From 5f3f995fde85d0c8008abff9f2c89ad25b031b9c Mon Sep 17 00:00:00 2001
From: Moritz Bunkus <moritz@bunkus.org>
Date: Tue, 27 Feb 2018 20:42:01 +0100
Subject: [PATCH] build system: add accidentally ignored
 compilation_database.rb

---
 .gitignore                     |  1 -
 rake.d/compilation_database.rb | 36 ++++++++++++++++++++++++++++++++++
 2 files changed, 36 insertions(+), 1 deletion(-)
 create mode 100644 rake.d/compilation_database.rb

diff --git a/.gitignore b/.gitignore
index 1ad18b91a..c872f3266 100644
--- a/.gitignore
+++ b/.gitignore
@@ -50,7 +50,6 @@
 /po/*.mo
 /po/mkvtoolnix.pot
 /po/qt/*.qm
-/rake.d/compilation_database.rb
 /rake.d/dependency.d
 /share/icons/*/*.h
 /src/*/qt_resources.cpp
diff --git a/rake.d/compilation_database.rb b/rake.d/compilation_database.rb
new file mode 100644
index 000000000..67f05b143
--- /dev/null
+++ b/rake.d/compilation_database.rb
@@ -0,0 +1,36 @@
+module Mtx
+  module CompilationDatabase
+    @file_name            = "#{$build_dir}/compile_commands.json"
+    @compilation_commands = {}
+
+    def self.database_file_name
+      @file_name
+    end
+
+    def self.read
+      return {} unless FileTest.exists?(@file_name)
+
+      Hash[
+        *JSON.parse(IO.readlines(@file_name).join("")).
+          map { |entry| [ entry["file"], entry ] }.
+          flatten
+      ]
+    end
+
+    def self.write
+      return if @compilation_commands.empty?
+      return if !FileTest.exists?(@file_name) && !c?(:BUILD_COMPILATION_DATABASE)
+
+      entries = self.read.merge(@compilation_commands).values.sort_by { |e| e["file"] }
+      File.open(@file_name, "w") do |f|
+        f.write(JSON.generate(entries, :indent => "  ", :object_nl => "\n", :array_nl => "\n"))
+      end
+    end
+
+    def self.add entry
+      @compilation_commands[entry["file"]] = entry
+    end
+  end
+end
+
+at_exit { Mtx::CompilationDatabase.write }