From 86032ae0ebb7e86f3ff5617e080dd827dbbe98b0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Gae=CC=88tan=20Lehmann?= <gaetan.lehmann@gmail.com>
Date: Fri, 6 Mar 2015 11:43:16 +0100
Subject: [PATCH] ExternalProject: Replace placeholder tokens in BYPRODUCTS

This allows the developer to specify the byproducts relative to the
binary directory without the need to set the binary directory location
explicitly.
---
 .../dev/ExternalProject-byproducts-tokens.rst |  5 +++++
 Modules/ExternalProject.cmake                 |  6 +++---
 Tests/CustomCommandByproducts/CMakeLists.txt  | 21 +++++++++++++++++++
 3 files changed, 29 insertions(+), 3 deletions(-)
 create mode 100644 Help/release/dev/ExternalProject-byproducts-tokens.rst

diff --git a/Help/release/dev/ExternalProject-byproducts-tokens.rst b/Help/release/dev/ExternalProject-byproducts-tokens.rst
new file mode 100644
index 000000000..20b4dd468
--- /dev/null
+++ b/Help/release/dev/ExternalProject-byproducts-tokens.rst
@@ -0,0 +1,5 @@
+ExternalProject-byproducts-tokens
+---------------------------------
+
+* The :module:`ExternalProject` module learned to replace tokens
+  like ``<BINARY_DIR>`` in the ``BYPRODUCTS`` of each step.
diff --git a/Modules/ExternalProject.cmake b/Modules/ExternalProject.cmake
index 1f9f4d3e8..d7b985de9 100644
--- a/Modules/ExternalProject.cmake
+++ b/Modules/ExternalProject.cmake
@@ -251,8 +251,8 @@ Create custom targets to build projects in external trees
   ``LOG 1``
     Wrap step in script to log output
 
-  The command line, comment, and working directory of every standard and
-  custom step is processed to replace tokens ``<SOURCE_DIR>``,
+  The command line, comment, working directory, and byproducts of every
+  standard and custom step are processed to replace tokens ``<SOURCE_DIR>``,
   ``<BINARY_DIR>``, ``<INSTALL_DIR>``, and ``<TMP_DIR>`` with
   corresponding property values.
 
@@ -1443,7 +1443,7 @@ function(ExternalProject_Add_Step name step)
   endif()
 
   # Replace location tags.
-  _ep_replace_location_tags(${name} comment command work_dir)
+  _ep_replace_location_tags(${name} comment command work_dir byproducts)
 
   # Custom comment?
   get_property(comment_set TARGET ${name} PROPERTY _EP_${step}_COMMENT SET)
diff --git a/Tests/CustomCommandByproducts/CMakeLists.txt b/Tests/CustomCommandByproducts/CMakeLists.txt
index 884f8c231..3289e8f9f 100644
--- a/Tests/CustomCommandByproducts/CMakeLists.txt
+++ b/Tests/CustomCommandByproducts/CMakeLists.txt
@@ -102,6 +102,27 @@ add_library(ExternalLibrary STATIC IMPORTED)
 set_property(TARGET ExternalLibrary PROPERTY IMPORTED_LOCATION ${ExternalLibrary_LIBRARY})
 add_dependencies(ExternalLibrary ExternalTarget)
 
+# Generate the library file of an imported target as a byproduct
+# of an external project. The byproduct uses <BINARY_DIR> that is substituted
+# by the real binary path
+if(CMAKE_CONFIGURATION_TYPES)
+  set(cfg /${CMAKE_CFG_INTDIR})
+else()
+  set(cfg)
+endif()
+include(ExternalProject)
+ExternalProject_Add(ExtTargetSubst
+  SOURCE_DIR "${CMAKE_CURRENT_SOURCE_DIR}/External"
+  DOWNLOAD_COMMAND ""
+  INSTALL_COMMAND ""
+  BUILD_BYPRODUCTS "<BINARY_DIR>${cfg}/${CMAKE_STATIC_LIBRARY_PREFIX}ExternalLibrary${CMAKE_STATIC_LIBRARY_SUFFIX}"
+  )
+ExternalProject_Get_Property(ExtTargetSubst binary_dir)
+add_library(ExternalLibraryWithSubstitution STATIC IMPORTED)
+set_property(TARGET ExternalLibraryWithSubstitution PROPERTY IMPORTED_LOCATION
+  ${binary_dir}${cfg}/${CMAKE_STATIC_LIBRARY_PREFIX}ExternalLibrary${CMAKE_STATIC_LIBRARY_SUFFIX})
+add_dependencies(ExternalLibraryWithSubstitution ExtTargetSubst)
+
 # Add an executable consuming all the byproducts.
 add_executable(CustomCommandByproducts
   CustomCommandByproducts.c