some internal cleanup concerning empty expressions

git-svn-id: https://svn.code.sf.net/p/acme-crossass/code-0/trunk@123 4df02467-bbd4-4a76-a152-e7ce94205b78

src/alu.c

@@ -12,7 +12,7 @@
 //		give a warning).
 // 31 May 2014	Added "0b" binary number prefix as alternative to "%".
 // 28 Apr 2015	Added symbol name output to "value not defined" error.
-//  1 Feb 2019	Prepared to make "honor leading zeroes" optionally later on.
+//  1 Feb 2019	Prepared to make "honor leading zeroes" optionally (now done)
 #include "alu.h"
 #include <stdlib.h>
 #include <math.h>	// only for fp support
@@ -778,6 +778,7 @@ static void expect_operand_or_monadic_operator(void)
 			if (operator_stack[operator_sp - 1] == &ops_exprstart) {
 				PUSH_OPERATOR(&ops_exprend);
 				alu_state = STATE_TRY_TO_REDUCE_STACKS;
+				// TODO - return "there was nothing" to get rid of "EXISTS" flag?
 			} else {
 				Throw_error(exception_syntax);
 				alu_state = STATE_ERROR;
@@ -799,6 +800,7 @@ now_expect_dyadic:
 			alu_state = STATE_EXPECT_DYADIC_OPERATOR;
 		break;
 	}
+	// TODO - return "there was something" to get rid of "EXISTS" flag?
 }
 
 
@@ -1508,7 +1510,7 @@ static int parse_expression(struct result *result)
 		// (currently LDA'' results in both "no string given" AND "illegal combination of command and addressing mode"!)
 	}
 	// return number of open (unmatched) parentheses
-	return open_parentheses;
+	return open_parentheses;	// FIXME - move this into "expression struct flags", together with indirect flag and EXISTS flag
 }
 
 
@@ -1528,9 +1530,9 @@ int ALU_optional_defined_int(intval_t *target)	// ACCEPT_EMPTY
 	if (parse_expression(&result))
 		Throw_error(exception_paren_open);
 	// do not combine the next two checks, they were separated because EXISTS should move from result flags to expression flags...
-	if (result.flags & MVALUE_EXISTS)
-		if ((result.flags & MVALUE_DEFINED) == 0)
-			Throw_serious_error(value_not_defined());
+	if ((result.flags & MVALUE_EXISTS)
+	&& ((result.flags & MVALUE_DEFINED) == 0))
+		Throw_serious_error(value_not_defined());
 	if ((result.flags & MVALUE_EXISTS) == 0)
 		return 0;
 
@@ -1616,11 +1618,13 @@ extern void ALU_defined_int(struct result *intresult)	// no ACCEPT constants?
 // This function allows for one '(' too many. Needed when parsing indirect
 // addressing modes where internal indices have to be possible. Returns number
 // of parentheses still open (either 0 or 1).
+// If the result's "exists" flag is clear (=empty expression), it throws an
+// error.
 // OPEN_PARENTHESIS: allow
 // UNDEFINED: allow
-// EMPTY: allow
+// EMPTY: complain
 // FLOAT: convert to int
-int ALU_liberal_int(struct result *intresult)	// ACCEPT_EMPTY | ACCEPT_UNDEFINED | ACCEPT_OPENPARENTHESIS
+int ALU_liberal_int(struct result *intresult)	// ACCEPT_UNDEFINED | ACCEPT_OPENPARENTHESIS
 {
 	int	parentheses_still_open;
 
@@ -1634,6 +1638,8 @@ int ALU_liberal_int(struct result *intresult)	// ACCEPT_EMPTY | ACCEPT_UNDEFINED
 		parentheses_still_open = 0;
 		Throw_error(exception_paren_open);
 	}
+	if ((intresult->flags & MVALUE_EXISTS) == 0)
+		Throw_error(exception_no_value);
 	if ((intresult->flags & MVALUE_EXISTS)
 	&& ((intresult->flags & MVALUE_DEFINED) == 0))
 		result_is_undefined();

src/alu.h

@@ -12,10 +12,10 @@
 
 // constants
 
-// meaning of bits in "flags" of struct result:
-// TODO - this is only for future "number" result type, so move EXISTS and INDIRECT somewhere else (expression flags? make "nothing" its own result type!)
+// TODO - move EXISTS and INDIRECT to a new "expression flags" struct! make "nothing" its own result type?
 #define MVALUE_EXISTS	(1u << 8)	// 0: expression was empty. 1: there was *something* to parse.
 #define MVALUE_INDIRECT	(1u << 7)	// needless parentheses indicate use of indirect addressing modes
+// meaning of bits in "flags" of struct result:
 #define MVALUE_IS_FP	(1u << 6)	// floating point value
 #define MVALUE_UNSURE	(1u << 5)	// value once was related to undefined
 // expression. Needed for producing the same addresses in all passes; because in
@@ -26,8 +26,7 @@
 #define MVALUE_FORCE24	(1u << 2)	// value usage forces 24-bit usage
 #define MVALUE_FORCE16	(1u << 1)	// value usage forces 16-bit usage
 #define MVALUE_FORCE08	(1u << 0)	// value usage forces 8-bit usage
-#define MVALUE_FORCEBITS	(MVALUE_FORCE08|MVALUE_FORCE16|MVALUE_FORCE24)
-//#define MVALUE_GIVEN	(MVALUE_DEFINED | MVALUE_EXISTS)	// bit mask for fixed values (defined and existing)	TODO: remove this
+#define MVALUE_FORCEBITS	(MVALUE_FORCE08 | MVALUE_FORCE16 | MVALUE_FORCE24)
 
