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-0.3.8 (2017-xx-xx)
15 =========================
16 Fully drain substreams before closing
18 **Rationale:** If the substream functions were called directly and the caller
19 did not completely empty the substring before closing it, the parent stream
20 would be put into an incorrect state.
22 **Changes:** *pb_close_string_substream* can now error and returns a boolean.
24 **Required actions:** Add error checking onto any call to
25 *pb_close_string_substream*.
27 Nanopb-0.3.5 (2016-02-13)
28 =========================
30 Add support for platforms without uint8_t
31 -----------------------------------------
32 **Rationale:** Some platforms cannot access 8-bit sized values directly, and
33 do not define *uint8_t*. Nanopb previously didn't support these platforms.
35 **Changes:** References to *uint8_t* were replaced with several alternatives,
36 one of them being a new *pb_byte_t* typedef. This in turn uses *uint_least8_t*
37 which means the smallest available type.
39 **Required actions:** If your platform does not have a standards-compliant
40 *stdint.h*, it may lack the definition for *[u]int_least8_t*. This must be
41 added manually, example can be found in *extra/pb_syshdr.h*.
43 **Error indications:** Compiler error: "unknown type name 'uint_least8_t'".
45 Nanopb-0.3.2 (2015-01-24)
46 =========================
48 Add support for OneOfs
49 ----------------------
50 **Rationale:** Previously nanopb did not support the *oneof* construct in
51 *.proto* files. Those fields were generated as regular *optional* fields.
53 **Changes:** OneOfs are now generated as C unions. Callback fields are not
54 supported inside oneof and generator gives an error.
56 **Required actions:** The generator option *no_unions* can be used to restore old
57 behaviour and to allow callbacks to be used. To use unions, one change is
58 needed: use *which_xxxx* field to detect which field is present, instead
59 of *has_xxxx*. Compare the value against *MyStruct_myfield_tag*.
61 **Error indications:** Generator error: "Callback fields inside of oneof are
62 not supported". Compiler error: "Message" has no member named "has_xxxx".
64 Nanopb-0.3.0 (2014-08-26)
65 =========================
67 Separate field iterator logic to pb_common.c
68 --------------------------------------------
69 **Rationale:** Originally, the field iteration logic was simple enough to be
70 duplicated in *pb_decode.c* and *pb_encode.c*. New field types have made the
71 logic more complex, which required the creation of a new file to contain the
74 **Changes:** There is a new file, *pb_common.c*, which must be included in
77 **Required actions:** Add *pb_common.c* to build rules. This file is always
78 required. Either *pb_decode.c* or *pb_encode.c* can still be left out if some
79 functionality is not needed.
81 **Error indications:** Linker error: undefined reference to
82 *pb_field_iter_begin*, *pb_field_iter_next* or similar.
84 Change data type of field counts to pb_size_t
85 ---------------------------------------------
86 **Rationale:** Often nanopb is used with small arrays, such as 255 items or
87 less. Using a full *size_t* field to store the array count wastes memory if
88 there are many arrays. There already exists parameters *PB_FIELD_16BIT* and
89 *PB_FIELD_32BIT* which tell nanopb what is the maximum size of arrays in use.
91 **Changes:** Generator will now use *pb_size_t* for the array *_count* fields.
92 The size of the type will be controlled by the *PB_FIELD_16BIT* and
93 *PB_FIELD_32BIT* compilation time options.
95 **Required actions:** Regenerate all *.pb.h* files. In some cases casts to the
96 *pb_size_t* type may need to be added in the user code when accessing the
99 **Error indications:** Incorrect data at runtime, crashes. But note that other
100 changes in the same version already require regenerating the files and have
101 better indications of errors, so this is only an issue for development
104 Renamed some macros and identifiers
105 -----------------------------------
106 **Rationale:** Some names in nanopb core were badly chosen and conflicted with
107 ISO C99 reserved names or lacked a prefix. While they haven't caused trouble
108 so far, it is reasonable to switch to non-conflicting names as these are rarely
111 **Changes:** The following identifier names have changed:
115 * STATIC_ASSERT(x) -> PB_STATIC_ASSERT(x)
116 * UNUSED(x) -> PB_UNUSED(x)
120 * _PB_filename_ -> PB_filename_INCLUDED
122 * Structure forward declaration tags:
124 * _pb_field_t -> pb_field_s
125 * _pb_bytes_array_t -> pb_bytes_array_s
126 * _pb_callback_t -> pb_callback_s
127 * _pb_extension_type_t -> pb_extension_type_s
128 * _pb_extension_t -> pb_extension_s
129 * _pb_istream_t -> pb_istream_s
130 * _pb_ostream_t -> pb_ostream_s
132 **Required actions:** Regenerate all *.pb.c* files. If you use any of the above
133 identifiers in your application code, perform search-replace to the new name.
135 **Error indications:** Compiler errors on lines with the macro/type names.
137 Nanopb-0.2.9 (2014-08-09)
138 =========================
140 Change semantics of generator -e option
141 ---------------------------------------
142 **Rationale:** Some compilers do not accept filenames with two dots (like
143 in default extension .pb.c). The *-e* option to the generator allowed changing
144 the extension, but not skipping the extra dot.
146 **Changes:** The *-e* option in generator will no longer add the prepending
147 dot. The default value has been adjusted accordingly to *.pb.c* to keep the
148 default behaviour the same as before.
150 **Required actions:** Only if using the generator -e option. Add dot before
151 the parameter value on the command line.
