From 6ee9ba2334dc81ead64ad1393b501c7cbe945a0f Mon Sep 17 00:00:00 2001
From: Ian-Woo Kim <ianwookim@gmail.com>
Date: Thu, 21 Sep 2023 14:58:53 -0700
Subject: [PATCH] error code and message callback. exit when error happens.

---
 daemon/app/ghc-specter-daemon/Util/GUI.hs | 46 ++++++++++++-----------
 1 file changed, 25 insertions(+), 21 deletions(-)

diff --git a/daemon/app/ghc-specter-daemon/Util/GUI.hs b/daemon/app/ghc-specter-daemon/Util/GUI.hs
index ffb22c38..b53c33e6 100644
--- a/daemon/app/ghc-specter-daemon/Util/GUI.hs
+++ b/daemon/app/ghc-specter-daemon/Util/GUI.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE ForeignFunctionInterface #-}
 {-# LANGUAGE OverloadedStrings #-}
 
 module Util.GUI
@@ -30,11 +31,11 @@ import Data.String (fromString)
 import Data.Text (Text)
 import Data.Text qualified as T
 import FFICXX.Runtime.Cast (FPtr (..))
-import Foreign.C.String (CString)
-import Foreign.C.Types (CInt)
+import Foreign.C.String (CString, peekCString)
+import Foreign.C.Types (CInt (..))
 import Foreign.Marshal.Alloc (alloca)
 import Foreign.Marshal.Utils (fromBool, toBool)
-import Foreign.Ptr (nullPtr)
+import Foreign.Ptr (FunPtr, nullPtr)
 import Foreign.Storable (peek)
 import ImGui
 import ImGui.Enum
@@ -46,28 +47,41 @@ import ImGui.ImGuiIO.Implementation
 import ImGui.ImVec2.Implementation (imVec2_x_get, imVec2_y_get)
 -- import ImPlot qualified
 import STD.Deletable (delete)
+import System.Exit (exitFailure)
 import Text.Printf (printf)
 import Util.Orphans ()
 
+type GLFWerrorfun = CInt -> CString -> IO ()
+
+foreign import ccall "wrapper"
+  makeFunPtr :: GLFWerrorfun -> IO (FunPtr GLFWerrorfun)
+
+foreign import ccall safe "glfwSetErrorCallback"
+  c_glfwSetErrorCallback :: FunPtr GLFWerrorfun -> IO (FunPtr GLFWerrorfun)
+
+printError :: CInt -> CString -> IO ()
+printError err_code cstr = do
+  putStrLn ("Error Code : " <> show err_code)
+  str <- peekCString cstr
+  putStrLn ("Error: " <> str)
+
 initialize :: String -> IO (ImGuiContext, ImGuiIO, GLFWwindow)
 initialize title = do
+  fun_ptr <- makeFunPtr printError
+  _ <- c_glfwSetErrorCallback fun_ptr
+
   let glsl_version :: CString
       glsl_version = "#version 150"
-  putStrLn "init1"
   successCode <- glfwInit
   if successCode /= 0
     then putStrLn "GLFW is initialized"
-    else putStrLn "GLFW is not initialized"
+    else putStrLn "GLFW is not initialized" >> exitFailure
   glfwWindowHint (0x22002 {- GLFW_CONTEXT_VERSION_MAJOR -}) 3
-  putStrLn "init3"
   glfwWindowHint (0x22003 {- GLFW_CONTEXT_VERSION_MINOR -}) 2
-  putStrLn "init4"
   -- 3.2+ only
   glfwWindowHint (0x22008 {- GLFW_OPENGL_PROFILE -}) (0x32001 {- GLFW_OPENGL_CORE_PROFILE -})
-  putStrLn "init5"
   -- Required on Mac
   glfwWindowHint (0x22006 {- GLFW_OPENGL_FORWARD_COMPAT -}) (1 {- GL_TRUE -})
-  putStrLn "init6"
   window :: GLFWwindow <-
     glfwCreateWindow
       1280
@@ -76,35 +90,25 @@ initialize title = do
       (cast_fptr_to_obj nullPtr :: GLFWmonitor)
       (cast_fptr_to_obj nullPtr :: GLFWwindow)
   if get_fptr window == nullPtr
-    then putStrLn "Cannot create window"
+    then putStrLn "Cannot create window" >> exitFailure
     else putStrLn "Successful window creation"
-  putStrLn $ "init7: " ++ show window
   glfwMakeContextCurrent window
-  putStrLn "init8"
   -- Enable vsync
   glfwSwapInterval 1
-  putStrLn "init9"
   ctxt <- createContext
-  putStrLn "init10"
   -- ImPlot.createImPlotContext
 
   -- Setup Dear ImGui style
   -- styleColorsDark
   styleColorsLight
-  putStrLn "init11"
 
   -- Setup Platform/Renderer backends
-  b <- imGui_ImplGlfw_InitForOpenGL window (fromBool True)
-  putStrLn ("after InitForOpenGL: " <> show b)
-  putStrLn "init12"
+  _b <- imGui_ImplGlfw_InitForOpenGL window (fromBool True)
   _ <- imGui_ImplOpenGL3_Init glsl_version
-  putStrLn "init13"
 
   -- Enable Keyboard Controls and Gamepad Controls
   io <- getIO
-  putStrLn "init14"
   flags <- imGuiIO_ConfigFlags_get io
-  putStrLn "init15"
   let flags' =
         flags
           .|. fromIntegral (fromEnum ImGuiConfigFlags_NavEnableKeyboard)