path: root/c_parser/src/c_parser.y

%code requires{

#include "ast.hpp"
extern ast_Top *g_root; // A way of getting the AST out

//! This is to fix problems when generating C++
// We are declaring the functions provided by Flex, so
// that Bison generated code can call them.
int yylex(void);
void yyerror(const char *);

}

// Represents the value associated with any kind of
// AST node.
%union{
    const ast_Base *stmnt;
    double number;
    std::string *string;
}
                        
%token T_TYPE_SPEC T_TYPE_QUAL T_STRG_SPEC T_IDENTIFIER
%token T_SC T_CMA T_LRB T_RRB T_LCB T_RCB T_LSB T_RSB T_QU T_COL T_LOG_OR T_LOG_AND T_OR T_XOR T_AND T_EQUALITY_OP T_REL_OP T_SHIFT_OP T_MULT T_DIV T_REM T_TILDE T_NOT T_DOT T_ARROW T_INCDEC T_ADDSUB_OP T_ASSIGN_OPER T_EQ T_SIZEOF
%token T_INT_CONST
%token T_IF T_ELSE T_WHILE T_DO T_FOR T_RETURN
                        
%type <stmnt> EXT_DEF EXT_DECLARATION
%type <stmnt> FUNC_DEF PARAMETER_LIST PARAMETER PARAM_DECLARATOR
%type <stmnt> DECLARATION_LIST DECLARATION DECLARATION_SPEC DECLARATION_SPEC_T INIT_DECLARATOR INIT_DECLARATOR_LIST DECLARATOR
%type <stmnt> STATEMENT_LIST STATEMENT COMPOUND_STATEMENT COMPOUND_STATEMENT_2 SELECTION_STATEMENT SELECTION_STATEMENT_2 EXPRESSION_STATEMENT JUMP_STATEMENT ITERATION_STATEMENT
%type <stmnt> EXPRESSION ASSIGNMENT_EXPRESSION CONDITIONAL_EXPRESSION LOGICAL_OR_EXPRESSION LOGICAL_AND_EXPRESSION INCLUSIVE_OR_EXPRESSION EXCLUSIVE_OR_EXPRESSION AND_EXPRESSION EQUALITY_EXPRESSION RELATIONAL_EXPRESSION SHIFT_EXPRESSION ADDITIVE_EXPRESSION MULTIPLICATIVE_EXPRESSION CAST_EXPRESSION UNARY_EXPRESSION POSTFIX_EXPRESSION POSTFIX_EXPRESSION_2 ARGUMENT_EXPRESSION_LIST PRIMARY_EXPRESSION
%type <number> CONSTANT T_INT_CONST
%type <string> T_IDENTIFIER MULTDIVREM_OP UNARY_OPERATOR ASSIGN_OPER T_ASSIGN_OPER T_EQ T_AND T_ADDSUB_OP T_TILDE T_NOT T_MULT T_DIV T_REM //T_OPERATOR
                        
%start ROOT
                        
%%

ROOT:
		EXT_DEF { ; }
		;

// EXTERNAL DEFINITION

EXT_DEF:
		EXT_DECLARATION { g_root->push($1); }
        |       EXT_DEF EXT_DECLARATION { g_root->push($2); }
		;

EXT_DECLARATION:
		DECLARATION { $$ = $1; }
        |       FUNC_DEF { $$ = $1; }
		;

// FUNCTION DEFINITION

FUNC_DEF:
		DECLARATION_SPEC T_IDENTIFIER T_LRB PARAMETER_LIST T_RRB COMPOUND_STATEMENT { $$ = new ast_Function(*$2, $4, $6); }
		;

PARAMETER_LIST:
		%empty { $$ = new ast_ParamList(); }
	| 	PARAMETER { $$ = new ast_ParamList($1); }
	|	PARAMETER_LIST T_CMA PARAMETER { $$->push($3); }
		;

PARAMETER:
		DECLARATION_SPEC PARAM_DECLARATOR { $$ = $2; }
		;

PARAM_DECLARATOR:
		T_IDENTIFIER { $$ = new ast_Parameter(*$1);}
		;

// DECLARATION

DECLARATION_LIST:
		DECLARATION { $$ = new ast_DeclarationList($1); }
	|	DECLARATION_LIST DECLARATION { $$->push($2); }
		;

DECLARATION:
		DECLARATION_SPEC INIT_DECLARATOR_LIST T_SC { $$ = $2; }
		;

DECLARATION_SPEC:
		DECLARATION_SPEC_T { ; }
	|	DECLARATION_SPEC_T DECLARATION_SPEC { ; }
		;

