[libcxx-commits] [PATCH] D82627: Fix CFI issues in <future>

[Brandon Tolsch via Phabricator via libcxx-commits]

btolsch updated this revision to Diff 281653.
btolsch added a comment.

I changed the patch to be more annotation-oriented while trying to avoid just tacking _LIBCPP_NO_CFI onto every function.  PTAL, thanks!


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D82627/new/

https://reviews.llvm.org/D82627

Files:
  libcxx/include/future


Index: libcxx/include/future
===================================================================
--- libcxx/include/future
+++ libcxx/include/future
@@ -1823,6 +1823,9 @@
 class _LIBCPP_AVAILABILITY_FUTURE __packaged_task_function<_Rp(_ArgTypes...)>
 {
     typedef __packaged_task_base<_Rp(_ArgTypes...)> __base;
+
+    _LIBCPP_NO_CFI __base* buf_() { return (__base*)&__buf_; }
+
     typename aligned_storage<3*sizeof(void*)>::type __buf_;
     __base* __f_;
 
@@ -1856,10 +1859,10 @@
 {
     if (__f.__f_ == nullptr)
         __f_ = nullptr;
-    else if (__f.__f_ == (__base*)&__f.__buf_)
+    else if (__f.__f_ == __f.buf_())
     {
+        __f.__f_->__move_to(buf_());
         __f_ = (__base*)&__buf_;
-        __f.__f_->__move_to(__f_);
     }
     else
     {
@@ -1877,8 +1880,8 @@
     typedef __packaged_task_func<_FR, allocator<_FR>, _Rp(_ArgTypes...)> _FF;
     if (sizeof(_FF) <= sizeof(__buf_))
     {
+        ::new (&__buf_) _FF(_VSTD::forward<_Fp>(__f));
         __f_ = (__base*)&__buf_;
-        ::new (__f_) _FF(_VSTD::forward<_Fp>(__f));
     }
     else
     {
@@ -1920,17 +1923,17 @@
 __packaged_task_function<_Rp(_ArgTypes...)>&
 __packaged_task_function<_Rp(_ArgTypes...)>::operator=(__packaged_task_function&& __f) _NOEXCEPT
 {
-    if (__f_ == (__base*)&__buf_)
+    if (__f_ == buf_())
         __f_->destroy();
     else if (__f_)
         __f_->destroy_deallocate();
     __f_ = nullptr;
     if (__f.__f_ == nullptr)
         __f_ = nullptr;
-    else if (__f.__f_ == (__base*)&__f.__buf_)
+    else if (__f.__f_ == __f.buf_())
     {
+        __f.__f_->__move_to(buf_());
         __f_ = (__base*)&__buf_;
-        __f.__f_->__move_to(__f_);
     }
     else
     {
@@ -1943,13 +1946,14 @@
 template<class _Rp, class ..._ArgTypes>
 __packaged_task_function<_Rp(_ArgTypes...)>::~__packaged_task_function()
 {
-    if (__f_ == (__base*)&__buf_)
+    if (__f_ == buf_())
         __f_->destroy();
     else if (__f_)
         __f_->destroy_deallocate();
 }
 
 template<class _Rp, class ..._ArgTypes>
+_LIBCPP_NO_CFI
 void
 __packaged_task_function<_Rp(_ArgTypes...)>::swap(__packaged_task_function& __f) _NOEXCEPT
 {


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