void Parser::whileStat() {
consume(TK_while);
int pos1 = emitHole();
int pos2 = HERE;
Value a = expr(syms->localsTop());
Vector<int> copyExp;
Vector<int> &code = proto->code;
while (code.size() > pos2) {
copyExp.push(code.pop());
}
block();
emitJump(pos1, JMP, UNUSED, HERE);
while (copyExp.size()) {
code.push(copyExp.pop());
}
emitJump(HERE, JT, a, pos2);
}
void Parser::ifStat() {
consume(TK_if);
Value a = expr(syms->localsTop());
int pos1 = emitHole();
block();
if (lexer->token == TK_else) {
int pos2 = emitHole();
emitJump(pos1, JF, a, HERE);
consume(TK_else);
if (lexer->token == '{') {
block();
} else {
ifStat();
}
emitJump(pos2, JMP, UNUSED, HERE);
} else {
emitJump(pos1, JF, a, HERE);
}
}
void Parser::forStat() {
consume(TK_for);
syms->enterBlock(false);
CERR(TOKEN != TK_NAME, E_FOR_NAME, VNIL);
Value name = lexer->info.name;
int slot = syms->localsTop();
advance();
consume(':'+TK_EQUAL);
patchOrEmitMove(slot+2, slot+2, expr(slot+2));
consume(':');
patchOrEmitMove(slot+3, slot+1, expr(slot+3));
int pos1 = emitHole();
int pos2 = HERE;
syms->set(name, slot);
syms->addLocalsTop(2);
insideBlock();
emitJump(HERE, LOOP, VAL_REG(slot), pos2);
emitJump(pos1, FOR, VAL_REG(slot), HERE);
syms->exitBlock(false);
}
void DFABytecodeCompiler::compileNode(unsigned index)
{
const DFANode& node = m_dfa.nodeAt(index);
// Record starting index for linking.
m_nodeStartOffsets[index] = m_bytecode.size();
for (uint64_t action : node.actions)
emitAppendAction(static_cast<unsigned>(action));
for (const auto& transition : node.transitions)
emitCheckValue(transition.key, transition.value);
if (node.hasFallbackTransition)
emitJump(node.fallbackTransition);
else
emitTerminate();
}
void codeGen(Node *root, FILE *ucoFile)
{
Node *p; // pointer for Node
int globalSize; // the size of global variables
file = ucoFile; //
rootTable = initSymbolTable();
// step 1: process the declaration part
for (p = root->son; p; p = p->next) {
if (p->token.tokenNumber == DCL) {
processDeclaration(rootTable, p->son);
} else if (p->token.tokenNumber == FUNC_DEF) {
processFuncHeader(rootTable, p->son);
} else {
icg_error(3);
}
}
globalSize = rootTable->offset - 1;
// step 2: process the function part
for (p = root->son; p; p = p->next) {
if (p->token.tokenNumber == FUNC_DEF) {
processFunction(rootTable, p);
}
}
display(rootTable, 0);
// step 3: generate codes for starting routine
// bgn globalSize
// ldp
// call main
// end
emit1("bgn", globalSize);
emit0("ldp");
emitJump("call", "main");
emit0("end");
}
void processStatement(SymbolTable *table, Node *ptr)
{
Node *p;
char label1[LABEL_SIZE]={0}, label2[LABEL_SIZE]={0};
switch(ptr->token.tokenNumber) {
case COMPOUND_ST:
p = ptr->son->next;
p = p->son;
while (p) {
processStatement(table, p);
p = p->next;
}
break;
case EXP_ST:
if (ptr->son != NULL) {
processOperator(table, ptr->son);
}
break;
case RETURN_ST:
if (ptr->son != NULL) {
p = ptr->son;
if (p->noderep == NONTERM) {
processOperator(table, p);
} else {
rv_emit(table, p);
}
emit0("retv");
} else
emit0("ret");
flag_returned=1;
break;
case IF_ST:
genLabel(label1);
processCondition(table, ptr->son);
emitJump("fjp", label1);
processStatement(table, ptr->son->next);
emitLabel(label1);
break;
case IF_ELSE_ST:
genLabel(label1);
genLabel(label2);
processCondition(table, ptr->son);
emitJump("fjp", label1);
processStatement(table, ptr->son->next);
