diff options
| -rw-r--r-- | gcc/testsuite/ChangeLog | 4 | ||||
| -rw-r--r-- | gcc/testsuite/g++.dg/rtti/dyncast3.C | 81 | ||||
| -rw-r--r-- | gcc/testsuite/g++.dg/rtti/dyncast4.C | 26 | ||||
| -rw-r--r-- | libstdc++-v3/ChangeLog | 5 | ||||
| -rw-r--r-- | libstdc++-v3/libsupc++/dyncast.cc | 16 | ||||
| -rw-r--r-- | libstdc++-v3/libsupc++/vmi_class_type_info.cc | 32 |
6 files changed, 163 insertions, 1 deletions
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 81ed85c..3a97503 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,7 @@ +2009-07-06 Jason Merrill <jason@redhat.com> + + * g++.dg/rtti/dyncast[34].C: New. + 2009-07-06 Nathan Froyd <froydnj@codesourcery.com> * lib/target-supports.exp diff --git a/gcc/testsuite/g++.dg/rtti/dyncast3.C b/gcc/testsuite/g++.dg/rtti/dyncast3.C new file mode 100644 index 0000000..0835259 --- /dev/null +++ b/gcc/testsuite/g++.dg/rtti/dyncast3.C @@ -0,0 +1,81 @@ +// This testcase used to crash while looking in A for my_module. I'm still +// not sure it's well-formed, but it works now because of the optimization +// to look at the expected address first. + +// { dg-do run } + +extern "C" int puts (const char *); +extern "C" void abort (); + +struct my_object +{ + my_object() { puts ("in my_object ctor");} + virtual ~my_object() { puts ("in my_object dtor"); } +}; + +my_object* my_module_ptr = 0; + +struct my_module : my_object +{ + my_module() + { + puts ("in my_module ctor, setting up ptr"); + my_module_ptr = this; + } + ~my_module() { puts ("in my_module dtor");} +}; + +struct D +{ + D() { puts ("in D ctor"); } + virtual ~D(); +}; + +D::~D() +{ + puts ("in D dtor"); + puts ("before DCASTing to my_module*"); + my_module* m = dynamic_cast<my_module*>(my_module_ptr); + if (m != my_module_ptr) + abort (); + puts ("after DCASTing to my_module*"); +} + +struct my_interface +{ + my_interface() { puts ("in my_interface ctor");} + ~my_interface() { puts ("in my_interface dtor");} +}; + +struct myif : virtual my_interface +{ + myif() { puts ("in myif ctor");} + ~myif() { puts ("in myif dtor");} +}; + +struct A: virtual myif +{ + A() { puts ("in A ctor"); } + ~A() { puts ("in A dtor"); } + + D d; +}; + +struct B: virtual myif +{ + B() { puts ("in B ctor"); } + ~B() { puts ("in B dtor"); } + + D d; +}; + +struct C : my_module, A, B +{ + C() { puts ("in C ctor");} + ~C() { puts ("in C dtor"); } +}; + +int main(int, char**) +{ + C t; +} diff --git a/gcc/testsuite/g++.dg/rtti/dyncast4.C b/gcc/testsuite/g++.dg/rtti/dyncast4.C new file mode 100644 index 0000000..2a5fd2b --- /dev/null +++ b/gcc/testsuite/g++.dg/rtti/dyncast4.C @@ -0,0 +1,26 @@ +// Test to make sure that we keep searching if we don't find the type we +// want at the expected address. + +// { dg-do run } + +struct A +{ + virtual void f() {}; +}; + +struct B: A { }; + +struct C: A { }; + +struct D: B, C { }; + +int main() +{ + D d; + A* ap = static_cast<B*>(&d); + C* cp = dynamic_cast<C*>(ap); + if (cp == 0) + return 1; + else + return 0; +} diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog index a6db9d0..aaf7921 100644 --- a/libstdc++-v3/ChangeLog +++ b/libstdc++-v3/ChangeLog @@ -1,3 +1,8 @@ +2009-07-06 Jason Merrill <jason@redhat.com> + + * libsupc++/vmi_class_type_info.cc (__do_dyncast): Use src2dst hint + to defer searching bases that don't overlap the desired address. + 2009-07-05 Joseph Myers <joseph@codesourcery.com> * diff --git a/libstdc++-v3/libsupc++/dyncast.cc b/libstdc++-v3/libsupc++/dyncast.cc index f565ed4..cb97bc5 100644 --- a/libstdc++-v3/libsupc++/dyncast.cc +++ b/libstdc++-v3/libsupc++/dyncast.cc @@ -28,12 +28,26 @@ namespace __cxxabiv1 { // this is the external interface to the dynamic cast machinery +/* sub: source address to be adjusted; nonnull, and since the + * source object is polymorphic, *(void**)sub is a virtual pointer. + * src: static type of the source object. + * dst: destination type (the "T" in "dynamic_cast<T>(v)"). + * src2dst_offset: a static hint about the location of the + * source subobject with respect to the complete object; + * special negative values are: + * -1: no hint + * -2: src is not a public base of dst + * -3: src is a multiple public base type but never a + * virtual base type + * otherwise, the src type is a unique public nonvirtual + * base type of dst at offset src2dst_offset from the + * origin of dst. */ extern "C" void * __dynamic_cast (const void *src_ptr, // object started from const __class_type_info *src_type, // type of the starting object const __class_type_info *dst_type, // desired target type ptrdiff_t src2dst) // how src and dst are related -{ + { const void *vtable = *static_cast <const void *const *> (src_ptr); const vtable_prefix *prefix = adjust_pointer <vtable_prefix> (vtable, diff --git a/libstdc++-v3/libsupc++/vmi_class_type_info.cc b/libstdc++-v3/libsupc++/vmi_class_type_info.cc index 6904f77..195061d 100644 --- a/libstdc++-v3/libsupc++/vmi_class_type_info.cc +++ b/libstdc++-v3/libsupc++/vmi_class_type_info.cc @@ -108,7 +108,17 @@ __do_dyncast (ptrdiff_t src2dst, return false; } + // If src_type is a unique non-virtual base of dst_type, we have a good + // guess at the address we want, so in the first pass try skipping any + // bases which don't contain that address. + const void *dst_cand = NULL; + if (src2dst >= 0) + dst_cand = adjust_pointer<void>(src_ptr, -src2dst); + bool first_pass = true; + bool skipped = false; + bool result_ambig = false; + again: for (std::size_t i = __base_count; i--;) { __dyncast_result result2 (result.whole_details); @@ -121,6 +131,20 @@ __do_dyncast (ptrdiff_t src2dst, base_access = __sub_kind (base_access | __contained_virtual_mask); base = convert_to_base (base, is_virtual, offset); + if (dst_cand) + { + bool skip_on_first_pass = base > dst_cand; + if (skip_on_first_pass == first_pass) + { + // We aren't interested in this base on this pass: either + // we're on the first pass and this base doesn't contain the + // likely address, or we're on the second pass and we checked + // this base on the first pass. + skipped = true; + continue; + } + } + if (!__base_info[i].__is_public_p ()) { if (src2dst == -2 && @@ -267,6 +291,14 @@ __do_dyncast (ptrdiff_t src2dst, return result_ambig; } + if (skipped && first_pass) + { + // We didn't find dst where we expected it, so let's go back and try + // the bases we skipped (if any). + first_pass = false; + goto again; + } + return result_ambig; } |