tree 7a0e4604e7ff340509b67c262668e02c5aee934b
parent dccc08202910666b4f87cf0bf4df705b283ea571
author peter klausler <pklausler@nvidia.com> 1611956062 -0800
committer Copybara-Service <copybara-worker@google.com> 1612516945 -0800

[flang] Support disabled alternative PARAMETER statement

Legacy Fortran implementations support an alternative form of the
PARAMETER statement; it differs syntactically from the standard's
PARAMETER statement by lacking parentheses, and semantically by
using the type and shape of the initialization expression to define
the attributes of the named constant.  (GNU Fortran gets that part
wrong; Intel Fortran and nvfortran have full support.)

This patch disables the old style PARAMETER statement by default, as
it is syntactically ambiguous with conforming assignment statements;
adds a new "-falternative-parameter-statement" option to enable it;
and implements it correctly when enabled.

Fixes https://bugs.llvm.org/show_bug.cgi?id=48774, in which a user
tripped over the syntactic ambiguity.

Differential Revision: https://reviews.llvm.org/D95697

GitOrigin-RevId: ebe74d9592d097501f376c2086e58d35aa318896