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expressp.c
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expressp.c
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/* ------------------------------------------------------------------------- */
/* "expressp" : The expression parser */
/* */
/* Part of Inform 6.33 */
/* copyright (c) Graham Nelson 1993 - 2013 */
/* */
/* ------------------------------------------------------------------------- */
#include "header.h"
/* --- Interface to lexer -------------------------------------------------- */
static char separators_to_operators[103];
static char conditionals_to_operators[7];
static char token_type_allowable[301];
#define NOT_AN_OPERATOR (char) 0x7e
static void make_lexical_interface_tables(void)
{ int i;
for (i=0;i<103;i++)
separators_to_operators[i] = NOT_AN_OPERATOR;
for (i=0;i<NUM_OPERATORS;i++)
if (operators[i].token_type == SEP_TT)
separators_to_operators[operators[i].token_value] = i;
for (i=0;i<7;i++) /* 7 being the size of keyword_group "conditions" */
conditionals_to_operators[i] = NOT_AN_OPERATOR;
for (i=0;i<NUM_OPERATORS;i++)
if (operators[i].token_type == CND_TT)
conditionals_to_operators[operators[i].token_value] = i;
for (i=0;i<301;i++) token_type_allowable[i] = 0;
token_type_allowable[VARIABLE_TT] = 1;
token_type_allowable[SYSFUN_TT] = 1;
token_type_allowable[DQ_TT] = 1;
token_type_allowable[DICTWORD_TT] = 1;
token_type_allowable[SUBOPEN_TT] = 1;
token_type_allowable[SUBCLOSE_TT] = 1;
token_type_allowable[SMALL_NUMBER_TT] = 1;
token_type_allowable[LARGE_NUMBER_TT] = 1;
token_type_allowable[ACTION_TT] = 1;
token_type_allowable[SYSTEM_CONSTANT_TT] = 1;
token_type_allowable[OP_TT] = 1;
}
static token_data current_token, previous_token, heldback_token;
static int comma_allowed, arrow_allowed, superclass_allowed,
bare_prop_allowed,
array_init_ambiguity, action_ambiguity,
etoken_count, inserting_token, bracket_level;
extern int *variable_usage;
int system_function_usage[32];
static int get_next_etoken(void)
{ int v, symbol, mark_symbol_as_used = FALSE,
initial_bracket_level = bracket_level;
etoken_count++;
if (inserting_token)
{ current_token = heldback_token;
inserting_token = FALSE;
}
else
{ get_next_token();
current_token.text = token_text;
current_token.value = token_value;
current_token.type = token_type;
current_token.marker = 0;
current_token.symtype = 0;
current_token.symflags = -1;
}
switch(current_token.type)
{ case LOCAL_VARIABLE_TT:
current_token.type = VARIABLE_TT;
variable_usage[current_token.value] = TRUE;
break;
case DQ_TT:
current_token.marker = STRING_MV;
break;
case SQ_TT:
{ int32 unicode = text_to_unicode(token_text);
if (token_text[textual_form_length] == 0)
{
if (!glulx_mode) {
current_token.value = unicode_to_zscii(unicode);
if (current_token.value == 5)
{ unicode_char_error("Character can be printed \
but not used as a value:", unicode);
current_token.value = '?';
}
if (current_token.value >= 0x100)
current_token.type = LARGE_NUMBER_TT;
else current_token.type = SMALL_NUMBER_TT;
}
else {
current_token.value = unicode;
if (current_token.value >= 0x8000
|| current_token.value < -0x8000)
current_token.type = LARGE_NUMBER_TT;
else current_token.type = SMALL_NUMBER_TT;
}
}
else
{ current_token.type = DICTWORD_TT;
current_token.marker = DWORD_MV;
}
}
break;
case SYMBOL_TT:
ReceiveSymbol:
symbol = current_token.value;
mark_symbol_as_used = TRUE;
v = svals[symbol];
current_token.symtype = stypes[symbol];
current_token.symflags = sflags[symbol];
switch(stypes[symbol])
{ case ROUTINE_T:
current_token.marker = IROUTINE_MV;
break;
case GLOBAL_VARIABLE_T:
current_token.marker = VARIABLE_MV;
break;
case OBJECT_T:
case CLASS_T:
/* All objects must be backpatched in Glulx. */