emitJump("ujp", label2);
emitLabel(label1);
processStatement(table, ptr->son->next->next);
emitLabel(label2);
break;
case WHILE_ST:
genLabel(label1);
genLabel(label2);
emitLabel(label1);
processCondition(table, ptr->son);
emitJump("fjp", label2);
processStatement(table, ptr->son->next);
emitJump("ujp", label1);
emitLabel(label2);
break;
default:
fprintf(file, "not yet implemented.\n");
break;
}
}
void processOperator(SymbolTable *table, Node *ptr)
{
int stIndex;
switch(ptr->token.tokenNumber) {
case ASSIGN_OP: {
Node *lhs = ptr->son, *rhs = ptr->son->next;
if (lhs->noderep == NONTERM) {
lvalue = 1;
processOperator(table, lhs);
lvalue = 0;
}
if (rhs->noderep == NONTERM) {
processOperator(table, rhs);
} else {
rv_emit(table, rhs);
}
if (lhs->noderep == TERMINAL) {
stIndex = lookup(table, lhs->token.tokenValue);
if (stIndex == -1) {
fprintf(stderr, "undefined variable: %s\n", lhs->token.tokenValue);
return;
}
emit2("str", table->rows[stIndex].base, table->rows[stIndex].offset);
} else {
emit0("sti");
}
break;
}
case ADD_ASSIGN: case SUB_ASSIGN: case MUL_ASSIGN:
case DIV_ASSIGN: case MOD_ASSIGN: {
Node *lhs = ptr->son, *rhs = ptr->son->next;
int nodeNumber = ptr->token.tokenNumber;
ptr->token.tokenNumber = ASSIGN_OP;
if (lhs->noderep == NONTERM) {
lvalue = 1;
processOperator(table, lhs);
lvalue = 0;
}
ptr->token.tokenNumber = nodeNumber;
if (lhs->noderep == NONTERM) {
processOperator(table, lhs);
} else {
rv_emit(table, lhs);
}
if (rhs->noderep == NONTERM) {
processOperator(table, rhs);
} else {
rv_emit(table, rhs);
}
switch(ptr->token.tokenNumber) {
case ADD_ASSIGN: emit0("add"); break;
case SUB_ASSIGN: emit0("sub"); break;
case MUL_ASSIGN: emit0("mult"); break;
case DIV_ASSIGN: emit0("div"); break;
case MOD_ASSIGN: emit0("mod"); break;
}
if (lhs->noderep == TERMINAL) {
stIndex = lookup(table, lhs->token.tokenValue);
if (stIndex == -1) {
fprintf(file, "undefined variable: %s\n", lhs->son->token.tokenValue);
return;
}
emit2("str", table->rows[stIndex].base, table->rows[stIndex].offset);
} else {
emit0("sti");
}
break;
}
case ADD: case SUB: case MUL: case DIV: case MOD:
case EQ: case NE: case GT: case LT: case GE: case LE:
case LOGICAL_AND: case LOGICAL_OR: {
Node *lhs = ptr->son, *rhs = ptr->son->next;
if (lhs->noderep == NONTERM) {
processOperator(table, lhs);
} else {
rv_emit(table, lhs);
}
if (rhs->noderep == NONTERM) {
processOperator(table, rhs);
} else {
rv_emit(table, rhs);
}
switch(ptr->token.tokenNumber) {
case ADD: emit0("add"); break;
case SUB: emit0("sub"); break;
case MUL: emit0("mult"); break;
case DIV: emit0("div"); break;
case MOD: emit0("mod"); break;
case EQ: emit0("eq"); break;
case NE: emit0("ne"); break;
case GT: emit0("gt"); break;
case LT: emit0("lt"); break;
case GE: emit0("ge"); break;
case LE: emit0("le"); break;
case LOGICAL_AND: emit0("and"); break;
case LOGICAL_OR: emit0("or"); break;
}
break;
}
case UNARY_MINUS: case LOGICAL_NOT: {
Node *p = ptr->son;
if (p->noderep == NONTERM) {
processOperator(table, p);
} else {
rv_emit(table, p);
}
switch(ptr->token.tokenNumber) {
case UNARY_MINUS: emit0("neg"); break;
case LOGICAL_NOT: emit0("not"); break;
}
break;
}
case INDEX: {
Node *indexExp = ptr->son->next;
if (indexExp->noderep == NONTERM) processOperator(table, indexExp); else rv_emit(table, indexExp);
stIndex = lookup(table, ptr->son->token.tokenValue);
if (stIndex == -1) {
