[all-commits] [llvm/llvm-project] 0478ea: [lldb/DataFormatters] Fix the `$$deference$$` synt...

[fredriss via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 0478eadf73c191199cba12c85785cfafb8bfa174
      https://github.com/llvm/llvm-project/commit/0478eadf73c191199cba12c85785cfafb8bfa174
  Author: Fred Riss <friss at apple.com>
  Date:   2020-01-21 (Tue, 21 Jan 2020)

  Changed paths:
    M lldb/docs/use/variable.rst
    M lldb/packages/Python/lldbsuite/test/functionalities/data-formatter/data-formatter-python-synth/TestDataFormatterPythonSynth.py
    M lldb/packages/Python/lldbsuite/test/functionalities/data-formatter/data-formatter-python-synth/fooSynthProvider.py
    M lldb/packages/Python/lldbsuite/test/functionalities/data-formatter/data-formatter-python-synth/main.cpp
    M lldb/source/Core/ValueObject.cpp

  Log Message:
  -----------
  [lldb/DataFormatters] Fix the `$$deference$$` synthetic child

Summary:
The ValueObject code checks for a special `$$dereference$$` synthetic
child to allow formatter providers to implement a natural
dereferencing behavior in `frame variable` for objects like smart
pointers.

This support was broken when used directly throught the Python API and
not trhough `frame variable`. The reason is that
SBFrame.FindVariable() will return by default the synthetic variable
if it exists, while `frame variable` will not do this eagerly. The
code in `ValueObject::Dereference()` accounted for the latter but not
for the former. The fix is trivial. The test change includes
additional covergage for the already-working bahevior as it wasn't
covered by the testsuite before.

This commit also adds a short piece of documentatione explaining that
it is possible (even advisable) to provide this synthetic child
outstide of the range of the normal children.

Reviewers: jingham

Subscribers: lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D73053