[libc-commits] [libc] [libc] Expand usage of libc null checks. (PR #116262)

[Aly ElAshram via libc-commits]

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@@ -9,11 +9,14 @@
 #include "src/string/memrchr.h"
 #include "src/__support/common.h"
 #include "src/__support/macros/config.h"
+#include "src/__support/macros/null_check.h"
 #include <stddef.h>
 
 namespace LIBC_NAMESPACE_DECL {
 
 LLVM_LIBC_FUNCTION(void *, memrchr, (const void *src, int c, size_t n)) {
+  LIBC_CRASH_ON_NULLPTR(src);
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AlyElashram wrote:

These functions are not mentioned in this doc [here](https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3322.pdf) , but they are different variants of the same function. 

memrchr for example , is a variant of memchr and memchr is mentioned in the doc. 

I'm not sure if we should include the variants or follow the document strictly @lntue . 


https://github.com/llvm/llvm-project/pull/116262