python
@@ -0,0 +1,56 @@
+name: C coverage
+
+on:
+  schedule:
+    # Run this daily at 2400 UTC
+    - cron: '0 0 * * *'
+
+permissions:
+  contents: read
+
+jobs:
+  c-coverage:
+    name: 'C-level coverage (using llvm-cov)'
+    runs-on: ubuntu-20.04
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
+    env:
+      OPENSSL_VER: 1.1.1n
+      PYTHONSTRICTEXTENSIONBUILD: 1
+    steps:
+    - name: Install Dependencies
+      run: |
+        sudo ./.github/workflows/posix-deps-apt.sh
+    - name: Configure OpenSSL env vars
+      run: |
+        echo "MULTISSL_DIR=${GITHUB_WORKSPACE}/multissl" >> $GITHUB_ENV
+        echo "OPENSSL_DIR=${GITHUB_WORKSPACE}/multissl/openssl/${OPENSSL_VER}" >> $GITHUB_ENV
+        echo "LD_LIBRARY_PATH=${GITHUB_WORKSPACE}/multissl/openssl/${OPENSSL_VER}/lib" >> $GITHUB_ENV
+    - name: Restore OpenSSL build
+      id: cache-openssl
+      uses: actions/cache@v3
+      with:
+        path: ./multissl/openssl/${{ env.OPENSSL_VER }}
+        key: ${{ runner.os }}-multissl-openssl-${{ env.OPENSSL_VER }}
+    - name: Install OpenSSL
+      if: steps.cache-openssl.outputs.cache-hit != 'true'
+      run: python3 Tools/ssl/multissltests.py --steps=library --base-directory $MULTISSL_DIR --openssl $OPENSSL_VER --system Linux
+    - name: Add ccache to PATH
+      run: |
+        echo "PATH=/usr/lib/ccache:$PATH" >> $GITHUB_ENV
+    - name: Configure ccache action
+      uses: hendrikmuhs/ccache-action@v1
+    - name: Configure clang (with coverage)
+      run: |
+        echo "CC=clang" >> $GITHUB_ENV
+        echo "CXX=clang++" >> $GITHUB_ENV
+    - name: Configure CPython
+      run: ./configure --with-pydebug --with-openssl=$OPENSSL_DIR
+    - name: Generate coverage report
+      # Using "-j1" is important, or the Github Action runs out of memory
+      run: EXTRATESTOPTS=-j1 xvfb-run make coverage-report
+    - name: Publish coverage-report
+      uses: JamesIves/github-pages-deploy-action@v4
+      with:
+        folder: coverage-report
+        repository-name: '' # TODO Destination
+        token: ${{ secrets.COVERAGE_DEPLOY_TOKEN }} # TODO: Use an organization-level token
+        single-commit: true
diff --git a/.gitignore b/.gitignore
@@ -23,6 +23,7 @@
 *.gc??
 *.profclang?
 *.profraw
+*.profdata
 *.dyn
 .gdb_history
 .purify

@@ -797,9 +797,11 @@ def is_env_var_to_ignore(n):
             # This excludes some __CF_* and VERSIONER_* keys MacOS insists
             # on adding even when the environment in exec is empty.
             # Gentoo sandboxes also force LD_PRELOAD and SANDBOX_* to exist.
+            # LLVM coverage adds __LLVM_PROFILE_RT_INIT_ONCE variable.
             return ('VERSIONER' in n or '__CF' in n or  # MacOS
                     n == 'LD_PRELOAD' or n.startswith('SANDBOX') or # Gentoo
-                    n == 'LC_CTYPE') # Locale coercion triggered
+                    n == 'LC_CTYPE' or # Locale coercion triggered
+                    n == '__LLVM_PROFILE_RT_INIT_ONCE')
 
         with subprocess.Popen([sys.executable, "-c",
                                'import os; print(list(os.environ.keys()))'],

