Add build system scaffolding and libc headers

32 files changed, 629 insertions, 0 deletions

diff --git a/lib/libc/string/memccpy.c b/lib/libc/string/memccpy.c
new file mode 100644
index 00000000..29828182
--- /dev/null
+++ b/lib/libc/string/memccpy.c
@@ -0,0 +1,13 @@
+#include <stddef.h>
+
+void *memccpy(void *restrict s1, const void *restrict s2, int c, size_t n)
+{
+	const unsigned char *p2 = s2;
+	unsigned char *p1 = s1;
+	while (n--) {
+		if (*p2 == (unsigned char)c)
+			return p1 + 1;
+		*p1++ = *p2++;
+	}
+	return NULL;
+}
diff --git a/lib/libc/string/memchr.c b/lib/libc/string/memchr.c
new file mode 100644
index 00000000..38850aed
--- /dev/null
+++ b/lib/libc/string/memchr.c
@@ -0,0 +1,12 @@
+#include <stddef.h>
+
+void *memchr(const void *s, int c, size_t n)
+{
+	const unsigned char *p = s;
+	while (n--) {
+		if (*p == (unsigned char)c)
+			return (void *)p;
+		p++;
+	}
+	return NULL;
+}
diff --git a/lib/libc/string/memcmp.c b/lib/libc/string/memcmp.c
new file mode 100644
index 00000000..5efb282f
--- /dev/null
+++ b/lib/libc/string/memcmp.c
@@ -0,0 +1,14 @@
+#include <stddef.h>
+
+int memcmp(const void *s1, const void *s2, size_t n)
+{
+	const unsigned char *p1 = s1;
+	const unsigned char *p2 = s2;
+	while (n--) {
+		if (*p1 != *p2)
+			return *p1 - *p2;
+		p1++;
+		p2++;
+	}
+	return 0;
+}
diff --git a/lib/libc/string/memcpy.c b/lib/libc/string/memcpy.c
new file mode 100644
index 00000000..505cc622
--- /dev/null
+++ b/lib/libc/string/memcpy.c
@@ -0,0 +1,16 @@
+#include <string.h>
+#include <features.h>
+
+weak void *memcpy(void *restrict s1, const void *restrict s2, size_t n);
+
+void *memcpy(void *restrict s1, const void *restrict s2, size_t n)
+{
+	unsigned char *dest = (unsigned char *)s1;
+	const unsigned char *src = (const unsigned char *)s2;
+
+	while (n--) {
+		*dest++ = *src++;
+	}
+
+	return s1;
+}
diff --git a/lib/libc/string/memmem.c b/lib/libc/string/memmem.c
new file mode 100644
index 00000000..7a450cf7
--- /dev/null
+++ b/lib/libc/string/memmem.c
@@ -0,0 +1,15 @@
+#include <string.h>
+
+void *memmem(const void *haystack, size_t haystacklen, const void *needle,
+	     size_t needlelen)
+{
+	const unsigned char *p1 = haystack;
+	const unsigned char *p2 = needle;
+	while (haystacklen >= needlelen) {
+		if (!memcmp(p1, p2, needlelen))
+			return (void *)p1;
+		p1++;
+		haystacklen--;
+	}
+	return NULL;
+}
diff --git a/lib/libc/string/memmove.c b/lib/libc/string/memmove.c
new file mode 100644
index 00000000..88968185
--- /dev/null
+++ b/lib/libc/string/memmove.c
@@ -0,0 +1,21 @@
+#include <stddef.h>
+#include <stdint.h>
+
+void *memmove(void *dst, const void *src, size_t n)
+{
+	uint8_t *d = dst;
+	const uint8_t *s = src;
+
+	if (d == s || n == 0)
+		return dst;
+
+	if ((uintptr_t)d < (uintptr_t)s) {
+		for (size_t i = 0; i < n; i++)
+			d[i] = s[i];
+	} else {
+		for (size_t i = n; i != 0; i--)
+			d[i - 1] = s[i - 1];
+	}
+
+	return dst;
+}
diff --git a/lib/libc/string/memset.c b/lib/libc/string/memset.c
new file mode 100644
index 00000000..da969d16
