Define LINK_DEPENDS target property (#11406)

Custom Makefile link rules may need to depend on linker scripts.  Define
this property to allow user-specified link-time dependencies.

3 files changed, 32 insertions, 0 deletions

diff --git a/Tests/BuildDepends/CMakeLists.txt b/Tests/BuildDepends/CMakeLists.txt
index 8714640..31392b5 100644
--- a/Tests/BuildDepends/CMakeLists.txt
+++ b/Tests/BuildDepends/CMakeLists.txt
@@ -34,6 +34,12 @@ if(WIN32 AND "${CMAKE_CXX_COMPILER_ID}" MATCHES "Intel")
   set(_cmake_options "-DCMAKE_EXE_LINKER_FLAGS=")
 endif()
 
+if("${CMAKE_GENERATOR}" MATCHES "Make")
+  set(TEST_LINK_DEPENDS ${BuildDepends_BINARY_DIR}/Project/linkdep.txt)
+  file(WRITE ${TEST_LINK_DEPENDS} "1")
+endif()
+list(APPEND _cmake_options "-DTEST_LINK_DEPENDS=${TEST_LINK_DEPENDS}")
+
 file(MAKE_DIRECTORY ${BuildDepends_BINARY_DIR}/Project)
 message("Creating Project/foo.cxx")
 write_file(${BuildDepends_BINARY_DIR}/Project/foo.cxx 
@@ -131,6 +137,10 @@ file(WRITE ${BuildDepends_BINARY_DIR}/Project/zot_macro_dir.hxx
 file(WRITE ${BuildDepends_BINARY_DIR}/Project/zot_macro_tgt.hxx
   "static const char* zot_macro_tgt = \"zot_macro_tgt changed\";\n")
 
+if(TEST_LINK_DEPENDS)
+  file(WRITE ${TEST_LINK_DEPENDS} "2")
+endif()
+
 help_xcode_depends()
 
 message("Building project second time")
@@ -194,3 +204,16 @@ if("${out}" STREQUAL "${VALUE_CHANGED}")
 else("${out}" STREQUAL "${VALUE_CHANGED}")
   message(SEND_ERROR "Project did not rebuild properly!")
 endif("${out}" STREQUAL "${VALUE_CHANGED}")
+
+if(TEST_LINK_DEPENDS)
+  set(linkdep ${BuildDepends_BINARY_DIR}/Project/linkdep${CMAKE_EXECUTABLE_SUFFIX})
+  if(${linkdep} IS_NEWER_THAN ${TEST_LINK_DEPENDS})
+    message("LINK_DEPENDS worked")
+  else()
+    message(SEND_ERROR "LINK_DEPENDS failed.  Executable
+  ${linkdep}
+is not newer than dependency
+  ${TEST_LINK_DEPENDS}
+")
+  endif()
+endif()
diff --git a/Tests/BuildDepends/Project/CMakeLists.txt b/Tests/BuildDepends/Project/CMakeLists.txt
index e9d1296..70a2f37 100644
--- a/Tests/BuildDepends/Project/CMakeLists.txt
+++ b/Tests/BuildDepends/Project/CMakeLists.txt
@@ -80,3 +80,8 @@ set_property(
   DIRECTORY
   PROPERTY IMPLICIT_DEPENDS_INCLUDE_TRANSFORM "ZOT_DIR(%)=<zot_%_dir.hxx>"
   )
+
+if(TEST_LINK_DEPENDS)
+  add_executable(linkdep linkdep.cxx)
+  set_property(TARGET linkdep PROPERTY LINK_DEPENDS ${TEST_LINK_DEPENDS})
+endif()
diff --git a/Tests/BuildDepends/Project/linkdep.cxx b/Tests/BuildDepends/Project/linkdep.cxx
new file mode 100644
index 0000000..f8b643a
--- /dev/null
+++ b/Tests/BuildDepends/Project/linkdep.cxx
@@ -0,0 +1,4 @@
+int main()
+{
+  return 0;
+}