feat(rake): generate compile_commands.json

.gitignore

@@ -59,5 +59,5 @@ _screenshots/
 .gitconfig
 .cache
 
-# Generate by a rake task, try `rake <target>:clangd`
-.clangd
+# Generate by rake
+compile_commands.json

rake/_utils.rb

@@ -141,7 +141,9 @@ def compile_file(src, target)
     cmd += format_includes(target)
     cmd += format_defines(target)
     cmd += get_dependency_flags(src)
-    cmd += ["-o", src_to_obj( src ), src]
+    obj = src_to_obj( src )
+    cmd += ["-MJ", obj.ext("o.json")] # Write a compilation database entry per input, see https://clang.llvm.org/docs/ClangCommandLineReference.html#cmdoption-clang-MJ-arg
+    cmd += ["-o", obj, src]
 
     # Run the command
     sh "#{cmd.join(" ")}", verbose: VERBOSE
@@ -164,29 +166,6 @@ def link_binary( target )
     sh "#{$linker} #{compiler_flags} #{defines} -o #{binary_path} #{objects} #{linker_flags}", verbose: VERBOSE
 end
 
-def get_clangd_yaml(target)
-# Note:
-#   I couln't get the formatting I wanted (no double quotes on strings)
-#   That's why I do manually, but it is simple.
-#
-# Format documentation: https://clangd.llvm.org/config#compileflags
-#
-    cmd = get_compile_file_command("fake.cpp", target)
-    flags = cmd.split(" ") # remove program name
-
-    result = "#
-# .clang file generated for target #{target.name}, #{DateTime.now}
-# !This file has been generated by nodable's rake script
-# Do not modify it manually, edit _utils.rb instead!
-#
-CompileFlags:
-  Add: [#{flags.join(",")}]
-  Compiler: #{$cxx_compiler}
-
-"
-    result    
-end
-
 def format_defines(target)
     target.defines.map{|d| "-D\"#{d}\"" }
 end
@@ -236,6 +215,29 @@ def copy_asset(source, destination)
     puts "  Copy asset: #{source} => #{destination}"
 end
 
+def update_compile_commands_json()
+    # Generate compile_commands.json for clangd
+    output_file = "./compile_commands.json"
+
+    # clear existing file
+    if File.exist? output_file
+        FileUtils.rm_f output_file
+    end
+
+    # Grab all *.o.json files from object dir
+    command_files = FileList["#{OBJ_DIR}/**/*.json"]
+
+    # combine
+    commands = command_files.map{|f| File.read(f)}.join()
+    content = "[" + commands[0...-2] + "]" # -2: remove trailing comma
+    File.write( output_file, content)
+
+    # debug log
+    if VERBOSE 
+        puts content
+    end
+end
+
 def tasks_for_target(target)
 
     objects = get_self_objects(target)
@@ -291,7 +293,9 @@ def tasks_for_target(target)
             puts "#{target.name} | Linking '#{get_binary_path(target)}' DONE"
         end
 
-        multitask :compile_objects => objects_with_deps
+        multitask :compile_objects => objects_with_deps do
+            update_compile_commands_json()
+        end
 
         desc "Run #{target.name}"
         task :run => :build do
@@ -312,33 +316,4 @@ def tasks_for_target(target)
             compile_file( src, target)
         end
     end
-
-    # Return the command to compile a given file
-    #
-    #   File don't need to exists since nothing run,
-    #   we simplify build the command as string and return it via stdout.
-    #
-    task :compile_command, [:filename] do |t, args|
-        filename = args[:filename] || "file.cpp"
-        puts get_compile_file_command( filename, target)
-    end
-
-    # Generates a clangd yaml file from target
-    #   Save it as .clangd to enable clangd to analyze your code.
-    task :clangd do
-
-        file_path = ".clangd"
-        puts "Generating #{file_path} yaml file ..."
-
-        data = get_clangd_yaml(target)
-
-        if ( File.exists?(file_path))
-            puts "  #{file_path} already exists, removing existing file"
-            File.delete(file_path)
-        end
-        puts "  writing #{file_path} ..."
-        File.write(file_path, data)
-        puts "  #{file_path} updated with the following data:"
-        puts data
-    end
 end