1 = str;
+	while (*(s1++))
+		;
+
+	/* the loop overshoots by one */
+	return (size_t)(s1 - str) - 1;
+}
+
+/* not a macro */
+__weak size_t strnlen(const char *str, size_t num)
+{
+	const char *s1 = str;
+	while (num-- && *(s1++))
+		;
+
+	return (size_t)(s1 - str) - 1;
+}
+
+#undef memset
+__weak void *memset(void *ptr, int value, size_t num)
+{
+	char *p = ptr;
+	char c = value;
+
+	while (num--)
+		*(p++) = c;
+
+	return ptr;
+}
+
+#undef memchr
+__weak void *memchr(const void *ptr, int val, size_t num)
+{
+	const char *p1 = (char *)ptr;
+	ssize_t n = num;
+	char c = (char)val;
+
+	while (n-- && *(p1++) != c)
+		;
+
+	if (n < 0)
+		return 0;
+
+	return (void *)(p1 - 1);
+}
+
+#undef memcpy
+__weak void *memcpy(void * restrict dst, const void * restrict src, size_t num)
+{
+	const char *m1 = (const char *)src;
+	char *m2 = (char *)dst;
+
+	while (num--)
+		*(m2++) = *(m1++);
+
+	return dst;
+}
+
+#undef memmove
+__weak void *memmove(void *dst, const void *src, size_t num)
+{
+	const char *m1 = (const char *)src;
+	char *m2 = (char *)dst;
+
+	m1 += num;
+	m2 += num;
+
+	/* doesn't really take into account aliasing yet */
+	while (num--)
+		*(--m2) = *(--m1);
+
+	return dst;
+}
+
+#undef memcmp
+__weak int memcmp(const void *ptr1, const void *ptr2, size_t num)
+{
+	const char *p1 = (const char *)ptr1;
+	const char *p2 = (const char *)ptr2;
+
+	while ((*(p1++) == *(p2++)) && --num)
+		;
+
+	return (int)(p1[-1] - p2[-1]);
+}
+
+/**
+ * Convert ASCII hex character to integer.
+ * Allows both upper- and lowercase letters.
+ *
+ * @param c Character to convert.
+ * @return Corresponding integer value. That is, '1' => 1, '2' => 2, etc.
+ * \c -1 if conversion failed.
+ */
+static int __hexval(char c)
+{
+	if (c >= '0' && c <= '9')
+		return c - '0';
+
+	if (c >= 'a' && c <= 'f')
+		return 10 + c - 'a';
+
+	if (c >= 'A' && c <= 'F')
+		return 10 + c - 'A';
+
+	return -1;
+}
+
+/**
+ * Convert string assumed to represent hex
+ * value to corresponding pointer.
+ *
+ * @param s String to convert to value.
+ * @return Corresponding pointer value.
+ */
+static uintptr_t __hexuintptr(const char *s)
+{
+	uintptr_t res = 0;
+	int val = 0;
+	while ((val = __hexval(*(s++))) != -1) {
+		res *= 16;
+		res += val;
+	}
+
+	return res;
+}
+
+/**
+ * Convert ASCII decimal character to integer.
+ *
+ * @param c Character to convert.
+ * @return Corresponding integer value. That is, '1' => 1, '2' => 2, etc.
+ * \c -1 if conversion failed.
+ */
+static int __decval(char c)
+{
+	if (c >= '0' && c <= '9')
+		return c - '0';
+
+	return -1;
+}
+
+/**
+ * Convert string assumed to represent decimal
+ * value to corresponding pointer.
+ *
+ * @param s String to convert to value.
+ * @return Corresponding pointer value.
+ */
+static uintptr_t __decuintptr(const char *s)
+{
+	uintptr_t res = 0;
+	int val = 0;
+	while ((val = __decval(*(s++))) != -1) {
+		res *= 10;
+		res += val;
+	}
+
+	return res;
+}
+
+/**
+ * Convert ASCII octal character to integer.
+ *
+ * @param c Character to convert.
+ * @return Corresponding integer value. That is, '1' => 1, '2' => 2, etc.
+ * \c -1 if conversion failed.
+ */
+static int __octval(char c)
+{
+	if (c >= '0' && c <= '7')
+		return c - '0';
+
+	return -1;
+}
+
+/**
+ * Convert string assumed to represent octal
+ * value to corresponding pointer.
+ *
+ * @param s String to convert to value.
+ * @return Corresponding pointer value.
+ */
+static uintptr_t __octuintptr(const char *s)
+{
+	uintptr_t res = 0;
+	int val = 0;
+	while ((val = __octval(*(s++))) != -1) {
+		res *= 8;
+		res += val;
+	}
+
+	return res;
+}
+
+uintptr_t strtouintptr(const char *s)
+{
+	if (!s)
+		return 0;
+
+	if (s[0] == 0)
+		return 0;
+
+	if (s[0] == '0') {
+		if (s[1] == 0)
+			return 0;
+
+		if (s[1] == 'x' || s[1] == 'X')
+			return __hexuintptr(s + 2);
+
+		return __octuintptr(s + 1);
+	}
+
+	if (s[0] == '-')
+		return -__decuintptr(s + 1);
+
+	if (s[0] == '+')
+		return __decuintptr(s + 1);
+
+	return __decuintptr(s);
+}