1 =====================================
2 Nanopb: Migration from older versions
3 =====================================
7 This document details all the breaking changes that have been made to nanopb
8 since its initial release. For each change, the rationale and required
9 modifications of user applications are explained. Also any error indications
10 are included, in order to make it easier to find this document.
14 Nanopb-0.3.5 (2016-xx-xx)
15 =========================
17 Add support for platforms without uint8_t
18 -----------------------------------------
19 **Rationale:** Some platforms cannot access 8-bit sized values directly, and
20 do not define *uint8_t*. Nanopb previously didn't support these platforms.
22 **Changes:** References to *uint8_t* were replaced with several alternatives,
23 one of them being a new *pb_byte_t* typedef. This in turn uses *uint_least8_t*
24 which means the smallest available type.
26 **Required actions:** If your platform does not have a standards-compliant
27 *stdint.h*, it may lack the definition for *[u]int_least8_t*. This must be
28 added manually, example can be found in *extra/pb_syshdr.h*.
30 **Error indications:** Compiler error: "unknown type name 'uint_least8_t'".
32 Nanopb-0.3.2 (2015-01-24)
33 =========================
35 Add support for OneOfs
36 ----------------------
37 **Rationale:** Previously nanopb did not support the *oneof* construct in
38 *.proto* files. Those fields were generated as regular *optional* fields.
40 **Changes:** OneOfs are now generated as C unions. Callback fields are not
41 supported inside oneof and generator gives an error.
43 **Required actions:** The generator option *no_unions* can be used to restore old
44 behaviour and to allow callbacks to be used. To use unions, one change is
45 needed: use *which_xxxx* field to detect which field is present, instead
46 of *has_xxxx*. Compare the value against *MyStruct_myfield_tag*.
48 **Error indications:** Generator error: "Callback fields inside of oneof are
49 not supported". Compiler error: "Message" has no member named "has_xxxx".
51 Nanopb-0.3.0 (2014-08-26)
52 =========================
54 Separate field iterator logic to pb_common.c
55 --------------------------------------------
56 **Rationale:** Originally, the field iteration logic was simple enough to be
57 duplicated in *pb_decode.c* and *pb_encode.c*. New field types have made the
58 logic more complex, which required the creation of a new file to contain the
61 **Changes:** There is a new file, *pb_common.c*, which must be included in
64 **Required actions:** Add *pb_common.c* to build rules. This file is always
65 required. Either *pb_decode.c* or *pb_encode.c* can still be left out if some
66 functionality is not needed.
68 **Error indications:** Linker error: undefined reference to
69 *pb_field_iter_begin*, *pb_field_iter_next* or similar.
71 Change data type of field counts to pb_size_t
72 ---------------------------------------------
73 **Rationale:** Often nanopb is used with small arrays, such as 255 items or
74 less. Using a full *size_t* field to store the array count wastes memory if
75 there are many arrays. There already exists parameters *PB_FIELD_16BIT* and
76 *PB_FIELD_32BIT* which tell nanopb what is the maximum size of arrays in use.
78 **Changes:** Generator will now use *pb_size_t* for the array *_count* fields.
79 The size of the type will be controlled by the *PB_FIELD_16BIT* and
80 *PB_FIELD_32BIT* compilation time options.
82 **Required actions:** Regenerate all *.pb.h* files. In some cases casts to the
83 *pb_size_t* type may need to be added in the user code when accessing the
86 **Error indications:** Incorrect data at runtime, crashes. But note that other
87 changes in the same version already require regenerating the files and have
88 better indications of errors, so this is only an issue for development
91 Renamed some macros and identifiers
92 -----------------------------------
93 **Rationale:** Some names in nanopb core were badly chosen and conflicted with
94 ISO C99 reserved names or lacked a prefix. While they haven't caused trouble
95 so far, it is reasonable to switch to non-conflicting names as these are rarely
98 **Changes:** The following identifier names have changed:
102 * STATIC_ASSERT(x) -> PB_STATIC_ASSERT(x)
103 * UNUSED(x) -> PB_UNUSED(x)
107 * _PB_filename_ -> PB_filename_INCLUDED
109 * Structure forward declaration tags:
111 * _pb_field_t -> pb_field_s
112 * _pb_bytes_array_t -> pb_bytes_array_s
113 * _pb_callback_t -> pb_callback_s
114 * _pb_extension_type_t -> pb_extension_type_s
115 * _pb_extension_t -> pb_extension_s
116 * _pb_istream_t -> pb_istream_s
117 * _pb_ostream_t -> pb_ostream_s
119 **Required actions:** Regenerate all *.pb.c* files. If you use any of the above
120 identifiers in your application code, perform search-replace to the new name.
122 **Error indications:** Compiler errors on lines with the macro/type names.
124 Nanopb-0.2.9 (2014-08-09)
125 =========================
127 Change semantics of generator -e option
128 ---------------------------------------
129 **Rationale:** Some compilers do not accept filenames with two dots (like
130 in default extension .pb.c). The *-e* option to the generator allowed changing
131 the extension, but not skipping the extra dot.
133 **Changes:** The *-e* option in generator will no longer add the prepending
134 dot. The default value has been adjusted accordingly to *.pb.c* to keep the
135 default behaviour the same as before.
137 **Required actions:** Only if using the generator -e option. Add dot before
138 the parameter value on the command line.
140 **Error indications:** File not found when trying to compile generated files.
