/* writestatetables
* Creates and dumps the state tables. Every function with states has a state
* table that contains jump addresses (or overlay indices) the branch to the
* appropriate function using the (hidden) state variable as the criterion.
* Technically, this happens in a "switch" (or an "iswitch") instruction.
* This function also creates the hidden state variables (one for each
* automaton) in the data segment.
*/
SC_FUNC void writestatetables(symbol *root,int lbl_nostate,int lbl_ignorestate)
{
int lbl_default,lbl_table,lbl_defnostate;
int statecount;
symbol *sym;
constvalue *fsa, *state;
statelist *stlist;
int fsa_id,listid;
assert(code_idx>0); /* leader must already have been written */
/* check whether there are any functions that have states */
for (sym=root->next; sym!=NULL; sym=sym->next)
if (sym->ident==iFUNCTN && (sym->usage & (uPUBLIC | uREAD))!=0 && sym->states!=NULL)
break;
if (sym==NULL)
return; /* no function has states, nothing to do next */
assert(pc_ovl0size[ovlNO_STATE][0]>0); /* state exit point must already have been created */
assert(pc_ovl0size[ovlNO_STATE][1]>0);
/* write the "state-selectors" table with all automatons (update the
* automatons structure too, as we are now assigning the address to
* each automaton state-selector variable)
*/
assert(glb_declared==0);
begdseg();
for (fsa=sc_automaton_tab.next; fsa!=NULL; fsa=fsa->next) {
defstorage();
stgwrite("0\t; automaton ");
if (strlen(fsa->name)==0)
stgwrite("(anonymous)");
else
stgwrite(fsa->name);
stgwrite("\n");
fsa->value=glb_declared*sizeof(cell);
glb_declared++;
} /* for */
/* write stubs and jump tables for all state functions */
begcseg();
for (sym=root->next; sym!=NULL; sym=sym->next) {
if (sym->ident==iFUNCTN && (sym->usage & (uPUBLIC | uREAD))!=0 && sym->states!=NULL) {
stlist=sym->states->next;
assert(stlist!=NULL); /* there should be at least one state item */
listid=stlist->id;
assert(listid==-1 || listid>0);
if (listid==-1 && stlist->next!=NULL) {
/* first index is the "fallback", take the next one (if available) */
stlist=stlist->next;
listid=stlist->id;
} /* if */
if (listid==-1) {
/* first index is the fallback, there is no second... */
stlist->label=0; /* insert dummy label number */
/* this is an error, but we postpone adding the error message until the
* function definition
*/
continue;
} /* if */
/* generate label numbers for all statelist ids */
for (stlist=sym->states->next; stlist!=NULL; stlist=stlist->next) {
if (pc_overlays>0) {
/* code overlay indices should already be set, see gen_ovlinfo() */
assert(stlist->label>0);
} else {
assert(stlist->label==0);
stlist->label=getlabel();
} /* if */
} /* for */
if (strcmp(sym->name,uENTRYFUNC)==0)
continue; /* do not generate stubs for this special function */
sym->addr=code_idx; /* fix the function address now */
/* get automaton id for this function */
assert(listid>0);
fsa_id=state_getfsa(listid);
assert(fsa_id>=0); /* automaton 0 exists */
fsa=automaton_findid(fsa_id);
/* count the number of states actually used; at the same time, check
* whether there is a default (i.e. "fallback") state function
*/
statecount=0;
if (strcmp(sym->name,uEXITFUNC)==0) {
lbl_default= (pc_overlays>0) ? ovlEXITSTATE : lbl_ignorestate;
} else {
lbl_defnostate= (pc_overlays>0) ? ovlNO_STATE : lbl_nostate;
lbl_default=lbl_defnostate;
} /* if */
for (stlist=sym->states->next; stlist!=NULL; stlist=stlist->next) {
if (stlist->id==-1) {
lbl_default=stlist->label;
} else {
statecount+=state_count(stlist->id);
} /* if */
} /* for */
/* generate a stub entry for the functions */
stgwrite("\tload.pri ");
outval(fsa->value,TRUE,FALSE);
stgwrite("\t; ");
stgwrite(sym->name);
if (pc_overlays>0) {
/* add overlay index */
stgwrite("/");
outval(sym->index,FALSE,FALSE);
} /* if */
stgwrite("\n");
code_idx+=opcodes(1)+opargs(1); /* calculate code length */
lbl_table=getlabel();
ffswitch(lbl_table,(pc_overlays>0));
/* generate the jump table */
setlabel(lbl_table);
ffcase(statecount,lbl_default,TRUE,(pc_overlays>0));
for (state=sc_state_tab.next; state!=NULL; state=state->next) {
if (state->index==fsa_id) {
/* find the label for this list id */
for (stlist=sym->states->next; stlist!=NULL; stlist=stlist->next) {
if (stlist->id!=-1 && state_inlist(stlist->id,(int)state->value)) {
/* when overlays are used, the jump-label for the case statement
* are overlay indices instead of code labels
*/
ffcase(state->value,stlist->label,FALSE,(pc_overlays>0));
break;
} /* if */
} /* for */
if (stlist==NULL && lbl_default==lbl_defnostate)
error(230,state->name,sym->name); /* unimplemented state, no fallback */
} /* if (state belongs to automaton of function) */
} /* for (state) */
stgwrite("\n");
/* the jump table gets its own overlay index, and the size of the jump
* table must therefore be known (i.e. update the codeaddr field of the
* function with the address where the jump table ends)
*/
sym->codeaddr=code_idx;
} /* if (is function, used & having states) */
} /* for (sym) */
}
/* When a subroutine returns to address 0, the AMX must halt. In earlier
* releases, the RET and RETN opcodes checked for the special case 0 address.
