CTest: Optionally add a ChangeId attribute on XML Site tags

Add variable CTEST_CHANGE_ID to configure the setting.  This allows
CTest clients to give CDash information about what change is being
tested so that CDash can take actions to report the results (e.g. to a
pull request page).

9 files changed, 67 insertions, 0 deletions

diff --git a/Help/manual/cmake-variables.7.rst b/Help/manual/cmake-variables.7.rst
index f54436a..19d0c68 100644
--- a/Help/manual/cmake-variables.7.rst
+++ b/Help/manual/cmake-variables.7.rst
@@ -351,6 +351,7 @@ Variables for CTest
    /variable/CTEST_BUILD_NAME
    /variable/CTEST_BZR_COMMAND
    /variable/CTEST_BZR_UPDATE_OPTIONS
+   /variable/CTEST_CHANGE_ID
    /variable/CTEST_CHECKOUT_COMMAND
    /variable/CTEST_CONFIGURATION_TYPE
    /variable/CTEST_CONFIGURE_COMMAND
diff --git a/Help/variable/CTEST_CHANGE_ID.rst b/Help/variable/CTEST_CHANGE_ID.rst
new file mode 100644
index 0000000..a423f49
--- /dev/null
+++ b/Help/variable/CTEST_CHANGE_ID.rst
@@ -0,0 +1,9 @@
+CTEST_CHANGE_ID
+---------------
+
+Specify the CTest ``ChangeId`` setting
+in a :manual:`ctest(1)` dashboard client script.
+
+This setting allows CTest to pass arbitrary information about this
+build up to CDash.  One use of this feature is to allow CDash to
+post comments on your pull request if anything goes wrong with your build.
diff --git a/Source/CTest/cmCTestHandlerCommand.cxx b/Source/CTest/cmCTestHandlerCommand.cxx
index 3003e8a..3579aee 100644
--- a/Source/CTest/cmCTestHandlerCommand.cxx
+++ b/Source/CTest/cmCTestHandlerCommand.cxx
@@ -109,6 +109,12 @@ bool cmCTestHandlerCommand
       this->Quiet);
     }
 
+  if(const char* changeId =
+     this->Makefile->GetDefinition("CTEST_CHANGE_ID"))
+    {
+    this->CTest->SetCTestConfiguration("ChangeId", changeId, this->Quiet);
+    }
+
   cmCTestLog(this->CTest, DEBUG, "Initialize handler" << std::endl;);
   cmCTestGenericHandler* handler = this->InitializeHandler();
   if ( !handler )
diff --git a/Source/cmCTest.cxx b/Source/cmCTest.cxx
index 5676dda..f65bd29 100644
--- a/Source/cmCTest.cxx
+++ b/Source/cmCTest.cxx
@@ -1567,6 +1567,13 @@ void cmCTest::StartXML(cmXMLWriter& xml, bool append)
   xml.Attribute("LogicalProcessorsPerPhysical",
                      info.GetLogicalProcessorsPerPhysical());
   xml.Attribute("ProcessorClockFrequency", info.GetProcessorClockFrequency());
+
+  std::string changeId = this->GetCTestConfiguration("ChangeId");
+  if(!changeId.empty())
+    {
+    xml.Attribute("ChangeId", changeId);
+    }
+
   this->AddSiteProperties(xml);
 }
 
diff --git a/Tests/RunCMake/ctest_build/BuildChangeId-check.cmake b/Tests/RunCMake/ctest_build/BuildChangeId-check.cmake
new file mode 100644
index 0000000..074801f
--- /dev/null
+++ b/Tests/RunCMake/ctest_build/BuildChangeId-check.cmake
@@ -0,0 +1,12 @@
+file(GLOB build_xml_file "${RunCMake_TEST_BINARY_DIR}/Testing/*/Build.xml")
+if(build_xml_file)
+  file(READ "${build_xml_file}" build_xml LIMIT 4096)
+  if(NOT build_xml MATCHES [[ChangeId="&lt;&gt;1"]])
+    string(REPLACE "\n" "\n  " build_xml "  ${build_xml}")
+    set(RunCMake_TEST_FAILED
+      "Build.xml does not have expected ChangeId:\n${build_xml}"
+      )
+  endif()
+else()
+  set(RunCMake_TEST_FAILED "Build.xml not found")
+endif()
diff --git a/Tests/RunCMake/ctest_build/RunCMakeTest.cmake b/Tests/RunCMake/ctest_build/RunCMakeTest.cmake
index c6f732c..324f25c 100644
--- a/Tests/RunCMake/ctest_build/RunCMakeTest.cmake
+++ b/Tests/RunCMake/ctest_build/RunCMakeTest.cmake
@@ -31,3 +31,12 @@ endif()
   endif()
 endfunction()
 run_BuildFailure()
+
+function(run_BuildChangeId)
+  set(CASE_TEST_PREFIX_CODE [[
+    set(CTEST_CHANGE_ID "<>1")
+  ]])
+
+  run_ctest(BuildChangeId)
+endfunction()
+run_BuildChangeId()
diff --git a/Tests/RunCMake/ctest_test/RunCMakeTest.cmake b/Tests/RunCMake/ctest_test/RunCMakeTest.cmake
index 21d0447..76dc143 100644
--- a/Tests/RunCMake/ctest_test/RunCMakeTest.cmake
+++ b/Tests/RunCMake/ctest_test/RunCMakeTest.cmake
@@ -49,3 +49,13 @@ set(CASE_CTEST_TEST_LOAD "ERR3")
 run_ctest_test(TestLoadOrder TEST_LOAD "ERR4")
 
 unset(ENV{__CTEST_FAKE_LOAD_AVERAGE_FOR_TESTING})
+unset(CASE_CTEST_TEST_LOAD)
+
+function(run_TestChangeId)
+  set(CASE_TEST_PREFIX_CODE [[
+    set(CTEST_CHANGE_ID "<>1")
+  ]])
+
+  run_ctest(TestChangeId)
+endfunction()
+run_TestChangeId()
diff --git a/Tests/RunCMake/ctest_test/TestChangeId-check.cmake b/Tests/RunCMake/ctest_test/TestChangeId-check.cmake
new file mode 100644
index 0000000..b9884f1
--- /dev/null
+++ b/Tests/RunCMake/ctest_test/TestChangeId-check.cmake
@@ -0,0 +1,12 @@
+file(GLOB test_xml_file "${RunCMake_TEST_BINARY_DIR}/Testing/*/Test.xml")
+if(test_xml_file)
+  file(READ "${test_xml_file}" test_xml LIMIT 4096)
+  if(NOT test_xml MATCHES [[ChangeId="&lt;&gt;1"]])
+    string(REPLACE "\n" "\n  " test_xml "  ${test_xml}")
+    set(RunCMake_TEST_FAILED
+      "Test.xml does not have expected ChangeId:\n${test_xml}"
+      )
+  endif()
+else()
+  set(RunCMake_TEST_FAILED "Test.xml not found")
+endif()
diff --git a/Tests/RunCMake/ctest_test/test.cmake.in b/Tests/RunCMake/ctest_test/test.cmake.in
index a8de6a3..50b936d 100644
--- a/Tests/RunCMake/ctest_test/test.cmake.in
+++ b/Tests/RunCMake/ctest_test/test.cmake.in
@@ -1,4 +1,5 @@
 cmake_minimum_required(VERSION 3.1)
+@CASE_TEST_PREFIX_CODE@
 
 set(CTEST_SITE                          "test-site")
 set(CTEST_BUILD_NAME                    "test-build-name")