[clangd] Fix find_program() result check when searching for gRPC

[ArcsinX]

Summary

find_program(<VAR> ...) sets <VAR> to <VAR>-NOTFOUND if nothing was found.
So we need to compare <VAR> with "<VAR>-NOTFOUND" or just use if([NOT] <VAR>), because if(<VAR>) is false if <VAR> ends in the suffix -NOTFOUND.

[kbobyrev]

Ah, good catch, thank you! Alternatively there seems to be Package_FOUND variable but what your propose is cleaner.

Do you want me to land the patch for you?

[ArcsinX]

In D85958#2217681, @kbobyrev wrote:

Do you want me to land the patch for you?

I already have commit access, thank you.

[ArcsinX]

Rebase

llvm/cmake/modules/FindGRPC.cmake

else()
   # We always link dynamically in this mode. While the static libraries are
   # usually installed, the CMake files telling us *which* static libraries to
   # link are not.
   if (NOT BUILD_SHARED_LIBS)
     message(NOTICE "gRPC and Protobuf will be linked dynamically. If you want static linking, build gRPC from sources.")
   endif()
   find_program(GRPC_CPP_PLUGIN grpc_cpp_plugin)
   find_program(PROTOC protoc)
-  if (GRPC_CPP_PLUGIN-NOTFOUND OR PROTOC-NOTFOUND)
+  if (NOT GRPC_CPP_PLUGIN OR NOT PROTOC)
     message(FATAL_ERROR "gRPC C++ Plugin and Protoc must be on $PATH for Clangd remote index build.")
   endif()
   # On macOS the libraries are typically installed via Homebrew and are not on
   # the system path.
   if (${APPLE})
     find_program(HOMEBREW brew)
     # If Homebrew is not found, the user might have installed libraries
     # manually. Fall back to the system path.
-    if (NOT HOMEBREW-NOTFOUND)
+    if (HOMEBREW)
       execute_process(COMMAND ${HOMEBREW} --prefix grpc
         OUTPUT_VARIABLE GRPC_HOMEBREW_PATH
         RESULT_VARIABLE GRPC_HOMEBREW_RETURN_CODE
         OUTPUT_STRIP_TRAILING_WHITESPACE)
       execute_process(COMMAND ${HOMEBREW} --prefix protobuf
         OUTPUT_VARIABLE PROTOBUF_HOMEBREW_PATH
         RESULT_VARIABLE PROTOBUF_HOMEBREW_RETURN_CODE
         OUTPUT_STRIP_TRAILING_WHITESPACE)