File Fix_build_with_GCC10.patch of Package bumblebee.openSUSE_Backports_SLE-15-SP4

 Author: Andreas Beckmann <anbe@debian.org> Description: fix
 FTBFS with gcc-10  gcc-10 defaults to -fno-common  see
 https://gcc.gnu.org/gcc-10/porting_to.html Bug-Debian:
 https://bugs.debian.org/957058

---
 src/bbconfig.h         | 2 +-
 src/bbsecondary.c      | 3 +++
 src/bbsecondary.h      | 2 +-
 src/switch/switching.c | 2 ++
 src/switch/switching.h | 4 ++--
 5 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/src/bbconfig.h b/src/bbconfig.h
index 5596b64..78b0d49 100644
--- a/src/bbconfig.h
+++ b/src/bbconfig.h
@@ -102,7 +102,7 @@ enum bb_pm_method {
     PM_VGASWITCHEROO,
     PM_METHODS_COUNT /* not a method but a marker for the end */
 };
-const char *bb_pm_method_string[PM_METHODS_COUNT];
+extern const char *bb_pm_method_string[PM_METHODS_COUNT];
 
 /* String buffer size */
 #define BUFFER_SIZE 1024
diff --git a/src/bbsecondary.c b/src/bbsecondary.c
index 71a6b73..9cc449b 100644
--- a/src/bbsecondary.c
+++ b/src/bbsecondary.c
@@ -37,6 +37,9 @@
 #include "pci.h"
 #include "module.h"
 
+/* PCI Bus ID of the discrete video card */
+struct pci_bus_id *pci_bus_id_discrete;
+
 /**
  * Substitutes DRIVER in the passed path
  * @param x_conf_file A path to be processed
diff --git a/src/bbsecondary.h b/src/bbsecondary.h
index 291c20f..d69b726 100644
--- a/src/bbsecondary.h
+++ b/src/bbsecondary.h
@@ -29,7 +29,7 @@
 #define XORG_BINARY "Xorg"
 
 /* PCI Bus ID of the discrete video card */
-struct pci_bus_id *pci_bus_id_discrete;
+extern struct pci_bus_id *pci_bus_id_discrete;
 
 /// Start the X server by fork-exec, turn card on if needed.
 bool start_secondary(bool);
diff --git a/src/switch/switching.c b/src/switch/switching.c
index 7ed716e..4872122 100644
--- a/src/switch/switching.c
+++ b/src/switch/switching.c
@@ -31,6 +31,8 @@ struct switching_method switching_methods[SWITCHERS_COUNT] = {
           switcheroo_on, switcheroo_off}
 };
 
+struct switching_method *switcher = NULL;
+
 /**
  * Enumerates through available switching methods and try a method
  * 
diff --git a/src/switch/switching.h b/src/switch/switching.h
index e0a54bc..4e7b03a 100644
--- a/src/switch/switching.h
+++ b/src/switch/switching.h
@@ -60,10 +60,10 @@ void switcheroo_off(void);
 
 /* number of switchers as defined in switching.c */
 #define SWITCHERS_COUNT 2
-struct switching_method switching_methods[SWITCHERS_COUNT];
+extern struct switching_method switching_methods[SWITCHERS_COUNT];
 
 /* A switching method that can be used or NULL if none */
-struct switching_method *switcher;
+extern struct switching_method *switcher;
 
 struct switching_method *switcher_detect(const char *name, struct switch_info);
 enum switch_state switch_status(void);
-- 
2.28.0