Collect Clang coverage for native host tests.

Host GTests will collect Clang coverage measurements when coverage is
enabled.

Bug: 278116048
Test: atest adb_test --experimental-coverage
Test: atest liblog-host-test --experimental-coverage
Test: unit tests
Change-Id: Iee5dfd48bb77a1aee1e7a5badf7232301e9924fb

5 files changed, 315 insertions, 55 deletions

diff --git a/javatests/com/android/tradefed/UnitTests.java b/javatests/com/android/tradefed/UnitTests.java
index 9abdf4a06..0ea56e08f 100644
--- a/javatests/com/android/tradefed/UnitTests.java
+++ b/javatests/com/android/tradefed/UnitTests.java
@@ -412,6 +412,7 @@ import com.android.tradefed.util.BugreportTest;
 import com.android.tradefed.util.BuildTestsZipUtilsTest;
 import com.android.tradefed.util.BundletoolUtilTest;
 import com.android.tradefed.util.ByteArrayListTest;
+import com.android.tradefed.util.ClangProfileIndexerTest;
 import com.android.tradefed.util.ClassPathScannerTest;
 import com.android.tradefed.util.ConditionPriorityBlockingQueueTest;
 import com.android.tradefed.util.DeviceActionUtilTest;
@@ -1017,6 +1018,7 @@ import org.junit.runners.Suite.SuiteClasses;
     BundletoolUtilTest.class,
     ByteArrayListTest.class,
     CentralDirectoryInfoTest.class,
+    ClangProfileIndexerTest.class,
     ClassPathScannerTest.class,
     ConditionPriorityBlockingQueueTest.class,
     DeviceActionUtilTest.class,
diff --git a/javatests/com/android/tradefed/util/ClangProfileIndexerTest.java b/javatests/com/android/tradefed/util/ClangProfileIndexerTest.java
new file mode 100644
index 000000000..422b1250a
--- /dev/null
+++ b/javatests/com/android/tradefed/util/ClangProfileIndexerTest.java
@@ -0,0 +1,171 @@
+/*
+ * Copyright (C) 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.tradefed.util;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import static org.junit.Assert.fail;
+
+import com.google.common.collect.ImmutableList;
+
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.TemporaryFolder;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+import org.mockito.MockitoAnnotations;
+import org.mockito.Spy;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.ArrayDeque;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Queue;
+
+/** Unit tests for {@link ClangProfileIndexer}. */
+@RunWith(JUnit4.class)
+public class ClangProfileIndexerTest {
+    private static final int MAX_PROFILE_FILES = 100;
+
+    @Rule public TemporaryFolder folder = new TemporaryFolder();
+    @Spy CommandArgumentCaptor mCommandArgumentCaptor;
+
+    /** Object under test. */
+    ClangProfileIndexer mIndexer;
+
+    @Before
+    public void setUp() throws Exception {
+        MockitoAnnotations.initMocks(this);
+
+        mIndexer = new ClangProfileIndexer(new File("/path/to/llvm-tools"), mCommandArgumentCaptor);
+    }
+
+    @Test
+    public void testProfileFiles_includesFiles() throws Exception {
+        mCommandArgumentCaptor.setResult(CommandStatus.SUCCESS);
+        List<String> profileFiles =
+                ImmutableList.of("/path/to/clang-1.profraw", "/path/to/clang-2.profraw");
+        File outputFile = folder.newFile();
+
+        mIndexer.index(profileFiles, outputFile);
+
+        List<String> command = mCommandArgumentCaptor.getCommand();
+
+        // Check contents of the command line contain what we expect.
+        assertThat(command)
+                .containsAtLeast(
+                        "/path/to/llvm-tools/bin/llvm-profdata",
+                        "merge",
+                        outputFile.getAbsolutePath());
+        assertThat(command).containsAtLeastElementsIn(profileFiles);
+    }
+
+    @Test
+    public void testLargeProfileCount_usesFile() throws Exception {
+        mCommandArgumentCaptor.setResult(CommandStatus.SUCCESS);
+        List<String> profileFiles = new ArrayList<>(MAX_PROFILE_FILES + 5);
+        for (int i = 0; i < MAX_PROFILE_FILES + 5; i++) {
+            profileFiles.add(String.format("path/to/clang-%d.profraw", i));
+        }
+
+        mIndexer.index(profileFiles, folder.newFile());
+        List<String> command = mCommandArgumentCaptor.getCommand();
+
+        // Contains the `-f` argument that points to a file containing the list of profile files.
+        assertThat(command.size()).isLessThan(MAX_PROFILE_FILES);
+        assertThat(command).contains("-f");
+        checkListDoesNotContainSuffix(command, ".profraw");
+    }
+
+    @Test
+    public void testSingleFailure_usesFailureMode() throws Exception {
+        mCommandArgumentCaptor.setResult(CommandStatus.FAILED).setResult(CommandStatus.SUCCESS);
+        List<String> profileFiles =
+                ImmutableList.of("/path/to/clang-1.profraw", "/path/to/clang-2.profraw");
+
+        mIndexer.index(profileFiles, folder.newFile());
+
+        List<String> command = mCommandArgumentCaptor.getCommand();