--- /dev/null
+++ b/lib/libc/string/memset.c
@@ -0,0 +1,10 @@
+#include <string.h>
+
+void *memset(void *s, int c, size_t n)
+{
+	unsigned char *p = s;
+	while (n--) {
+		*p++ = (unsigned char)c;
+	}
+	return s;
+}
diff --git a/lib/libc/string/stpcpy.c b/lib/libc/string/stpcpy.c
new file mode 100644
index 00000000..04c3a17f
--- /dev/null
+++ b/lib/libc/string/stpcpy.c
@@ -0,0 +1,8 @@
+#include <string.h>
+
+char *stpcpy(char *restrict s1, const char *restrict s2)
+{
+	while ((*s1++ = *s2++))
+		;
+	return s1 - 1;
+}
diff --git a/lib/libc/string/stpncpy.c b/lib/libc/string/stpncpy.c
new file mode 100644
index 00000000..8f7ebd01
--- /dev/null
+++ b/lib/libc/string/stpncpy.c
@@ -0,0 +1,14 @@
+#include <stddef.h>
+
+char *strncpy(char *restrict s1, const char *restrict s2, size_t n)
+{
+	char *d = s1;
+
+	while (n-- && *s2)
+		*d++ = *s2++;
+
+	while (n--)
+		*d++ = '\0';
+
+	return s1;
+}
diff --git a/lib/libc/string/strcat.c b/lib/libc/string/strcat.c
new file mode 100644
index 00000000..6caf8c78
--- /dev/null
+++ b/lib/libc/string/strcat.c
@@ -0,0 +1,14 @@
+char *strcat(char *restrict s1, const char *restrict s2)
+{
+	char *d = s1;
+
+	while (*d)
+		d++;
+
+	while (*s2)
+		*d++ = *s2++;
+
+	*d = '\0';
+
+	return s1;
+}
diff --git a/lib/libc/string/strchr.c b/lib/libc/string/strchr.c
new file mode 100644
index 00000000..db632a2e
--- /dev/null
+++ b/lib/libc/string/strchr.c
@@ -0,0 +1,13 @@
+#include <string.h>
+
+char *strchr(const char *s, int c)
+{
+	while (*s) {
+		if (*s == (char)c)
+			return (char *)s;
+		s++;
+	}
+	if (c == 0)
+		return (char *)s;
+	return NULL;
+}
diff --git a/lib/libc/string/strcmp.c b/lib/libc/string/strcmp.c
new file mode 100644
index 00000000..836522f1
--- /dev/null
+++ b/lib/libc/string/strcmp.c
@@ -0,0 +1,23 @@
+#include <stddef.h>
+
+int strcmp(const char *s1, const char *s2)
+{
+	const unsigned char *p1 = (const unsigned char *)s1;
+	const unsigned char *p2 = (const unsigned char *)s2;
+
+	if (p1 == NULL && p2 == NULL)
+		return 0;
+
+	if (p1 == NULL)
+		return -1;
+
+	if (p2 == NULL)
+		return 1;
+
+	while (*p1 == *p2 && *p1 != '\0') {
+		p1++;
+		p2++;
+	}
+
+	return *p1 - *p2;
+}
diff --git a/lib/libc/string/strcoll.c b/lib/libc/string/strcoll.c
new file mode 100644
index 00000000..6b2e532a
--- /dev/null
+++ b/lib/libc/string/strcoll.c
@@ -0,0 +1,13 @@
+#include <libc.h>
+#include <string.h>
+#include <locale.h>
+
+int strcoll(const char *s1, const char *s2)
+{
+	return strcmp(s1, s2);
+}
+
+weak int strcoll_l(const char *s1, const char *s2, locale_t unused locale)
+{
+	return strcoll(s1, s2);
+}
diff --git a/lib/libc/string/strcpy.c b/lib/libc/string/strcpy.c
new file mode 100644
index 00000000..8e1dab69
--- /dev/null
+++ b/lib/libc/string/strcpy.c
@@ -0,0 +1,7 @@
+char *strcpy(char *restrict s1, const char *restrict s2)
+{
+	char *p = s1;
+	while ((*p++ = *s2++) != '\0')
+		;
+	return s1;
+}
diff --git a/lib/libc/string/strcspn.c b/lib/libc/string/strcspn.c
new file mode 100644
index 00000000..9f1f2bcd
--- /dev/null