if (module_switch || glulx_mode)
current_token.marker = OBJECT_MV;
break;
case ARRAY_T:
current_token.marker = ARRAY_MV;
break;
case INDIVIDUAL_PROPERTY_T:
if (module_switch) current_token.marker = IDENT_MV;
break;
case CONSTANT_T:
if (sflags[symbol] & (UNKNOWN_SFLAG + CHANGE_SFLAG))
{ current_token.marker = SYMBOL_MV;
if (module_switch) import_symbol(symbol);
v = symbol;
}
else current_token.marker = 0;
break;
case LABEL_T:
error_named("Label name used as value:", token_text);
break;
default:
current_token.marker = 0;
break;
}
if (sflags[symbol] & SYSTEM_SFLAG)
current_token.marker = 0;
current_token.value = v;
if (!glulx_mode) {
if (((current_token.marker != 0)
&& (current_token.marker != VARIABLE_MV))
|| (v < 0) || (v > 255))
current_token.type = LARGE_NUMBER_TT;
else current_token.type = SMALL_NUMBER_TT;
}
else {
if (((current_token.marker != 0)
&& (current_token.marker != VARIABLE_MV))
|| (v < -0x8000) || (v >= 0x8000))
current_token.type = LARGE_NUMBER_TT;
else current_token.type = SMALL_NUMBER_TT;
}
if (stypes[symbol] == GLOBAL_VARIABLE_T)
{ current_token.type = VARIABLE_TT;
variable_usage[current_token.value] = TRUE;
}
break;
case NUMBER_TT:
if (!glulx_mode) {
if (current_token.value >= 256)
current_token.type = LARGE_NUMBER_TT;
else
current_token.type = SMALL_NUMBER_TT;
}
else {
if (current_token.value < -0x8000
|| current_token.value >= 0x8000)
current_token.type = LARGE_NUMBER_TT;
else
current_token.type = SMALL_NUMBER_TT;
}
break;
case SEP_TT:
switch(current_token.value)
{ case ARROW_SEP:
if (!arrow_allowed)
current_token.type = ENDEXP_TT;
break;
case COMMA_SEP:
if ((bracket_level==0) && (!comma_allowed))
current_token.type = ENDEXP_TT;
break;
case SUPERCLASS_SEP:
if ((bracket_level==0) && (!superclass_allowed))
current_token.type = ENDEXP_TT;
break;
case GREATER_SEP:
get_next_token();
if ((token_type == SEP_TT)
&&((token_value == SEMICOLON_SEP)
|| (token_value == GREATER_SEP)))
current_token.type = ENDEXP_TT;
put_token_back();
break;
case OPENB_SEP:
bracket_level++;
if (expr_trace_level>=3)
{ printf("Previous token type = %d\n",previous_token.type);
printf("Previous token val = %d\n",previous_token.value);
}
if ((previous_token.type == OP_TT)
|| (previous_token.type == SUBOPEN_TT)
|| (previous_token.type == ENDEXP_TT)
|| (array_init_ambiguity)
|| ((bracket_level == 1) && (action_ambiguity)))
current_token.type = SUBOPEN_TT;
else
{ inserting_token = TRUE;
heldback_token = current_token;
current_token.text = "<call>";
bracket_level--;
}
break;
case CLOSEB_SEP:
bracket_level--;
if (bracket_level < 0)
current_token.type = ENDEXP_TT;
else current_token.type = SUBCLOSE_TT;
break;
case SEMICOLON_SEP:
current_token.type = ENDEXP_TT; break;
case MINUS_SEP:
if ((previous_token.type == OP_TT)
|| (previous_token.type == SUBOPEN_TT)
|| (previous_token.type == ENDEXP_TT))
current_token.value = UNARY_MINUS_SEP; break;
case INC_SEP:
if ((previous_token.type == VARIABLE_TT)
|| (previous_token.type == SUBCLOSE_TT)
|| (previous_token.type == LARGE_NUMBER_TT)
|| (previous_token.type == SMALL_NUMBER_TT))
current_token.value = POST_INC_SEP; break;
case DEC_SEP:
if ((previous_token.type == VARIABLE_TT)
|| (previous_token.type == SUBCLOSE_TT)
|| (previous_token.type == LARGE_NUMBER_TT)
|| (previous_token.type == SMALL_NUMBER_TT))
current_token.value = POST_DEC_SEP; break;
case HASHHASH_SEP:
token_text = current_token.text + 2;
ActionUsedAsConstant:
current_token.type = ACTION_TT;
current_token.text = token_text;
current_token.value = 0;
current_token.marker = ACTION_MV;
break;
case HASHADOLLAR_SEP:
obsolete_warning("'#a$Act' is now superseded by '##Act'");
token_text = current_token.text + 3;
goto ActionUsedAsConstant;
case HASHGDOLLAR_SEP:
/* This form generates the position of a global variable
