ci: Get coverage working for compiled macOS code

Author: QuLogic

.github/workflows/tests.yml

@@ -285,7 +285,10 @@ jobs:
 
           # Set flag in a delayed manner to avoid issues with installing other
           # packages
-          if [[ "${{ runner.os }}" != 'macOS' ]]; then
+          if [[ "${{ runner.os }}" == 'macOS' ]]; then
+            export CPPFLAGS='-fprofile-instr-generate=default.%m.profraw'
+            export CPPFLAGS="$CPPFLAGS -fcoverage-mapping"
+          else
             export CPPFLAGS='--coverage -fprofile-abs-path'
           fi
 
@@ -310,12 +313,19 @@ jobs:
 
       - name: Filter C coverage
         run: |
-          lcov --rc lcov_branch_coverage=1 --capture --directory . --output-file coverage.info
-          lcov --rc lcov_branch_coverage=1 --output-file coverage.info \
-            --extract coverage.info $PWD/src/'*' $PWD/lib/'*'
-          lcov --rc lcov_branch_coverage=1 --list coverage.info
-          find . -name '*.gc*' -delete
-        if: ${{ runner.os != 'macOS' }}
+          if [[ "${{ runner.os }}" != 'macOS' ]]; then
+            lcov --rc lcov_branch_coverage=1 --capture --directory . \
+              --output-file coverage.info
+            lcov --rc lcov_branch_coverage=1 --output-file coverage.info \
+              --extract coverage.info $PWD/src/'*' $PWD/lib/'*'
+            lcov --rc lcov_branch_coverage=1 --list coverage.info
+            find . -name '*.gc*' -delete
+          else
+            xcrun llvm-profdata merge -sparse default.*.profraw \
+              -o default.profdata
+            xcrun llvm-cov export -format="lcov" build/*/src/*.so \
+              -instr-profile default.profdata > info.lcov
+          fi
       - name: Upload code coverage
         uses: codecov/codecov-action@v3