From 64e960aa22d2bdc1a6d589b344010408c7cc735c Mon Sep 17 00:00:00 2001
From: Stanislaw Halik <sthalik@misaki.pl>
Date: Sat, 8 Dec 2018 01:29:14 +0100
Subject: [PATCH] enable win32 debug console when launching from console

---
 components/CMakeLists.txt      |  2 +-
 components/debug/debugging.cpp |  5 +++
 components/debug/debugging.hpp |  3 ++
 components/debug/win32.cpp     | 56 ++++++++++++++++++++++++++++++++++
 components/debug/win32.hpp     |  5 +++
 5 files changed, 70 insertions(+), 1 deletion(-)
 create mode 100644 components/debug/win32.cpp
 create mode 100644 components/debug/win32.hpp

diff --git a/components/CMakeLists.txt b/components/CMakeLists.txt
index 7a88dc18e..e34a95396 100644
--- a/components/CMakeLists.txt
+++ b/components/CMakeLists.txt
@@ -90,7 +90,7 @@ add_component_dir (misc
     )
 
 add_component_dir (debug
-    debugging debuglog
+    debugging debuglog win32
     )
 
 IF(NOT WIN32 AND NOT APPLE)
diff --git a/components/debug/debugging.cpp b/components/debug/debugging.cpp
index e89a65956..9798950b9 100644
--- a/components/debug/debugging.cpp
+++ b/components/debug/debugging.cpp
@@ -52,6 +52,11 @@ namespace Debug
 
 int wrapApplication(int (*innerApplication)(int argc, char *argv[]), int argc, char *argv[], const std::string& appName)
 {
+#if defined _WIN32
+    // grab a console window if we don't have one
+    (void)Debug::attachParentConsole();
+#endif
+
     // Some objects used to redirect cout and cerr
     // Scope must be here, so this still works inside the catch block for logging exceptions
     std::streambuf* cout_rdbuf = std::cout.rdbuf ();
diff --git a/components/debug/debugging.hpp b/components/debug/debugging.hpp
index 361f321cb..440e8fa47 100644
--- a/components/debug/debugging.hpp
+++ b/components/debug/debugging.hpp
@@ -9,6 +9,9 @@
 #include <SDL_messagebox.h>
 
 #include "debuglog.hpp"
+#if defined _WIN32
+#   include "win32.hpp"
+#endif
 
 namespace Debug
 {
diff --git a/components/debug/win32.cpp b/components/debug/win32.cpp
new file mode 100644
index 000000000..9b038343c
--- /dev/null
+++ b/components/debug/win32.cpp
@@ -0,0 +1,56 @@
+#include "win32.hpp"
+
+#undef  _CRT_SECURE_NO_WARNINGS
+#define _CRT_SECURE_NO_WARNINGS
+
+#include <iostream>
+#include <cstdio>
+
+#include <windows.h>
+
+namespace Debug {
+
+bool attachParentConsole()
+{
+    // we already have a console window
+    if (GetConsoleWindow() != nullptr)
+        return true;
+
+    // our parent window has a console we can use
+    if (AttachConsole(ATTACH_PARENT_PROCESS))
+    {
+        // start with consistent state
+        fflush(stdin);
+        fflush(stderr);
+        std::cout.flush();
+        std::cerr.flush();
+
+        // fix fprintf(3) and fwprintf(3)
+        // this looks strange, but nothing is ever simple on Windows.
+        _wfreopen(L"CON", L"w", stdout);
+        _wfreopen(L"CON", L"w", stderr);
+        _wfreopen(L"CON", L"r", stdin);
+        freopen("CON", "w", stdout);
+        freopen("CON", "w", stderr);
+        freopen("CON", "w", stderr);
+
+        // it can be verified that input/output works as expected.
+#if 0
+        fprintf(stdout, "ascii stdout\n");
+        fwprintf(stdout, L"wide stdout\n");
+        fprintf(stderr, "ascii stderr\n");
+        fwprintf(stderr, L"wide stderr\n");
+
+        std::cout << "ascii cout\n";
+        std::cout << L"wide cout\n";
+        std::cerr << "ascii cerr\n";
+        std::cerr << L"wide cerr\n";
+#endif
+
+        return true;
+    }
+
+    return false;
+}
+
+} // ns Debug
diff --git a/components/debug/win32.hpp b/components/debug/win32.hpp
new file mode 100644
index 000000000..5a103cce5
--- /dev/null
+++ b/components/debug/win32.hpp
@@ -0,0 +1,5 @@
+#pragma once
+
+namespace Debug {
+    bool attachParentConsole();
+}