dfilter: Remove existence test syntax tree nodes

After some experimentation I don't think these two existence tests
belong in the grammar, it's an implementation detail and removing it
might avoid some artificial constraints.

5 files changed, 55 insertions, 68 deletions

diff --git a/epan/dfilter/gencode.c b/epan/dfilter/gencode.c
index 2674417a10..d68ef697e2 100644
--- a/epan/dfilter/gencode.c
+++ b/epan/dfilter/gencode.c
@@ -430,6 +430,47 @@ gen_entity(dfwork_t *dfw, stnode_t *st_arg, GSList **jumps_ptr)
 	return val;
 }
 
+static void
+gen_exists(dfwork_t *dfw, stnode_t *st_node)
+{
+	dfvm_insn_t *insn;
+	header_field_info *hfinfo;
+
+	hfinfo = stnode_data(st_node);
+
+	/* Rewind to find the first field of this name. */
+	while (hfinfo->same_name_prev_id != -1) {
+		hfinfo = proto_registrar_get_nth(hfinfo->same_name_prev_id);
+	}
+	insn = dfvm_insn_new(CHECK_EXISTS);
+	insn->arg1 = dfvm_value_new_hfinfo(hfinfo);
+	dfw_append_insn(dfw, insn);
+
+	/* Record the FIELD_ID in hash of interesting fields. */
+	while (hfinfo) {
+		g_hash_table_insert(dfw->interesting_fields,
+			GINT_TO_POINTER(hfinfo->id),
+			GUINT_TO_POINTER(TRUE));
+		hfinfo = hfinfo->same_name_next;
+	}
+}
+
+static void
+gen_notzero(dfwork_t *dfw, stnode_t *st_node)
+{
+	dfvm_insn_t	*insn;
+	dfvm_value_t	*val1;
+	GSList		*jumps = NULL;
+
+	val1 = gen_arithmetic(dfw, st_node, &jumps);
+	insn = dfvm_insn_new(ALL_ZERO);
+	insn->arg1 = dfvm_value_ref(val1);
+	dfw_append_insn(dfw, insn);
+	insn = dfvm_insn_new(NOT);
+	dfw_append_insn(dfw, insn);
+	g_slist_foreach(jumps, fixup_jumps, dfw);
+	g_slist_free(jumps);
+}
 
 static void
 gen_test(dfwork_t *dfw, stnode_t *st_node)
@@ -437,10 +478,8 @@ gen_test(dfwork_t *dfw, stnode_t *st_node)
 	test_op_t	st_op;
 	stnode_t	*st_arg1, *st_arg2;
 	dfvm_insn_t	*insn;
-	dfvm_value_t	*jmp, *val1;
-	GSList		*jumps = NULL;
+	dfvm_value_t	*jmp;
 
-	header_field_info	*hfinfo;
 
 	sttype_test_get(st_node, &st_op, &st_arg1, &st_arg2);
 
@@ -449,39 +488,6 @@ gen_test(dfwork_t *dfw, stnode_t *st_node)
 			ws_assert_not_reached();
 			break;
 
-		case TEST_OP_EXISTS:
-			hfinfo = stnode_data(st_arg1);
-
-			/* Rewind to find the first field of this name. */
-			while (hfinfo->same_name_prev_id != -1) {
-				hfinfo = proto_registrar_get_nth(hfinfo->same_name_prev_id);
-			}
-			insn = dfvm_insn_new(CHECK_EXISTS);
-			insn->arg1 = dfvm_value_new_hfinfo(hfinfo);
-			dfw_append_insn(dfw, insn);
-
-			/* Record the FIELD_ID in hash of interesting fields. */
-			while (hfinfo) {
-				g_hash_table_insert(dfw->interesting_fields,
-					GINT_TO_POINTER(hfinfo->id),
-					GUINT_TO_POINTER(TRUE));
-				hfinfo = hfinfo->same_name_next;
-			}
-
-			break;
-
-		case TEST_OP_NOTZERO:
-			val1 = gen_entity(dfw, st_arg1, &jumps);
-			insn = dfvm_insn_new(ALL_ZERO);
-			insn->arg1 = dfvm_value_ref(val1);
-			dfw_append_insn(dfw, insn);
-			insn = dfvm_insn_new(NOT);
-			dfw_append_insn(dfw, insn);
-			g_slist_foreach(jumps, fixup_jumps, dfw);
-			g_slist_free(jumps);
-			jumps = NULL;
-			break;
-
 		case TEST_OP_NOT:
 			gencode(dfw, st_arg1);
 			insn = dfvm_insn_new(NOT);
@@ -575,6 +581,12 @@ gencode(dfwork_t *dfw, stnode_t *st_node)
 		case STTYPE_TEST:
 			gen_test(dfw, st_node);
 			break;
+		case STTYPE_FIELD:
+			gen_exists(dfw, st_node);
+			break;
+		case STTYPE_ARITHMETIC:
+			gen_notzero(dfw, st_node);
+			break;
 		default:
 			ws_assert_not_reached();
 	}
diff --git a/epan/dfilter/grammar.lemon b/epan/dfilter/grammar.lemon
index 78646f3dcc..7f6ac3857a 100644
--- a/epan/dfilter/grammar.lemon
+++ b/epan/dfilter/grammar.lemon
@@ -123,14 +123,12 @@ logical_test(T) ::= TEST_NOT(L) expr(E).
 
