Question about injectContext

[David Nolden]

2011/3/22 Sven Brauch <svenbrauch at googlemail.com>:
> I'd like to create a member variable declaration for a class if an
> attribute is written at any instance of that class, for example (A is
> a class): "instance = A(); instance->x = 3" -- then I'd like to create
> a class member declaration for x, if none exists yet.
> Isn't this the use case injectContext is meant for? I would like to

No, at least in C++, injectContext is mainly just used for to
temporarily change the visibility to have the same visibility as from
within the given context (at least from what I remember).

The deletion of the declarations most probably happens because the
declaration cannot be matched properly during updating. Whenever the
context is re-parsed, the declaration-builder notices that the
declaration was not matched, and deletes it again. This happens
because you don't create the declaration while the context is _really_
built. The issue regarding the navigation-widget happens because the
duchain does the sane assumption that each declaration happens within
the range of the enclosing context.

I have already thought about these issues for languages like python,
and I think the solution would be:
1) Add a "isAutoDeclaration" 1-bit bool flag to Declaration, which
says whether the declaration was created "automatically" through a use
of it, and always declare this for python variables.
2) In the context-builder while closing a context: Instead of deleting
all non-encountered declarations, leave alive non-encountered
declarations with the "isAutoDeclaration" flag _only if_ it has uses.
3) When the declaration is used:
4.1) If the declaration does not exist yet, create it the way you're
doing now, but with an empty range that is contained by the correct
class-context, and with the isAutoDeclaration set.
4.2) Create a use of the declaration, with the correct range. This
will make the navigation-widget work.

I think this would be the most clean way to do it. Maybe the php
developers also have something to add, as they might be dealing with
similar issues.

Greetings, David