chibicc/type.c
Rui Ueyama e6307ad374 Add comma operator
This patch allows writing a comma expression on the left-hand side
of an assignment expression. This is called the "generalized lvalue"
which is a deprecated GCC language extension. I'm implementing it
anyway because it's useful to implement other features.
2020-10-15 14:22:16 +09:00

109 lines
2.2 KiB
C

#include "chibicc.h"
Type *ty_char = &(Type){TY_CHAR, 1};
Type *ty_int = &(Type){TY_INT, 8};
bool is_integer(Type *ty) {
return ty->kind == TY_CHAR || ty->kind == TY_INT;
}
Type *copy_type(Type *ty) {
Type *ret = calloc(1, sizeof(Type));
*ret = *ty;
return ret;
}
Type *pointer_to(Type *base) {
Type *ty = calloc(1, sizeof(Type));
ty->kind = TY_PTR;
ty->size = 8;
ty->base = base;
return ty;
}
Type *func_type(Type *return_ty) {
Type *ty = calloc(1, sizeof(Type));
ty->kind = TY_FUNC;
ty->return_ty = return_ty;
return ty;
}
Type *array_of(Type *base, int len) {
Type *ty = calloc(1, sizeof(Type));
ty->kind = TY_ARRAY;
ty->size = base->size * len;
ty->base = base;
ty->array_len = len;
return ty;
}
void add_type(Node *node) {
if (!node || node->ty)
return;
add_type(node->lhs);
add_type(node->rhs);
add_type(node->cond);
add_type(node->then);
add_type(node->els);
add_type(node->init);
add_type(node->inc);
for (Node *n = node->body; n; n = n->next)
add_type(n);
for (Node *n = node->args; n; n = n->next)
add_type(n);
switch (node->kind) {
case ND_ADD:
case ND_SUB:
case ND_MUL:
case ND_DIV:
case ND_NEG:
node->ty = node->lhs->ty;
return;
case ND_ASSIGN:
if (node->lhs->ty->kind == TY_ARRAY)
error_tok(node->lhs->tok, "not an lvalue");
node->ty = node->lhs->ty;
return;
case ND_EQ:
case ND_NE:
case ND_LT:
case ND_LE:
case ND_NUM:
case ND_FUNCALL:
node->ty = ty_int;
return;
case ND_VAR:
node->ty = node->var->ty;
return;
case ND_COMMA:
node->ty = node->rhs->ty;
return;
case ND_ADDR:
if (node->lhs->ty->kind == TY_ARRAY)
node->ty = pointer_to(node->lhs->ty->base);
else
node->ty = pointer_to(node->lhs->ty);
return;
case ND_DEREF:
if (!node->lhs->ty->base)
error_tok(node->tok, "invalid pointer dereference");
node->ty = node->lhs->ty->base;
return;
case ND_STMT_EXPR:
if (node->body) {
Node *stmt = node->body;
while (stmt->next)
stmt = stmt->next;
if (stmt->kind == ND_EXPR_STMT) {
node->ty = stmt->lhs->ty;
return;
}
}
error_tok(node->tok, "statement expression returning void is not supported");
return;
}
}