1 files changed, 196 insertions, 0 deletions
diff --git a/tools/test/LcovMerger/java/com/google/devtools/lcovmerger/GcovParser.java b/tools/test/LcovMerger/java/com/google/devtools/lcovmerger/GcovParser.java
new file mode 100644
index 0000000000..25592192b2
--- /dev/null
+++ b/tools/test/LcovMerger/java/com/google/devtools/lcovmerger/GcovParser.java
@@ -0,0 +1,196 @@
+// Copyright 2018 The Bazel Authors. All rights reserved.
+//
+// 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.google.devtools.lcovmerger;
+
+import static com.google.devtools.lcovmerger.Constants.DELIMITER;
+import static com.google.devtools.lcovmerger.Constants.GCOV_BRANCH_MARKER;
+import static com.google.devtools.lcovmerger.Constants.GCOV_BRANCH_NOTEXEC;
+import static com.google.devtools.lcovmerger.Constants.GCOV_BRANCH_NOTTAKEN;
+import static com.google.devtools.lcovmerger.Constants.GCOV_BRANCH_TAKEN;
+import static com.google.devtools.lcovmerger.Constants.GCOV_CWD_MARKER;
+import static com.google.devtools.lcovmerger.Constants.GCOV_FILE_MARKER;
+import static com.google.devtools.lcovmerger.Constants.GCOV_FUNCTION_MARKER;
+import static com.google.devtools.lcovmerger.Constants.GCOV_LINE_MARKER;
+import static com.google.devtools.lcovmerger.Constants.GCOV_VERSION_MARKER;
+import static java.nio.charset.StandardCharsets.UTF_8;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+/**
+ * A {@link Parser} for gcov intermediate format. See the flag {@code --intermediate-format} in <a
+ * href="https://gcc.gnu.org/onlinedocs/gcc/Invoking-gcov.html">gcov documentation</a>.
+ */
+public class GcovParser {
+
+  private static final Logger logger = Logger.getLogger(GcovParser.class.getName());
+  private List<SourceFileCoverage> allSourceFiles;
+  private final InputStream inputStream;
+  private SourceFileCoverage currentSourceFileCoverage;
+
+  private GcovParser(InputStream inputStream) {
+    this.inputStream = inputStream;
+  }
+
+  public static List<SourceFileCoverage> parse(InputStream inputStream) throws IOException {
+    return new GcovParser(inputStream).parse();
+  }
+
+  private List<SourceFileCoverage> parse() throws IOException {
+    allSourceFiles = new ArrayList<>();
+    boolean malformedInput = false;
+    try (BufferedReader bufferedReader =
+        new BufferedReader(new InputStreamReader(inputStream, UTF_8))) {
+      String line;
+      // TODO(bazel-team): This is susceptible to OOM if the input file is too large and doesn't
+      // contain any newlines.
+      while ((line = bufferedReader.readLine()) != null) {
+        if (!parseLine(line)) {
+          malformedInput = true;
+        }
+      }
+      bufferedReader.close();
+    }
+    endSourceFile();
+    if (malformedInput) {
+      throw new IOException("gcov intermediate input is malformed.");
+    }
+    return allSourceFiles;
+  }
+
+  /**
+   * Merges {@code currentSourceFileCoverage} into {@code allSourceFilesCoverageData} and resets
+   * {@code currentSourceFileCoverage} to null.
+   */
+  private void endSourceFile() {
+    if (currentSourceFileCoverage == null) {
+      return;
+    }
+    allSourceFiles.add(currentSourceFileCoverage);
+    currentSourceFileCoverage = null;
+  }
+
+  private boolean parseLine(String line) {
+    if (line.startsWith(GCOV_FILE_MARKER)) {
+      endSourceFile();
+      return parseSource(line);
+    }
+    if (line.startsWith(GCOV_FUNCTION_MARKER)) {
+      return parseFunction(line);
+    }
+    if (line.startsWith(GCOV_LINE_MARKER)) {
+      return parseLCount(line);
+    }
+    if (line.startsWith(GCOV_BRANCH_MARKER)) {
+      return parseBranch(line);
+    }
+    if (line.startsWith(GCOV_VERSION_MARKER) || line.startsWith(GCOV_CWD_MARKER)) {
+      // Ignore these fields for now as they are not necessary.
+      return true;
+    }
+    return false;
+  }
+
+  private boolean parseSource(String line) {
+    String sourcefile = line.substring(GCOV_FILE_MARKER.length());
+    if (sourcefile.isEmpty()) {
+      logger.log(Level.WARNING, "gcov info doesn't contain source file name on line: " + line);
+      return false;
+    }
+    currentSourceFileCoverage = new SourceFileCoverage(sourcefile);
+    return true;
+  }
+
+  // function:start_line_number,end_line_number,execution_count,function_name
+  private boolean parseFunction(String line) {
+    String lineContent = line.substring(GCOV_FUNCTION_MARKER.length());
+    String[] items = lineContent.split(DELIMITER, -1);
+    if (items.length != 4) {
+      logger.log(Level.WARNING, "gcov info contains invalid line " + line);
+      return false;
+    }
+    try {
+      // Ignore end_line_number since it's redundant information.
+      int startLine = Integer.parseInt(items[0]);
+      int execCount = Integer.parseInt(items[2]);
+      String functionName = items[3];
+      currentSourceFileCoverage.addLineNumber(functionName, startLine);
+      currentSourceFileCoverage.addFunctionExecution(functionName, execCount);
+    } catch (NumberFormatException e) {
+      logger.log(Level.WARNING, "gcov info contains invalid line " + line);
+      return false;
+    }
+    return true;
+  }
+
+  // lcount:line number,execution_count,has_unexecuted_block
+  private boolean parseLCount(String line) {
+    String lineContent = line.substring(GCOV_LINE_MARKER.length());
+    String[] items = lineContent.split(DELIMITER, -1);
+    if (items.length != 3) {
+      logger.log(Level.WARNING, "gcov info contains invalid line " + line);
+      return false;
+    }
+    try {
+      // Ignore has_unexecuted_block since it's not used.
+      int lineNr = Integer.parseInt(items[0]);
+      int execCount = Integer.parseInt(items[1]);
+      currentSourceFileCoverage.addLine(lineNr, LineCoverage.create(lineNr, execCount, null));
+    } catch (NumberFormatException e) {
+      logger.log(Level.WARNING, "gcov info contains invalid line " + line);
+      return false;
+    }
+    return true;
+  }
+
+  // branch:line_number,branch_coverage_type
+  private boolean parseBranch(String line) {
+    String lineContent = line.substring(GCOV_BRANCH_MARKER.length());
+    String[] items = lineContent.split(DELIMITER, -1);
+    if (items.length != 2) {
+      logger.log(Level.WARNING, "gcov info contains invalid line " + line);
+      return false;
+    }
+    try {
+      // Ignore has_unexecuted_block since it's not used.
+      int lineNr = Integer.parseInt(items[0]);
+      String type = items[1];
+      int execCount;
+      switch (type) {
+        case GCOV_BRANCH_NOTEXEC:
+          execCount = 0;
+          break;
+        case GCOV_BRANCH_NOTTAKEN:
+        case GCOV_BRANCH_TAKEN:
+          execCount = 1;
+          break;
+        default:
+          logger.log(Level.WARNING, "gcov info contains invalid line " + line);
+          return false;
+      }
+      currentSourceFileCoverage.addBranch(lineNr, BranchCoverage.create(lineNr, execCount));
+    } catch (NumberFormatException e) {
+      logger.log(Level.WARNING, "gcov info contains invalid line " + line);
+      return false;
+    }
+    return true;
+  }
+}