FetchContent: Invoke steps directly and avoid a separate sub-build

The cost of setting up and executing a separate sub-build to do the
download, update and patch steps required for FetchContent population
can be significant with some platforms and CMake generators. Avoid the
sub-build altogether by invoking the step scripts directly.

Previously, if no generator was set (e.g. population was being done in
script mode), a generator needed to be available on the default PATH.
Since we no longer use a sub-build, this restriction is also now gone.

Fixes: #21703

1 files changed, 30 insertions, 17 deletions

diff --git a/Modules/ExternalProject/hgclone.cmake.in b/Modules/ExternalProject/hgclone.cmake.in
index 09395cc..5561955 100644
--- a/Modules/ExternalProject/hgclone.cmake.in
+++ b/Modules/ExternalProject/hgclone.cmake.in
@@ -3,43 +3,56 @@
 
 cmake_minimum_required(VERSION 3.5)
 
+set(quiet "@quiet@")
+set(script_dir "@CMAKE_CURRENT_FUNCTION_LIST_DIR@/ExternalProject")
+include(${script_dir}/captured_process_setup.cmake)
+
 if(NOT "@hgclone_infofile@" IS_NEWER_THAN "@hgclone_stampfile@")
-  message(STATUS "Avoiding repeated hg clone, stamp file is up to date: '@hgclone_stampfile@'")
+  if(NOT quiet)
+    message(STATUS
+      "Avoiding repeated hg clone, stamp file is up to date: "
+      "'@hgclone_stampfile@'"
+    )
+  endif()
   return()
 endif()
 
 execute_process(
   COMMAND ${CMAKE_COMMAND} -E rm -rf "@source_dir@"
   RESULT_VARIABLE error_code
-  )
-if(error_code)
-  message(FATAL_ERROR "Failed to remove directory: '@source_dir@'")
-endif()
+  ${capture_output}
+)
+_ep_command_check_result(
+  error_code "Failed to remove directory: '@source_dir@'"
+)
 
 execute_process(
   COMMAND "@hg_EXECUTABLE@" clone -U "@hg_repository@" "@src_name@"
   WORKING_DIRECTORY "@work_dir@"
   RESULT_VARIABLE error_code
-  )
-if(error_code)
-  message(FATAL_ERROR "Failed to clone repository: '@hg_repository@'")
-endif()
+  ${capture_output}
+)
+_ep_command_check_result(
+  error_code "Failed to clone repository: '@hg_repository@'"
+)
 
 execute_process(
   COMMAND "@hg_EXECUTABLE@" update @hg_tag@
   WORKING_DIRECTORY "@work_dir@/@src_name@"
   RESULT_VARIABLE error_code
-  )
-if(error_code)
-  message(FATAL_ERROR "Failed to checkout tag: '@hg_tag@'")
-endif()
+  ${capture_output}
+)
+_ep_command_check_result(
+  error_code "Failed to checkout tag: '@hg_tag@'"
+)
 
 # Complete success, update the script-last-run stamp file:
 #
 execute_process(
   COMMAND ${CMAKE_COMMAND} -E copy "@hgclone_infofile@" "@hgclone_stampfile@"
   RESULT_VARIABLE error_code
-  )
-if(error_code)
-  message(FATAL_ERROR "Failed to copy script-last-run stamp file: '@hgclone_stampfile@'")
-endif()
+  ${capture_output}
+)
+_ep_command_check_result(
+  error_code "Failed to copy script-last-run stamp file: '@hgclone_stampfile@'"
+)