matiec: comparison stage1

equal deleted inserted replaced

-:8ffa211b7f9a
+:90782e241346
 /*********************/
 /* B 1.2 - Constants */
 /*********************/
 %type <leaf>	constant
-/* a helper symbol for expression */
+%type <leaf>	non_negative_constant
-%type  <leaf> non_negative_constant
 /******************************/
 /* B 1.2.1 - Numeric Literals */
 /******************************/
 /* Done totally within flex...
 bit
 */
 %type  <leaf> numeric_literal
-/* helper symbol for non_negative_constant */
-%type  <leaf> non_negative_numeric_literal
 %type  <leaf> integer_literal
 %type  <leaf> signed_integer
-/* a helper symbol for non_negative_constant */
-%type  <leaf> non_negative_signed_integer
 %token <ID>   integer_token
 %type  <leaf> integer
 %token <ID>   binary_integer_token
 %type  <leaf> binary_integer
 %token <ID>   octal_integer_token
 %token <ID>   hex_integer_token
 %type  <leaf> hex_integer
 %token <ID>   real_token
 %type  <leaf> real
 %type  <leaf> signed_real
-/* helper symbol for non_negative_real_literal */
-%type  <leaf> non_negative_signed_real
 %type  <leaf> real_literal
-/* helper symbol for non_negative_numeric_literal */
-%type  <leaf> non_negative_real_literal
 // %type  <leaf> exponent
 %type  <leaf> bit_string_literal
 %type  <leaf> boolean_literal
+%token safeboolean_true_literal_token
+%token safeboolean_false_literal_token
+%token boolean_true_literal_token
+%token boolean_false_literal_token
 %token FALSE
 %token TRUE
 %token <ID>	fixed_point_s_token
 %token <ID>	integer_s_token
 %token <ID>	fixed_point_ms_token
 %token <ID>	integer_ms_token
-%token TIME
+// %token TIME
 %token T_SHARP
 /************************************/
 /* B 1.2.3.2 - Time of day and Date */
 %type  <leaf>	year
 %type  <leaf>	month
 %type  <leaf>	day
 %type  <leaf>	date_and_time
-%token TIME_OF_DAY
+// %token TIME_OF_DAY
-%token DATE
+// %token DATE
 %token D_SHARP
-%token DATE_AND_TIME
+// %token DATE_AND_TIME
 /**********************/
 /* B 1.3 - Data Types */
 /**********************/
 %token WSTRING
 %token STRING
 %token BOOL
-// %token TIME
+%token TIME
-// %token DATE
+%token DATE
-// %token DATE_AND_TIME
+%token DATE_AND_TIME
 %token DT
-// %token TIME_OF_DAY
+%token TIME_OF_DAY
 %token TOD
+/******************************************************/
+/* Symbols defined in                                 */
+/* "Safety Software Technical Specification,          */
+/*  Part 1: Concepts and Function Blocks,             */
+/*  Version 1.0 – Official Release"                   */
+/* by PLCopen - Technical Committee 5 - 2006-01-31    */
+/******************************************************/
+%token SAFEBYTE
+%token SAFEWORD
+%token SAFEDWORD
+%token SAFELWORD
+%token SAFELREAL
+%token SAFEREAL
+%token SAFESINT
+%token SAFEINT
+%token SAFEDINT
+%token SAFELINT
+%token SAFEUSINT
+%token SAFEUINT
+%token SAFEUDINT
+%token SAFEULINT
+%token SAFEWSTRING
+%token SAFESTRING
+%token SAFEBOOL
+%token SAFETIME
+%token SAFEDATE
+%token SAFEDATE_AND_TIME
+%token SAFEDT
+%token SAFETIME_OF_DAY
+%token SAFETOD
 /********************************/
 /* B 1.3.2 - Generic data types */
 /********************************/
 /* Strangely, the following symbol does seem to be required! */
 // %type  <leaf>	multiply_operator
 %type  <leaf>	power_expression
 %type  <leaf>	unary_expression
 // %type  <leaf>	unary_operator
 %type  <leaf>	primary_expression
+%type  <leaf>	non_negative_primary_expression
 /* intermediate helper symbol for primary_expression */
 %type  <leaf>	function_invocation
 // %token AND
 // %token XOR
 %token UNTIL
 %token END_REPEAT
 %token EXIT
-/******************************************************/
-/* Symbols defined in                                 */
-/* "Safety Software Technical Specification,          */
-/*  Part 1: Concepts and Function Blocks,             */
-/*  Version 1.0 – Official Release"                   */
-/* by PLCopen - Technical Committee 5 - 2006-01-31    */
-/******************************************************/
-%token SAFEBOOL
 %%
 | character_string
 | time_literal
 | bit_string_literal
 | boolean_literal
 /* NOTE: in order to remove reduce/reduce conflicts,
+* [between -9.5 being parsed as
+*     (i)   a signed real,
+*     (ii)  or as a real preceded by the '-' operator
+*  ]
+*  we need to define a variant of the constant construct
+*  where any constant is never preceded by the '-' character.
