Implement LcovMerger.

LcovMerger is a tool that merges all the intermediate lcov tracefiles (with .dat extension) found under a coverage directory and prints the merged tracefile to a given output file.

A custom implementation for merging lcov tracefiles is needed because the merging functionality of lcov itself is very slow.

LcovMerger is required to get a single coverage report (lcov tracefile) from a bazel coverage command that executes multiple tests.

ATM LcovMerger is only invoked by tools/test/collect_coverage.sh that collects and merges the tracefiles from a single test invocation. It will also be used from a CoverageReportAction.

Progress on #5246.

PiperOrigin-RevId: 200054506

1 files changed, 106 insertions, 0 deletions

diff --git a/tools/test/LcovMerger/java/com/google/devtools/lcovmerger/BUILD b/tools/test/LcovMerger/java/com/google/devtools/lcovmerger/BUILD
new file mode 100644
index 0000000000..b7d4d7b08c
--- /dev/null
+++ b/tools/test/LcovMerger/java/com/google/devtools/lcovmerger/BUILD
@@ -0,0 +1,106 @@
+package(
+    default_visibility = [
+        "//tools/test/LcovMerger/javatests/com/google/devtools/lcovmerger:__pkg__",
+    ],
+)
+
+licenses(["notice"])  # Apache 2.0
+
+java_library(
+    name = "BranchCoverage",
+    srcs = ["BranchCoverage.java"],
+    deps = [
+        "//third_party:auto_value",
+    ],
+)
+
+java_library(
+    name = "LineCoverage",
+    srcs = ["LineCoverage.java"],
+    deps = [
+        "//third_party:auto_value",
+        "//third_party:jsr305",
+    ],
+)
+
+java_library(
+    name = "SourceFileCoverage",
+    srcs = ["SourceFileCoverage.java"],
+    deps = [
+        ":BranchCoverage",
+        ":LineCoverage",
+        "//third_party:auto_value",
+        "//third_party:guava",
+        "//third_party:jsr305",
+    ],
+)
+
+java_library(
+    name = "LcovPrinter",
+    srcs = ["LcovPrinter.java"],
+    deps = [
+        ":BranchCoverage",
+        ":Coverage",
+        ":LcovConstants",
+        ":LineCoverage",
+        ":SourceFileCoverage",
+        "//third_party:guava",
+    ],
+)
+
+java_library(
+    name = "LcovConstants",
+    srcs = ["LcovConstants.java"],
+)
+
+java_library(
+    name = "LcovParser",
+    srcs = ["LcovParser.java"],
+    deps = [
+        ":BranchCoverage",
+        ":LcovConstants",
+        ":LineCoverage",
+        ":SourceFileCoverage",
+    ],
+)
+
+java_library(
+    name = "Coverage",
+    srcs = ["Coverage.java"],
+    deps = [":SourceFileCoverage"],
+)
+
+java_library(
+    name = "MainLibrary",
+    srcs = ["Main.java"],
+    deps = [
+        ":Coverage",
+        ":LcovConstants",
+        ":LcovParser",
+        ":LcovPrinter",
+        ":SourceFileCoverage",
+        "//third_party:guava",
+    ],
+)
+
+java_binary(
+    name = "Main",
+    srcs = ["Main.java"],
+    main_class = "com.google.devtools.lcovmerger.Main",
+    visibility = ["//visibility:public"],
+    deps = [
+        ":Coverage",
+        ":LcovConstants",
+        ":LcovParser",
+        ":LcovPrinter",
+        ":MainLibrary",
+        ":SourceFileCoverage",
+        "//third_party:guava",
+    ],
+)
+
+filegroup(
+    name = "srcs",
+    srcs = glob(["**"]),
+    visibility = ["//visibility:public"],
+)