 
 // create dynamic buffer, operator/function trees and operator/operand stacks

src/flow.c

@@ -1,5 +1,5 @@
 // ACME - a crossassembler for producing 6502/65c02/65816/65ce02 code.
-// Copyright (C) 1998-2019 Marco Baye
+// Copyright (C) 1998-2020 Marco Baye
 // Have a look at "acme.c" for further info
 //
 // Flow control stuff (loops, conditional assembly etc.)
@@ -55,7 +55,7 @@ void flow_forloop(struct for_loop *loop)
 	// (not yet useable; pointer and line number are still missing)
 	Input_now = &loop_input;
 	// init counter
-	loop_counter.flags = MVALUE_DEFINED | MVALUE_EXISTS;	// TODO - remove EXISTS, it is never checked
+	loop_counter.flags = MVALUE_DEFINED;
 	loop_counter.val.intval = loop->counter.first;
 	loop_counter.addr_refs = loop->counter.addr_refs;
 	symbol_set_value(loop->symbol, &loop_counter, TRUE);

src/mnemo.c

@@ -528,28 +528,28 @@ static int get_argument(struct result *result)
 
 	SKIPSPACE();
 	switch (GotByte) {
+	case CHAR_EOS:
+		address_mode_bits = AMB_IMPLIED;
+		break;
+	case '#':
+		GetByte();	// proceed with next char
+		address_mode_bits = AMB_IMMEDIATE;
+		ALU_int_result(result);
+		typesystem_want_imm(result);	// FIXME - this is wrong for 65ce02's PHW#
+		break;
 	case '[':
 		GetByte();	// proceed with next char
 		ALU_int_result(result);
 		typesystem_want_addr(result);
 		if (GotByte == ']')
-			address_mode_bits |= AMB_LONGINDIRECT | AMB_INDEX(get_index(TRUE));
+			address_mode_bits = AMB_LONGINDIRECT | AMB_INDEX(get_index(TRUE));
 		else
 			Throw_error(exception_syntax);
 		break;
-	case '#':
-		GetByte();	// proceed with next char
-		address_mode_bits |= AMB_IMMEDIATE;
-		ALU_int_result(result);
-		typesystem_want_imm(result);	// FIXME - this is wrong for 65ce02's PHW#
-		break;
 	default:
 		// liberal, to allow for "(...,"
 		open_paren = ALU_liberal_int(result);
 		typesystem_want_addr(result);
-		// check for implied addressing
-		if ((result->flags & MVALUE_EXISTS) == 0)
-			address_mode_bits |= AMB_IMPLIED;
 		// check for indirect addressing
 		if (result->flags & MVALUE_INDIRECT)
 			address_mode_bits |= AMB_INDIRECT;
@@ -568,7 +568,7 @@ static int get_argument(struct result *result)
 	}
 	// ensure end of line
 	Input_ensure_EOS();
-	//printf("AM: %x\n", addressing_mode);
+	//printf("AM: %x\n", address_mode_bits);
 	return address_mode_bits;
 }
 

src/output.c

@@ -1,5 +1,5 @@
 // ACME - a crossassembler for producing 6502/65c02/65816/65ce02 code.
-// Copyright (C) 1998-2019 Marco Baye
+// Copyright (C) 1998-2020 Marco Baye
 // Have a look at "acme.c" for further info
 //
 // Output stuff

src/pseudoopcodes.c

@@ -1,5 +1,5 @@
 // ACME - a crossassembler for producing 6502/65c02/65816/65ce02 code.
-// Copyright (C) 1998-2017 Marco Baye
+// Copyright (C) 1998-2020 Marco Baye
 // Have a look at "acme.c" for further info
 //
 // pseudo opcode stuff

src/symbol.c

@@ -222,7 +222,7 @@ void symbol_define(intval_t value)
 	struct result	result;
 	struct symbol	*symbol;
 
-	result.flags = MVALUE_DEFINED | MVALUE_EXISTS;	// TODO - remove EXISTS, it is never checked
+	result.flags = MVALUE_DEFINED;
 	result.val.intval = value;
 	symbol = symbol_find(SCOPE_GLOBAL, 0);
 	symbol_set_value(symbol, &result, TRUE);

src/version.h

@@ -9,7 +9,7 @@
 
 #define RELEASE		"0.96.5"	// update before release	FIXME
 #define CODENAME	"Fenchurch"	// update before release
-#define CHANGE_DATE	"25 Apr"	// update before release	FIXME
+#define CHANGE_DATE	"26 Apr"	// update before release	FIXME
 #define CHANGE_YEAR	"2020"		// update before release
 //#define HOME_PAGE	"http://home.pages.de/~mac_bacon/smorbrod/acme/"
 #define HOME_PAGE	"http://sourceforge.net/p/acme-crossass/"	// FIXME