Implement while loops

gcc/elna-diagnostic.cc

@@ -1,26 +1,32 @@
 #include "elna/gcc/elna-diagnostic.h"
 
-location_t elna_gcc_location(const elna::source::position *position)
+namespace elna
 {
-    linemap_line_start(line_table, position->line, 0);
+namespace gcc
-
-    return linemap_position_for_column(line_table, position->column);
-}
-
-const char *elna_gcc_print_type(tree type)
 {
-    gcc_assert(TYPE_P(type));
+    location_t get_location(const elna::source::position *position)
+    {
+        linemap_line_start(line_table, position->line, 0);
 
-    if (type == integer_type_node)
+        return linemap_position_for_column(line_table, position->column);
-    {
-        return "Int";
     }
-    else if (type == boolean_type_node)
+
+    const char *print_type(tree type)
     {
-        return "Boolean";
+        gcc_assert(TYPE_P(type));
-    }
+
-    else
+        if (type == integer_type_node)
-    {
+        {
-        return "<<unknown-type>>";
+            return "Int";
+        }
+        else if (type == boolean_type_node)
+        {
+            return "Boolean";
+        }
+        else
+        {
+            return "<<unknown-type>>";
+        }
     }
 }
+}

gcc/elna-generic.cc

@@ -13,15 +13,40 @@ namespace gcc
 {
     void generic_visitor::visit(source::call_statement *statement)
     {
-        empty_visitor::visit(statement);
+        if (statement->name() != "writei")
+        {
+            error_at(get_location(&statement->position()),
+                    "procedure '%s' not declared",
+                    statement->name().c_str());
+            return;
+        }
+        if (statement->arguments().size() != 1)
+        {
+            error_at(get_location(&statement->position()),
+                    "procedure '%s' expects 1 argument, %i given",
+                    statement->name().c_str(), statement->arguments().size());
+            return;
+        }
+        auto& argument = statement->arguments().at(0);
+        argument->accept(this);
+        auto argument_type = TREE_TYPE(this->current_expression);
+        auto argument_tree = this->current_expression;
+        this->current_expression = NULL_TREE;
 
-        const char *format_integer = "%d\n";
+        if (argument_type != integer_type_node)
+        {
+            error_at(get_location(&argument->position()),
+                    "invalid argument of type %s for procedure %s",
+                    print_type(argument_type), statement->name().c_str());
+            return;
+        }
+        constexpr const char *format_integer = "%d\n";
         tree args[] = {
             build_string_literal(strlen(format_integer) + 1, format_integer),
-            this->current_expression
+            argument_tree
         };
         tree fndecl_type_param[] = {
-            build_pointer_type (build_qualified_type(char_type_node, TYPE_QUAL_CONST)) /* const char* */
+            build_pointer_type(build_qualified_type(char_type_node, TYPE_QUAL_CONST)) /* const char* */
         };
         tree fndecl_type = build_varargs_function_type_array(integer_type_node, 1, fndecl_type_param);
 
@@ -39,12 +64,12 @@ namespace gcc
     {
         tree main_fndecl_type_param[] = {
             integer_type_node,
-            build_pointer_type(build_pointer_type (char_type_node))
+            build_pointer_type(build_pointer_type(char_type_node))
         };
         tree main_fndecl_type = build_function_type_array(integer_type_node, 2, main_fndecl_type_param);
-        tree main_fndecl = build_fn_decl("main", main_fndecl_type);
+        this->main_fndecl = build_fn_decl("main", main_fndecl_type);
         tree resdecl = build_decl(UNKNOWN_LOCATION, RESULT_DECL, NULL_TREE, integer_type_node);
-        DECL_RESULT(main_fndecl) = resdecl;
+        DECL_RESULT(this->main_fndecl) = resdecl;
         tree set_result = build2(INIT_EXPR, void_type_node, DECL_RESULT(main_fndecl),
                 build_int_cst_type(integer_type_node, 0));
         tree return_stmt = build1(RETURN_EXPR, void_type_node, set_result);
@@ -58,16 +83,16 @@ namespace gcc
         tree new_block = build_block(NULL_TREE, NULL_TREE, NULL_TREE, NULL_TREE);
         tree bind_expr = build3(BIND_EXPR, void_type_node, NULL_TREE,  this->current_statements, new_block);
        
