[Bug c++/103303] New: compiler have trouble to point to the correct destructor address while for large align objects with complex inheritance while destruct object

[Bug c++/103303] New: compiler have trouble to point to the correct destructor address while for large align objects with complex inheritance while destruct object

[wqpfelix at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103303

            Bug ID: 103303
           Summary: compiler have trouble to point to the correct
                    destructor address while for large align objects with
                    complex inheritance while destruct object
           Product: gcc
           Version: 8.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: wqpfelix at gmail dot com
  Target Milestone: ---

Created attachment 51825
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=51825&action=edit
c++ code trigger the 0x8 offset for movaps

the error is reproduced on compiler explorer:
https://godbolt.org/z/v8roq3641
where I can trigger this problem while gcc after 8.1

more details: 
while running with the following compiler
```sh
$Compiler/bin/g++ -v
Using built-in specs.
COLLECT_GCC=/net/binlib/build-kits/build-kit-20191029-x86_64-pc-linux-gnu-gcc-8.2.0-gcc82_u18_v3/bin/g++
COLLECT_LTO_WRAPPER=/net/binlib/build-kits/build-kit-20191029-x86_64-pc-linux-gnu-gcc-8.2.0-gcc82_u18_v3/bin/../libexec/gcc/x86_64-pc-linux-gnu/8.2.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: .../gcc/configure --with-gmp={PathTo_gcc82_u18_v3}
--with-mpfr={PathTo_gcc82_u18_v3} --with-mpc={PathTo_gcc82_u18_v3}
--with-isl={PathTo_gcc82_u18_v3} --prefix={PathTo_gcc82_u18_v3}
--exec-prefix={PathTo_gcc82_u18_v3} --enable-languages=c,c++ --enable-shared
--enable-static --enable-threads=posix --disable-host-shared --enable-lto
--with-ld={PathTo_gcc82_u18_v3}/bin/ld --target=x86_64-pc-linux-gnu
--with-sysroot=/.
--with-gxx-include-dir={PathTo_gcc82_u18_v3}/include/libstdc++
--disable-multilib --verbose
Thread model: posix
gcc version 8.2.0 (GCC)
```

on C++ program with
```C++
#include <iostream>
#include <cstddef>

struct alignas(16) largeAligned{ // change to 8, no crash
    uint32_t u_arr[128];
};

template<typename Base>
struct ICategory: public virtual Base{
    ICategory(){
        std::cout << __PRETTY_FUNCTION__ << std::endl;
    }
};

struct PureInterfaceHandler{
    virtual ~PureInterfaceHandler() = default;
};

template<typename...MsgCategoryNotifierS>
class TemplateNotifier
          : public PureInterfaceHandler,
             public MsgCategoryNotifierS...{
public:
    TemplateNotifier() {
        std::cout << __PRETTY_FUNCTION__  << std::endl;
    }

    virtual ~TemplateNotifier() {
        std::cout << __PRETTY_FUNCTION__  << std::endl;
    }
};


struct Base1{
    Base1(){
        std::cout << __PRETTY_FUNCTION__  << std::endl;
    }
    virtual ~Base1(){
        std::cout << __PRETTY_FUNCTION__  << std::endl;
    }
    largeAligned aligned1;
};


struct Base2{
    Base2(){
        std::cout << __PRETTY_FUNCTION__  << std::endl;
    }
    virtual ~Base2(){
        std::cout << __PRETTY_FUNCTION__  << std::endl;
    }
    largeAligned aligned2;
};

using Category2 = ICategory<Base1>;
using Category1 = ICategory<Base2>;
struct ProblematicNotifier: TemplateNotifier<Category1, Category2>{};

int main(){
    static_assert(alignof(ProblematicNotifier) == 16, "128 is great" );
    static_assert( alignof(std::max_align_t) == 16, "16? is great" );
    ProblematicNotifier* objPtr = new ProblematicNotifier();
    delete objPtr;
    std::cout << "Done" << std::endl;
}
```


with: 
    $Compiler/bin/g++ -I $Compiler/include -I $Compiler/include/libstdc++
crash.cpp -O3
I found: 
    Program received signal SIGSEGV, Segmentation fault.
    0x000000000040228a in ProblematicNotifier::~ProblematicNotifier() ()
on instruction: 
    0x40228a <_ZN19ProblematicNotifierD0Ev+202>     movaps %xmm0,0x8(%rbx)
where (gdb) x/i $rbx
      0x417e70:    mov    $0x34,%al

it looks like compiler generates 
movaps with offset 0x8 while handling aligned object, while is not expected for
movaps