+        assertThat(command).contains("-failure-mode=all");
+    }
+
+    @Test
+    public void testMultipleFailures_throwsException() throws Exception {
+        mCommandArgumentCaptor.setResult(CommandStatus.FAILED).setResult(CommandStatus.FAILED);
+        List<String> profileFiles = ImmutableList.of("/path/to/clang-1.profraw");
+
+        try {
+            mIndexer.index(profileFiles, folder.newFile());
+            fail("should have thrown an exception");
+        } catch (IOException e) {
+            // Expected
+        }
+    }
+
+    abstract static class CommandArgumentCaptor implements IRunUtil {
+        private List<String> mCommand = new ArrayList<>();
+        private Queue<CommandStatus> mResults = new ArrayDeque<>();
+
+        /** Stores the command for retrieval later. */
+        @Override
+        public CommandResult runTimedCmd(long timeout, String... cmd) {
+            mCommand = Arrays.asList(cmd);
+            return new CommandResult(mResults.remove());
+        }
+
+        CommandArgumentCaptor setResult(CommandStatus status) {
+            mResults.add(status);
+            return this;
+        }
+
+        List<String> getCommand() {
+            return mCommand;
+        }
+
+        /** Ignores sleep calls. */
+        @Override
+        public void sleep(long ms) {}
+    }
+
+    /** Utility function to verify that certain suffixes are contained in the List. */
+    void checkListContainsSuffixes(List<String> list, List<String> suffixes) {
+        for (String suffix : suffixes) {
+            boolean found = false;
+            for (String item : list) {
+                if (item.endsWith(suffix)) {
+                    found = true;
+                    break;
+                }
+            }
+
+            if (!found) {
+                fail("List " + list.toString() + " does not contain suffix '" + suffix + "'");
+            }
+        }
+    }
+
+    void checkListDoesNotContainSuffix(List<String> list, String suffix) {
+        for (String item : list) {
+            if (item.endsWith(suffix)) {
+                fail("List " + list.toString() + " should not contain suffix '" + suffix + "'");
+            }
+        }
+    }
+}
diff --git a/src/com/android/tradefed/device/metric/ClangCodeCoverageCollector.java b/src/com/android/tradefed/device/metric/ClangCodeCoverageCollector.java
index b747692ba..1f784e95a 100644
--- a/src/com/android/tradefed/device/metric/ClangCodeCoverageCollector.java
+++ b/src/com/android/tradefed/device/metric/ClangCodeCoverageCollector.java
@@ -26,18 +26,15 @@ import com.android.tradefed.config.IConfiguration;
 import com.android.tradefed.config.IConfigurationReceiver;
 import com.android.tradefed.device.DeviceNotAvailableException;
 import com.android.tradefed.device.ITestDevice;
-import com.android.tradefed.error.HarnessRuntimeException;
 import com.android.tradefed.invoker.IInvocationContext;
 import com.android.tradefed.log.LogUtil.CLog;
 import com.android.tradefed.metrics.proto.MetricMeasurement.Metric;
 import com.android.tradefed.result.FileInputStreamSource;
 import com.android.tradefed.result.ITestInvocationListener;
 import com.android.tradefed.result.LogDataType;
-import com.android.tradefed.result.error.InfraErrorIdentifier;
 import com.android.tradefed.testtype.coverage.CoverageOptions;
 import com.android.tradefed.util.AdbRootElevator;
-import com.android.tradefed.util.CommandResult;
-import com.android.tradefed.util.CommandStatus;
+import com.android.tradefed.util.ClangProfileIndexer;
 import com.android.tradefed.util.FileUtil;
 import com.android.tradefed.util.IRunUtil;
 import com.android.tradefed.util.NativeCodeCoverageFlusher;
@@ -53,13 +50,8 @@ import java.io.File;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.OutputStream;
-import java.nio.charset.Charset;
-import java.nio.file.Files;
-import java.nio.file.Path;
-import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.HashSet;
-import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.TimeUnit;
@@ -70,11 +62,6 @@ import java.util.concurrent.TimeUnit;
  */
 public final class ClangCodeCoverageCollector extends BaseDeviceMetricCollector
         implements IConfigurationReceiver {
-    // Maximum number of profile files before writing the list to a file. Beyond this value,
-    // llvm-profdata will use the -f option to read the list from a file to prevent exceeding
-    // the command line length limit.
-    private static final int MAX_PROFILE_FILES = 100;
-
     // Finds .profraw files and compresses those files only. Stores the full
     // path of the file on the device.
     private static final String ZIP_CLANG_FILES_COMMAND_FORMAT =
@@ -152,7 +139,7 @@ public final class ClangCodeCoverageCollector extends BaseDeviceMetricCollector
         }
     }
 
