Summary:
The interactions between the environment settings (`target.env-vars`,
`target.inherit-env`) and the inferior life-cycle are non-obvious
today. For example, if `target.inherit-env` is set, the `target.env-vars`
setting will be augmented with the contents of the host environment
the first time the launch environment is queried (usually at
launch). After that point, toggling `target.inherit-env` will have no
effect as there's no tracking of what comes from the host and what is
a user setting.
This patch computes the environment every time it is queried rather
than updating the contents of the `target.env-vars` property. This
means that toggling the `target.inherit-env` property later will now
have the intended effect.
This patch also adds a `target.unset-env-vars` settings that one can
use to remove variables from the launch environment. Using this, you
can inherit all but a few of the host environment.
The way the launch environment is constructed is:
1/ if `target.inherit-env` is set, then read the host environment
into the launch environment.
2/ Remove for the environment the variables listed in
`target.unset-env`.
3/ Augment the launch environment with the contents of
`target.env-vars`. This overrides any common values with the host
environment.
The one functional difference here that could be seen as a regression
is that `target.env-vars` will not contain the inferior environment
after launch. The patch implements a better alternative in the
`target show-launch-environment` command which will return the
environment computed through the above rules.
Reviewers: labath, jingham
Subscribers: lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D76470