Autogen: Refactor RerunMocPlugin test with fixed timestamp comparison

This refactors and simplifies the QtAutogen.RerunMocPlugin test.
Repetitive task are packed into macros.
By using version strings to store file timestamps, timestamp comparison
becomes more reliable.  Test status and error messages are improved.

Tests/QtAutogen/RerunMocPlugin/CMakeLists.txt

@@ -9,10 +9,53 @@ include("../AutogenCoreTest.cmake")
 add_executable(dummy dummy.cpp)
 
 # Utility variables
-set(timeformat "%Y%j%H%M%S")
+set(timeformat "%Y.%j.%H.%M%S")
 set(mocPlugSrcDir "${CMAKE_CURRENT_SOURCE_DIR}/MocPlugin")
 set(mocPlugBinDir "${CMAKE_CURRENT_BINARY_DIR}/MocPlugin")
 
+# Utility macros
+macro(sleep)
+  message(STATUS "Sleeping for a few seconds.")
+  execute_process(COMMAND "${CMAKE_COMMAND}" -E sleep 1)
+endmacro()
+
+macro(rebuild buildName)
+  message(STATUS "Starting build ${buildName}.")
+  execute_process(COMMAND "${CMAKE_COMMAND}" --build . WORKING_DIRECTORY "${mocPlugBinDir}" RESULT_VARIABLE result)
+  if (result)
+    message(FATAL_ERROR "Build ${buildName} failed.")
+  else()
+    message(STATUS "Build ${buildName} finished.")
+  endif()
+endmacro()
+
+macro(require_change PLG)
+  if (pl${PLG}After VERSION_GREATER pl${PLG}Before)
+    message(STATUS "As expected the file ${pl${PLG}File} changed.")
+  else()
+    message(SEND_ERROR
+      "Unexpectedly the file ${pl${PLG}File} did not change!\nTimestamp pre: ${pl${PLG}Before}\nTimestamp aft: ${pl${PLG}After}\n")
+  endif()
+endmacro()
+
+macro(require_change_not PLG)
+  if (pl${PLG}After VERSION_GREATER pl${PLG}Before)
+    message(SEND_ERROR
+      "Unexpectedly the file ${pl${PLG}File} changed!\nTimestamp pre: ${pl${PLG}Before}\nTimestamp aft: ${pl${PLG}After}\n")
+  else()
+    message(STATUS "As expected the file ${pl${PLG}File} did not change.")
+  endif()
+endmacro()
+
+macro(acquire_timestamps When)
+  file(TIMESTAMP "${plAFile}" plA${When} "${timeformat}")
+  file(TIMESTAMP "${plBFile}" plB${When} "${timeformat}")
+  file(TIMESTAMP "${plCFile}" plC${When} "${timeformat}")
+  file(TIMESTAMP "${plDFile}" plD${When} "${timeformat}")
+  file(TIMESTAMP "${plEFile}" plE${When} "${timeformat}")
+endmacro()
+
+
 # Initial build
 try_compile(MOC_PLUGIN
   "${mocPlugBinDir}"
@@ -24,83 +67,75 @@ try_compile(MOC_PLUGIN
   OUTPUT_VARIABLE output
 )
 if (NOT MOC_PLUGIN)
-  message(SEND_ERROR "Initial build of mocPlugin failed. Output: ${output}")
+  message(FATAL_ERROR "Initial build of mocPlugin failed. Output: ${output}")
 endif()
 
+# Get names of the output binaries
 find_library(plAFile "PlugA" PATHS "${mocPlugBinDir}/Debug" "${mocPlugBinDir}" NO_DEFAULT_PATH)
 find_library(plBFile "PlugB" PATHS "${mocPlugBinDir}/Debug" "${mocPlugBinDir}" NO_DEFAULT_PATH)
 find_library(plCFile "PlugC" PATHS "${mocPlugBinDir}/Debug" "${mocPlugBinDir}" NO_DEFAULT_PATH)
 find_library(plDFile "PlugD" PATHS "${mocPlugBinDir}/Debug" "${mocPlugBinDir}" NO_DEFAULT_PATH)
 find_library(plEFile "PlugE" PATHS "${mocPlugBinDir}/Debug" "${mocPlugBinDir}" NO_DEFAULT_PATH)
 