+* In order to do this, we have borugh the signed_real
+* directly into the definition of the constant construct
+* (so we can define another non_negative_constant
+* construct that does not include it!)
+*/
+| signed_real
+/* NOTE: in order to remove reduce/reduce conflicts,
 * unsigned_integer, signed_integer, binary_integer, octal_integer
 * and hex_integer have been integrated directly into
 * the constants construct, instead of belonging to
-* either the bit_string_literal or integer_literal
+* both the bit_string_literal or integer_literal
 * construct.
 */
 /* NOTE: unsigned_integer, although used in some
 * rules, is not defined in the spec!
 * We therefore replaced unsigned_integer as integer
 | binary_integer
 | octal_integer
 | hex_integer
 ;
-/* a helper symbol for expression */
-/* A constant without any preceding '-', but may
+/* NOTE: in order to remove reduce/reduce conflicts,
-* include a preceding '+' !
+* [between -9.5 being parsed as
+*     (i)   a signed real,
+*     (ii)  or as a real preceded by the '-' operator
+*  ]
+*  we need to define a variant of the constant construct
+*  where any constant is never preceded by the '-' character.
+* In order to do this, we have borugh the signed_real
+* directly into the definition of the constant construct
+* (so we can define another non_negative_constant
+* construct that does not include it!)
 */
 non_negative_constant:
-non_negative_numeric_literal
+numeric_literal
 | character_string
 | time_literal
 | bit_string_literal
 | boolean_literal
-| non_negative_signed_integer
+/* NOTE: in order to remove reduce/reduce conflicts,
+* [between -9.5 being parsed as
+*     (i)   a signed real,
+*     (ii)  or as a real preceded by the '-' operator
+*  ]
+*  we need to define a variant of the constant construct
+*  where any constant is never preceded by the '-' character.
+* In order to do this, we have borugh the signed_real
+* directly into the definition of the constant construct
+* (so we can define another non_negative_constant
+* construct that does not include it!)
+*/
+/* | signed_real */
+| real /* an unsigned real */
+/* NOTE: in order to remove reduce/reduce conflicts,
+* unsigned_integer, signed_integer, binary_integer, octal_integer
+* and hex_integer have been integrated directly into
+* the constants construct, instead of belonging to
+* both the bit_string_literal or integer_literal
+* construct.
+*/
+/* NOTE: unsigned_integer, although used in some
+* rules, is not defined in the spec!
+* We therefore replaced unsigned_integer as integer
+*/
+| integer  /* i.e. an unsigned_integer */
+/* | signed_integer */
 | binary_integer
 | octal_integer
 | hex_integer
 ;
 /******************************/
 /* B 1.2.1 - Numeric Literals */
 /******************************/
 *      real_literal: [real_type_name '#'] singned_real
 *      signed_real: ['+'|'-'] real
 *      Flex handles real, while bison handles signed_real
 *      and real_literal.
 *
-*    - According to the spec, intger '.' integer
+*    - According to the spec, integer '.' integer
 *      may be reduced to either a real or a fixed_point.
 *      It is nevertheless possible to figure out from the
 *      context which of the two rules should be used in
 *      the reduction.
 *      Unfortunately, due to the issue described above
 numeric_literal:
 integer_literal
 | real_literal
 ;
-/* helper symbol for non_negative_constant */
-non_negative_numeric_literal:
-integer_literal
-| non_negative_real_literal
-;
 integer_literal:
 integer_type_name '#' signed_integer
 	{$$ = new integer_literal_c($1, $3, locf(@1), locl(@3));}
 | integer_type_name '#' binary_integer
 ;
 signed_integer:
 integer
 | '+' integer   {$$ = $2;}
-| '-' integer	{$$ = new neg_literal_c($2, locloc(@$));}
+| '-' integer	{$$ = new neg_integer_c($2, locloc(@$));}
-;
-/* a helper symbol for non_negative_constant */
-/* A integer without any preceding '-', but may
-* include a preceding '+' !
