compiler warnings are errors (#1870)

CMakeLists.txt

@@ -30,7 +30,6 @@ endif()
 add_compile_definitions("MLX_VERSION=${MLX_VERSION}")
 
 # --------------------- Processor tests -------------------------
-
 message(
   STATUS
     "Building MLX for ${CMAKE_SYSTEM_PROCESSOR} processor on ${CMAKE_SYSTEM_NAME}"
@@ -64,6 +63,7 @@ include(FetchContent)
 cmake_policy(SET CMP0135 NEW)
 
 add_library(mlx)
+set_target_properties(mlx PROPERTIES COMPILE_WARNING_AS_ERROR ON)
 
 if(MLX_BUILD_METAL)
   set(METAL_LIB "-framework Metal")

mlx/backend/cpu/gemms/bnns.cpp

@@ -43,6 +43,8 @@ void matmul_bnns(
 
   BNNSDataType bnns_dtype = to_bnns_dtype(out.dtype());
 
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
   const BNNSLayerParametersBroadcastMatMul gemm_params{
       /* float alpha = */ alpha,
       /* float beta = */ beta,
@@ -124,6 +126,7 @@ void matmul_bnns(
   }
 
   BNNSFilterDestroy(bnns_filter);
+#pragma GCC diagnostic pop
 }
 
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