Fix oboe driver build issue in latest glib

src/drivers/fluid_adriver.h

@@ -23,6 +23,10 @@
 
 #include "fluidsynth_priv.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /*
  * fluid_audio_driver_t
  */
@@ -167,6 +171,8 @@ fluid_audio_driver_t *new_fluid_file_audio_driver(fluid_settings_t *settings,
 void delete_fluid_file_audio_driver(fluid_audio_driver_t *p);
 #endif
 
-
+#ifdef __cplusplus
+}
+#endif
 
 #endif  /* _FLUID_AUDRIVER_H */

src/drivers/fluid_oboe.cpp

@@ -25,13 +25,9 @@
  * This file may make use of C++14, because it's required by oboe anyway.
  */
 
-extern "C" {
-
 #include "fluid_adriver.h"
 #include "fluid_settings.h"
 
-} // extern "C"
-
 #if OBOE_SUPPORT
 
 #include <oboe/Oboe.h>

src/utils/fluid_settings.h

@@ -22,6 +22,10 @@
 #ifndef _FLUID_SETTINGS_H
 #define _FLUID_SETTINGS_H
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 int fluid_settings_add_option(fluid_settings_t *settings, const char *name, const char *s);
 int fluid_settings_remove_option(fluid_settings_t *settings, const char *name, const char *s);
 
@@ -54,4 +58,8 @@ int fluid_settings_split_csv(const char *str, int *buf, int buf_len);
 
 void* fluid_settings_get_user_data(fluid_settings_t * settings, const char *name);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* _FLUID_SETTINGS_H */

src/utils/fluidsynth_priv.h

@@ -48,6 +48,9 @@
 
 #include "fluidsynth.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
 
 /***************************************************************
  *
@@ -318,5 +321,8 @@ else \
 #define fluid_return_val_if_fail(cond, val) \
  fluid_return_if_fail(cond) (val)
 
+#ifdef __cplusplus
+}
+#endif
 
 #endif /* _FLUIDSYNTH_PRIV_H */