re PR target/69180 ([ARM] #pragma GCC target should not warn about redefined macros)

PR target/69180
* config/arm/arm-c.c (arm_pragma_target_parse): Set NODE_CONDITIONAL
for __ARM_NEON_FP, __ARM_FP, _ARM_FEATURE_LDREX.

From-SVN: r232276

gcc/ChangeLog

+2016-01-12  Christian Bruel  <christian.bruel@st.com>
+
+	PR target/69180
+	* config/arm/arm-c.c (arm_pragma_target_parse): Set NODE_CONDITIONAL
+	for __ARM_NEON_FP, __ARM_FP, _ARM_FEATURE_LDREX.
+
 2016-01-12  Jakub Jelinek  <jakub@redhat.com>
 
 	PR target/69198

gcc/config/arm/arm-c.c

@@ -23,6 +23,7 @@
 #include "c-family/c-common.h"
 #include "tm_p.h"
 #include "c-family/c-pragma.h"
+#include "stringpool.h"
 
 /* Output C specific EABI object attributes.  These can not be done in
    arm.c because they require information from the C frontend.  */
@@ -245,8 +246,18 @@ arm_pragma_target_parse (tree args, tree pop_target)
 
       /* Update macros.  */
       gcc_assert (cur_opt->x_target_flags == target_flags);
-      /* This one can be redefined by the pragma without warning.  */
-      cpp_undef (parse_in, "__ARM_FP");
+
+      /* Don't warn for macros that have context sensitive values depending on
+	 other attributes.
+	 See warn_of_redefinition, Reset after cpp_create_definition.  */
+      tree acond_macro = get_identifier ("__ARM_NEON_FP");
+      C_CPP_HASHNODE (acond_macro)->flags |= NODE_CONDITIONAL ;
+
+      acond_macro = get_identifier ("__ARM_FP");
+      C_CPP_HASHNODE (acond_macro)->flags |= NODE_CONDITIONAL;
+
+      acond_macro = get_identifier ("__ARM_FEATURE_LDREX");
+      C_CPP_HASHNODE (acond_macro)->flags |= NODE_CONDITIONAL;
 
       arm_cpu_builtins (parse_in);
 

gcc/testsuite/ChangeLog

+2016-01-12  Christian Bruel  <christian.bruel@st.com>
+
+	PR target/69180
+	* gcc.target/arm/pr69180.c: New test.
+
 2016-01-12  Richard Biener  <rguenther@suse.de>
 
 	PR lto/69077