Fix duplicate type names generated in headers file

For example, there are many 'enum value_PR' and 'struct value' generated if
a class is instantiated as many instances.

typedef enum value_PR {
    value_PR_NOTHING,    /* No components present */
    .....
} value_PR;

typedef struct ProtocolIE_Field_6563P5 {
    ....
    struct value {
        value_PR present;
        union value_u {
        } choice;

        /* Context for parsing across buffer boundaries */
        asn_struct_ctx_t _asn_ctx;
    } value;

    /* Context for parsing across buffer boundaries */
    asn_struct_ctx_t _asn_ctx;
} ProtocolIE_Field_6563P5_t;

libasn1compiler/asn1c_C.c

@@ -1065,6 +1065,7 @@ asn1c_lang_C_OpenType(arg_t *arg, asn1c_ioc_table_and_objset_t *opt_ioc,
     open_type_choice->meta_type = AMT_TYPE;
     open_type_choice->expr_type = ASN_CONSTR_OPEN_TYPE;
     open_type_choice->_type_unique_index = arg->expr->_type_unique_index;
+    open_type_choice->parent_expr = arg->expr->parent_expr;
 
     for(size_t row = 0; row < opt_ioc->ioct->rows; row++) {
         struct asn1p_ioc_cell_s *cell =
@@ -1073,6 +1074,8 @@ asn1c_lang_C_OpenType(arg_t *arg, asn1c_ioc_table_and_objset_t *opt_ioc,
         if(!cell->value) 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);
     }
 
@@ -1285,11 +1288,14 @@ asn1c_lang_C_type_SIMPLE_TYPE(arg_t *arg) {
 			}
 		}
 
-
+		if(!(expr->_mark & TM_SKIPinUNION))
 			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));
+			}
 			if((expr->marker.flags & (EM_DEFAULT & ~EM_INDIRECT))
 					== (EM_DEFAULT & ~EM_INDIRECT))
 				OUT("\t/* DEFAULT %s */",
@@ -2659,7 +2665,7 @@ emit_member_type_selector(arg_t *arg, asn1p_expr_t *expr, asn1c_ioc_table_and_ob
 
     REDIR(OT_CODE);
     OUT("static asn_type_selector_result_t\n");
-    OUT("select_%s_type(const asn_TYPE_descriptor_t *parent_type, const void *parent_sptr) {\n", MKID_safe(expr));
+    OUT("select_%s_type(const asn_TYPE_descriptor_t *parent_type, const void *parent_sptr) {\n", c_name(arg).compound_name);
     INDENT(+1);
 
     OUT("asn_type_selector_result_t result = {0, 0};\n");
@@ -2717,7 +2723,7 @@ emit_member_type_selector(arg_t *arg, asn1p_expr_t *expr, asn1c_ioc_table_and_ob
     OUT("\n");
 
     REDIR(save_target);
-    OUT("select_%s_type", MKID_safe(expr));
+    OUT("select_%s_type", c_name(arg).compound_name);
 
     return 0;
 }

libasn1compiler/asn1c_naming.c

@@ -173,8 +173,11 @@ c_name_impl(arg_t *arg, asn1p_expr_t *expr, int avoid_keywords) {
     construct_base_name(&b_as_member, expr, 0, 1);
 
     static abuf tmp_compoundable_part_name;
+    static abuf compound_part_name;
     abuf_clear(&tmp_compoundable_part_name);
+    abuf_clear(&compound_part_name);
     construct_base_name(&tmp_compoundable_part_name, expr, compound_names, 0);
+    construct_base_name(&compound_part_name, expr, 1, 0);
 
     if(!expr->_anonymous_type) {
         if(arg->embed) {
@@ -204,6 +207,7 @@ c_name_impl(arg_t *arg, asn1p_expr_t *expr, int avoid_keywords) {
     names.presence_name = b_presence_name.buffer;
     names.members_enum = b_members_enum.buffer;
     names.members_name = b_members_name.buffer;
+    names.compound_name = compound_part_name.buffer;
 
     /* A _subset_ of names is checked against being globally unique */
     register_global_name(expr, names.base_name);

libasn1compiler/asn1c_naming.h

@@ -23,6 +23,7 @@ struct c_names {
     const char *presence_name; /* "foo_PR" */
     const char *members_enum;  /* "enum foo" */
     const char *members_name;  /* "e_foo" */
+    const char *compound_name; /* always contain "parent_foo" */
 };
 
 struct c_names c_name(arg_t *);

libasn1parser/asn1p_expr.c

@@ -30,6 +30,10 @@ asn1p_expr_set_source(asn1p_expr_t *expr, asn1p_module_t *module, int lineno) {
 
 int
 asn1p_expr_compare(const asn1p_expr_t *a, const asn1p_expr_t *b) {
+    if((a && !b) || (!a && b)) {
+        return -1;
+    }
+
     if(a->meta_type != b->meta_type || a->expr_type != b->expr_type) {
         return -1;
     }
@@ -185,6 +189,8 @@ asn1p_expr_clone_impl(asn1p_expr_t *expr, int skip_extensions, asn1p_expr_t *(*r
 	CLCOPY(tag);
 	CLCOPY(marker.flags);		/* OPTIONAL/DEFAULT */
 	CLCOPY(_mark);
+	CLCOPY(parent_expr);
+	CLCOPY(_type_unique_index);
 
 	clone->data = 0;	/* Do not clone this */
 	clone->data_free = 0;	/* Do not clone this */
@@ -303,6 +309,23 @@ asn1p_expr_add_many(asn1p_expr_t *to, asn1p_expr_t *from_what) {
 	TQ_CONCAT(&(to->members), &(from_what->members), next);
 }
 
+/*
+ * Lookup a child by its name.
+ */
+asn1p_expr_t *
+asn1p_lookup_child(asn1p_expr_t *tc, const char *name) {
+	asn1p_expr_t *child_tc;
+
+	TQ_FOR(child_tc, &(tc->members), next) {
+		if(child_tc->Identifier
+		&& strcmp(child_tc->Identifier, name) == 0) {
+			return child_tc;
+		}
+	}
+
+	errno = ESRCH;
+	return NULL;
+}
 
 /*
  * Destruct the types collection structure.

libasn1parser/asn1p_expr.h

@@ -251,7 +251,9 @@ typedef struct asn1p_expr_s {
 	  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_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. */
 	} _mark;
 
 	/*
@@ -280,6 +282,7 @@ asn1p_expr_t *asn1p_expr_clone_with_resolver(asn1p_expr_t *,
 	void *resolver_arg);
 void asn1p_expr_add(asn1p_expr_t *to, asn1p_expr_t *what);
 void asn1p_expr_add_many(asn1p_expr_t *to, asn1p_expr_t *from_what);
+asn1p_expr_t *asn1p_lookup_child(asn1p_expr_t *tc, const char *name);
 int asn1p_expr_compare(const asn1p_expr_t *, const asn1p_expr_t *);
 void asn1p_expr_free(asn1p_expr_t *expr);
 void asn1p_expr_set_source(asn1p_expr_t *, asn1p_module_t *, int lineno);