[Scons-users] Environment clones linked?

So you're reaching into an Action defined in a builder.
That's pretty far inside the Environment to a level that there's not a deep
copy of it.

This when using mslink right?

shlibLinkAction = SCons.Action.Action('${TEMPFILE("$SHLINK
$SHLINKFLAGS $_SHLINK_TARGETS $_LIBDIRFLAGS $_LIBFLAGS $_PDB
$_SHLINK_SOURCES", "$SHLINKCOMSTR")}', '$SHLINKCOMSTR')

regServerAction = SCons.Action.Action("$REGSVRCOM", "$REGSVRCOMSTR")

embedManifestDllCheckAction = SCons.Action.Action(embedManifestDllCheck, None)

compositeShLinkAction = shlibLinkAction + regServerCheck +
embedManifestDllCheckAction

env['SHLINKCOM'] = compositeShLinkAction

In this case I'd expect the Clone copy/deep copying logic would yield what
you are seeing.
If you did this:

env2['SHLINKCOM'] = SCons.Action.Action("echo link command env2",None) +
env2['SHLINKCOM'].list[1] + env2['SHLINKCOM'].list[2]

Then it shouldn't modify env1..
-Bill

Post by Daniel Moody
I am trying to clone an environment and then make changes to the clone so
that it is different than the original.
But somehow changing the clone also changes my original env? Is that
expected behavior?
Below is an example SConstruct which reproduces the issue (SCons 3.01
env1 = Environment()
env2 = env1.Clone()
print("env2 before = " + env1['SHLINKCOM'].list[0].cmd_list)
env2['SHLINKCOM'].list[0].cmd_list = "echo link command env2"
print("env2 after = " + env1['SHLINKCOM'].list[0].cmd_list)
print("env1 = " + env2['SHLINKCOM'].list[0].cmd_list)
C:\Users\Daniel\workspace>scons -f SConstruct.py
scons: Reading SConscript files ...
env2 before = ${TEMPFILE("$SHLINK $SHLINKFLAGS $_SHLINK_TARGETS
$_LIBDIRFLAGS $_LIBFLAGS $_PDB $_SHLINK_SOURCES", "$SHLINKCOMSTR")}
env2 after = echo link command env2
env1 = echo link command env2
scons: done reading SConscript files.
scons: Building targets ...
scons: `.' is up to date.
scons: done building targets.
Can someone shed some light on if this is a bug or how do I uniquely
modify the SHLINKCOM?
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Daniel Moody

2018-05-25 04:23:03 UTC

Thanks that worked!

I didn't understand how deep Clone went. Originally I tried to modify the
Action command directly because I didn't want to mess with the other
actions for the SHLINKCOM.

Post by Bill Deegan
So you're reaching into an Action defined in a builder.
That's pretty far inside the Environment to a level that there's not a
deep copy of it.
This when using mslink right?
shlibLinkAction = SCons.Action.Action('${TEMPFILE("$SHLINK $SHLINKFLAGS $_SHLINK_TARGETS $_LIBDIRFLAGS $_LIBFLAGS $_PDB $_SHLINK_SOURCES", "$SHLINKCOMSTR")}', '$SHLINKCOMSTR')
regServerAction = SCons.Action.Action("$REGSVRCOM", "$REGSVRCOMSTR")
embedManifestDllCheckAction = SCons.Action.Action(embedManifestDllCheck, None)
compositeShLinkAction = shlibLinkAction + regServerCheck + embedManifestDllCheckAction
env['SHLINKCOM'] = compositeShLinkAction
In this case I'd expect the Clone copy/deep copying logic would yield what
you are seeing.
env2['SHLINKCOM'] = SCons.Action.Action("echo link command env2",None) +
env2['SHLINKCOM'].list[1] + env2['SHLINKCOM'].list[2]
Then it shouldn't modify env1..
-Bill

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https://pairlist4.pair.net/mailman/listinfo/scons-users

Jonathon Reinhart

2018-05-25 14:25:41 UTC

We've fought this exact issue before as well: Modifications to Actions
or ActionLists affect all environments.

