The isc_mem_createx() function was only used in the tests to eliminate using the
default flags (which as of writing this commit message was ISC_MEMFLAG_INTERNAL
and ISC_MEMFLAG_FILL). This commit removes the isc_mem_createx() function from
the public API.
Previously isc_thread_join() would return ISC_R_UNEXPECTED on a failure to
create new thread. All such occurences were caught and wrapped into assert
function at higher level. The function was simplified to assert directly in the
isc_thread_join() function and all caller level assertions were removed.
Previously isc_thread_create() would return ISC_R_UNEXPECTED on a failure to
create new thread. All such occurences were caught and wrapped into assert
function at higher level. The function was simplified to assert directly in the
isc_thread_create() function and all caller level assertions were removed.
All unit tests define the UNIT_TESTING macro, which causes <cmocka.h> to
replace malloc(), calloc(), realloc(), and free() with its own functions
tracking memory allocations. In order for this not to break
compilation, the system header declaring the prototypes for these
standard functions must be included before <cmocka.h>.
Normally, these prototypes are only present in <stdlib.h>, so we make
sure it is included before <cmocka.h>. However, musl libc also defines
the prototypes for calloc() and free() in <sched.h>, which is included
by <pthread.h>, which is included e.g. by <isc/mutex.h>. Thus, unit
tests including "dnstest.h" (which includes <isc/mem.h>, which includes
<isc/mutex.h>) after <cmocka.h> will not compile with musl libc as for
these programs, <sched.h> will be included after <cmocka.h>.
Always including <cmocka.h> after all other header files is not a
feasible solution as that causes the mock assertion macros defined in
<isc/util.h> to mangle the contents of <cmocka.h>, thus breaking
compilation. We cannot really use the __noreturn__ or analyzer_noreturn
attributes with cmocka assertion functions because they do return if the
tested condition is true. The problem is that what BIND unit tests do
is incompatible with Clang Static Analyzer's assumptions: since we use
cmocka, our custom assertion handlers are present in a shared library
(i.e. it is the cmocka library that checks the assertion condition, not
a macro in unit test code). Redefining cmocka's assertion macros in
<isc/util.h> is an ugly hack to overcome that problem - unfortunately,
this is the only way we can think of to make Clang Static Analyzer
properly process unit test code. Giving up on Clang Static Analyzer
being able to properly process unit test code is not a satisfactory
solution.
Undefining _GNU_SOURCE for unit test code could work around the problem
(musl libc's <sched.h> only defines the prototypes for calloc() and
free() when _GNU_SOURCE is defined), but doing that could introduce
discrepancies for unit tests including entire *.c files, so it is also
not a good solution.
All in all, including <sched.h> before <cmocka.h> for all affected unit
tests seems to be the most benign way of working around this musl libc
quirk. While quite an ugly solution, it achieves our goals here, which
are to keep the benefit of proper static analysis of unit test code and
to fix compilation against musl libc.
- this enables memory to be allocated and freed in dyndb modules
when named is linked statically. when we standardize on libtool,
this should become unnecessary.
- also, simplified the isc_mem_create/createx API by removing
extra compatibility functions
Ondřej Surý
Michał Kępień
JoeyandEvan Hunt
Mark AndrewsandEvan Hunt
Tinderbox User
Mukund Sivaraman
Francis Dupont