[Bug c++/103303] compiler have trouble to point to the correct destructor address while for large align objects with complex inheritance while destructing object

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103303

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |wrong-code

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---

#include <iostream>
#include <cstddef>

struct alignas(16) largeAligned{ // change to 8, no crash
    uint32_t u_arr[128];
};

template<typename Base>
struct ICategory: public virtual Base{
    ICategory(){
        std::cout << __PRETTY_FUNCTION__ << std::endl;
    }
};

struct PureInterfaceHandler{
    virtual ~PureInterfaceHandler() = default;
};

template<typename...MsgCategoryNotifierS>
class TemplateNotifier
          : public PureInterfaceHandler,
             public MsgCategoryNotifierS...{
public:
    TemplateNotifier() {
        std::cout << __PRETTY_FUNCTION__  << std::endl;
    }

    virtual ~TemplateNotifier() {
        std::uintptr_t t = (std::uintptr_t)this;
        printf("this:%lx\n", (long)(t&0xff));
        printf("this->PureInterfaceHandler:%lx\n",
(long)((std::uintptr_t)(PureInterfaceHandler*)this&0xff));
        (printf("this->%s:%lx\n", typeid
(MsgCategoryNotifierS).name(),(long)((std::uintptr_t)(MsgCategoryNotifierS*)this&0xff)),...);
        std::cout << __PRETTY_FUNCTION__  << std::endl;
    }
};


struct Base1{
    Base1(){
        std::cout << __PRETTY_FUNCTION__  << std::endl;
        std::uintptr_t t = (std::uintptr_t)&aligned1;
        printf("%lx\n", (long)(t&0xff));
    }
    virtual ~Base1(){
        std::uintptr_t t = (std::uintptr_t)&aligned1;
        printf("%lx\n", (long)(t&0xff));
        std::cout << __PRETTY_FUNCTION__  << std::endl;
    }
    largeAligned aligned1;
};


struct Base2{
    Base2(){
        std::cout << __PRETTY_FUNCTION__  << std::endl;
        std::uintptr_t t = (std::uintptr_t)&aligned2;
        printf("%lx\n", (long)(t&0xff));
    }
    virtual ~Base2(){
        std::uintptr_t t = (std::uintptr_t)&aligned2;
        printf("%lx\n", (long)(t&0xff));
        std::cout << __PRETTY_FUNCTION__  << std::endl;
    }
    largeAligned aligned2;
};

using Category2 = ICategory<Base1>;
using Category1 = ICategory<Base2>;
struct ProblematicNotifier: TemplateNotifier<Category1, Category2>{};

int main(){
    static_assert(alignof(ProblematicNotifier) == 16, "128 is great" );
    static_assert( alignof(std::max_align_t) == 16, "16? is great" );
    ProblematicNotifier* objPtr = new ProblematicNotifier();
    delete objPtr;
    std::cout << "Done" << std::endl;
}

Looks like there is some wrong alignment information feed to the rest of the
compiler.
this->9ICategoryI5Base2E:b8
this->9ICategoryI5Base1E:c0

[Bug c++/103303] compiler have trouble to point to the correct destructor address while for large align objects with complex inheritance while destructing object

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103303

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to fail|                            |11.2.0, 8.2.0
            Version|8.2.0                       |11.2.0
                 CC|                            |jason at gcc dot gnu.org
           Keywords|                            |ABI

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
Maybe an issue in the C++ layout engine.

[Bug c++/103303] compiler have trouble to point to the correct destructor address while for large align objects with complex inheritance while destructing object

[wqpfelix at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103303

--- Comment #3 from Felix Wang <wqpfelix at gmail dot com> ---
Could I assume this is a compiler bug in layout engine?