llvm-project

43e4757d - [flang][semantic] update semantic checks for ansychronous and volatility attributes to use MayNeedCopy (#159477)

[flang][semantic] update semantic checks for ansychronous and volatility attributes to use MayNeedCopy (#159477) Ties the semantic checks for overwriting a asynchronous or volatile value with a copy-out operation to the function `evaluate::MayNeedCopy(..., /*forCopyOut=*/false)`. This should make the checks more accurate and consistent with the lowering. The PR also adds a default check that looks for the undesired behavior directly, in case extension later modify what is possible. A couple portability warnings are added where other compilers are over restrictive. Closes https://github.com/llvm/llvm-project/issues/137369 ``` $ build/bin/flang -c ~/work/llvm-test-suite/Fortran/gfortran/regression/volatile8.f90 -pedantic /home/akuhlenschmi/work/llvm-test-suite/Fortran/gfortran/regression/volatile8.f90:21:16: warning: The array section 'a(1_8:5_8:2_8)' should not be associated with dummy argument 'dummy8=' with VOLATILE attribute, unless the dummy is assumed-shape or assumed-rank [-Wvolatile-or-asynchronous-temporary] call sub8 (a(1:5:2)) ! { dg-error "Array-section actual argument" } ^^^^^^^^ /home/akuhlenschmi/work/llvm-test-suite/Fortran/gfortran/regression/volatile8.f90:37:16: portability: The actual argument 's9dummy' should not be associated with dummy argument 'dummy9=' with VOLATILE attribute, because a temporary copy is required during the call [-Wportability] call sub9 (s9dummy) ! { dg-error "Assumed-shape actual argument" } ^^^^^^^ /home/akuhlenschmi/work/llvm-test-suite/Fortran/gfortran/regression/volatile8.f90:55:17: portability: The actual argument 'a' should not be associated with dummy argument 'dummy10=' with VOLATILE attribute, because a temporary copy is required during the call [-Wportability] call sub10 (a) ! { dg-error "Pointer-array actual argument" } ^ ```