libsepol/cil: Move check for the shadowing of macro parameters

In cil_gen_node(), after the declaration is added to the symbol
table, if the parent is a macro, then a check is made to ensure
the declaration does not shadow any of the macro's parameters.
This check also needs to be done when copying the AST.

Move the check for the shadowing of macro parameters to its own
function, cil_verify_decl_does_not_shadow_macro_parameter(), and
refactor cil_gen_node() and __cil_copy_node_helper() to use the
new function.

Signed-off-by: James Carter <jwcart2@gmail.com>

libsepol/cil/src/cil_build_ast.c

@@ -161,19 +161,9 @@ int cil_gen_node(struct cil_db *db, struct cil_tree_node *ast_node, struct cil_s
 	}
 
 	if (ast_node->parent->flavor == CIL_MACRO) {
-		struct cil_list_item *item;
-		struct cil_list *param_list = ((struct cil_macro*)ast_node->parent->data)->params;
-		if (param_list != NULL) {
-			cil_list_for_each(item, param_list) {
-				struct cil_param *param = item->data;
-				if (param->flavor == ast_node->flavor) {
-					if (param->str == key) {
-						cil_log(CIL_ERR, "%s %s shadows a macro parameter in macro declaration\n", cil_node_to_string(ast_node), key);
-						rc = SEPOL_ERR;
-						goto exit;
-					}
-				}
-			}
+		rc = cil_verify_decl_does_not_shadow_macro_parameter(ast_node->parent->data, ast_node, key);
+		if (rc != SEPOL_OK) {
+			goto exit;
 		}
 	}
 

libsepol/cil/src/cil_copy_ast.c

@@ -40,6 +40,7 @@
 #include "cil_copy_ast.h"
 #include "cil_build_ast.h"
 #include "cil_strpool.h"
+#include "cil_verify.h"
 
 struct cil_args_copy {
 	struct cil_tree_node *dest;
@@ -1716,7 +1717,6 @@ int __cil_copy_node_helper(struct cil_tree_node *orig, __attribute__((unused)) u
 	struct cil_db *db = NULL;
 	struct cil_args_copy *args = NULL;
 	struct cil_tree_node *namespace = NULL;
-	struct cil_param *param = NULL;
 	enum cil_sym_index sym_index = CIL_SYM_UNKNOWN;
 	symtab_t *symtab = NULL;
 	void *data = NULL;
@@ -2043,21 +2043,9 @@ int __cil_copy_node_helper(struct cil_tree_node *orig, __attribute__((unused)) u
 			}
 
 			if (namespace->flavor == CIL_MACRO) {
-				struct cil_macro *macro = namespace->data;
-				struct cil_list *param_list = macro->params;
-				if (param_list != NULL) {
-					struct cil_list_item *item;
-					cil_list_for_each(item, param_list) {
-						param = item->data;
-						if (param->flavor == new->flavor) {
-							if (param->str == ((struct cil_symtab_datum*)new->data)->name) {
-								cil_tree_log(orig, CIL_ERR, "%s %s shadows a macro parameter", cil_node_to_string(new), ((struct cil_symtab_datum*)orig->data)->name);
-								cil_tree_log(namespace, CIL_ERR, "Note: macro declaration");
-								rc = SEPOL_ERR;
-								goto exit;
-							}
-						}
-					}
+				rc = cil_verify_decl_does_not_shadow_macro_parameter(namespace->data, orig, DATUM(orig->data)->name);
+				if (rc != SEPOL_OK) {
+					goto exit;
 				}
 			}
 		}

libsepol/cil/src/cil_verify.c

@@ -412,6 +412,24 @@ int cil_verify_conditional_blocks(struct cil_tree_node *current)
 	return SEPOL_OK;
 }
 
+int cil_verify_decl_does_not_shadow_macro_parameter(struct cil_macro *macro, struct cil_tree_node *node, const char *name)
+{
+	struct cil_list_item *item;
+	struct cil_list *param_list = macro->params;
+	if (param_list != NULL) {
+		cil_list_for_each(item, param_list) {
+			struct cil_param *param = item->data;
+			if (param->flavor == node->flavor) {
+				if (param->str == name) {
+					cil_log(CIL_ERR, "%s %s shadows a macro parameter in macro declaration\n", cil_node_to_string(node), name);
+					return SEPOL_ERR;
+				}
+			}
+		}
+	}
+	return SEPOL_OK;
+}
+
 int cil_verify_no_self_reference(struct cil_symtab_datum *datum, struct cil_list *datum_list)
 {
 	struct cil_list_item *i;

libsepol/cil/src/cil_verify.h

@@ -62,6 +62,7 @@ int cil_verify_expr_syntax(struct cil_tree_node *current, enum cil_flavor op, en
 int cil_verify_constraint_leaf_expr_syntax(enum cil_flavor l_flavor, enum cil_flavor r_flavor, enum cil_flavor op, enum cil_flavor expr_flavor);
 int cil_verify_constraint_expr_syntax(struct cil_tree_node *current, enum cil_flavor op);
 int cil_verify_conditional_blocks(struct cil_tree_node *current);
+int cil_verify_decl_does_not_shadow_macro_parameter(struct cil_macro *macro, struct cil_tree_node *node, const char *name);
 int cil_verify_no_self_reference(struct cil_symtab_datum *datum, struct cil_list *datum_list);
 int __cil_verify_ranges(struct cil_list *list);
 int __cil_verify_ordered_node_helper(struct cil_tree_node *node, uint32_t *finished, void *extra_args);