Module Name: src
Committed By: rillig
Date: Thu May 2 20:03:33 UTC 2024
Modified Files:
src/tests/usr.bin/xlint/lint1: expr_sizeof.c
Log Message:
tests/lint: demonstrate wrong struct size calculation
To generate a diff of this commit:
cvs rdiff -u -r1.15 -r1.16 src/tests/usr.bin/xlint/lint1/expr_sizeof.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/tests/usr.bin/xlint/lint1/expr_sizeof.c
diff -u src/tests/usr.bin/xlint/lint1/expr_sizeof.c:1.15 src/tests/usr.bin/xlint/lint1/expr_sizeof.c:1.16
--- src/tests/usr.bin/xlint/lint1/expr_sizeof.c:1.15 Wed Mar 13 06:56:24 2024
+++ src/tests/usr.bin/xlint/lint1/expr_sizeof.c Thu May 2 20:03:33 2024
@@ -1,4 +1,4 @@
-/* $NetBSD: expr_sizeof.c,v 1.15 2024/03/13 06:56:24 rillig Exp $ */
+/* $NetBSD: expr_sizeof.c,v 1.16 2024/05/02 20:03:33 rillig Exp $ */
# 3 "expr_sizeof.c"
/*
@@ -213,3 +213,53 @@ sizeof_array_parameter(short arr[12345])
/* expect+1: error: negative array dimension (-2) [20] */
typedef int sizeof_arr_elem[-(int)(sizeof *arr)];
}
+
+
+void
+sequence_of_structs(void)
+{
+ typedef unsigned char uint8_t;
+ typedef short unsigned int uint16_t;
+ typedef unsigned int uint32_t;
+ typedef long unsigned int uint64_t;
+ typedef unsigned long size_t;
+
+ union fp_addr {
+ uint64_t fa_64;
+ struct {
+ uint32_t fa_off;
+ uint16_t fa_seg;
+ uint16_t fa_opcode;
+ } fa_32;
+ } __packed _Alignas(4);
+
+ struct fpacc87 {
+ uint64_t f87_mantissa;
+ uint16_t f87_exp_sign;
+ } __packed _Alignas(2);
+
+ // FIXME: This otherwise unused struct declaration influences the
+ // offsets checked below. Without this struct, sizeof(struct save87)
+ // is calculated correctly as 108 below.
+ struct fpaccfx {
+ struct fpacc87 r _Alignas(16);
+ };
+
+ struct save87 {
+ uint16_t s87_cw _Alignas(4);
+ uint16_t s87_sw _Alignas(4);
+ uint16_t s87_tw _Alignas(4);
+ union fp_addr s87_ip;
+ union fp_addr s87_dp;
+ struct fpacc87 s87_ac[8];
+ };
+
+ /* expect+1: error: negative array dimension (-20) [20] */
+ typedef int o1[-(int)((size_t)(unsigned long)(&(((struct save87 *)0)->s87_dp)))];
+ // FIXME: must be 28.
+ /* expect+1: error: negative array dimension (-32) [20] */
+ typedef int o2[-(int)((size_t)(unsigned long)(&(((struct save87 *)0)->s87_ac)))];
+ // FIXME: must be 108.
+ /* expect+1: error: negative array dimension (-112) [20] */
+ typedef int reveal[-(int)sizeof(struct save87)];
+}
