Use a simplier method to solve duplicate type names generated

If one item's name already exists in this OPEN TYPE, simply do not
add it to expression open_type_choice.

It slightly modifies previous commit :
dcc822a0.

libasn1compiler/asn1c_C.c

@@ -1067,9 +1067,10 @@ asn1c_lang_C_OpenType(arg_t *arg, asn1c_ioc_table_and_objset_t *opt_ioc,
 
         if(!cell->value) continue;
 
+        if(asn1p_lookup_child(open_type_choice, cell->value->Identifier))
+            continue;
+
         asn1p_expr_t *m = asn1p_expr_clone(cell->value, 0);
-        if (asn1p_lookup_child(open_type_choice, m->Identifier))
-            m->_mark |= TM_SKIPinUNION;
         asn1p_expr_add(open_type_choice, m);
     }
 
@@ -1282,14 +1283,11 @@ asn1c_lang_C_type_SIMPLE_TYPE(arg_t *arg) {
 			}
 		}
 
-		if(!(expr->_mark & TM_SKIPinUNION))
-			OUT("%s", asn1c_type_name(arg, arg->expr, tnfmt));
+		OUT("%s", asn1c_type_name(arg, arg->expr, tnfmt));
 
 		if(!expr->_anonymous_type) {
-			if(!(expr->_mark & TM_SKIPinUNION)) {
-				OUT("%s", (expr->marker.flags&EM_INDIRECT)?"\t*":"\t ");
-				OUT("%s", MKID_safe(expr));
-			}
+			OUT("%s", (expr->marker.flags&EM_INDIRECT)?"\t*":"\t ");
+			OUT("%s", MKID_safe(expr));
 			if((expr->marker.flags & (EM_DEFAULT & ~EM_INDIRECT))
 					== (EM_DEFAULT & ~EM_INDIRECT))
 				OUT("\t/* DEFAULT %s */",

libasn1parser/asn1p_expr.h

@@ -250,10 +250,8 @@ typedef struct asn1p_expr_s {
 	  TM_RECURSION	= (1<<0), /* Used to break recursion */
 	  TM_BROKEN	= (1<<1), /* A warning was already issued */
 	  TM_PERFROMCT	= (1<<2), /* PER FROM() constraint tables emitted */
-	  TM_NAMECLASH	= (1<<3),  /* Name clash found, need to add module name to resolve */
-	  TM_NAMEGIVEN  = (1<<4),  /* The expression has already yielded a name */
-	  TM_SKIPinUNION  = (1<<5) /* Do not include this identifier in union again due to name duplication,
-                                      especially for OPENTYPE. */
+	  TM_NAMECLASH	= (1<<3), /* Name clash found, need to add module name to resolve */
+	  TM_NAMEGIVEN  = (1<<4)  /* The expression has already yielded a name */
 	} _mark;
 
 	/*

tests/tests-asn1c-compiler/156-union-ios-OK.asn1.-Pgen-PER

@@ -78,7 +78,6 @@ typedef enum value_PR {
 	value_PR_NOTHING,	/* No components present */
 	value_PR_INTEGER,
 	value_PR_BOOLEAN,
-	value_PR_BOOLEAN,
 	value_PR_OCTET_STRING
 } value_PR;
 
@@ -91,7 +90,6 @@ typedef struct SpecializedContent_42P0 {
 		union SpecializedContent_42P0__value_u {
 			long	 INTEGER;
 			BOOLEAN_t	 BOOLEAN;
-		;
 			OCTET_STRING_t	 OCTET_STRING;
 		} choice;
 		
@@ -227,15 +225,6 @@ static asn_TYPE_member_t asn_MBR_value_3[] = {
 		0, 0, /* No default value */
 		.name = "BOOLEAN"
 		},
-	{ ATF_NOFLAGS, 0, offsetof(struct value, choice.BOOLEAN),
-		.tag = (ASN_TAG_CLASS_UNIVERSAL | (1 << 2)),
-		.tag_mode = 0,
-		.type = &asn_DEF_BOOLEAN,
-		.type_selector = 0,
-		{ .oer_constraints = 0, .per_constraints = 0, .general_constraints = 0 },
-		0, 0, /* No default value */
-		.name = "BOOLEAN"
-		},
 	{ ATF_NOFLAGS, 0, offsetof(struct value, choice.OCTET_STRING),
 		.tag = (ASN_TAG_CLASS_UNIVERSAL | (4 << 2)),
 		.tag_mode = 0,
@@ -246,13 +235,12 @@ static asn_TYPE_member_t asn_MBR_value_3[] = {
 		.name = "OCTET STRING"
 		},
 };
-static const unsigned asn_MAP_value_to_canonical_3[] = { 1, 2, 0, 3 };
-static const unsigned asn_MAP_value_from_canonical_3[] = { 2, 0, 1, 3 };
+static const unsigned asn_MAP_value_to_canonical_3[] = { 1, 0, 2 };
+static const unsigned asn_MAP_value_from_canonical_3[] = { 1, 0, 2 };
 static const asn_TYPE_tag2member_t asn_MAP_value_tag2el_3[] = {
-    { (ASN_TAG_CLASS_UNIVERSAL | (1 << 2)), 1, 0, 1 }, /* BOOLEAN */
-    { (ASN_TAG_CLASS_UNIVERSAL | (1 << 2)), 2, -1, 0 }, /* BOOLEAN */
+    { (ASN_TAG_CLASS_UNIVERSAL | (1 << 2)), 1, 0, 0 }, /* BOOLEAN */
     { (ASN_TAG_CLASS_UNIVERSAL | (2 << 2)), 0, 0, 0 }, /* INTEGER */
-    { (ASN_TAG_CLASS_UNIVERSAL | (4 << 2)), 3, 0, 0 } /* OCTET STRING */
+    { (ASN_TAG_CLASS_UNIVERSAL | (4 << 2)), 2, 0, 0 } /* OCTET STRING */
 };
 static asn_CHOICE_specifics_t asn_SPC_value_specs_3 = {
 	sizeof(struct value),
@@ -260,7 +248,7 @@ static asn_CHOICE_specifics_t asn_SPC_value_specs_3 = {
 	offsetof(struct value, present),
 	sizeof(((struct value *)0)->present),
 	.tag2el = asn_MAP_value_tag2el_3,
-	.tag2el_count = 4,	/* Count of tags in the map */
+	.tag2el_count = 3,	/* Count of tags in the map */
 	.to_canonical_order = asn_MAP_value_to_canonical_3,
 	.from_canonical_order = asn_MAP_value_from_canonical_3,
 	.first_extension = -1	/* Extensions start */
@@ -276,7 +264,7 @@ asn_TYPE_descriptor_t asn_DEF_value_3 = {
 	0,	/* No tags (count) */
 	{ 0, 0, OPEN_TYPE_constraint },
 	asn_MBR_value_3,
-	4,	/* Elements count */
+	3,	/* Elements count */
 	&asn_SPC_value_specs_3	/* Additional specs */
 };