Merge pull request #4827 from ziglang/zig-cpp

support compiling and linking c++ code

1 files changed, 105 insertions, 0 deletions

diff --git a/lib/libcxxabi/src/cxa_exception_storage.cpp b/lib/libcxxabi/src/cxa_exception_storage.cpp
new file mode 100644
index 0000000000..24ff55e39d
--- /dev/null
+++ b/lib/libcxxabi/src/cxa_exception_storage.cpp
@@ -0,0 +1,105 @@
+//===--------------------- cxa_exception_storage.cpp ----------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//
+//  This file implements the storage for the "Caught Exception Stack"
+//  https://itanium-cxx-abi.github.io/cxx-abi/abi-eh.html#cxx-exc-stack
+//
+//===----------------------------------------------------------------------===//
+
+#include "cxa_exception.h"
+
+#include <__threading_support>
+
+#if defined(_LIBCXXABI_HAS_NO_THREADS)
+
+namespace __cxxabiv1 {
+extern "C" {
+    static __cxa_eh_globals eh_globals;
+    __cxa_eh_globals *__cxa_get_globals() { return &eh_globals; }
+    __cxa_eh_globals *__cxa_get_globals_fast() { return &eh_globals; }
+    }
+}
+
+#elif defined(HAS_THREAD_LOCAL)
+
+namespace __cxxabiv1 {
+
+namespace {
+    __cxa_eh_globals * __globals () {
+        static thread_local __cxa_eh_globals eh_globals;
+        return &eh_globals;
+        }
+    }
+
+extern "C" {
+    __cxa_eh_globals * __cxa_get_globals      () { return __globals (); }
+    __cxa_eh_globals * __cxa_get_globals_fast () { return __globals (); }
+    }
+}
+
+#else
+
+#include "abort_message.h"
+#include "fallback_malloc.h"
+
+#if defined(__ELF__) && defined(_LIBCXXABI_LINK_PTHREAD_LIB)
+#pragma comment(lib, "pthread")
+#endif
+
+//  In general, we treat all threading errors as fatal.
+//  We cannot call std::terminate() because that will in turn
+//  call __cxa_get_globals() and cause infinite recursion.
+
+namespace __cxxabiv1 {
+namespace {
+    std::__libcpp_tls_key key_;
+    std::__libcpp_exec_once_flag flag_ = _LIBCPP_EXEC_ONCE_INITIALIZER;
+
+    void _LIBCPP_TLS_DESTRUCTOR_CC destruct_ (void *p) {
+        __free_with_fallback ( p );
+        if ( 0 != std::__libcpp_tls_set ( key_, NULL ) )
+            abort_message("cannot zero out thread value for __cxa_get_globals()");
+        }
+
+    void construct_ () {
+        if ( 0 != std::__libcpp_tls_create ( &key_, destruct_ ) )
+            abort_message("cannot create thread specific key for __cxa_get_globals()");
+        }
+}
+
+extern "C" {
+    __cxa_eh_globals * __cxa_get_globals () {
+    //  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*>
+                        (__calloc_with_fallback (1, sizeof (__cxa_eh_globals)));
+            if ( NULL == retVal )
+                abort_message("cannot allocate __cxa_eh_globals");
+            if ( 0 != std::__libcpp_tls_set ( key_, retVal ) )
+               abort_message("std::__libcpp_tls_set failure in __cxa_get_globals()");
+           }
+        return retVal;
+        }
+
+    // Note that this implementation will reliably return NULL if not
+    // preceded by a call to __cxa_get_globals().  This is an extension
+    // to the Itanium ABI and is taken advantage of in several places in
+    // libc++abi.
+    __cxa_eh_globals * __cxa_get_globals_fast () {
+    //  First time through, create the key.
+        if (0 != std::__libcpp_execute_once(&flag_, construct_))
+            abort_message("execute once failure in __cxa_get_globals_fast()");
+//        static int init = construct_();
+        return static_cast<__cxa_eh_globals*>(std::__libcpp_tls_get(key_));
+        }
+
+}
+}
+#endif