[gcc/devel/ranger] Add new test for PR tree-optimization/92982.

[Aldy Hernandez]

https://gcc.gnu.org/g:f26688fbe441375e907f0dd2f35837681870b1f4

commit f26688fbe441375e907f0dd2f35837681870b1f4
Author: Martin Sebor <msebor@redhat.com>
Date:   Mon Mar 2 11:49:01 2020 -0700

    Add new test for PR tree-optimization/92982.
    
    gcc/testsuite/ChangeLog:
            PR tree-optimization/92982
            * gcc.dg/strlenopt-94.c: New test.

Diff:
---
 gcc/testsuite/ChangeLog             |  5 +++++
 gcc/testsuite/gcc.dg/strlenopt-94.c | 28 ++++++++++++++++++++++++++++
 2 files changed, 33 insertions(+)

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 79fe37d5a17..e18c6a9f7a6 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2020-03-02  Martin Sebor  <msebor@redhat.com>
+
+	PR tree-optimization/92982
+	* gcc.dg/strlenopt-94.c: New test.
+
 2020-03-02  Iain Sandoe  <iain@sandoe.co.uk>
 
 	* g++.dg/coroutines/torture/func-params-09-awaitable-parms.C: New test.
diff --git a/gcc/testsuite/gcc.dg/strlenopt-94.c b/gcc/testsuite/gcc.dg/strlenopt-94.c
new file mode 100644
index 00000000000..c2a23d35881
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/strlenopt-94.c
@@ -0,0 +1,28 @@
+/* PR tree-optimization/93982 - Assignment incorrectly omitted by
+   -foptimize-strlen
+   { dg-do run }
+   { dg-options "-O2 -Wall" } */
+
+struct A { const char **a; };
+const char *buf[5];
+
+__attribute__((noipa)) struct A
+foo (char *p)
+{
+  struct A r = { (const char **) p };
+  r.a[0] = "12345678";
+  r.a[1] = "";
+  r.a[2] = "";
+  r.a[3] = "";
+  r.a[4] = "";
+  return r;
+}
+
+int
+main ()
+{
+  struct A r = foo ((char *) &buf[0]);
+  if (!r.a[1] || r.a[1][0] != '\0')
+    __builtin_abort ();
+  return 0;
+}