verilog: support module scope identifiers in parametric modules

2 files changed, 37 insertions, 4 deletions

diff --git a/frontends/ast/simplify.cc b/frontends/ast/simplify.cc
index d68b13b2a..d9eae3a06 100644
--- a/frontends/ast/simplify.cc
+++ b/frontends/ast/simplify.cc
@@ -1691,11 +1691,15 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
 	if (type == AST_IDENTIFIER) {
 		if (current_scope.count(str) == 0) {
 			AstNode *current_scope_ast = (current_ast_mod == nullptr) ? current_ast : current_ast_mod;
-			const std::string& mod_scope = current_scope_ast->str;
-			if (str[0] == '\\' && str.substr(0, mod_scope.size()) == mod_scope) {
-				std::string new_str = "\\" + str.substr(mod_scope.size() + 1);
+			size_t pos = str.find('.', 1);
+			if (str[0] == '\\' && pos != std::string::npos) {
+				std::string new_str = "\\" + str.substr(pos + 1);
 				if (current_scope.count(new_str)) {
-					str = new_str;
+					std::string prefix = str.substr(0, pos);
+					auto it = current_scope_ast->attributes.find(ID::hdlname);
+					if ((it != current_scope_ast->attributes.end() && it->second->str == prefix)
+							|| prefix == current_scope_ast->str)
+						str = new_str;
 				}
 			}
 			for (auto node : current_scope_ast->children) {
diff --git a/tests/simple/module_scope.v b/tests/simple/module_scope.v
new file mode 100644
index 000000000..3e46b72ef
--- /dev/null
+++ b/tests/simple/module_scope.v
@@ -0,0 +1,29 @@
+`default_nettype none
+
+module Example(o1, o2);
+   parameter [31:0] v1 = 10;
+   parameter [31:0] v2 = 20;
+   output [31:0] o1, o2;
+   assign Example.o1 = Example.v1;
+   assign Example.o2 = Example.v2;
+endmodule
+
+module ExampleLong(o1, o2);
+   parameter [31:0] ThisIsAnExtremelyLongParameterNameToTriggerTheSHA1Checksum1 = 10;
+   parameter [31:0] ThisIsAnExtremelyLongParameterNameToTriggerTheSHA1Checksum2 = 20;
+   output [31:0] o1, o2;
+   assign ExampleLong.o1 = ExampleLong.ThisIsAnExtremelyLongParameterNameToTriggerTheSHA1Checksum1;
+   assign ExampleLong.o2 = ExampleLong.ThisIsAnExtremelyLongParameterNameToTriggerTheSHA1Checksum2;
+endmodule
+
+module top(
+   output [31:0] a1, a2, b1, b2, c1, c2,
+   output [31:0] d1, d2, e1, e2, f1, f2
+);
+   Example a(a1, a2);
+   Example #(1) b(b1, b2);
+   Example #(1, 2) c(c1, c2);
+   ExampleLong d(d1, d2);
+   ExampleLong #(1) e(e1, e2);
+   ExampleLong #(1, 2) f(f1, f2);
+endmodule