ARM: Introduce ARM_DEFAULT_SHORT_ENUMS

Allow targets to define the default for the short enums option.

gcc/

	* config/arm/arm.h (ARM_DEFAULT_SHORT_ENUMS): Provide default
	definition.
	* config/arm/arm.c (arm_default_short_enums): Use
	ARM_DEFAULT_SHORT_ENUMS.
	* config/arm/rtems.h (ARM_DEFAULT_SHORT_ENUMS): Define.

From-SVN: r246753

gcc/ChangeLog

+2017-04-07  Sebastian Huber  <sebastian.huber@embedded-brains.de>
+
+	* config/arm/arm.h (ARM_DEFAULT_SHORT_ENUMS): Provide default
+	definition.
+	* config/arm/arm.c (arm_default_short_enums): Use
+	ARM_DEFAULT_SHORT_ENUMS.
+	* config/arm/rtems.h (ARM_DEFAULT_SHORT_ENUMS): Define.
+
 2017-04-06  Jakub Jelinek  <jakub@redhat.com>
 
 	PR debug/80234

gcc/config/arm/arm.c

@@ -26549,12 +26549,11 @@ arm_promote_function_mode (const_tree type ATTRIBUTE_UNUSED,
   return mode;
 }
 
-/* AAPCS based ABIs use short enums by default.  */
 
 static bool
 arm_default_short_enums (void)
 {
-  return TARGET_AAPCS_BASED && arm_abi != ARM_ABI_AAPCS_LINUX;
+  return ARM_DEFAULT_SHORT_ENUMS;
 }
 
 

gcc/config/arm/arm.h

@@ -343,6 +343,12 @@ extern int arm_fpu_attr;
 #define ARM_DEFAULT_ABI ARM_ABI_APCS
 #endif
 
+/* AAPCS based ABIs use short enums by default.  */
+#ifndef ARM_DEFAULT_SHORT_ENUMS
+#define ARM_DEFAULT_SHORT_ENUMS \
+  (TARGET_AAPCS_BASED && arm_abi != ARM_ABI_AAPCS_LINUX)
+#endif
+
 /* Map each of the micro-architecture variants to their corresponding
    major architecture revision.  */
 

gcc/config/arm/rtems.h

@@ -27,3 +27,5 @@
 	builtin_assert ("system=rtems");	\
 	TARGET_BPABI_CPP_BUILTINS();    	\
     } while (0)
+
+#define ARM_DEFAULT_SHORT_ENUMS false