From c917cd4dbb31508628a8079e2720787b52b1f14b Mon Sep 17 00:00:00 2001
From: Peter Barker <pbarker@barker.dropbear.id.au>
Date: Mon, 2 Mar 2020 10:50:34 +1100
Subject: [PATCH] AP_HAL_Linux: make a static-const hal references references
 to external symbol

---
 libraries/AP_HAL_Linux/AnalogIn_Navio2.cpp  | 2 +-
 libraries/AP_HAL_Linux/GPIO.cpp             | 2 +-
 libraries/AP_HAL_Linux/GPIO_RPI.cpp         | 2 +-
 libraries/AP_HAL_Linux/GPIO_Sysfs.cpp       | 2 +-
 libraries/AP_HAL_Linux/HAL_Linux_Class.cpp  | 6 +++---
 libraries/AP_HAL_Linux/I2CDevice.cpp        | 4 ++--
 libraries/AP_HAL_Linux/Led_Sysfs.cpp        | 2 +-
 libraries/AP_HAL_Linux/PWM_Sysfs.cpp        | 2 +-
 libraries/AP_HAL_Linux/Perf.cpp             | 2 +-
 libraries/AP_HAL_Linux/RCOutput_AeroIO.cpp  | 2 +-
 libraries/AP_HAL_Linux/RCOutput_Bebop.cpp   | 2 +-
 libraries/AP_HAL_Linux/RCOutput_PCA9685.cpp | 2 +-
 libraries/AP_HAL_Linux/SPIDevice.cpp        | 4 ++--
 libraries/AP_Notify/RCOutputRGBLed.cpp      | 2 +-
 14 files changed, 18 insertions(+), 18 deletions(-)

diff --git a/libraries/AP_HAL_Linux/AnalogIn_Navio2.cpp b/libraries/AP_HAL_Linux/AnalogIn_Navio2.cpp
index c568332ee9..93e586d938 100644
--- a/libraries/AP_HAL_Linux/AnalogIn_Navio2.cpp
+++ b/libraries/AP_HAL_Linux/AnalogIn_Navio2.cpp
@@ -7,7 +7,7 @@
 
 #include "AnalogIn_Navio2.h"
 
-static const AP_HAL::HAL &hal = AP_HAL::get_HAL();
+extern const AP_HAL::HAL& hal;
 
 #define ADC_BASE_PATH "/sys/kernel/rcio/adc"
 
diff --git a/libraries/AP_HAL_Linux/GPIO.cpp b/libraries/AP_HAL_Linux/GPIO.cpp
index 4a29a4c485..69ba89282c 100644
--- a/libraries/AP_HAL_Linux/GPIO.cpp
+++ b/libraries/AP_HAL_Linux/GPIO.cpp
@@ -4,7 +4,7 @@
 
 using namespace Linux;
 
-static const AP_HAL::HAL& hal = AP_HAL::get_HAL();
+extern const AP_HAL::HAL& hal;
 
 DigitalSource::DigitalSource(uint8_t v) :
     _v(v)
diff --git a/libraries/AP_HAL_Linux/GPIO_RPI.cpp b/libraries/AP_HAL_Linux/GPIO_RPI.cpp
index 13f143b31b..a140b54aa0 100644
--- a/libraries/AP_HAL_Linux/GPIO_RPI.cpp
+++ b/libraries/AP_HAL_Linux/GPIO_RPI.cpp
@@ -36,7 +36,7 @@
 
 using namespace Linux;
 
-static const AP_HAL::HAL &hal = AP_HAL::get_HAL();
+extern const AP_HAL::HAL& hal;
 
 GPIO_RPI::GPIO_RPI()
 {
diff --git a/libraries/AP_HAL_Linux/GPIO_Sysfs.cpp b/libraries/AP_HAL_Linux/GPIO_Sysfs.cpp
index bca92728a9..eab54f49de 100644
--- a/libraries/AP_HAL_Linux/GPIO_Sysfs.cpp
+++ b/libraries/AP_HAL_Linux/GPIO_Sysfs.cpp
@@ -21,7 +21,7 @@
 
 using namespace Linux;
 
