PR tree-optimization/91914 - Invalid strlen folding for offset into struct

gcc/testsuite/CHangeLog:
	* gcc.dg/strlenopt-79.c: New test.

From-SVN: r276156

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 2323593045023b6107e2ed794ea66eabeb7a4c16..8d75c29feb1f772f1c1187520588b2cd566edbb5 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2019-09-26  Martin Sebor  <msebor@redhat.com>
+
+       PR tree-optimization/91914
+       * gcc.dg/strlenopt-79.c: New test.
+
 2019-09-26  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
 
        * gcc.target/arm/acle/simd32.c: Update test.

diff --git a/gcc/testsuite/gcc.dg/strlenopt-79.c b/gcc/testsuite/gcc.dg/strlenopt-79.c
new file mode 100644 (file)
index 0000000..362cbfb
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/strlenopt-79.c
@@ -0,0 +1,46 @@
+/* PR tree-optimization/91914 - Invalid strlen folding for offset into struct
+   { dg-do run }
+   { dg-options "-O2 -Wall" } */
+
+#define assert(expr)                                           \
+  ((expr)                                                      \
+   ? (void)0                                                   \
+   : (__builtin_printf ("%s:%i: assertion failed: %s\n",       \
+                       __FILE__, __LINE__, #expr),             \
+      __builtin_abort ()))
+
+extern __SIZE_TYPE__ strlen (const char*);
+
+struct stringpool_t
+{
+  char s1[sizeof ("1")];
+  char s2[sizeof ("12")];
+  char s3[sizeof ("123")];
+  char s4[sizeof ("1234")];
+  char s5[sizeof ("12345")];
+};
+
+static const struct stringpool_t stringpool_contents =
+  {
+   "1", "12", "123", "1234", "12345"
+  };
+
+#define stringpool ((const char *) &stringpool_contents)
+
+volatile int i0 = 0, i2 = 2, i5 = 5, i9 = 9, i14 = 14;
+
+int main (void)
+{
+  /* These shouldn't trigger warnings.  */
+  assert (strlen (stringpool) == 1);
+  assert (strlen (stringpool + 2) == 2);
+  assert (strlen (stringpool + 5) == 3);
+  assert (strlen (stringpool + 9) == 4);
+  assert (strlen (stringpool + 14) == 5);
+
+  assert (strlen (stringpool + i0) == 1);
+  assert (strlen (stringpool + i2) == 2);
+  assert (strlen (stringpool + i5) == 3);
+  assert (strlen (stringpool + i9) == 4);
+  assert (strlen (stringpool + i14) == 5);
+}