The key, as Bill explained, is to leverage the indirection that the
environments provide via the *COM variables. In our case, we actually
append to the action lists in the environments.

Jonathon

Post by Daniel Moody
Thanks that worked!
I didn't understand how deep Clone went. Originally I tried to modify the
Action command directly because I didn't want to mess with the other actions
for the SHLINKCOM.

Post by Bill Deegan
So you're reaching into an Action defined in a builder.
That's pretty far inside the Environment to a level that there's not a
deep copy of it.
This when using mslink right?
shlibLinkAction = SCons.Action.Action('${TEMPFILE("$SHLINK $SHLINKFLAGS
$_SHLINK_TARGETS $_LIBDIRFLAGS $_LIBFLAGS $_PDB $_SHLINK_SOURCES",
"$SHLINKCOMSTR")}', '$SHLINKCOMSTR')
regServerAction = SCons.Action.Action("$REGSVRCOM", "$REGSVRCOMSTR")
embedManifestDllCheckAction = SCons.Action.Action(embedManifestDllCheck, None)
compositeShLinkAction = shlibLinkAction + regServerCheck +
embedManifestDllCheckAction
env['SHLINKCOM'] = compositeShLinkAction
In this case I'd expect the Clone copy/deep copying logic would yield what
you are seeing.
env2['SHLINKCOM'] = SCons.Action.Action("echo link command env2",None) +
env2['SHLINKCOM'].list[1] + env2['SHLINKCOM'].list[2]
Then it shouldn't modify env1..
-Bill

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Scons-users mailing list
https://pairlist4.pair.net/mailman/listinfo/scons-users

Bill Deegan

2018-05-25 15:01:26 UTC

Any thoughts on how better to document this?
More verbiage under Clone()

You're already in the deep end of the pool when you're doing this kind of
SCons code though..

On Fri, May 25, 2018 at 9:25 AM, Jonathon Reinhart <

Post by Jonathon Reinhart
We've fought this exact issue before as well: Modifications to Actions
or ActionLists affect all environments.
The key, as Bill explained, is to leverage the indirection that the
environments provide via the *COM variables. In our case, we actually
append to the action lists in the environments.
Jonathon

Post by Daniel Moody
Thanks that worked!
I didn't understand how deep Clone went. Originally I tried to modify the
Action command directly because I didn't want to mess with the other

actions

Post by Daniel Moody
for the SHLINKCOM.

embedManifestDllCheck,

Post by Bill Deegan
None)
compositeShLinkAction = shlibLinkAction + regServerCheck +
embedManifestDllCheckAction
env['SHLINKCOM'] = compositeShLinkAction
In this case I'd expect the Clone copy/deep copying logic would yield

what

Post by Bill Deegan
you are seeing.
env2['SHLINKCOM'] = SCons.Action.Action("echo link command env2",None) +
env2['SHLINKCOM'].list[1] + env2['SHLINKCOM'].list[2]
Then it shouldn't modify env1..
-Bill

Post by Daniel Moody
I am trying to clone an environment and then make changes to the clone

Post by Daniel Moody
that it is different than the original.
But somehow changing the clone also changes my original env? Is that
expected behavior?
Below is an example SConstruct which reproduces the issue (SCons 3.01
env1 = Environment()
env2 = env1.Clone()
print("env2 before = " + env1['SHLINKCOM'].list[0].cmd_list)
env2['SHLINKCOM'].list[0].cmd_list = "echo link command env2"
print("env2 after = " + env1['SHLINKCOM'].list[0].cmd_list)
print("env1 = " + env2['SHLINKCOM'].list[0].cmd_list)
C:\Users\Daniel\workspace>scons -f SConstruct.py
scons: Reading SConscript files ...
env2 before = ${TEMPFILE("$SHLINK $SHLINKFLAGS $_SHLINK_TARGETS
$_LIBDIRFLAGS $_LIBFLAGS $_PDB $_SHLINK_SOURCES", "$SHLINKCOMSTR")}
env2 after = echo link command env2
env1 = echo link command env2
scons: done reading SConscript files.
scons: Building targets ...
scons: `.' is up to date.
scons: done building targets.
Can someone shed some light on if this is a bug or how do I uniquely
modify the SHLINKCOM?
_______________________________________________
Scons-users mailing list
https://pairlist4.pair.net/mailman/listinfo/scons-users

_______________________________________________
Scons-users mailing list
https://pairlist4.pair.net/mailman/listinfo/scons-users

Jonathon Reinhart

2018-05-25 18:28:25 UTC

Yes a friendly warning might be helpful, pointing out that Clone() is
not a totally deep-clone, and that specifically Action objects remain
linked.

