ExternalProject: Add CONFIGURE_HANDLED_BY_BUILD option

Fixes #21592.

3 files changed, 77 insertions, 0 deletions

diff --git a/Tests/RunCMake/ExternalProject/CONFIGURE_HANDLED_BY_BUILD-rebuild-check.cmake b/Tests/RunCMake/ExternalProject/CONFIGURE_HANDLED_BY_BUILD-rebuild-check.cmake
new file mode 100644
index 0000000..887da0f
--- /dev/null
+++ b/Tests/RunCMake/ExternalProject/CONFIGURE_HANDLED_BY_BUILD-rebuild-check.cmake
@@ -0,0 +1,19 @@
+file(TIMESTAMP "${STAMP_DIR}/proj1-configure" PROJ1_CONFIGURE_TIMESTAMP_AFTER "%s")
+# When BUILD_ALWAYS is set, the build stamp is never created.
+file(TIMESTAMP "${STAMP_DIR}/proj2-configure" PROJ2_CONFIGURE_TIMESTAMP_AFTER "%s")
+file(TIMESTAMP "${STAMP_DIR}/proj2-build" PROJ2_BUILD_TIMESTAMP_AFTER "%s")
+
+if(NOT PROJ1_CONFIGURE_TIMESTAMP_BEFORE EQUAL PROJ1_CONFIGURE_TIMESTAMP_AFTER)
+  set(RunCMake_TEST_FAILED "Unexpected rebuild of proj1 configure step (${PROJ1_CONFIGURE_TIMESTAMP_BEFORE} != ${PROJ1_CONFIGURE_TIMESTAMP_AFTER})")
+  return()
+endif()
+
+if(NOT PROJ2_CONFIGURE_TIMESTAMP_BEFORE EQUAL PROJ2_CONFIGURE_TIMESTAMP_AFTER)
+  set(RunCMake_TEST_FAILED "Unexpected rebuild of proj2 configure step (${PROJ2_CONFIGURE_TIMESTAMP_BEFORE} != ${PROJ2_CONFIGURE_TIMESTAMP_AFTER})")
+  return()
+endif()
+
+if(PROJ2_BUILD_TIMESTAMP_BEFORE EQUAL PROJ2_BUILD_TIMESTAMP_AFTER)
+  set(RunCMake_TEST_FAILED "proj2 build step did not rebuild (${PROJ2_BUILD_TIMESTAMP_BEFORE} != ${PROJ2_BUILD_TIMESTAMP_AFTER})")
+  return()
+endif()
diff --git a/Tests/RunCMake/ExternalProject/CONFIGURE_HANDLED_BY_BUILD.cmake b/Tests/RunCMake/ExternalProject/CONFIGURE_HANDLED_BY_BUILD.cmake
new file mode 100644
index 0000000..c86a60e
--- /dev/null
+++ b/Tests/RunCMake/ExternalProject/CONFIGURE_HANDLED_BY_BUILD.cmake
@@ -0,0 +1,28 @@
+include(ExternalProject)
+
+# Given this setup, on the first build, both configure steps and both build
+# steps will run. On a noop rebuild, only the build steps will run. Without
+# CONFIGURE_HANDLED_BY_BUILD, the configure step of proj2 would also run on a
+# noop rebuild.
+
+ExternalProject_Add(proj1
+  DOWNLOAD_COMMAND ""
+  SOURCE_DIR ""
+  CONFIGURE_COMMAND ${CMAKE_COMMAND} -E echo "Doing something"
+  # file(TIMESTAMP) gives back the timestamp in seconds so we sleep a second to
+  # make sure we get a different timestamp on the stamp file
+  BUILD_COMMAND ${CMAKE_COMMAND} -E sleep 1
+  INSTALL_COMMAND ""
+  BUILD_ALWAYS ON
+  STAMP_DIR "stamp"
+)
+ExternalProject_Add(proj2
+  DOWNLOAD_COMMAND ""
+  SOURCE_DIR ""
+  CONFIGURE_COMMAND ${CMAKE_COMMAND} -E echo "Doing something"
+  BUILD_COMMAND ${CMAKE_COMMAND} -E sleep 1
+  INSTALL_COMMAND ""
+  CONFIGURE_HANDLED_BY_BUILD ON
+  DEPENDS proj1
+  STAMP_DIR "stamp"
+)
diff --git a/Tests/RunCMake/ExternalProject/RunCMakeTest.cmake b/Tests/RunCMake/ExternalProject/RunCMakeTest.cmake
index 598671f..22b8d24 100644
--- a/Tests/RunCMake/ExternalProject/RunCMakeTest.cmake
+++ b/Tests/RunCMake/ExternalProject/RunCMakeTest.cmake
@@ -151,3 +151,33 @@ endif()
 if(doSubstitutionTest)
     __ep_test_with_build(Substitutions)
 endif()
+
+function(__ep_test_CONFIGURE_HANDLED_BY_BUILD)
+  set(RunCMake_TEST_BINARY_DIR ${RunCMake_BINARY_DIR}/CONFIGURE_HANDLED_BY_BUILD-build)
+  run_cmake(CONFIGURE_HANDLED_BY_BUILD)
+
+  if(RunCMake_GENERATOR_IS_MULTI_CONFIG)
+    set(BUILD_CONFIG --config Debug)
+    set(STAMP_DIR "${RunCMake_TEST_BINARY_DIR}/stamp/Debug")
+  else()
+    set(BUILD_CONFIG "")
+    set(STAMP_DIR "${RunCMake_TEST_BINARY_DIR}/stamp")
+  endif()
+
+  set(RunCMake_TEST_NO_CLEAN 1)
+  run_cmake_command(CONFIGURE_HANDLED_BY_BUILD-build ${CMAKE_COMMAND} --build . ${BUILD_CONFIG})
+
+  # Calculate timestamps before rebuilding so we can compare before and after in
+  # CONFIGURE_HANDLED_BY_BUILD-rebuild-check.cmake
+
+  file(TIMESTAMP "${STAMP_DIR}/proj1-configure" PROJ1_CONFIGURE_TIMESTAMP_BEFORE "%s")
+  # When BUILD_ALWAYS is set, the build stamp is never created.
+  file(TIMESTAMP "${STAMP_DIR}/proj2-configure" PROJ2_CONFIGURE_TIMESTAMP_BEFORE "%s")
+  file(TIMESTAMP "${STAMP_DIR}/proj2-build" PROJ2_BUILD_TIMESTAMP_BEFORE "%s")
+
+  run_cmake_command(CONFIGURE_HANDLED_BY_BUILD-rebuild ${CMAKE_COMMAND} --build . ${BUILD_CONFIG})
+endfunction()
+
+if(NOT RunCMake_GENERATOR MATCHES "Visual Studio 9 ")
+  __ep_test_CONFIGURE_HANDLED_BY_BUILD()
+endif()