+# To avoid a race condition where the library has the same timestamp
+# as a source file and therefore gets rebuild
+# - sleep to ensure a timestamp change
+# - touch library to ensure it has a new timestamp
+acquire_timestamps(Before)
+sleep()
+message(STATUS "Touching library files to ensure new timestamps")
+file(TOUCH_NOCREATE "${plAFile}" "${plBFile}" "${plCFile}" "${plDFile}" "${plEFile}")
+acquire_timestamps(After)
+require_change(A)
+require_change(B)
+require_change(C)
+require_change(D)
+require_change(E)
+
+
 # - Ensure that the timestamp will change.
 # - Change the json files referenced by Q_PLUGIN_METADATA
 # - Rebuild
-file(TIMESTAMP "${plAFile}" plABefore "${timeformat}")
-file(TIMESTAMP "${plBFile}" plBBefore "${timeformat}")
-file(TIMESTAMP "${plCFile}" plCBefore "${timeformat}")
-file(TIMESTAMP "${plDFile}" plDBefore "${timeformat}")
-file(TIMESTAMP "${plEFile}" plEBefore "${timeformat}")
-
-execute_process(COMMAND "${CMAKE_COMMAND}" -E sleep 1)
+acquire_timestamps(Before)
+sleep()
+message(STATUS "Changing json files")
 configure_file("${mocPlugSrcDir}/jsonIn/StyleD.json" "${mocPlugBinDir}/jsonFiles/StyleC.json")
 configure_file("${mocPlugSrcDir}/jsonIn/StyleE.json" "${mocPlugBinDir}/jsonFiles/sub/StyleD.json")
 configure_file("${mocPlugSrcDir}/jsonIn/StyleC.json" "${mocPlugBinDir}/jsonFiles/StyleE.json")
-execute_process(COMMAND "${CMAKE_COMMAND}" --build . WORKING_DIRECTORY "${mocPlugBinDir}")
-
-file(TIMESTAMP "${plAFile}" plAAfter "${timeformat}")
-file(TIMESTAMP "${plBFile}" plBAfter "${timeformat}")
-file(TIMESTAMP "${plCFile}" plCAfter "${timeformat}")
-file(TIMESTAMP "${plDFile}" plDAfter "${timeformat}")
-file(TIMESTAMP "${plEFile}" plEAfter "${timeformat}")
-
-if (plAAfter GREATER plABefore)
-  message(SEND_ERROR "file (${plAFile}) should not have changed!")
-endif()
-if (plBAfter GREATER plBBefore)
-  message(SEND_ERROR "file (${plBFile}) should not have changed!")
-endif()
-if (NOT plCAfter GREATER plCBefore)
-  message(SEND_ERROR "file (${plCFile}) should have changed!")
-endif()
-if (NOT plDAfter GREATER plDBefore)
-  message(SEND_ERROR "file (${plDFile}) should have changed!")
-endif()
-if (NOT plEAfter GREATER plEBefore)
-  # There's a bug in Ninja on Windows
-  # https://gitlab.kitware.com/cmake/cmake/issues/16776
-  if(NOT ("${CMAKE_GENERATOR}" MATCHES "Ninja"))
-    message(SEND_ERROR "file (${plEFile}) should have changed!")
-  endif()
+sleep()
+rebuild(2)
+acquire_timestamps(After)
+# Test changes
+require_change_not(A)
+require_change_not(B)
+require_change(C)
+require_change(D)
+# There's a bug in Ninja on Windows:
+# https://gitlab.kitware.com/cmake/cmake/issues/16776
+if(NOT ("${CMAKE_GENERATOR}" MATCHES "Ninja"))
+  require_change(E)
 endif()
 
+
 # - Ensure that the timestamp will change.
 # - Change the json files referenced by A_CUSTOM_MACRO
 # - Rebuild
-file(TIMESTAMP "${plCFile}" plCBefore "${timeformat}")
-file(TIMESTAMP "${plDFile}" plDBefore "${timeformat}")
-file(TIMESTAMP "${plEFile}" plEBefore "${timeformat}")
-
-execute_process(COMMAND "${CMAKE_COMMAND}" -E sleep 1)
+acquire_timestamps(Before)
+sleep()
+message(STATUS "Changing json files")
 configure_file("${mocPlugSrcDir}/jsonIn/StyleE.json" "${mocPlugBinDir}/jsonFiles/StyleC_Custom.json")
 configure_file("${mocPlugSrcDir}/jsonIn/StyleC.json" "${mocPlugBinDir}/jsonFiles/sub/StyleD_Custom.json")
 configure_file("${mocPlugSrcDir}/jsonIn/StyleD.json" "${mocPlugBinDir}/jsonFiles/StyleE_Custom.json")
-execute_process(COMMAND "${CMAKE_COMMAND}" --build . WORKING_DIRECTORY "${mocPlugBinDir}")
-
-file(TIMESTAMP "${plCFile}" plCAfter "${timeformat}")
-file(TIMESTAMP "${plDFile}" plDAfter "${timeformat}")
-file(TIMESTAMP "${plEFile}" plEAfter "${timeformat}")
-
-if (NOT plCAfter GREATER plCBefore)
-  message(SEND_ERROR "file (${plCFile}) should have changed!")
-endif()
-if (NOT plDAfter GREATER plDBefore)
-  message(SEND_ERROR "file (${plDFile}) should have changed!")
-endif()
-if (NOT plEAfter GREATER plEBefore)
-  # There's a bug in Ninja on Windows
-  # https://gitlab.kitware.com/cmake/cmake/issues/16776
-  if(NOT ("${CMAKE_GENERATOR}" MATCHES "Ninja"))
-    message(SEND_ERROR "file (${plEFile}) should have changed!")
-  endif()
+sleep()
+rebuild(3)
+acquire_timestamps(After)
+# Test changes
+require_change_not(A)
+require_change_not(B)
+require_change(C)
+require_change(D)
+# There's a bug in Ninja on Windows
+# https://gitlab.kitware.com/cmake/cmake/issues/16776
+if(NOT ("${CMAKE_GENERATOR}" MATCHES "Ninja"))
+  require_change(E)
 endif()