DECLARATION_SPEC_T:
		T_TYPE_SPEC { ; }
	|	T_TYPE_QUAL { ; }
	|	T_STRG_SPEC { ; }
		;

INIT_DECLARATOR_LIST:
		INIT_DECLARATOR { $$ = new ast_VariableDeclaration($1); }
	|       INIT_DECLARATOR_LIST T_CMA INIT_DECLARATOR { $$->push($3); }
		;

INIT_DECLARATOR:
		DECLARATOR { ; }
	|	DECLARATOR T_EQ ASSIGNMENT_EXPRESSION { ; }
		;

DECLARATOR:
		T_IDENTIFIER {$$ = new ast_Variable(*$1); }
		;

// STATEMENT

STATEMENT_LIST:
		STATEMENT { $$ = new ast_StatementList($1); }
	|	STATEMENT_LIST STATEMENT { $$->push($2); }
		;

STATEMENT:
		COMPOUND_STATEMENT { $$ = $1; }
	|	SELECTION_STATEMENT { $$ = $1; }
	|	EXPRESSION_STATEMENT { $$ = $1; }
	|	JUMP_STATEMENT { $$ = $1; }
	|	ITERATION_STATEMENT { $$ = $1; }
		;

COMPOUND_STATEMENT:
		T_LCB COMPOUND_STATEMENT_2 { $$ = $2; }
		;

COMPOUND_STATEMENT_2:
		T_RCB { $$ = new ast_CompoundStatement; }
	|	DECLARATION_LIST T_RCB { $$ = new ast_CompoundStatement($1); }
	|	DECLARATION_LIST STATEMENT_LIST T_RCB { $$ = new ast_CompoundStatement($1, $2); }
	|	STATEMENT_LIST T_RCB { $$ = new ast_CompoundStatement($1); }
		;

SELECTION_STATEMENT:
		T_IF T_LRB EXPRESSION T_RRB STATEMENT SELECTION_STATEMENT_2 { $$ = new ast_SelectionStatement($5, $6); }
		;

SELECTION_STATEMENT_2:
		%empty { $$ = new ast_SelectionStatement(); }
	|	T_ELSE STATEMENT { $$ = $2; }
		;

EXPRESSION_STATEMENT:
		T_SC { $$ = new ast_ExpressionStatement(); }
	|	EXPRESSION T_SC { $$ = $1; }
		;

JUMP_STATEMENT:
		T_RETURN EXPRESSION_STATEMENT { $$ = $2; }
		;

ITERATION_STATEMENT:
		T_WHILE T_LRB EXPRESSION T_RRB STATEMENT { $$ = $5; }
	|	T_DO STATEMENT T_WHILE T_LRB EXPRESSION T_RRB T_SC { $$ = $2; }
	|	T_FOR T_LRB EXPRESSION T_SC EXPRESSION T_SC EXPRESSION T_RRB STATEMENT { $$ = $9; }
		;

// Expressions

EXPRESSION:
		ASSIGNMENT_EXPRESSION { $$ = $1; }
		;

ASSIGNMENT_EXPRESSION:
		CONDITIONAL_EXPRESSION { $$ = $1; }
	|	UNARY_EXPRESSION ASSIGN_OPER ASSIGNMENT_EXPRESSION { $$ = $1; }
		;

ASSIGN_OPER:
		T_ASSIGN_OPER { ; }
	|	T_EQ { ; }
	;

CONDITIONAL_EXPRESSION:
		LOGICAL_OR_EXPRESSION { $$ = $1; }
	|	LOGICAL_OR_EXPRESSION T_QU EXPRESSION T_COL CONDITIONAL_EXPRESSION { $$ = $1; }
		;

LOGICAL_OR_EXPRESSION:
		LOGICAL_AND_EXPRESSION { $$ = $1; }
	|	LOGICAL_OR_EXPRESSION T_LOG_OR LOGICAL_AND_EXPRESSION { $$ = $3; }
		;

LOGICAL_AND_EXPRESSION:
		INCLUSIVE_OR_EXPRESSION { $$ = $1; }
	|	LOGICAL_AND_EXPRESSION T_LOG_AND INCLUSIVE_OR_EXPRESSION { $$ = $3; }
		;

INCLUSIVE_OR_EXPRESSION:
		EXCLUSIVE_OR_EXPRESSION { $$ = $1; }
	|	INCLUSIVE_OR_EXPRESSION T_OR EXCLUSIVE_OR_EXPRESSION { $$ = $3; }
		;