-        BLOCK_SUPERCONTEXT(new_block) = main_fndecl;
+        BLOCK_SUPERCONTEXT(new_block) = this->main_fndecl;
-        DECL_INITIAL(main_fndecl) = new_block;
+        DECL_INITIAL(this->main_fndecl) = new_block;
-        DECL_SAVED_TREE(main_fndecl) = bind_expr;
+        DECL_SAVED_TREE(this->main_fndecl) = bind_expr;
        
-        DECL_EXTERNAL(main_fndecl) = 0;
+        DECL_EXTERNAL(this->main_fndecl) = 0;
-        DECL_PRESERVE_P(main_fndecl) = 1;
+        DECL_PRESERVE_P(this->main_fndecl) = 1;
        
-        gimplify_function_tree(main_fndecl);
+        gimplify_function_tree(this->main_fndecl);
        
-        cgraph_node::finalize_function(main_fndecl, true);
+        cgraph_node::finalize_function(this->main_fndecl, true);
     }
 
     void generic_visitor::visit(source::integer_literal *literal)
@@ -84,11 +109,14 @@ namespace gcc
     {
         expression->lhs().accept(this);
         auto left = this->current_expression;
+        auto left_type = TREE_TYPE(left);
 
         expression->rhs().accept(this);
         auto right = this->current_expression;
+        auto right_type = TREE_TYPE(right);
 
-        tree_code operator_code{};
+        auto expression_location = get_location(&expression->position());
+        tree_code operator_code = ERROR_MARK;
 
         switch (expression->operation())
         {
@@ -104,23 +132,63 @@ namespace gcc
             case source::binary_operator::multiplication:
                 operator_code = MULT_EXPR;
                 break;
-            default:
-                gcc_unreachable();
         }
-
+        if (operator_code != ERROR_MARK) // An arithmetic operation.
-        this->current_expression = build2(operator_code, integer_type_node, left, right);
+        {
+            if (left_type != integer_type_node || right_type != integer_type_node)
+            {
+                error_at(expression_location,
+                        "invalid operands of type %s and %s for operator %s",
+                        print_type(left_type), print_type(right_type),
+                        elna::source::print_binary_operator(expression->operation()));
+                this->current_expression = error_mark_node;
+                return;
+            }
+        }
+        switch (expression->operation())
+        {
+            case source::binary_operator::equals:
+                operator_code = EQ_EXPR;
+                break;
+            case source::binary_operator::not_equals:
+                operator_code = NE_EXPR;
+                break;
+            case source::binary_operator::less:
+                operator_code = LT_EXPR;
+                break;
+            case source::binary_operator::greater:
+                operator_code = GT_EXPR;
+                break;
+            case source::binary_operator::less_equal:
+                operator_code = LE_EXPR;
+                break;
+            case source::binary_operator::greater_equal:
+                operator_code = GE_EXPR;
+                break;
+        }
+        if (left_type != right_type)
+        {
+            error_at(expression_location,
+                    "invalid operands of type %s and %s for operator %s",
+                    print_type(left_type), print_type(right_type),
+                    elna::source::print_binary_operator(expression->operation()));
+            this->current_expression = error_mark_node;
+            return;
+        }
+        this->current_expression = build2_loc(expression_location,
+                operator_code, integer_type_node, left, right);
     }
 
     void generic_visitor::visit(source::declaration *declaration)
     {
         if (declaration->type().base() != "Int" && declaration->type().base() != "Bool")
         {
-            error_at(elna_gcc_location(&declaration->type().position()),
+            error_at(get_location(&declaration->type().position()),
                     "type '%s' not declared",
                     declaration->type().base().c_str());
             return;
         }
-        auto declaration_location = elna_gcc_location(&declaration->position());
+        auto declaration_location = get_location(&declaration->position());
         tree declaration_tree = build_decl(declaration_location, VAR_DECL,
                 get_identifier(declaration->identifier().c_str()), integer_type_node);
         auto result = this->symbol_map.insert({ declaration->identifier(), declaration_tree });
@@ -145,7 +213,7 @@ namespace gcc
 