You might also consider going on to say that the correct way to
manipulate the way Actions work on a per-environment basis is to
manipulate the *COM variables which the Actions reference.

Post by Bill Deegan
Any thoughts on how better to document this?
More verbiage under Clone()
You're already in the deep end of the pool when you're doing this kind of
SCons code though..
On Fri, May 25, 2018 at 9:25 AM, Jonathon Reinhart

Post by Bill Deegan
So you're reaching into an Action defined in a builder.
That's pretty far inside the Environment to a level that there's not a
deep copy of it.
This when using mslink right?
shlibLinkAction = SCons.Action.Action('${TEMPFILE("$SHLINK $SHLINKFLAGS
$_SHLINK_TARGETS $_LIBDIRFLAGS $_LIBFLAGS $_PDB $_SHLINK_SOURCES",
"$SHLINKCOMSTR")}', '$SHLINKCOMSTR')
regServerAction = SCons.Action.Action("$REGSVRCOM", "$REGSVRCOMSTR")
embedManifestDllCheckAction =
SCons.Action.Action(embedManifestDllCheck,
None)
compositeShLinkAction = shlibLinkAction + regServerCheck +
embedManifestDllCheckAction
env['SHLINKCOM'] = compositeShLinkAction
In this case I'd expect the Clone copy/deep copying logic would yield what
you are seeing.
env2['SHLINKCOM'] = SCons.Action.Action("echo link command env2",None) +
env2['SHLINKCOM'].list[1] + env2['SHLINKCOM'].list[2]
Then it shouldn't modify env1..
-Bill

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Scons-users mailing list
https://pairlist4.pair.net/mailman/listinfo/scons-users

Bill Deegan

2018-05-25 18:35:33 UTC

Pull request? ;)

On Fri, May 25, 2018 at 1:28 PM, Jonathon Reinhart <

Post by Jonathon Reinhart
Yes a friendly warning might be helpful, pointing out that Clone() is
not a totally deep-clone, and that specifically Action objects remain
linked.
You might also consider going on to say that the correct way to
manipulate the way Actions work on a per-environment basis is to
manipulate the *COM variables which the Actions reference.

Post by Bill Deegan
So you're reaching into an Action defined in a builder.
That's pretty far inside the Environment to a level that there's not

Post by Bill Deegan
deep copy of it.
This when using mslink right?
shlibLinkAction = SCons.Action.Action('${TEMPFILE("$SHLINK

$SHLINKFLAGS

Post by Bill Deegan
$_SHLINK_TARGETS $_LIBDIRFLAGS $_LIBFLAGS $_PDB $_SHLINK_SOURCES",
"$SHLINKCOMSTR")}', '$SHLINKCOMSTR')
regServerAction = SCons.Action.Action("$REGSVRCOM", "$REGSVRCOMSTR")
embedManifestDllCheckAction =
SCons.Action.Action(embedManifestDllCheck,
None)
compositeShLinkAction = shlibLinkAction + regServerCheck +
embedManifestDllCheckAction
env['SHLINKCOM'] = compositeShLinkAction
In this case I'd expect the Clone copy/deep copying logic would yield what
you are seeing.
env2['SHLINKCOM'] = SCons.Action.Action("echo link command

env2",None)

Post by Bill Deegan
+
env2['SHLINKCOM'].list[1] + env2['SHLINKCOM'].list[2]
Then it shouldn't modify env1..
-Bill

Post by Daniel Moody
I am trying to clone an environment and then make changes to the

clone

Post by Daniel Moody
so
that it is different than the original.
But somehow changing the clone also changes my original env? Is that
expected behavior?
Below is an example SConstruct which reproduces the issue (SCons

3.01