-*/
-non_negative_signed_integer:
-integer
-| '+' integer   {$$ = $2;}
 ;
 real_literal:
-signed_real
+/* NOTE: see note in the definition of constant for reason
-| real_type_name '#' signed_real
+* why signed_real is missing here!
+*/
+/*  signed_real */
+real_type_name '#' signed_real
 	{$$ = new real_literal_c($1, $3, locf(@1), locl(@3));}
 /* ERROR_CHECK_BEGIN */
 | real_type_name signed_real
 	{$$ = NULL; print_err_msg(locl(@1), locf(@2), "'#' missing between real type name and value in real literal."); yynerrs++;}
 | real_type_name '#' error
 	 yyerrok;
 	}
 /* ERROR_CHECK_END */
 ;
-/* helper symbol for non_negative_numeric_literal */
-non_negative_real_literal:
-non_negative_signed_real
-| real_type_name '#' signed_real
-	{$$ = new real_literal_c($1, $3, locf(@1), locl(@3));}
-;
 signed_real:
 real
 | '+' real	{$$ = $2;}
-| '-' real	{$$ = new neg_literal_c($2, locloc(@2));}
+| '-' real	{$$ = new neg_real_c($2, locloc(@2));}
 ;
-/* helper symbol for non_negative_real_literal */
-non_negative_signed_real:
-real
-| '+' real	{$$ = $2;}
-;
 bit_string_literal:
 bit_string_type_name '#' integer  /* i.e. unsigned_integer */
 	{$$ = new bit_string_literal_c($1, $3, locf(@1), locl(@3));}
 | bit_string_type_name octal_integer
 	{$$ = NULL; print_err_msg(locl(@1), locf(@2), "'#' missing between bit string type name and value in bit string literal."); yynerrs++;}
 | bit_string_type_name hex_integer
 	{$$ = NULL; print_err_msg(locl(@1), locf(@2), "'#' missing between bit string type name and value in bit string literal."); yynerrs++;}
 | bit_string_type_name '#' error
-{$$ = NULL;
+	{$$ = NULL;
 	 if (is_current_syntax_token()) {print_err_msg(locl(@2), locf(@3), "no value defined for bit string literal.");}
 	 else {print_err_msg(locf(@3), locl(@3), "invalid value for bit string literal."); yyclearin;}
 	 yyerrok;
 	}
 /* ERROR_CHECK_END */
 ;
 boolean_literal:
-TRUE	{$$ = new boolean_literal_c(new bool_type_name_c(locloc(@$)),
+boolean_true_literal_token
-				    new boolean_true_c(locloc(@$)),
+	{$$ = new boolean_literal_c(new bool_type_name_c(locloc(@$)),
-				    locloc(@$));}
+				    new boolean_true_c(locloc(@$)),
-| FALSE	{$$ = new boolean_literal_c(new bool_type_name_c(locloc(@$)),
+				    locloc(@$));
+	}
+| boolean_false_literal_token
+	{$$ = new boolean_literal_c(new bool_type_name_c(locloc(@$)),
 				    new boolean_false_c(locloc(@$)),
-				    locloc(@$));}
+				    locloc(@$));
+	}
+| safeboolean_true_literal_token
+	{$$ = new boolean_literal_c(new safebool_type_name_c(locloc(@$)),
+				    new boolean_true_c(locloc(@$)),
+				    locloc(@$));
+	}
+| safeboolean_false_literal_token
+	{$$ = new boolean_literal_c(new safebool_type_name_c(locloc(@$)),
+				    new boolean_false_c(locloc(@$)),
+				    locloc(@$));
+	}
+| FALSE
+	{$$ = new boolean_literal_c(NULL,
+				    new boolean_false_c(locloc(@$)),
+				    locloc(@$));
+	}
+| TRUE
+	{$$ = new boolean_literal_c(NULL,
+				    new boolean_true_c(locloc(@$)),
+				    locloc(@$));
+	}
 /*
 |	BOOL '#' '1' {}
 |	BOOL '#' '0' {}
 */
 /* NOTE: the rules
 *
 *       We therefore have flex returning the token T_SHARP
 *       when it comes across 'T#'
 */
 TIME '#' interval
-	{$$ = new duration_c(NULL, $3, locloc(@$));}
+	{$$ = new duration_c(new time_type_name_c(locloc(@1)), NULL, $3, locloc(@$));}
 | TIME '#' '-' interval
-	{$$ = new duration_c(new neg_time_c(locloc(@$)), $4, locloc(@$));}
+	{$$ = new duration_c(new time_type_name_c(locloc(@1)), new neg_time_c(locloc(@$)), $4, locloc(@$));}
 | T_SHARP interval
-	{$$ = new duration_c(NULL, $2, locloc(@$));}
