Exception handling stuctures, and thread-local variables for exception handling

llvm-svn: 135586

1 files changed, 81 insertions, 0 deletions

diff --git a/libcxxabi/src/cxa_exception_storage.cpp b/libcxxabi/src/cxa_exception_storage.cpp
new file mode 100644
index 00000000000..01bf8a4779a
--- /dev/null
+++ b/libcxxabi/src/cxa_exception_storage.cpp
@@ -0,0 +1,81 @@
+//===--------------------- cxa_exception_storage.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.
+//
+//  
+//  This file implements the storage for the "Caught Exception Stack"
+//  http://www.codesourcery.com/public/cxx-abi/abi-eh.html (section 2.2.2)
+//  
+//===----------------------------------------------------------------------===//
+
+#include "cxa_exception.hpp"
+
+#ifdef HAS_THREAD_LOCAL
+
+namespace __cxxabiv1 {
+
+namespace {
+    __cxa_eh_globals * __globals () throw () {
+        static thread_local __cxa_eh_globals eh_globals;
+        return &eh_globals;
+        }
+    }
+
+extern "C" {
+    __cxa_eh_globals * __cxa_get_globals      () throw() { return __globals (); }
+    __cxa_eh_globals * __cxa_get_globals_fast () throw() { return __globals (); }
+    }
+}
+
+#else
+
+#include <pthread.h>
+#include <cstdlib>          // for calloc, free
+#include <exception>        // for std::terminate
+
+//  In general, we treat all pthread errors as fatal - our error
+//  reporting mechanism is std::terminate.
+
+namespace __cxxabiv1 {
+namespace {
+    pthread_once_t flag_ = PTHREAD_ONCE_INIT;
+    pthread_key_t  key_;
+
+    void destruct_ (void *p) throw () {
+        std::free ( p );
+        if ( 0 != ::pthread_setspecific ( key_, NULL )) std::terminate ();
+        }
+
+    void construct_ () throw () {
+        if ( 0 != pthread_key_create ( &key_, destruct_ )) std::terminate ();
+        }
+}   
+
+extern "C" {
+    __cxa_eh_globals * __cxa_get_globals () throw () {
+    //  First time through, create the key.
+        if ( 0 != pthread_once ( &flag_, construct_ )) std::terminate ();
+
+    //  Try to get the globals for this thread
+        __cxa_eh_globals* retVal = __cxa_get_globals_fast ();
+    
+    //  If this is the first time we've been asked for these globals, create them
+        if ( NULL == retVal ) {
+            retVal = static_cast<__cxa_eh_globals*>
+                        (std::calloc (1, sizeof (__cxa_eh_globals)));
+            if ( NULL == retVal ) std::terminate ();
+            if ( 0 != pthread_setspecific ( key_, retVal )) std::terminate ();
+            }
+        return retVal;
+        }
+
+    __cxa_eh_globals * __cxa_get_globals_fast () throw () {
+        return static_cast<__cxa_eh_globals*>(::pthread_getspecific(key_));
+        }
+    
+}
+}
+#endif