From 07e672c448e2a4ea56ae793f1c6dae26d908b16e Mon Sep 17 00:00:00 2001
From: Gaurav-Aggarwal-AWS <33462878+aggarg@users.noreply.github.com>
Date: Tue, 14 Apr 2020 09:03:11 -0700
Subject: [PATCH] Add definition of portDONT_DISCARD to ARMv7-M ports (#50)

Enabling Link Time Optimization (LTO) causes some of the functions used
in assembly to be incorrectly stripped off, resulting in linker error.
To avoid this, these functions are marked with portDONT_DISCARD macro,
definition of which is port specific. This commit adds the definition
of portDONT_DISCARD for ARMv7-M ports.

Signed-off-by: Gaurav Aggarwal
---
 portable/GCC/ARM_CM0/portmacro.h      | 1 +
 portable/GCC/ARM_CM3/portmacro.h      | 1 +
 portable/GCC/ARM_CM3_MPU/portmacro.h  | 1 +
 portable/GCC/ARM_CM4F/portmacro.h     | 1 +
 portable/GCC/ARM_CM4_MPU/portmacro.h  | 1 +
 portable/GCC/ARM_CM7/r0p1/portmacro.h | 1 +
 6 files changed, 6 insertions(+)

diff --git a/portable/GCC/ARM_CM0/portmacro.h b/portable/GCC/ARM_CM0/portmacro.h
index 3b402b428..2e59a83dc 100644
--- a/portable/GCC/ARM_CM0/portmacro.h
+++ b/portable/GCC/ARM_CM0/portmacro.h
@@ -73,6 +73,7 @@ typedef unsigned long UBaseType_t;
 #define portSTACK_GROWTH			( -1 )
 #define portTICK_PERIOD_MS			( ( TickType_t ) 1000 / configTICK_RATE_HZ )
 #define portBYTE_ALIGNMENT			8
+#define portDONT_DISCARD			__attribute__(( used ))
 /*-----------------------------------------------------------*/
 
 
diff --git a/portable/GCC/ARM_CM3/portmacro.h b/portable/GCC/ARM_CM3/portmacro.h
index 29bccbb2e..673d93757 100644
--- a/portable/GCC/ARM_CM3/portmacro.h
+++ b/portable/GCC/ARM_CM3/portmacro.h
@@ -73,6 +73,7 @@ typedef unsigned long UBaseType_t;
 #define portSTACK_GROWTH			( -1 )
 #define portTICK_PERIOD_MS			( ( TickType_t ) 1000 / configTICK_RATE_HZ )
 #define portBYTE_ALIGNMENT			8
+#define portDONT_DISCARD			__attribute__(( used ))
 /*-----------------------------------------------------------*/
 
 /* Scheduler utilities. */
diff --git a/portable/GCC/ARM_CM3_MPU/portmacro.h b/portable/GCC/ARM_CM3_MPU/portmacro.h
index eef435801..61da7413a 100644
--- a/portable/GCC/ARM_CM3_MPU/portmacro.h
+++ b/portable/GCC/ARM_CM3_MPU/portmacro.h
@@ -109,6 +109,7 @@ typedef struct MPU_SETTINGS
 #define portSTACK_GROWTH			( -1 )
 #define portTICK_PERIOD_MS			( ( TickType_t ) 1000 / configTICK_RATE_HZ )
 #define portBYTE_ALIGNMENT			8
+#define portDONT_DISCARD			__attribute__(( used ))
 /*-----------------------------------------------------------*/
 
 /* SVC numbers for various services. */
diff --git a/portable/GCC/ARM_CM4F/portmacro.h b/portable/GCC/ARM_CM4F/portmacro.h
index e1e7fadf3..b94366dfd 100644
--- a/portable/GCC/ARM_CM4F/portmacro.h
+++ b/portable/GCC/ARM_CM4F/portmacro.h
@@ -73,6 +73,7 @@ typedef unsigned long UBaseType_t;
 #define portSTACK_GROWTH			( -1 )
 #define portTICK_PERIOD_MS			( ( TickType_t ) 1000 / configTICK_RATE_HZ )
 #define portBYTE_ALIGNMENT			8
+#define portDONT_DISCARD			__attribute__(( used ))
 /*-----------------------------------------------------------*/
 
 /* Scheduler utilities. */
diff --git a/portable/GCC/ARM_CM4_MPU/portmacro.h b/portable/GCC/ARM_CM4_MPU/portmacro.h
index eef435801..61da7413a 100644
--- a/portable/GCC/ARM_CM4_MPU/portmacro.h
+++ b/portable/GCC/ARM_CM4_MPU/portmacro.h
@@ -109,6 +109,7 @@ typedef struct MPU_SETTINGS
 #define portSTACK_GROWTH			( -1 )
 #define portTICK_PERIOD_MS			( ( TickType_t ) 1000 / configTICK_RATE_HZ )
 #define portBYTE_ALIGNMENT			8
+#define portDONT_DISCARD			__attribute__(( used ))
 /*-----------------------------------------------------------*/
 
 /* SVC numbers for various services. */
diff --git a/portable/GCC/ARM_CM7/r0p1/portmacro.h b/portable/GCC/ARM_CM7/r0p1/portmacro.h
index c01d305dc..124e8073a 100644
--- a/portable/GCC/ARM_CM7/r0p1/portmacro.h
+++ b/portable/GCC/ARM_CM7/r0p1/portmacro.h
@@ -73,6 +73,7 @@ typedef unsigned long UBaseType_t;
 #define portSTACK_GROWTH			( -1 )
 #define portTICK_PERIOD_MS			( ( TickType_t ) 1000 / configTICK_RATE_HZ )
 #define portBYTE_ALIGNMENT			8
+#define portDONT_DISCARD			__attribute__(( used ))
 /*-----------------------------------------------------------*/
 
 /* Scheduler utilities. */