fix: define S_ISREG on Windows

- detect whether POSIX-style macros exist before using them
- fall back to the MSVC _S_IF* constants when needed

Author: onthfixe

src/stdlib_system.c

@@ -9,6 +9,13 @@
 #ifdef _WIN32
 #include <direct.h>
 #include <windows.h>
+#ifndef S_ISREG
+#if defined(S_IFMT) && defined(S_IFREG)
+#define S_ISREG(mode) (((mode) & S_IFMT) == S_IFREG)
+#elif defined(_S_IFMT) && defined(_S_IFREG)
+#define S_ISREG(mode) (((mode) & _S_IFMT) == _S_IFREG)
+#endif
+#endif /* ifndef S_ISREG */
 #else
 #include <unistd.h>
 #endif /* ifdef _WIN32 */
@@ -17,54 +24,58 @@
 // Always Uses `strerr` on unix.
 // if `winapi` is `false`, uses the usual `strerr` on windows.
 // If `winapi` is `true`, uses `FormatMessageA`(from windows.h) on windows.
-char* stdlib_strerror(size_t* len, bool winapi){
+char *stdlib_strerror(size_t *len, bool winapi)
+{
 
-    if (winapi) {
+    if (winapi)
+    {
 #ifdef _WIN32
-    LPSTR err = NULL;
-    DWORD dw = GetLastError();
-
-    FormatMessageA(
-    FORMAT_MESSAGE_ALLOCATE_BUFFER |
-    FORMAT_MESSAGE_FROM_SYSTEM |
-    FORMAT_MESSAGE_IGNORE_INSERTS,
-    NULL,
-    dw,
-    MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
-    (LPSTR) &err,
-    0,
-    NULL);
-
-    *len = strlen(err);
-    return (char*) err;
+        LPSTR err = NULL;
+        DWORD dw = GetLastError();
+
+        FormatMessageA(
+            FORMAT_MESSAGE_ALLOCATE_BUFFER |
+                FORMAT_MESSAGE_FROM_SYSTEM |
+                FORMAT_MESSAGE_IGNORE_INSERTS,
+            NULL,
+            dw,
+            MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
+            (LPSTR)&err,
+            0,
+            NULL);
+
+        *len = strlen(err);
+        return (char *)err;
 
 #endif /* ifdef _WIN32 */
     }
 
-    char* err = strerror(errno);
+    char *err = strerror(errno);
     *len = strlen(err);
     return err;
 }
 
 // Wrapper to the platform's `mkdir`(make directory) call.
 // Uses `mkdir` on unix, `_mkdir` on windows.
 // Returns 0 if successful, otherwise returns the `errno`.
-int stdlib_make_directory(const char* path){
+int stdlib_make_directory(const char *path)
+{
     int code;
 #ifdef _WIN32
     code = _mkdir(path);
 #else
     // Default mode 0777
     code = mkdir(path, 0777);
 #endif /* ifdef _WIN32 */
-    
+
     return (!code) ? 0 : errno;
 }
 
 // Wrapper to the platform's `rmdir`(remove directory) call.
 // Uses `rmdir` on unix, `_rmdir` on windows.
 // Returns 0 if successful, otherwise returns the `errno`.
-int stdlib_remove_directory(const char* path){
+int stdlib_remove_directory(const char *path)
+{
     int code;
 #ifdef _WIN32
     code = _rmdir(path);
@@ -77,13 +88,15 @@ int stdlib_remove_directory(const char* path){
 // Wrapper to the platform's `getcwd`(get current working directory) call.
 // Uses `getcwd` on unix, `_getcwd` on windows.
 // Returns the cwd, sets the length of cwd and the `stat` of the operation.
-char* stdlib_get_cwd(size_t* len, int* stat){
+char *stdlib_get_cwd(size_t *len, int *stat)
+{
     *stat = 0;
 #ifdef _WIN32
-    char* buffer;
+    char *buffer;
     buffer = _getcwd(NULL, 0);
 
