[Flang] Assertion `actual.isMutableBox() && "actual must be a mutable box"' failed.

[k-arrows]

Reproducer:

integer, allocatable :: a
call s((NULL(a)))
contains
    subroutine s(a)
        integer, allocatable :: a
        allocate(a)
        deallocate(a)
    end subroutine
end

With assertion-enabled flang, compiling the above reproducer results in the following assertion failure:

llvm-project/flang/lib/Lower/ConvertCall.cpp:1726: void prepareUserCallArguments(Fortran::lower::PreparedActualArguments &, Fortran::lower::CallerInterface &, mlir::FunctionType, (anonymous namespace)::CallContext &, llvm::SmallVector<CallCleanUp> &): Assertion `actual.isMutableBox() && "actual must be a mutable box"' failed.

Backtrace:

 #0 0x000075f1cc7b6717 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int)
 #1 0x000075f1cc7b3e15 llvm::sys::RunSignalHandlers()
 #2 0x000075f1cc7b74c5 SignalHandler(int, siginfo_t*, void*) Signals.cpp:0:0
 #3 0x000075f1cbe42520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
 #4 0x000075f1cbe969fc __pthread_kill_implementation ./nptl/pthread_kill.c:44:76
 #5 0x000075f1cbe969fc __pthread_kill_internal ./nptl/pthread_kill.c:78:10
 #6 0x000075f1cbe969fc pthread_kill ./nptl/pthread_kill.c:89:10
 #7 0x000075f1cbe42476 gsignal ./signal/../sysdeps/posix/raise.c:27:6
 #8 0x000075f1cbe287f3 abort ./stdlib/abort.c:81:7
 #9 0x000075f1cbe2871b _nl_load_domain ./intl/loadmsgcat.c:1177:9
#10 0x000075f1cbe39e96 (/lib/x86_64-linux-gnu/libc.so.6+0x39e96)
#11 0x000075f1cb1d8997 prepareUserCallArguments(llvm::SmallVector<std::optional<Fortran::lower::PreparedActualArgument>, 1u>&, Fortran::lower::CallerInterface&, mlir::FunctionType, (anonymous namespace)::CallContext&, llvm::SmallVector<(anonymous namespace)::CallCleanUp, 1u>&) ConvertCall.cpp:0:0
#12 0x000075f1cb1cf0f6 genUserCall(llvm::SmallVector<std::optional<Fortran::lower::PreparedActualArgument>, 1u>&, Fortran::lower::CallerInterface&, mlir::FunctionType, (anonymous namespace)::CallContext&) ConvertCall.cpp:0:0
#13 0x000075f1cb1cd6ab genProcedureRef((anonymous namespace)::CallContext&) ConvertCall.cpp:0:0
#14 0x000075f1cb1cbef7 Fortran::lower::convertCallToHLFIR(mlir::Location, Fortran::lower::AbstractConverter&, Fortran::evaluate::ProcedureRef const&, std::optional<mlir::Type>, Fortran::lower::SymMap&, Fortran::lower::StatementContext&) 

(trace continues...)

[llvmbot]

@llvm/issue-subscribers-flang-ir

Author: None (k-arrows)

Reproducer: ```f90 integer, allocatable :: a call s((NULL(a))) contains subroutine s(a) integer, allocatable :: a allocate(a) deallocate(a) end subroutine end ```

With assertion-enabled flang, compiling the above reproducer results in the following assertion failure:

llvm-project/flang/lib/Lower/ConvertCall.cpp:1726: void prepareUserCallArguments(Fortran::lower::PreparedActualArguments &, Fortran::lower::CallerInterface &, mlir::FunctionType, (anonymous namespace)::CallContext &, llvm::SmallVector<CallCleanUp> &): Assertion `actual.isMutableBox() && "actual must be a mutable box"' failed.

Backtrace:

 #<!-- -->0 0x000075f1cc7b6717 llvm::sys::PrintStackTrace(llvm::raw_ostream&amp;, int)
 #<!-- -->1 0x000075f1cc7b3e15 llvm::sys::RunSignalHandlers()
 #<!-- -->2 0x000075f1cc7b74c5 SignalHandler(int, siginfo_t*, void*) Signals.cpp:0:0
 #<!-- -->3 0x000075f1cbe42520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
 #<!-- -->4 0x000075f1cbe969fc __pthread_kill_implementation ./nptl/pthread_kill.c:44:76
 #<!-- -->5 0x000075f1cbe969fc __pthread_kill_internal ./nptl/pthread_kill.c:78:10
 #<!-- -->6 0x000075f1cbe969fc pthread_kill ./nptl/pthread_kill.c:89:10
 #<!-- -->7 0x000075f1cbe42476 gsignal ./signal/../sysdeps/posix/raise.c:27:6
 #<!-- -->8 0x000075f1cbe287f3 abort ./stdlib/abort.c:81:7
 #<!-- -->9 0x000075f1cbe2871b _nl_load_domain ./intl/loadmsgcat.c:1177:9
#<!-- -->10 0x000075f1cbe39e96 (/lib/x86_64-linux-gnu/libc.so.6+0x39e96)
#<!-- -->11 0x000075f1cb1d8997 prepareUserCallArguments(llvm::SmallVector&lt;std::optional&lt;Fortran::lower::PreparedActualArgument&gt;, 1u&gt;&amp;, Fortran::lower::CallerInterface&amp;, mlir::FunctionType, (anonymous namespace)::CallContext&amp;, llvm::SmallVector&lt;(anonymous namespace)::CallCleanUp, 1u&gt;&amp;) ConvertCall.cpp:0:0
#<!-- -->12 0x000075f1cb1cf0f6 genUserCall(llvm::SmallVector&lt;std::optional&lt;Fortran::lower::PreparedActualArgument&gt;, 1u&gt;&amp;, Fortran::lower::CallerInterface&amp;, mlir::FunctionType, (anonymous namespace)::CallContext&amp;) ConvertCall.cpp:0:0
#<!-- -->13 0x000075f1cb1cd6ab genProcedureRef((anonymous namespace)::CallContext&amp;) ConvertCall.cpp:0:0
#<!-- -->14 0x000075f1cb1cbef7 Fortran::lower::convertCallToHLFIR(mlir::Location, Fortran::lower::AbstractConverter&amp;, Fortran::evaluate::ProcedureRef const&amp;, std::optional&lt;mlir::Type&gt;, Fortran::lower::SymMap&amp;, Fortran::lower::StatementContext&amp;) 

(trace continues...)

[klausler]

If the actual argument had been declared INTENT(IN OUT), an error would have been produced by semantics because the actual argument is not definable. Without an INTENT, the actual argument is required to be definable at execution time.