Add a test to verify we pre-allocated enough hf entries.

This way we'll know as soon as we drop below the pre-allocated limit. As
suggested by Graham on https://code.wireshark.org/review/10601

Change-Id: Ieeb14bdcf991d7a67c30787c97ca24ebb35d1763
Reviewed-on: https://code.wireshark.org/review/10627
Reviewed-by: Alexis La Goutte <alexis.lagoutte@gmail.com>

epan/proto.c

@@ -7809,8 +7809,11 @@ proto_registrar_dump_values(void)
 /* Prints the number of registered fields.
  * Useful for determining an appropriate value for
  * PROTO_PRE_ALLOC_HF_FIELDS_MEM.
+ *
+ * Returns FALSE if PROTO_PRE_ALLOC_HF_FIELDS_MEM is larger than or equal to
+ * the number of fields, TRUE otherwise.
  */
-void
+gboolean
 proto_registrar_dump_fieldcount(void)
 {
 	guint32			i;
@@ -7834,17 +7837,24 @@ proto_registrar_dump_fieldcount(void)
 			same_name_count++;
 	}
 
-	printf("There are %d header fields registered, of which:\n"
-	       "\t%d are deregistered\n"
-	       "\t%d are protocols\n"
-	       "\t%d have the same name as another field\n\n",
+	printf ("There are %d header fields registered, of which:\n"
+		"\t%d are deregistered\n"
+		"\t%d are protocols\n"
+		"\t%d have the same name as another field\n\n",
 		gpa_hfinfo.len, deregistered_count, protocol_count,
 		same_name_count);
 
-	printf("The header field table consumes %d KiB of memory.\n",
-	       (int)(gpa_hfinfo.allocated_len * sizeof(header_field_info *) / 1024));
-	printf("The fields themselves consume %d KiB of memory.\n",
-	       (int)(gpa_hfinfo.len * sizeof(header_field_info) / 1024));
+	printf ("%d fields were pre-allocated.\n%s", PROTO_PRE_ALLOC_HF_FIELDS_MEM,
+		(gpa_hfinfo.allocated_len > PROTO_PRE_ALLOC_HF_FIELDS_MEM) ?
+		    "* * Please increase PROTO_PRE_ALLOC_HF_FIELDS_MEM (in epan/proto.c)! * *\n\n" :
+		    "\n");
+
+	printf ("The header field table consumes %d KiB of memory.\n",
+		(int)(gpa_hfinfo.allocated_len * sizeof(header_field_info *) / 1024));
+	printf ("The fields themselves consume %d KiB of memory.\n",
+		(int)(gpa_hfinfo.len * sizeof(header_field_info) / 1024));
+
+	return (gpa_hfinfo.allocated_len > PROTO_PRE_ALLOC_HF_FIELDS_MEM);
 }
 
 

epan/proto.h

@@ -2251,8 +2251,9 @@ WS_DLL_PUBLIC void proto_registrar_dump_protocols(void);
 /** Dumps a glossary of the field value strings or true/false strings to STDOUT */
 WS_DLL_PUBLIC void proto_registrar_dump_values(void);
 
-/** Dumps the number of protocol and field registrations to STDOUT. */
-WS_DLL_PUBLIC void proto_registrar_dump_fieldcount(void);
+/** Dumps the number of protocol and field registrations to STDOUT.
+ @return FALSE if we pre-allocated enough fields, TRUE otherwise. */
+WS_DLL_PUBLIC gboolean proto_registrar_dump_fieldcount(void);
 
 /** Dumps a glossary of the protocol and field registrations to STDOUT. */
 WS_DLL_PUBLIC void proto_registrar_dump_fields(void);

test/suite-unittests.sh

@@ -100,6 +100,12 @@ unittests_step_ftsanity() {
 	unittests_step_test
 }
 
+unittests_step_fieldcount() {
+	check_dut tshark
+	ARGS="-G fieldcount"
+	unittests_step_test
+}
+
 unittests_cleanup_step() {
 	rm -f ./testout.txt
 }
@@ -113,6 +119,7 @@ unittests_suite() {
 	test_step_add "tvbtest" unittests_step_tvbtest
 	test_step_add "wmem_test" unittests_step_wmem_test
 	test_step_add "ftsanity.py" unittests_step_ftsanity
+	test_step_add "field count" unittests_step_fieldcount
 }
 #
 # Editor modelines  -  http://www.wireshark.org/tools/modelines.html

tshark.c

@@ -1276,9 +1276,10 @@ DIAG_ON(cast-qual)
         write_prefs(NULL);
       else if (strcmp(argv[2], "dissector-tables") == 0)
         dissector_dump_dissector_tables();
-      else if (strcmp(argv[2], "fieldcount") == 0)
-        proto_registrar_dump_fieldcount();
-      else if (strcmp(argv[2], "fields") == 0)
+      else if (strcmp(argv[2], "fieldcount") == 0) {
+        /* return value for the test suite */
+        return proto_registrar_dump_fieldcount();
+      } else if (strcmp(argv[2], "fields") == 0)
         proto_registrar_dump_fields();
       else if (strcmp(argv[2], "ftypes") == 0)
         proto_registrar_dump_ftypes();