diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 6e05c969993..d443cb45ed4 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,10 @@
 2020-03-17  Jakub Jelinek  <jakub@redhat.com>
 
+	PR middle-end/94189
+	* builtins.c (expand_builtin_strnlen): Do return NULL_RTX if we would
+	emit a warning if it was enabled and don't depend on TREE_NO_WARNING
+	for code-generation.
+
 	Backported from mainline
 	2020-03-16  Jakub Jelinek  <jakub@redhat.com>
 
diff --git a/gcc/builtins.c b/gcc/builtins.c
index ed11f79ff0b..e8e43f53ec6 100644
--- a/gcc/builtins.c
+++ b/gcc/builtins.c
@@ -3112,27 +3112,25 @@ expand_builtin_strnlen (tree exp, rtx target, machine_mode target_mode)
 	    return NULL_RTX;
 	}
 
-      if (lendata.decl
-	  && !TREE_NO_WARNING (exp)
-	  && ((tree_int_cst_lt (len, bound))
-	      || !exact))
+      if (lendata.decl && (tree_int_cst_lt (len, bound) || !exact))
 	{
 	  location_t warnloc
 	    = expansion_point_location_if_in_system_header (loc);
 
-	  if (warning_at (warnloc, OPT_Wstringop_overflow_,
-			  exact
-			  ? G_("%K%qD specified bound %E exceeds the size %E "
-			       "of unterminated array")
-			  : G_("%K%qD specified bound %E may exceed the size "
-			       "of at most %E of unterminated array"),
-			  exp, func, bound, len))
+	  if (!TREE_NO_WARNING (exp)
+	      && warning_at (warnloc, OPT_Wstringop_overflow_,
+			     exact
+			     ? G_("%K%qD specified bound %E exceeds the size "
+				  "%E of unterminated array")
+			     : G_("%K%qD specified bound %E may exceed the "
+				  "size of at most %E of unterminated array"),
+			     exp, func, bound, len))
 	    {
 	      inform (DECL_SOURCE_LOCATION (lendata.decl),
 		      "referenced argument declared here");
 	      TREE_NO_WARNING (exp) = true;
-	      return NULL_RTX;
 	    }
+	  return NULL_RTX;
 	}
 
       if (!len)
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 522a7608203..f982ee6a9ec 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,8 @@
 2020-03-17  Jakub Jelinek  <jakub@redhat.com>
 
+	PR middle-end/94189
+	* gcc.dg/pr94189.c: New test.
+
 	Backported from mainline
 	2020-03-16  Jakub Jelinek  <jakub@redhat.com>
 
diff --git a/gcc/testsuite/gcc.dg/pr94189.c b/gcc/testsuite/gcc.dg/pr94189.c
new file mode 100644
index 00000000000..f927d55279a
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr94189.c
@@ -0,0 +1,11 @@
+/* PR middle-end/94189 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -fcompare-debug" } */
+
+const char a[] = { 'a', 'b', 'c', 'd' };/* { dg-message "declared here" } */
+
+int
+foo (void)
+{
+  return __builtin_strnlen (a, 5);	/* { dg-warning "specified bound 5 exceeds the size 4 of unterminated array" } */
+}