in the global variables array. So Glob is the same as
#globals_array --> #g$Glob */
current_token.text += 3;
current_token.type = SYMBOL_TT;
symbol = symbol_index(current_token.text, -1);
if (stypes[symbol] != GLOBAL_VARIABLE_T) {
ebf_error(
"global variable name after '#g$'",
current_token.text);
current_token.value = 0;
current_token.type = SMALL_NUMBER_TT;
current_token.marker = 0;
break;
}
mark_symbol_as_used = TRUE;
current_token.value = svals[symbol] - MAX_LOCAL_VARIABLES;
current_token.marker = 0;
if (!glulx_mode) {
if (current_token.value >= 0x100)
current_token.type = LARGE_NUMBER_TT;
else current_token.type = SMALL_NUMBER_TT;
}
else {
if (current_token.value >= 0x8000
|| current_token.value < -0x8000)
current_token.type = LARGE_NUMBER_TT;
else current_token.type = SMALL_NUMBER_TT;
}
break;
case HASHNDOLLAR_SEP:
/* This form is still needed for constants like #n$a (the
dictionary address of the word "a"), since 'a' means
the ASCII value of 'a' */
if (strlen(token_text) > 4)
obsolete_warning(
"'#n$word' is now superseded by ''word''");
current_token.type = DICTWORD_TT;
current_token.value = 0;
current_token.text = token_text + 3;
current_token.marker = DWORD_MV;
break;
case HASHRDOLLAR_SEP:
/* This form -- #r$Routinename, to return the routine's */
/* packed address -- is needed far less often in Inform 6, */
/* where just giving the name Routine returns the packed */
/* address. But it's used in a lot of Inform 5 code. */
obsolete_warning(
"'#r$Routine' can now be written just 'Routine'");
current_token.text += 3;
current_token.type = SYMBOL_TT;
current_token.value = symbol_index(current_token.text, -1);
goto ReceiveSymbol;
case HASHWDOLLAR_SEP:
error("The obsolete '#w$word' construct has been removed");
break;
case HASH_SEP:
system_constants.enabled = TRUE;
get_next_token();
system_constants.enabled = FALSE;
if (token_type != SYSTEM_CONSTANT_TT)
{ ebf_error(
"'r$', 'n$', 'g$' or internal Inform constant name after '#'",
token_text);
break;
}
else
{ current_token.type = token_type;
current_token.value = token_value;
current_token.text = token_text;
current_token.marker = INCON_MV;
}
break;
}
break;
case CND_TT:
v = conditionals_to_operators[current_token.value];
if (v != NOT_AN_OPERATOR)
{ current_token.type = OP_TT; current_token.value = v;
}
break;
}
if (current_token.type == SEP_TT)
{ v = separators_to_operators[current_token.value];
if (v != NOT_AN_OPERATOR)
{ if ((veneer_mode)
|| ((v!=MESSAGE_OP) && (v!=MPROP_NUM_OP) && (v!=MPROP_NUM_OP)))
{ current_token.type = OP_TT; current_token.value = v;
if (array_init_ambiguity &&
((v==MINUS_OP) || (v==UNARY_MINUS_OP)) &&
(initial_bracket_level == 0) &&
(etoken_count != 1))
warning("Without bracketing, the minus sign '-' is ambiguous");
}
}
}
/* A feature of Inform making it annoyingly hard to parse left-to-right
is that there is no clear delimiter for expressions; that is, the
legal syntax often includes sequences of expressions with no
intervening markers such as commas. We therefore need to use some
internal context to determine whether an end is in sight... */
if (token_type_allowable[current_token.type]==0)
{ if (expr_trace_level >= 3)
{ printf("Discarding as not allowable: '%s' ", current_token.text);
describe_token(current_token);
printf("\n");
}
current_token.type = ENDEXP_TT;
}
else
if ((!((initial_bracket_level > 0)
|| (previous_token.type == ENDEXP_TT)
|| ((previous_token.type == OP_TT)
&& (operators[previous_token.value].usage != POST_U))
|| (previous_token.type == SYSFUN_TT)))
&& ((current_token.type != OP_TT)
|| (operators[current_token.value].usage == PRE_U)))
{ if (expr_trace_level >= 3)
{ printf("Discarding as no longer part: '%s' ", current_token.text);
describe_token(current_token);
