From 72121bc7d88bbd6577cd3ea88b301d91ac35d675 Mon Sep 17 00:00:00 2001
From: Povilas Kanapickas <povilas@radix.lt>
Date: Fri, 10 May 2019 21:16:10 +0300
Subject: [PATCH] sanei: Use C linkage for internal functions in C++ mode

---
 backend/stubs.c              | 8 ++++++++
 include/sane/sanei.h         | 7 +++++++
 include/sane/sanei_backend.h | 8 ++++++++
 include/sane/sanei_config.h  | 8 ++++++++
 include/sane/sanei_debug.h   | 8 ++++++++
 include/sane/sanei_magic.h   | 8 ++++++++
 include/sane/sanei_usb.h     | 8 ++++++++
 7 files changed, 55 insertions(+)

diff --git a/backend/stubs.c b/backend/stubs.c
index 3fb5ce3d6..a8afd3e4e 100644
--- a/backend/stubs.c
+++ b/backend/stubs.c
@@ -5,6 +5,10 @@
 /* Now define the wrappers (we could use aliases here, but go for
    robustness for now...: */
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 SANE_Status
 sane_init (SANE_Int *vc, SANE_Auth_Callback cb)
 {
@@ -83,3 +87,7 @@ sane_exit (void)
 {
   ENTRY(exit) ();
 }
+
+#ifdef __cplusplus
+} // extern "C"
+#endif
diff --git a/include/sane/sanei.h b/include/sane/sanei.h
index 4ff765d74..aa7003ad1 100644
--- a/include/sane/sanei.h
+++ b/include/sane/sanei.h
@@ -89,6 +89,10 @@
 
 #include <sane/sane.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /** @name Public macros and functions
  * @{
  */
@@ -167,5 +171,8 @@ extern SANE_Status sanei_check_value (const SANE_Option_Descriptor * opt,
 extern SANE_Status sanei_constrain_value (const SANE_Option_Descriptor * opt,
 					  void * value, SANE_Word * info);
 
+#ifdef __cplusplus
+} // extern "C"
+#endif
 
 #endif /* sanei_h */
diff --git a/include/sane/sanei_backend.h b/include/sane/sanei_backend.h
index 89e2edb64..32d8ce0c8 100644
--- a/include/sane/sanei_backend.h
+++ b/include/sane/sanei_backend.h
@@ -113,6 +113,10 @@
 /** @name Declaration of entry points:
  * @{
  */
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 extern SANE_Status ENTRY(init) (SANE_Int *, SANE_Auth_Callback);
 extern SANE_Status ENTRY(get_devices) (const SANE_Device ***, SANE_Bool);
 extern SANE_Status ENTRY(open) (SANE_String_Const, SANE_Handle *);
@@ -130,6 +134,10 @@ extern void ENTRY(cancel) (SANE_Handle);
 extern void ENTRY(close) (SANE_Handle);
 extern void ENTRY(exit) (void);
 
+#ifdef __cplusplus
+} // extern "C"
+#endif
+
 #ifndef STUBS
 /* Now redirect sane_* calls to backend's functions: */
 
diff --git a/include/sane/sanei_config.h b/include/sane/sanei_config.h
index f81bdd49f..3a6016736 100644
--- a/include/sane/sanei_config.h
+++ b/include/sane/sanei_config.h
@@ -52,6 +52,10 @@
 #include <stdio.h>
 #include <sane/sane.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /** Search configuration file \a name along directory list and return file
  * pointer if such a file exists.
  *
@@ -172,4 +176,8 @@ extern SANE_Status sanei_configure_attach (
  */
 extern const char *sanei_config_get_paths (void);
 
+#ifdef __cplusplus
+} // extern "C"
+#endif
+
 #endif	/* sanei_config_h */
diff --git a/include/sane/sanei_debug.h b/include/sane/sanei_debug.h
index 5198af400..465d3e25e 100644
--- a/include/sane/sanei_debug.h
+++ b/include/sane/sanei_debug.h
@@ -9,6 +9,10 @@
 
 #include <sane/sanei.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /** @name Public macros
  * These macros can be used in backends and other SANE-related
  * code.
@@ -150,4 +154,8 @@ extern void sanei_init_debug (const char * backend, int * debug_level_var);
 
 #endif /* NDEBUG */
 
+#ifdef __cplusplus
+} // extern "C"
+#endif
+
 #endif /* _SANEI_DEBUG_H */
diff --git a/include/sane/sanei_magic.h b/include/sane/sanei_magic.h
index ba6a43286..297becdfc 100644
--- a/include/sane/sanei_magic.h
+++ b/include/sane/sanei_magic.h
@@ -57,6 +57,10 @@
 #ifndef SANEI_MAGIC_H
 #define SANEI_MAGIC_H
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /** Initialize sanei_magic.
  *
  * Call this before any other sanei_magic function.
@@ -219,4 +223,8 @@ extern SANE_Status
 sanei_magic_turn(SANE_Parameters * params, SANE_Byte * buffer,
   int angle);
 
+#ifdef __cplusplus
+} // extern "C"
+#endif
+
 #endif /* SANEI_MAGIC_H */
diff --git a/include/sane/sanei_usb.h b/include/sane/sanei_usb.h
index c8fff97a4..ce389cad5 100644
--- a/include/sane/sanei_usb.h
+++ b/include/sane/sanei_usb.h
@@ -68,6 +68,10 @@
 
 #include <stdlib.h> /* for size_t */
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* USB spec defines */
 #ifndef USB_CLASS_PER_INTERFACE
 /* Also defined in libusb */
@@ -521,5 +525,9 @@ sanei_usb_set_altinterface (SANE_Int dn, SANE_Int alternate);
 extern SANE_Status
 sanei_usb_get_descriptor( SANE_Int dn, struct sanei_usb_dev_descriptor *desc );
 
+#ifdef __cplusplus
+} // extern "C"
+#endif
+
 /*------------------------------------------------------*/
 #endif /* sanei_usb_h */