[all-commits] [llvm/llvm-project] 1a65d0: [flang][runtime] Keep frame buffer in sync with fi...

[Peter Klausler via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 1a65d09dcf9b9bed89f8c4fd848a056ebb507597
      https://github.com/llvm/llvm-project/commit/1a65d09dcf9b9bed89f8c4fd848a056ebb507597
  Author: Peter Klausler <pklausler at nvidia.com>
  Date:   2022-07-13 (Wed, 13 Jul 2022)

  Changed paths:
    M flang/runtime/buffer.h
    M flang/runtime/unit.cpp

  Log Message:
  -----------
  [flang][runtime] Keep frame buffer in sync with file when truncating

When the I/O runtime is truncating an external file due to an
implied ENDFILE or explicit ENDFILE, ensure that the unit's frame
buffer for the file discards any data that have become obsolete.

This bug caused trouble with ACCESS='STREAM' I/O using POS= on
a WRITE, but it may have not been limited to that scenario.

Differential Revision: https://reviews.llvm.org/D129673