Do not warn about unused macros while processing #pragma GCC optimize

libcpp

	PR c++/91318
	* include/cpplib.h: Added cpp_define_unused(), cpp_define_formatted_unused()
	* directives.c: Likewise.

gcc/c-family

	PR c++/91318
	* c-cppbuiltin.c: c_cpp_builtins_optimize_pragma(): use cpp_define_unused()

2 files changed, 27 insertions, 0 deletions

diff --git a/libcpp/directives.c b/libcpp/directives.c
index 4295a67..c4ecb96 100644
--- a/libcpp/directives.c
+++ b/libcpp/directives.c
@@ -2412,6 +2412,15 @@ cpp_define (cpp_reader *pfile, const char *str)
   run_directive (pfile, T_DEFINE, buf, count);
 }
 
+/* Like cpp_define, but does not warn about unused macro.  */
+void
+cpp_define_unused (cpp_reader *pfile, const char *str)
+{
+    unsigned char warn_unused_macros = CPP_OPTION (pfile, warn_unused_macros);
+    CPP_OPTION (pfile, warn_unused_macros) = 0;
+    cpp_define (pfile, str);
+    CPP_OPTION (pfile, warn_unused_macros) = warn_unused_macros;
+}
 
 /* Use to build macros to be run through cpp_define() as
    described above.
@@ -2431,6 +2440,20 @@ cpp_define_formatted (cpp_reader *pfile, const char *fmt, ...)
   free (ptr);
 }
 
+/* Like cpp_define_formatted, but does not warn about unused macro.  */
+void
+cpp_define_formatted_unused (cpp_reader *pfile, const char *fmt, ...)
+{
+  char *ptr;
+
+  va_list ap;
+  va_start (ap, fmt);
+  ptr = xvasprintf (fmt, ap);
+  va_end (ap);
+
+  cpp_define_unused (pfile, ptr);
+  free (ptr);
+}
 
 /* Slight variant of the above for use by initialize_builtins.  */
 void
diff --git a/libcpp/include/cpplib.h b/libcpp/include/cpplib.h
index 8900e77..ce00952 100644
--- a/libcpp/include/cpplib.h
+++ b/libcpp/include/cpplib.h
@@ -1076,8 +1076,12 @@ extern cppchar_t cpp_host_to_exec_charset (cpp_reader *, cppchar_t);
 /* Used to register macros and assertions, perhaps from the command line.
    The text is the same as the command line argument.  */
 extern void cpp_define (cpp_reader *, const char *);
+extern void cpp_define_unused (cpp_reader *, const char *);
 extern void cpp_define_formatted (cpp_reader *pfile, 
 				  const char *fmt, ...) ATTRIBUTE_PRINTF_2;
+extern void cpp_define_formatted_unused (cpp_reader *pfile,
+					 const char *fmt,
+					 ...) ATTRIBUTE_PRINTF_2;
 extern void cpp_assert (cpp_reader *, const char *);
 extern void cpp_undef (cpp_reader *, const char *);
 extern void cpp_unassert (cpp_reader *, const char *);