This commit adds a __wrap_memcpy function and a linker flag to use that
in place of memcpy for our Ruby gem C extension. This allows us to
always use the 2.2.5 version of memcpy, making it possible to use the
gem on distributions with pre-2.14 versions of glibc.
Before this change:
$ objdump -T protobuf_c.so | grep memcpy
0000000000000000 DF *UND* 0000000000000000 GLIBC_2.3.4 __memcpy_chk
0000000000000000 DF *UND* 0000000000000000 GLIBC_2.14 memcpy
After:
$ objdump -T protobuf_c.so | grep memcpy
0000000000000000 DF *UND* 0000000000000000 GLIBC_2.2.5 memcpy
0000000000000000 DF *UND* 0000000000000000 GLIBC_2.3.4 __memcpy_chk
0000000000042450 g DF .text 0000000000000005 Base __wrap_memcpy
This is based on gRPC's solution to a similar problem:
5098508d2d/src/core/lib/support/wrap_memcpy.c
This fixes issue #2783.
This better shows the semantic of the API. For already setted fields,
mergeFromString do replacement for singular fields and appending for
repeated fields.
- Don't prune the extension registry as that can lead to failures when two
threads are racing.
- If adding the method fails, check and see if it already is bound to decide
the return result. Deals with threading races binding the methods.
A uint32 is big enough to hold any return value from that function, and
doing it this way prevents compiler warnings in coded_stream.h about
narrowing a uint64 to a uint32.
This method merges the contents of the specified message into the
current message. Singular fields that are set in the specified message
overwrite the corresponding fields in the current message. Repeated
fields are appended. Map fields key-value pairs are overritten.
Singular/Oneof sub-messages are recursively merged. All overritten
sub-messages are deep-copied.
There are two motivations for this:
1) calcdeps.py is deprecated and replaced by closurebuilder.py.
2) As part of this I was able to tweak things so that the Closure
compiler does not attempt to examine every .js file in the tree under
js/. This makes it possible to put compatibility tests and related files
in a subdirectory without them getting mixed up with the main .js files
we care about.