kernel: add design -delete option

CHANGELOG

@@ -64,6 +64,7 @@ Yosys 0.9 .. Yosys 0.9-dev
     - Added "opt_lut_ins" pass
     - Added "logger" pass
     - Removed "dffsr2dff" (use opt_rmdff instead)
+    - Added "design -delete"
 
 Yosys 0.8 .. Yosys 0.9
 ----------------------

passes/cmds/design.cc

@@ -99,6 +99,11 @@ struct DesignPass : public Pass {
 		log("The Verilog front-end remembers defined macros and top-level declarations\n");
 		log("between calls to 'read_verilog'. This command resets this memory.\n");
 		log("\n");
+		log("    design -delete <name>\n");
+		log("\n");
+		log("Delete the design previously saved under the given name.\n");
+		log("\n");
+
 	}
 	void execute(std::vector<std::string> args, RTLIL::Design *design) YS_OVERRIDE
 	{
@@ -110,7 +115,7 @@ struct DesignPass : public Pass {
 		bool pop_mode = false;
 		bool import_mode = false;
 		RTLIL::Design *copy_from_design = NULL, *copy_to_design = NULL;
-		std::string save_name, load_name, as_name;
+		std::string save_name, load_name, as_name, delete_name;
 		std::vector<RTLIL::Module*> copy_src_modules;
 
 		size_t argidx;
@@ -190,6 +195,13 @@ struct DesignPass : public Pass {
 				as_name = args[++argidx];
 				continue;
 			}
+			if (!got_mode && args[argidx] == "-delete" && argidx+1 < args.size()) {
+				got_mode = true;
+				delete_name = args[++argidx];
+				if (saved_designs.count(delete_name) == 0)
+					log_cmd_error("No saved design '%s' found!\n", delete_name.c_str());
+				continue;
+			}
 			break;
 		}
 
@@ -379,6 +391,14 @@ struct DesignPass : public Pass {
 				pushed_designs.pop_back();
 			}
 		}
+
+		if (!delete_name.empty())
+		{
+			auto it = saved_designs.find(delete_name);
+			log_assert(it != saved_designs.end());
+			delete it->second;
+			saved_designs.erase(it);
+		}
 	}
 } DesignPass;