 logical_test(T) ::= entity(E).
 {
-    T = new_test(dfw, TEST_OP_EXISTS, NULL);
-    sttype_test_set1_args(T, E);
+    T = E;
 }
 
 logical_test(T) ::= arithmetic_term(E).
 {
-    T = new_test(dfw, TEST_OP_NOTZERO, NULL);
-    sttype_test_set1_args(T, E);
+    T = E;
 }
 
 
diff --git a/epan/dfilter/semcheck.c b/epan/dfilter/semcheck.c
index ff176e179c..6798e9d457 100644
--- a/epan/dfilter/semcheck.c
+++ b/epan/dfilter/semcheck.c
@@ -470,6 +470,7 @@ check_exists(dfwork_t *dfw, stnode_t *st_arg1)
 
 	switch (stnode_type_id(st_arg1)) {
 		case STTYPE_FIELD:
+		case STTYPE_ARITHMETIC:
 			/* This is OK */
 			break;
 		case STTYPE_REFERENCE:
@@ -477,7 +478,6 @@ check_exists(dfwork_t *dfw, stnode_t *st_arg1)
 		case STTYPE_UNPARSED:
 		case STTYPE_LITERAL:
 		case STTYPE_CHARCONST:
-		case STTYPE_ARITHMETIC:
 			FAIL(dfw, "%s is neither a field nor a protocol name.",
 					stnode_todisplay(st_arg1));
 			break;
@@ -1136,14 +1136,6 @@ check_test(dfwork_t *dfw, stnode_t *st_node)
 			ws_assert_not_reached();
 			break;
 
-		case TEST_OP_EXISTS:
-			check_exists(dfw, st_arg1);
-			break;
-
-		case TEST_OP_NOTZERO:
-			check_arithmetic_operation(dfw, st_arg1, FT_NONE);
-			break;
-
 		case TEST_OP_NOT:
 			semcheck(dfw, st_arg1);
 			break;
@@ -1316,14 +1308,15 @@ semcheck(dfwork_t *dfw, stnode_t *st_node)
 {
 	LOG_NODE(st_node);
 
-	/* The parser assures that the top-most syntax-tree
-	 * node will be a TEST node, no matter what. So assert that. */
 	switch (stnode_type_id(st_node)) {
 		case STTYPE_TEST:
 			check_test(dfw, st_node);
 			break;
+		case STTYPE_ARITHMETIC:
+			check_arithmetic_operation(dfw, st_node, FT_NONE);
+			break;
 		default:
-			ws_assert_not_reached();
+			check_exists(dfw, st_node);
 	}
 }
 
diff --git a/epan/dfilter/sttype-test.c b/epan/dfilter/sttype-test.c
index 9e08de8374..13c0040ee3 100644
--- a/epan/dfilter/sttype-test.c
+++ b/epan/dfilter/sttype-test.c
@@ -70,9 +70,6 @@ test_todisplay(test_op_t op)
 	const char *s = "<notset>";
 
 	switch(op) {
-		case TEST_OP_EXISTS:
-			s = "<exists>";
-			break;
 		case TEST_OP_NOT:
 			s = "!";
 			break;
@@ -125,9 +122,6 @@ test_todisplay(test_op_t op)
 		case OP_MODULO:
 			s = "%";
 			break;
-		case TEST_OP_NOTZERO:
-			s = "<notzero>";
-			break;
 		case TEST_OP_CONTAINS:
 			s = "contains";
 			break;
@@ -150,9 +144,6 @@ test_todebug(test_op_t op)
 	const char *s = "<notset>";
 
 	switch(op) {
-		case TEST_OP_EXISTS:
-			s = "TEST_EXISTS";
-			break;
 		case TEST_OP_NOT:
 			s = "TEST_NOT";
 			break;
@@ -207,9 +198,6 @@ test_todebug(test_op_t op)
 		case OP_MODULO:
 			s = "OP_MODULO";
 			break;
-		case TEST_OP_NOTZERO:
-			s = "TEST_NOTZERO";
-			break;
 		case TEST_OP_CONTAINS:
 			s = "TEST_CONTAINS";
 			break;
@@ -246,9 +234,7 @@ num_operands(test_op_t op)
 	switch(op) {
 		case TEST_OP_UNINITIALIZED:
 			break;
-		case TEST_OP_EXISTS:
 		case TEST_OP_NOT:
-		case TEST_OP_NOTZERO:
 		case OP_UNARY_MINUS:
 			return 1;
 		case TEST_OP_AND:
diff --git a/epan/dfilter/syntax-tree.h b/epan/dfilter/syntax-tree.h
index 3fa27841d1..d7bdce55d5 100644
--- a/epan/dfilter/syntax-tree.h
+++ b/epan/dfilter/syntax-tree.h
@@ -39,7 +39,6 @@ typedef enum {
 
 typedef enum {
 	TEST_OP_UNINITIALIZED,
-	TEST_OP_EXISTS,
 	TEST_OP_NOT,
 	TEST_OP_AND,
 	TEST_OP_OR,
@@ -58,7 +57,6 @@ typedef enum {
 	OP_MULTIPLY,
 	OP_DIVIDE,
 	OP_MODULO,
-	TEST_OP_NOTZERO,
 	TEST_OP_CONTAINS,
 	TEST_OP_MATCHES,
 	TEST_OP_IN