treat -> properly

closes #103

src/parse/expr.rs

@@ -835,12 +835,15 @@ impl<I: Iterator<Item = Lexeme>> Parser<I> {
                             continue;
                         }
                     };
+                    // mostly copied from Token::Star in prefix_expr
                     let expr = Expr {
-                        constexpr: false,
-                        location,
+                        constexpr: expr.constexpr,
+                        lval: false,
                         ctype: struct_type,
-                        lval: true,
-                        expr: ExprType::Deref(Box::new(expr)),
+                        location,
+                        // this is super hacky but the only way I can think of to prevent
+                        // https://github.com/jyn514/rcc/issues/90
+                        expr: ExprType::Noop(Box::new(expr.rval())),
                     };
                     self.struct_member(expr, id, location)?
                 }

tests/runner-tests/expr/pointers/7.c

@@ -0,0 +1,7 @@
+// code: 1
+struct s {
+        int i, j;
+} my_s, *my_sp = &my_s;
+int main() {
+        return my_sp->j = 1;
+}

tests/runner-tests/expr/pointers/8.c

@@ -0,0 +1,15 @@
+// code: 1
+typedef unsigned int __uid_t;
+extern __uid_t getuid (void) ;
+
+struct passwd {
+  char *pw_name;
+  char *pw_passwd;
+};
+
+extern struct passwd *getpwuid (__uid_t __uid);
+extern int puts (const char *__s);
+
+int main(void) {
+  return puts(getpwuid(getuid())->pw_name) >= 0;
+}