re PR sanitizer/84307 (asan blocks dead-store elimination)

gcc:
2018-02-12  Paolo Bonzini <bonzini@gnu.org>

	PR sanitizer/84307
	* internal-fn.def (ASAN_CHECK): Fix fnspec to account for return value.
	(ASAN_MARK): Fix fnspec to account for return value, change pointer
	argument from 'R' to 'W' so that the pointed-to datum is clobbered.

gcc/testsuite:
2018-02-12  Paolo Bonzini  <bonzini@gnu.org>

	PR sanitizer/84307
	* gcc.dg/asan/pr84307.c: New test.

From-SVN: r257585

gcc/ChangeLog

+2018-02-12  Paolo Bonzini <bonzini@gnu.org>
+
+	PR sanitizer/84307
+	* internal-fn.def (ASAN_CHECK): Fix fnspec to account for return value.
+	(ASAN_MARK): Fix fnspec to account for return value, change pointer
+	argument from 'R' to 'W' so that the pointed-to datum is clobbered.
+
 2018-02-08  Jan Hubicka  <hubicka@ucw.cz>
 
 	PR middle-end/83665

gcc/internal-fn.def

@@ -255,8 +255,8 @@ DEF_INTERNAL_FN (UBSAN_PTR, ECF_LEAF | ECF_NOTHROW, ".R.")
 DEF_INTERNAL_FN (UBSAN_OBJECT_SIZE, ECF_LEAF | ECF_NOTHROW, NULL)
 DEF_INTERNAL_FN (ABNORMAL_DISPATCHER, ECF_NORETURN, NULL)
 DEF_INTERNAL_FN (BUILTIN_EXPECT, ECF_CONST | ECF_LEAF | ECF_NOTHROW, NULL)
-DEF_INTERNAL_FN (ASAN_CHECK, ECF_TM_PURE | ECF_LEAF | ECF_NOTHROW, ".R...")
-DEF_INTERNAL_FN (ASAN_MARK, ECF_LEAF | ECF_NOTHROW, ".R..")
+DEF_INTERNAL_FN (ASAN_CHECK, ECF_TM_PURE | ECF_LEAF | ECF_NOTHROW, "..R..")
+DEF_INTERNAL_FN (ASAN_MARK, ECF_LEAF | ECF_NOTHROW, "..W.")
 DEF_INTERNAL_FN (ASAN_POISON, ECF_LEAF | ECF_NOTHROW | ECF_NOVOPS, NULL)
 DEF_INTERNAL_FN (ASAN_POISON_USE, ECF_LEAF | ECF_NOTHROW | ECF_NOVOPS, NULL)
 DEF_INTERNAL_FN (ADD_OVERFLOW, ECF_CONST | ECF_LEAF | ECF_NOTHROW, NULL)

gcc/testsuite/ChangeLog

+2018-02-12  Paolo Bonzini  <bonzini@gnu.org>
+
+	PR sanitizer/84307
+	* gcc.dg/asan/pr84307.c: New test.
+
 2018-02-12  Nathan Sidwell  <nathan@acm.org>
 
 	* g++.dg/parse/pr84263.C: New.

gcc/testsuite/gcc.dg/asan/pr84307.c

+/* PR middle-end/83185 */
+/* { dg-do link } */
+/* { dg-options "-O1" } */
+
+struct f {
+  void (*func)(void);
+};
+
+extern void link_error(void);
+extern int printf(const char *f, ...);
+
+static inline struct f *gimme_null(struct f *result)
+{
+  return 0;
+}
+
+int main(int argc, char **argv)
+{
+  struct f *x = gimme_null(&(struct f) { .func = link_error });
+  printf("%p", x);
+}