+	{$$ = new duration_c(new time_type_name_c(locloc(@1)), NULL, $2, locloc(@$));}
 | T_SHARP '-' interval
-	{$$ = new duration_c(new neg_time_c(locloc(@$)), $3, locloc(@$));}
+	{$$ = new duration_c(new time_type_name_c(locloc(@1)), new neg_time_c(locloc(@$)), $3, locloc(@$));}
+| SAFETIME '#' interval
+	{$$ = new duration_c(new safetime_type_name_c(locloc(@1)), NULL, $3, locloc(@$));}
+| SAFETIME '#' '-' interval
+	{$$ = new duration_c(new safetime_type_name_c(locloc(@1)), new neg_time_c(locloc(@$)), $4, locloc(@$));}
 /* ERROR_CHECK_BEGIN */
 | TIME interval
 	{$$ = NULL; print_err_msg(locl(@1), locf(@2), "'#' missing between 'TIME' and interval in duration."); yynerrs++;}
 | TIME '-' interval
 	{$$ = NULL; print_err_msg(locl(@1), locf(@2), "'#' missing between 'TIME' and interval in duration."); yynerrs++;}
 /************************************/
 /* B 1.2.3.2 - Time of day and Date */
 /************************************/
 time_of_day:
 TIME_OF_DAY '#' daytime
-	{$$ = new time_of_day_c($3, locloc(@$));}
+	{$$ = new time_of_day_c(new tod_type_name_c(locloc(@1)), $3, locloc(@$));}
+| SAFETIME_OF_DAY '#' daytime
+	{$$ = new time_of_day_c(new safetod_type_name_c(locloc(@1)), $3, locloc(@$));}
 /* ERROR_CHECK_BEGIN */
 | TIME_OF_DAY daytime
 	{$$ = NULL; print_err_msg(locl(@1), locf(@2), "'#' missing between 'TIME_OF_DAY' and daytime in time of day."); yynerrs++;}
 | TIME_OF_DAY '#' error
 	{$$ = NULL;
 day_second: fixed_point;
 date:
 DATE '#' date_literal
-	{$$ = new date_c($3, locloc(@$));}
+	{$$ = new date_c(new date_type_name_c(locloc(@1)), $3, locloc(@$));}
 | D_SHARP date_literal
-	{$$ = new date_c($2, locloc(@$));}
+	{$$ = new date_c(new date_type_name_c(locloc(@1)), $2, locloc(@$));}
+| SAFEDATE '#' date_literal
+	{$$ = new date_c(new safedate_type_name_c(locloc(@1)), $3, locloc(@$));}
 /* ERROR_CHECK_BEGIN */
 | DATE date_literal
 	{$$ = NULL; print_err_msg(locl(@1), locf(@2), "'#' missing between 'DATE' and date literal in date."); yynerrs++;}
 | DATE '#' error
 	{$$ = NULL;
 day: integer;
 date_and_time:
 DATE_AND_TIME '#' date_literal '-' daytime
-	{$$ = new date_and_time_c($3, $5, locloc(@$));}
+	{$$ = new date_and_time_c(new dt_type_name_c(locloc(@1)), $3, $5, locloc(@$));}
+| SAFEDATE_AND_TIME '#' date_literal '-' daytime
+	{$$ = new date_and_time_c(new safedt_type_name_c(locloc(@1)), $3, $5, locloc(@$));}
 /* ERROR_CHECK_BEGIN */
 | DATE_AND_TIME date_literal '-' daytime
 	{$$ = NULL; print_err_msg(locl(@1), locf(@2), "'#' missing between 'DATE_AND_TIME' and date literal in date and time."); yynerrs++;}
 | DATE_AND_TIME '#' '-' daytime
 	{$$ = NULL; print_err_msg(locl(@2), locf(@3), "no value defined for date literal in date and time."); yynerrs++;}
 /***********************************/
 /* B 1.3.1 - Elementary Data Types */
 /***********************************/
+/******************************************************/
+/* SAFExxxx Symbols defined in                        */
+/* "Safety Software Technical Specification,          */
+/*  Part 1: Concepts and Function Blocks,             */
+/*  Version 1.0 – Official Release"                   */
+/* by PLCopen - Technical Committee 5 - 2006-01-31    */
+/******************************************************/
 elementary_type_name:
 numeric_type_name
 | date_type_name
 | bit_string_type_name
 | elementary_string_type_name
 | BOOL		{$$ = new bool_type_name_c(locloc(@$));}
 /* NOTE: see note under the B 1.2.1 section of token
 * and grouping type definition for reason why BOOL
 * was added to this definition.
