* rewrite int128 long divison to avoid stackoverflow hit
Protobuf was showing Stackoverflow hits in the code base, primarily code written to calculate long division. This code was copied from a stackoverflow post, which means it would be licensed under CC BY-SA 3.0. Due to this license, IBM Legal did not want to include this OSS in our products and advised us to re-write this particular piece of code to avoid the license restriction. We have re-written the code for our own distribution, and are willing to merge it into the main code base for others who want to avoid the stackoverflow license issues to benefit as well.
The problem is that sched_yield is available on the target, but configure.ac is asking to build
a host binary using the AC_SEARCH_LIBS macro. It can't configure for Android, since sched_yield isn't
available on the host.
* Adopt php_metadata_namespace in php code generator
The php_metadata_namespace is corresponded to the relative directory of
the metadata file. e.g., previously, the metadata file of foo.proto was
GPBMetadata/Foo.php. If the php_metadata_namespace is "Metadata\\Bar",
the metadata file will be Metadata/Bar/Foo.php.
* Handle empty php_metadata_namespace
Signed integer overflow creates undefined behavior that may lead to unpredictable fails on different platforms.
One known example of the hardware where this code did fail is Apple A6 (32-bit Apple Swift CPU)
16777619, 16777499 - two prime numbers that typically used to get better dispersion.
Pointer Arguments to memcpy can not be null in UndefinedBehaviorSanitizer.
In this case, both the memory and the size was zero. This change allows
protoc to run under UndefinedBehaviorSanitizer.
* Fix memory leak of exceptions raised by RaiseException()
Currently exceptions raised by RaiseException() is never deallocated because:
* ARC is disabled for this library: https://github.com/google/protobuf/blob/master/BUILD#L913
* It is constructed with `+alloc` but is never `-release`d.
This change fixes the issue by using `-[NSException exceptionWithName:...]` instead, which returns an autoreleased instance, so it is deallocated properly.
* Fix format.
With this fix, Unity using IL2CPP should work with one of two
approaches:
- Call `FileDescriptor.ForceReflectionInitialization<T>` for every
enum present in generated code (including oneof case enums)
- Ensure that IL2CPP uses the same code for int and any int-based
enums
The former approach is likely to be simpler, unless IL2CPP changes
its default behavior. We *could* potentially generate the code
automatically, but that makes me slightly uncomfortable in terms of
generating code that's only relevant in one specific scenario. It
would be reasonably easy to write a tool (separate from protoc) to
generate the code required for any specific set of assemblies, so
that Unity users can include it in their application. We can always
decide to change to generate it automatically later.