Merge pull request KhronosGroup#285 from jeremy-lunarg/hayes-fix-271

Remove custom target if skipping install

Author: johnkslang

CMakeLists.txt

@@ -44,11 +44,6 @@ project(SPIRV-Headers VERSION 1.5.5)
 #   2. cmake ..
 #   3. cmake --build . --target install
 
-# legacy
-add_custom_target(install-headers
-    COMMAND cmake -E copy_directory ${CMAKE_CURRENT_SOURCE_DIR}/include/spirv
-        $ENV{DESTDIR}${CMAKE_INSTALL_PREFIX}/include/spirv)
-
 option(SPIRV_HEADERS_SKIP_EXAMPLES "Skip building examples"
       ${SPIRV_HEADERS_SKIP_EXAMPLES})
 
@@ -61,6 +56,10 @@ endif()
 
 if(NOT ${SPIRV_HEADERS_SKIP_INSTALL})
   set(SPIRV_HEADERS_ENABLE_INSTALL ON)
+  # legacy
+  add_custom_target(install-headers
+      COMMAND cmake -E copy_directory ${CMAKE_CURRENT_SOURCE_DIR}/include/spirv
+          $ENV{DESTDIR}${CMAKE_INSTALL_PREFIX}/include/spirv)
 endif()
 
 if (SPIRV_HEADERS_ENABLE_EXAMPLES)