Move the documentation to postgres/interface.c so it can be updated without having to update N source files.
The "is" function was not very specific so rename to "controlIs".
Rather than create _P/_PP variants for every type that needs to pass/return pointers, create FUNCTION_*_P/PP() macros that will properly pass or return any single/double pointer types.
There remain a few unresolved edge cases such as CHARPY but this handles the majority of types well.
This parameter was always useless but commit 7333b630 removed all references to it so remove the parameter at all call sites as well.
The original intention was probably to allow logging of TEST return values but that never happened.
Rename FUNCTION_DEBUG_* macros to FUNCTION_LOG_* to more accurately reflect what they do. Further rename FUNCTION_DEBUG_RESULT* macros to FUNCTION_LOG_RETURN* to make it clearer that they return from the function as well as logging. Leave FUNCTION_TEST_* macros as they are.
Consolidate the various ASSERT* macros into a single ASSERT macro that is always compiled out of production builds. It was difficult to figure out when an assert would be checked with all the different types in play. When ASSERTs are compiled in they will always be checked regardless of the log level -- tying these two concepts together was not a good idea.
PostgreSQL 11 introduces configurable WAL segment sizes, from 1MB to 1GB.
There are two areas that needed to be updated to support this: building the archive-get queue and checking that WAL has been archived after a backup. Both operations require the WAL segment size to properly build a list.
Checking the archive after a backup is still implemented in Perl and has an active database connection, so just get the WAL segment size from the database.
The archive-get command does not have a connection to the database, so get the WAL segment size from pg_control instead. This requires a deeper inspection of pg_control than has been done in the past, so it seemed best to copy the relevant data structures from each version of PostgreSQL and build a generic interface layer to address them. While this approach is a bit verbose, it has the advantage of being relatively simple, and can easily be updated for new versions of PostgreSQL.
Since the integration tests generate pg_control files for testing, teach Perl how to generate files with the correct offsets for both 32-bit and 64-bit architectures.
Use JSON code now that it is available and remove temporary hacks used to get things working initially.
Use passed storage objects rather than using storageLocal(). All storage objects in C are still local but this won't always be the case.
Also, move Postgres version conversion functions to postgres/info.c since they have no dependency on the info objects and will likely be useful elsewhere.
This is more efficient overall and allows the caller to specify how many bytes will be read on each call. Reads are appended if the buffer already contains data but the buffer size will never increase.
Allow Buffer object "used size" to be different than "allocated size". Add functions to manage used size and remaining size and update automatically when possible.
Low-level functions only include stack trace in test builds while higher-level functions ship with stack trace built-in. Stack traces include all parameters passed to the function but production builds only create the parameter list when the log level is set high enough, i.e. debug or trace depending on the function.
