The primary benefit is that objects can allocate memory for their struct with the context, which saves an additional allocation and makes it easier to read context/allocation dumps. Also, the memory context does not need to be stored with the object since it can be determined using the object pointer.
Object pointers cannot be moved, so this means whatever additional memory is allocated cannot be resized. That makes the additional memory ideal for object structs, but not so much for allocating a list that might change size.
Mem contexts can no longer be reused since they will probably be the wrong size so their memory is freed on memContextFree(). This still means fewer allocations and frees overall.
Interfaces still need to be freed by mem context so the old objMove() and objFree() have been preserved as objMoveContext() and objFreeContext(). This will be addressed in a future commit.
This has been the policy for some time but due to migration pressure only new functions and refactors have been following this rule. Now it seems sensible to make a clean sweep and move all the comments that have not been moved already (i.e. most of them).
Only obvious typos and gross inaccuracies in the comments have been fixed. For this most part this was a copy and paste operation.
Useless comments, e.g. "New object", were not copied. Even so, there are surely many deficient comments left.
Some rearranging was done where needed and functions were placed in the proper sections, e.g. "Constructors", "Functions", etc.
A few function prototypes were found that not longer had an implementation. These were removed, but there may be more.
The coding document has been updated to reflect this policy, which is not new but has never been documented.
Previously memNew() used memset() to initialize all struct members to 0, NULL, false, etc. While this appears to work in practice, it is a violation of the C specification. For instance, NULL == 0 must be true but neither NULL nor 0 must be represented with all zero bits.
Instead use designated initializers to initialize structs. These guarantee that struct members will be properly initialized even if they are not specified in the initializer. Note that due to a quirk in the C99 specification at least one member must be explicitly initialized even if it needs to be the default value.
Since pre-zeroed memory is no longer required, adjust memAllocInternal()/memReallocInternal() to return raw memory and update dependent functions accordingly. All instances of memset() have been removed except in debug/test code where needed.
Add memMewPtrArray() to allocate an array of pointers and automatically set all pointers to NULL.
Rename memGrowRaw() to the more logical memResize().
The function pointer casting used when creating drivers made changing interfaces difficult and led to slightly divergent driver implementations. Unit testing caught production-level errors but there were a lot of small issues and the process was harder than it should have been.
Use void pointers instead so that no casts are required. Introduce the THIS_VOID and THIS() macros to make dealing with void pointers a little safer.
Since we don't want to expose void pointers in header files, driver functions have been removed from the headers and the various driver objects return their interface type. This cuts down on accessor methods and the vast majority of those functions were not being used. Move functions that are still required to .intern.h.
Remove the special "C" crypto functions that were used in libc and instead use the standard interface.
Use autoconf to provide a basic configure script. WITH_BACKTRACE is yet to be migrated to configure and the unit tests still use a custom Makefile.
Each C file must include "build.auto.conf" before all other includes and defines. This is enforced by test.pl for includes, but it won't detect incorrect define ordering.
Update packages to call configure and use standard flags to pass options.
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.
Fixed parameter constructors made adding new interface functions a burden, so we switched to using structs to define interfaces in the storage module at c49eaec7.
While propagating this pattern to the IO interfaces it became obvious that the existing variable parameter function pattern (begun in the storage module) was more succinct and consistent with the existing code.
So, use variable parameter functions to define all interfaces. This assumes that the non-interface parameters will be fixed, which seems reasonable for low-level code.
