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| -rw-r--r-- | docs/reference.rst | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/docs/reference.rst b/docs/reference.rst index 6094e13c..6cd3c646 100644 --- a/docs/reference.rst +++ b/docs/reference.rst @@ -277,13 +277,38 @@ Protocol Buffers wire types. These are used with `pb_encode_tag`_. :: PB_WT_32BIT = 5 } pb_wire_type_t; +PB_GET_ERROR +------------ +Get the current error message from a stream, or a placeholder string if +there is no error message:: + #define PB_GET_ERROR(stream) (string expression) +This should be used for printing errors, for example:: + if (!pb_decode(...)) + { + printf("Decode failed: %s\n", PB_GET_ERROR(stream)); + } + +The macro only returns pointers to constant strings (in code memory), +so that there is no need to release the returned pointer. +PB_RETURN_ERROR +--------------- +Set the error message and return false:: + #define PB_RETURN_ERROR(stream,msg) (sets error and returns false) +This should be used to handle error conditions inside nanopb functions +and user callback functions:: + + if (error_condition) + { + PB_RETURN_ERROR(stream, "something went wrong"); + } +The *msg* parameter must be a constant string. |