@@ -50,6 +50,8 @@ PGO_PROF_USE_FLAG=@PGO_PROF_USE_FLAG@
 LLVM_PROF_MERGER=@LLVM_PROF_MERGER@
 LLVM_PROF_FILE=@LLVM_PROF_FILE@
 LLVM_PROF_ERR=@LLVM_PROF_ERR@
+LLVM_PROFDATA=@LLVM_PROFDATA@
+LLVM_COV=@LLVM_COV@
 DTRACE=         @DTRACE@
 DFLAGS=         @DFLAGS@
 DTRACE_HEADERS= @DTRACE_HEADERS@
@@ -310,12 +312,15 @@ HOST_GNU_TYPE=	@host@
 # PROFILE_TASK="-m test --pgo-extended"
 PROFILE_TASK=	@PROFILE_TASK@
 
-# report files for gcov / lcov coverage report
-COVERAGE_INFO=	$(abs_builddir)/coverage.info
-COVERAGE_REPORT=$(abs_builddir)/lcov-report
-COVERAGE_LCOV_OPTIONS=--rc lcov_branch_coverage=1
-COVERAGE_REPORT_OPTIONS=--rc lcov_branch_coverage=1 --branch-coverage --title "CPython $(VERSION) LCOV report [commit $(shell $(GITVERSION))]"
-
+# parameters for coverage
+COVERAGE_CC=@COVERAGE_CC@
+COVERAGE_CFLAGS=@COVERAGE_CFLAGS@
+COVERAGE_LDFLAGS=@COVERAGE_LDFLAGS@
+COVERAGE_GEN_TARGET=@COVERAGE_GEN_TARGET@
+COVERAGE_INFO=$(abs_builddir)/@COVERAGE_INFO@
+COVERAGE_REPORT=$(abs_builddir)/coverage-report
+COVERAGE_OPTIONS=@COVERAGE_OPTIONS@
+COVERAGE_REPORT_OPTIONS=@COVERAGE_REPORT_OPTIONS@
 
 # === Definitions added by makesetup ===
 
@@ -655,25 +660,41 @@ bolt-opt: @PREBOLT_RULE@
 	rm -f $(BUILDPYTHON).bolt_inst
 	mv $(BUILDPYTHON).bolt $(BUILDPYTHON)
 
-# Compile and run with gcov
-.PHONY=coverage coverage-lcov coverage-report
+# Support generating coverage reports
+.PHONY=coverage-report coverage coverage-generate-lcov coverage-generate-profdata
+coverage-report: regen-token regen-frozen
+	@ # build with coverage info
+	$(MAKE) coverage
+	@ # run tests, ignore failures
+	@ # The LLVM_PROFILE_FILE must specify %m so results can be collected in parallel.
+	@ # Also, must be an absolute path since test suite changes working directory.
+	LLVM_PROFILE_FILE=${abs_builddir}/python%m.profraw $(TESTRUNNER) $(TESTOPTS) || true
+	@ # build lcov report
+	$(MAKE) $(COVERAGE_GEN_TARGET)
+	@echo
+	@echo "coverage report at $(COVERAGE_REPORT)/index.html"
+	@echo
+
+# Compile and run generating coverage
 coverage:
 	@echo "Building with support for coverage checking:"
 	$(MAKE) clean
-	$(MAKE) @DEF_MAKE_RULE@ CFLAGS="$(CFLAGS) -O0 -pg --coverage" LDFLAGS="$(LDFLAGS) --coverage"
+	$(MAKE) @DEF_MAKE_RULE@ CC="$(COVERAGE_CC)" \
+		CFLAGS="$(CFLAGS) $(COVERAGE_CFLAGS)" \
+		LDFLAGS="$(LDFLAGS) $(COVERAGE_LDFLAGS)"
 
-coverage-lcov:
+coverage-generate-lcov:
 	@echo "Creating Coverage HTML report with LCOV:"
 	@rm -f $(COVERAGE_INFO)
 	@rm -rf $(COVERAGE_REPORT)
-	@lcov $(COVERAGE_LCOV_OPTIONS) --capture \
+	@lcov $(COVERAGE_OPTIONS) --capture \
 	    --directory $(abs_builddir) \
 	    --base-directory $(realpath $(abs_builddir)) \
 	    --path $(realpath $(abs_srcdir)) \
 	    --output-file $(COVERAGE_INFO)
 	@ # remove 3rd party modules, system headers and internal files with
 	@ # debug, test or dummy functions.
-	@lcov $(COVERAGE_LCOV_OPTIONS) --remove $(COVERAGE_INFO) \
+	@lcov $(COVERAGE_OPTIONS) --remove $(COVERAGE_INFO) \
 	    '*/Modules/_blake2/impl/*' \
 	    '*/Modules/_ctypes/libffi*/*' \
 	    '*/Modules/_decimal/libmpdec/*' \
@@ -688,18 +709,15 @@ coverage-lcov:
 	@genhtml $(COVERAGE_INFO) \
 	    --output-directory $(COVERAGE_REPORT) \
 	    $(COVERAGE_REPORT_OPTIONS)
-	@echo
-	@echo "lcov report at $(COVERAGE_REPORT)/index.html"
-	@echo
 