+++ b/lib/libc/string/strcspn.c
@@ -0,0 +1,11 @@
+#include <string.h>
+
+size_t strcspn(const char *s1, const char *s2)
+{
+	size_t len = 0;
+	while (*s1 != '\0' && strchr(s2, *s1) == NULL) {
+		s1++;
+		len++;
+	}
+	return len;
+}
diff --git a/lib/libc/string/strdup.c b/lib/libc/string/strdup.c
new file mode 100644
index 00000000..1210bfdc
--- /dev/null
+++ b/lib/libc/string/strdup.c
@@ -0,0 +1,12 @@
+#include <stdlib.h>
+#include <string.h>
+
+char *strdup(const char *s)
+{
+	size_t len = strlen(s) + 1;
+	char *dup = malloc(len);
+	if (dup == NULL)
+		return NULL;
+	memcpy(dup, s, len);
+	return dup;
+}
diff --git a/lib/libc/string/strerror.c b/lib/libc/string/strerror.c
new file mode 100644
index 00000000..1d5903cb
--- /dev/null
+++ b/lib/libc/string/strerror.c
@@ -0,0 +1,125 @@
+#include <libc.h>
+#include <errno.h>
+#include <string.h>
+#include <locale.h>
+
+char *strerror(int errnum)
+{
+	char *table[] = {
+		[0] = "No error information",
+		[EILSEQ] = "Illegal byte sequence",
+		[EDOM] = "Domain error",
+		[ERANGE] = "Result not representable",
+		[ENOTTY] = "Not a tty",
+		[EACCES] = "Permission denied",
+		[EPERM] = "Operation not permitted",
+		[ENOENT] = "No such file or directory",
+		[ESRCH] = "No such process",
+		[EEXIST] = "File exists",
+		[EOVERFLOW] = "Value too large for data type",
+		[ENOSPC] = "No space left on device",
+		[ENOMEM] = "Out of memory",
+		[EBUSY] = "Resource busy",
+		[EINTR] = "Interrupted system call",
+		[EAGAIN] = "Resource temporarily unavailable",
+		[ESPIPE] = "Invalid seek",
+		[EXDEV] = "Cross-device link",
+		[EROFS] = "Read-only file system",
+		[ENOTEMPTY] = "Directory not empty",
+		[ECONNRESET] = "Connection reset by peer",
+		[ETIMEDOUT] = "Operation timed out",
+		[ECONNREFUSED] = "Connection refused",
+		[EHOSTDOWN] = "Host is down",
+		[EHOSTUNREACH] = "Host is unreachable",
+		[EADDRINUSE] = "Address in use",
+		[EPIPE] = "Broken pipe",
+		[EIO] = "I/O error",
+		[ENXIO] = "No such device or address",
+		[ENOTBLK] = "Block device required",
+		[ENODEV] = "No such device",
+		[ENOTDIR] = "Not a directory",
+		[EISDIR] = "Is a directory",
+		[ETXTBSY] = "Text file busy",
+		[ENOEXEC] = "Exec format error",
+		[EINVAL] = "Invalid argument",
+		[E2BIG] = "Argument list too long",
+		[ELOOP] = "Symbolic link loop",
+		[ENAMETOOLONG] = "Filename too long",
+		[ENFILE] = "Too many open files in system",
+		[EMFILE] = "No file descriptors available",
+		[EBADF] = "Bad file descriptor",
+		[ECHILD] = "No child process",
+		[EFAULT] = "Bad address",
+		[EFBIG] = "File too large",
+		[EMLINK] = "Too many links",
+		[ENOLCK] = "No locks available",
+		[EDEADLK] = "Resource deadlock would occur",
+		[ENOTRECOVERABLE] = "State not recoverable",
+		[EOWNERDEAD] = "Previous owner died",
+		[ECANCELED] = "Operation canceled",
+		[ENOSYS] = "Function not implemented",
+		[ENOMSG] = "No message of desired type",
+		[EIDRM] = "Identifier removed",
+		[ENOSTR] = "Device not a stream",
+		[ENODATA] = "No data available",