         if (symbol == this->symbol_map.end())
         {
-            error_at(elna_gcc_location(&expression->position()),
+            error_at(get_location(&expression->position()),
                     "variable '%s' not declared in the current scope",
                     expression->name().c_str());
             this->current_expression = error_mark_node;
@@ -157,7 +225,7 @@ namespace gcc
     void generic_visitor::visit(source::assign_statement *statement)
     {
         auto lvalue = this->symbol_map.find(statement->lvalue());
-        auto statement_location = elna_gcc_location(&statement->position());
+        auto statement_location = get_location(&statement->position());
 
         if (lvalue == this->symbol_map.end())
         {
@@ -170,11 +238,11 @@ namespace gcc
 
         if (TREE_TYPE(this->current_expression) != TREE_TYPE(lvalue->second))
         {
-            error_at(elna_gcc_location(&statement->position()),
+            error_at(get_location(&statement->position()),
                     "cannot assign value of type %s to variable '%s' of type %s",
-                    elna_gcc_print_type(TREE_TYPE(this->current_expression)),
+                    print_type(TREE_TYPE(this->current_expression)),
                     statement->lvalue().c_str(),
-                    elna_gcc_print_type(TREE_TYPE(lvalue->second)));
+                    print_type(TREE_TYPE(lvalue->second)));
             this->current_expression = error_mark_node;
             return;
         }
@@ -184,5 +252,102 @@ namespace gcc
         append_to_statement_list(assignment, &this->current_statements);
         this->current_expression = NULL_TREE;
     }
+
+    void generic_visitor::visit(source::if_statement *statement)
+    {
+        statement->prerequisite().accept(this);
+
+        if (TREE_TYPE(this->current_expression) != boolean_type_node)
+        {
+            error_at(get_location(&statement->prerequisite().position()),
+                    "expected expression of boolean type but its type is %s",
+                    print_type(TREE_TYPE(this->current_expression)));
+            this->current_expression = error_mark_node;
+            return;
+        }
+        auto then_location = get_location(&statement->body().position());
+        auto prerequisite_location = get_location(&statement->prerequisite().position());
+
+        auto then_label_decl = build_label_decl("then", then_location);
+        auto endif_label_decl = build_label_decl("end_if", then_location);
+
+        auto goto_then = build1_loc(prerequisite_location, GOTO_EXPR,
+                void_type_node, then_label_decl);
+        auto goto_endif = build1_loc(prerequisite_location, GOTO_EXPR,
+                void_type_node, endif_label_decl);
+
+        auto cond_expr = build3_loc(prerequisite_location, COND_EXPR,
+                void_type_node, this->current_expression, goto_then, goto_endif);
+        append_to_statement_list(cond_expr, &this->current_statements);
+
+        auto then_label_expr = build1_loc(then_location, LABEL_EXPR,
+                void_type_node, then_label_decl);
+        append_to_statement_list(then_label_expr, &this->current_statements);
+
+        statement->body().accept(this);
+
+        auto endif_label_expr = build1(LABEL_EXPR, void_type_node, endif_label_decl);
+        append_to_statement_list(endif_label_expr, &this->current_statements);
+
+        this->current_expression = NULL_TREE;
+    }
+
+    tree generic_visitor::build_label_decl(const char *name, location_t loc)
+    {
+        auto label_decl = build_decl(loc,
+                LABEL_DECL, get_identifier(name), void_type_node);
+
+        DECL_CONTEXT(label_decl) = this->main_fndecl;
+
+        return label_decl;
+    }
+
+    void generic_visitor::visit(source::while_statement *statement)
+    {
+        statement->prerequisite().accept(this);
+
+        if (TREE_TYPE(this->current_expression) != boolean_type_node
+                && TREE_TYPE(this->current_expression) != integer_type_node)
+        {
+            error_at(get_location(&statement->prerequisite().position()),
+                    "expected expression of boolean type but its type is %s",
+                    print_type(TREE_TYPE(this->current_expression)));
+            this->current_expression = error_mark_node;
+            return;
+        }
+        auto prerequisite_location = get_location(&statement->prerequisite().position());
+        auto body_location = get_location(&statement->body().position());
+
+        auto prerequisite_label_decl = build_label_decl("while_check", prerequisite_location);
+        auto prerequisite_label_expr = build1_loc(prerequisite_location, LABEL_EXPR,
+                void_type_node, prerequisite_label_decl);
+        append_to_statement_list(prerequisite_label_expr, &this->current_statements);
+
+        auto body_label_decl = build_label_decl("while_body", body_location);
+        auto end_label_decl = build_label_decl("end_while", UNKNOWN_LOCATION);
+
+        auto goto_body = build1_loc(prerequisite_location, GOTO_EXPR,
+                void_type_node, body_label_decl);
+        auto goto_end = build1_loc(prerequisite_location, GOTO_EXPR,
+                void_type_node, end_label_decl);
+
+        auto cond_expr = build3_loc(prerequisite_location, COND_EXPR,
+                void_type_node, this->current_expression, goto_body, goto_end);
+        append_to_statement_list(cond_expr, &this->current_statements);
+
+        auto body_label_expr = build1_loc(body_location, LABEL_EXPR,
+                void_type_node, body_label_decl);
+        append_to_statement_list(body_label_expr, &this->current_statements);
+
+        statement->body().accept(this);
+
+        auto goto_check = build1(GOTO_EXPR, void_type_node, prerequisite_label_decl);
+        append_to_statement_list(goto_check, &this->current_statements);
+
+        auto endif_label_expr = build1(LABEL_EXPR, void_type_node, end_label_decl);
+        append_to_statement_list(endif_label_expr, &this->current_statements);
+
+        this->current_expression = NULL_TREE;
+    }
 }
 }

