void stmt_call_print(struct expr *curr, FILE *f) {
switch(curr -> print_type) {
case 0:
fprintf(stderr, "Expr ");
expr_fprint(stderr, curr);
fprintf(stderr, " has bad print_type (%d)\n", curr -> print_type);
exit(1);
break;
case 1:
expr_func_codegen(curr, "print_boolean", f);
register_free(curr -> reg);
break;
case 2:
expr_func_codegen(curr, "print_character", f);
register_free(curr -> reg);
break;
case 3:
expr_func_codegen(curr, "print_integer", f);
register_free(curr -> reg);
break;
case 4:
expr_func_codegen(curr, "print_string", f);
register_free(curr -> reg);
break;
default:
fprintf(stderr, "Expr ");
expr_fprint(stderr, curr);
fprintf(stderr, " has bad print_type (%d)\n", curr -> print_type);
exit(1);
break;
}
}
void
print_expr(int mask, struct expr *e, int prevtoken)
{
if (!(cdebug & mask))
return;
expr_fprint(e, stdout);
}
static int expr_eq(struct expr *e1, struct expr *e2)
{
int res, old_count;
if (e1->type != e2->type)
return 0;
switch (e1->type) {
case E_EQUAL:
case E_GEQ:
case E_GTH:
case E_LEQ:
case E_LTH:
case E_UNEQUAL:
return e1->left.sym == e2->left.sym && e1->right.sym == e2->right.sym;
case E_SYMBOL:
return e1->left.sym == e2->left.sym;
case E_NOT:
return expr_eq(e1->left.expr, e2->left.expr);
case E_AND:
case E_OR:
e1 = expr_copy(e1);
e2 = expr_copy(e2);
old_count = trans_count;
expr_eliminate_eq(&e1, &e2);
res = (e1->type == E_SYMBOL && e2->type == E_SYMBOL &&
e1->left.sym == e2->left.sym);
expr_free(e1);
expr_free(e2);
trans_count = old_count;
return res;
case E_LIST:
case E_RANGE:
case E_NONE:
/* panic */;
}
if (DEBUG_EXPR) {
expr_fprint(e1, stdout);
printf(" = ");
expr_fprint(e2, stdout);
printf(" ?\n");
}
return 0;
}
static struct expr *expr_join_and(struct expr *e1, struct expr *e2)
{
struct expr *tmp;
struct symbol *sym1, *sym2;
if (expr_eq(e1, e2))
return expr_copy(e1);
if (e1->type != E_EQUAL && e1->type != E_UNEQUAL && e1->type != E_SYMBOL && e1->type != E_NOT)
return NULL;
if (e2->type != E_EQUAL && e2->type != E_UNEQUAL && e2->type != E_SYMBOL && e2->type != E_NOT)
return NULL;
if (e1->type == E_NOT) {
tmp = e1->left.expr;
if (tmp->type != E_EQUAL && tmp->type != E_UNEQUAL && tmp->type != E_SYMBOL)
return NULL;
sym1 = tmp->left.sym;
} else
sym1 = e1->left.sym;
if (e2->type == E_NOT) {
if (e2->left.expr->type != E_SYMBOL)
return NULL;
sym2 = e2->left.expr->left.sym;
} else
sym2 = e2->left.sym;
if (sym1 != sym2)
return NULL;
if (sym1->type != S_BOOLEAN && sym1->type != S_TRISTATE)
return NULL;
if ((e1->type == E_SYMBOL && e2->type == E_EQUAL && e2->right.sym == &symbol_yes) ||
