Added support for continue and break statements

Author: johanjino

include/ast.hpp

@@ -11,6 +11,9 @@
 #include "ast/Function/ast_sizeof.hpp"
 
 #include "ast/Keyword/ast_return.hpp"
+#include "ast/Keyword/ast_break.hpp"
+#include "ast/Keyword/ast_continue.hpp"
+
 #include "ast/Types/ast_types.hpp"
 #include "ast/Arrays/ast_arrays.hpp"
 

include/ast/Blocks/ast_forloop.hpp

@@ -46,7 +46,9 @@ class forloop : public Node {
 
             //create labels
             std::string start_loop = helper.createLabel("start_for");
+            std::string update_loop = helper.createLabel("update_con");
             std::string end_loop = helper.createLabel("end_for");
+            helper.new_loop(start_loop, end_loop, update_loop);
 
             //initialise condition
             init_cont->riscv_asm(dst,helper,destReg,bindings);
@@ -61,15 +63,17 @@ class forloop : public Node {
             if (for_block!=NULL){
                 for_block->riscv_asm(dst,helper,destReg,bindings);
             }
+            //update conditions
+            dst<<update_loop<<":"<<std::endl;
             update_cont->riscv_asm(dst,helper,destReg,bindings);
             dst<<"beq zero, zero, "<<start_loop<<std::endl;
 
             //end loop
             dst<<end_loop<<":"<<std::endl;
+            helper.exit_loop();
 
             //clear registers
             if (init_cont->getType() != "NULL"){               // if control was intialised within loop construct -> need to earse it
-                dst<<"addi "<<bindings[init_cont->getId()][0]<<", zero, 0"<<std::endl;
                 bindings.erase(init_cont->getId());
             }
             dst<<"addi "<<condition_reg<<", zero, 0"<<std::endl;

include/ast/Blocks/ast_whileloop.hpp

@@ -44,6 +44,7 @@ class whileloop : public Node {
             //create labels
             std::string start_loop = helper.createLabel("start_while");
             std::string end_loop = helper.createLabel("end_while");
+            helper.new_loop(start_loop, end_loop);
 
             //evalute conditon
             std::string condition_reg = helper.allocateReg("None");  //this is not ideal, prevents unwanted float regs being used
@@ -59,6 +60,8 @@ class whileloop : public Node {
 
             //end loop
             dst<<end_loop<<":"<<std::endl;
+            helper.exit_loop();
+            
 
             //clear registers
             dst<<"addi "<<condition_reg<<", zero, 0"<<std::endl;

include/ast/Keyword/ast_break.hpp

@@ -0,0 +1,27 @@
+#ifndef ast_break_hpp
+#define ast_break_hpp
+
+#include <string>
+#include <iostream>
+
+#include "../ast_node.hpp"
+
+class Break : public Node {
+    public:
+        Break()
+        {}
+        virtual void print(std::ostream &dst, int span) const override{
+            dst<<std::setw(span*4)<<"break ";
+            dst<<std::endl;
+        }
+
+         virtual void riscv_asm(std::ostream &dst,
+            Helper &helper,
+            std::string destReg,
+            std::map<std::string, std::vector<std::string>> &bindings,
+            std::string datatype = "None")const override{
+
+                dst<<"beq zero, zero, "<<helper.get_loop_labels("End")<<std::endl;
+            }
+};
+#endif

include/ast/Keyword/ast_continue.hpp

@@ -0,0 +1,35 @@
+#ifndef ast_continue_hpp
+#define ast_continue_hpp
+
+#include <string>
+#include <iostream>
+
+#include "../ast_node.hpp"
+
+
+
+class Continue : public Node {
+    public:
+        Continue()
+        {}
+        virtual void print(std::ostream &dst, int span) const override{
+            dst<<std::setw(span*4)<<"continue ";
+            dst<<std::endl;
+        }
+
+        virtual void riscv_asm(std::ostream &dst,
+            Helper &helper,
+            std::string destReg,
+            std::map<std::string, std::vector<std::string>> &bindings,
+            std::string datatype = "None")const override{
+                std::string label = helper.get_loop_labels("Update");
+                if (label == "None"){
+                    //in while loop then -> use "Start" instead
+                    label = helper.get_loop_labels("Start");
+                }
+                dst<<"beq zero, zero, "<<label<<std::endl;
+            }
+};
+
+
+#endif

include/ast/Keyword/ast_return.hpp

@@ -33,24 +33,6 @@ class Return : public Node {
         }
 };
 
-class Continue : public Node {
-    public:
-        Continue()
-        {}
-        virtual void print(std::ostream &dst, int span) const override{
-            dst<<std::setw(span*4)<<"continue ";
-            dst<<std::endl;
-        }
-};
 
-class Break : public Node {
-    public:
-        Break()
-        {}
-        virtual void print(std::ostream &dst, int span) const override{
-            dst<<std::setw(span*4)<<"break ";
-            dst<<std::endl;
-        }
-};
 
 #endif

include/ast/ast_helper.hpp

@@ -60,7 +60,50 @@ class Helper {
 
 
 
-
+        // loop end and start
+        std::string current_loop_end;
+        std::string current_loop_update;
+        std::string current_loop_start;
+        std::vector<std::string> loop_end;
+        std::vector<std::string> loop_update;
+        std::vector<std::string> loop_start;
+
+        void new_loop(std::string new_loop_start, std::string new_loop_end, std::string new_loop_update = "None"){
+            loop_start.push_back(new_loop_start);
+            loop_update.push_back(new_loop_update);
+            loop_end.push_back(new_loop_end);
+            current_loop_start = new_loop_start;
+            current_loop_update = new_loop_update;
+            current_loop_end = new_loop_end;
+        }
+        void exit_loop(){
+            if (!loop_start.empty()){
+                current_loop_start = loop_start.back();
+                current_loop_update = loop_update.back();
+                current_loop_end = loop_end.back();
+                loop_start.pop_back();
+                loop_update.pop_back();
+                loop_end.pop_back();
+            }
+            else{
+                std::cerr << "Tried to break or continue in a scope of no loops" << std::endl;
+                exit(1);
+            }
+        }
+        std::string get_loop_labels(std::string where){
+            if (where == "Start"){
+                return current_loop_start;
+            }
+            else if (where == "End"){
+                return current_loop_end;
+            }
+            else if (where == "Update"){
+                return current_loop_update;
+            }
+            else{
+                return "invalid location to jump";
+            }
+        }
 
 
         //Creates Labels for function jumps