fix: apply proper offset for pointers in unary operations (#45)

keyvank · Nov 8, 2024 · ccd84ec · ccd84ec
1 parent 30e785e
commit ccd84ec
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Showing 5 changed files with 338 additions and 254 deletions.
diff --git a/examples/inp_pointer.c b/examples/inp_pointer.c
@@ -14,6 +14,9 @@ int main()
         printf("*a: %d\n", *a++);
     }
 
+    printf("*--a %d\n", *--a);
+    printf("*--a %d\n", *--a);
+
     char *s = (char *)malloc(10 * sizeof(char));
     s[0] = '1';
     s[1] = 'h';

diff --git a/parser/expr/expr.c b/parser/expr/expr.c
@@ -110,6 +110,13 @@ apply_result *unary_op_apply(parser_node *node, context *ctx)
 
     int op = unary_op->op;
 
+    int unit = 1;
+    if (operand->type->kind == TYPE_POINTER)
+    {
+        general_type *type = ((node_type *)operand->type->data)->type;
+        unit = type->size(type, ctx);
+    }
+
     if (op == TKN_MIN)
     {
         add_text(ctx, "neg rax");
@@ -122,12 +129,12 @@ apply_result *unary_op_apply(parser_node *node, context *ctx)
     }
     else if (op == TKN_MINMIN)
     {
-        add_text(ctx, "sub rax, 1");
+        add_text(ctx, "sub rax, %d", unit);
         move_reg_to_var(ctx, operand, "rax");
     }
     else if (op == TKN_PLUSPLUS)
     {
-        add_text(ctx, "add rax, 1");
+        add_text(ctx, "add rax, %d", unit);
         move_reg_to_var(ctx, operand, "rax");
     }