commit a6d3fee77cb526457ab3c5d427f93530f7621b2b
author Brad King <brad.king@kitware.com> Fri Mar 01 07:54:17 2019 -0500
committer Brad King <brad.king@kitware.com> Fri Mar 01 07:54:17 2019 -0500
tree db0bc503c8bca613d3cc0079ec5c26ab923fcfa7
parent e6897c72e7c59f7a0b82ed19c1bdb40d42f7adaa

ExternalProject: Restore default log dir with custom stamp dir

In commit b6f6cac378 (ExternalProject: add LOG_DIR option that allows
overriding of log location, 2018-10-12, v3.14.0-rc1~515^2~1) the log
directory got its own option.  The intention was to fall back to the
stamp directory by default.  However, the implementation actually only
falls back to the same default as the stamp directory and does not
consider a custom stamp dir.

Update the default log dir computation to fall back to whatever is the
final selection for the stamp dir.

Fixes: #19000

Modules/ExternalProject.cmake

diff --git a/Modules/ExternalProject.cmake b/Modules/ExternalProject.cmake
index c5d6b45..8c943c5 100644
--- a/Modules/ExternalProject.cmake
+++ b/Modules/ExternalProject.cmake
@@ -1643,7 +1643,6 @@
     set(stamp_default "${base}/Stamp/${name}")
     set(install_default "${base}/Install/${name}")
   endif()
-  set(log_default "${stamp_default}")
   get_property(build_in_source TARGET ${name} PROPERTY _EP_BUILD_IN_SOURCE)
   if(build_in_source)
     get_property(have_binary_dir TARGET ${name} PROPERTY _EP_BINARY_DIR SET)
@@ -1653,7 +1652,9 @@
     endif()
   endif()
   set(top "${CMAKE_CURRENT_BINARY_DIR}")
-  set(places stamp download source binary install tmp log)
+
+  # Apply defaults and convert to absolute paths.
+  set(places stamp download source binary install tmp)
   foreach(var ${places})
     string(TOUPPER "${var}" VAR)
     get_property(${var}_dir TARGET ${name} PROPERTY _EP_${VAR}_DIR)
@@ -1665,6 +1666,17 @@
     endif()
     set_property(TARGET ${name} PROPERTY _EP_${VAR}_DIR "${${var}_dir}")
   endforeach()
+
+  # Special case for default log directory based on stamp directory.
+  get_property(log_dir TARGET ${name} PROPERTY _EP_LOG_DIR)
+  if(NOT log_dir)
+    get_property(log_dir TARGET ${name} PROPERTY _EP_STAMP_DIR)
+  endif()
+  if(NOT IS_ABSOLUTE "${log_dir}")
+    get_filename_component(log_dir "${top}/${log_dir}" ABSOLUTE)
+  endif()
+  set_property(TARGET ${name} PROPERTY _EP_LOG_DIR "${log_dir}")
+
   get_property(source_subdir TARGET ${name} PROPERTY _EP_SOURCE_SUBDIR)
   if(NOT source_subdir)
     set_property(TARGET ${name} PROPERTY _EP_SOURCE_SUBDIR "")