From 9fdea3a35e5b0153bf4e651a1a2a1b8f3f4bad50 Mon Sep 17 00:00:00 2001 From: Petteri Aimonen Date: Sat, 25 Feb 2017 21:23:10 +0200 Subject: Make pb_check_proto3_default_value() recurse into submessages (issue #247) --- pb_encode.c | 70 +++++++++++++++++++++++++++++++++++++++++-------------------- 1 file changed, 47 insertions(+), 23 deletions(-) (limited to 'pb_encode.c') diff --git a/pb_encode.c b/pb_encode.c index 0d6e1e7e..e1f37f6d 100644 --- a/pb_encode.c +++ b/pb_encode.c @@ -27,6 +27,7 @@ static bool checkreturn encode_array(pb_ostream_t *stream, const pb_field_t *fie static bool checkreturn encode_field(pb_ostream_t *stream, const pb_field_t *field, const void *pData); static bool checkreturn default_extension_encoder(pb_ostream_t *stream, const pb_extension_t *extension); static bool checkreturn encode_extension_field(pb_ostream_t *stream, const pb_field_t *field, const void *pData); +static void *const_cast(const void *p); static bool checkreturn pb_enc_varint(pb_ostream_t *stream, const pb_field_t *field, const void *src); static bool checkreturn pb_enc_uvarint(pb_ostream_t *stream, const pb_field_t *field, const void *src); static bool checkreturn pb_enc_svarint(pb_ostream_t *stream, const pb_field_t *field, const void *src); @@ -203,30 +204,53 @@ static bool checkreturn encode_array(pb_ostream_t *stream, const pb_field_t *fie * This function implements the check for the zero value. */ static bool pb_check_proto3_default_value(const pb_field_t *field, const void *pData) { - if(PB_LTYPE(field->type) == PB_LTYPE_BYTES) + if (PB_ATYPE(field->type) == PB_ATYPE_STATIC) { - const pb_bytes_array_t *bytes = (const pb_bytes_array_t*)pData; - return bytes->size == 0; - } - else if (PB_LTYPE(field->type) == PB_LTYPE_STRING) - { - return *(const char*)pData == '\0'; - } - else if (PB_LTYPE(field->type) == PB_LTYPE_FIXED_LENGTH_BYTES) - { - /* Fixed length bytes is only empty if its length is fixed - * as 0. Which would be pretty strange, but we can check - * it anyway. */ - return field->data_size == 0; + if (PB_LTYPE(field->type) == PB_LTYPE_BYTES) + { + const pb_bytes_array_t *bytes = (const pb_bytes_array_t*)pData; + return bytes->size == 0; + } + else if (PB_LTYPE(field->type) == PB_LTYPE_STRING) + { + return *(const char*)pData == '\0'; + } + else if (PB_LTYPE(field->type) == PB_LTYPE_FIXED_LENGTH_BYTES) + { + /* Fixed length bytes is only empty if its length is fixed + * as 0. Which would be pretty strange, but we can check + * it anyway. */ + return field->data_size == 0; + } + else if (PB_LTYPE(field->type) == PB_LTYPE_SUBMESSAGE) + { + /* Check all fields in the submessage to find if any of them + * are non-zero. The comparison cannot be done byte-per-byte + * because the C struct may contain padding bytes that must + * be skipped. + */ + pb_field_iter_t iter; + if (pb_field_iter_begin(&iter, (const pb_field_t*)field->ptr, const_cast(pData))) + { + do + { + if (!pb_check_proto3_default_value(iter.pos, iter.pData)) + { + return false; + } + } while (pb_field_iter_next(&iter)); + } + return true; + } } - else + { - /* PB_LTYPE_VARINT, UVARINT, SVARINT, FIXED32, FIXED64, - * SUBMESSAGE, EXTENSION: These all have integer or pointer - * value which can be compared with 0. This does the check - * byte-by-byte to avoid the switch-cast logic used in - * pb_enc_varint(). (Casting to char* is safe with regards - * to C strict aliasing rules.) + /* Catch-all branch that does byte-per-byte comparison for zero value. + * + * This is for all pointer fields, and for static PB_LTYPE_VARINT, + * UVARINT, SVARINT, FIXED32, FIXED64, EXTENSION fields, and also + * callback fields. These all have integer or pointer value which + * can be compared with 0. */ pb_size_t i; const char *p = (const char*)pData; @@ -412,7 +436,7 @@ static bool checkreturn encode_extension_field(pb_ostream_t *stream, * Encode all fields * *********************/ -static void *remove_const(const void *p) +static void *const_cast(const void *p) { /* Note: this casts away const, in order to use the common field iterator * logic for both encoding and decoding. */ @@ -427,7 +451,7 @@ static void *remove_const(const void *p) bool checkreturn pb_encode(pb_ostream_t *stream, const pb_field_t fields[], const void *src_struct) { pb_field_iter_t iter; - if (!pb_field_iter_begin(&iter, fields, remove_const(src_struct))) + if (!pb_field_iter_begin(&iter, fields, const_cast(src_struct))) return true; /* Empty message type */ do { -- cgit 1.2.3-korg