 */
-/******************************************************/
+| SAFETIME	{$$ = new safetime_type_name_c(locloc(@$));}
-/* Symbols defined in                                 */
-/* "Safety Software Technical Specification,          */
-/*  Part 1: Concepts and Function Blocks,             */
-/*  Version 1.0 – Official Release"                   */
-/* by PLCopen - Technical Committee 5 - 2006-01-31    */
-/******************************************************/
 | SAFEBOOL	{$$ = new safebool_type_name_c(locloc(@$));}
 ;
 numeric_type_name:
 integer_type_name
 signed_integer_type_name
 | unsigned_integer_type_name
 ;
 signed_integer_type_name:
-SINT	{$$ = new sint_type_name_c(locloc(@$));}
+SINT		{$$ = new sint_type_name_c(locloc(@$));}
-| INT	{$$ = new int_type_name_c(locloc(@$));}
+| INT		{$$ = new int_type_name_c(locloc(@$));}
-| DINT	{$$ = new dint_type_name_c(locloc(@$));}
+| DINT		{$$ = new dint_type_name_c(locloc(@$));}
-| LINT	{$$ = new lint_type_name_c(locloc(@$));}
+| LINT		{$$ = new lint_type_name_c(locloc(@$));}
+| SAFESINT	{$$ = new safesint_type_name_c(locloc(@$));}
+| SAFEINT	{$$ = new safeint_type_name_c(locloc(@$));}
+| SAFEDINT	{$$ = new safedint_type_name_c(locloc(@$));}
+| SAFELINT	{$$ = new safelint_type_name_c(locloc(@$));}
 ;
 unsigned_integer_type_name:
-USINT	{$$ = new usint_type_name_c(locloc(@$));}
+USINT		{$$ = new usint_type_name_c(locloc(@$));}
-| UINT	{$$ = new uint_type_name_c(locloc(@$));}
+| UINT		{$$ = new uint_type_name_c(locloc(@$));}
-| UDINT	{$$ = new udint_type_name_c(locloc(@$));}
+| UDINT		{$$ = new udint_type_name_c(locloc(@$));}
-| ULINT	{$$ = new ulint_type_name_c(locloc(@$));}
+| ULINT		{$$ = new ulint_type_name_c(locloc(@$));}
+| SAFEUSINT	{$$ = new safeusint_type_name_c(locloc(@$));}
+| SAFEUINT	{$$ = new safeuint_type_name_c(locloc(@$));}
+| SAFEUDINT	{$$ = new safeudint_type_name_c(locloc(@$));}
+| SAFEULINT	{$$ = new safeulint_type_name_c(locloc(@$));}
 ;
 real_type_name:
-REAL	{$$ = new real_type_name_c(locloc(@$));}
+REAL		{$$ = new real_type_name_c(locloc(@$));}
-| LREAL	{$$ = new lreal_type_name_c(locloc(@$));}
+| LREAL		{$$ = new lreal_type_name_c(locloc(@$));}
+| SAFEREAL	{$$ = new safereal_type_name_c(locloc(@$));}
+| SAFELREAL	{$$ = new safelreal_type_name_c(locloc(@$));}
 ;
 date_type_name:
-DATE		{$$ = new date_type_name_c(locloc(@$));}
+DATE			{$$ = new date_type_name_c(locloc(@$));}
-| TIME_OF_DAY	{$$ = new tod_type_name_c(locloc(@$));}
+| TIME_OF_DAY		{$$ = new tod_type_name_c(locloc(@$));}
-| TOD		{$$ = new tod_type_name_c(locloc(@$));}
+| TOD			{$$ = new tod_type_name_c(locloc(@$));}
-| DATE_AND_TIME	{$$ = new dt_type_name_c(locloc(@$));}
+| DATE_AND_TIME		{$$ = new dt_type_name_c(locloc(@$));}
-| DT		{$$ = new dt_type_name_c(locloc(@$));}
+| DT			{$$ = new dt_type_name_c(locloc(@$));}
+| SAFEDATE		{$$ = new safedate_type_name_c(locloc(@$));}
+| SAFETIME_OF_DAY	{$$ = new safetod_type_name_c(locloc(@$));}
+| SAFETOD		{$$ = new safetod_type_name_c(locloc(@$));}
+| SAFEDATE_AND_TIME	{$$ = new safedt_type_name_c(locloc(@$));}
+| SAFEDT		{$$ = new safedt_type_name_c(locloc(@$));}
 ;
 bit_string_type_name:
-BYTE	{$$ = new byte_type_name_c(locloc(@$));}