153 **Error indications:** File not found when trying to compile generated files.
155 Nanopb-0.2.7 (2014-04-07)
156 =========================
158 Changed pointer-type bytes field datatype
159 -----------------------------------------
160 **Rationale:** In the initial pointer encoding support since nanopb-0.2.5,
161 the bytes type used a separate *pb_bytes_ptr_t* type to represent *bytes*
162 fields. This made it easy to encode data from a separate, user-allocated
163 buffer. However, it made the internal logic more complex and was inconsistent
164 with the other types.
166 **Changes:** Dynamically allocated bytes fields now have the *pb_bytes_array_t*
167 type, just like statically allocated ones.
169 **Required actions:** Only if using pointer-type fields with the bytes datatype.
170 Change any access to *msg->field.size* to *msg->field->size*. Change any
171 allocation to reserve space of amount *PB_BYTES_ARRAY_T_ALLOCSIZE(n)*. If the
172 data pointer was begin assigned from external source, implement the field using
173 a callback function instead.
175 **Error indications:** Compiler error: unknown type name *pb_bytes_ptr_t*.
177 Nanopb-0.2.4 (2013-11-07)
178 =========================
180 Remove the NANOPB_INTERNALS compilation option
181 ----------------------------------------------
182 **Rationale:** Having the option in the headers required the functions to
183 be non-static, even if the option is not used. This caused errors on some
184 static analysis tools.
186 **Changes:** The *#ifdef* and associated functions were removed from the
189 **Required actions:** Only if the *NANOPB_INTERNALS* option was previously
190 used. Actions are as listed under nanopb-0.1.3 and nanopb-0.1.6.
192 **Error indications:** Compiler warning: implicit declaration of function
193 *pb_dec_string*, *pb_enc_string*, or similar.
195 Nanopb-0.2.1 (2013-04-14)
196 =========================
198 Callback function signature
199 ---------------------------
200 **Rationale:** Previously the auxilary data to field callbacks was passed
201 as *void\**. This allowed passing of any data, but made it unnecessarily
202 complex to return a pointer from callback.
204 **Changes:** The callback function parameter was changed to *void\*\**.
206 **Required actions:** You can continue using the old callback style by
207 defining *PB_OLD_CALLBACK_STYLE*. Recommended action is to:
209 * Change the callback signatures to contain *void\*\** for decoders and
210 *void \* const \** for encoders.
211 * Change the callback function body to use *\*arg* instead of *arg*.
213 **Error indications:** Compiler warning: assignment from incompatible
214 pointer type, when initializing *funcs.encode* or *funcs.decode*.
216 Nanopb-0.2.0 (2013-03-02)
217 =========================
219 Reformatted generated .pb.c file using macros
220 ---------------------------------------------
221 **Rationale:** Previously the generator made a list of C *pb_field_t*
222 initializers in the .pb.c file. This led to a need to regenerate all .pb.c
223 files after even small changes to the *pb_field_t* definition.
225 **Changes:** Macros were added to pb.h which allow for cleaner definition
226 of the .pb.c contents. By changing the macro definitions, changes to the
227 field structure are possible without breaking compatibility with old .pb.c
230 **Required actions:** Regenerate all .pb.c files from the .proto sources.
232 **Error indications:** Compiler warning: implicit declaration of function
235 Changed pb_type_t definitions
236 -----------------------------
237 **Rationale:** The *pb_type_t* was previously an enumeration type. This
238 caused warnings on some compilers when using bitwise operations to set flags
241 **Changes:** The *pb_type_t* was changed to *typedef uint8_t*. The values
242 were changed to *#define*. Some value names were changed for consistency.
244 **Required actions:** Only if you directly access the `pb_field_t` contents
245 in your own code, something which is not usually done. Needed changes:
247 * Change *PB_HTYPE_ARRAY* to *PB_HTYPE_REPEATED*.
248 * Change *PB_HTYPE_CALLBACK* to *PB_ATYPE()* and *PB_ATYPE_CALLBACK*.
250 **Error indications:** Compiler error: *PB_HTYPE_ARRAY* or *PB_HTYPE_CALLBACK*
253 Nanopb-0.1.6 (2012-09-02)
254 =========================
256 Refactored field decoder interface
257 ----------------------------------
258 **Rationale:** Similarly to field encoders in nanopb-0.1.3.
260 **Changes:** New functions with names *pb_decode_\** were added.
262 **Required actions:** By defining NANOPB_INTERNALS, you can still keep using
263 the old functions. Recommended action is to replace any calls with the newer
264 *pb_decode_\** equivalents.
266 **Error indications:** Compiler warning: implicit declaration of function
267 *pb_dec_string*, *pb_dec_varint*, *pb_dec_submessage* or similar.
269 Nanopb-0.1.3 (2012-06-12)
270 =========================
272 Refactored field encoder interface
273 ----------------------------------
274 **Rationale:** The old *pb_enc_\** functions were designed mostly for the
275 internal use by the core. Because they are internally accessed through
276 function pointers, their signatures had to be common. This led to a confusing
277 interface for external users.
279 **Changes:** New functions with names *pb_encode_\** were added. These have
280 easier to use interfaces. The old functions are now only thin wrappers for
283 **Required actions:** By defining NANOPB_INTERNALS, you can still keep using
284 the old functions. Recommended action is to replace any calls with the newer
285 *pb_encode_\** equivalents.
287 **Error indications:** Compiler warning: implicit declaration of function
288 *pb_enc_string*, *pb_enc_varint, *pb_enc_submessage* or similar.