Suppress spurious deprecated declaration warnings

Some generic compatibility functions emit deprecated declaration warnings
even when platforms do not use the deprecated functions directly. This
can be confusing. Suppress these warnings by using:
`#pragma GCC diagnostic ignored "-Wdeprecated-declarations"`

Also emit a runtime warning if the weak plat/common implemntation of
plat_get_syscnt_freq2() is used, as this implies the platform has not
migrated from plat_get_syscnt_freq(). The deprecated  declaration warnings
only help detect when platforms are calling deprecated functions, not when
they are defining deprecated functions.

Fixes ARM-software/tf-issues#550

Change-Id: Id14a92279c2634c1e76db8ef210da8affdbb2a5d
Signed-off-by: Dan Handley <dan.handley@arm.com>

bl31/bl31_context_mgmt.c

@@ -79,7 +79,13 @@ void *cm_get_context_by_mpidr(uint64_t mpidr, uint32_t security_state)
 {
 	assert(sec_state_is_valid(security_state));
 
+	/*
+	 * Suppress deprecated declaration warning in compatibility function
+	 */
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
 	return cm_get_context_by_index(platform_get_core_pos(mpidr), security_state);
+#pragma GCC diagnostic pop
 }
 
 /*******************************************************************************
@@ -90,8 +96,14 @@ void cm_set_context_by_mpidr(uint64_t mpidr, void *context, uint32_t security_st
 {
 	assert(sec_state_is_valid(security_state));
 
+	/*
+	 * Suppress deprecated declaration warning in compatibility function
+	 */
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
 	cm_set_context_by_index(platform_get_core_pos(mpidr),
 						 context, security_state);
+#pragma GCC diagnostic pop
 }
 
 /*******************************************************************************
@@ -104,7 +116,15 @@ void cm_init_context(uint64_t mpidr, const entry_point_info_t *ep)
 	if ((mpidr & MPIDR_AFFINITY_MASK) ==
 			(read_mpidr_el1() & MPIDR_AFFINITY_MASK))
 		cm_init_my_context(ep);
-	else
+	else {
+		/*
+		 * Suppress deprecated declaration warning in compatibility
+		 * function
+		 */
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
 		cm_init_context_by_index(platform_get_core_pos(mpidr), ep);
+#pragma GCC diagnostic pop
+	}
 }
-#endif
+#endif /* ERROR_DEPRECATED */

plat/common/aarch64/plat_common.c

@@ -65,7 +65,15 @@ unsigned int platform_core_pos_helper(unsigned long mpidr)
 #if !ERROR_DEPRECATED
 unsigned int plat_get_syscnt_freq2(void)
 {
+	WARN("plat_get_syscnt_freq() is deprecated\n");
+	WARN("Please define plat_get_syscnt_freq2()\n");
+	/*
+	 * Suppress deprecated declaration warning in compatibility function
+	 */
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
 	unsigned long long freq = plat_get_syscnt_freq();
+#pragma GCC diagnostic pop
 
 	assert(freq >> 32 == 0);