From 8f3474ecfdb00d41281f265510b315b2b9161e1e Mon Sep 17 00:00:00 2001
From: Peter Veenstra <qbix79@users.sourceforge.net>
Date: Sun, 10 Nov 2019 14:50:11 +0000
Subject: [PATCH] Make it possible to compile without CoreMIDI and CoreAudio on
 Mac OS X using a non-Apple compiler. Give some feedback to user in this case.
 (modified version of patch by krcroft with input from jmarsh, Dominus and
 Qbix)

Imported-from: https://svn.code.sf.net/p/dosbox/code-0/dosbox/trunk@4281
---
 configure.ac     | 28 +++++++++++++++++++++++++++-
 include/midi.h   |  9 ++++++++-
 src/gui/midi.cpp |  8 +++++++-
 3 files changed, 42 insertions(+), 3 deletions(-)

diff --git a/configure.ac b/configure.ac
index af394c65..d65acfbc 100644
--- a/configure.ac
+++ b/configure.ac
@@ -189,6 +189,33 @@ CXXFLAGS="$CXXFLAGS -mno-ms-bitfields"
 ],[AC_MSG_RESULT([no])])
 CFLAGS="$BACKUP_CFLAGS"
 
+dnl When on macOS, enable support for Apple's Core MIDI and/or Core Audio if our compiler can #include their headers
+case "$host" in
+  *-*-darwin*)
+   AC_MSG_CHECKING(if compiler supports Apple's Core MIDI headers)
+   AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
+   #include <CoreMIDI/MIDIServices.h>
+   int blah() { return 0; }
+   ]])], [AC_MSG_RESULT(yes);LIBS="$LIBS -framework CoreMIDI";AC_DEFINE([C_SUPPORTS_COREMIDI], [],
+   [Compiler supports Core MIDI headers])],
+   AC_MSG_RESULT(no);AC_MSG_WARN([Compiler can't compile Apple headers. CoreMIDI functionality disabled. Please use the Apple compiler!]))
+
+   AC_MSG_CHECKING(if compiler supports Apple's Core Audio headers)
+   AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
+   #include <AudioToolbox/AUGraph.h>
+   #include <CoreServices/CoreServices.h>
+   int blah() { return 0; }
+   ]])], [AC_MSG_RESULT(yes);LIBS="$LIBS -framework AudioUnit -framework AudioToolbox";AC_DEFINE([C_SUPPORTS_COREAUDIO], [],
+   [Compiler supports Core Audio headers])], 
+   AC_MSG_RESULT(no);AC_MSG_WARN([Compiler can't compile Apple headers. CoreAudio functionality disabled. Please use the Apple compiler!]))
+   ;;
+
+  *)
+   AC_MSG_CHECKING(if compiler supports Apple's MIDI headers)
+   AC_MSG_RESULT([no, not on Apple])
+   ;;
+esac
+
 dnl enable disable alsa and pass it's cflags to CXXFLAGS
 AC_ARG_ENABLE(alsa-midi,
 AC_HELP_STRING([--enable-alsa-midi],[compile with alsa midi support (default yes)]),
@@ -564,7 +591,6 @@ case "$host" in
        dnl to do more to distinguish them.
        dnl For now I am lazy and do not add proper detection code.
        AC_DEFINE(MACOSX, 1, [Compiling on Mac OS X])
-       LIBS="$LIBS -framework CoreMIDI -framework AudioUnit -framework AudioToolbox"
        AC_DEFINE(C_DIRECTSERIAL, 1, [ Define to 1 if you want serial passthrough support (Win32, Posix and OS/2).])
        ;;
     *-*-linux*)
diff --git a/include/midi.h b/include/midi.h
index ea9afdad..773b6e6c 100644
--- a/include/midi.h
+++ b/include/midi.h
@@ -20,6 +20,10 @@
 #ifndef DOSBOX_MIDI_H
 #define DOSBOX_MIDI_H
 
+#ifndef DOSBOX_DOSBOX_H
+#include "dosbox.h"
+#endif
+
 #ifndef DOSBOX_PROGRAMS_H
 #include "programs.h"
 #endif
@@ -27,7 +31,10 @@
 class MidiHandler {
 public:
 	MidiHandler();
-	virtual bool Open(const char * /*conf*/) { return true; };
+	virtual bool Open(const char * /*conf*/) { 
+		LOG_MSG("No working midi device found/selected! Please check your settings and/or compilation environment.");
+		return true; 
+	};
 	virtual void Close(void) {};
 	virtual void PlayMsg(Bit8u * /*msg*/) {};
 	virtual void PlaySysex(Bit8u * /*sysex*/,Bitu /*len*/) {};
diff --git a/src/gui/midi.cpp b/src/gui/midi.cpp
index b5361051..28b65f46 100644
--- a/src/gui/midi.cpp
+++ b/src/gui/midi.cpp
@@ -68,12 +68,18 @@ MidiHandler::MidiHandler(){
 
 MidiHandler Midi_none;
 
-/* Include different midi drivers, lowest ones get checked first for default */
+/* Include different midi drivers, lowest ones get checked first for default.
+   Each header provides an independent midi interface. */
 
 #if defined(MACOSX)
 
+#if defined(C_SUPPORTS_COREMIDI)
 #include "midi_coremidi.h"
+#endif
+
+#if defined(C_SUPPORTS_COREAUDIO)
 #include "midi_coreaudio.h"
+#endif
 
 #elif defined (WIN32)