+/* This macro allows casting away const-ness to pass -Wcast-qual
+ warnings. DO NOT USE THIS UNLESS YOU REALLY HAVE TO! It should
+ only be used in certain specific cases. One valid case is where
+ the C standard definitions or prototypes force you to. E.g. if you
+ need to free a const object, or if you pass a const string to
+ execv, et al. Another valid use would be in an allocation function
+ that creates const objects that need to be initialized. In some
+ cases we have non-const functions that return the argument
+ (e.g. next_nonnote_insn). Rather than create const shadow
+ functions, we can cast away const-ness in calling these interfaces
+ if we're careful to verify that the called function does indeed not
+ modify its argument and the return value is only used in a const
+ context. (This can be somewhat dangerous as these assumptions can
+ change after the fact). Beyond these uses, most other cases of
+ using this macro should be viewed with extreme caution. */
+
+#if defined(__GNUC__) && GCC_VERSION > 4000
+/* GCC 4.0.x has a bug where it may ICE on this expression,
+ so does GCC 3.4.x (PR17436). */
+#define CONST_CAST2(TOTYPE,FROMTYPE,X) ((__extension__(union {FROMTYPE _q; TOTYPE _nq;})(X))._nq)
+#else
+#define CONST_CAST2(TOTYPE,FROMTYPE,X) ((TOTYPE)(FROMTYPE)(X))
+#endif
+#define CONST_CAST(TYPE,X) CONST_CAST2(TYPE, const TYPE, (X))
+#define CONST_CAST_TREE(X) CONST_CAST(union tree_node *, (X))
+#define CONST_CAST_RTX(X) CONST_CAST(struct rtx_def *, (X))
+#define CONST_CAST_BB(X) CONST_CAST(struct basic_block_def *, (X))
+#define CONST_CAST_GIMPLE(X) CONST_CAST(union gimple_statement_d *, (X))
+
+/* Activate certain diagnostics as warnings (not errors via the
+ -Werror flag). */
+#if GCC_VERSION >= 4003
+/* If asserts are disabled, activate -Wuninitialized as a warning (not
+ an error/-Werror). */
+#ifndef ENABLE_ASSERT_CHECKING
+#pragma GCC diagnostic warning "-Wuninitialized"
+#endif
+#endif
+
+#ifdef ENABLE_VALGRIND_CHECKING
+# ifdef HAVE_VALGRIND_MEMCHECK_H
+# include <valgrind/memcheck.h>
+# elif defined HAVE_MEMCHECK_H
+# include <memcheck.h>
+# else
+# include <valgrind.h>
+# endif
+/* Compatibility macros to let valgrind 3.1 work. */
+# ifndef VALGRIND_MAKE_MEM_NOACCESS
+# define VALGRIND_MAKE_MEM_NOACCESS VALGRIND_MAKE_NOACCESS
+# endif
+# ifndef VALGRIND_MAKE_MEM_DEFINED
+# define VALGRIND_MAKE_MEM_DEFINED VALGRIND_MAKE_READABLE
+# endif
+# ifndef VALGRIND_MAKE_MEM_UNDEFINED
+# define VALGRIND_MAKE_MEM_UNDEFINED VALGRIND_MAKE_WRITABLE
+# endif
+#else
+/* Avoid #ifdef:s when we can help it. */
+#define VALGRIND_DISCARD(x)
+#define VALGRIND_MALLOCLIKE_BLOCK(w,x,y,z)
+#define VALGRIND_FREELIKE_BLOCK(x,y)
+#endif
+