re PR tree-optimization/79715 (hand-rolled strdup with unused result not eliminated)

gcc/testsuite/ChangeLog:
	PR tree-optimization/79715
	* gcc.dg/pr79715.c: New test.

From-SVN: r247440

gcc/testsuite/ChangeLog

+2017-05-01  Martin Sebor  <msebor@redhat.com>
+
+	PR tree-optimization/79715
+	* gcc.dg/pr79715.c: New test.
+
 2017-05-01  Tom de Vries  <tom@codesourcery.com>
 
 	PR testsuite/65941

gcc/testsuite/gcc.dg/pr79715.c

+/* PR tree-optimization/79715 - hand-rolled strdup with unused result
+   not eliminated
+   { dg-do compile }
+   { dg-options "-O2 -Wall -fdump-tree-optimized" } */
+
+void f (const char *s)
+{
+  unsigned n = __builtin_strlen (s) + 1;
+  char *p = __builtin_malloc (n);
+  __builtin_memcpy (p, s, n);
+  __builtin_free (p);
+}
+
+void g (const char *s)
+{
+  unsigned n = __builtin_strlen (s) + 1;
+  char *p = __builtin_malloc (n);
+  __builtin_strcpy (p, s);
+  __builtin_free (p);
+}
+
+/* { dg-final { scan-tree-dump-not "free" "optimized" } }
+   { dg-final { scan-tree-dump-not "malloc" "optimized" } }
+   { dg-final { scan-tree-dump-not "memcpy" "optimized" } }
+   { dg-final { scan-tree-dump-not "strcpy" "optimized" } }
+   { dg-final { scan-tree-dump-not "strlen" "optimized" } } */