[libc++abi] Use fallback_malloc to allocate __cxa_eh_globals in case of dynamic memory exhaustion.

Throwing an exception for the first time may lead to call calloc to
allocate memory for __cxa_eh_globals. If the memory pool is exhausted
at that moment, it results in abnormal termination of the program.

This patch addresses the issue by using fallback_malloc in that case.

Differential Revision: https://reviews.llvm.org/D17815

llvm-svn: 282692

1 files changed, 32 insertions, 0 deletions

diff --git a/libcxxabi/test/test_exception_storage_nodynmem.pass.cpp b/libcxxabi/test/test_exception_storage_nodynmem.pass.cpp
new file mode 100644
index 00000000000..5c6eeacc628
--- /dev/null
+++ b/libcxxabi/test/test_exception_storage_nodynmem.pass.cpp
@@ -0,0 +1,32 @@
+//===--------------- test_exception_storage_nodynmem.cpp ------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include <assert.h>
+#include <cstdlib>
+
+static bool OverwrittenCallocCalled = false;
+
+// Override calloc to simulate exhaustion of dynamic memory
+void *calloc(size_t, size_t) {
+    OverwrittenCallocCalled = true;
+    return 0;
+}
+
+int main(int argc, char *argv[]) {
+    // Run the test a couple of times
+    // to ensure that fallback memory doesn't leak.
+    for (int I = 0; I < 1000; ++I)
+        try {
+            throw 42;
+        } catch (...) {
+        }
+
+    assert(OverwrittenCallocCalled);
+    return 0;
+}