Avoid "implicit fallthrough" warnings also from clang.

10 files changed, 72 insertions, 56 deletions

diff --git a/ChangeLog b/ChangeLog
index 023d3bc..268d5c7 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,21 @@
 2018-09-08  Bruno Haible  <bruno@clisp.org>
 
+	Avoid "implicit fallthrough" warnings also from clang.
+	Reported by Nico Weber <thakis@chromium.org> in
+	<https://savannah.gnu.org/bugs/?53029>.
+	Clang emits these warnings in C++11 mode only, see
+	<https://clang.llvm.org/docs/AttributeReference.html#fallthrough>,
+	and only in clang 3.9 or newer, see
+	<http://releases.llvm.org/3.9.0/tools/clang/docs/ReleaseNotes.html>.
+	To avoid them, either [[fallthrough]] or the (nearly equivalent) older
+	[[clang::fallthrough]] can be used, see
+	<http://llvm.org/viewvc/llvm-project?view=revision&revision=262881>.
+	* src/output.cc (Output::output_hash_function): Enhance the fallthrough
+	marker.
+	* tests/*.exp: Update.
+
+2018-09-08  Bruno Haible  <bruno@clisp.org>
+
 	Fix failure of "make check -j2".
 	Reported and fix provided by Bernhard M. Wiedemann in
 	<https://savannah.gnu.org/bugs/?53208>.
diff --git a/src/output.cc b/src/output.cc
index 2539fde..5c62828 100644
--- a/src/output.cc
+++ b/src/output.cc
@@ -937,7 +937,7 @@ Output::output_hash_function () const
           /* Pseudo-statement or comment that avoids a compiler warning or
              lint warning.  */
           const char * const fallthrough_marker =
-            "#if defined __cplusplus && __cplusplus >= 201703L\n"
+            "#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))\n"
             "      [[fallthrough]];\n"
             "#elif defined __GNUC__ && __GNUC__ >= 7\n"
             "      __attribute__ ((__fallthrough__));\n"
diff --git a/tests/c-parse.exp b/tests/c-parse.exp
index d88878c..9294294 100644
--- a/tests/c-parse.exp
+++ b/tests/c-parse.exp
@@ -86,7 +86,7 @@ hash (str, len)
     {
       default:
         hval += asso_values[(unsigned char)str[2]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
diff --git a/tests/charsets.exp b/tests/charsets.exp
index 4af888f..afc8b88 100644
--- a/tests/charsets.exp
+++ b/tests/charsets.exp
@@ -93,7 +93,7 @@ hash (register const char *str, register size_t len)
     {
       default:
         hval += asso_values[(unsigned char)str[21]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -111,7 +111,7 @@ hash (register const char *str, register size_t len)
       case 12:
       case 11:
         hval += asso_values[(unsigned char)str[10]+1];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -119,7 +119,7 @@ hash (register const char *str, register size_t len)
       /*FALLTHROUGH*/
       case 10:
         hval += asso_values[(unsigned char)str[9]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -127,7 +127,7 @@ hash (register const char *str, register size_t len)
       /*FALLTHROUGH*/
       case 9:
         hval += asso_values[(unsigned char)str[8]+1];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -135,7 +135,7 @@ hash (register const char *str, register size_t len)
       /*FALLTHROUGH*/
       case 8:
         hval += asso_values[(unsigned char)str[7]+3];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -143,7 +143,7 @@ hash (register const char *str, register size_t len)
       /*FALLTHROUGH*/
       case 7:
         hval += asso_values[(unsigned char)str[6]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -151,7 +151,7 @@ hash (register const char *str, register size_t len)
       /*FALLTHROUGH*/
       case 6:
         hval += asso_values[(unsigned char)str[5]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -159,7 +159,7 @@ hash (register const char *str, register size_t len)
       /*FALLTHROUGH*/
       case 5:
         hval += asso_values[(unsigned char)str[4]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -167,7 +167,7 @@ hash (register const char *str, register size_t len)
       /*FALLTHROUGH*/
       case 4:
         hval += asso_values[(unsigned char)str[3]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -175,7 +175,7 @@ hash (register const char *str, register size_t len)
       /*FALLTHROUGH*/
       case 3:
         hval += asso_values[(unsigned char)str[2]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -183,7 +183,7 @@ hash (register const char *str, register size_t len)
       /*FALLTHROUGH*/
       case 2:
         hval += asso_values[(unsigned char)str[1]+1];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