fprintf(file, "undefined variable: %s\n", ptr->son->token.tokenValue);
return;
}
emit2("lda", table->rows[stIndex].base, table->rows[stIndex].offset);
emit0("add");
if (!lvalue) {
emit0("ldi");
}
break;
}
case PRE_INC: case PRE_DEC: case POST_INC: case POST_DEC: {
Node *p = ptr->son;
Node *q;
int stIndex;
int amount = 1;
if (p->noderep == NONTERM) {
processOperator(table, p);
} else {
rv_emit(table, p);
}
q = p;
while (q->noderep != TERMINAL) {
q = q->son;
}
if (!q || (q->token.tokenNumber != IDENT)) {
fprintf(file, "increment/decrement operators can not be applied in expression\n");
return;
}
stIndex = lookup(table, q->token.tokenValue);
if (stIndex == -1) {
return;
}
switch(ptr->token.tokenNumber) {
case PRE_INC: emit0("inc"); break;
case PRE_DEC: emit0("dec"); break;
case POST_INC: emit0("inc"); break;
case POST_DEC: emit0("dec"); break;
}
if (p->noderep == TERMINAL) {
stIndex = lookup(table, p->token.tokenValue);
if (stIndex == -1) {
return;
}
emit2("str", table->rows[stIndex].base, table->rows[stIndex].offset);
} else if (p->token.tokenNumber == INDEX) {
lvalue = 1;
processOperator(table, p);
lvalue = 0;
emit0("swp");
emit0("sti");
} else fprintf(file, "error in increment/decrement operators\n");
break;
}
case CALL: {
Node *p = ptr->son;
char *functionName;
int stIndex;
int noArguments;
if (checkPredefined(table, p)) {
break;
}
functionName = p->token.tokenValue;
stIndex = lookup(rootTable, functionName);
if (stIndex == -1) {
fprintf(file, "%s: undefined function\n", functionName);
break;
}
noArguments = rootTable->rows[stIndex].width;
emit0("ldp");
p = p->next->son;
while (p) {
if (p->noderep == NONTERM) {
processOperator(table, p);
} else {
rv_emit(table, p);
}
noArguments--;
p = p->next;
}
if (noArguments > 0) {
fprintf(file, "%s: too few actual arguments\n", functionName);
}
if (noArguments < 0) {
fprintf(file, "%s: too many actual arguments\n", functionName);
}
emitJump("call", ptr->son->token.tokenValue);
break;
}
}
}
int checkPredefined(SymbolTable *table, Node *ptr)
{
Node *p=ptr;
char *functionName;
int noArguments;
int stIndex;
functionName = p->token.tokenValue;
if (strcmp(functionName, "read") == 0) {
noArguments = 1;
emit0("ldp");
p = p->next->son;
while (p) {
if (p->noderep == NONTERM) {
processOperator(table, p);
} else {
stIndex = lookup(table, p->token.tokenValue);
if (stIndex == -1) {
return 0;
}
emit2("lda", table->rows[stIndex].base, table->rows[stIndex].offset);
}
noArguments--;
p = p->next;
}
if (noArguments > 0) {
fprintf(file, "%s: too few actual arguments\n", functionName);
}
if (noArguments < 0) {
fprintf(file, "%s: too many actual arguments\n", functionName);
}
emitJump("call", functionName);
return 1;
} else if (strcmp(functionName, "write") == 0) {
noArguments = 1;
emit0("ldp");
p = p->next->son;
while (p) {
if (p->noderep == NONTERM) {
processOperator(table, p);
} else {
stIndex = lookup(table, p->token.tokenValue);
if (stIndex == -1) return 0;
emit2("lod", table->rows[stIndex].base, table->rows[stIndex].offset);
}
noArguments--;
p=p->next;
}
if (noArguments > 0) {
fprintf(file, "%s: too few actual arguments\n", functionName);
}
if (noArguments < 0) {
fprintf(file, "%s: too many actual arguments\n", functionName);
}
emitJump("call", functionName);
return 1;
} else if (strcmp(functionName, "lf") == 0) {
emitJump("call", functionName);
return 1;
}
return 0;
}