[PATCH, Fortran] DEC Compatibility: New I/O Specifiers CARRIAGECONTROL, READONLY, SHARE with -fdec

[Fritz Reese <fritzoreese at gmail dot com>]

All,

Here's the big one. This patch proposes an extension to both the GNU
Fortran front-end and runtime library (libgfortran) to support three
additional I/O specifiers: CARRIAGECONTROL, READONLY, and SHARE for
compatibility with legacy compilers/code.

Here's a summary of what the specifiers actually do:
CARRIAGECONTROL is to control line termination settings between output records.
READONLY implies ACTION='READ' and additionally prevents
STATUS='DELETE' from deleting a file on CLOSE.
SHARE provides OS-level locks.

These specifiers are designed to match the syntax and behavior of
legacy compilers. For more info see the attached test cases, source
code, and documentation.

Each comes with an IOPARM_OPEN_ bit, and CC+SHARE have IOPARM_INQUIRE_
bits. The st_parameter_dt structure needs an additional two bytes to
propagate information with CARRIAGECONTROL='FORTRAN'. These two bytes
still leave plenty of trailing 'pad' for future expansion.

Bootstraps and regtests on x86_64-redhat-linux. There's a fair bit to
sift through, so feel free to ask for clarification or provide
comments/constructive criticism.

OK for trunk?

---
Fritz Reese

From: Fritz Reese <fritzoreese@gmail.com>
Date: Wed, 5 Oct 2016 20:18:16 -0400
Subject: [PATCH] New I/O specifiers CARRIAGECONTROL, READONLY, SHARE with -fdec

        gcc/fortran/
        * gfortran.texi: Document.
        * frontend-passes.c (gfc_code_walker): Add SHARE and CARRIAGECONTROL.
        * io.c (gfc_free_open, gfc_resolve_open, gfc_match_open): Ditto.
        * gfortran.h (gfc_open): Add SHARE, CARRIAGECONTROL, and READONLY.
        * io.c (io_tag, match_open_element): Ditto.
        * ioparm.def: Ditto.
        * trans-io.c (gfc_trans_open): Ditto.
        * io.c (match_dec_etag, match_dec_ftag): New functions.

        libgfortran/io/
        * libgfortran.h (IOPARM_OPEN_HAS_READONLY, IOPARM_OPEN_HAS_SHARE,
        IOPARM_OPEN_HAS_CC): New for READONLY, SHARE, and CARRIAGECONTROL.
        * close.c (st_close): Support READONLY.
        * io.h (st_parameter_open, unit_flags): Support SHARE, CARRIAGECONTROL,
        and READONLY.
        * open.c (st_open): Ditto.
        * transfer.c (data_transfer_init): Ditto.
        * io.h (st_parameter_dt): New member 'cc' for CARRIAGECONTROL.
        * write.c (write_check_cc, write_cc): New functions for CARRIAGECONTROL.
        * transfer.c (next_record_cc): Ditto.
        * file_pos.c (st_endfile): Support SHARE and CARRIAGECONTROL.
        * io.h (st_parameter_inquire): Ditto.
        * open.c (edit_modes, new_unit): Ditto.
        * inquire.c (inquire_via_unit, inquire_via_filename): Ditto.
        * io.h (unit_share, unit_cc, cc_fortran, IOPARM_INQUIRE_HAS_SHARE,
        IOPARM_INQUIRE_HAS_CC): New for SHARE and CARRIAGECONTROL.
        * open.c (share_opt, cc_opt): Ditto.
        * read.c (read_x): Support CARRIAGECONTROL.
        * transfer.c (read_sf, next_record_r, next_record_w): Ditto.
        * write.c (list_formatted_write_scalar, write_a): Ditto.
        * unix.h (close_share): New prototype.
        * unix.c (open_share, close_share): New functions to handle SHARE.
        * unix.c (open_external): Handle READONLY. Call open_share.
        * close.c (st_close): Call close_share.

        gcc/testsuite/
        * dec_io_1.f90: New test.
        * dec_io_2.f90: New test.
        * dec_io_3.f90: New test.
        * dec_io_4.f90: New test.
        * dec_io_5.f90: New test.
        * dec_io_6.f90: New test.
---
 gcc/fortran/frontend-passes.c          |    2 +
 gcc/fortran/gfortran.h                 |    6 +-
 gcc/fortran/gfortran.texi              |   92 ++++++++++++++++-
 gcc/fortran/io.c                       |  177 +++++++++++++++++++++++++++++++-
 gcc/fortran/ioparm.def                 |    6 +
 gcc/fortran/trans-io.c                 |   15 +++
 gcc/testsuite/gfortran.dg/dec_io_1.f90 |  101 ++++++++++++++++++
 gcc/testsuite/gfortran.dg/dec_io_2.f90 |  104 +++++++++++++++++++
 gcc/testsuite/gfortran.dg/dec_io_3.f90 |   15 +++
 gcc/testsuite/gfortran.dg/dec_io_4.f90 |   17 +++
 gcc/testsuite/gfortran.dg/dec_io_5.f90 |   17 +++
 gcc/testsuite/gfortran.dg/dec_io_6.f90 |   15 +++
 libgfortran/io/close.c                 |   16 ++-
 libgfortran/io/file_pos.c              |    2 +
 libgfortran/io/inquire.c               |   58 +++++++++++
 libgfortran/io/io.h                    |   51 +++++++++
 libgfortran/io/open.c                  |   47 +++++++++
 libgfortran/io/read.c                  |    3 +-
 libgfortran/io/transfer.c              |   59 +++++++++--
 libgfortran/io/unit.c                  |    6 +
 libgfortran/io/unix.c                  |   89 ++++++++++++++++-
 libgfortran/io/unix.h                  |    3 +
 libgfortran/io/write.c                 |  141 +++++++++++++++++++++++++-
 libgfortran/libgfortran.h              |    4 +
 24 files changed, 1024 insertions(+), 22 deletions(-)
 create mode 100644 gcc/testsuite/gfortran.dg/dec_io_1.f90
 create mode 100644 gcc/testsuite/gfortran.dg/dec_io_2.f90
 create mode 100644 gcc/testsuite/gfortran.dg/dec_io_3.f90
 create mode 100644 gcc/testsuite/gfortran.dg/dec_io_4.f90
 create mode 100644 gcc/testsuite/gfortran.dg/dec_io_5.f90
 create mode 100644 gcc/testsuite/gfortran.dg/dec_io_6.f90

Attachment: dec_io.diff
Description: Text document