diff --git a/tests/chill.exp b/tests/chill.exp
index 3fc858a..4f7e373 100644
--- a/tests/chill.exp
+++ b/tests/chill.exp
@@ -84,7 +84,7 @@ hash (str, len)
     {
       default:
         hval += asso_values[(unsigned char)str[29]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -92,7 +92,7 @@ hash (str, len)
       /*FALLTHROUGH*/
       case 29:
         hval += asso_values[(unsigned char)str[28]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -100,7 +100,7 @@ hash (str, len)
       /*FALLTHROUGH*/
       case 28:
         hval += asso_values[(unsigned char)str[27]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -108,7 +108,7 @@ hash (str, len)
       /*FALLTHROUGH*/
       case 27:
         hval += asso_values[(unsigned char)str[26]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -116,7 +116,7 @@ hash (str, len)
       /*FALLTHROUGH*/
       case 26:
         hval += asso_values[(unsigned char)str[25]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -124,7 +124,7 @@ hash (str, len)
       /*FALLTHROUGH*/
       case 25:
         hval += asso_values[(unsigned char)str[24]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -132,7 +132,7 @@ hash (str, len)
       /*FALLTHROUGH*/
       case 24:
         hval += asso_values[(unsigned char)str[23]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -140,7 +140,7 @@ hash (str, len)
       /*FALLTHROUGH*/
       case 23:
         hval += asso_values[(unsigned char)str[22]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -148,7 +148,7 @@ hash (str, len)
       /*FALLTHROUGH*/
       case 22:
         hval += asso_values[(unsigned char)str[21]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -156,7 +156,7 @@ hash (str, len)
       /*FALLTHROUGH*/
       case 21:
         hval += asso_values[(unsigned char)str[20]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -164,7 +164,7 @@ hash (str, len)
       /*FALLTHROUGH*/
       case 20:
         hval += asso_values[(unsigned char)str[19]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -172,7 +172,7 @@ hash (str, len)
       /*FALLTHROUGH*/
       case 19:
         hval += asso_values[(unsigned char)str[18]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -180,7 +180,7 @@ hash (str, len)
       /*FALLTHROUGH*/
       case 18:
         hval += asso_values[(unsigned char)str[17]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -188,7 +188,7 @@ hash (str, len)
       /*FALLTHROUGH*/
       case 17:
         hval += asso_values[(unsigned char)str[16]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -196,7 +196,7 @@ hash (str, len)
       /*FALLTHROUGH*/
       case 16:
         hval += asso_values[(unsigned char)str[15]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -204,7 +204,7 @@ hash (str, len)
       /*FALLTHROUGH*/
       case 15:
         hval += asso_values[(unsigned char)str[14]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -212,7 +212,7 @@ hash (str, len)
       /*FALLTHROUGH*/
       case 14:
         hval += asso_values[(unsigned char)str[13]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -220,7 +220,7 @@ hash (str, len)
       /*FALLTHROUGH*/
       case 13:
         hval += asso_values[(unsigned char)str[12]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -228,7 +228,7 @@ hash (str, len)
       /*FALLTHROUGH*/
       case 12:
         hval += asso_values[(unsigned char)str[11]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -236,7 +236,7 @@ hash (str, len)
       /*FALLTHROUGH*/
       case 11:
         hval += asso_values[(unsigned char)str[10]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -244,7 +244,7 @@ hash (str, len)
       /*FALLTHROUGH*/
       case 10:
         hval += asso_values[(unsigned char)str[9]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -252,7 +252,7 @@ hash (str, len)
       /*FALLTHROUGH*/
       case 9:
         hval += asso_values[(unsigned char)str[8]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -260,7 +260,7 @@ hash (str, len)
       /*FALLTHROUGH*/
       case 8:
         hval += asso_values[(unsigned char)str[7]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -268,7 +268,7 @@ hash (str, len)
       /*FALLTHROUGH*/
       case 7:
         hval += asso_values[(unsigned char)str[6]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -276,7 +276,7 @@ hash (str, len)
       /*FALLTHROUGH*/
       case 6:
         hval += asso_values[(unsigned char)str[5]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -284,7 +284,7 @@ hash (str, len)
       /*FALLTHROUGH*/
       case 5:
         hval += asso_values[(unsigned char)str[4]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -292,7 +292,7 @@ hash (str, len)
       /*FALLTHROUGH*/
       case 4:
         hval += asso_values[(unsigned char)str[3]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -300,7 +300,7 @@ hash (str, len)
       /*FALLTHROUGH*/
       case 3:
         hval += asso_values[(unsigned char)str[2]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -308,7 +308,7 @@ hash (str, len)
       /*FALLTHROUGH*/
       case 2:
         hval += asso_values[(unsigned char)str[1]+1];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
diff --git a/tests/cplusplus.exp b/tests/cplusplus.exp
index 20c4471..3e4f181 100644
--- a/tests/cplusplus.exp
+++ b/tests/cplusplus.exp
@@ -86,7 +86,7 @@ hash (str, len)
     {
       default:
         hval += asso_values[(unsigned char)str[6]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -96,7 +96,7 @@ hash (str, len)
       case 5:
       case 4:
         hval += asso_values[(unsigned char)str[3]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
diff --git a/tests/java.exp b/tests/java.exp
index 7176106..bce452b 100644
--- a/tests/java.exp
+++ b/tests/java.exp
@@ -110,7 +110,7 @@ hash (str, len)
     {
       default:
         hval += asso_values[(unsigned char)str[2]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
diff --git a/tests/languages.exp b/tests/languages.exp
index 36d36d7..88b84c7 100644
--- a/tests/languages.exp
+++ b/tests/languages.exp
@@ -97,7 +97,7 @@ hash (register const char *str, register size_t len)
     {
       default:
         hval += asso_values[(unsigned char)str[4]+1];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -106,7 +106,7 @@ hash (register const char *str, register size_t len)
       case 4:
       case 3:
         hval += asso_values[(unsigned char)str[2]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -114,7 +114,7 @@ hash (register const char *str, register size_t len)
       /*FALLTHROUGH*/
       case 2:
         hval += asso_values[(unsigned char)str[1]+9];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
diff --git a/tests/modula2.exp b/tests/modula2.exp
index 658223b..4a622fd 100644
--- a/tests/modula2.exp
+++ b/tests/modula2.exp
@@ -81,7 +81,7 @@ hash (register const char *str, register size_t len)
     {
       default:
         hval += asso_values[(unsigned char)str[7]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -89,7 +89,7 @@ hash (register const char *str, register size_t len)
       /*FALLTHROUGH*/
       case 7:
         hval += asso_values[(unsigned char)str[6]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -97,7 +97,7 @@ hash (register const char *str, register size_t len)
       /*FALLTHROUGH*/
       case 6:
         hval += asso_values[(unsigned char)str[5]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -105,7 +105,7 @@ hash (register const char *str, register size_t len)
       /*FALLTHROUGH*/
       case 5:
         hval += asso_values[(unsigned char)str[4]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -113,7 +113,7 @@ hash (register const char *str, register size_t len)
       /*FALLTHROUGH*/
       case 4:
         hval += asso_values[(unsigned char)str[3]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -121,7 +121,7 @@ hash (register const char *str, register size_t len)
       /*FALLTHROUGH*/
       case 3:
         hval += asso_values[(unsigned char)str[2]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
@@ -129,7 +129,7 @@ hash (register const char *str, register size_t len)
       /*FALLTHROUGH*/
       case 2:
         hval += asso_values[(unsigned char)str[1]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));
diff --git a/tests/objc.exp b/tests/objc.exp
index 379e668..3d7b16c 100644
--- a/tests/objc.exp
+++ b/tests/objc.exp
@@ -84,7 +84,7 @@ hash (register const char *str, register size_t len)
     {
       default:
         hval += asso_values[(unsigned char)str[2]];
-#if defined __cplusplus && __cplusplus >= 201703L
+#if defined __cplusplus && (__cplusplus >= 201703L || (__cplusplus >= 201103L && defined __clang_major__ && defined __clang_minor__ && __clang_major__ + (__clang_minor__ >= 9) > 3))
       [[fallthrough]];
 #elif defined __GNUC__ && __GNUC__ >= 7
       __attribute__ ((__fallthrough__));