/**
* Add an identifier to the symbol table and store its offset in the activation record.
* This function is called by dlinkApply1.
*
* @param node a node on a linked list containing the symbol table index of a variable
* delcared in a program
* @param data a structure containing the symbol table index of the type of the variable,
* the symbol table, and the current offset in the activation record.
*/
void addIdToSymtab(DNode node, AddIdStructPtr data) {
int symIndex = (int)dlinkNodeAtom(node);
int typeIndex = (int)SymGetFieldByIndex(data->idSymtab,symIndex,SYMTAB_TYPE_INDEX_FIELD);
if (typeIndex == -1) {
SymPutFieldByIndex(data->idSymtab,symIndex,SYMTAB_TYPE_INDEX_FIELD,(Generic)data->typeIndex);
typeIndex = data->typeIndex;
}
int size = (int)SymGetFieldByIndex(data->typeSymtab,typeIndex,SYMTAB_SIZE_FIELD);
SymPutFieldByIndex(data->idSymtab,symIndex,SYMTAB_OFFSET_FIELD,(Generic)(data->offset));
data->offset += size;
}
/**
* Get the symbol table index of a free integer register
*
* @param symtab a symbol table
* @return the symbol table index of a free integer register
*/
int getFreeIntegerRegisterIndex(SymTable symtab) {
int reg = allocateIntegerRegister();
char* symReg = getIntegerRegisterName(reg);
int regIndex;
if ((regIndex = SymQueryIndex(symtab,symReg)) == SYM_INVALID_INDEX) {
regIndex = SymIndex(symtab,symReg);
SymPutFieldByIndex(symtab,regIndex,SYMTAB_REGISTER_INDEX_FIELD,(Generic)reg);
SymPutFieldByIndex(symtab,regIndex,SYMTAB_TYPE_INDEX_FIELD,
(Generic)SymQueryIndex(symtab,SYMTAB_INTEGER_TYPE_STRING));
}
return regIndex;
}
/**
* emitPostCall
*
* Save callee-saved regs
* extend AR for locals
* find static data area
* initialize locals
* fall through to code
* @return index to label in symbol table for caller methods
*/
void emitPostCall(DList instList, SymtabStack symtabStack, int index, int frameSize){
SymTable symtab = currentSymtab(symtabStack);
SymTable symtab_0 = lastSymtab(symtabStack);
char* name = (char*)SymGetFieldByIndex(symtab_0, index,SYM_NAME_FIELD);
char* inst = nssave(2,name,":");
dlinkAppend(instList,dlinkNodeAlloc(inst));
//save $ra
inst = ssave("\tsw $ra,76($sp)");
dlinkAppend(instList,dlinkNodeAlloc(inst));
char regN[5];
char frameStr[10];
int si = 0;
//save s0-s7 regs
for( ; si<8; si++){
sprintf(regN,"$s%d,%d($sp)",si,(si*4)+4);
inst = nssave(2,"\tsw ",regN);
dlinkAppend(instList,dlinkNodeAlloc(inst));
}
inst = ssave("\tmove $fp,$sp");
dlinkAppend(instList,dlinkNodeAlloc(inst));
//allocate room for any local variables
if (frameSize != 0) {
sprintf(frameStr,"%d",frameSize);
inst = nssave(2,"\taddi $sp,$sp,",frameStr);
dlinkAppend(instList,dlinkNodeAlloc(inst));
//store any local variables on the stack(kind of)
int i = 0;
int max = SymMaxIndex(symtab);
int offset = 0;
for(;i<=max;i++)
{
offset = -(int)SymGetFieldByIndex(symtab,i,SYMTAB_OFFSET_FIELD);
SymPutFieldByIndex(symtab,i,SYMTAB_OFFSET_FIELD,(Generic)offset);
}
}
}
/**
* Push a new symbol table on the stack when entering a new scope region
*
* @param stack a stack of symbol tables
* @return a new symbol table
*/
SymTable beginScope(SymtabStack stack) {
SymTable symtab = SymInit(SYMTABLE_SIZE);
SymInitField(symtab,SYMTAB_OFFSET_FIELD,(Generic)-1,NULL);
SymInitField(symtab,SYMTAB_REGISTER_INDEX_FIELD,(Generic)-1,NULL);
int intIndex = SymIndex(symtab,SYMTAB_INTEGER_TYPE_STRING);
int errorIndex = SymIndex(symtab,SYMTAB_ERROR_TYPE_STRING);
int voidIndex = SymIndex(symtab,SYMTAB_VOID_TYPE_STRING);
SymPutFieldByIndex(symtab,intIndex,SYMTAB_SIZE_FIELD,(Generic)INTEGER_SIZE);
SymPutFieldByIndex(symtab,errorIndex,SYMTAB_SIZE_FIELD,(Generic)0);
SymPutFieldByIndex(symtab,voidIndex,SYMTAB_SIZE_FIELD,(Generic)0);
SymPutFieldByIndex(symtab,intIndex,SYMTAB_BASIC_TYPE_FIELD,(Generic)INTEGER_TYPE);
SymPutFieldByIndex(symtab,errorIndex,SYMTAB_BASIC_TYPE_FIELD,(Generic)ERROR_TYPE);
SymPutFieldByIndex(symtab,voidIndex,SYMTAB_BASIC_TYPE_FIELD,(Generic)VOID_TYPE);
dlinkPush(dlinkNodeAlloc((Generic)symtab),stack);
int *size = (int*)dlinkListAtom(stack);
(*size)++;
return symtab;
}