(e2->type == E_SYMBOL && e1->type == E_EQUAL && e1->right.sym == &symbol_yes))
// (a) && (a='y') -> (a='y')
return expr_alloc_comp(E_EQUAL, sym1, &symbol_yes);
if ((e1->type == E_SYMBOL && e2->type == E_UNEQUAL && e2->right.sym == &symbol_no) ||
(e2->type == E_SYMBOL && e1->type == E_UNEQUAL && e1->right.sym == &symbol_no))
// (a) && (a!='n') -> (a)
return expr_alloc_symbol(sym1);
if ((e1->type == E_SYMBOL && e2->type == E_UNEQUAL && e2->right.sym == &symbol_mod) ||
(e2->type == E_SYMBOL && e1->type == E_UNEQUAL && e1->right.sym == &symbol_mod))
// (a) && (a!='m') -> (a='y')
return expr_alloc_comp(E_EQUAL, sym1, &symbol_yes);
if (sym1->type == S_TRISTATE) {
if (e1->type == E_EQUAL && e2->type == E_UNEQUAL) {
// (a='b') && (a!='c') -> 'b'='c' ? 'n' : a='b'
sym2 = e1->right.sym;
if ((e2->right.sym->flags & SYMBOL_CONST) && (sym2->flags & SYMBOL_CONST))
return sym2 != e2->right.sym ? expr_alloc_comp(E_EQUAL, sym1, sym2)
: expr_alloc_symbol(&symbol_no);
}
if (e1->type == E_UNEQUAL && e2->type == E_EQUAL) {
// (a='b') && (a!='c') -> 'b'='c' ? 'n' : a='b'
sym2 = e2->right.sym;
if ((e1->right.sym->flags & SYMBOL_CONST) && (sym2->flags & SYMBOL_CONST))
return sym2 != e1->right.sym ? expr_alloc_comp(E_EQUAL, sym1, sym2)
: expr_alloc_symbol(&symbol_no);
}
if (e1->type == E_UNEQUAL && e2->type == E_UNEQUAL &&
((e1->right.sym == &symbol_yes && e2->right.sym == &symbol_no) ||
(e1->right.sym == &symbol_no && e2->right.sym == &symbol_yes)))
// (a!='y') && (a!='n') -> (a='m')
return expr_alloc_comp(E_EQUAL, sym1, &symbol_mod);
if (e1->type == E_UNEQUAL && e2->type == E_UNEQUAL &&
((e1->right.sym == &symbol_yes && e2->right.sym == &symbol_mod) ||
(e1->right.sym == &symbol_mod && e2->right.sym == &symbol_yes)))
// (a!='y') && (a!='m') -> (a='n')
return expr_alloc_comp(E_EQUAL, sym1, &symbol_no);
if (e1->type == E_UNEQUAL && e2->type == E_UNEQUAL &&
((e1->right.sym == &symbol_mod && e2->right.sym == &symbol_no) ||
(e1->right.sym == &symbol_no && e2->right.sym == &symbol_mod)))
// (a!='m') && (a!='n') -> (a='m')
return expr_alloc_comp(E_EQUAL, sym1, &symbol_yes);
if ((e1->type == E_SYMBOL && e2->type == E_EQUAL && e2->right.sym == &symbol_mod) ||
(e2->type == E_SYMBOL && e1->type == E_EQUAL && e1->right.sym == &symbol_mod) ||
(e1->type == E_SYMBOL && e2->type == E_UNEQUAL && e2->right.sym == &symbol_yes) ||
(e2->type == E_SYMBOL && e1->type == E_UNEQUAL && e1->right.sym == &symbol_yes))
return NULL;
}
if (DEBUG_EXPR) {
printf("optimize (");
expr_fprint(e1, stdout);
printf(") && (");
expr_fprint(e2, stdout);
printf(")?\n");
}
return NULL;
}
/*
* e1 || e2 -> ?
