On Tue, Oct 15, 2019 at 11:01 PM Andrii Nakryiko <andriin@xxxxxx> wrote: > > Define test runner generation meta-rule that codifies dependencies > between test runner, its tests, and its dependent BPF programs. Use that > for defining test_progs and test_maps test-runners. Also additionally define > 2 flavors of test_progs: > - alu32, which builds BPF programs with 32-bit registers codegen; > - bpf_gcc, which build BPF programs using GCC, if it supports BPF target. > > Overall, this is accomplished through $(eval)'ing a set of generic > rules, which defines Makefile targets dynamically at runtime. See > comments explaining the need for 2 $(evals), though. > > For each test runner we have (test_maps and test_progs, currently), and, > optionally, their flavors, the logic of build process is modeled as > follows (using test_progs as an example): > - all BPF objects are in progs/: > - BPF object's .o file is built into output directory from > corresponding progs/.c file; > - all BPF objects in progs/*.c depend on all progs/*.h headers; > - all BPF objects depend on bpf_*.h helpers from libbpf (but not > libbpf archive). There is an extra rule to trigger bpf_helper_defs.h > (re-)build, if it's not present/outdated); > - build recipe for BPF object can be re-defined per test runner/flavor; > - test files are built from prog_tests/*.c: > - all such test file objects are built on individual file basis; > - currently, every single test file depends on all BPF object files; > this might be improved in follow up patches to do 1-to-1 dependency, > but allowing to customize this per each individual test; > - each test runner definition can specify a list of extra .c and .h > files to be built along test files and test runner binary; all such > headers are becoming automatic dependency of each test .c file; > - due to test files sometimes embedding (using .incbin assembly > directive) contents of some BPF objects at compilation time, which are > expected to be in CWD of compiler, compilation for test file object does > cd into test runner's output directory; to support this mode all the > include paths are turned into absolute paths using $(abspath) make > function; > - prog_tests/test.h is automatically (re-)generated with an entry for > each .c file in prog_tests/; > - final test runner binary is linked together from test object files and > extra object files, linking together libbpf's archive as well; > - it's possible to specify extra "resource" files/targets, which will be > copied into test runner output directory, if it differes from > Makefile-wide $(OUTPUT). This is used to ensure btf_dump test cases and > urandom_read binary is put into a test runner's CWD for tests to find > them in runtime. > > For flavored test runners, their output directory is a subdirectory of > common Makefile-wide $(OUTPUT) directory with flavor name used as > subdirectory name. > > BPF objects targets might be reused between different test runners, so > extra checks are employed to not double-define them. Similarly, we have > redefinition guards for output directories and test headers. > > test_verifier follows slightly different patterns and is simple enough > to not justify generalizing TEST_RUNNER_DEFINE/TEST_RUNNER_DEFINE_RULES > further to accomodate these differences. Instead, rules for > test_verifier are minimized and simplified, while preserving correctness > of dependencies. > > Signed-off-by: Andrii Nakryiko <andriin@xxxxxx> > --- BTW, if correctness and DRY-ness argument is not strong enough, these changes makes clean rebuild from scratch about 2x faster for me: BEFORE: `make clean && time make -j50` is 14-15 seconds AFTER: `make clean && time make -j50` is 7-8 seconds [...]