* Today, the compiler simply generates a HALT instruction at address 0. So
* a subroutine can savely return to 0, and then encounter a HALT.
*/
SC_FUNC void writeleader(symbol *root)
{
int lbl_nostate,lbl_table;
int statecount;
symbol *sym;
constvalue *fsa, *state, *stlist;
int fsa_id,listid;
char lbl_default[sNAMEMAX+1];
assert(code_idx==0);
begcseg();
stgwrite(";program exit point\n");
stgwrite("\thalt 0\n\n");
code_idx+=opcodes(1)+opargs(1); /* calculate code length */
/* check whether there are any functions that have states */
for (sym=root->next; sym!=NULL; sym=sym->next)
if (sym->ident==iFUNCTN && (sym->usage & (uPUBLIC | uREAD))!=0 && sym->states!=NULL)
break;
if (sym==NULL)
return; /* no function has states, nothing to do next */
/* generate an error function that is called for an undefined state */
stgwrite("\n;exit point for functions called from the wrong state\n");
lbl_nostate=getlabel();
setlabel(lbl_nostate);
stgwrite("\thalt ");
outval(AMX_ERR_INVSTATE,TRUE);
code_idx+=opcodes(1)+opargs(1); /* calculate code length */
/* write the "state-selectors" table with all automatons (update the
* automatons structure too, as we are now assigning the address to
* each automaton state-selector variable)
*/
assert(glb_declared==0);
begdseg();
for (fsa=sc_automaton_tab.next; fsa!=NULL; fsa=fsa->next) {
defstorage();
stgwrite("0\t; automaton ");
if (strlen(fsa->name)==0)
stgwrite("(anonymous)");
else
stgwrite(fsa->name);
stgwrite("\n");
fsa->value=glb_declared*sizeof(cell);
glb_declared++;
} /* for */
/* write stubs and jump tables for all state functions */
begcseg();
for (sym=root->next; sym!=NULL; sym=sym->next) {
if (sym->ident==iFUNCTN && (sym->usage & (uPUBLIC | uREAD))!=0 && sym->states!=NULL) {
stlist=sym->states->next;
assert(stlist!=NULL); /* there should be at least one state item */
listid=stlist->index;
assert(listid==-1 || listid>0);
if (listid==-1 && stlist->next!=NULL) {
/* first index is the "fallback", take the next one (if available) */
stlist=stlist->next;
listid=stlist->index;
} /* if */
if (listid==-1) {
/* first index is the fallback, there is no second... */
strcpy(stlist->name,"0"); /* insert dummy label number */
/* this is an error, but we postpone adding the error message until the
* function definition
*/
continue;
} /* if */
/* generate label numbers for all statelist ids */
for (stlist=sym->states->next; stlist!=NULL; stlist=stlist->next) {
assert(strlen(stlist->name)==0);
strcpy(stlist->name,itoh(getlabel()));
} /* for */
if (strcmp(sym->name,uENTRYFUNC)==0)
continue; /* do not generate stubs for this special function */
sym->addr=code_idx; /* fix the function address now */
/* get automaton id for this function */
assert(listid>0);
fsa_id=state_getfsa(listid);
assert(fsa_id>=0); /* automaton 0 exists */
fsa=automaton_findid(fsa_id);
/* count the number of states actually used; at the sane time, check
* whether there is a default state function
*/
statecount=0;
strcpy(lbl_default,itoh(lbl_nostate));
for (stlist=sym->states->next; stlist!=NULL; stlist=stlist->next) {
if (stlist->index==-1) {
assert(strlen(stlist->name)<sizeof lbl_default);
strcpy(lbl_default,stlist->name);
} else {
statecount+=state_count(stlist->index);
} /* if */
} /* for */
/* generate a stub entry for the functions */
stgwrite("\tload.pri ");
outval(fsa->value,FALSE);
stgwrite("\t; ");
stgwrite(sym->name);
stgwrite("\n");
code_idx+=opcodes(1)+opargs(1); /* calculate code length */
lbl_table=getlabel();
ffswitch(lbl_table);
/* generate the jump table */
setlabel(lbl_table);
ffcase(statecount,lbl_default,TRUE);
for (state=sc_state_tab.next; state!=NULL; state=state->next) {
if (state->index==fsa_id) {
/* find the label for this list id */
for (stlist=sym->states->next; stlist!=NULL; stlist=stlist->next) {
if (stlist->index!=-1 && state_inlist(stlist->index,(int)state->value)) {
ffcase(state->value,stlist->name,FALSE);
break;
} /* if */
} /* for */
if (stlist==NULL && strtol(lbl_default,NULL,16)==lbl_nostate)
error(230,state->name,sym->name); /* unimplemented state, no fallback */
} /* if (state belongs to automaton of function) */
} /* for (state) */
stgwrite("\n");
} /* if (is function, used & having states) */
} /* for (sym) */
}