+		[ETIME] = "Device timeout",
+		[ENOSR] = "Out of streams resources",
+		[ENOLINK] = "Link has been severed",
+		[EPROTO] = "Protocol error",
+		[EBADMSG] = "Bad message",
+		[EBADFD] = "File descriptor in bad state",
+		[ENOTSOCK] = "Not a socket",
+		[EDESTADDRREQ] = "Destination address required",
+		[EMSGSIZE] = "Message too large",
+		[EPROTOTYPE] = "Protocol wrong type for socket",
+		[ENOPROTOOPT] = "Protocol not available",
+		[EPROTONOSUPPORT] = "Not supported",
+		[ESOCKTNOSUPPORT] = "Type not supported",
+		[ENOTSUP] = "Not supported",
+		[EPFNOSUPPORT] = "Protocol family not supported",
+		[EAFNOSUPPORT] = "Address family not supported by protocol",
+		[EADDRNOTAVAIL] = "Address not available",
+		[ENETDOWN] = "Network is down",
+		[ENETUNREACH] = "Network unreachable",
+		[ENETRESET] = "Connection reset by network",
+		[ECONNABORTED] = "Connection aborted",
+		[ENOBUFS] = "No buffer space available",
+		[EISCONN] = "Socket is connected",
+		[ENOTCONN] = "Socket not connected",
+		[ESHUTDOWN] = "Cannot send after socket shutdown",
+		[EALREADY] = "Operation already in progress",
+		[EINPROGRESS] = "Operation in progress",
+		[ESTALE] = "Stale file handle",
+		[EUCLEAN] = "Data consistency error",
+		[ENAVAIL] = "Resource not available",
+		[EREMOTEIO] = "Remote I/O error",
+		[EDQUOT] = "Quota exceeded",
+		[ENOMEDIUM] = "No medium found",
+		[EMEDIUMTYPE] = "Wrong medium type",
+		[EMULTIHOP] = "Multihop attempted",
+		[ENOKEY] = "Required key not available",
+		[EKEYEXPIRED] = "Key has expired",
+		[EKEYREVOKED] = "Key has been revoked",
+		[EKEYREJECTED] = "Key was rejected by service",
+	};
+
+	return table[errnum];
+}
+
+int strerror_r(int errnum, char *buf, size_t buflen)
+{
+	const char *msg = strerror(errnum);
+	size_t msglen = strlen(msg) + 1;
+
+	if (buflen < msglen) {
+		return ERANGE;
+	}
+
+	memcpy(buf, msg, msglen);
+	return 0;
+}
+
+weak char *strerror_l(int errnum, locale_t unused locale)
+{
+	return strerror(errnum);
+}
diff --git a/lib/libc/string/strlcat.c b/lib/libc/string/strlcat.c
new file mode 100644
index 00000000..a2c333e0
--- /dev/null
+++ b/lib/libc/string/strlcat.c
@@ -0,0 +1,19 @@
+#include <string.h>
+
+size_t strlcat(char *restrict dst, const char *restrict src, size_t dstsize)
+{
+	size_t dlen = strlen(dst);
+	size_t slen = strlen(src);
+	size_t n = dstsize - dlen - 1;
+
+	if (n == 0)
+		return dlen + slen;
+
+	if (n > slen)
+		n = slen;
+
+	memcpy(dst + dlen, src, n);
+	dst[dlen + n] = '\0';
+
+	return dlen + n;
+}
diff --git a/lib/libc/string/strlcpy.c b/lib/libc/string/strlcpy.c
new file mode 100644
index 00000000..2f2f6a3b
--- /dev/null
+++ b/lib/libc/string/strlcpy.c
@@ -0,0 +1,16 @@
+#include <string.h>
+
+size_t strlcpy(char *restrict dst, const char *restrict src, size_t dstsize)
+{
+	size_t srclen = strlen(src);
+
+	if (dstsize == 0) {
+		return srclen;
+	}
+
+	size_t copylen = srclen < dstsize - 1 ? srclen : dstsize - 1;
+	memcpy(dst, src, copylen);
+	dst[copylen] = '\0';
+
+	return srclen;
+}
