Author: ericwf
Date: Tue Jul 11 18:34:21 2017
New Revision: 307748
URL: http://llvm.org/viewvc/llvm-project?rev=307748&view=rev
Log:
Remove dependancy on __refstring header; use local copy instead.
This patch removes the dependancy on libc++'s __refstring header,
which was only a header in the first place so that libc++abi could
build library code using it, and not because libc++ needed it in
the headers.
This patch allows libc++ to stop shipping <__refstring> publicaly
at the cost of duplicating it across projects. Ideally libc++abi
would always require the libc++ sources when building, but that's
a separate discussion I plan to start on the mailing lists shortly.
Added:
libcxxabi/trunk/src/include/
libcxxabi/trunk/src/include/refstring.h
Modified:
libcxxabi/trunk/src/stdlib_stdexcept.cpp
Added: libcxxabi/trunk/src/include/refstring.h
URL:
http://llvm.org/viewvc/llvm-project/libcxxabi/trunk/src/include/refstring.h?rev=307748&view=auto
==============================================================================
--- libcxxabi/trunk/src/include/refstring.h (added)
+++ libcxxabi/trunk/src/include/refstring.h Tue Jul 11 18:34:21 2017
@@ -0,0 +1,131 @@
+//===------------------------ __refstring
---------------------------------===//
+//
+// 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.
+//
+//===----------------------------------------------------------------------===//
+
+// FIXME: This file is copied from libcxx/src/include/refstring.h. Instead of
+// duplicating the file in libc++abi we should require that the libc++ sources
+// are available when building libc++abi.
+
+#ifndef _LIBCPPABI_REFSTRING_H
+#define _LIBCPPABI_REFSTRING_H
+
+#include <__config>
+#include <stdexcept>
+#include <cstddef>
+#include <cstring>
+#ifdef __APPLE__
+#include <dlfcn.h>
+#include <mach-o/dyld.h>
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace __refstring_imp { namespace {
+typedef int count_t;
+
+struct _Rep_base {
+ std::size_t len;
+ std::size_t cap;
+ count_t count;
+};
+
+inline _Rep_base* rep_from_data(const char *data_) noexcept {
+ char *data = const_cast<char *>(data_);
+ return reinterpret_cast<_Rep_base *>(data - sizeof(_Rep_base));
+}
+
+inline char * data_from_rep(_Rep_base *rep) noexcept {
+ char *data = reinterpret_cast<char *>(rep);
+ return data + sizeof(*rep);
+}
+
+#if defined(__APPLE__)
+inline
+const char* compute_gcc_empty_string_storage() _NOEXCEPT
+{
+ void* handle = dlopen("/usr/lib/libstdc++.6.dylib", RTLD_NOLOAD);
+ if (handle == nullptr)
+ return nullptr;
+ void* sym = dlsym(handle, "_ZNSs4_Rep20_S_empty_rep_storageE");
+ if (sym == nullptr)
+ return nullptr;
+ return data_from_rep(reinterpret_cast<_Rep_base *>(sym));
+}
+
+inline
+const char*
+get_gcc_empty_string_storage() _NOEXCEPT
+{
+ static const char* p = compute_gcc_empty_string_storage();
+ return p;
+}
+#endif
+
+}} // namespace __refstring_imp
+
+using namespace __refstring_imp;
+
+inline
+__libcpp_refstring::__libcpp_refstring(const char* msg) {
+ std::size_t len = strlen(msg);
+ _Rep_base* rep = static_cast<_Rep_base *>(::operator new(sizeof(*rep) +
len + 1));
+ rep->len = len;
+ rep->cap = len;
+ rep->count = 0;
+ char *data = data_from_rep(rep);
+ std::memcpy(data, msg, len + 1);
+ __imp_ = data;
+}
+
+inline
+__libcpp_refstring::__libcpp_refstring(const __libcpp_refstring &s) _NOEXCEPT
+ : __imp_(s.__imp_)
+{
+ if (__uses_refcount())
+ __sync_add_and_fetch(&rep_from_data(__imp_)->count, 1);
+}
+
+inline
+__libcpp_refstring& __libcpp_refstring::operator=(__libcpp_refstring const& s)
_NOEXCEPT {
+ bool adjust_old_count = __uses_refcount();
+ struct _Rep_base *old_rep = rep_from_data(__imp_);
+ __imp_ = s.__imp_;
+ if (__uses_refcount())
+ __sync_add_and_fetch(&rep_from_data(__imp_)->count, 1);
+ if (adjust_old_count)
+ {
+ if (__sync_add_and_fetch(&old_rep->count, count_t(-1)) < 0)
+ {
+ ::operator delete(old_rep);
+ }
+ }
+ return *this;
+}
+
+inline
+__libcpp_refstring::~__libcpp_refstring() {
+ if (__uses_refcount()) {
+ _Rep_base* rep = rep_from_data(__imp_);
+ if (__sync_add_and_fetch(&rep->count, count_t(-1)) < 0) {
+ ::operator delete(rep);
+ }
+ }
+}
+
+inline
+bool __libcpp_refstring::__uses_refcount() const {
+#ifdef __APPLE__
+ return __imp_ != get_gcc_empty_string_storage();
+#else
+ return true;
+#endif
+}
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif //_LIBCPPABI_REFSTRING_H
Modified: libcxxabi/trunk/src/stdlib_stdexcept.cpp
URL:
http://llvm.org/viewvc/llvm-project/libcxxabi/trunk/src/stdlib_stdexcept.cpp?rev=307748&r1=307747&r2=307748&view=diff
==============================================================================
--- libcxxabi/trunk/src/stdlib_stdexcept.cpp (original)
+++ libcxxabi/trunk/src/stdlib_stdexcept.cpp Tue Jul 11 18:34:21 2017
@@ -7,7 +7,7 @@
//
//===----------------------------------------------------------------------===//
-#include "__refstring"
+#include "include/refstring.h"
#include "stdexcept"
#include "new"
#include <cstdlib>
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
