core-lightning/ccan/ccan/structeq/_info
Rusty Russell fed5a117e7 Update ccan/structeq.
structeq() is too dangerous: if a structure has padding, it can fail
silently.

The new ccan/structeq instead provides a macro to define foo_eq(),
which does the right thing in case of padding (which none of our
structures currently have anyway).

Upgrade ccan, and use it everywhere.  Except run-peer-wire.c, which
is only testing code and can use raw memcmp(): valgrind will tell us
if padding exists.

Interestingly, we still declared short_channel_id_eq, even though
we didn't define it any more!

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2018-07-04 23:57:00 +02:00

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#include "config.h"
#include <stdio.h>
#include <string.h>
/**
* structeq - bitwise comparison of structs.
*
* This is a replacement for memcmp, which checks the argument types are the
* same, and takes into account padding in the structure. When there is no
* padding, it becomes a memcmp at compile time (assuming a
* constant-optimizing compiler).
*
* License: BSD-MIT
* Author: Rusty Russell <rusty@rustcorp.com.au>
*
* Example:
* #include <ccan/structeq/structeq.h>
* #include <ccan/build_assert/build_assert.h>
* #include <assert.h>
*
* struct mydata {
* int start, end;
* };
* // Defines mydata_eq(a, b)
* STRUCTEQ_DEF(mydata, 0, start, end);
*
* int main(void)
* {
* struct mydata a, b;
*
* a.start = 100;
* a.end = 101;
*
* // They are equal.
* assert(mydata_eq(&a, &b));
*
* b.end++;
* // Now they are not.
* assert(!mydata_eq(&a, &b));
*
* return 0;
* }
*/
int main(int argc, char *argv[])
{
/* Expect exactly one argument */
if (argc != 2)
return 1;
if (strcmp(argv[1], "depends") == 0) {
printf("ccan/build_assert\n");
printf("ccan/cppmagic\n");
return 0;
}
return 1;
}