[libcxx-commits] [clang] [compiler-rt] [libcxx] [clang] Add unistd fortify checks and analyzer size constraints (PR #196499)

[Denys Fedoryshchenko via libcxx-commits]

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@@ -21,6 +21,6 @@ static_assert(std::__constexpr_wmemcmp(L"Banane", L"Bananf", 6) == -1, "");
 
 constexpr bool test_constexpr_wmemchr() {
   const wchar_t str[] = L"Banane";
-  return std::__constexpr_wmemchr(str, 'n', 6) == str + 2;
+  return std::__constexpr_wmemchr(str, L'n', 6) == str + 2;
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nuclearcat wrote:

Before commit `[clang][Sema] Add min/max operation size for fortify checks`, the memcpy/memmove/mempcpy fortify case in SemaChecking.cpp only computed DestinationSize and checked destination overflow.
After this commit, it also sets SourceSize = ComputeSizeArgument(1), and the new warn_fortify_destination_over_read diagnostic fires when SourceSize < MinOperationSize - which exposes the latent type mismatch in this test ('n' deduces _Up = char, so the internal __builtin_memcpy over-reads the 1-byte source).


https://github.com/llvm/llvm-project/pull/196499