Update CMakeLists.txt

Author: ssh4net

src/imiv/CMakeLists.txt

@@ -595,10 +595,16 @@ if (_imiv_renderer_is_vulkan)
     endif ()
 elseif (_imiv_renderer_is_metal)
     set (_imiv_has_runtime_glslang OFF)
+    record_build_dependency (
+        Vulkan NOTFOUND
+        NOT_FOUND_EXPLANATION
+            "(not required on Metal backend; select OIIO_IMIV_RENDERER=vulkan to check MoltenVK/Vulkan support)")
     record_build_dependency (
         GLSLANG_RUNTIME NOTFOUND
         NOT_FOUND_EXPLANATION
-            "(runtime shader compilation disabled on Metal backend)")
+            "(runtime shader compilation not checked on Metal backend; only required for Vulkan runtime OCIO shaders)")
+    message (STATUS
+             "imiv: skipping Vulkan runtime shader tool discovery on Metal backend")
     find_library (OIIO_IMIV_COCOA_FRAMEWORK Cocoa)
     find_library (OIIO_IMIV_METAL_FRAMEWORK Metal)
     find_library (OIIO_IMIV_QUARTZCORE_FRAMEWORK QuartzCore)
@@ -615,10 +621,16 @@ elseif (_imiv_renderer_is_metal)
           ${OIIO_IMIV_QUARTZCORE_FRAMEWORK})
 elseif (_imiv_renderer_is_opengl)
     set (_imiv_has_runtime_glslang OFF)
+    record_build_dependency (
+        Vulkan NOTFOUND
+        NOT_FOUND_EXPLANATION
+            "(not required on OpenGL backend; select OIIO_IMIV_RENDERER=vulkan to check Vulkan support)")
     record_build_dependency (
         GLSLANG_RUNTIME NOTFOUND
         NOT_FOUND_EXPLANATION
-            "(runtime shader compilation disabled on OpenGL backend)")
+            "(runtime shader compilation not checked on OpenGL backend; only required for Vulkan runtime OCIO shaders)")
+    message (STATUS
+             "imiv: skipping Vulkan runtime shader tool discovery on OpenGL backend")
     find_package (OpenGL QUIET)
     if (TARGET OpenGL::GL)
         list (APPEND _imiv_link_libs OpenGL::GL)
@@ -631,10 +643,16 @@ elseif (_imiv_renderer_is_opengl)
     endif ()
 else ()
     set (_imiv_has_runtime_glslang OFF)
+    record_build_dependency (
+        Vulkan NOTFOUND
+        NOT_FOUND_EXPLANATION
+            "(not required on selected backend)")
     record_build_dependency (
         GLSLANG_RUNTIME NOTFOUND
         NOT_FOUND_EXPLANATION
-            "(runtime shader compilation disabled on selected backend)")
+            "(runtime shader compilation not checked on selected backend)")
+    message (STATUS
+             "imiv: skipping Vulkan runtime shader tool discovery on selected backend")
 endif ()
 
 if (MSVC)