[PATCH] D154869: [Flang] [FlangRT] Introduce FlangRT project as solution to Flang's runtime LLVM integration

Sun Oct 1 10:00:01 PDT 2023

pscoro added a comment.

In D154869#4652224 <https://reviews.llvm.org/D154869#4652224>, @sylvestre.ledru wrote:

> With this patch, it started to fail with:
> It would be nice to have a better error message suggesting what to do
>
>   -- Performing Test HAVE_DECL_STRERROR_S
>   -- Performing Test HAVE_DECL_STRERROR_S - Failed
>   CMake Error at /build/source/flang-rt/unittests/CMakeLists.txt:37 (message):
>     Target llvm_gtest not found.
>   
>   
>   -- Configuring incomplete, errors occurred!

Hi, I originally authored this patch but **I am no longer actively involved in Flang's development at the moment**, however, I've been getting notifications that this patch has been landed yesterday and subsequently, the failing buildbots.
I believe all the gtest not found errors originate from a missing build flag, as per the documentation page for flang-rt in `flang-rt/docs/GettingStarted.md`:

  # We need to enable GTest if we want to run Flang-rt's testsuites
  -DLLVM_INSTALL_GTEST=On \

I believe I saw that clang buildbots also got inadvertently by this cmake change as well.
Wish I had time to investigate this further myself, hopefully @madanial can take a closer look. I believe what needs to be done is:

- flang buildbots need their build flags updated to include `-DLLVM_INSTALL_GTEST=On`
- The `Target llvm_gtest not found.` should be improved to offer better guidance
- The clang failures should be looked at closer; see if its possible to make a change to the cmake to limit the scope of builds needing the `-DLLVM_INSTALL_GTEST=On` flag update to just be flang builds. If there is no simple way to limit the scope, then updating the build flags for the clang builders is another solution
- I noticed at least one flang builder (https://lab.llvm.org/buildbot/#/builders/191/builds/24124) is failing build with:

  FAILED: bin/external-hello-world 
  : && /usr/local/bin/c++ -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -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 -Wctad-maybe-unsupported -fdiagnostics-color -ffunction-sections -fdata-sections -Wno-deprecated-copy -Wno-string-conversion -Wno-ctad-maybe-unsupported -Wno-unused-command-line-argument -Wstring-conversion           -Wcovered-switch-default -Wno-nested-anon-types -O3 -DNDEBUG -Wl,-rpath-link,/home/tcwg-buildbot/worker/flang-aarch64-rel-assert/build/./lib  -Wl,--gc-sections tools/flang/examples/ExternalHelloWorld/CMakeFiles/external-hello-world.dir/external-hello.cpp.o -o bin/external-hello-world  -Wl,-rpath,"\$ORIGIN/../lib:"  -lpthread  -lFortranRuntime && :
  /usr/bin/ld: cannot find -lFortranRuntime

This looks to be a usage of the old FortranRuntime configuration that I overlooked and so it wasnt updated. This should be linking flang-rt instead of FortranRuntime

Hopefully addressing these small issues will get the buildbots green again, sorry for the disruptions.

Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D154869/new/

https://reviews.llvm.org/D154869