+BYTE		{$$ = new byte_type_name_c(locloc(@$));}
-| WORD	{$$ = new word_type_name_c(locloc(@$));}
+| WORD		{$$ = new word_type_name_c(locloc(@$));}
-| DWORD	{$$ = new dword_type_name_c(locloc(@$));}
+| DWORD		{$$ = new dword_type_name_c(locloc(@$));}
-| LWORD	{$$ = new lword_type_name_c(locloc(@$));}
+| LWORD		{$$ = new lword_type_name_c(locloc(@$));}
+| SAFEBYTE	{$$ = new safebyte_type_name_c(locloc(@$));}
+| SAFEWORD	{$$ = new safeword_type_name_c(locloc(@$));}
+| SAFEDWORD	{$$ = new safedword_type_name_c(locloc(@$));}
+| SAFELWORD	{$$ = new safelword_type_name_c(locloc(@$));}
 /* NOTE: see note under the B 1.2.1 section of token
 * and grouping type definition for reason why the BOOL
 * was omitted from this definition.
 */
 ;
 * possible future changes easier to edit...
 */
 elementary_string_type_name:
 STRING	{$$ = new string_type_name_c(locloc(@$));}
 | WSTRING	{$$ = new wstring_type_name_c(locloc(@$));}
+| SAFESTRING	{$$ = new safestring_type_name_c(locloc(@$));}
+| SAFEWSTRING	{$$ = new safewstring_type_name_c(locloc(@$));}
 ;
 /********************************/
 /* ERROR_CHECK_END */
 ;
 il_param_instruction:
 il_param_assignment ',' eol_list
 | il_param_out_assignment ',' eol_list
 /* ERROR_CHECK_BEGIN */
 | il_param_assignment ',' error
 {$$ = NULL; print_err_msg(locl(@2), locf(@3), "EOL missing at the end of parameter assignment in parameter assignment list."); yyerrok;}
 | il_param_out_assignment ',' error
 il_assign_out_operator:
 /*  variable_name SENDTO */
 /*  any_identifier SENDTO */
 sendto_identifier SENDTO
 	{$$ = new il_assign_out_operator_c(NULL, $1, locloc(@$));}
+/* The following is not required, as the sendto_identifier_token returned by flex will
+* also include the 'ENO' identifier.
+* The resulting abstract syntax tree is identical with or without this following rule,
+* as both the eno_identifier and the sendto_identifier are stored as
+* an identifier_c !!
+*/
+/*
 | eno_identifier SENDTO
 	{$$ = new il_assign_out_operator_c(NULL, $1, locloc(@$));}
+*/
 /*| NOT variable_name SENDTO */
 | NOT sendto_identifier SENDTO
 	{$$ = new il_assign_out_operator_c(new not_paramassign_c(locloc(@1)), $2, locloc(@$));}
+/* The following is not required, as the sendto_identifier_token returned by flex will
+* also include the 'ENO' identifier.
+* The resulting abstract syntax tree is identical with or without this following rule,
+* as both the eno_identifier and the sendto_identifier are stored as
+* an identifier_c !!
+*
+* NOTE: Removing the following rule also removes a shift/reduce conflict from the parser.
+*       This conflict is not really an error/ambiguity in the syntax, but rather
+*       due to the fact that more than a single look-ahead token would be required
+*       to correctly parse the syntax, something that bison does not support.
+*
+*       The shift/reduce conflict arises because bison does not know whether
+*       to parse the 'NOT ENO' in the following code
+*         LD 1
+*         funct_name (
+*                      NOT ENO => bool_var,
+*                      EN := TRUE
+*                    )
+*        as either a il_param_assignment (wrong!) or an il_param_out_assignment.(correct).
