[libcxxabi] r236862 - Merging r233984:

[Tom Stellard]

Author: tstellar
Date: Fri May  8 10:10:43 2015
New Revision: 236862

URL: http://llvm.org/viewvc/llvm-project?rev=236862&view=rev
Log:
Merging r233984:
------------------------------------------------------------------------
r233984 | ericwf | 2015-04-02 16:26:37 -0700 (Thu, 02 Apr 2015) | 22 lines

[libcxxabi] Fix multi-level pointer conversions and pointer to member conversion detection.

Summary:
Currently there are bugs in out detection of multi-level pointer conversions and pointer to member conversions. This patch fixes the following issues.

* Allow multi-level pointers with different nested qualifiers.
* Allow multi-level mixed pointers to objects and pointers to members with different nested qualifiers.
* Allow conversions from `int Base::*` to `int Derived::*` but only for non-nested pointers.

There is still some work that needs to be done to clean this patch up but I want to get some input on it.
Open questions:

* Does `__pointer_to_member_type_info::can_catch(...)` need to adjust the pointer if a base to derived conversion is performed?


Reviewers: danalbert, compnerd, mclow.lists

Reviewed By: mclow.lists

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D8758
------------------------------------------------------------------------

Added:
    libcxxabi/branches/release_36/test/catch_multi_level_pointer.pass.cpp
      - copied unchanged from r233984, libcxxabi/trunk/test/catch_multi_level_pointer.pass.cpp
Modified:
    libcxxabi/branches/release_36/   (props changed)
    libcxxabi/branches/release_36/src/private_typeinfo.cpp
    libcxxabi/branches/release_36/src/private_typeinfo.h

Propchange: libcxxabi/branches/release_36/
------------------------------------------------------------------------------
--- svn:mergeinfo (original)
+++ svn:mergeinfo Fri May  8 10:10:43 2015
@@ -1 +1 @@
-/libcxxabi/trunk:226818-226820,226822-226824,228359,231839,231852
+/libcxxabi/trunk:226818-226820,226822-226824,228359,231839,231852,233984

Modified: libcxxabi/branches/release_36/src/private_typeinfo.cpp
URL: http://llvm.org/viewvc/llvm-project/libcxxabi/branches/release_36/src/private_typeinfo.cpp?rev=236862&r1=236861&r2=236862&view=diff
==============================================================================
--- libcxxabi/branches/release_36/src/private_typeinfo.cpp (original)
+++ libcxxabi/branches/release_36/src/private_typeinfo.cpp Fri May  8 10:10:43 2015
@@ -383,6 +383,24 @@ __pointer_type_info::can_catch(const __s
     // bullet 3A
     if (is_equal(__pointee, &typeid(void), false))
         return true;
+
+    // Handle pointer to pointer
+    const __pointer_type_info* nested_pointer_type =
+        dynamic_cast<const __pointer_type_info*>(__pointee);
+    if (nested_pointer_type) {
+        if (~__flags & __const_mask) return false;
+        return nested_pointer_type->can_catch_nested(thrown_pointer_type->__pointee);
+    }
+
+    // Handle pointer to pointer to member
+    const __pointer_to_member_type_info* member_ptr_type =
+        dynamic_cast<const __pointer_to_member_type_info*>(__pointee);
+    if (member_ptr_type) {
+        if (~__flags & __const_mask) return false;
+        return member_ptr_type->can_catch_nested(thrown_pointer_type->__pointee);
+    }
+
+    // Handle pointer to class type
     const __class_type_info* catch_class_type =
         dynamic_cast<const __class_type_info*>(__pointee);
     if (catch_class_type == 0)
@@ -403,6 +421,84 @@ __pointer_type_info::can_catch(const __s
     return false;
 }
 
