Change in flashrom[master]: Enable dynamic memory allocation checks for cmocka unit tests

[Anastasia Klimchuk (Code Review)]

Attention is currently required from: Nico Huber, David Hendricks, Edward O'Callaghan.
Anastasia Klimchuk has posted comments on this change. ( https://review.coreboot.org/c/flashrom/+/51243 )

Change subject: Enable dynamic memory allocation checks for cmocka unit tests
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Patch Set 4:

(2 comments)

Patchset:

PS2:
> Nico, sorry for a delay, I just needed some time to think about it. […]

Good news: I made it work! No need to include unittest_env.h in every file under test, they are now all covered. I inspected object files with nm, everything built for tests has malloc, free etc redefined, at the same time files built for real have normal memory functions.

Specifically:
nm builddir/tests/flashrom_unit_tests.p/.._flashrom.c.o
Has _test_calloc _test_free _test_malloc _test_realloc

nm builddir/flashrom.p/flashrom.c.o
Has calloc free malloc realloc

Side effect is that now running ninja test produces warnings (but seems fine, especially given this is exactly what’s happening). Example of warning (there are 4 of them)

In file included from ../tests/flashrom.c:19:
../tests/unittest.h:27: warning: "malloc" redefined
   27 | #define malloc test_malloc
      | 
In file included from <command-line>:
../unittest_env.h:46: note: this is the location of the previous definition
   46 | #define malloc(size) _test_malloc(size, __FILE__, __LINE__)

However the same approach did not work for test files :( so I am still including unittest.h into a test file, not from tests/meson.build. Which I hope is less of a problem, since this is now contained in tests/ directory.

Patchset:

PS4: 
I have the first attempt to include unittest_env.h from command line for all files under test. This solution is working, but comments are very welcome!