Fix issue with ggml-metal.metal path. Closes #1769

[abetlen]

Solution for #1769 issue locating ggml-metal.metal file when building llama.cpp as a shared library. This is the solution proposed by @j-f1 and @swittk all credit to them for this. I've tested and this works for the shared library as well as make and cmake builds of llama.cpp on an M1 Mac with Metal support enabled.

[abetlen]

Just realized this may cause issues with the flake.nix subsitution here, not familiar enough with this though, appreciate any suggestions.

[swittk]

Looks like it's just a simple string substitution to an NSString, so I think maybe we could just replace the line to

                --replace '[bundle pathForResource:@"ggml-metal" ofType:@"metal"];' "@\"$out/ggml-metal.metal\";"

[yagil]

Hi @abetlen, I'm getting this cmake error on my setup (following https://github.com/ggerganov/llama.cpp#metal-build). Happens on a freshly cloned repo as well. FYI.

$ cmake -DLLAMA_METAL=ON ..
# ... other output ...
CMake Error at CMakeLists.txt:222 (set_target_properties):
  set_target_properties Can not find target to add properties to: llama

Edit: don't know if this is bulletproof, but this seems to fix it for me:

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 84e2a88..5ccc32a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -216,12 +216,6 @@ if (LLAMA_METAL)
     # get full path to the file
     #add_compile_definitions(GGML_METAL_DIR_KERNELS="${CMAKE_CURRENT_SOURCE_DIR}/")
 
-    # copy ggml-metal.metal to bin directory
-    configure_file(ggml-metal.metal bin/ggml-metal.metal COPYONLY)
-    if (LLAMA_METAL)
-        set_target_properties(llama PROPERTIES RESOURCE "${CMAKE_CURRENT_SOURCE_DIR}/ggml-metal.metal")
-    endif()
-
     set(LLAMA_EXTRA_LIBS ${LLAMA_EXTRA_LIBS}
         ${FOUNDATION_LIBRARY}
         ${METAL_FRAMEWORK}
@@ -425,6 +419,13 @@ add_library(llama
             llama-util.h
             )
 
+
+# copy ggml-metal.metal to bin directory
+if (LLAMA_METAL)
+    configure_file(ggml-metal.metal bin/ggml-metal.metal COPYONLY)
+    set_target_properties(llama PROPERTIES RESOURCE "${CMAKE_CURRENT_SOURCE_DIR}/ggml-metal.metal")
+endif()
+
 target_include_directories(llama PUBLIC .)
 target_compile_features(llama PUBLIC cxx_std_11) # don't bump
 target_link_libraries(llama PRIVATE

[abetlen]

@yagil yes that's my bad, see #1791

Should be fixed shortly. Also you don't need to remove the configure_file or add anything, just removing the if (LLAMA_METAL) ... set_target_properties block should be sufficient to fix the issue.