Remove a lot of dead code in SConstruct

SConstruct

@@ -27,149 +27,40 @@ CFLAGS = '-Wall -Wextra -pedantic'
 # BUILD STUFF BELOW HERE
 #
 
-import os
-import os.path
-import SCons.Errors
+if not GetOption('build_cmds'):
+    def comstr(action):
+        return '{:>18}: $TARGET'.format(action)
+    default_env = DefaultEnvironment()
+    default_env['ARCOMSTR'] = comstr('Archiving')
+    default_env['ASCOMSTR'] = comstr('Assembling')
+    default_env['ASPPCOMSTR'] = comstr('Assembling')
+    default_env['CCCOMSTR'] = comstr('Building (C)')
+    default_env['CXXCOMSTR'] = comstr('Building (C++)')
+    default_env['LINKCOMSTR'] = comstr('Linking')
+    default_env['RANLIBCOMSTR'] = comstr('Indexing')
+    default_env['SHCCCOMSTR'] = comstr('Building (C)')
+    default_env['SHCXXCOMSTR'] = comstr('Building (C++)')
+    default_env['SHLINKCOMSTR'] = comstr('Linking (Shared)')
 
 
-def which(program):
-    def is_executable(path):
-        return os.path.exists(path) and os.access(path, os.X_OK)
-
-    path, name = os.path.split(program)
-    if path:
-        if is_executable(program):
-            return program
-    else:
-        pathext = [''] + os.environ.get('PATHEXT', '').split(os.pathsep)
-        for path in os.environ.get('PATH', '').split(os.pathsep):
-            exe = os.path.join(path, program)
-            for ext in pathext:
-                candidate = exe + ext
-                if is_executable(candidate):
-                    return candidate
-    return None
+#test_gtest_dir = Dir('#lib/gtest')
+#test_gtest_include = test_gtest_dir.Dir('include')
+#test_env = create_env('test', [src_dir, test_dir, test_gtest_dir], {
+#    'CPPDEFINES': ['DEBUG'],
+#    'CPPPATH': [test_gtest_include],
+#    'LIBPATH': [test_gtest_dir],
+#    'CFLAGS': debug_cflags,
+#    'CXXFLAGS': debug_cflags,
+#})
 
 
-def get_bool_argument(arg):
+for mode in GetOption('modes'):
     try:
-        return bool(int(arg))
-    except ValueError:
-        pass
-    if arg in ('False', 'FALSE', 'false', ''):
-        return False
-    return True
-
-
-def set_toolchain_binary(env, var, user_binary, binaries=()):
-    if user_binary and which(user_binary):
-        env[var] = user_binary
-        return
-    for c in binaries:
-        if which(c):
-            env[var] = c
-            break
-
-common_env = Environment()
-set_toolchain_binary(common_env, 'CC', CC, ('clang', 'gcc'))
-set_toolchain_binary(common_env, 'CXX', CXX, ('clang++', 'g++'))
-set_toolchain_binary(common_env, 'AS', AS)
-set_toolchain_binary(common_env, 'LINK', LINK)
-common_env.Append(CFLAGS='{} -std=c99'.format(CFLAGS))
-common_env.Append(CXXFLAGS='{} -std=c++11'.format(CFLAGS))
-
-# Add color error messages for clang
-if 'clang' in common_env['CC']:
-    common_env.Append(CFLAGS=' -fcolor-diagnostics')
-if 'clang' in common_env['CXX']:
-    common_env.Append(CXXFLAGS=' -fcolor-diagnostics')
-
-BUILD_CMDS = get_bool_argument(ARGUMENTS.get('BUILD_CMDS', False))
-if not BUILD_CMDS:
-    def generate_comstr(action):
-        return '{:>25}: $TARGET'.format(action)
-    common_env['ARCOMSTR'] = generate_comstr('Archiving')
-    common_env['ASCOMSTR'] = generate_comstr('Assembling')
-    common_env['ASPPCOMSTR'] = generate_comstr('Assembling')
-    common_env['CCCOMSTR'] = generate_comstr('Building (C)')
-    common_env['CXXCOMSTR'] = generate_comstr('Building (C++)')
-    common_env['LINKCOMSTR'] = generate_comstr('Linking')
-    common_env['RANLIBCOMSTR'] = generate_comstr('Indexing')
-    common_env['SHCCCOMSTR'] = generate_comstr('Building (C, Shared)')
-    common_env['SHCXXCOMSTR'] = generate_comstr('Building (C++, Shared)')
-    common_env['SHLINKCOMSTR'] = generate_comstr('Linking (Shared)')
-
-build_dir = Dir('#build')
-lib_dir = Dir('#lib')
-src_dir = Dir('#src')
-test_dir = Dir('#test')
-
-
-def create_env(name, src_dirs, appends=None):
-    output_dir = build_dir.Dir(name)
-    env = common_env.Clone()
-    env['__name'] = name
-    env['__build_dir'] = output_dir
-    env['__src_dirs'] = []
-    env['__output_dirs'] = []
-    for d in src_dirs:
-        out_dir = output_dir.Dir(d.path)
-        env['__src_dirs'].append(d)
-        env['__output_dirs'].append(out_dir)
-        env.VariantDir(out_dir, d.path, duplicate=0)
-        env.Clean('.', out_dir)
-    if appends:
-        for k, v in appends.iteritems():
-            if k.startswith('='):
-                env[k[1:]] = v
-            else:
-                env.Append(**{k: v})
-    return env
-
-
-debug_cflags = ' -O0 -g'
-debug_env = create_env('debug', [src_dir], {
-    'CPPDEFINES': ['DEBUG'],
-    'CFLAGS': debug_cflags,
-    'CXXFLAGS': debug_cflags,
-})
-
-release_cflags = ' -O2'
-release_env = create_env('release', [src_dir], {
-    'CPPDEFINES': ['RELEASE'],
-    'CFLAGS': release_cflags,
-    'CXXFLAGS': release_cflags,
-})
-
-test_gtest_dir = Dir('#lib/gtest')
-test_cpppath = test_gtest_dir.Dir('include')
-test_env = create_env('test', [src_dir, test_dir, test_gtest_dir], {
-    'CPPDEFINES': ['DEBUG'],
-    'CPPPATH': [test_cpppath],
-    'LIBPATH': [test_gtest_dir],
-    'CFLAGS': debug_cflags,
-    'CXXFLAGS': debug_cflags,
-})
-
-
-modes = {
-    'debug': debug_env,
-    'release': release_env,
-    'test': test_env,
-}
-
-mode = ARGUMENTS.get('MODE', None)
-build_modes = []
-if mode:
-    # If MODE=foo is specified, build only that mode.
-    build_modes.append(mode)
-else:
-    build_modes = modes.keys()
-
-for mode in build_modes:
-    try:
-        env = modes[mode]
+        env = MODES[mode]
     except KeyError:
         print 'Skipping invalid mode: {}'.format(mode)
-    for d in env['__output_dirs']:
-        env.SConscript(d.File('SConscript'), {'env': env})
+    library, binary = env.SConscript(SRC_DIR.File('SConscript'), {
+        'env': env
+    }, variant_dir=BUILD_DIR.Dir(env['MODE']).Dir('src'), duplicate=0)
+    env.Alias('lib', library)
+    env.Alias('bin', binary)

