Add write permissions check on output folder

src/build_settings.cpp

@@ -1504,7 +1504,8 @@ gb_internal bool init_build_paths(String init_filename) {
 		if (build_context.metrics.os == TargetOs_windows) {
 			output_extension = STR_LIT("exe");
 		} else if (build_context.cross_compiling && selected_target_metrics->metrics == &target_essence_amd64) {
-			output_extension = make_string(nullptr, 0);
+			// Do nothing: we don't want the .bin extension
+			// when cross compiling
 		} else if (path_is_directory(last_path_element(bc->build_paths[BuildPath_Main_Package].basename))) {
 			// Add .bin extension to avoid collision
 			// with package directory name
@@ -1624,6 +1625,22 @@ gb_internal bool init_build_paths(String init_filename) {
 		return false;
 	}
 
+	if (path_is_directory(bc->build_paths[BuildPath_Output])) {
+		String output_file = path_to_string(ha, bc->build_paths[BuildPath_Output]);
+		defer (gb_free(ha, output_file.text));
+		gb_printf_err("Output path %.*s is a directory.\n", LIT(output_file));
+		return false;
+	}
+	//nocheckin char const *pathname = (char *)bc->build_paths[BuildPath_Output].basename.text;
+
+	if (!write_directory(bc->build_paths[BuildPath_Output].basename)) {
+		String output_file = path_to_string(ha, bc->build_paths[BuildPath_Output]);
+		defer (gb_free(ha, output_file.text));
+		gb_printf_err("No write permissions for output path: %.*s\n", LIT(output_file));
+		return false;
+	}
+
+
 	if (bc->target_features_string.len != 0) {
 		enable_target_feature({}, bc->target_features_string);
 	}

src/path.cpp

@@ -419,7 +419,43 @@ gb_internal ReadDirectoryError read_directory(String path, Array<FileInfo> *fi)
 
 	return ReadDirectory_None;
 }
+
+
 #else
 #error Implement read_directory
 #endif
 
+#if !defined(GB_SYSTEM_WINDOWS)
+gb_internal bool write_directory(String path) {
+	char const *pathname = (char *) path.text;
+
+	if (access(pathname, W_OK) < 0) {
+		return false;
+	}
+
+	return true;
+}
+#else
+gb_internal bool write_directory(String path) {
+	String16wstr = string_to_string16(heap_allocator(), path);
+	LPCWSTR wdirectory_name = wstr.text;
+
+	HANDLE directory = CreateFileW(wdirectory_name,
+			GENERIC_WRITE,
+			0,
+			NULL,
+			OPEN_EXISTING,
+			FILE_FLAG_BACKUP_SEMANTICS,
+			NULL);
+
+	if (directory == INVALID_HANDLE_VALUE) {
+		DWORD error_code = GetLastError();
+		if (error_code == ERROR_ACCESS_DENIED) {
+			return false;
+		}
+	}
+
+	CloseHandle(directory);
+	return true;
+}
+#endif