Import official C23 code examples for Modern C (Jens Gustedt, 2024)HEADupstream-importmain

- Add official C source files, Makefile, c23-fallback.h, and LICENSE
- Update README.md with study mirror notice

1 files changed, 37 insertions, 0 deletions

diff --git a/crash.h b/crash.h
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+#ifndef CRASH_H
+#define CRASH_H 1
+
+/**
+ ** @brief enable alignment check for i386 processors
+ **
+ ** Intel's i386 processor family is quite tolerant in accepting
+ ** misalignment of data. This can lead to irritating bugs when ported
+ ** to other architectures that are not as tolerant.
+ **
+ ** This function enables a check for this problem also for this
+ ** family or processors, such that you can be sure to detect this
+ ** problem early.
+ **
+ ** I found that code on Ygdrasil's blog:
+ ** http://orchistro.tistory.com/206
+ **/
+
+inline
+void enable_alignment_check(void) {
+#if defined(__GNUC__)
+# if defined(__x86_64__)
+  __asm__("pushf\n"
+          "\torl $0x40000, (%%rsp)\n"
+          "\tpopf"
+          : : : "cc");
+# elif defined(__i386__)
+  __asm__("pushf\n"
+          "\torl $0x40000, (%%esp)\n"
+          "\tpopf"
+          : : : "cc");
+# endif
+#endif
+}
+
+
+#endif