+bool __pointer_type_info::can_catch_nested(
+    const __shim_type_info* thrown_type) const
+{
+  const __pointer_type_info* thrown_pointer_type =
+        dynamic_cast<const __pointer_type_info*>(thrown_type);
+    if (thrown_pointer_type == 0)
+        return false;
+    // bullet 3B
+    if (thrown_pointer_type->__flags & ~__flags)
+        return false;
+    if (is_equal(__pointee, thrown_pointer_type->__pointee, false))
+        return true;
+    // If the pointed to types differ then the catch type must be const
+    // qualified.
+    if (~__flags & __const_mask)
+        return false;
+
+    // Handle pointer to pointer
+    const __pointer_type_info* nested_pointer_type =
+        dynamic_cast<const __pointer_type_info*>(__pointee);
+    if (nested_pointer_type) {
+        return nested_pointer_type->can_catch_nested(
+            thrown_pointer_type->__pointee);
+    }
+
+    // Handle pointer to pointer to member
+    const __pointer_to_member_type_info* member_ptr_type =
+        dynamic_cast<const __pointer_to_member_type_info*>(__pointee);
+    if (member_ptr_type) {
+        return member_ptr_type->can_catch_nested(thrown_pointer_type->__pointee);
+    }
+
+    return false;
+}
+
+bool __pointer_to_member_type_info::can_catch(
+    const __shim_type_info* thrown_type, void*& adjustedPtr) const {
+    // bullets 1 and 4
+    if (__pbase_type_info::can_catch(thrown_type, adjustedPtr))
+        return true;
+
+    const __pointer_to_member_type_info* thrown_pointer_type =
+        dynamic_cast<const __pointer_to_member_type_info*>(thrown_type);
+    if (thrown_pointer_type == 0)
+        return false;
+    if (thrown_pointer_type->__flags & ~__flags)
+        return false;
+    if (!is_equal(__pointee, thrown_pointer_type->__pointee, false))
+        return false;
+    if (is_equal(__context, thrown_pointer_type->__context, false))
+        return true;
+
+    __dynamic_cast_info info = {__context, 0, thrown_pointer_type->__context, -1, 0};
+    info.number_of_dst_type = 1;
+    __context->has_unambiguous_public_base(&info, adjustedPtr, public_path);
+    if (info.path_dst_ptr_to_static_ptr == public_path)
+        return true;
+
+    return false;
+}
+
+bool __pointer_to_member_type_info::can_catch_nested(
+    const __shim_type_info* thrown_type) const
+{
+    const __pointer_to_member_type_info* thrown_member_ptr_type =
+        dynamic_cast<const __pointer_to_member_type_info*>(thrown_type);
+    if (thrown_member_ptr_type == 0)
+        return false;
+    if (~__flags & thrown_member_ptr_type->__flags)
+        return false;
+    if (!is_equal(__pointee, thrown_member_ptr_type->__pointee, false))
+        return false;
+    if (!is_equal(__context, thrown_member_ptr_type->__context, false))
+        return false;
+    return true;
+}
+
+#ifdef __clang__
 #pragma clang diagnostic pop
 
 #pragma GCC visibility pop

Modified: libcxxabi/branches/release_36/src/private_typeinfo.h
URL: http://llvm.org/viewvc/llvm-project/libcxxabi/branches/release_36/src/private_typeinfo.h?rev=236862&r1=236861&r2=236862&view=diff
==============================================================================
--- libcxxabi/branches/release_36/src/private_typeinfo.h (original)
+++ libcxxabi/branches/release_36/src/private_typeinfo.h Fri May  8 10:10:43 2015
@@ -230,6 +230,7 @@ class __attribute__ ((__visibility__("de
 public:
     __attribute__ ((__visibility__("hidden"))) virtual ~__pointer_type_info();
     __attribute__ ((__visibility__("hidden"))) virtual bool can_catch(const __shim_type_info*, void*&) const;
+    __attribute__ ((__visibility__("hidden"))) bool can_catch_nested(const __shim_type_info*) const;
 };
 
 class __attribute__ ((__visibility__("default"))) __pointer_to_member_type_info
@@ -239,6 +240,8 @@ public:
     const __class_type_info* __context;
 
     __attribute__ ((__visibility__("hidden"))) virtual ~__pointer_to_member_type_info();
+    __attribute__ ((__visibility__("hidden"))) virtual bool can_catch(const __shim_type_info*, void*&) const;
+    __attribute__ ((__visibility__("hidden"))) bool can_catch_nested(const __shim_type_info*) const;
 };
 
 #pragma GCC visibility pop