diff --git a/lib/libc/string/strlen.c b/lib/libc/string/strlen.c
new file mode 100644
index 00000000..0eb222fa
--- /dev/null
+++ b/lib/libc/string/strlen.c
@@ -0,0 +1,14 @@
+#include <stddef.h>
+
+size_t strlen(const char *str)
+{
+	size_t len = 0;
+
+	if (str == NULL)
+		return 0;
+
+	while (*str++)
+		len++;
+
+	return len;
+}
diff --git a/lib/libc/string/strncat.c b/lib/libc/string/strncat.c
new file mode 100644
index 00000000..ce0d8e24
--- /dev/null
+++ b/lib/libc/string/strncat.c
@@ -0,0 +1,19 @@
+#include <string.h>
+
+char *strncat(char *restrict s1, const char *restrict s2, size_t n)
+{
+	char *dest = s1;
+	const char *src = s2;
+
+	while (*dest != '\0')
+		dest++;
+
+	while (*src != '\0' && n > 0) {
+		*dest++ = *src++;
+		n--;
+	}
+
+	*dest = '\0';
+
+	return s1;
+}
diff --git a/lib/libc/string/strncmp.c b/lib/libc/string/strncmp.c
new file mode 100644
index 00000000..2fbc2395
--- /dev/null
+++ b/lib/libc/string/strncmp.c
@@ -0,0 +1,16 @@
+#include <stddef.h>
+
+int strncmp(const char *s1, const char *s2, size_t n)
+{
+	const unsigned char *p1 = (const unsigned char *)s1;
+	const unsigned char *p2 = (const unsigned char *)s2;
+
+	while (n-- > 0) {
+		if (*p1 != *p2 || *p1 == '\0')
+			return *p1 - *p2;
+		p1++;
+		p2++;
+	}
+
+	return 0;
+}
diff --git a/lib/libc/string/strncpy.c b/lib/libc/string/strncpy.c
new file mode 100644
index 00000000..c43b88c8
--- /dev/null
+++ b/lib/libc/string/strncpy.c
@@ -0,0 +1,16 @@
+#include <stddef.h>
+
+char *strncpy(char *restrict s1, const char *restrict s2, size_t n)
+{
+	char *result = s1;
+
+	while (n > 0 && *s2 != '\0') {
+		*s1++ = *s2++;
+		n--;
+	}
+
+	if (n > 0)
+		*s1 = '\0';
+
+	return result;
+}
diff --git a/lib/libc/string/strndup.c b/lib/libc/string/strndup.c
new file mode 100644
index 00000000..70e10501
--- /dev/null
+++ b/lib/libc/string/strndup.c
@@ -0,0 +1,15 @@
+#include <stdlib.h>
+#include <string.h>
+
+char *strndup(const char *s, size_t size)
+{
+	char *result = malloc(size + 1);
+
+	if (result == NULL)
+		return NULL;
+
+	memcpy(result, s, size);
+	result[size] = '\0';
+
+	return result;
+}
diff --git a/lib/libc/string/strnlen.c b/lib/libc/string/strnlen.c
new file mode 100644
index 00000000..11da22ec
--- /dev/null
+++ b/lib/libc/string/strnlen.c
@@ -0,0 +1,11 @@
+#include <stddef.h>
+
+size_t strnlen(const char *s, size_t maxlen)
+{
+	size_t len = 0;
+
+	while (*s++ && len < maxlen)
+		len++;
+
+	return len;
+}
diff --git a/lib/libc/string/strpbrk.c b/lib/libc/string/strpbrk.c
new file mode 100644
index 00000000..21d6507f
--- /dev/null
+++ b/lib/libc/string/strpbrk.c
@@ -0,0 +1,16 @@
+#include <stddef.h>
+
+char *strpbrk(const char *s1, const char *s2)
+{
+	while (*s1 != '\0') {
+		const char *p = s2;
+		while (*p != '\0') {
+			if (*s1 == *p)
+				return (char *)s1;
+			p++;
+		}
+		s1++;
+	}
+
+	return NULL;
+}
diff --git a/lib/libc/string/strrchr.c b/lib/libc/string/strrchr.c
new file mode 100644
index 00000000..d2807569
--- /dev/null
+++ b/lib/libc/string/strrchr.c
@@ -0,0 +1,12 @@
+#include <stddef.h>
+
