Add support for specific package imports

frontends/ast/simplify.cc

@@ -889,6 +889,52 @@ static void check_auto_nosync(AstNode *node)
 		check_auto_nosync(child.get());
 }
 
+class PackageImporter {
+	std::set<std::string> import_items;
+	bool is_wildcard;
+	const AstNode* node;
+public:
+	PackageImporter(const AstNode* n, const AstNode* child) : node(n) {
+		is_wildcard = child->children.empty();
+		// For specific imports, collect the list of items to import
+		if (!is_wildcard) {
+			for (auto& item : child->children) {
+				import_items.insert(item->str);
+			}
+		}
+	}
+
+	void import(std::map<std::string, AstNode*>& scope, AstNode* to_import) const {
+		// Check if this is a specific import and if this item should be imported
+		if (!is_wildcard && import_items.count(to_import->str) == 0)
+			return;
+
+		if (to_import->type == AST_PARAMETER || to_import->type == AST_LOCALPARAM ||
+			to_import->type == AST_TYPEDEF || to_import->type == AST_FUNCTION ||
+			to_import->type == AST_TASK || to_import->type == AST_ENUM) {
+			// For wildcard imports, check if item already exists (from specific import)
+			if (is_wildcard && scope.count(to_import->str) > 0)
+				return;
+			scope[to_import->str] = to_import;
+		}
+		if (to_import->type == AST_ENUM) {
+			for (auto& enode : to_import->children) {
+				log_assert(enode->type==AST_ENUM_ITEM);
+				// Check if this enum item should be imported
+				if (!is_wildcard && import_items.count(enode->str) == 0)
+					continue;
+				// For wildcard imports, check if item already exists (from specific import)
+				if (is_wildcard && scope.count(enode->str) > 0)
+					continue;
+				if (scope.count(enode->str) == 0)
+					scope[enode->str] = enode.get();
+				else
+					node->input_error("enum item %s already exists in current scope\n", enode->str);
+			}
+		}
+	}
+};
+
 // convert the AST into a simpler AST that has all parameters substituted by their
 // values, unrolled for-loops, expanded generate blocks, etc. when this function
 // is done with an AST it can be converted into RTLIL using genRTLIL().
@@ -1123,22 +1169,10 @@ bool AstNode::simplify(bool const_fold, int stage, int width_hint, bool sign_hin
 				}
 
 				if (package_node) {
-					// Import all names from the package into current scope
+					PackageImporter importer(this, child);
+					// Import names from the package into current scope
 					for (auto& pkg_child : package_node->children) {
-						if (pkg_child->type == AST_PARAMETER || pkg_child->type == AST_LOCALPARAM ||
-							pkg_child->type == AST_TYPEDEF || pkg_child->type == AST_FUNCTION ||
-							pkg_child->type == AST_TASK || pkg_child->type == AST_ENUM) {
-							current_scope[pkg_child->str] = pkg_child.get();
-						}
-						if (pkg_child->type == AST_ENUM) {
-							for (auto& enode : pkg_child->children) {
-								log_assert(enode->type==AST_ENUM_ITEM);
-								if (current_scope.count(enode->str) == 0)
-									current_scope[enode->str] = enode.get();
-								else
-									input_error("enum item %s already exists in current scope\n", enode->str);
-							}
-						}
+						importer.import(current_scope, pkg_child.get());
 					}
 					// Remove the import node since it's been processed
 					children.erase(children.begin() + i);

frontends/verilog/verilog_parser.y

@@ -829,11 +829,31 @@ package_body_stmt:
 	typedef_decl | localparam_decl | param_decl | task_func_decl;
 
 import_stmt:
-	TOK_IMPORT hierarchical_id TOK_PACKAGESEP TOK_ASTER TOK_SEMICOL {
-		// Create an import node to track package imports
+	TOK_IMPORT TOK_ID TOK_PACKAGESEP TOK_ASTER TOK_SEMICOL {
+		// Create an import node to track wildcard package imports
 		auto import_node = std::make_unique<AstNode>(@$, AST_IMPORT);
 		import_node->str = *$2;
 		extra->ast_stack.back()->children.push_back(std::move(import_node));
+	} |
+	TOK_IMPORT TOK_ID TOK_PACKAGESEP {
+		// Start a specific import: create and push the AST_IMPORT node
+		AstNode* import_node = extra->pushChild(std::make_unique<AstNode>(@$, AST_IMPORT));
+		import_node->str = *$2;
+	} import_item_list TOK_SEMICOL {
+		// Done collecting specific items, pop the AST_IMPORT node
+		extra->ast_stack.pop_back();
+	};
+
+import_item_list:
+	import_item |
+	import_item_list TOK_COMMA import_item ;
+
+import_item:
+	TOK_ID {
+		// Append this specific import name under the current AST_IMPORT
+		auto item_node = std::make_unique<AstNode>(@$, AST_NONE);
+		item_node->str = *$1;
+		extra->ast_stack.back()->children.push_back(std::move(item_node));
 	};
 
 interface:

tests/verilog/package_import_specific.sv

@@ -0,0 +1,14 @@
+package package_import_specific;
+
+  localparam integer
+    DATA_WIDTH = 8,
+    ADDR_WIDTH = 4;
+
+  localparam logic [2:0]
+    IDLE  = 3'b000,
+    START = 3'b001,
+    DATA  = 3'b010,
+    STOP  = 3'b100,
+    DONE  = 3'b101;
+
+endpackage

tests/verilog/package_import_specific.ys

@@ -0,0 +1,5 @@
+read_verilog -sv package_import_specific.sv
+read_verilog -sv package_import_specific_module.sv
+hierarchy -check
+proc
+opt -full

tests/verilog/package_import_specific_module.sv

@@ -0,0 +1,16 @@
+import package_import_specific::DATA_WIDTH;
+import package_import_specific::IDLE;
+
+module package_import_specific_module;
+  logic [DATA_WIDTH-1:0] data;
+  logic [3:0] addr;
+  logic [2:0] state;
+
+  always_comb begin
+    case (state)
+      IDLE: data = 8'h00;
+      default: data = 8'hFF;
+    endcase
+  end
+
+endmodule