-# Force regeneration of parser and frozen modules
-coverage-report: regen-token regen-frozen
-	@ # build with coverage info
-	$(MAKE) coverage
-	@ # run tests, ignore failures
-	$(TESTRUNNER) $(TESTOPTS) || true
-	@ # build lcov report
-	$(MAKE) coverage-lcov
+coverage-generate-profdata:
+	@echo "Creating Coverage HTML report with llvm-profdata/llvm-cov:"
+	@rm -f $(COVERAGE_INFO)
+	@rm -rf $(COVERAGE_REPORT)
+	@ # Merge coverage results
+	$(LLVM_PROFDATA) merge -sparse python*.profraw -o $(COVERAGE_INFO)
+	@ # Generate HTML
+	$(LLVM_COV) show -format=html -output-dir=$(COVERAGE_REPORT) -instr-profile=$(COVERAGE_INFO) $(COVERAGE_REPORT_OPTIONS) python .
 
 # Run "Argument Clinic" over all source files
 .PHONY=clinic

diff --git a/Misc/NEWS.d/next/Build/2022-07-13-13-24-01.gh-issue-94759.dTLMod.rst b/Misc/NEWS.d/next/Build/2022-07-13-13-24-01.gh-issue-94759.dTLMod.rst
@@ -0,0 +1 @@
+The ``coverage-report`` Makefile now supports both the ``gcc/lcov`` and ``clang/llvm-profdata`` stacks to generate coverage reports, and will select the correct one based on the compiler in use.
@@ -2056,6 +2056,40 @@ case $CC in
     ;;
 esac
 
+# Coverage flags
+
+case $CC in
+     *clang*)
+         COVERAGE_CC="\$(CC) -fprofile-instr-generate -fcoverage-mapping"
+         COVERAGE_CFLAGS=""
+         COVERAGE_LDFLAGS=""
+         COVERAGE_GEN_TARGET="coverage-generate-profdata"
+         COVERAGE_INFO="coverage.profdata"
+         COVERAGE_OPTIONS=""
+         COVERAGE_REPORT_OPTIONS="-show-branches=count -show-regions"
+         ;;
+     *gcc*)
+         COVERAGE_CC="\$(CC)"
+         COVERAGE_CFLAGS="-O0 -pg --coverage"
+         COVERAGE_LDFLAGS="--coverage"
+         COVERAGE_GEN_TARGET="coverage-generate-lcov"
+         COVERAGE_INFO="coverage.info"
+         COVERAGE_OPTIONS="--rc lcov_brange_coverage=1"
+         COVERAGE_REPORT_OPTIONS="\$(COVERAGE_OPTIONS) --branch-coverage --title \"CPython \$(VERSION) LCOV report [commit \$(shell \$(GITVERSION))]\""
+         ;;
+     *)
+esac
+
+AC_SUBST(COVERAGE_CC)
+AC_SUBST(COVERAGE_CFLAGS)
+AC_SUBST(COVERAGE_LDFLAGS)
+AC_SUBST(COVERAGE_GEN_TARGET)
+AC_SUBST(COVERAGE_INFO)
+AC_SUBST(COVERAGE_OPTIONS)
+AC_SUBST(COVERAGE_REPORT_OPTIONS)
+AC_SUBST(LLVM_COV)
+AC_PATH_TOOL(LLVM_COV, llvm-cov, '', ${llvm_path})
+
 # XXX Shouldn't the code above that fiddles with BASECFLAGS and OPT be
 # merged with this chunk of code?
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1 @@
		The ``coverage-report`` Makefile now supports both the ``gcc/lcov`` and ``clang/llvm-profdata`` stacks to generate coverage reports, and will select the correct one based on the compiler in use.