Split out logic for reprocessing an AstModule

This will enable other features to use same core logic for replacing an
existing AstModule with a newly elaborated version.

2 files changed, 57 insertions, 24 deletions

diff --git a/frontends/ast/ast.cc b/frontends/ast/ast.cc
index 4fbc238b0..fe1f9e861 100644
--- a/frontends/ast/ast.cc
+++ b/frontends/ast/ast.cc
@@ -983,8 +983,7 @@ static bool param_has_no_default(const AstNode *param) {
 		(children.size() == 1 && children[0]->type == AST_RANGE);
 }
 
-// create and add a new AstModule from an AST_MODULE AST node
-static void process_module(RTLIL::Design *design, AstNode *ast, bool defer, AstNode *original_ast = NULL, bool quiet = false)
+static RTLIL::Module *process_module(RTLIL::Design *design, AstNode *ast, bool defer, AstNode *original_ast = NULL, bool quiet = false)
 {
 	log_assert(current_scope.empty());
 	log_assert(ast->type == AST_MODULE || ast->type == AST_INTERFACE);
@@ -1197,6 +1196,42 @@ static void process_module(RTLIL::Design *design, AstNode *ast, bool defer, AstN
 	}
 
 	design->add(current_module);
+	return current_module;
+}
+
+RTLIL::Module *
+AST_INTERNAL::process_and_replace_module(RTLIL::Design *design,
+                                         RTLIL::Module *old_module,
+                                         AstNode *new_ast,
+                                         AstNode *original_ast)
+{
+	// The old module will be deleted. Rename and mark for deletion, using
+	// a static counter to make sure we get a unique name.
+	static unsigned counter;
+	std::ostringstream new_name;
+	new_name << old_module->name.str()
+		 << "_before_process_and_replace_module_"
+		 << counter;
+	++counter;
+
+	design->rename(old_module, new_name.str());
+	old_module->set_bool_attribute(ID::to_delete);
+
+	// Check if the module was the top module. If it was, we need to remove
+	// the top attribute and put it on the new module.
+	bool is_top = false;
+	if (old_module->get_bool_attribute(ID::initial_top)) {
+		old_module->attributes.erase(ID::initial_top);
+		is_top = true;
+	}
+
+	// Generate RTLIL from AST for the new module and add to the design:
+	RTLIL::Module* new_module = process_module(design, new_ast, false, original_ast);
+
+	if (is_top)
+		new_module->set_bool_attribute(ID::top);
+
+	return new_module;
 }
 
 // renames identifiers in tasks and functions within a package
@@ -1412,11 +1447,10 @@ void AST::explode_interface_port(AstNode *module_ast, RTLIL::Module * intfmodule
 
 // When an interface instance is found in a module, the whole RTLIL for the module will be rederived again
 // from AST. The interface members are copied into the AST module with the prefix of the interface.
-void AstModule::reprocess_module(RTLIL::Design *design, const dict<RTLIL::IdString, RTLIL::Module*> &local_interfaces)
+void AstModule::expand_interfaces(RTLIL::Design *design, const dict<RTLIL::IdString, RTLIL::Module*> &local_interfaces)
 {
 	loadconfig();
 
-	bool is_top = false;
 	AstNode *new_ast = ast->clone();
 	for (auto &intf : local_interfaces) {
 		std::string intfname = intf.first.str();
@@ -1473,28 +1507,15 @@ void AstModule::reprocess_module(RTLIL::Design *design, const dict<RTLIL::IdStri
 		}
 	}
 
-	// The old module will be deleted. Rename and mark for deletion:
-	std::string original_name = this->name.str();
-	std::string changed_name = original_name + "_before_replacing_local_interfaces";
-	design->rename(this, changed_name);
-	this->set_bool_attribute(ID::to_delete);
+	// Generate RTLIL from AST for the new module and add to the design,
+	// renaming this module to move it out of the way.
+	RTLIL::Module* new_module =
+		process_and_replace_module(design, this, new_ast, ast_before_replacing_interface_ports);
 
-	// Check if the module was the top module. If it was, we need to remove the top attribute and put it on the
-	// new module.
-	if (this->get_bool_attribute(ID::initial_top)) {
-		this->attributes.erase(ID::initial_top);
-		is_top = true;
-	}
-
-	// Generate RTLIL from AST for the new module and add to the design:
-	process_module(design, new_ast, false, ast_before_replacing_interface_ports);
-	delete(new_ast);
-	RTLIL::Module* mod = design->module(original_name);
-	if (is_top)
-		mod->set_bool_attribute(ID::top);
+	delete new_ast;
 
 	// Set the attribute "interfaces_replaced_in_module" so that it does not happen again.
-	mod->set_bool_attribute(ID::interfaces_replaced_in_module);
+	new_module->set_bool_attribute(ID::interfaces_replaced_in_module);
 }
 
 // create a new parametric module (when needed) and return the name of the generated module - WITH support for interfaces
diff --git a/frontends/ast/ast.h b/frontends/ast/ast.h
index 63104bca4..66bbdd7b4 100644
--- a/frontends/ast/ast.h
+++ b/frontends/ast/ast.h
@@ -348,7 +348,7 @@ namespace AST
 		RTLIL::IdString derive(RTLIL::Design *design, const dict<RTLIL::IdString, RTLIL::Const> &parameters, bool mayfail) override;
 		RTLIL::IdString derive(RTLIL::Design *design, const dict<RTLIL::IdString, RTLIL::Const> &parameters, const dict<RTLIL::IdString, RTLIL::Module*> &interfaces, const dict<RTLIL::IdString, RTLIL::IdString> &modports, bool mayfail) override;
 		std::string derive_common(RTLIL::Design *design, const dict<RTLIL::IdString, RTLIL::Const> &parameters, AstNode **new_ast_out, bool quiet = false);
-		void reprocess_module(RTLIL::Design *design, const dict<RTLIL::IdString, RTLIL::Module *> &local_interfaces) override;
+		void expand_interfaces(RTLIL::Design *design, const dict<RTLIL::IdString, RTLIL::Module *> &local_interfaces) override;
 		RTLIL::Module *clone() const override;
 		void loadconfig() const;
 	};
@@ -395,6 +395,18 @@ namespace AST_INTERNAL
 	extern dict<std::string, pool<int>> current_memwr_visible;
 	struct LookaheadRewriter;
 	struct ProcessGenerator;
+
+	// Create and add a new AstModule from new_ast, then use it to replace
+	// old_module in design, renaming old_module to move it out of the way.
+	// Return the new module.
+	//
+	// If original_ast is not null, it will be used as the AST node for the
+	// new module. Otherwise, new_ast will be used.
+	RTLIL::Module *
+	process_and_replace_module(RTLIL::Design *design,
+	                           RTLIL::Module *old_module,
+	                           AST::AstNode *new_ast,
+	                           AST::AstNode *original_ast = nullptr);
 }
 
 YOSYS_NAMESPACE_END