gcc/elna1.cc

@@ -92,7 +92,7 @@ static void elna_parse_file (const char *filename)
     {
         for (const auto& error : driver.errors())
         {
-            auto gcc_location = elna_gcc_location(&error->position);
+            auto gcc_location = elna::gcc::get_location(&error->position);
 
             error_at(gcc_location, error->what().c_str());
         }

include/elna/gcc/elna-diagnostic.h

@@ -8,6 +8,12 @@
 
 #include "elna/source/result.h"
 
-location_t elna_gcc_location(const elna::source::position *position);
+namespace elna
+{
+namespace gcc
+{
+    location_t get_location(const elna::source::position *position);
 
-const char *elna_gcc_print_type(tree type);
+    const char *print_type(tree type);
+}
+}

include/elna/gcc/elna-generic.h

@@ -20,6 +20,9 @@ namespace gcc
         tree current_statements{ NULL_TREE };
         tree current_expression{ NULL_TREE };
         std::unordered_map<std::string, tree> symbol_map;
+        tree main_fndecl{ NULL_TREE };
+
+        tree build_label_decl (const char *name, location_t loc);
 
     public:
         void visit(source::program *program) override;
@@ -30,6 +33,8 @@ namespace gcc
         void visit(source::declaration *declaration) override;
         void visit(source::variable_expression *expression) override;
         void visit(source::assign_statement *statement) override;
+        void visit(source::if_statement *statement) override;
+        void visit(source::while_statement *statement) override;
     };
 }
 }

include/elna/source/ast.h

@@ -486,5 +486,7 @@ namespace source
         expression& operand();
         unary_operator operation() const noexcept;
     };
+
+    const char *print_binary_operator(const binary_operator operation);
 }
 }

source/ast.cc

@@ -525,5 +525,32 @@ namespace source
     {
         return *m_body;
     }
+
+    const char *print_binary_operator(const binary_operator operation)
+    {
+        switch (operation)
+        {
+            case binary_operator::sum:
+                return "+";
+            case binary_operator::subtraction: 
+                return "-";
+            case binary_operator::multiplication:
+                return "*";
+            case binary_operator::division:
+                return "/";
+            case binary_operator::equals:
+                return "=";
+            case binary_operator::not_equals:
+                return "/=";
+            case binary_operator::less:
+                return "<";
+            case binary_operator::less_equal:
+                return "<=";
+            case binary_operator::greater:
+                return ">";
+            case binary_operator::greater_equal:
+                return ">=";
+        }
+    };
 }
 }