rtlil: add Module* back-pointer to RTLIL::Memory

kernel/mem.cc

@@ -294,6 +294,7 @@ void Mem::emit() {
 				memid = NEW_ID;
 			mem = new RTLIL::Memory;
 			mem->name = memid;
+			mem->module = module;
 			module->memories[memid] = mem;
 		}
 		mem->width = width;

kernel/rtlil.cc

@@ -3611,6 +3611,7 @@ RTLIL::Memory *RTLIL::Module::addMemory(RTLIL::IdString name)
 {
 	RTLIL::Memory *mem = new RTLIL::Memory;
 	mem->name = std::move(name);
+	mem->module = this;
 	memories[mem->name] = mem;
 	return mem;
 }
@@ -3619,14 +3620,15 @@ RTLIL::Memory *RTLIL::Module::addMemory(RTLIL::IdString name, const RTLIL::Memor
 {
 	RTLIL::Memory *mem = new RTLIL::Memory;
 	mem->name = std::move(name);
+	mem->module = this;
 	mem->width = other->width;
 	mem->start_offset = other->start_offset;
 	mem->size = other->size;
 	mem->attributes = other->attributes;
 	{
-		// Memory has no module backpointer of its own — we can't know its
-		// source pool from `other` alone. Drop src in the rare clone-of-
-		// memory path; addMemory(name) is the common one and starts fresh.
+		// Clone path drops src for now — caller responsible for migrating
+		// src across the design boundary if needed. addMemory(name) is the
+		// common case.
 		(void)other;
 	}
 	memories[mem->name] = mem;

kernel/rtlil.h

@@ -2286,6 +2286,13 @@ struct RTLIL::Memory : public RTLIL::NamedObject
 
 	Memory();
 
+	// Back-pointer to the owning module — same role as Cell::module /
+	// Wire::module. Set by Module::addMemory / the frontends that
+	// construct Memory free-standing before attaching to a module.
+	// Lets Memory's src access (and the upcoming per-Design meta vector
+	// lookup) resolve uniformly via module->design.
+	RTLIL::Module *module = nullptr;
+
 	int width, start_offset, size;
 #ifdef YOSYS_ENABLE_PYTHON
 	~Memory();