/**
* Find the topmost symbol table that contains an entry for a string
*
* @param stack a stack of symbol tables
* @return the symbol table containing the string or null
*/
SymTable findSymtab(SymtabStack stack, char* key) {
DNode node = dlinkHead(stack);
while (node != NULL) {
if (SymQueryIndex((SymTable)dlinkNodeAtom(node),key) != SYM_INVALID_INDEX)
break;
node = dlinkNext(node);
}
if (node != NULL)
return (SymTable)dlinkNodeAtom(node);
else
return NULL;
}
/**
* 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;
}
/**
* Print an assembly instruction to stdout. This function is only called by dlinkApply.
*
* @param inst a DNode containing an assembly instruction.
*/
static void printInstruction(DNode inst) {
fprintf(stdout,"%s\n",(char*)dlinkNodeAtom(inst));
}
/**
* Print a data declaration to stdout. This function is called by dlinkApply only.
*
* @param decl a DNode containing a data declaration
*/
static void printDataDeclaration(DNode decl) {
fprintf(stdout,"%s\n",(char*)dlinkNodeAtom(decl));
}
/**
* Pop a symbol table off of the stack when leave a scope region
*
* @param stack a stack of symbol tables
* @return the symbol table popped off of the stack
*/
SymTable endScope(SymtabStack stack) {
SymTable symtab = (SymTable)dlinkNodeAtom(dlinkPop(stack));
int *size = (int*)dlinkListAtom(stack);
(*size)--;
return symtab;
}
/**
* Get the symbol table on the bottom of the stack
*
* @param stack a stack of symbol tables
* @return the symbol table on the bottom of the stack
*/
SymTable lastSymtab(SymtabStack stack) {
return (SymTable)dlinkNodeAtom(dlinkTail(stack));
}
/**
* Get the most recently defined symbol table
*
* @param stack a stack of symbol tables
* @return the symbol table on top of the stack
*/
SymTable currentSymtab(SymtabStack stack) {
return (SymTable)dlinkNodeAtom(dlinkHead(stack));
}
