Merge pull request #5731 from tautschnig/attribute-alias

GCC attribute alias should not trigger warning

Author: tautschnig

regression/ansi-c/gcc_attributes12/test.desc

@@ -1,8 +1,9 @@
 CORE gcc-only
 main.c
-
+-Wall
 ^EXIT=0$
 ^SIGNAL=0$
 --
+'extern' symbol 'my_ids_table' should not have an initializer
 ^warning: ignoring
 ^CONVERSION ERROR$

src/ansi-c/c_typecheck_base.cpp

@@ -73,13 +73,14 @@ void c_typecheck_baset::typecheck_symbol(symbolt &symbol)
     new_name=root_name;
     symbol.is_static_lifetime=true;
 
-    if(symbol.value.is_not_nil())
+    if(symbol.value.is_not_nil() && !symbol.is_macro)
     {
       // According to the C standard this should be an error, but at least some
       // versions of Visual Studio insist to use this in their C library, and
       // GCC just warns as well.
       warning().source_location = symbol.value.find_source_location();
-      warning() << "`extern' symbol should not have an initializer" << eom;
+      warning() << "'extern' symbol '" << new_name
+                << "' should not have an initializer" << eom;
     }
   }
   else if(!is_function && symbol.value.id()==ID_code)