+*        The '=>' delimiter (known as SEND_TO in this iec.y file) is a dead giveaway that
+*        it should be parsed as an il_param_out_assignment, but still, bison gets confused!
+*        Bison considers the possibility of reducing the 'NOT ENO' as an NOT_operator with
+*        the 'ENO' operand
+*        (NOT_operator -> il_simple_operator -> il_simple_operation -> il_simple_instruction ->
+*          -> simple_instr_list -> il_param_assignment)
+*        instead of reducing it to an il_param_out_operator.
+*        ( il_param_out_operator -> il_param_out_assignment)
+*
+*        Note that the shift/reduce conflict only manifests itself in the il_formal_funct_call,
+*        where both the il_param_out_assignment and il_param_assignment are used!
+*
+*          il_param_out_assignment --+--> il_param_instruction -> il_param_instruction_list --+
+*                                    |                                                        |
+*          il_param_assignment     --+                                                        |
+*                                                                                             |
+*                                                     il_formal_funct_call <- il_param_list <-+
+*
+*/
+/*
 | NOT eno_identifier SENDTO
 	{$$ = new il_assign_out_operator_c(new not_paramassign_c(locloc(@1)), $2, locloc(@$));}
+*/
 /* ERROR_CHECK_BEGIN */
 | error SENDTO
 {$$ = NULL; print_err_msg(locf(@1), locl(@1), "invalid parameter defined in parameter out assignment."); yyerrok;}
 | NOT SENDTO
 {$$ = NULL; print_err_msg(locl(@1), locf(@2), "no parameter defined in parameter out assignment."); yynerrs++;}
 /* ERROR_CHECK_END */
 ;
 unary_expression:
-primary_expression
+non_negative_primary_expression
-| '-' primary_expression
+| '-' non_negative_primary_expression
 	{$$ = new neg_expression_c($2, locloc(@$));}
 | NOT primary_expression
 	{$$ = new not_expression_c($2, locloc(@$));}
 /* ERROR_CHECK_BEGIN */
 | '-' error
 *       (i.e. the constant 9 negative)
 *       OR
 *       expression<-unary_expression<-constant<-integer
 *       (i.e. the constant 9, preceded by a unary negation)
 *
-*       To remove the conlfict, we only allow constants without
+*       To remove the conflict, we only allow constants without
 *       a preceding '-' to be used in primary_expression
+*       (i.e. as a parameter to the unary negation operator)
 */
 /* NOTE: We use enumerated_value_without_identifier instead of enumerated_value
 *       in order to remove a reduce/reduce conflict between reducing an
 *       identifier to a variable or an enumerated_value.
 *
 *       imply (by introducing syntax that allows to unambiguosly reference an
 *       enumerated value - enum_type#enum_value) that in case the same identifier is used
 *       for a variable and an enumerated value, then the variable shall be
 *       considered.
 */
-primary_expression:
+non_negative_primary_expression:
-/* constant */
 non_negative_constant
 //| enumerated_value_without_identifier
 | enumerated_value
 | variable
 | '(' expression ')'
 /* ERROR_CHECK_BEGIN */
 | '(' expression error
 {$$ = NULL; print_err_msg(locl(@2), locf(@3), "')' missing at the end of expression in ST expression."); yyerrok;}
 /* ERROR_CHECK_END */
 ;
+primary_expression:
+constant
+//| enumerated_value_without_identifier
+enumerated_value
+| variable
+| '(' expression ')'
+	{$$ = $2;}
+|  function_invocation
+/* ERROR_CHECK_BEGIN */
+| '(' expression error
+{$$ = NULL; print_err_msg(locl(@2), locf(@3), "')' missing at the end of expression in ST expression."); yyerrok;}
+/* ERROR_CHECK_END */
+;
 /* intermediate helper symbol for primary_expression */
 /* NOTE: function_name includes the standard function name 'NOT' !
 *       This introduces a reduce/reduce conflict, as NOT(var)
 	{$$ = new input_variable_param_assignment_c($1, $3, locloc(@$));}
 /*| variable_name SENDTO variable */
 /*| any_identifier SENDTO variable */
 | sendto_identifier SENDTO variable
 	{$$ = new output_variable_param_assignment_c(NULL, $1, $3, locloc(@$));}
+/* The following is not required, as the sendto_identifier_token returned by flex will
+* also include the 'ENO' identifier.
+* The resulting abstract syntax tree is identical with or without this following rule,
+* as both the eno_identifier and the sendto_identifier are stored as
+* an identifier_c !!
