src/test/run-make-fulldeps/coverage-reports/Makefile

   1 # needs-profiler-support
   2 # ignore-windows-gnu
   3
   4 # FIXME(mati865): MinGW GCC miscompiles compiler-rt profiling library but with Clang it works
   5 # properly. Since we only have GCC on the CI ignore the test for now.
   6
   7 -include ../coverage/coverage_tools.mk
   8
   9 BASEDIR=../coverage-reports
  10 SOURCEDIR=../coverage
  11
  12 # The `llvm-cov show` flag `--debug`, used to generate the `counters` output files, is only
  13 # enabled if LLVM assertions are enabled. This requires Rust config `llvm/optimize` and not
  14 # `llvm/release_debuginfo`. Note that some CI builds disable debug assertions (by setting
  15 # `NO_LLVM_ASSERTIONS=1`), so the tests must still pass even if the `--debug` flag is
  16 # not supported. (Note that `counters` files are only produced in the `$(TMPDIR)`
  17 # directory, for inspection and debugging support. They are *not* copied to `expected_*`
  18 # files when `--bless`ed.)
  19 LLVM_COV_DEBUG := $(shell \
  20                 "$(LLVM_BIN_DIR)"/llvm-cov show --debug 2>&1 | \
  21                 grep -q "Unknown command line argument '--debug'"; \
  22                 echo $$?)
  23 ifeq ($(LLVM_COV_DEBUG), 1)
  24 DEBUG_FLAG=--debug
  25 endif
  26
  27 # FIXME(richkadel): I'm adding `--ignore-filename-regex=` line(s) for specific test(s) that produce
  28 # `llvm-cov` results for multiple files (for example `uses_crate.rs` and `used_crate/mod.rs`) as a
  29 # workaround for two problems causing tests to fail on Windows:
  30 #
  31 # 1. When multiple files appear in the `llvm-cov show` results, each file's coverage results can
  32 #    appear in different a different order. Whether this is random or, somehow, platform-specific,
  33 #    the Windows output flips the order of the files, compared to Linux. In the `uses_crate.rs`
  34 #    test, the only test-unique (interesting) results we care about are the results for only one
  35 #    of the two files, `mod/uses_crate.rs`, so the workaround is to ignore all but this one file.
  36 #    In the future, we may want a more sophisticated solution that splits apart `llvm-cov show`
  37 #    results into separate results files for each result (taking care not to create new file
  38 #    paths that might be too long for Windows MAX_PATH limits when creating these new sub-results,
  39 #    as well).
  40 # 2. When multiple files appear in the `llvm-cov show` results, the results for each file are
  41 #    prefixed with their filename, including platform-specific path separators (`\` for Windows,
  42 #    and `/` everywhere else). This could be filtered or normalized of course, but by ignoring
  43 #    coverage results for all but one of the file, the filenames are no longer included anyway.
  44 #    If this changes (if/when we decide to support `llvm-cov show` results for multiple files),
  45 #    the file path separator differences may need to be addressed.
  46 #
  47 # Since this is only a workaround, I decided to implement the override by adding an option for
  48 # each file to be ignored, using a `--ignore-filename-regex=` entry for each one, rather than
  49 # implement some more sophisticated solution with a new custom test directive in the test file
  50 # itself (similar to `expect-exit-status`) because that would add a lot of complexity and still
  51 # be a workaround, with the same result, with no benefit.
  52 #
  53 # Yes these `--ignore-filename-regex=` options are included in all invocations of `llvm-cov show`
  54 # for now, but it is effectively ignored for all tests that don't include this file anyway.
  55 #
  56 # (Note that it's also possible the `_counters.<test>.txt` and `<test>.json` files (if generated)
  57 # may order results from multiple files inconsistently, which might also have to be accomodated
  58 # if and when we allow `llvm-cov` to produce results for multiple files. Note, the path separators
  59 # appear to be normalized to `/` in those files, thankfully.)
  60 LLVM_COV_IGNORE_FILES=\
  61         --ignore-filename-regex='(uses_crate.rs|uses_inline_crate.rs)'
  62
  63 all: $(patsubst $(SOURCEDIR)/lib/%.rs,%,$(wildcard $(SOURCEDIR)/lib/*.rs)) $(patsubst $(SOURCEDIR)/%.rs,%,$(wildcard $(SOURCEDIR)/*.rs))
  64
  65 # Ensure there are no `expected` results for tests that may have been removed or renamed
  66 .PHONY: clear_expected_if_blessed
  67 clear_expected_if_blessed:
  68 ifdef RUSTC_BLESS_TEST
  69         rm -f expected_*
  70 endif
  71
  72 -include clear_expected_if_blessed
  73
  74 %: $(SOURCEDIR)/lib/%.rs
  75         # Compile the test library with coverage instrumentation
  76         $(RUSTC) $(SOURCEDIR)/lib/$@.rs \
  77                         $$( sed -n 's/^\/\/ compile-flags: \([^#]*\).*/\1/p' $(SOURCEDIR)/lib/$@.rs ) \
  78                         --crate-type rlib -Zinstrument-coverage
  79
  80 %: $(SOURCEDIR)/%.rs
  81         # Compile the test program with coverage instrumentation
  82         $(RUSTC) $(SOURCEDIR)/$@.rs \
  83                         $$( sed -n 's/^\/\/ compile-flags: \([^#]*\).*/\1/p' $(SOURCEDIR)/$@.rs ) \
  84                         -L "$(TMPDIR)" -Zinstrument-coverage
  85
  86         # Run it in order to generate some profiling data,
  87         # with `LLVM_PROFILE_FILE=<profdata_file>` environment variable set to
  88         # output the coverage stats for this run.