site_scons/.gitignore

@@ -0,0 +1 @@
+*.pyc

site_scons/binaries.py

@@ -0,0 +1,42 @@
+# files.py
+#
+# Utilities for working with files and paths in SCons.
+#
+# Eryn Wells <eryn@erynwells.me>
+
+import os
+
+
+def which(program):
+    '''
+    Given a program name, search the system environment's $PATH for a binary of
+    that name. If one exists, return its name. If not, return None. This
+    function will also use the system environment's $PATHEXT to find binaries
+    with appropriate extensions (i.e., .exe on Windows).
+    '''
+    is_executable = lambda path: (    os.path.exists(path)
+                                  and os.access(path, os.X_OK))
+
+    path, name = os.path.split(program)
+    if path:
+        if is_executable(program):
+            return program
+    else:
+        pathext = [''] + os.environ.get('PATHEXT', '').split(os.pathsep)
+        for path in os.environ.get('PATH', '').split(os.pathsep):
+            exe = os.path.join(path, program)
+            for ext in pathext:
+                candidate = exe + ext
+                if is_executable(candidate):
+                    return candidate
+    return None
+
+
+def first(binaries):
+    '''
+    Given a list of binaries, return the first one found.
+    '''
+    for binary in binaries:
+        if which(binary):
+            return binary
+    return None

site_scons/site_init.py

@@ -0,0 +1,72 @@
+# site_init.py
+#
+# This file is read before every SConstruct and SConscript. So, anything that
+# should be available to every build script should go here.
+#
+# Eryn Wells <eryn@erynwells.me>
+
+import os.path
+import SCons.Defaults
+import binaries
+
+
+BUILD_DIR = Dir('#build')
+LIB_DIR = Dir('#lib')
+SRC_DIR = Dir('#src')
+TEST_DIR = Dir('#test')
+
+#
+# Environment Configuration
+#
+
+def has_clang(env):
+    _, cc_tail = os.path.split(env['CC'])
+    _, cxx_tail = os.path.split(env['CXX'])
+    return any([cc_tail.startswith('clang'), cxx_tail.startswith('clang')])
+
+default_env = SCons.Defaults.DefaultEnvironment()
+default_env.Replace(CC=binaries.first(['clang', 'gcc']),
+                    CXX=binaries.first(['clang++', 'g++']))
+
+default_env.Append(CCFLAGS=['-Wall', '-Wextra', '-pedantic'],
+                   CFLAGS=['-std=c99'],
+                   CXXFLAGS=['-std=c++11'])
+if has_clang(default_env):
+    # Only clang supports color.
+    default_env.Append(CCFLAGS=['-fcolor-diagnostics'])
+
+
+debug_env = default_env.Clone(MODE='debug',
+                              CCFLAGS=['-O0', '-g'],
+                              CPPDEFINES=['DEBUG'])
+release_env = default_env.Clone(MODE='release',
+                                CCFLAGS=['-O2'],
+                                CPPDEFINES=['RELEASE'])
+
+MODES = {
+    'debug': debug_env,
+    'release': release_env
+}
+
+#
+# Command Line Options
+#
+
+def process_modes_option(option, opt, value, parser):
+    modes = value.split(',')
+    for m in modes:
+        setattr(parser.values, 'modes', set(modes))
+
+AddOption('--show-build-cmds',
+          dest='build_cmds',
+          action='store_true',
+          help='Show build commands instead of friendly build messages')
+AddOption('--modes',
+          type='string',
+          action='callback',
+          dest='modes',
+          metavar='MODES',
+          default=set(['debug']),
+          callback=process_modes_option,
+          help=('A comma separated list of modes. Choose from: {}. Default is '
+                'debug.').format(', '.join(MODES.keys())))