Libraries: Move to Userland/Libraries/

1 files changed, 89 insertions, 0 deletions

diff --git a/Userland/Libraries/LibC/cxxabi.cpp b/Userland/Libraries/LibC/cxxabi.cpp
new file mode 100644
index 0000000000..05978bfe9b
--- /dev/null
+++ b/Userland/Libraries/LibC/cxxabi.cpp
@@ -0,0 +1,89 @@
+/*
+ * Copyright (c) 2019-2020, Andrew Kaster <andrewdkaster@gmail.com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/internals.h>
+
+//#define GLOBAL_DTORS_DEBUG
+
+extern "C" {
+
+struct __exit_entry {
+    AtExitFunction method;
+    void* parameter;
+    void* dso_handle;
+    bool has_been_called;
+};
+
+static __exit_entry __exit_entries[1024] {};
+static int __exit_entry_count = 0;
+
+int __cxa_atexit(AtExitFunction exit_function, void* parameter, void* dso_handle)
+{
+    if (__exit_entry_count >= 1024)
+        return -1;
+
+    __exit_entries[__exit_entry_count++] = { exit_function, parameter, dso_handle, false };
+
+    return 0;
+}
+
+void __cxa_finalize(void* dso_handle)
+{
+    // From the itanium abi, https://itanium-cxx-abi.github.io/cxx-abi/abi.html#dso-dtor-runtime-api
+    //
+    // When __cxa_finalize(d) is called, it should walk the termination function list, calling each in turn
+    // if d matches __dso_handle for the termination function entry. If d == NULL, it should call all of them.
+    // Multiple calls to __cxa_finalize shall not result in calling termination function entries multiple times;
+    // the implementation may either remove entries or mark them finished.
+
+    int entry_index = __exit_entry_count;
+
+#ifdef GLOBAL_DTORS_DEBUG
+    dbgprintf("__cxa_finalize: %d entries in the finalizer list\n", entry_index);
+#endif
+
+    while (--entry_index >= 0) {
+        auto& exit_entry = __exit_entries[entry_index];
+        bool needs_calling = !exit_entry.has_been_called && (!dso_handle || dso_handle == exit_entry.dso_handle);
+        if (needs_calling) {
+#ifdef GLOBAL_DTORS_DEBUG
+            dbgprintf("__cxa_finalize: calling entry[%d] %p(%p) dso: %p\n", entry_index, exit_entry.method, exit_entry.parameter, exit_entry.dso_handle);
+#endif
+            exit_entry.method(exit_entry.parameter);
+            exit_entry.has_been_called = true;
+        }
+    }
+}
+
+[[noreturn]] void __cxa_pure_virtual()
+{
+    ASSERT_NOT_REACHED();
+}
+
+} // extern "C"