  89         LLVM_PROFILE_FILE="$(TMPDIR)"/$@.profraw \
  90                         $(call RUN,$@) || \
  91                         ( \
  92                                 status=$$?; \
  93                                 grep -q "^\/\/ expect-exit-status-$$status" $(SOURCEDIR)/$@.rs || \
  94                                 ( >&2 echo "program exited with an unexpected exit status: $$status"; \
  95                                         false \
  96                                 ) \
  97                         )
  98
  99         # Run it through rustdoc as well to cover doctests.
 100         # `%p` is the pid, and `%m` the binary signature. We suspect that the pid alone
 101         # might result in overwritten files and failed tests, as rustdoc spawns each
 102         # doctest as its own process, so make sure the filename is as unique as possible.
 103         LLVM_PROFILE_FILE="$(TMPDIR)"/$@-%p-%m.profraw \
 104                         $(RUSTDOC) --crate-name workaround_for_79771 --test $(SOURCEDIR)/$@.rs \
 105                         $$( sed -n 's/^\/\/ compile-flags: \([^#]*\).*/\1/p' $(SOURCEDIR)/$@.rs ) \
 106                         -L "$(TMPDIR)" -Zinstrument-coverage \
 107                         -Z unstable-options --persist-doctests=$(TMPDIR)/rustdoc-$@
 108
 109         # Postprocess the profiling data so it can be used by the llvm-cov tool
 110         "$(LLVM_BIN_DIR)"/llvm-profdata merge --sparse \
 111                         "$(TMPDIR)"/$@*.profraw \
 112                         -o "$(TMPDIR)"/$@.profdata
 113
 114         # Generate a coverage report using `llvm-cov show`.
 115         "$(LLVM_BIN_DIR)"/llvm-cov show \
 116                         $(DEBUG_FLAG) \
 117                         $(LLVM_COV_IGNORE_FILES) \
 118                         --Xdemangler="$(RUST_DEMANGLER)" \
 119                         --show-line-counts-or-regions \
 120                         --instr-profile="$(TMPDIR)"/$@.profdata \
 121                         $(call BIN,"$(TMPDIR)"/$@) \
 122                         $$( \
 123                                 for file in $(TMPDIR)/rustdoc-$@/*/rust_out; do \
 124                                 [ -x "$$file" ] && printf "%s %s " -object $$file; \
 125                                 done \
 126                         ) \
 127                 2> "$(TMPDIR)"/show_coverage_stderr.$@.txt \
 128                 | "$(PYTHON)" $(BASEDIR)/normalize_paths.py \
 129                 > "$(TMPDIR)"/actual_show_coverage.$@.txt || \
 130         ( status=$$? ; \
 131                 >&2 cat "$(TMPDIR)"/show_coverage_stderr.$@.txt ; \
 132                 exit $$status \
 133         )
 134
 135 ifdef DEBUG_FLAG
 136         # The first line (beginning with "Args:" contains hard-coded, build-specific
 137         # file paths. Strip that line and keep the remaining lines with counter debug
 138         # data.
 139         tail -n +2 "$(TMPDIR)"/show_coverage_stderr.$@.txt \
 140                 > "$(TMPDIR)"/actual_show_coverage_counters.$@.txt
 141 endif
 142
 143 ifdef RUSTC_BLESS_TEST
 144         cp "$(TMPDIR)"/actual_show_coverage.$@.txt \
 145                         expected_show_coverage.$@.txt
 146 else
 147         # Compare the show coverage output (`--bless` refreshes `typical` files).
 148         #
 149         # FIXME(richkadel): None of the Rust test source samples have the
 150         # `// ignore-llvm-cov-show-diffs` anymore. This directive exists to work around a limitation
 151         # with `llvm-cov show`. When reporting coverage for multiple instantiations of a generic function,
 152         # with different type substitutions, `llvm-cov show` prints these in a non-deterministic order,
 153         # breaking the `diff` comparision.
 154         #
 155         # A partial workaround is implemented below, with `diff --ignore-matching-lines=RE`
 156         # to ignore each line prefixing each generic instantiation coverage code region.
 157         #
 158         # This workaround only works if the coverage counts are identical across all reported
 159         # instantiations. If there is no way to ensure this, you may need to apply the
 160         # `// ignore-llvm-cov-show-diffs` directive, and check for differences using the
 161         # `.json` files to validate that results have not changed. (Until then, the JSON
 162         # files are redundant, so there is no need to generate `expected_*.json` files or
 163         # compare actual JSON results.)
 164
 165         $(DIFF) --ignore-matching-lines='^  | .*::<.*>.*:$$' --ignore-matching-lines='^  | <.*>::.*:$$' \
 166                 expected_show_coverage.$@.txt "$(TMPDIR)"/actual_show_coverage.$@.txt || \
 167                 ( grep -q '^\/\/ ignore-llvm-cov-show-diffs' $(SOURCEDIR)/$@.rs && \
 168                         >&2 echo 'diff failed, but suppressed with `// ignore-llvm-cov-show-diffs` in $(SOURCEDIR)/$@.rs' \
 169                 ) || \
 170                 ( >&2 echo 'diff failed, and not suppressed without `// ignore-llvm-cov-show-diffs` in $(SOURCEDIR)/$@.rs'; \
 171                         false \
 172                 )
 173 endif