Secure __next_prime from overflowing
llvm-svn: 117650
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: 5ec18264291e75ac807adbcc448086b10a31b952
diff --git a/src/hash.cpp b/src/hash.cpp
index dd4e8e3..6bd9c3b 100644
--- a/src/hash.cpp
+++ b/src/hash.cpp
@@ -9,6 +9,7 @@
#include "__hash_table"
#include "algorithm"
+#include "stdexcept"
_LIBCPP_BEGIN_NAMESPACE_STD
@@ -143,6 +144,26 @@
// are fewer potential primes to search, and fewer potential primes to divide
// against.
+inline _LIBCPP_INLINE_VISIBILITY
+void
+__check_for_overflow(size_t N, integral_constant<size_t, 32>)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+ if (N > 0xFFFFFFFB)
+ throw overflow_error("__next_prime overflow");
+#endif
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+void
+__check_for_overflow(size_t N, integral_constant<size_t, 64>)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+ if (N > 0xFFFFFFFFFFFFFFC5ull)
+ throw overflow_error("__next_prime overflow");
+#endif
+}
+
size_t
__next_prime(size_t n)
{
@@ -152,6 +173,9 @@
if (n <= small_primes[N-1])
return *std::lower_bound(small_primes, small_primes + N, n);
// Else n > largest small_primes
+ // Check for overflow
+ __check_for_overflow(n, integral_constant<size_t,
+ sizeof(n) * __CHAR_BIT__>());
// Start searching list of potential primes: L * k0 + indices[in]
const size_t M = sizeof(indices) / sizeof(indices[0]);
// Select first potential prime >= n