The problem is, that having a local variable referring the same value
as the original expression 'foo' is not the same as referencing 'foo'
itself. After 'foo' is re-assigned, the local variable still refers
to the original value, not the new one.
It seems impossible to implement the reference using existing codegen
primitives, to imitate the true reference to 'foo', not to its value.
If we implement it by changing the runtime, the bytecode won't work
identically in older versions; if we introduce a new bytecode, that
would be an incompatible change.
As a workaround, only create the local With variable, when the block
variable is created using some function (as much as known by parser).
I think that there would be cases when this would still not work as
intended: an example is a property implemented using getter function;
the parser would likely treat the property as a variable, and avoid
creation of the local variable; and the getter would be called every
time a dot access will happen (which was the essence of tdf#132064).
However, this seems a better alternative to the bug fixed here.
Change-Id: I50bf679762fd2e73f215a000fa0ab60fd6ae7453
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/174564
Tested-by: Jenkins
Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>
Other "WITH" blocks create the symbol that can be found by pPool->Find,
but can be not accessible at the call site.
Change-Id: I85ecc763a1bb3fd692c2c98e674047fdbde3f8f5
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/173417
Tested-by: Jenkins
Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>
SbiRuntime::StepPUT, SbiRuntime::StepSET, SbiRuntime::StepVBASET call
checkUnoStructCopy eventually, which copies the UNO struct by value.
This is not what we need. On the other hand, SbiRuntime::StepPUTC only
makes the by-ref assignment, and makes the reference const; but Basic
code never assigns anything to the internal variable itself, only to
its members.
I hope that this time, I get it right.
Change-Id: I2b4a51a2dca9e7106e14e03360ef0d5a50b60079
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/173305
Tested-by: Jenkins
Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>
In commit f3f46b5fe7 (tdf#132064: make
With statement only evaluate its argument once, 2024-08-17), I made
a mistake, clearing the internal variable in the end of SbiParser::With
using an Erase call, which does not just clears the variable itself,
but destroys the underlying object, which is not what we need.
I don't know how to refer to a global Nothing object to assign to the
variable; so just create an own internal Nothing, and use it in the
assignment.
Change-Id: Ic8ce52e0402d8461a9b9e4ee07614c4f0a46a95e
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/172006
Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>
Tested-by: Jenkins
This is implemented by creating a unique variable at entry of the
block, using it as the "with parent", and clearing afterwards. It
uses an invalid name, so can't be used by a user. The generation
of the bytecode is done in compatible way; only existing opcodes
were used (which was the reason to choose the implementation with
a variable), so compiled binaries in password-protected libraries
are expected to work with older versions.
The functional changes are:
1. The argument of With statement is evaluated immediately at the
start of the block; previously, it evaluated first time, when the
leading dot operator was used, and could even be never evaluated,
if the operator wasn't used. This is consistent with VBA, and has
a benefit that the lifetime of the object is guaranteed to cover
the whole block (might be useful if other block statements depend
on the object, similar to Python's 'with' statement contexts).
2. The primary goal of the change: it is only ever evaluated once,
no matter how many times was the dot operator used in the block.
Change-Id: I4dbd520538a57e3668ab706e8f45740db5d33393
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/171980
Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>
Tested-by: Jenkins
Mike Kaganski