This is configured the same as make -- a global NATIVE_COVERAGE=true
flag to allow native coverage, then COVERAGE_PATHS=path1,path2,... to
turn it on for certain paths.
There are .gcnodir files exported to Make and saved in $OUT/coverage/...
files which are `ar` archives containing all of the compiler-produced
.gcno files for a particular executable / shared library.
Unlike the Make implementation, this only passes links the helper
library (automatically through --coverage) when one of the object files
or static libraries being used actually has coverage enabled.
Host support is currently disabled, since we set -nodefaultlibs, which
prevents libclang_rt.profile-*.a from being picked up automatically.
Bug: 32749731
Test: NATIVE_COVERAGE=true COVERAGE_PATHS=system/core/libcutils m -j libbacktrace libutils tombstoned
$OUT/coverage/system/lib*/libcutils.gcnodir looks correct (self)
$OUT/coverage/system/lib*/libbacktrace.gcnodir looks correct (static)
$OUT/coverage/system/lib*/libutils.gcnodir doesn't exist (shared)
$OUT/coverage/system/bin/tombstoned.gcnodir looks correct (executable)
Test: NATIVE_COVERAGE=true COVERAGE_PATHS=external/libcxxabi m -j libc++
Confirm that $OUT/coverage/system/lib*/libc++.gcnodir looks correct (whole_static_libs)
Change-Id: I48aaa0ba8d76e50e9c2d1151421c0c6dc8ed79a9
581341d4f2