printf("\n");
}
current_token.type = ENDEXP_TT;
}
else
{ if (mark_symbol_as_used) sflags[symbol] |= USED_SFLAG;
if (expr_trace_level >= 3)
{ printf("Expr token = '%s' ", current_token.text);
describe_token(current_token);
printf("\n");
}
}
if ((previous_token.type == ENDEXP_TT)
&& (current_token.type == ENDEXP_TT)) return FALSE;
previous_token = current_token;
return TRUE;
}
/* --- Operator precedences ------------------------------------------------ */
#define LOWER_P 101
#define EQUAL_P 102
#define GREATER_P 103
#define e1 1 /* Missing operand error */
#define e2 2 /* Unexpected close bracket */
#define e3 3 /* Missing operator error */
#define e4 4 /* Expression ends with an open bracket */
#define e5 5 /* Associativity illegal error */
const int prec_table[] = {
/* a .......... ( ) end op term */
/* b ( */ LOWER_P, e3, LOWER_P, LOWER_P, e3,
/* . ) */ EQUAL_P, GREATER_P, e2, GREATER_P, GREATER_P,
/* . end */ e4, GREATER_P, e1, GREATER_P, GREATER_P,
/* . op */ LOWER_P, GREATER_P, LOWER_P, -1, GREATER_P,
/* . term */ LOWER_P, e3, LOWER_P, LOWER_P, e3
};
static int find_prec(token_data a, token_data b)
{
/* We are comparing the precedence of tokens a and b
(where a occurs to the left of b). If the expression is correct,
the only possible values are GREATER_P, LOWER_P or EQUAL_P;
if it is malformed then one of e1 to e5 results.
Note that this routine is not symmetrical and that the relation
is not trichotomous.
If a and b are equal (and aren't brackets), then
a LOWER_P a if a right-associative
a GREATER_P a if a left-associative
*/
int i, j, l1, l2;
switch(a.type)
{ case SUBOPEN_TT: i=0; break;
case SUBCLOSE_TT: i=1; break;
case ENDEXP_TT: i=2; break;
case OP_TT: i=3; break;
default: i=4; break;
}
switch(b.type)
{ case SUBOPEN_TT: i+=0; break;
case SUBCLOSE_TT: i+=5; break;
case ENDEXP_TT: i+=10; break;
case OP_TT: i+=15; break;
default: i+=20; break;
}
j = prec_table[i]; if (j != -1) return j;
l1 = operators[a.value].precedence;
l2 = operators[b.value].precedence;
if (operators[b.value].usage == PRE_U) return LOWER_P;
if (operators[a.value].usage == POST_U) return GREATER_P;
/* Anomalous rule to resolve the function call precedence, which is
different on the right from on the left, e.g., in:
alpha.beta(gamma)
beta(gamma).alpha
*/
if ((l1 == 11) && (l2 > 11)) return GREATER_P;
if (l1 < l2) return LOWER_P;
if (l1 > l2) return GREATER_P;
switch(operators[a.value].associativity)
{ case L_A: return GREATER_P;
case R_A: return LOWER_P;
case 0: return e5;
}
return GREATER_P;
}
/* --- Converting token to operand ----------------------------------------- */
/* Must match the switch statement below */
int z_system_constant_list[] =
{ adjectives_table_SC,
actions_table_SC,
classes_table_SC,
identifiers_table_SC,
preactions_table_SC,
largest_object_SC,
strings_offset_SC,
code_offset_SC,
actual_largest_object_SC,
static_memory_offset_SC,
array_names_offset_SC,
readable_memory_offset_SC,
cpv__start_SC,
cpv__end_SC,
ipv__start_SC,
ipv__end_SC,
array__start_SC,
array__end_SC,
highest_attribute_number_SC,
attribute_names_array_SC,
highest_property_number_SC,
property_names_array_SC,
highest_action_number_SC,
action_names_array_SC,
highest_fake_action_number_SC,
fake_action_names_array_SC,
highest_routine_number_SC,
routine_names_array_SC,
routines_array_SC,
routine_flags_array_SC,
highest_global_number_SC,
global_names_array_SC,
globals_array_SC,
global_flags_array_SC,
highest_array_number_SC,
array_names_array_SC,
array_flags_array_SC,
highest_constant_number_SC,
constant_names_array_SC,
highest_class_number_SC,
class_objects_array_SC,
highest_object_number_SC,
-1 };
static int32 value_of_system_constant_z(int t)
{ switch(t)
{ case adjectives_table_SC:
return adjectives_offset;