*/
struct expr *expr_join_or(struct expr *e1, struct expr *e2)
{
struct expr *tmp;
struct symbol *sym1, *sym2;
if (expr_eq(e1, e2))
return expr_copy(e1);
if (e1->type != E_EQUAL && e1->type != E_UNEQUAL && e1->type != E_SYMBOL && e1->type != E_NOT)
return NULL;
if (e2->type != E_EQUAL && e2->type != E_UNEQUAL && e2->type != E_SYMBOL && e2->type != E_NOT)
return NULL;
if (e1->type == E_NOT) {
tmp = e1->left.expr;
if (tmp->type != E_EQUAL && tmp->type != E_UNEQUAL && tmp->type != E_SYMBOL)
return NULL;
sym1 = tmp->left.sym;
} else
sym1 = e1->left.sym;
if (e2->type == E_NOT) {
if (e2->left.expr->type != E_SYMBOL)
return NULL;
sym2 = e2->left.expr->left.sym;
} else
sym2 = e2->left.sym;
if (sym1 != sym2)
return NULL;
if (sym1->type != S_BOOLEAN && sym1->type != S_TRISTATE)
return NULL;
if (sym1->type == S_TRISTATE) {
if (e1->type == E_EQUAL && e2->type == E_EQUAL &&
((e1->right.sym == &symbol_yes && e2->right.sym == &symbol_mod) ||
(e1->right.sym == &symbol_mod && e2->right.sym == &symbol_yes))) {
// (a='y') || (a='m') -> (a!='n')
return expr_alloc_comp(E_UNEQUAL, sym1, &symbol_no);
}
if (e1->type == E_EQUAL && e2->type == E_EQUAL &&
((e1->right.sym == &symbol_yes && e2->right.sym == &symbol_no) ||
(e1->right.sym == &symbol_no && e2->right.sym == &symbol_yes))) {
// (a='y') || (a='n') -> (a!='m')
return expr_alloc_comp(E_UNEQUAL, sym1, &symbol_mod);
}
if (e1->type == E_EQUAL && e2->type == E_EQUAL &&
((e1->right.sym == &symbol_mod && e2->right.sym == &symbol_no) ||
(e1->right.sym == &symbol_no && e2->right.sym == &symbol_mod))) {
// (a='m') || (a='n') -> (a!='y')
return expr_alloc_comp(E_UNEQUAL, sym1, &symbol_yes);
}
}
if (sym1->type == S_BOOLEAN && sym1 == sym2) {
if ((e1->type == E_NOT && e1->left.expr->type == E_SYMBOL && e2->type == E_SYMBOL) ||
(e2->type == E_NOT && e2->left.expr->type == E_SYMBOL && e1->type == E_SYMBOL))
return expr_alloc_symbol(&symbol_yes);
}
if (DEBUG_EXPR) {
printf("optimize (");
expr_fprint(e1, stdout);
printf(") || (");
expr_fprint(e2, stdout);
printf(")?\n");
}
return NULL;
}
void stmt_codegen(struct stmt *s, FILE *f) {
if(!s) return;
switch(s -> kind) {
case STMT_DECL:
decl_codegen(s -> decl, f, SYMBOL_LOCAL);
break;
case STMT_EXPR:
expr_codegen(s -> expr, f);
register_free(s -> expr -> reg);
break;
case STMT_IF_ELSE: {
int done = assembly_jump_label++;
expr_codegen(s -> expr, f);
fprintf(f, "\tCMP $0, %s\n", register_name(s -> expr -> reg));
register_free(s -> expr -> reg);
if(s -> else_body) {
int el = assembly_jump_label++;
// jump to else
fprintf(f, "\tJE L%d\n", el);
stmt_codegen(s -> body, f);
assembly_comment(f, "\t# jump to done label (don't evaluate else label)\n");
fprintf(f, "JMP L%d\n", done);
assembly_comment(f, "\t# else label\n");
fprintf(f, "L%d:\n", el);
stmt_codegen(s -> else_body, f);
assembly_comment(f, "\t# done label\n");
fprintf(f, "L%d:\n", done);
}
else {
// jump to done
fprintf(f, "\tJE L%d\n", done);
stmt_codegen(s -> body, f);
assembly_comment(f, "\t# done label\n");
fprintf(f, "L%d:\n", done);
}
break;
}
case STMT_FOR: {
// check for nulls since all exprs optional
int loop = assembly_jump_label++;
int done = assembly_jump_label++;
if(s -> init_expr) {
expr_codegen(s -> init_expr, f);
register_free(s -> init_expr -> reg);
}
// loop label
