[sanitizer] Implement reallocarray.

Summary:
It's a cross of calloc and realloc. Sanitizers implement calloc-like check for size
overflow.

Reviewers: vitalybuka, kcc

Subscribers: kubamracek, #sanitizers, llvm-commits

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D61108

llvm-svn: 359708

1 files changed, 19 insertions, 0 deletions

diff --git a/compiler-rt/test/sanitizer_common/TestCases/reallocarray-overflow.cc b/compiler-rt/test/sanitizer_common/TestCases/reallocarray-overflow.cc
new file mode 100644
index 00000000000..245a5b47ab2
--- /dev/null
+++ b/compiler-rt/test/sanitizer_common/TestCases/reallocarray-overflow.cc
@@ -0,0 +1,19 @@
+// RUN: %clangxx  -O0 %s -o %t
+// RUN: %env_tool_opts=allocator_may_return_null=0 not %run %t 2>&1 | FileCheck %s
+// RUN: %env_tool_opts=allocator_may_return_null=1 %run %t 2>&1 | FileCheck %s --check-prefix=CHECK-NULL
+
+// REQUIRES: stable-runtime && !ubsan && !darwin
+
+#include <stdio.h>
+
+extern "C" void *reallocarray(void *, size_t, size_t);
+
+int main() {
+  void *p = reallocarray(nullptr, -1, 1000);
+  // CHECK: {{ERROR: .*Sanitizer: reallocarray parameters overflow: count \* size \(.* \* 1000\) cannot be represented in type size_t}}
+
+  printf("reallocarray returned: %zu\n", (size_t)p);
+  // CHECK-NULL: reallocarray returned: 0
+
+  return 0;
+}