case actions_table_SC:
return actions_offset;
case classes_table_SC:
return class_numbers_offset;
case identifiers_table_SC:
return identifier_names_offset;
case preactions_table_SC:
return preactions_offset;
case largest_object_SC:
return 256 + no_objects - 1;
case strings_offset_SC:
return strings_offset/scale_factor;
case code_offset_SC:
return code_offset/scale_factor;
case actual_largest_object_SC:
return no_objects;
case static_memory_offset_SC:
return static_memory_offset;
case array_names_offset_SC:
return array_names_offset;
case readable_memory_offset_SC:
return Write_Code_At;
case cpv__start_SC:
return prop_values_offset;
case cpv__end_SC:
return class_numbers_offset;
case ipv__start_SC:
return individuals_offset;
case ipv__end_SC:
return variables_offset;
case array__start_SC:
return variables_offset + (MAX_GLOBAL_VARIABLES*WORDSIZE);
case array__end_SC:
return static_memory_offset;
case highest_attribute_number_SC:
return no_attributes-1;
case attribute_names_array_SC:
return attribute_names_offset;
case highest_property_number_SC:
return no_individual_properties-1;
case property_names_array_SC:
return identifier_names_offset + 2;
case highest_action_number_SC:
return no_actions-1;
case action_names_array_SC:
return action_names_offset;
case highest_fake_action_number_SC:
return ((grammar_version_number==1)?256:4096) + no_fake_actions-1;
case fake_action_names_array_SC:
return fake_action_names_offset;
case highest_routine_number_SC:
return no_named_routines-1;
case routine_names_array_SC:
return routine_names_offset;
case routines_array_SC:
return routines_array_offset;
case routine_flags_array_SC:
return routine_flags_array_offset;
case highest_global_number_SC:
return 16 + no_globals-1;
case global_names_array_SC:
return global_names_offset;
case globals_array_SC:
return variables_offset;
case global_flags_array_SC:
return global_flags_array_offset;
case highest_array_number_SC:
return no_arrays-1;
case array_names_array_SC:
return array_names_offset;
case array_flags_array_SC:
return array_flags_array_offset;
case highest_constant_number_SC:
return no_named_constants-1;
case constant_names_array_SC:
return constant_names_offset;
case highest_class_number_SC:
return no_classes-1;
case class_objects_array_SC:
return class_numbers_offset;
case highest_object_number_SC:
return no_objects-1;
}
error_named("System constant not implemented in Z-code",
system_constants.keywords[t]);
return(0);
}
/* Must match the switch statement below */
int glulx_system_constant_list[] =
{ classes_table_SC,
identifiers_table_SC,
array_names_offset_SC,
cpv__start_SC,
cpv__end_SC,
dictionary_table_SC,
dynam_string_table_SC,
grammar_table_SC,
actions_table_SC,
globals_array_SC,
-1 };
static int32 value_of_system_constant_g(int t)
{
switch (t) {
case classes_table_SC:
return Write_RAM_At + class_numbers_offset;
case identifiers_table_SC:
return Write_RAM_At + identifier_names_offset;
case array_names_offset_SC:
return Write_RAM_At + array_names_offset;
case cpv__start_SC:
return prop_defaults_offset;
case cpv__end_SC:
return Write_RAM_At + class_numbers_offset;
case dictionary_table_SC:
return dictionary_offset;
case dynam_string_table_SC:
return abbreviations_offset;
case grammar_table_SC:
return grammar_table_offset;
case actions_table_SC:
return actions_offset;
case globals_array_SC:
return variables_offset;
}
error_named("System constant not implemented in Glulx",
system_constants.keywords[t]);
return 0;
}
extern int32 value_of_system_constant(int t)
{
if (!glulx_mode)
return value_of_system_constant_z(t);
else
return value_of_system_constant_g(t);
}
static int evaluate_term(token_data t, assembly_operand *o)
{
/* If the given token is a constant, evaluate it into the operand.
