From c65395be643cad64e11d1b0763d7ea048da3dc84 Mon Sep 17 00:00:00 2001
From: Xavier Del Campo Romero <xavi.dcr@tutanota.com>
Date: Sun, 8 Nov 2020 17:37:16 +0100
Subject: [PATCH] Implement strerror(3) and strerror_r(3)

Error descriptions obtained from include/errno.h.
---
 libpsx/src/libc/error.c | 113 +++++++++++++++++++++++++++++++++++++---
 1 file changed, 105 insertions(+), 8 deletions(-)

diff --git a/libpsx/src/libc/error.c b/libpsx/src/libc/error.c
index 6863b2f..ab5fe5b 100644
--- a/libpsx/src/libc/error.c
+++ b/libpsx/src/libc/error.c
@@ -1,19 +1,116 @@
+#include <errno.h>
 #include <stdio.h>
 #include <string.h>
 
-static char strerror_not_implemented[64];
+static const char *const str[] =
+{
+	[EPERM] = "Operation not permitted",
+	[ENOENT] = "No such file or directory",
+	[ESRCH] = "No such process",
+	[EINTR] = "Interrupted system call",
+	[EIO] = "Input/output error",
+	[ENXIO] = "Device not configured",
+	[E2BIG] = "Argument list too long",
+	[ENOEXEC] = "Exec format error",
+	[EBADF] = "Bad file descriptor",
+	[ECHILD] = "No child processes",
+	[EDEADLK] = "Resource deadlock avoided",
+	[ENOMEM] = "Cannot allocate memory",
+	[EACCES] = "Permission denied",
+	[EFAULT] = "Bad address",
+	[ENOTBLK] = "Block device required",
+	[EBUSY] = "Device busy",
+	[EEXIST] = "File exists",
+	[EXDEV] = "Cross-device link",
+	[ENODEV] = "Operation not supported by device",
+	[ENOTDIR] = "Not a directory",
+	[EISDIR] = "Is a directory",
+	[EINVAL] = "Invalid argument",
+	[ENFILE] = "Too many open files in system",
+	[EMFILE] = "Too many open files",
+	[ENOTTY] = "Inappropriate ioctl for device",
+	[ETXTBSY] = "Text file busy",
+	[EFBIG] = "File too large",
+	[ENOSPC] = "No space left on device",
+	[ESPIPE] = "Illegal seek",
+	[EROFS] = "Read-only file system",
+	[EMLINK] = "Too many links",
+	[EPIPE] = "Broken pipe",
+	[EDOM] = "Numerical argument out of domain",
+	[ERANGE] = "Result too large or too small",
+	[EAGAIN] = "Resource temporarily unavailable",
+	[EWOULDBLOCK] = "Operation would block",
+	[EINPROGRESS] = "Operation now in progress",
+	[EALREADY] = "Operation already in progress",
+	[ENOTSOCK] = "Socket operation on non-socket",
+	[EDESTADDRREQ] = "Destination address required",
+	[EMSGSIZE] = "Message too long",
+	[EPROTOTYPE] = "Protocol wrong type for socket",
+	[ENOPROTOOPT] = "Protocol option not available",
+	[EPROTONOSUPPORT] = "Protocol not supported",
+	[ESOCKTNOSUPPORT] = "Socket type not supported",
+	[EOPNOTSUPP] = "Operation not supported",
+	[EPFNOSUPPORT] = "Protocol family not supported",
+	[EAFNOSUPPORT] = "Address family not supported by protocol family",
+	[EADDRINUSE] = "Address already in use",
+	[EADDRNOTAVAIL] = "Can't assign requested address",
+	[ENETDOWN] = "Network is down",
+	[ENETUNREACH] = "Network is unreachable",
+	[ENETRESET] = "Network dropped connection on reset",
+	[ECONNABORTED] = "Software caused connection abort",
+	[ECONNRESET] = "Connection reset by peer",
+	[ENOBUFS] = "No buffer space available",
+	[EISCONN] = "Socket is already connected",
+	[ENOTCONN] = "Socket is not connected",
+	[ESHUTDOWN] = "Can't send after socket shutdown",
+	[ETOOMANYREFS] = "Too many references: can't splice",
+	[ETIMEDOUT] = "Operation timed out",
+	[ECONNREFUSED] = "Connection refused",
+	[ELOOP] = "Too many levels of symbolic links",
+	[ENAMETOOLONG] = "File name too long",
+	[EHOSTDOWN] = "Host is down",
+	[EHOSTUNREACH] = "No route to host",
+	[ENOTEMPTY] = "Directory not empty",
+	[EUSERS] = "Too many users",
+	[EDQUOT] = "Disc quota exceeded",
+	[ESTALE] = "Stale NFS file handle",
+	[EREMOTE] = "Too many levels of remote in path",
+	[ENOLCK] = "No locks available",
+	[ENOSYS] = "Function not implemented",
+	[EIDRM] = "Identifier removed",
+	[ENOMSG] = "No message of desired type",
+	[EOVERFLOW] = "Value too large to be stored in data type",
+	[EILSEQ] = "Illegal byte sequence",
+	[ENOTSUP] = "Not supported",
+	[ECANCELED] = "Operation canceled",
+	[EBADMSG] = "Bad or Corrupt message",
+	[ENODATA] = "No message available",
+	[ENOSR] = "No STREAM resources",
+	[ENOSTR] = "Not a STREAM",
+	[ETIME] = "STREAM ioctl timeout",
+	[EMULTIHOP] = "Multihop attempted",
+	[ENOLINK] = "Link has been severed",
+	[EPROTO] = "Protocol error"
+};
 
 char *strerror(int errnum)
 {
-	strerror_r(errnum, strerror_not_implemented, 64);
-	
-	return strerror_not_implemented;
+	static char deferr[sizeof "Unknown error -2147483648"];
+
+	if (errnum < sizeof str / sizeof *str)
+		return (char *)str[errnum];
+
+	snprintf(deferr, sizeof deferr, "Unknown error %d", errnum);
+	return deferr;
 }
 
 int strerror_r(int errnum, char *strerrbuf, size_t buflen)
 {
-	snprintf(strerrbuf, buflen,
-		"strerror(%d)", errnum);
-	
-	return 0;
+	if (errnum < sizeof str / sizeof *str) {
+		snprintf(strerrbuf, buflen, "%s", str[errnum]);
+		return strlen(str[errnum]);
+	}
+
+	snprintf(strerrbuf, buflen, "Unknown error %d", errnum);
+	return -1;
 }