Add sys_nerr and sys_errlist.

Also keep the canonical errno list in LibC for now. The kernel gets it
from there. This makes building 3rd party code easier.

..also fix broken strchr().

Kernel/errno.h

@@ -1,40 +1,3 @@
 #pragma once
 
-#define EPERM      1    // Operation not permitted
-#define ENOENT     2    // No such file or directory
-#define ESRCH      3    // No such process
-#define EINTR      4    // Interrupted system call
-#define EIO        5    // I/O error
-#define ENXIO      6    // No such device or address
-#define E2BIG      7    // Argument list too long
-#define ENOEXEC    8    // Exec format error
-#define EBADF      9    // Bad file number
-#define ECHILD    10    // No child processes
-#define EAGAIN    11    // Try again
-#define ENOMEM    12    // Out of memory
-#define EACCES    13    // Permission denied
-#define EFAULT    14    // Bad address
-#define ENOTBLK   15    // Block device required
-#define EBUSY     16    // Device or resource busy
-#define EEXIST    17    // File exists
-#define EXDEV     18    // Cross-device link
-#define ENODEV    19    // No such device
-#define ENOTDIR   20    // Not a directory
-#define EISDIR    21    // Is a directory
-#define EINVAL    22    // Invalid argument
-#define ENFILE    23    // File table overflow
-#define EMFILE    24    // Too many open files
-#define ENOTTY    25    // Not a typewriter
-#define ETXTBSY   26    // Text file busy
-#define EFBIG     27    // File too large
-#define ENOSPC    28    // No space left on device
-#define ESPIPE    29    // Illegal seek
-#define EROFS     30    // Read-only file system
-#define EMLINK    31    // Too many links
-#define EPIPE     32    // Broken pipe
-#define EDOM      33    // Math argument out of domain of func
-#define ERANGE    34    // Math result not representable
-#define ENAMETOOLONG 36 // Name too long
-#define ELOOP     40    // Too many symbolic links
-#define EOVERFLOW 75    // Value too large for defined data type
-#define ENOTIMPL 999    // Not implemented
+#include <LibC/errno_numbers.h>

LibC/errno.h

@@ -1,7 +1,7 @@
 #pragma once
 
 #include <sys/cdefs.h>
-#include <Kernel/errno.h>
+#include <errno_numbers.h>
 
 #define __RETURN_WITH_ERRNO(rc, good_ret, bad_ret) \
     do { \
@@ -16,7 +16,8 @@
 
 __BEGIN_DECLS
 
+extern const char* sys_errlist[];
+extern int sys_nerr;
 extern int errno;
 
 __END_DECLS
-

LibC/string.cpp

@@ -115,12 +115,13 @@ char* strncpy(char* dest, const char* src, size_t n)
 
 char* strchr(const char* str, int c)
 {
-    if (!str)
-        return nullptr;
-    char* ptr = (char*)str;
-    while (*ptr && *ptr != c)
-        ++ptr;
-    return ptr;
+    char ch = c;
+    for (;; ++str) {
+        if (*str == ch)
+            return (char*)str;
+        if (!*str)
+            return nullptr;
+    }
 }
 
 char* strrchr(const char* str, int ch)
@@ -154,50 +155,22 @@ char* strncat(char *dest, const char *src, size_t n)
     return dest;
 }
 
+const char* sys_errlist[] = {
+#undef __ERROR
+#define __ERROR(a, b) #b,
+    __ENUMERATE_ALL_ERRORS
+#undef __ERROR
+};
+int sys_nerr = __errno_count;
+
 char* strerror(int errnum)
 {
-    switch (errnum) {
-    case 0: return "No error";
-    case EPERM: return "Operation not permitted";
-    case ENOENT: return "No such file or directory";
-    case ESRCH: return "No such process";
-    case EINTR: return "Interrupted syscall";
-    case EIO: return "I/O error";
-    case ENXIO: return "No such device/address";
-    case E2BIG: return "Argument list too long";
-    case ENOEXEC: return "Exec format error";
-    case EBADF: return "Bad fd number";
-    case ECHILD: return "No child processes";
-    case EAGAIN: return "Try again";
-    case ENOMEM: return "Out of memory";
-    case EACCES: return "Access denied";
-    case EFAULT: return "Bad address";
-    case ENOTBLK: return "Not a block device";
-    case EBUSY: return "Resource busy";
-    case EEXIST: return "File already exists";
-    case EXDEV: return "Cross-device link";
-    case ENODEV: return "No such device";
-    case ENOTDIR: return "Not a directory";
-    case EISDIR: return "Is a directory";
-    case EINVAL: return "Invalid argument";
-    case ENFILE: return "File table overflow";
-    case EMFILE: return "Too many open files";
-    case ENOTTY: return "Not a TTY";
-    case ETXTBSY: return "Text file busy";
-    case EFBIG: return "File too big";
-    case ENOSPC: return "No space left";
-    case ESPIPE: return "Illegal seek";
-    case EROFS: return "File system is read-only";
-    case EMLINK: return "Too many links";
-    case EPIPE: return "Broken pipe";
-    case EDOM: return "Math argument out of domain";
-    case ERANGE: return "Math result not representable";
-    case ENAMETOOLONG: return "Name too long";
-    case EOVERFLOW: return "Value too large for data type";
-    case ENOTIMPL: return "Not implemented";
+    if (errnum >= __errno_count) {
+        printf("strerror() missing string for errnum=%d\n", errnum);
+        return "Unknown error";
     }
-    printf("strerror() missing string for errnum=%d\n", errnum);
-    return "Unknown error";
+    return (char*)sys_errlist[errnum];
+
 }
 
 }