+*/
+/*
 | eno_identifier SENDTO variable
 	{$$ = new output_variable_param_assignment_c(NULL, $1, $3, locloc(@$));}
+*/
 /*| NOT variable_name SENDTO variable */
 /*| NOT any_identifier SENDTO variable*/
 | NOT sendto_identifier SENDTO variable
 	{$$ = new output_variable_param_assignment_c(new not_paramassign_c(locloc(@$)), $2, $4, locloc(@$));}
+/* The following is not required, as the sendto_identifier_token returned by flex will
+* also include the 'ENO' identifier.
+* The resulting abstract syntax tree is identical with or without this following rule,
+* as both the eno_identifier and the sendto_identifier are stored as
+* an identifier_c !!
+*/
+/*
 | NOT eno_identifier SENDTO variable
 	{$$ = new output_variable_param_assignment_c(new not_paramassign_c(locloc(@$)), $2, $4, locloc(@$));}
+*/
 /* ERROR_CHECK_BEGIN */
 | any_identifier ASSIGN error
 {$$ = NULL;
 	 if (is_current_syntax_token()) {print_err_msg(locl(@2), locf(@3), "no expression defined in ST formal parameter assignment.");}
 	 else {print_err_msg(locf(@3), locl(@3), "invalid expression in ST formal parameter assignment."); yyclearin;}
 {$$ = NULL;
 	 if (is_current_syntax_token()) {print_err_msg(locl(@2), locf(@3), "no expression defined in ST formal parameter out assignment.");}
 	 else {print_err_msg(locf(@3), locl(@3), "invalid expression in ST formal parameter out assignment."); yyclearin;}
 	 yyerrok;
 	}
+/*
 | eno_identifier SENDTO error
 {$$ = NULL;
 	 if (is_current_syntax_token()) {print_err_msg(locl(@2), locf(@3), "no expression defined in ST formal parameter out assignment.");}
 	 else {print_err_msg(locf(@3), locl(@3), "invalid expression in ST formal parameter out assignment."); yyclearin;}
 	 yyerrok;
 	}
+*/
 | NOT SENDTO variable
 {$$ = NULL; print_err_msg(locl(@1), locf(@2), "no parameter name defined in ST formal parameter out negated assignment."); yynerrs++;}
 | NOT error SENDTO variable
 {$$ = NULL; print_err_msg(locf(@2), locl(@2), "invalid parameter name defined in ST formal parameter out negated assignment."); yyerrok;}
 | NOT sendto_identifier SENDTO error
 {$$ = NULL;
 	 if (is_current_syntax_token()) {print_err_msg(locl(@3), locf(@4), "no expression defined in ST formal parameter out negated assignment.");}
 	 else {print_err_msg(locf(@4), locl(@4), "invalid expression in ST formal parameter out negated assignment."); yyclearin;}
 	 yyerrok;
 	}
+/*
 | NOT eno_identifier SENDTO error
 {$$ = NULL;
 	 if (is_current_syntax_token()) {print_err_msg(locl(@3), locf(@4), "no expression defined in ST formal parameter out negated assignment.");}
 	 else {print_err_msg(locf(@4), locl(@4), "invalid expression in ST formal parameter out negated assignment."); yyclearin;}
 	 yyerrok;
 	}
+*/
 /* ERROR_CHECK_END */
 ;
 fclose(in_file);
 return -1;
 }
 /* first parse the standard library file... */
+/*
+#if YYDEBUG
+yydebug = 1;
+#endif
+*/
 yyin = lib_file;
 allow_function_overloading = true;
 full_token_loc = full_token_loc_;
 current_filename = libfilename;
 current_tracking = GetNewTracking(yyin);
 for(int i = 0; standard_function_block_names[i] != NULL; i++)
 if (library_element_symtable.find_value(standard_function_block_names[i]) ==
 library_element_symtable.end_value())
 library_element_symtable.insert(standard_function_block_names[i], standard_function_block_name_token);
-#if YYDEBUG
-yydebug = 1;
-#endif
 /* now parse the input file... */
+#if YYDEBUG
+yydebug = 1;
+#endif
 yyin = in_file;
 allow_function_overloading = false;
 full_token_loc = full_token_loc_;
 current_filename = filename;
 current_tracking = GetNewTracking(yyin);

changeset 257	90782e241346
parent 202	da1a8186f86f
child 258	d7d92b2f87e9