From 680b8925a1c8c22dfd4776debbee66e4b7856fb6 Mon Sep 17 00:00:00 2001
From: skye <exoskye@duck.com>
Date: Sat, 10 Jun 2023 14:04:14 +0100
Subject: [PATCH] winapi: Implement all `direct.h` functions apart from path
 manipulation

`fnmerge` and `fnsplit` haven't been implemented since I noticed inconsistencies in the documentation relating to them, for now I simply have empty function definitions in the form described by  https://www.digitalmars.com/rtl/direct.html (ie no `_` prefix)
The status of other functions is as follows:
`_chdir`, `_chdrive`: impossible to implement, succeeds without an error code, or change of state in the Xbox
`_getcwd`, `_getwd`: impossible to implement, return NULL pointers and sets `errno` to `-EINVAL`
`_getdrive`: as before, impossible to implement - returns `0` and sets `errno` to `-EINVAL` (this is the error state described by a combo of MS public documentation and digital mars docs)
`_searchpath`: impossible to implement since there is no PATH variable on the Xbox
`_mkdir`, `_rmdir`: implemented, testing required, however
---
 lib/xboxrt/libc_extensions/direct.c | 111 ++++++++++++++++++++++++++++
 lib/xboxrt/libc_extensions/direct.h |  10 +++
 2 files changed, 121 insertions(+)
 create mode 100644 lib/xboxrt/libc_extensions/direct.c

diff --git a/lib/xboxrt/libc_extensions/direct.c b/lib/xboxrt/libc_extensions/direct.c
new file mode 100644
index 000000000..96ae4ee19
--- /dev/null
+++ b/lib/xboxrt/libc_extensions/direct.c
@@ -0,0 +1,111 @@
+// SPDX-License-Identifier: MIT
+
+// SPDX-FileCopyrightText: 2023 ExoSkye
+
+// Part of Microsoft CRT
+
+#include <errno.h>
+#include <string.h>
+#include <stdbool.h>
+#include <windows.h>
+
+// Made referencing https://www.digitalmars.com/rtl/direct.html, retrieved 2023-06-10, copyrighted 1999-2018 by Digital Mars
+
+#define MAXPATH 80
+#define MAXDRIVE 3
+#define MAXDIR 66
+#define MAXFILE 9
+#define MAXEXT 5
+
+/*
+ * These silently succeed, since they wouldn't have any effect on the program at all
+ */
+
+int _chdir(char* path) {
+    return 0;
+}
+
+int _chdrive(int drive) {
+    return 0;
+}
+
+/*
+ * The Xbox has no concept of current working directory, so these can't work
+ */
+
+char* _getcwd(char* buffer, size_t length) {
+    errno = -EINVAL;
+    return NULL;
+}
+
+char* _getwd(char* path_name) {
+    errno = -EINVAL;
+    return NULL;
+}
+
+int _getdrive(void) {
+    errno = -EINVAL;
+    return 0;
+}
+
+/*
+ * There's no path variable on the Xbox, so this can't work
+ */
+
+char* _searchpath(const char* file) {
+    errno = -EINVAL;
+    return NULL;
+}
+
+/*
+ * Below are the only things that can work
+ */
+
+int _mkdir(const char* pathname) {
+    BOOL result = CreateDirectoryA(
+            pathname,
+            NULL
+    );
+
+    if (result == true) {
+        return 0;
+    } else {
+        DWORD err = GetLastError();
+
+        if (err == ERROR_ALREADY_EXISTS) {
+            errno = EACCES;
+        } else if (err == ERROR_PATH_NOT_FOUND) {
+            errno = ENOENT;
+        }
+
+        return -1;
+    }
+}
+
+int _rmdir(const char* pathname) {
+    BOOL result = RemoveDirectoryA(
+            pathname
+    );
+
+    if (result == true) {
+        return 0;
+    } else {
+        DWORD err = GetLastError();
+
+        if (err == ERROR_ALREADY_EXISTS) {
+            errno = EACCES;
+        } else if (err == ERROR_PATH_NOT_FOUND) {
+            errno = ENOENT;
+        }
+
+        return -1;
+    }
+}
+
+void fnmerge(char* path, const char* drive, const char* dir, const char* name, const char* ext) {
+
+}
+
+void fnsplit(const char* path, char* drive, char* dir, char* name, char* ext) {
+
+}
\ No newline at end of file
diff --git a/lib/xboxrt/libc_extensions/direct.h b/lib/xboxrt/libc_extensions/direct.h
index e7244239a..529397574 100644
--- a/lib/xboxrt/libc_extensions/direct.h
+++ b/lib/xboxrt/libc_extensions/direct.h
@@ -3,3 +3,13 @@
 // SPDX-FileCopyrightText: 2020 Jannik Vogel
 
 // Part of Microsoft CRT
+
+int _chdir(char* path);
+int _chdrive(int drive);
+char* _getcwd(char* buffer, size_t length);
+char* _getwd(char* path_name);
+int _getdrive(void);
+int _mkdir(const char* pathname);
+int _rmdir(const char* pathname);
+void _fnmerge(char* path, const char* drive, const char* dir, const char* name, const char* ext);
+char* _searchpath(const char* file);
\ No newline at end of file