assembly_comment(f, "\t# loop label\n");
fprintf(f, "L%d:\n", loop);
if(s -> expr) {
expr_codegen(s -> expr, f);
// don't need the return value
fprintf(f, "\tCMP $0, %s\n", register_name(s -> expr -> reg));
register_free(s -> expr -> reg);
assembly_comment(f, "\t# jump to done label (break condition)\n");
fprintf(f, "\tJE L%d\n", done);
}
stmt_codegen(s -> body, f);
if(s -> next_expr) {
expr_codegen(s -> next_expr, f);
register_free(s -> next_expr -> reg);
}
assembly_comment(f, "\t# unconditional jump to next loop\n");
fprintf(f, "JMP L%d\n", loop);
assembly_comment(f, "\t# done label\n");
fprintf(f, "L%d:\n", done);
break;
}
case STMT_WHILE:
fprintf(stderr, "CODEGEN_ERROR: cminor does not support while loops\n");
exit(1);
break;
case STMT_PRINT: {
struct expr *curr = s -> expr;
while(curr) {
expr_codegen(curr, f);
int count = 0;
if(ASSEMBLY_COMMENT_FLAG) {
fprintf(f, "\t# move arg %d (in %s) into %s\n", count, register_name(curr -> reg), register_arg_names[count]);
}
fprintf(f, "\tMOVQ %s, %s\n", register_name(curr -> reg), register_arg_names[count++]);
register_free(curr -> reg);
// calls func_codegen which save ret val in reg
// so need to free reg beforehand
stmt_call_print(curr, f);
curr = curr -> next;
}
break;
}
case STMT_RET:
expr_codegen(s -> expr, f);
if(ASSEMBLY_COMMENT_FLAG) {
fprintf(f, "\n\t# return statement (return ");
expr_fprint(f, s -> expr);
fprintf(f, ")\n");
}
if(s -> expr) {
fprintf(f, "\tMOVQ %s, %%rax\n", register_name(s -> expr -> reg));
register_free(s -> expr -> reg);
}
// postamble
assembly_comment(f, "\t### function postamble\n");
assembly_comment(f, "\t# restore callee-saved registers\n");
fprintf(f, "\tPOPQ %%r15\n");
fprintf(f, "\tPOPQ %%r14\n");
fprintf(f, "\tPOPQ %%r13\n");
fprintf(f, "\tPOPQ %%r12\n");
fprintf(f, "\tPOPQ %%rbx\n");
assembly_comment(f, "\t# reset stack to base pointer\n");
fprintf(f, "\tMOVQ %%rbp, %%rsp\n");
assembly_comment(f, "\t# restore the old base pointer\n");
fprintf(f, "\tPOPQ %%rbp\n");
fprintf(f, "\tRET\n");
break;
case STMT_BLOCK:
stmt_codegen(s -> body, f);
break;
}
stmt_codegen(s -> next, f);
}
void stmt_typecheck(struct stmt *s, struct type *ret, int *returned) {
if(!s) return;
switch(s -> kind) {
struct type *expr;
struct expr *curr;
case STMT_DECL:
decl_typecheck(s -> decl);
break;
case STMT_EXPR:
// need to typecheck, but don't need type
type_delete(expr_typecheck(s -> expr));
break;
case STMT_IF_ELSE:
expr = expr_typecheck(s -> expr);
if(expr -> kind != TYPE_BOOLEAN) {
fprintf(stderr, "TYPE_ERROR: cannot use a(n) ");
type_fprint(stderr, expr);
fprintf(stderr, " as the if statement expression (currently ");
expr_fprint(stderr, s -> expr);
fprintf(stderr, ") requires a boolean\n");
type_error_count++;
}
stmt_typecheck(s -> body, ret, returned);
stmt_typecheck(s -> else_body, ret, returned);
type_delete(expr);
break;
case STMT_FOR:
type_delete(expr_typecheck(s -> init_expr));
expr = expr_typecheck(s -> expr);
// need to check that the middle
// expression is actually there
if(expr && expr -> kind != TYPE_BOOLEAN) {
fprintf(stderr, "TYPE_ERROR: cannot use a ");
type_fprint(stderr, expr);
fprintf(stderr, " as the middle expression requires a boolean (or an empty expression)\n");
type_error_count++;
}
type_delete(expr);
