[PATCH] D123901: [LLVM][Casting.h] Update dyn_cast machinery to provide more control over how the casting is performed.

[Mikael Holmén via Phabricator via llvm-commits]

uabelho added a comment.

Did you notice this:

  FAILED: unittests/Support/CMakeFiles/SupportTests.dir/Casting.cpp.o 
  /home/buildbots/clang.11.0.0/bin/clang++ --gcc-toolchain=/opt/rh/devtoolset-7/root/usr  -DGTEST_HAS_RTTI=0 -D_DEBUG -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -Iunittests/Support -I/home/buildbots/docker-RHEL-buildbot/SetupBot/worker_env/ppc64le-clang-rhel-test/clang-ppc64le-rhel/llvm-project/llvm/unittests/Support -Iinclude -I/home/buildbots/docker-RHEL-buildbot/SetupBot/worker_env/ppc64le-clang-rhel-test/clang-ppc64le-rhel/llvm-project/llvm/include -I/home/buildbots/docker-RHEL-buildbot/SetupBot/worker_env/ppc64le-clang-rhel-test/clang-ppc64le-rhel/llvm-project/llvm/utils/unittest/googletest/include -I/home/buildbots/docker-RHEL-buildbot/SetupBot/worker_env/ppc64le-clang-rhel-test/clang-ppc64le-rhel/llvm-project/llvm/utils/unittest/googlemock/include -fPIC -fvisibility-inlines-hidden -Werror -Werror=date-time -Werror=unguarded-availability-new -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -pedantic -Wno-long-long -Wc++98-compat-extra-semi -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wsuggest-override -Wstring-conversion -Wmisleading-indentation -fdiagnostics-color -ffunction-sections -fdata-sections -O3 -DNDEBUG    -Wno-variadic-macros -Wno-gnu-zero-variadic-macro-arguments -fno-exceptions -fno-rtti -UNDEBUG -Wno-suggest-override -std=c++14 -MD -MT unittests/Support/CMakeFiles/SupportTests.dir/Casting.cpp.o -MF unittests/Support/CMakeFiles/SupportTests.dir/Casting.cpp.o.d -o unittests/Support/CMakeFiles/SupportTests.dir/Casting.cpp.o -c /home/buildbots/docker-RHEL-buildbot/SetupBot/worker_env/ppc64le-clang-rhel-test/clang-ppc64le-rhel/llvm-project/llvm/unittests/Support/Casting.cpp
  In file included from /home/buildbots/docker-RHEL-buildbot/SetupBot/worker_env/ppc64le-clang-rhel-test/clang-ppc64le-rhel/llvm-project/llvm/unittests/Support/Casting.cpp:9:
  /home/buildbots/docker-RHEL-buildbot/SetupBot/worker_env/ppc64le-clang-rhel-test/clang-ppc64le-rhel/llvm-project/llvm/include/llvm/Support/Casting.h:216:12: error: returning reference to local temporary object [-Werror,-Wreturn-stack-address]
      return Res2;
             ^~~~
  /home/buildbots/docker-RHEL-buildbot/SetupBot/worker_env/ppc64le-clang-rhel-test/clang-ppc64le-rhel/llvm-project/llvm/include/llvm/Support/Casting.h:453:72: note: in instantiation of member function 'llvm::cast_convert_val<llvm::foo, const llvm::bar, const llvm::bar>::doit' requested here
                              typename simplify_type<From>::SimpleType>::doit(f);
                                                                         ^
  /home/buildbots/docker-RHEL-buildbot/SetupBot/worker_env/ppc64le-clang-rhel-test/clang-ppc64le-rhel/llvm-project/llvm/include/llvm/Support/Casting.h:564:36: note: in instantiation of member function 'llvm::CastInfo<llvm::foo, const llvm::bar, void>::doCast' requested here
    return CastInfo<To, const From>::doCast(Val);
                                     ^
  /home/buildbots/docker-RHEL-buildbot/SetupBot/worker_env/ppc64le-clang-rhel-test/clang-ppc64le-rhel/llvm-project/llvm/include/llvm/Support/Casting.h:214:47: note: binding reference variable 'Res2' here
      typename cast_retty<To, FromTy>::ret_type Res2 =
                                                ^
  1 error generated.

from
 https://lab.llvm.org/buildbot/#/builders/57/builds/17829/steps/6/logs/stdio

I see the same thing compiling locally with clang 8.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D123901/new/

https://reviews.llvm.org/D123901