-    /** Generate the .ec file prefix in format "$moduleName_MODULE_$runName". */
+    /** Generate the .profdata file prefix in format "$moduleName_MODULE_$runName". */
     private String generateMeasurementFileName() {
         String moduleName = Strings.nullToEmpty(getModuleName());
         if (moduleName.length() > 0) {
@@ -171,7 +158,6 @@ public final class ClangCodeCoverageCollector extends BaseDeviceMetricCollector
     private void logCoverageMeasurement(ITestDevice device, String runName)
             throws DeviceNotAvailableException, IOException {
         Map<String, File> untarDirs = new HashMap<>();
-        File fileList = null;
         File profileTool = null;
         File indexedProfileFile = null;
         try {
@@ -214,48 +200,12 @@ public final class ClangCodeCoverageCollector extends BaseDeviceMetricCollector
 
             CLog.i("Received %d Clang code coverage measurements.", rawProfileFiles.size());
 
-            // Get the llvm-profdata tool from the build. This tool must match the same one used to
-            // compile the build, otherwise this action will fail.
-            profileTool = getProfileTool();
-            Path profileBin = profileTool.toPath().resolve("bin/llvm-profdata");
-            profileBin.toFile().setExecutable(true);
-
-            List<String> command = new ArrayList<>();
-            command.add(profileBin.toString());
-            command.add("merge");
-            command.add("-sparse");
-
-            if (rawProfileFiles.size() > MAX_PROFILE_FILES) {
-                // Write the measurement file list to a temporary file. This allows large numbers
-                // of measurements to not exceed the command line length limit.
-                fileList = FileUtil.createTempFile("clang_measurements", ".txt");
-                Files.write(fileList.toPath(), rawProfileFiles, Charset.defaultCharset());
-
-                // Add the file containing the list of .profraw files.
-                command.add("-f");
-                command.add(fileList.getAbsolutePath());
-            } else {
-                command.addAll(rawProfileFiles);
-            }
+            ClangProfileIndexer indexer = new ClangProfileIndexer(getProfileTool(), mRunUtil);
 
