gtest_discover_tests: Re-run PRE_TEST discovery on any arg change

Fixes: #22912

Modules/GoogleTest.cmake

@@ -513,7 +513,8 @@ function(gtest_discover_tests TARGET)
     string(CONCAT ctest_include_content
       "if(EXISTS \"$<TARGET_FILE:${TARGET}>\")"                                    "\n"
       "  if(NOT EXISTS \"${ctest_tests_file}\" OR"                                 "\n"
-      "     NOT \"${ctest_tests_file}\" IS_NEWER_THAN \"$<TARGET_FILE:${TARGET}>\")" "\n"
+      "     NOT \"${ctest_tests_file}\" IS_NEWER_THAN \"$<TARGET_FILE:${TARGET}>\" OR\n"
+      "     NOT \"${ctest_tests_file}\" IS_NEWER_THAN \"\${CMAKE_CURRENT_LIST_FILE}\")\n"
       "    include(\"${_GOOGLETEST_DISCOVER_TESTS_SCRIPT}\")"                      "\n"
       "    gtest_discover_tests_impl("                                             "\n"
       "      TEST_EXECUTABLE"        " [==[" "$<TARGET_FILE:${TARGET}>"   "]==]"   "\n"

Tests/RunCMake/GoogleTest/GoogleTest-discovery-arg-change-basic-stdout.txt

@@ -0,0 +1,7 @@
+Test project .*/Tests/RunCMake/GoogleTest/GoogleTest-discovery-arg-change
+  Test #1: basic\.case_foo
+  Test #2: basic\.case_bar
+  Test #3: basic\.disabled_case \(Disabled\)
+  Test #4: basic\.DISABLEDnot_really_case
+
+Total Tests: 4

Tests/RunCMake/GoogleTest/GoogleTest-discovery-arg-change-typed-stdout.txt

@@ -0,0 +1,5 @@
+Test project .*/Tests/RunCMake/GoogleTest/GoogleTest-discovery-arg-change
+  Test #1: typed/short\.case
+  Test #2: typed/float\.case
+
+Total Tests: 2

Tests/RunCMake/GoogleTest/GoogleTestDiscoveryArgChange.cmake

@@ -0,0 +1,14 @@
+enable_language(CXX)
+include(GoogleTest)
+
+enable_testing()
+
+include(xcode_sign_adhoc.cmake)
+
+add_executable(fake_gtest fake_gtest.cpp)
+xcode_sign_adhoc(fake_gtest)
+
+gtest_discover_tests(
+  fake_gtest
+  TEST_FILTER "${TEST_FILTER}*"
+)

Tests/RunCMake/GoogleTest/RunCMakeTest.cmake

@@ -1,5 +1,12 @@
 include(RunCMake)
 
+if(RunCMake_GENERATOR STREQUAL "Borland Makefiles" OR
+   RunCMake_GENERATOR STREQUAL "Watcom WMake")
+  set(fs_delay 3)
+else()
+  set(fs_delay 1.125)
+endif()
+
 function(run_GoogleTest DISCOVERY_MODE)
   # Use a single build tree for a few tests without cleaning.
   set(RunCMake_TEST_BINARY_DIR ${RunCMake_BINARY_DIR}/GoogleTest-build)
@@ -153,6 +160,46 @@ function(run_GoogleTest_discovery_timeout DISCOVERY_MODE)
   )
 endfunction()
 
+function(run_GoogleTest_discovery_arg_change DISCOVERY_MODE)
+  # Use a single build tree for a few tests without cleaning.
+  set(RunCMake_TEST_BINARY_DIR ${RunCMake_BINARY_DIR}/GoogleTest-discovery-arg-change)
+  set(RunCMake_TEST_NO_CLEAN 1)
+  file(REMOVE_RECURSE "${RunCMake_TEST_BINARY_DIR}")
+  file(MAKE_DIRECTORY "${RunCMake_TEST_BINARY_DIR}")
+
+  run_cmake_with_options(GoogleTestDiscoveryArgChange
+    -DCMAKE_GTEST_DISCOVER_TESTS_DISCOVERY_MODE=${DISCOVERY_MODE}
+    -DTEST_FILTER=basic
+  )
+  run_cmake_command(GoogleTest-discovery-arg-change-build
+    ${CMAKE_COMMAND}
+    --build .
+    --config Release
+    --target fake_gtest
+  )
+  run_cmake_command(GoogleTest-discovery-arg-change-basic
+    ${CMAKE_CTEST_COMMAND}
+    -C Release
+    -N
+  )
+  execute_process(COMMAND ${CMAKE_COMMAND} -E sleep ${fs_delay}) # handle 1s resolution
+  run_cmake_with_options(GoogleTestDiscoveryArgChange
+    -DCMAKE_GTEST_DISCOVER_TESTS_DISCOVERY_MODE=${DISCOVERY_MODE}
+    -DTEST_FILTER=typed
+  )
+  run_cmake_command(GoogleTest-discovery-arg-change-build
+    ${CMAKE_COMMAND}
+    --build .
+    --config Release
+    --target fake_gtest
+  )
+  run_cmake_command(GoogleTest-discovery-arg-change-typed
+    ${CMAKE_CTEST_COMMAND}
+    -C Release
+    -N
+  )
+endfunction()
+
 function(run_GoogleTest_discovery_multi_config)
   # Use a single build tree for a few tests without cleaning.
   set(RunCMake_TEST_BINARY_DIR ${RunCMake_BINARY_DIR}/GoogleTest-discovery-multi-config)
@@ -195,6 +242,10 @@ foreach(DISCOVERY_MODE POST_BUILD PRE_TEST)
   run_GoogleTestXML(${DISCOVERY_MODE})
   message("Testing ${DISCOVERY_MODE} discovery mode via DISCOVERY_MODE option...")
   run_GoogleTest_discovery_timeout(${DISCOVERY_MODE})
+  if(# VS 9 does not rebuild if POST_BUILD command changes.
+      NOT "${DISCOVERY_MODE};${RunCMake_GENERATOR}" MATCHES "^POST_BUILD;Visual Studio 9")
+    run_GoogleTest_discovery_arg_change(${DISCOVERY_MODE})
+  endif()
 endforeach()
 
 if(RunCMake_GENERATOR_IS_MULTI_CONFIG)