PR tree-optimization/99489 - ICE calling strncat after strcat

gcc/ChangeLog:

	PR tree-optimization/99489
	* builtins.c (gimple_call_alloc_size): Fail gracefully when argument
	is not a call statement.

gcc/testsuite/ChangeLog:

	PR tree-optimization/99489
	* gcc.dg/Wstringop-truncation-9.c: New test.

diff --git a/gcc/builtins.c b/gcc/builtins.c
index 41e336c071c..196dda3fa5e 100644
--- a/gcc/builtins.c
+++ b/gcc/builtins.c
@@ -4924,7 +4924,7 @@ tree
 gimple_call_alloc_size (gimple *stmt, wide_int rng1[2] /* = NULL */,
 			range_query * /* = NULL */)
 {
-  if (!stmt)
+  if (!stmt || !is_gimple_call (stmt))
     return NULL_TREE;
 
   tree allocfntype;
diff --git a/gcc/testsuite/gcc.dg/Wstringop-truncation-9.c b/gcc/testsuite/gcc.dg/Wstringop-truncation-9.c
new file mode 100644
index 00000000000..63614809da4
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/Wstringop-truncation-9.c
@@ -0,0 +1,41 @@
+/* PR tree-optimization/99489 - ICE calling strncat after strncat
+   { dg-do compile }
+   { dg-options "-O2 -Wall" } */
+
+// Important -- see pr82429.
+char *stpcpy (char *, const char *);
+
+void fchar (char *d, char c, char *s)
+{
+  __builtin_strcat (d, s);
+  __builtin_strncat (d, &c, 1);
+}
+
+void fcstchar (char *d, char *s)
+{
+  __builtin_strcat (d, s);
+
+  const char c = 'x';
+  __builtin_strncat (d, &c, 1);     // { dg-warning "-Wstringop-truncation" }
+}
+
+void fstr (char *d, char *s)
+{
+  __builtin_strcat (d, s);
+  __builtin_strncat (d, s, 1);
+}
+
+void farr (char *d, char *s)
+{
+  __builtin_strcat (d, s);
+
+  char a[] = "x";
+  __builtin_strncat (d, a, 1);      // { dg-warning "-Wstringop-truncation" }
+}
+
+void flit (char *d, char *s)
+{
+  __builtin_strcat (d, s);
+  __builtin_strncat (d, "x", 1);    // { dg-warning "-Wstringop-truncation" "pr?????" { xfail *-*-*} }
+                                    // { dg-warning "-Wstringop-overflow" "actual" { target *-*-*} .-1 }
+}