142 Nanopb-0.2.7 (2014-04-07)
143 =========================
145 Changed pointer-type bytes field datatype
146 -----------------------------------------
147 **Rationale:** In the initial pointer encoding support since nanopb-0.2.5,
148 the bytes type used a separate *pb_bytes_ptr_t* type to represent *bytes*
149 fields. This made it easy to encode data from a separate, user-allocated
150 buffer. However, it made the internal logic more complex and was inconsistent
151 with the other types.
153 **Changes:** Dynamically allocated bytes fields now have the *pb_bytes_array_t*
154 type, just like statically allocated ones.
156 **Required actions:** Only if using pointer-type fields with the bytes datatype.
157 Change any access to *msg->field.size* to *msg->field->size*. Change any
158 allocation to reserve space of amount *PB_BYTES_ARRAY_T_ALLOCSIZE(n)*. If the
159 data pointer was begin assigned from external source, implement the field using
160 a callback function instead.
162 **Error indications:** Compiler error: unknown type name *pb_bytes_ptr_t*.
164 Nanopb-0.2.4 (2013-11-07)
165 =========================
167 Remove the NANOPB_INTERNALS compilation option
168 ----------------------------------------------
169 **Rationale:** Having the option in the headers required the functions to
170 be non-static, even if the option is not used. This caused errors on some
171 static analysis tools.
173 **Changes:** The *#ifdef* and associated functions were removed from the
176 **Required actions:** Only if the *NANOPB_INTERNALS* option was previously
177 used. Actions are as listed under nanopb-0.1.3 and nanopb-0.1.6.
179 **Error indications:** Compiler warning: implicit declaration of function
180 *pb_dec_string*, *pb_enc_string*, or similar.
182 Nanopb-0.2.1 (2013-04-14)
183 =========================
185 Callback function signature
186 ---------------------------
187 **Rationale:** Previously the auxilary data to field callbacks was passed
188 as *void\**. This allowed passing of any data, but made it unnecessarily
189 complex to return a pointer from callback.
191 **Changes:** The callback function parameter was changed to *void\*\**.
193 **Required actions:** You can continue using the old callback style by
194 defining *PB_OLD_CALLBACK_STYLE*. Recommended action is to:
196 * Change the callback signatures to contain *void\*\** for decoders and
197 *void \* const \** for encoders.
198 * Change the callback function body to use *\*arg* instead of *arg*.
200 **Error indications:** Compiler warning: assignment from incompatible
201 pointer type, when initializing *funcs.encode* or *funcs.decode*.
203 Nanopb-0.2.0 (2013-03-02)
204 =========================
206 Reformatted generated .pb.c file using macros
207 ---------------------------------------------
208 **Rationale:** Previously the generator made a list of C *pb_field_t*
209 initializers in the .pb.c file. This led to a need to regenerate all .pb.c
210 files after even small changes to the *pb_field_t* definition.
212 **Changes:** Macros were added to pb.h which allow for cleaner definition
213 of the .pb.c contents. By changing the macro definitions, changes to the
214 field structure are possible without breaking compatibility with old .pb.c
217 **Required actions:** Regenerate all .pb.c files from the .proto sources.
219 **Error indications:** Compiler warning: implicit declaration of function
222 Changed pb_type_t definitions
223 -----------------------------
224 **Rationale:** The *pb_type_t* was previously an enumeration type. This
225 caused warnings on some compilers when using bitwise operations to set flags
228 **Changes:** The *pb_type_t* was changed to *typedef uint8_t*. The values
229 were changed to *#define*. Some value names were changed for consistency.
231 **Required actions:** Only if you directly access the `pb_field_t` contents
232 in your own code, something which is not usually done. Needed changes:
234 * Change *PB_HTYPE_ARRAY* to *PB_HTYPE_REPEATED*.
235 * Change *PB_HTYPE_CALLBACK* to *PB_ATYPE()* and *PB_ATYPE_CALLBACK*.
237 **Error indications:** Compiler error: *PB_HTYPE_ARRAY* or *PB_HTYPE_CALLBACK*
240 Nanopb-0.1.6 (2012-09-02)
241 =========================
243 Refactored field decoder interface
244 ----------------------------------
245 **Rationale:** Similarly to field encoders in nanopb-0.1.3.
247 **Changes:** New functions with names *pb_decode_\** were added.
249 **Required actions:** By defining NANOPB_INTERNALS, you can still keep using
250 the old functions. Recommended action is to replace any calls with the newer
251 *pb_decode_\** equivalents.
253 **Error indications:** Compiler warning: implicit declaration of function
254 *pb_dec_string*, *pb_dec_varint*, *pb_dec_submessage* or similar.
256 Nanopb-0.1.3 (2012-06-12)
257 =========================
259 Refactored field encoder interface
260 ----------------------------------
261 **Rationale:** The old *pb_enc_\** functions were designed mostly for the
262 internal use by the core. Because they are internally accessed through
263 function pointers, their signatures had to be common. This led to a confusing
264 interface for external users.
266 **Changes:** New functions with names *pb_encode_\** were added. These have
267 easier to use interfaces. The old functions are now only thin wrappers for
270 **Required actions:** By defining NANOPB_INTERNALS, you can still keep using
271 the old functions. Recommended action is to replace any calls with the newer
272 *pb_encode_\** equivalents.
274 **Error indications:** Compiler warning: implicit declaration of function
275 *pb_enc_string*, *pb_enc_varint, *pb_enc_submessage* or similar.