             // Create the output file.
             indexedProfileFile =
                     FileUtil.createTempFile(runName + "_clang_runtime_coverage", ".profdata");
-            command.add("-o");
-            command.add(indexedProfileFile.getAbsolutePath());
-
-            CommandResult result = mRunUtil.runTimedCmd(0, command.toArray(new String[0]));
-            if (result.getStatus() != CommandStatus.SUCCESS) {
-                // Retry with -failure-mode=all to still be able to report some coverage.
-                command.add("-failure-mode=all");
-                result = mRunUtil.runTimedCmd(0, command.toArray(new String[0]));
-
-                if (result.getStatus() != CommandStatus.SUCCESS) {
-                    throw new HarnessRuntimeException(
-                            "Failed to merge Clang profile data:\n" + result.toString(),
-                            InfraErrorIdentifier.CODE_COVERAGE_ERROR);
-                }
-            }
+            indexer.index(rawProfileFiles, indexedProfileFile);
 
             try (FileInputStreamSource source =
                     new FileInputStreamSource(indexedProfileFile, true)) {
@@ -270,7 +220,6 @@ public final class ClangCodeCoverageCollector extends BaseDeviceMetricCollector
             for (File untarDir : untarDirs.values()) {
                 FileUtil.recursiveDelete(untarDir);
             }
-            FileUtil.deleteFile(fileList);
             FileUtil.recursiveDelete(mLlvmProfileTool);
             FileUtil.deleteFile(indexedProfileFile);
         }
diff --git a/src/com/android/tradefed/util/ClangProfileIndexer.java b/src/com/android/tradefed/util/ClangProfileIndexer.java
new file mode 100644
index 000000000..29e537be7
--- /dev/null
+++ b/src/com/android/tradefed/util/ClangProfileIndexer.java
@@ -0,0 +1,96 @@
+/*
+ * Copyright (C) 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.tradefed.util;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.charset.Charset;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+
+/** A utility class that indexes Clang code coverage measurements. */
+public final class ClangProfileIndexer {
+    // Maximum number of profile files before writing the list to a file. Beyond this value,
+    // llvm-profdata will use the -f option to read the list from a file to prevent exceeding
+    // the command line length limit.
+    private static final int MAX_PROFILE_FILES = 100;
+
+    private File mProfileTool;
+    private IRunUtil mRunUtil;
+
+    public ClangProfileIndexer(File profileTool) {
+        this(profileTool, RunUtil.getDefault());
+    }
+
+    public ClangProfileIndexer(File profileTool, IRunUtil runUtil) {
+        mProfileTool = profileTool;
+        mRunUtil = runUtil;
+    }
+
+    /**
+     * Indexes raw LLVM profile files and writes the coverage data to the output file.
+     *
+     * @param rawProfileFiles list of .profraw files to index
+     * @param outputFile file to write the results to
+     * @throws IOException on tool failure
+     */
+    public void index(Collection<String> rawProfileFiles, File outputFile) throws IOException {
+        Path profileBin = mProfileTool.toPath().resolve("bin/llvm-profdata");
+        profileBin.toFile().setExecutable(true);
+
+        List<String> command = new ArrayList<>();
+        command.add(profileBin.toString());
+        command.add("merge");
+        command.add("-sparse");
+
+        File fileList = null;
+        try {
+            if (rawProfileFiles.size() > MAX_PROFILE_FILES) {
+                // Write the measurement file list to a temporary file. This allows large numbers of
+                // measurements to not exceed the command line length limit.
+                fileList = FileUtil.createTempFile("clang_measurements", ".txt");
+                Files.write(fileList.toPath(), rawProfileFiles, Charset.defaultCharset());
+
+                // Add the file containing the list of .profraw files.
+                command.add("-f");
+                command.add(fileList.getAbsolutePath());
+            } else {
+                command.addAll(rawProfileFiles);
+            }
+
+            command.add("-o");
+            command.add(outputFile.getAbsolutePath());
+
+            CommandResult result = mRunUtil.runTimedCmd(0, command.toArray(new String[0]));
+            if (result.getStatus() != CommandStatus.SUCCESS) {
+                // Retry with -failure-mode=all to still be able to report some coverage.
+                command.add("-failure-mode=all");
+                result = mRunUtil.runTimedCmd(0, command.toArray(new String[0]));
+
+                if (result.getStatus() != CommandStatus.SUCCESS) {
+                    throw new IOException(
+                            "Failed to merge Clang profile data:\n" + result.toString());
+                }
+            }
+        } finally {
+            FileUtil.deleteFile(fileList);
+        }
+    }
+}
diff --git a/test_framework/com/android/tradefed/testtype/HostGTest.java b/test_framework/com/android/tradefed/testtype/HostGTest.java
index 358938c14..caee08b40 100644
--- a/test_framework/com/android/tradefed/testtype/HostGTest.java
+++ b/test_framework/com/android/tradefed/testtype/HostGTest.java
@@ -16,6 +16,8 @@
 
