Merge topic 'externalproject-update-refactor'

ac6a4d4884 ExternalProject: Improve robustness of update step
17c4c8b92b Tests: Prevent the noisy CMP0114 warnings in ExternalProjectUpdate test
1cb65e680d ExternalProject: Prevent the noisy detached head messages on checkout

Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !5389

3 files changed, 91 insertions, 0 deletions

diff --git a/Tests/RunCMake/ExternalProject/FetchGitTags.cmake b/Tests/RunCMake/ExternalProject/FetchGitTags.cmake
new file mode 100644
index 0000000..37d1b40
--- /dev/null
+++ b/Tests/RunCMake/ExternalProject/FetchGitTags.cmake
@@ -0,0 +1,67 @@
+find_package(Git QUIET REQUIRED)
+
+include(ExternalProject)
+
+set(srcRepo ${CMAKE_CURRENT_BINARY_DIR}/srcRepo)
+set(srcDir  ${CMAKE_CURRENT_BINARY_DIR}/src)
+set(binDir  ${CMAKE_CURRENT_BINARY_DIR}/build)
+file(MAKE_DIRECTORY ${srcRepo})
+file(MAKE_DIRECTORY ${srcDir})
+
+file(GLOB entries ${srcRepo}/*)
+file(REMOVE_RECURSE ${entries} ${binDir})
+file(TOUCH ${srcRepo}/firstFile.txt)
+configure_file(${CMAKE_CURRENT_LIST_DIR}/FetchGitTags/CMakeLists.txt
+    ${srcDir}/CMakeLists.txt COPYONLY)
+
+function(execGitCommand)
+  execute_process(
+    WORKING_DIRECTORY ${srcRepo}
+    COMMAND ${GIT_EXECUTABLE} ${ARGN}
+    COMMAND_ECHO STDOUT
+    COMMAND_ERROR_IS_FATAL ANY
+  )
+endfunction()
+
+function(configureAndBuild tag)
+  execute_process(COMMAND ${CMAKE_COMMAND}
+      -G ${CMAKE_GENERATOR} -T "${CMAKE_GENERATOR_TOOLSET}"
+      -A "${CMAKE_GENERATOR_PLATFORM}"
+      -D repoDir:PATH=${srcRepo}
+      -D gitTag:STRING=${tag}
+      -B ${binDir}
+      -S ${srcDir}
+    COMMAND_ECHO STDOUT
+    COMMAND_ERROR_IS_FATAL ANY
+  )
+
+  execute_process(COMMAND ${CMAKE_COMMAND} --build ${binDir} --target fetcher
+    WORKING_DIRECTORY ${binDir}
+    COMMAND_ECHO STDOUT
+    COMMAND_ERROR_IS_FATAL ANY
+  )
+endfunction()
+
+# Setup a fresh source repo with a predictable default branch across all
+# git versions
+execGitCommand(-c init.defaultBranch=master init)
+execGitCommand(config --add user.email "testauthor@cmake.org")
+execGitCommand(config --add user.name testauthor)
+
+# Create the initial repo structure
+execGitCommand(add firstFile.txt)
+execGitCommand(commit -m "First file")
+
+message(STATUS "First configure-and-build")
+configureAndBuild(master)
+
+# Create a tagged commit that is not on any branch. With git 2.20 or later,
+# this commit won't be fetched without the --tags option.
+file(TOUCH ${srcRepo}/secondFile.txt)
+execGitCommand(add secondFile.txt)
+execGitCommand(commit -m "Second file")
+execGitCommand(tag -a -m "Adding tag" tag_of_interest)
+execGitCommand(reset --hard HEAD~1)
+
+message(STATUS "Second configure-and-build")
+configureAndBuild(tag_of_interest)
diff --git a/Tests/RunCMake/ExternalProject/FetchGitTags/CMakeLists.txt b/Tests/RunCMake/ExternalProject/FetchGitTags/CMakeLists.txt
new file mode 100644
index 0000000..d9a380c
--- /dev/null
+++ b/Tests/RunCMake/ExternalProject/FetchGitTags/CMakeLists.txt
@@ -0,0 +1,15 @@
+cmake_minimum_required(VERSION 3.19)
+project(FetchTags LANGUAGES NONE)
+
+include(ExternalProject)
+
+# repoDir and gitTag are expected to be set as cache variables
+
+ExternalProject_Add(fetcher
+    GIT_REPOSITORY ${repoDir}
+    GIT_TAG ${gitTag}
+    GIT_REMOTE_UPDATE_STRATEGY CHECKOUT
+    CONFIGURE_COMMAND ""
+    BUILD_COMMAND ""
+    INSTALL_COMMAND ""
+)
diff --git a/Tests/RunCMake/ExternalProject/RunCMakeTest.cmake b/Tests/RunCMake/ExternalProject/RunCMakeTest.cmake
index 22b8d24..976655a 100644
--- a/Tests/RunCMake/ExternalProject/RunCMakeTest.cmake
+++ b/Tests/RunCMake/ExternalProject/RunCMakeTest.cmake
@@ -181,3 +181,12 @@ endfunction()
 if(NOT RunCMake_GENERATOR MATCHES "Visual Studio 9 ")
   __ep_test_CONFIGURE_HANDLED_BY_BUILD()
 endif()
+
+find_package(Git QUIET)
+if(GIT_EXECUTABLE)
+  # Note that there appear to be differences in where git writes its output to
+  # on some platforms. It may go to stdout or stderr, so force it to be merged.
+  set(RunCMake_TEST_OUTPUT_MERGE TRUE)
+  run_cmake(FetchGitTags)
+  set(RunCMake_TEST_OUTPUT_MERGE FALSE)
+endif()