1 /* $NetBSD: gcc_init_compound_literal.c,v 1.6 2022/06/17 18:54:53 rillig Exp $ */ 2 # 3 "gcc_init_compound_literal.c" 3 4 /* 5 * C99 says in 6.7.8p4: 6 * 7 * All the expressions in an initializer for an object that has static 8 * storage duration shall be constant expressions or string literals. 9 * 10 * The term "constant expression" is defined in C99 6.6, where 6.6p9 allows 11 * "constant expressions" in initializers to also be an "address constant". 12 * Using these address constants, it is possible to reference an unnamed 13 * object created by a compound literal (C99 6.5.2.5), using either an 14 * explicit '&' or the implicit array-to-pointer conversion from C99 6.3.2.1. 15 * 16 * Before init.c 1.195 from 2021-04-17, lint failed with an assertion failure 17 * in check_global_variable, called by check_global_symbols since these 18 * temporary objects have neither storage class EXTERN nor STATIC. 19 */ 20 21 // Seen in sys/crypto/aes/aes_ccm.c. 22 const struct { 23 const unsigned char *ctxt; 24 } T = { 25 .ctxt = (const unsigned char[4]){ 26 1, 2, 3, 4 27 }, 28 }; 29 30 struct node { 31 int num; 32 struct node *left; 33 struct node *right; 34 }; 35 36 /* 37 * Initial tree for representing the decisions in the classic number guessing 38 * game often used in teaching the basics of programming. 39 */ 40 /* expect+1: warning: static variable 'guess' unused [226] */ 41 static const struct node guess = { 42 50, 43 &(struct node){ 44 25, 45 &(struct node){ 46 12, 47 (void *)0, 48 (void *)0, 49 }, 50 &(struct node){ 51 37, 52 (void *)0, 53 (void *)0, 54 }, 55 }, 56 (void *)0 57 }; 58