For now, the identifiers are considered variables.
Returns FALSE if it fails to understand type. */
int32 v;
o->marker = t.marker;
o->symtype = t.symtype;
o->symflags = t.symflags;
switch(t.type)
{ case LARGE_NUMBER_TT:
v = t.value;
if (!glulx_mode) {
if (v < 0) v = v + 0x10000;
o->type = LONG_CONSTANT_OT;
o->value = v;
}
else {
o->value = v;
o->type = CONSTANT_OT;
}
return(TRUE);
case SMALL_NUMBER_TT:
v = t.value;
if (!glulx_mode) {
if (v < 0) v = v + 0x10000;
o->type = SHORT_CONSTANT_OT;
o->value = v;
}
else {
o->value = v;
set_constant_ot(o);
}
return(TRUE);
case DICTWORD_TT:
/* Find the dictionary address, adding to dictionary if absent */
if (!glulx_mode)
o->type = LONG_CONSTANT_OT;
else
o->type = CONSTANT_OT;
o->value = dictionary_add(t.text, 0x80, 0, 0);
return(TRUE);
case DQ_TT:
/* Create as a static string */
if (!glulx_mode)
o->type = LONG_CONSTANT_OT;
else
o->type = CONSTANT_OT;
o->value = compile_string(t.text, FALSE, FALSE);
return(TRUE);
case VARIABLE_TT:
if (!glulx_mode) {
o->type = VARIABLE_OT;
}
else {
if (t.value >= MAX_LOCAL_VARIABLES) {
o->type = GLOBALVAR_OT;
}
else {
/* This includes "local variable zero", which is really
the stack-pointer magic variable. */
o->type = LOCALVAR_OT;
}
}
o->value = t.value;
return(TRUE);
case SYSFUN_TT:
if (!glulx_mode) {
o->type = VARIABLE_OT;
o->value = t.value + 256;
}
else {
o->type = SYSFUN_OT;
o->value = t.value;
}
system_function_usage[t.value] = 1;
return(TRUE);
case ACTION_TT:
*o = action_of_name(t.text);
return(TRUE);
case SYSTEM_CONSTANT_TT:
/* Certain system constants depend only on the
version number and need no backpatching, as they
are known in advance. We can therefore evaluate
them immediately. */
if (!glulx_mode) {
o->type = LONG_CONSTANT_OT;
switch(t.value)
{
case version_number_SC:
o->type = SHORT_CONSTANT_OT;
o->marker = 0;
v = version_number; break;
case dict_par1_SC:
o->type = SHORT_CONSTANT_OT;
o->marker = 0;
v = (version_number==3)?4:6; break;
case dict_par2_SC:
o->type = SHORT_CONSTANT_OT;
o->marker = 0;
v = (version_number==3)?5:7; break;
case dict_par3_SC:
o->type = SHORT_CONSTANT_OT;
o->marker = 0;
v = (version_number==3)?6:8; break;
case lowest_attribute_number_SC:
case lowest_action_number_SC:
case lowest_routine_number_SC:
case lowest_array_number_SC:
case lowest_constant_number_SC:
case lowest_class_number_SC:
o->type = SHORT_CONSTANT_OT; o->marker = 0; v = 0; break;
case lowest_object_number_SC:
case lowest_property_number_SC:
o->type = SHORT_CONSTANT_OT; o->marker = 0; v = 1; break;
case lowest_global_number_SC:
o->type = SHORT_CONSTANT_OT; o->marker = 0; v = 16; break;
case lowest_fake_action_number_SC:
o->type = LONG_CONSTANT_OT; o->marker = 0;
v = ((grammar_version_number==1)?256:4096); break;
case oddeven_packing_SC:
o->type = SHORT_CONSTANT_OT; o->marker = 0;
v = oddeven_packing_switch; break;
default:
v = t.value;
o->marker = INCON_MV;
break;
}
o->value = v;
}
else {
o->type = CONSTANT_OT;
switch(t.value)
{
/* The three dict_par flags point at the lower byte