+char *strrchr(const char *s, int c)
+{
+	const char *last = NULL;
+	while (*s != '\0') {
+		if (*s == c)
+			last = s;
+		s++;
+	}
+	return (char *)last;
+}
diff --git a/lib/libc/string/strspn.c b/lib/libc/string/strspn.c
new file mode 100644
index 00000000..78277ae7
--- /dev/null
+++ b/lib/libc/string/strspn.c
@@ -0,0 +1,12 @@
+#include <stddef.h>
+#include <string.h>
+
+size_t strspn(const char *s1, const char *s2)
+{
+	size_t count = 0;
+	while (*s1 != '\0' && strchr(s2, *s1) != NULL) {
+		count++;
+		s1++;
+	}
+	return count;
+}
diff --git a/lib/libc/string/strstr.c b/lib/libc/string/strstr.c
new file mode 100644
index 00000000..c3e2d5dd
--- /dev/null
+++ b/lib/libc/string/strstr.c
@@ -0,0 +1,27 @@
+#include <stddef.h>
+
+char *strstr(const char *s1, const char *s2)
+{
+	const char *p = s1;
+	const char *q = s2;
+
+	if (*q == '\0')
+		return (char *)p;
+
+	while (*p != '\0') {
+		const char *pp = p;
+		const char *qq = q;
+
+		while (*pp == *qq && *pp != '\0') {
+			pp++;
+			qq++;
+		}
+
+		if (*qq == '\0')
+			return (char *)p;
+
+		p++;
+	}
+
+	return NULL;
+}
diff --git a/lib/libc/string/strtok.c b/lib/libc/string/strtok.c
new file mode 100644
index 00000000..33d0d685
--- /dev/null
+++ b/lib/libc/string/strtok.c
@@ -0,0 +1,40 @@
+#include <stddef.h>
+#include <string.h>
+
+char *strtok(char *restrict s, const char *restrict sep)
+{
+	static _Thread_local char *state = NULL;
+
+	if (s != NULL) {
+		state = s;
+	}
+
+	if (state == NULL) {
+		return NULL;
+	}
+
+	char *token = state;
+	while (*token && strchr(sep, *token)) {
+		token++;
+	}
+
+	if (*token == '\0') {
+		state = NULL;
+		return NULL;
+	}
+
+	char *start = token;
+
+	while (*token && strchr(sep, *token) == NULL) {
+		token++;
+	}
+
+	if (*token) {
+		*token = '\0';
+		state = token + 1;
+	} else {
+		state = NULL;
+	}
+
+	return start;
+}
diff --git a/lib/libc/string/strtok_r.c b/lib/libc/string/strtok_r.c
new file mode 100644
index 00000000..57555b14
--- /dev/null
+++ b/lib/libc/string/strtok_r.c
@@ -0,0 +1,37 @@
+#include <string.h>
+
+char *strtok_r(char *restrict s, const char *restrict sep,
+	       char **restrict state)
+{
+	if (s == NULL) {
+		s = *state;
+	}
+
+	if (s == NULL) {
+		return NULL;
+	}
+
+	while (*s && strchr(sep, *s)) {
+		s++;
+	}
+
+	if (*s == '\0') {
+		*state = NULL;
+		return NULL;
+	}
+
+	char *start = s;
+
+	while (*s && strchr(sep, *s) == NULL) {
+		s++;
+	}
+
+	if (*s) {
+		*s = '\0';
+		*state = s + 1;
+	} else {
+		*state = NULL;
+	}
+
+	return start;
+}
diff --git a/lib/libc/string/strxfrm.c b/lib/libc/string/strxfrm.c
new file mode 100644
index 00000000..d62d0a96
--- /dev/null
+++ b/lib/libc/string/strxfrm.c
@@ -0,0 +1,18 @@
+#include <libc.h>
+#include <string.h>
+
+size_t strxfrm(char *restrict s1, const char *restrict s2, size_t n)
+{
+	size_t len = strlen(s2);
+
+	if (n > len)
+		strcpy(s1, s2);
+
+	return len;
+}
+
+weak size_t strxfrm_l(char *restrict s1, const char *restrict s2, size_t n,
+		      locale_t unused locale)
+{
+	return strxfrm(s1, s2, n);
+}