-static const AP_HAL::HAL& hal = AP_HAL::get_HAL();
+extern const AP_HAL::HAL& hal;
 
 #define UINT32_MAX_STR "4294967295"
 
diff --git a/libraries/AP_HAL_Linux/HAL_Linux_Class.cpp b/libraries/AP_HAL_Linux/HAL_Linux_Class.cpp
index 854f1583bf..54dba27a67 100644
--- a/libraries/AP_HAL_Linux/HAL_Linux_Class.cpp
+++ b/libraries/AP_HAL_Linux/HAL_Linux_Class.cpp
@@ -409,14 +409,14 @@ void HAL_Linux::setup_signal_handlers() const
     sigaction(SIGINT, &sa, NULL);
 }
 
-static HAL_Linux halInstance;
+HAL_Linux hal_linux;
 
 void HAL_Linux::exit_signal_handler(int signum)
 {
-    halInstance._should_exit = true;
+    hal_linux._should_exit = true;
 }
 
 const AP_HAL::HAL &AP_HAL::get_HAL()
 {
-    return halInstance;
+    return hal_linux;
 }
diff --git a/libraries/AP_HAL_Linux/I2CDevice.cpp b/libraries/AP_HAL_Linux/I2CDevice.cpp
index f995c3e1a6..ce59a8e8bd 100644
--- a/libraries/AP_HAL_Linux/I2CDevice.cpp
+++ b/libraries/AP_HAL_Linux/I2CDevice.cpp
@@ -56,9 +56,9 @@
 #define I2C_RDRW_IOCTL_MAX_MSGS 42
 #endif
 
-namespace Linux {
+extern const AP_HAL::HAL& hal;
 
-static const AP_HAL::HAL &hal = AP_HAL::get_HAL();
+namespace Linux {
 
 /*
  * TODO: move to Util or other upper class to be used by others
diff --git a/libraries/AP_HAL_Linux/Led_Sysfs.cpp b/libraries/AP_HAL_Linux/Led_Sysfs.cpp
index 5758cf6043..898b157048 100644
--- a/libraries/AP_HAL_Linux/Led_Sysfs.cpp
+++ b/libraries/AP_HAL_Linux/Led_Sysfs.cpp
@@ -26,7 +26,7 @@
 
 #include <AP_HAL/AP_HAL.h>
 
-static const AP_HAL::HAL &hal = AP_HAL::get_HAL();
+extern const AP_HAL::HAL& hal;
 
 namespace Linux {
 
diff --git a/libraries/AP_HAL_Linux/PWM_Sysfs.cpp b/libraries/AP_HAL_Linux/PWM_Sysfs.cpp
index fad21d72fe..680f82ec51 100644
--- a/libraries/AP_HAL_Linux/PWM_Sysfs.cpp
+++ b/libraries/AP_HAL_Linux/PWM_Sysfs.cpp
@@ -26,7 +26,7 @@
 #include <AP_HAL/AP_HAL.h>
 #include <AP_Math/AP_Math.h>
 
-static const AP_HAL::HAL &hal = AP_HAL::get_HAL();
+extern const AP_HAL::HAL& hal;
 
 namespace Linux {
 
diff --git a/libraries/AP_HAL_Linux/Perf.cpp b/libraries/AP_HAL_Linux/Perf.cpp
index 274b02108c..12c39d5aa9 100644
--- a/libraries/AP_HAL_Linux/Perf.cpp
+++ b/libraries/AP_HAL_Linux/Perf.cpp
@@ -33,7 +33,7 @@
 
 using namespace Linux;
 
-static const AP_HAL::HAL &hal = AP_HAL::get_HAL();
+extern const AP_HAL::HAL& hal;
 
