UnitTestFrameworkPkg: Add code coverage support for GCC

In order to collect code coverage after running executable
file, generate *.gcda and *.gcno file that require by lcov tool
to generate code coverage report.

Reviewed-by: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Sean Brogan <sean.brogan@microsoft.com>
Cc: Bret Barkelew <Bret.Barkelew@microsoft.com>
Reviewed-by: Michael Kubacki <mikuback@linux.microsoft.com>
Signed-off-by: Gua Guo <gua.guo@intel.com>

UnitTestFrameworkPkg/ReadMe.md

@@ -583,6 +583,47 @@ GTEST_OUTPUT=xml:<absolute or relative path to output file>
 
 This mode is used by the test running plugin to aggregate the results for CI test status reporting in the web view.
 
+### Code Coverage
+
+Host based Unit Tests will automatically enable coverage data.
+
+For Windows, This is primarily leverage for pipeline builds, but this can be leveraged locally using the
+OpenCppCoverage windows tool to parse coverage data to cobertura xml format.
+
+- Windows Prerequisite
+  ```bash
+  Download and install https://github.com/OpenCppCoverage/OpenCppCoverage/releases
+  python -m pip install --upgrade -r ./pip-requirements.txt
+  stuart_ci_build -c .pytool/CISettings.py  -t NOOPT TOOL_CHAIN_TAG=VS2019 -p MdeModulePkg
+  Open Build/coverage.xml
+  ```
+
+  - How to see code coverage data on IDE Visual Studio
+    ```
+    Open Visual Studio VS2019 or above version
+    Click "Tools" -> "OpenCppCoverage Settings"
+    Fill your execute file into "Program to run:"
+    Click "Tools" -> "Run OpenCppCoverage"
+    ```
+
+
+For Linux, This is primarily leveraged for pipeline builds, but this can be leveraged locally using the
+lcov linux tool, and parsed using the lcov_cobertura python tool to parse it to cobertura xml format.
+
+- Linux Prerequisite
+  ```bash
+  sudo apt-get install -y lcov
+  python -m pip install --upgrade -r ./pip-requirements.txt
+  stuart_ci_build -c .pytool/CISettings.py  -t NOOPT TOOL_CHAIN_TAG=GCC5 -p MdeModulePkg
+  Open Build/coverage.xml
+  ```
+  - How to see code coverage data on IDE Visual Studio Code
+    ```
+    Download plugin "Coverage Gutters"
+    Press Hot Key "Ctrl + Shift + P" and click option "Coverage Gutters: Display Coverage"
+    ```
+
+
 ### Important Note
 
 This works on both Windows and Linux but is currently limited to x64 architectures. Working on getting others, but we

UnitTestFrameworkPkg/UnitTestFrameworkPkg.ci.yaml

@@ -91,6 +91,7 @@
             "pytools",
             "NOFAILURE",
             "cmockery",
+            "cobertura",
             "DHAVE", # build flag for cmocka in the INF
             "gtest", # file name in GoogleTestLib.inf
             "corthon",      # Contact GitHub account in Readme

UnitTestFrameworkPkg/UnitTestFrameworkPkgHost.dsc.inc

@@ -27,7 +27,8 @@
   GCC:*_*_*_CC_FLAGS   = -D UNIT_TESTING_DEBUG=1
   XCODE:*_*_*_CC_FLAGS = -D UNIT_TESTING_DEBUG=1
 !endif
-
+  GCC:*_GCC5_*_CC_FLAGS = --coverage
+  GCC:*_GCC5_*_DLINK_FLAGS = --coverage
 [BuildOptions.common.EDKII.HOST_APPLICATION]
   #
   # MSFT