[Bug c++/102878] New: Internal compiler error with coroutine calling constexpr function

[lcw at fb dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102878

            Bug ID: 102878
           Summary: Internal compiler error with coroutine calling
                    constexpr function
           Product: gcc
           Version: 10.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: lcw at fb dot com
  Target Milestone: ---

Created attachment 51643
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=51643&action=edit
Preprocessed sources

Here is the full command I'm running, with its complete output:

$ g++-10 -v -save-temps -O2 repro.cc -std=c++20 -fcoroutines
Using built-in specs.
COLLECT_GCC=g++-10
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/10/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none:amdgcn-amdhsa:hsa
OFFLOAD_TARGET_DEFAULT=1
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu
10.3.0-1ubuntu1~20.04' --with-bugurl=file:///usr/share/doc/gcc-10/README.Bugs
--enable-languages=c,ada,c++,go,brig,d,fortran,objc,obj-c++,m2 --prefix=/usr
--with-gcc-major-version-only --program-suffix=-10
--program-prefix=x86_64-linux-gnu- --enable-shared --enable-linker-build-id
--libexecdir=/usr/lib --without-included-gettext --enable-threads=posix
--libdir=/usr/lib --enable-nls --enable-bootstrap --enable-clocale=gnu
--enable-libstdcxx-debug --enable-libstdcxx-time=yes
--with-default-libstdcxx-abi=new --enable-gnu-unique-object
--disable-vtable-verify --enable-plugin --enable-default-pie --with-system-zlib
--enable-libphobos-checking=release --with-target-system-zlib=auto
--enable-objc-gc=auto --enable-multiarch --disable-werror --with-arch-32=i686
--with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib
--with-tune=generic
--enable-offload-targets=nvptx-none=/build/gcc-10-S4I5Pr/gcc-10-10.3.0/debian/tmp-nvptx/usr,amdgcn-amdhsa=/build/gcc-10-S4I5Pr/gcc-10-10.3.0/debian/tmp-gcn/usr,hsa
--without-cuda-driver --enable-checking=release --build=x86_64-linux-gnu
--host=x86_64-linux-gnu --target=x86_64-linux-gnu
--with-build-config=bootstrap-lto-lean --enable-link-mutex
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 10.3.0 (Ubuntu 10.3.0-1ubuntu1~20.04)
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-O2' '-std=c++2a' '-fcoroutines'
'-shared-libgcc' '-mtune=generic' '-march=x86-64'
 /usr/lib/gcc/x86_64-linux-gnu/10/cc1plus -E -quiet -v -imultiarch
x86_64-linux-gnu -D_GNU_SOURCE repro.cc -mtune=generic -march=x86-64 -std=c++2a
-fcoroutines -O2 -fpch-preprocess -fasynchronous-unwind-tables
-fstack-protector-strong -Wformat -Wformat-security -fstack-clash-protection
-fcf-protection -o repro.ii
ignoring duplicate directory "/usr/include/x86_64-linux-gnu/c++/10"
ignoring nonexistent directory "/usr/local/include/x86_64-linux-gnu"
ignoring nonexistent directory "/usr/lib/gcc/x86_64-linux-gnu/10/include-fixed"
ignoring nonexistent directory
"/usr/lib/gcc/x86_64-linux-gnu/10/../../../../x86_64-linux-gnu/include"
#include "..." search starts here:
#include <...> search starts here:
 /public/apps/NCCL/2.8.3-1/include
 /usr/include/c++/10
 /usr/include/x86_64-linux-gnu/c++/10
 /usr/include/c++/10/backward
 /usr/lib/gcc/x86_64-linux-gnu/10/include
 /usr/local/include
 /usr/include/x86_64-linux-gnu
 /usr/include
End of search list.
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-O2' '-std=c++2a' '-fcoroutines'
'-shared-libgcc' '-mtune=generic' '-march=x86-64'
 /usr/lib/gcc/x86_64-linux-gnu/10/cc1plus -fpreprocessed repro.ii -quiet
-dumpbase repro.cc -mtune=generic -march=x86-64 -auxbase repro -O2 -std=c++2a
-version -fcoroutines -fasynchronous-unwind-tables -fstack-protector-strong
-Wformat -Wformat-security -fstack-clash-protection -fcf-protection -o repro.s
GNU C++17 (Ubuntu 10.3.0-1ubuntu1~20.04) version 10.3.0 (x86_64-linux-gnu)
        compiled by GNU C version 10.3.0, GMP version 6.2.0, MPFR version
4.0.2, MPC version 1.1.0, isl version isl-0.22.1-GMP

GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
GNU C++17 (Ubuntu 10.3.0-1ubuntu1~20.04) version 10.3.0 (x86_64-linux-gnu)
        compiled by GNU C version 10.3.0, GMP version 6.2.0, MPFR version
4.0.2, MPC version 1.1.0, isl version isl-0.22.1-GMP

GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: 169ee3a1708a329c07eaf03cc8dfbe6c
repro.cc: In function ‘void
MyClass::doSth()::<lambda()>::_ZZN7MyClass5doSthEvENKUlvE_clEv.actor(MyClass::doSth()::<lambda()>::_ZZN7MyClass5doSthEvENKUlvE_clEv.frame*)’:
repro.cc:42:3: internal compiler error: in is_this_parameter, at
cp/semantics.c:10206
   42 |   }();
      |   ^
Please submit a full bug report,
with preprocessed source if appropriate.
See <file:///usr/share/doc/gcc-10/README.Bugs> for instructions.



The original C++ repro:

#include <coroutine>

class Task : public std::suspend_never {
 private:
  class Promise {
   public:
    Task get_return_object() {
      return Task();
    }

    std::suspend_never initial_suspend() {
      return {};
    }

    std::suspend_never final_suspend() noexcept {
      return {};
    }

    void return_void() {}

    void unhandled_exception() {}
  };

 public:
  using promise_type = Promise;
};

inline constexpr int getBarFromFoo(int foo) {
  return 0;
}

class MyClass {
  int myFoo;

  Task doSth();
};

Task MyClass::doSth() {
  co_await [&, this]() -> Task {
    co_await std::suspend_never();
    int bar = getBarFromFoo(myFoo);
  }();
}