[Scons-users] SCons.Node.Python.Value on target_factory

[Dirk Bächle]

Hi Philipp,

On 08.04.2013 12:00, Philipp Kraus wrote:

>

> Am 08.04.2013 um 07:33 schrieb Gary Oberbrunner:

>

>> [...]

>>

>>

>> I try to understand why primary file nodes used by scons, I think I 

>> see the build process more theoretically but Scons do it more 

>> practical, seems to be a mistake myself. Scons seems to work on 

>> physical existing file & dir nodes, so a creating of a pseudo node or 

>> URL node is very difficult, because the core for building must be 

>> changed.

>>


the SCons core works on Nodes (which can be anything, files, 
dirs,...)...but most of the wrapper functions that are aiming at being 
convenient for the standard user, assume that a file/dir node is what 
everybody wants. And they do this because it is, in fact, what the 
majority of our users want and need. Compiling and building things, 
based on files and directories.
Unfortunately, you don't seem to belong to this large group...and have 
to live with slight inconveniences here and there. One of them follows 
below...


>> For my example I expect, that a node, which is a Python.Value also 

>> build by default like a file node.


As Gary already pointed out, this expectation is wrong. If you want 
anything else but the '.' Dir node and its children to get built by 
default, you'll have to rearrange the dependency graph, such that your 
target is the child of another target (SCons will then update/build your 
target, because the other node depends on it). Another option is to use 
the Default() method, as described in the UserGuide (chap. 10.3.2 
"Controlling the Default Targets: The Default Function"). There is also 
an AlwaysBuild() method, for requested targets that should always be 
considered as out-of-date...

Best regards,

Dirk