CMakePackageConfigHelpers: Add ARCH_INDEPENDENT option

Allow skipping the architecture check in the package version file generated from calling
write_basic_package_version_file. Document said architecture check.

Fixes: #16184

2 files changed, 64 insertions, 0 deletions

diff --git a/Tests/RunCMake/WriteBasicConfigVersionFile/ArchIndependent.cmake b/Tests/RunCMake/WriteBasicConfigVersionFile/ArchIndependent.cmake
new file mode 100644
index 0000000..13ec5d1
--- /dev/null
+++ b/Tests/RunCMake/WriteBasicConfigVersionFile/ArchIndependent.cmake
@@ -0,0 +1,63 @@
+# Hard-code architecture for test without a real compiler.
+set(CMAKE_SIZEOF_VOID_P 4)
+
+include(WriteBasicConfigVersionFile)
+
+set(_dummy_version 1.0.0)
+
+set(_compatibilities AnyNewerVersion
+                     SameMajorVersion
+                     SameMinorVersion
+                     ExactVersion)
+
+function(test_write_basic_config_version_file_arch_prepare filename_out compat arch_independent arch)
+  if(arch_independent)
+    set(arch_arg ARCH_INDEPENDENT)
+  else()
+    set(arch_arg )
+  endif()
+
+  set(filename "${CMAKE_CURRENT_BINARY_DIR}/${compat}Arch${arch_arg}ConfigVersion.cmake")
+
+  set(CMAKE_SIZEOF_VOID_P "${arch}")
+
+  write_basic_config_version_file("${filename}"
+                                  VERSION "${_dummy_version}"
+                                  COMPATIBILITY "${compat}"
+                                  ${arch_arg})
+
+  set("${filename_out}" "${filename}" PARENT_SCOPE)
+endfunction()
+
+function(test_write_basic_config_version_file_arch_check unsuitable_out filename arch)
+  set(CMAKE_SIZEOF_VOID_P "${arch}")
+  set(PACKAGE_FIND_VERSION "${_dummy_version}")
+
+  include("${filename}")
+
+  set("${unsuitable_out}" "${PACKAGE_VERSION_UNSUITABLE}" PARENT_SCOPE)
+endfunction()
+
+function(test_write_basic_config_version_file_arch_test expected_unsuitable compat arch_independent source_arch user_arch)
+  test_write_basic_config_version_file_arch_prepare(filename "${compat}" "${arch_independent}" "${source_arch}")
+  test_write_basic_config_version_file_arch_check(unsuitable "${filename}" "${user_arch}")
+  if(unsuitable AND NOT expected_unsuitable)
+    message(SEND_ERROR "Architecture was checked when it shouldn't have been. Compatibility: ${compat} ARCH_INDEPENDENT: ${arch_independent}.")
+  elseif(expected_unsuitable AND NOT unsuitable)
+    message(SEND_ERROR "Requested architecture check not performed. Compatibility: ${compat} ARCH_INDEPENDENT: ${arch_independent}.")
+  endif()
+endfunction()
+
+set(_unsuitable TRUE)
+set(_suitable FALSE)
+
+foreach(compat ${_compatibilities})
+  test_write_basic_config_version_file_arch_test("${_suitable}" "${compat}" TRUE 4 4)
+  test_write_basic_config_version_file_arch_test("${_suitable}" "${compat}" FALSE 4 4)
+  test_write_basic_config_version_file_arch_test("${_suitable}" "${compat}" TRUE 4 8)
+  test_write_basic_config_version_file_arch_test("${_unsuitable}" "${compat}" FALSE 4 8)
+  test_write_basic_config_version_file_arch_test("${_suitable}" "${compat}" TRUE 8 4)
+  test_write_basic_config_version_file_arch_test("${_unsuitable}" "${compat}" FALSE 8 4)
+  test_write_basic_config_version_file_arch_test("${_suitable}" "${compat}" TRUE 8 8)
+  test_write_basic_config_version_file_arch_test("${_suitable}" "${compat}" FALSE 8 8)
+endforeach()
diff --git a/Tests/RunCMake/WriteBasicConfigVersionFile/RunCMakeTest.cmake b/Tests/RunCMake/WriteBasicConfigVersionFile/RunCMakeTest.cmake
index e956f4f..5db33f7 100644
--- a/Tests/RunCMake/WriteBasicConfigVersionFile/RunCMakeTest.cmake
+++ b/Tests/RunCMake/WriteBasicConfigVersionFile/RunCMakeTest.cmake
@@ -1,3 +1,4 @@
 include(RunCMake)
 
 run_cmake(All)
+run_cmake(ArchIndependent)