EXCLUSIVE_OR_EXPRESSION:
		AND_EXPRESSION { $$ = $1; }
	|	EXCLUSIVE_OR_EXPRESSION T_XOR AND_EXPRESSION { $$ = $3; }
		;

AND_EXPRESSION:
		EQUALITY_EXPRESSION { $$ = $1; }
	|	AND_EXPRESSION T_AND EQUALITY_EXPRESSION { $$ = $3; }
		;

EQUALITY_EXPRESSION:
		RELATIONAL_EXPRESSION { $$ = $1; }
	|	EQUALITY_EXPRESSION T_EQUALITY_OP RELATIONAL_EXPRESSION { $$ = $3; }
		;

RELATIONAL_EXPRESSION:
		SHIFT_EXPRESSION { $$ = $1; }
	|	RELATIONAL_EXPRESSION T_REL_OP SHIFT_EXPRESSION { $$ = $3; }
		;

SHIFT_EXPRESSION:
		ADDITIVE_EXPRESSION { $$ = $1; }
	|	SHIFT_EXPRESSION T_SHIFT_OP ADDITIVE_EXPRESSION { $$ = $3; }
		;

ADDITIVE_EXPRESSION:
		MULTIPLICATIVE_EXPRESSION { $$ = $1; }
	|	ADDITIVE_EXPRESSION T_ADDSUB_OP MULTIPLICATIVE_EXPRESSION { $$ = $3; }
		;

MULTIPLICATIVE_EXPRESSION:
		CAST_EXPRESSION { $$ = $1; }
	|	MULTIPLICATIVE_EXPRESSION MULTDIVREM_OP CAST_EXPRESSION { $$ = $3; }
		;

MULTDIVREM_OP:
		T_MULT { $$ = $1; }
	|	T_DIV { $$ = $1; }
	|	T_REM { $$ = $1; }
	;

CAST_EXPRESSION:
		UNARY_EXPRESSION { $$ = $1; }
	|	T_LRB T_TYPE_SPEC T_RRB CAST_EXPRESSION { $$ = $4; }
	;

UNARY_EXPRESSION:
		POSTFIX_EXPRESSION { $$ = $1; }
	|	T_INCDEC UNARY_EXPRESSION { $$ = $2; }
	|	UNARY_OPERATOR CAST_EXPRESSION { $$ = $2; }
	|	T_SIZEOF UNARY_EXPRESSION { $$ = $2; }
	|	T_SIZEOF T_LRB T_TYPE_SPEC T_RRB { $$ = new ast_Expression(); }
	;

UNARY_OPERATOR:
		T_AND { $$ = $1; }
	|	T_ADDSUB_OP { $$ = $1; }
	|	T_MULT { $$ = $1; }
	|	T_TILDE { $$ = $1; }
	|	T_NOT { $$ = $1; }
	;

POSTFIX_EXPRESSION:
		PRIMARY_EXPRESSION { $$ = $1; }
	|	POSTFIX_EXPRESSION T_LSB EXPRESSION T_RSB { $$ = $3; }
	|	POSTFIX_EXPRESSION T_LRB POSTFIX_EXPRESSION_2 { $$ = $3; }
	|	POSTFIX_EXPRESSION T_DOT T_IDENTIFIER { $$ = new ast_Expression(); }
	|	POSTFIX_EXPRESSION T_ARROW T_IDENTIFIER { $$ = new ast_Expression(); }
	|	POSTFIX_EXPRESSION T_INCDEC { $$ = new ast_Expression(); }
	;

POSTFIX_EXPRESSION_2:
		T_RRB { $$ = new ast_Expression(); }
	|	ARGUMENT_EXPRESSION_LIST T_RRB { $$ = $1; }
	;

ARGUMENT_EXPRESSION_LIST:
		ASSIGNMENT_EXPRESSION { $$ = $1; }
	|	ARGUMENT_EXPRESSION_LIST T_CMA ASSIGNMENT_EXPRESSION { $$ = $3; }
	;

PRIMARY_EXPRESSION:
		T_IDENTIFIER { $$ = new ast_Expression(); }
	|	CONSTANT { $$ = new ast_Expression(); }
	|	T_LRB EXPRESSION T_RRB { $$ = $2; }
	;

CONSTANT:
		T_INT_CONST { $$ = $1; }
	;

%%

ast_Top *g_root; // Definition of variable (to match declaration earlier)

ast_Top *parseAST() {
    g_root = new ast_Top;
    yyparse();
    return g_root;
}