Scons. Go recursive with Glob - scons

Question

I using scons for a few days and confused a bit. Why there is no built-in tools for building sources recursively starting from given root? Let me explain:
I have such source disposition:
src
Core
folder1
folder2
subfolder2_1
Std
folder1
..and so on. This tree could be rather deeper.
Now I build this with such construction:
sources = Glob('./builds/Std/*/*.cpp')
sources = sources + Glob('./builds/Std/*.cpp')
sources = sources + Glob('./builds/Std/*/*/*.cpp')
sources = sources + Glob('./builds/Std/*/*/*/*.cpp')
and this looks not so perfect as at can be. Of cause, I can write some python code, but
is there more suitable ways of doing this?

Answer 1

As Torsten already said, there is no "internal" recursive Glob() in SCons. You need to write something yourself. My solution is:
import fnmatch
import os
matches = []
for root, dirnames, filenames in os.walk('src'):
for filename in fnmatch.filter(filenames, '*.c'):
matches.append(Glob(os.path.join(root, filename)[len(root)+1:]))
I want to stress that you need Glob() here (not glob.glob() from python) especially when you use VariantDir(). Also when you use VariantDir() don't forget to convert absolute paths to relative (in the example I achieve this using [len(root)+1:]).

Answer 2

Sure.
You need to write python wrappers to walking through dirs. You can find many recipes on stackoverflow.
Here is my simple function which returns list of subdirs in present dir (and ignore hide dirs starting with '.' - dot)
def getSubdirs(abs_path_dir) :
lst = [ name for name in os.listdir(abs_path_dir) if os.path.isdir(os.path.join(abs_path_dir, name)) and name[0] != '.' ]
lst.sort()
return lst
For example, i've dir modules what containts foo, bar, ice.
corePath = 'abs/path/to/modules'
modules = getSubdirs(corePath)
# modules = [bar, foo, ice]
for module in modules :
sources += Glob(os.path.join(corePath, module, '*.cpp'))
You can improve getSubdirs function adding recurse and walking deeper to subdirs.

Answer 3

The Glob() SCons function doesnt have the ability to go recursive.
It would be much more efficient if you change your Python code to use the list.extend() function, like this:
sources = Glob('./builds/Std/*/*.cpp')
sources.extend(Glob('./builds/Std/*.cpp'))
sources.extend(Glob('./builds/Std/*/*/*.cpp'))
sources.extend(Glob('./builds/Std/*/*/*/*.cpp'))
Instead of trying to go recursive like you are, its quite common to have a SConscript script in each subdirectory and in the root SConstruct call each of them with the SConscript() function. This is called a SCons hierarchical build.

Answer 4

Here is my version of recursive Glob:
from SCons.Environment import Base as BaseEnvironment
def __RGlob(self, root_path, pattern, ondisk=True, source=False, strings=False, exclude=None):
result_nodes = []
paths = [root_path]
while paths:
path = paths.pop()
all_nodes = self.Glob(f'{path}/*', ondisk=ondisk, source=source, exclude=exclude)
paths.extend(entry for entry in all_nodes if entry.isdir() or (entry.srcnode() and entry.srcnode().isdir())) # `srcnode()` must be used because `isdir()` doesn't work for entries in variant dirs which haven't been copied yet.
result_nodes.extend(self.Glob(f'{path}/{pattern}', ondisk=ondisk, source=source, strings=strings, exclude=exclude))
return sorted(result_nodes)
BaseEnvironment.RGlob = __RGlob
It tries imitate the standard Glob as closely as possible. The biggest difference is that beside the pattern is takes a root path as another argument. The pattern is then applied to this root path and every sub-directory in it.
This code adds function RGlob it to the base environment, which means you will be able to call it on every environment that is created after that. The best place to paste this is probably the file site_scons/site_init.py.

Answer 5

I use this:
srcdir = './'
sources = [s for s in glob2.glob(srcdir + '**/*.cpp') if "/." not in s]