type_delete(expr_typecheck(s -> next_expr));
stmt_typecheck(s -> body, ret, returned);
break;
case STMT_WHILE:
break;
case STMT_PRINT:
curr = s -> expr;
while(curr) {
expr = expr_typecheck(curr);
// pass type through new symbol
if(!type_is_atomic(expr)) {
fprintf(stderr, "TYPE_ERROR: cannot print (print ");
expr_fprint(stderr, s -> expr);
fprintf(stderr, ") a non-atomic value (");
type_fprint(stderr, expr);
fprintf(stderr, ")\n");
type_error_count++;
}
switch(expr -> kind) {
case TYPE_BOOLEAN:
curr -> print_type = 1;
break;
case TYPE_CHARACTER:
curr -> print_type = 2;
break;
case TYPE_INTEGER:
curr -> print_type = 3;
break;
case TYPE_STRING:
curr -> print_type = 4;
break;
case TYPE_ARRAY:
curr -> print_type = 0;
fprintf(stderr, "Bad entry into switch on type_kind in stmt_typecheck (case STMT_PRINT)\n");
exit(1);
break;
case TYPE_ARRAY_DECL:
curr -> print_type = 0;
fprintf(stderr, "Bad entry into switch on type_kind in stmt_typecheck (case STMT_PRINT)\n");
exit(1);
break;
case TYPE_FUNCTION:
curr -> print_type = 0;
fprintf(stderr, "Bad entry into switch on type_kind in stmt_typecheck (case STMT_PRINT)\n");
exit(1);
break;
case TYPE_VOID:
curr -> print_type = 0;
fprintf(stderr, "Bad entry into switch on type_kind in stmt_typecheck (case STMT_PRINT)\n");
exit(1);
break;
}
type_delete(expr);
curr = curr -> next;
}
break;
case STMT_RET:
// always set to 1
*returned = 1;
expr = expr_typecheck(s -> expr);
if(!s -> expr) {
type_delete(expr);
expr = type_create(TYPE_VOID, 0, 0, 0);
}
if(!type_compare(expr, ret)) {
fprintf(stderr, "TYPE_ERROR: the return statement (return ");
expr_fprint(stderr, s -> expr);
fprintf(stderr, ") does not match the function return type (");
type_fprint(stderr, ret);
fprintf(stderr, ")\n");
type_error_count++;
}
type_delete(expr);
break;
case STMT_BLOCK:
stmt_typecheck(s -> body, ret, returned);
break;
}
stmt_typecheck(s -> next, ret, returned);
}
void stmt_fprint(FILE *f, struct stmt *s, int indent) {
if(!s) return;
if(s -> kind != STMT_BLOCK)
fprint_indent(f, indent);
switch(s -> kind) {
case STMT_DECL:
decl_fprint(f, s -> decl, indent - 1);
/*don't print new line because decl always prints new lines*/
break;
case STMT_EXPR:
expr_fprint(f, s -> expr);
fprintf(f, ";\n");
break;
case STMT_IF_ELSE:
fprintf(f, "if(");
expr_fprint(f, s -> expr);
fprintf(f, ")");
stmt_fprint_body(f, s -> body, indent);
if(s -> else_body) {
fprint_indent(f, indent);
fprintf(f, "else");
stmt_fprint_body(f, s -> else_body, indent);
}
break;
case STMT_FOR:
fprintf(f, "for(");
expr_fprint(f, s -> init_expr);
fprintf(f, "; ");
expr_fprint(f, s -> expr);
fprintf(f, "; ");
expr_fprint(f, s -> next_expr);
fprintf(f, ")");
stmt_fprint_body(f, s -> body, indent);
break;
case STMT_WHILE:
/*
*while loops are not in the CMinor spec so this should not get called.
*if it does, it breaks immediately
*/
break;
case STMT_PRINT:
fprintf(f, "print");
if(s -> expr) {
fprintf(f, " ");
expr_fprint(f, s -> expr);
}
fprintf(f, ";\n");
break;
case STMT_RET:
fprintf(f, "return");
if(s -> expr) {
fprintf(f, " ");
expr_fprint(f, s -> expr);
}
fprintf(f, ";\n");
break;
case STMT_BLOCK:
fprintf(f, "{\n");
stmt_fprint(f, s -> body, indent + 1);
fprint_indent(f, indent);
fprintf(f, "}\n");
break;
}
stmt_fprint(f, s -> next, indent);
}