[Cling] Typing an error in a formula may be followed by an unresolved while linking error

[guitargeek]

Moved from the following JIRA issue:

• https://its.cern.ch/jira/browse/ROOT-9656

The reason I moved this issue to our GitHub was that like this I can also cross-link it from the corresponding clang-repl issue:

• clang-repl: Typing an error in a formula may be followed by an unresolved while linking error llvm/llvm-project#146770

In some cases, the interpreter doesn't recover correctly from input errors, resulting in a state where unexpected linker errors can happen in correct statements given afterwards.

It seems that this kind of error occurs only with "pow".

Reproducer with ROOT master:

   ------------------------------------------------------------------
  | Welcome to ROOT 6.37.01                        https://root.cern |
  | (c) 1995-2025, The ROOT Team; conception: R. Brun, F. Rademakers |
  | Built for linuxx8664gcc on Jan 01 1980, 00:00:00                 |
  | From heads/master@v6-37-01-7256-geaa43c05ef9                     |
  | With g++ (GCC) 14.3.0                                            |
  | Try '.help'/'.?', '.demo', '.license', '.credits', '.quit'/'.q'  |
   ------------------------------------------------------------------

root [0] (10-)*std::pow(2,2)
ROOT_prompt_0:1:5: error: expected expression
(10-)*std::pow(2,2)
    ^
root [1] (10-1)*std::pow(2,2)
IncrementalExecutor::executeFunction: symbol '_ZSt3powIiiEN9__gnu_cxx9__promoteIDTplcvNS1_IT_Xsr3std12__is_integerIS2_EE7__valueEE6__typeELi0EcvNS1_IT0_Xsr3std12__is_integerIS5_EE7__valueEE6__typeELi0EEXsr3std12__is_integerIS8_EE7__valueEE6__typeES2_S5_' unresolved while linking [cling interface function]!
You are probably missing the definition of __gnu_cxx::__promote<decltype (((__gnu_cxx::__promote<int, std::__is_integer<int>::__value>::__type)(0))+((__gnu_cxx::__promote<int, std::__is_integer<int>::__value>::__type)(0))), std::__is_integer<decltype (((__gnu_cxx::__promote<int, std::__is_integer<int>::__value>::__type)(0))+((__gnu_cxx::__promote<int, std::__is_integer<int>::__value>::__type)(0)))>::__value>::__type std::pow<int, int>(int, int)
Maybe you need to load the corresponding shared library?
root [2]

[dpiparo]

@devajithvs do you think the cause of this problem is the same of the one behind what's reported here #6439 ? If yes, we can mark that one as duplicate (or fix both with one PR)

[devajithvs]

@devajithvs do you think the cause of this problem is the same of the one behind what's reported here #6439 ? If yes, we can mark that one as duplicate (or fix both with one PR)

Upon initial debugging, this seems to be very specific to certain math funtions: fmax, fmin, atan2, fmod, pow (and a few more) when they are called with int arguments and seems to be separate from the linked issue.

The problem disappears with std::pow(2.0, 2.0)) for instance. I'm looking into this further.