of the flag field, because the library is written
to expect one-byte fields, even though the compiler
generates a dictionary with room for two. */
case dict_par1_SC:
o->type = BYTECONSTANT_OT;
o->marker = 0;
v = DICT_ENTRY_FLAG_POS+1;
break;
case dict_par2_SC:
o->type = BYTECONSTANT_OT;
o->marker = 0;
v = DICT_ENTRY_FLAG_POS+3;
break;
case dict_par3_SC:
o->type = BYTECONSTANT_OT;
o->marker = 0;
v = DICT_ENTRY_FLAG_POS+5;
break;
/* ###fix: need to fill more of these in! */
default:
v = t.value;
o->marker = INCON_MV;
break;
}
o->value = v;
}
return(TRUE);
default:
return(FALSE);
}
}
/* --- Emitter ------------------------------------------------------------- */
expression_tree_node *ET;
static int ET_used;
extern void clear_expression_space(void)
{ ET_used = 0;
}
static assembly_operand *emitter_stack;
static int *emitter_markers;
static int *emitter_bracket_counts;
#define FUNCTION_VALUE_MARKER 1
#define ARGUMENT_VALUE_MARKER 2
#define OR_VALUE_MARKER 3
static int emitter_sp;
static int is_property_t(int symbol_type)
{ return ((symbol_type == PROPERTY_T) || (symbol_type == INDIVIDUAL_PROPERTY_T));
}
static void mark_top_of_emitter_stack(int marker, token_data t)
{ if (emitter_sp < 1)
{ compiler_error("SR error: Attempt to add a marker to the top of an empty emitter stack");
return;
}
if (expr_trace_level >= 2)
{ printf("Marking top of emitter stack (which is ");
print_operand(emitter_stack[emitter_sp-1]);
printf(") as ");
switch(marker)
{
case FUNCTION_VALUE_MARKER:
printf("FUNCTION");
break;
case ARGUMENT_VALUE_MARKER:
printf("ARGUMENT");
break;
case OR_VALUE_MARKER:
printf("OR_VALUE");
break;
default:
printf("UNKNOWN");
break;
}
printf("\n");
}
if (emitter_markers[emitter_sp-1])
{ if (marker == ARGUMENT_VALUE_MARKER)
{
warning("Ignoring spurious leading comma");
return;
}
error_named("Missing operand for", t.text);
if (emitter_sp == MAX_EXPRESSION_NODES)
memoryerror("MAX_EXPRESSION_NODES", MAX_EXPRESSION_NODES);
emitter_markers[emitter_sp] = 0;
emitter_bracket_counts[emitter_sp] = 0;
emitter_stack[emitter_sp] = zero_operand;
emitter_sp++;
}
emitter_markers[emitter_sp-1] = marker;
}
static void add_bracket_layer_to_emitter_stack(int depth)
{ /* There's no point in tracking bracket layers that don't fence off any values. */
if (emitter_sp < depth + 1) return;
if (expr_trace_level >= 2)
printf("Adding bracket layer\n");
++emitter_bracket_counts[emitter_sp-depth-1];
}
static void remove_bracket_layer_from_emitter_stack()
{ /* Bracket layers that don't fence off any values will not have been tracked. */
if (emitter_sp < 2) return;
if (expr_trace_level >= 2)
printf("Removing bracket layer\n");
if (emitter_bracket_counts[emitter_sp-2] <= 0)
{ compiler_error("SR error: Attempt to remove a nonexistent bracket layer from the emitter stack");
return;
}
--emitter_bracket_counts[emitter_sp-2];
}
static void emit_token(token_data t)
{ assembly_operand o1, o2; int arity, stack_size, i;
int op_node_number, operand_node_number, previous_node_number;
int32 x;