lib: strictly type function return status enumerations

[babeltrace.git] / include / babeltrace2 / func-status.h

diff --git a/include/babeltrace2/func-status.h b/include/babeltrace2/func-status.h
new file mode 100644 (file)
index 0000000..60b6862
--- /dev/null
+++ b/include/babeltrace2/func-status.h
@@ -0,0 +1,90 @@
+/*
+ * No include guards here: this header is included by a public header to
+ * get the `__BT_FUNC_STATUS_*` definitions locally, and then
+ * <babeltrace2/undef-func-status.h> is included at the end of the
+ * header to undefine all those definitions.
+ *
+ * If we forget to include <babeltrace2/undef-func-status.h> at the end
+ * of a public header, we want to get the "redefined" compiler warning
+ * to catch it.
+ */
+
+/*
+ * Copyright (c) 2019 Philippe Proulx <pproulx@efficios.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+/*
+ * This is just extra protection, in case the user tries to include
+ * <babeltrace2/func-status.h> in user code: this is a redminder that
+ * this header is reserved for internal use.
+ *
+ * The correct way for a public header to include this is:
+ *
+ *     #define __BT_FUNC_STATUS_ENABLE
+ *     #include <babeltrace2/func-status.h>
+ *     #undef __BT_FUNC_STATUS_ENABLE
+ */
+#ifndef __BT_FUNC_STATUS_ENABLE
+# error Do NOT include <babeltrace2/func-status.h> in user code.
+#endif
+
+/*
+ * This is NOT part of the API.
+ *
+ * Do NOT use a `__BT_FUNC_STATUS_*` value in user code: this inhibits
+ * precious type checking.
+ */
+
+/* Value is too large for the given data type */
+#define __BT_FUNC_STATUS_OVERFLOW              -75
+
+/* Invalid query parameters */
+#define __BT_FUNC_STATUS_INVALID_PARAMS                -24
+
+/* Invalid query object */
+#define __BT_FUNC_STATUS_INVALID_OBJECT                -23
+
+/* Memory allocation error */
+#define __BT_FUNC_STATUS_MEMORY_ERROR          -12
+
+/* Plugin loading error */
+#define __BT_FUNC_STATUS_LOADING_ERROR         -2
+
+/* General error */
+#define __BT_FUNC_STATUS_ERROR                 -1
+
+/* Saul Goodman */
+#define __BT_FUNC_STATUS_OK                    0
+
+/* End of iteration/consumption */
+#define __BT_FUNC_STATUS_END                   1
+
+/* Something can't be found */
+#define __BT_FUNC_STATUS_NOT_FOUND             2
+
+/* Try operation again later */
+#define __BT_FUNC_STATUS_AGAIN                 11
+
+/* Unsupported operation */
+#define __BT_FUNC_STATUS_UNSUPPORTED           95
+
+/* Object is canceled */
+#define __BT_FUNC_STATUS_CANCELED              125