share/mk/minix.gcov.mk

   1 LCOV=lcov.$(PROG)
   2 CLEANFILES+= *.gcno *.gcda $(LCOV)
   3
   4 # Right now we support obtaining coverage information for system services only,
   5 # and for their main program code (not including their libraries) only.
   6 #
   7 # Why not userland as well: because we do not care as much, and it should be
   8 # possible to produce coverage information for system services without
   9 # recompiling the entire system with coverage support.  Moreover, as of writing
  10 # we do not have libprofile_rt, making it impossible to compile regular
  11 # programs with coverage support altogether.
  12 #
  13 # Why not system service libraries (eg libsys) as well: practical concerns..
  14 # 1) As of writing, even for such libraries we make a regular and a PIC
  15 #    version, both producing a .gcno file for each object.  The PIC version is
  16 #    compiled last, while the regular version is used for the library archive.
  17 #    The result is a potential mismatch between the compile-time coverage
  18 #    metadata and the run-time coverage counts.
  19 # 2) The kernel has no coverage support, and with its self-relocation it would
  20 #    be tricky to add support for it.  As a result, libraries used by the
  21 #    kernel would have to be excluded from being compiled with coverage support
  22 #    so as not to create problems.  One could argue that that is a good thing
  23 #    because eg libminc and libsys create too many small result units (see also
  24 #    the current hardcoded limit in libsys/llvm_gcov.c).
  25 # 3) gcov-pull(8) strips paths, which results in lots of manual work to figure
  26 #    out what file belongs to which library, even ignoring object name
  27 #    conflicts, for example between libraries.
  28 # 4) In order to produce practically useful results ("how much of libsockevent
  29 #    is covered by the combination of LWIP and UDS" etc), gcov-pull(8) would
  30 #    have to be extended with support for merging .gcda files.  The standard
  31 #    LLVM libprofile_rt implementation supports this, but we do not.
  32 # All of these issues are solvable, but for now anyone interested in coverage
  33 # for a particular system service library will have to mess with individual
  34 # makefiles themselves.
  35
  36 .if ${MKCOVERAGE:Uno} == "yes"
  37 .if ${ACTIVE_CC} == "gcc"
  38 # Leftovers for GCC.  It is not clear whether these still work at all.
  39 COVCPPFLAGS?= -fno-builtin -fprofile-arcs -ftest-coverage
  40 COVLDADD?= -lgcov
  41 .else # ${ACTIVE_CC} != "gcc"
  42 # We assume LLVM/clang here.  For other compilers this will likely break the
  43 # MKCOVERAGE compilation, which is a good indication that support for them
  44 # should be added here.
  45 COVCPPFLAGS?= --coverage -g -O0
  46 COVLDADD?=
  47 .endif # ${ACTIVE_CC} != "gcc"
  48 .endif # ${MKCOVERAGE:Uno} == "yes"
  49
  50 lcov:
  51         lcov -c -d . >$(LCOV)