From b3e9e62599532050fc776c5e8f076915b56c2235 Mon Sep 17 00:00:00 2001 From: David Faulkner Date: Fri, 7 Aug 2026 23:40:47 -0500 Subject: Import official C23 code examples for Modern C (Jens Gustedt, 2024) - Add official C source files, Makefile, c23-fallback.h, and LICENSE - Update README.md with study mirror notice --- crash.c | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) create mode 100644 crash.c (limited to 'crash.c') diff --git a/crash.c b/crash.c new file mode 100644 index 0000000..3a99d9e --- /dev/null +++ b/crash.c @@ -0,0 +1,33 @@ +#include "c23-fallback.h" +#include +#include +#include +#include +#include "crash.h" + +void enable_alignment_check(void); +typedef complex double cdbl; + +int main(void) { + enable_alignment_check(); + /* An overlay of complex values and bytes. */ + union { + cdbl val[2]; + unsigned char buf[sizeof(cdbl[2])]; + } toocomplex = { + .val = { 0.5 + 0.5*I, 0.75 + 0.75*I, }, + }; + printf("size/alignment: %zu/%zu\n", + sizeof(cdbl), alignof(cdbl)); + /* Run over all offsets, and crash on misalignment. */ + for (size_t offset = sizeof(cdbl); offset; offset /=2) { + printf("offset\t%zu:\t", offset); + fflush(stdout); + cdbl* bp = (cdbl*)(&toocomplex.buf[offset]); // align! + printf("%g\t+%gI\t", creal(*bp), cimag(*bp)); + fflush(stdout); + *bp *= *bp; + printf("%g\t+%gI", creal(*bp), cimag(*bp)); + fputc('\n', stdout); + } +} -- cgit v1.2.3