 package com.android.tradefed.testtype;
 
+import static com.android.tradefed.testtype.coverage.CoverageOptions.Toolchain.CLANG;
+
 import com.android.ddmlib.IShellOutputReceiver;
 import com.android.tradefed.build.BuildInfoKey.BuildInfoFileKey;
 import com.android.tradefed.build.DeviceBuildInfo;
@@ -35,6 +37,7 @@ import com.android.tradefed.result.ITestInvocationListener;
 import com.android.tradefed.result.LogDataType;
 import com.android.tradefed.result.error.TestErrorIdentifier;
 import com.android.tradefed.result.proto.TestRecordProto.FailureStatus;
+import com.android.tradefed.util.ClangProfileIndexer;
 import com.android.tradefed.util.CommandResult;
 import com.android.tradefed.util.CommandStatus;
 import com.android.tradefed.util.FileUtil;
@@ -145,6 +148,18 @@ public class HostGTest extends GTestBase implements IBuildReceiver {
             runUtil.setEnvVariable("LD_LIBRARY_PATH", ldLibraryPath);
         }
 
+        // Set LLVM_PROFILE_FILE for coverage.
+        File coverageDir = null;
+        if (isClangCoverageEnabled()) {
+            try {
+                coverageDir = FileUtil.createTempDir("clang");
+            } catch (IOException e) {
+                throw new RuntimeException(e);
+            }
+            runUtil.setEnvVariable(
+                    "LLVM_PROFILE_FILE", coverageDir.getAbsolutePath() + "/clang-%m.profraw");
+        }
+
         // If there's a shell output receiver to pass results along to, then
         // ShellOutputReceiverStream will write that into the IShellOutputReceiver. If not, the
         // command output will just be ignored.
@@ -186,6 +201,27 @@ public class HostGTest extends GTestBase implements IBuildReceiver {
                 }
             }
             FileUtil.deleteFile(stdout);
+
+            if (isClangCoverageEnabled()) {
+                File profdata = null;
+                try {
+                    Set<String> profraws = FileUtil.findFiles(coverageDir, ".*\\.profraw");
+                    ClangProfileIndexer indexer =
+                            new ClangProfileIndexer(
+                                    getConfiguration().getCoverageOptions().getLlvmProfdataPath());
+                    profdata = FileUtil.createTempFile(gtestFile.getName(), ".profdata");
+                    indexer.index(profraws, profdata);
+
+                    try (FileInputStreamSource source = new FileInputStreamSource(profdata, true)) {
+                        logger.testLog(gtestFile.getName(), LogDataType.CLANG_COVERAGE, source);
+                    }
+                } catch (IOException e) {
+                    throw new RuntimeException(e);
+                } finally {
+                    FileUtil.deleteFile(profdata);
+                    FileUtil.recursiveDelete(coverageDir);
+                }
+            }
         }
         return result;
     }
@@ -421,4 +457,10 @@ public class HostGTest extends GTestBase implements IBuildReceiver {
         }
         return new LinkedHashSet(seen.values());
     }
+
+    /** Returns whether Clang code coverage is enabled. */
+    private boolean isClangCoverageEnabled() {
+        return getConfiguration().getCoverageOptions().isCoverageEnabled()
+                && getConfiguration().getCoverageOptions().getCoverageToolchains().contains(CLANG);
+    }
 }