This commit resolves issue #620:
Remove CONFIG_CAN_PASS_STRUCTS #620
The configuration option CONFIG_CAN_PASS_STRUCTS was added many years ago to support an old version of the SDCC compiler. That compiler is currently used only with the Z80 and Z180 targets. The limitation of that old compiler was that it could not pass structures or unions as either inputs or outputs. For example:
#ifdef CONFIG_CAN_PASS_STRUCTS
struct mallinfo mallinfo(void);
#else
int mallinfo(FAR struct mallinfo *info);
#endif
And even leads to violation of a few POSIX interfaces like:
#ifdef CONFIG_CAN_PASS_STRUCTS
int sigqueue(int pid, int signo, union sigval value);
#else
int sigqueue(int pid, int signo, FAR void *sival_ptr);
#endif
This breaks the 1st INVIOLABLES rule:
Strict POSIX compliance
-----------------------
o Strict conformance to the portable standard OS interface as defined at
OpenGroup.org.
o A deeply embedded system requires some special support. Special
support must be minimized.
o The portable interface must never be compromised only for the sake of
expediency.
o Expediency or even improved performance are not justifications for
violation of the strict POSIX interface
Also, it appears that the current SDCC compilers have resolve this issue and so, perhaps, this is no longer a problem: z88dk/z88dk#1132
NOTE: This commit cannot pass the PR checks because it depends on matching changes to the apps/ directory.
The solution is to remove all of the memory management function calls from the interface. Instead, the interface exports the userspace heap structure and then kernel size implementations of those memory management functions will operate on the userspace heap structure. This avoids the unnecessary system calls and, more importantly, failures do to freeing memory when a test exits.
