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Diffstat (limited to 'docs/migration.rst')
| -rw-r--r-- | docs/migration.rst | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/docs/migration.rst b/docs/migration.rst index f553d4a..4aceb95 100644 --- a/docs/migration.rst +++ b/docs/migration.rst @@ -154,6 +154,22 @@ define always has the largest value. are not defined in ascending order, user code behaviour may change. Check that user code doesn't expect the old, incorrect first/last behaviour. +Fix undefined behavior related to bool fields +--------------------------------------------- + +**Rationale:** In C99, `bool` variables are not allowed to have other values +than `true` and `false`. Compilers use this fact in optimization, and constructs +like `int foo = msg.has_field ? 100 : 0` will give unexpected results otherwise. +Previously nanopb didn't enforce that decoded bool fields had valid values. + +**Changes:** Bool fields are now handled separately as `PB_LTYPE_BOOL`. The +`LTYPE` descriptor numbers for other field types were renumbered. + +**Required actions:** Source code files must be recompiled, but regenerating +`.pb.h`/`.pb.c` files from `.proto` is not required. If user code directly uses +the nanopb internal field representation (search for `PB_LTYPE_VARINT` in source), +it may need updating. + Nanopb-0.3.9.1, 0.4.0 (2018-04-14) ================================== |