[clang] [Clang][attr] Add 'kcfi_salt' attribute (PR #141846)

[Kees Cook via cfe-commits]

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@@ -0,0 +1,190 @@
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -emit-llvm -fsanitize=kcfi -o - %s | FileCheck %s
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -emit-llvm -fsanitize=kcfi -x c++ -o - %s | FileCheck %s --check-prefixes=CHECK,MEMBER
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -emit-llvm -fsanitize=kcfi -fpatchable-function-entry-offset=3 -o - %s | FileCheck %s --check-prefixes=CHECK,OFFSET
+
+// Note that the interleving of functions, which normally would be in sequence,
+// is due to the fact that Clang outputs them in a non-sequential order.
+
+#if !__has_feature(kcfi)
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kees wrote:

The prototype mismatch at assignment type is a really good question. I hadn't considered this at all, but yes, it would really be a nice addition to catch misuse at build time. Is it complex to add?

https://github.com/llvm/llvm-project/pull/141846