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#include "parser.h"
#include "utils.h"
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
bool type_equals(Type *a, Type *b)
{
if (a == NULL && b == NULL)
return true;
if (a == NULL || b == NULL)
return false;
if (a->type == TYPE_ANY || b->type == TYPE_ANY)
return true;
return a->type == b->type && type_equals(a->ptr, b->ptr);
}
bool is_convertible(Type *from, Type *to)
{
if (from->type == TYPE_ANY || to->type == TYPE_ANY)
return true;
// TODO: Should we rause a warning if the target type is narrower
// than the source type?
if (is_int_type(from) && is_int_type(to))
return true;
return type_equals(from, to);
}
i64 size_for_type(Type *type)
{
switch (type->type)
{
case TYPE_INT: return 8;
case TYPE_PTR: return 8;
case TYPE_CHAR: return 1;
case TYPE_ARRAY: return type->array_size * size_for_type(type->ptr);
default: {
printf("Unknown type: %d\n", type->type);
assert(false && "Unreachable type");
}
}
}
Type *type_new(DataType type)
{
// For the core types, we don't need to allocate any memory, just
// return a pointer to a static instance.
static Type type_int = {.type = TYPE_INT, .ptr = NULL};
static Type type_char = {.type = TYPE_CHAR, .ptr = NULL};
static Type type_any = {.type = TYPE_ANY, .ptr = NULL};
if (type == TYPE_INT) return &type_int;
if (type == TYPE_CHAR) return &type_char;
if (type == TYPE_ANY) return &type_any;
Type *self = calloc(sizeof(Type), 1);
self->type = type;
return self;
}
Type *type_new_ptr(DataType type)
{
Type *self = type_new(TYPE_PTR);
self->ptr = type_new(type);
return self;
}
bool is_string_type(Type *type)
{
return type
&& type->type == TYPE_PTR
&& type->ptr->type == TYPE_CHAR;
}
bool is_int_type(Type *type)
{
switch (type->type)
{
case TYPE_INT:
case TYPE_CHAR:
return true;
default:
return false;
}
}
static char *data_type_to_str(DataType type)
{
switch (type)
{
case TYPE_NONE: return "void";
case TYPE_INT: return "int";
case TYPE_PTR: return "*";
case TYPE_ARRAY: return "array";
case TYPE_CHAR: return "char";
case TYPE_ANY: return "<@>";
default: assert(false && "Unreachable");
}
}
char *type_to_str(Type *type)
{
// FIXME: Handle array types.
// TODO: This allocates memory and we probably don't want to do that.
// TODO: Probably want to increase this size once we have longer types
char *str = calloc(sizeof(char), 32);
int ptr_count = 0;
for (; type->type == TYPE_PTR; type = type->ptr)
ptr_count++;
// FIXME: This is inefficient as all hell but this will only really be
// used for error reporting.
strcat(str, data_type_to_str(type->type));
for (int i = 0; i < ptr_count; i++)
strcat(str, "*");
return str;
}
Node *handle_unary_expr_types(Node *node, Token *token)
{
Type *old_type = node->unary_expr->expr_type;
if (node->type == OP_NOT) {
node->expr_type = type_new(TYPE_INT);
} else if (node->type == OP_ADDROF) {
Type *ptr = type_new(TYPE_PTR);
// The address of an array is a pointer to the first element
ptr->ptr = old_type->type == TYPE_ARRAY ? old_type->ptr : old_type;
node->expr_type = ptr;
} else if (node->type == OP_DEREF) {
if (old_type->type != TYPE_PTR)
die_location(token->loc, "Cannot dereference non-pointer type");
node->expr_type = old_type->ptr;
// If the dereferenced type is an array, we need to decay it to a
// pointer to the first element.
node = decay_array_to_pointer(node, token);
} else if (node->type == OP_NEG) {
if (old_type->type != TYPE_INT)
die_location(token->loc, "Cannot negate non-integer type");
node->expr_type = type_new(TYPE_INT);
} else {
// Default to not changing the type
node->expr_type = old_type;
}
return node;
}
Node *handle_binary_expr_types(Node *node, Token *token)
{
Type *left = node->binary.left->expr_type;
Type *right = node->binary.right->expr_type;
switch (node->type)
{
case OP_PLUS: {
if (is_int_type(left) && is_int_type(right)) {
node->expr_type = type_new(TYPE_INT);
} else if (left->type == TYPE_PTR && is_int_type(right)) {
node->expr_type = left;
// Pointer arithmetic!
if (size_for_type(left->ptr) != 1) {
Node *mul = Node_new(OP_MUL);
mul->binary.left = node->binary.right;
mul->binary.right = Node_from_int_literal(size_for_type(left->ptr));
node->binary.right = mul;
}
} else if (is_int_type(left) && right->type == TYPE_PTR) {
node->expr_type = right;
// Pointer arithmetic!
if (size_for_type(right->ptr) != 1) {
Node *mul = Node_new(OP_MUL);
mul->binary.left = node->binary.left;
mul->binary.right = Node_from_int_literal(size_for_type(right->ptr));
node->binary.left = mul;
}
} else {
die_location(token->loc, "Cannot add non-integer types");
}
} break;
case OP_MINUS: {
if (is_int_type(left) && is_int_type(right)) {
node->expr_type = type_new(TYPE_INT);
} else if (left->type == TYPE_PTR && is_int_type(right)) {
node->expr_type = left;
// Pointer arithmetic!
if (size_for_type(left->ptr) != 1) {
Node *mul = Node_new(OP_MUL);
mul->binary.left = node->binary.right;
mul->binary.right = Node_from_int_literal(size_for_type(left->ptr));
node->binary.right = mul;
}
} else if (is_int_type(left) && right->type == TYPE_PTR) {
node->expr_type = right;
// Pointer arithmetic!
if (size_for_type(right->ptr) != 1) {
Node *mul = Node_new(OP_MUL);
mul->binary.left = node->binary.left;
mul->binary.right = Node_from_int_literal(size_for_type(right->ptr));
node->binary.left = mul;
}
} else if (left->type == TYPE_PTR && right->type == TYPE_PTR) {
node->expr_type = type_new(TYPE_INT);
if (!type_equals(left->ptr, right->ptr))
die_location(token->loc, "Cannot subtract pointers of different types");
// Pointer arithmetic! (Divide by size of element)
if (size_for_type(left->ptr) != 1) {
Node *mul = Node_new(OP_MUL);
mul->binary.left = node->binary.left;
mul->binary.right = Node_from_int_literal(size_for_type(left->ptr));
node->binary.left = mul;
}
} else {
die_location(token->loc, "Cannot subtract non-integer types");
}
} break;
case OP_DIV:
case OP_MOD:
case OP_MUL: {
if (is_int_type(left) && is_int_type(right)) {
node->expr_type = left;
} else {
die_location(token->loc, "Cannot do operation `%s` non-integer types", node_type_to_str(node->type));
}
} break;
case OP_EQ:
case OP_NEQ:
case OP_LT:
case OP_GT:
case OP_LEQ:
case OP_GEQ:
case OP_AND:
case OP_OR: {
node->expr_type = type_new(TYPE_INT);
} break;
default:
die_location(token->loc, "Unknown binary expression type in handle_binary_expr_types\n");
}
return node;
}
Node *decay_array_to_pointer(Node *node, Token *token)
{
// We can only take the address of an lvalue, so we need to ensure that
if (is_lvalue(node->type) && node->expr_type->type == TYPE_ARRAY) {
Node *address = Node_new(OP_ADDROF);
address->unary_expr = node;
address = handle_unary_expr_types(address, token);
node = address;
}
return node;
}
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