 Perf *Perf::_singleton;
 
diff --git a/libraries/AP_HAL_Linux/RCOutput_AeroIO.cpp b/libraries/AP_HAL_Linux/RCOutput_AeroIO.cpp
index 4616dd23d8..1f61cf7325 100644
--- a/libraries/AP_HAL_Linux/RCOutput_AeroIO.cpp
+++ b/libraries/AP_HAL_Linux/RCOutput_AeroIO.cpp
@@ -91,7 +91,7 @@ using namespace Linux;
  *     uint16_t duty = 1823;
  */
 
-static const AP_HAL::HAL &hal = AP_HAL::get_HAL();
+extern const AP_HAL::HAL& hal;
 
 RCOutput_AeroIO::RCOutput_AeroIO()
     : _freq_buffer(new uint16_t[PWM_CHAN_COUNT])
diff --git a/libraries/AP_HAL_Linux/RCOutput_Bebop.cpp b/libraries/AP_HAL_Linux/RCOutput_Bebop.cpp
index 984245d792..88a674fde9 100644
--- a/libraries/AP_HAL_Linux/RCOutput_Bebop.cpp
+++ b/libraries/AP_HAL_Linux/RCOutput_Bebop.cpp
@@ -81,7 +81,7 @@ enum BLDC_STATUS {
 
 using namespace Linux;
 
-static const AP_HAL::HAL& hal = AP_HAL::get_HAL();
+extern const AP_HAL::HAL& hal;
 
 RCOutput_Bebop::RCOutput_Bebop(AP_HAL::OwnPtr<AP_HAL::I2CDevice> dev)
     : _dev(std::move(dev))
diff --git a/libraries/AP_HAL_Linux/RCOutput_PCA9685.cpp b/libraries/AP_HAL_Linux/RCOutput_PCA9685.cpp
index 8364932efb..4198df15cf 100644
--- a/libraries/AP_HAL_Linux/RCOutput_PCA9685.cpp
+++ b/libraries/AP_HAL_Linux/RCOutput_PCA9685.cpp
@@ -54,7 +54,7 @@ using namespace Linux;
 
 #define PWM_CHAN_COUNT 16
 
-static const AP_HAL::HAL& hal = AP_HAL::get_HAL();
+extern const AP_HAL::HAL& hal;
 
 RCOutput_PCA9685::RCOutput_PCA9685(AP_HAL::OwnPtr<AP_HAL::I2CDevice> dev,
                                    bool external_clock,
diff --git a/libraries/AP_HAL_Linux/SPIDevice.cpp b/libraries/AP_HAL_Linux/SPIDevice.cpp
index cd06293e01..ca4be42d21 100644
--- a/libraries/AP_HAL_Linux/SPIDevice.cpp
+++ b/libraries/AP_HAL_Linux/SPIDevice.cpp
@@ -39,9 +39,9 @@
 
 #define DEBUG 0
 
-namespace Linux {
+extern const AP_HAL::HAL& hal;
 
-static const AP_HAL::HAL &hal = AP_HAL::get_HAL();
+namespace Linux {
 
 #define MHZ (1000U*1000U)
 #define KHZ (1000U)
diff --git a/libraries/AP_Notify/RCOutputRGBLed.cpp b/libraries/AP_Notify/RCOutputRGBLed.cpp
index a52d03edce..bbd864f435 100644
--- a/libraries/AP_Notify/RCOutputRGBLed.cpp
+++ b/libraries/AP_Notify/RCOutputRGBLed.cpp
@@ -20,7 +20,7 @@
 #include <AP_Math/AP_Math.h>
 #include <SRV_Channel/SRV_Channel.h>
 
-static const AP_HAL::HAL& hal = AP_HAL::get_HAL();
+extern const AP_HAL::HAL& hal;
 
 #define LED_OFF 0
 #define LED_FULL_BRIGHT 255