Use a Glob() in VariantDir() einvironment to find files recursively in Python?

Question

How can one make recursive Glob() in a VariantDir() environment in Python?

The answer from the question

Answer 1

I believe the accepted answer only works if your source directory is '.'.

Here is a working example where the source directory is src and the variant directory is build.

File layout

.
├── include
│   └── sum.h
├── SConstruct
└── src
    ├── dir
    │   └── sum.cpp
    └── main.cpp

Files

sum.h

#ifndef _SUM_H_
#define _SUM_H_

double sum(const double x, const double y);

#endif

main.cpp

#include 
#include 

using namespace std;

int main() {

    cout << "Sum of 1 and 2 = " << sum(1., 2.) << endl;
    return 0;
}

sum.cpp

#include 

double sum(const double x, const double y) {
    return x + y;
}

SConstruct

import os

def variantglob(env, pattern, ondisk=True, source=True, strings=False,
                recursive=False):
    matches = []
    for root, dirs, filenames in os.walk(env['SOURCE_DIR']):
        cwd = Dir(os.path.join(env['VARIANT_DIR'],
                               os.path.relpath(root, env['SOURCE_DIR'])))
        matches.extend(cwd.glob(pattern, ondisk, source, strings))
    return matches

# Create Build Environment
env = Environment()

# Customize Environment
env.Replace(VARIANT_DIR='build',
            SOURCE_DIR='src')
env.Append(CPPPATH=['include'])

# Setup Variant Directory
VariantDir(variant_dir=env['VARIANT_DIR'],
           src_dir=env['SOURCE_DIR'], duplicate=0)

# Build the executable
exe = env.Program(os.path.join(env['VARIANT_DIR'], 'example'),
                  variantglob(env, '*.cpp', recursive=True))

# Install the executable
Install('bin', exe)

Build

Just execute scons at the top level directory. This will create a build directory and drop all your temporaries there (variant directory), and it will then install the result of the build into the bin folder.

Run

Execute bin/example to see it work.

Note

This example was tested on linux.

Why It Works

When building with variant directories you have to specify the path to the source as though it were already sitting in the variant directory, but those directories may not exist yet. This glob function walks the source tree to construct the paths that will be in the variant directory, and then globs against those paths.