-    if (buffer == NULL) {
+    if (buffer == NULL)
+    {
         *stat = errno;
         return NULL;
     }
@@ -92,13 +105,14 @@ char* stdlib_get_cwd(size_t* len, int* stat){
     return buffer;
 #else
     char buffer[PATH_MAX + 1];
-    if (!getcwd(buffer, sizeof(buffer))) {
+    if (!getcwd(buffer, sizeof(buffer)))
+    {
         *stat = errno;
     }
 
     *len = strlen(buffer);
 
-    char* res = malloc(*len);
+    char *res = malloc(*len);
     strncpy(res, buffer, *len);
 
     return res;
@@ -108,21 +122,23 @@ char* stdlib_get_cwd(size_t* len, int* stat){
 // Wrapper to the platform's `chdir`(change directory) call.
 // Uses `chdir` on unix, `_chdir` on windows.
 // Returns 0 if successful, otherwise returns the `errno`.
-int stdlib_set_cwd(char* path) {
+int stdlib_set_cwd(char *path)
+{
     int code;
 #ifdef _WIN32
     code = _chdir(path);
 #else
     code = chdir(path);
 #endif /* ifdef _WIN32 */
-    
+
     return (code == -1) ? errno : 0;
 }
 
 // Wrapper to the platform's `stat`(status of path) call.
 // Uses `lstat` on unix, `GetFileAttributesA` on windows.
 // Returns the `type` of the path, and sets the `stat`(if any errors).
-int stdlib_exists(const char* path, int* stat){
+int stdlib_exists(const char *path, int *stat)
+{
     // All the valid types
     const int fs_type_unknown = 0;
     const int fs_type_regular_file = 1;
@@ -135,40 +151,54 @@ int stdlib_exists(const char* path, int* stat){
 #ifdef _WIN32
     DWORD attrs = GetFileAttributesA(path);
 
-    if (attrs == INVALID_FILE_ATTRIBUTES) {
-        *stat = (int) GetLastError();
+    if (attrs == INVALID_FILE_ATTRIBUTES)
+    {
+        *stat = (int)GetLastError();
         return fs_type_unknown;
     }
 
     // Let's assume it is a regular file
     type = fs_type_regular_file;
 
-    if (attrs & FILE_ATTRIBUTE_REPARSE_POINT) type = fs_type_symlink;
-    if (attrs & FILE_ATTRIBUTE_DIRECTORY) type = fs_type_directory;
+    if (attrs & FILE_ATTRIBUTE_REPARSE_POINT)
+        type = fs_type_symlink;
+    if (attrs & FILE_ATTRIBUTE_DIRECTORY)
+        type = fs_type_directory;
 #else
     struct stat buf = {0};
     int status;
     status = lstat(path, &buf);
 
-    if (status == -1) {
+    if (status == -1)
+    {
         // `lstat` failed
         *stat = errno;
         return fs_type_unknown;
     }
 
-    switch (buf.st_mode & S_IFMT) {
-        case S_IFREG: type = fs_type_regular_file; break;
-        case S_IFDIR: type = fs_type_directory;    break;
-        case S_IFLNK: type = fs_type_symlink;      break;
-        default:      type = fs_type_unknown;      break;
+    switch (buf.st_mode & S_IFMT)
+    {
+    case S_IFREG:
+        type = fs_type_regular_file;
+        break;
+    case S_IFDIR:
+        type = fs_type_directory;
+        break;
+    case S_IFLNK:
+        type = fs_type_symlink;
+        break;
+    default:
+        type = fs_type_unknown;
+        break;
     }
 #endif /* ifdef _WIN32 */
     return type;
 }
 
 // `stat` and `_stat` follow symlinks automatically.
 // so no need for winapi functions.
-bool stdlib_is_file(const char* path) {
+bool stdlib_is_file(const char *path)
+{
 #ifdef _WIN32
     struct _stat buf = {0};
     return _stat(path, &buf) == 0 && S_ISREG(buf.st_mode);