Build library objects in the SConscript variant_dir.

SCons has a feature that lets you declare a repository-root absolute
path to a file (e.g. "#lib/soundtouch/..."). Using this feature
prevents SCons from automatically re-directing built artifacts to a
variant_dir. To work around this, this commit moves src/SConscript and
src/SConscript.env to the root, and changes all paths in SConscripts
to use SConscript-relative paths.

This commit also switches to building an explicit static library for
vamp-hostdk, vamp-sdk, and soundtouch when internal linking is enabled
and the VAMP plugin now uses the system soundtouch if it is present.

Fixes Bug #1191327 and Bug #1617802.

1 files changed, 155 insertions, 0 deletions

diff --git a/SConscript.env b/SConscript.env
new file mode 100644
index 0000000000..2ced2f7245
--- /dev/null
+++ b/SConscript.env
@@ -0,0 +1,155 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+import sys, os, platform
+import SCons
+import SCons.Script
+import logging
+import fnmatch
+import shutil
+
+from build import util, mixxx, depends
+
+print('SConscript.env cwd: ' + os.getcwd())
+Import('build')
+
+# Grab the created environment from the MixxxBuild
+env = build.env
+
+# We are in the variant_dir (win|mac|lin)XX_build, and the 'src' subdirectory
+# may not exist yet.
+try:
+    os.mkdir('src')
+except:
+    pass
+
+# TODO(rryan): This logic should be written in a more SCons-friendly way, since
+# it depends on the cwd being the variant_dir to work properly.
+if os.path.exists('../build.h'):
+    # If a build.h exists in the project root mixxx/ directory then use that
+    # instead of writing our own. This is mostly since when we build Debian
+    # packages we don't have any of the Git metadata so we can't write one
+    # ourselves.
+    shutil.copy('../build.h', 'src/build.h')
+else:
+    util.write_build_header('src/build.h')
+
+conf = Configure(env, custom_tests = { 'CheckForPKGConfig' : util.CheckForPKGConfig,
+                                       'CheckForPKG' : util.CheckForPKG })
+
+if not conf.CheckCXX():
+    print("Building with CXX: %s" % env['CXX'])
+    print("A compiler with C++11 support is required.")
+    Exit(1)
+
+available_features = [depends.MixxxCore]
+extra_features = build.get_features()
+available_features.extend(extra_features)
+
+# Instantiate the features
+available_features = [feature_class() for feature_class in available_features]
+
+visited_dependencies = set()
+active_dependencies = []
+unmet_dependencies = False
+# Don't configure if the user is askign for help or a clean.
+should_configure = not GetOption('help') and not GetOption('clean')
+if not should_configure:
+    print('Skipping dependency configuration.')
+
+def visit_dependency(dependency_class, build, conf):
+    """Recursively configure all dependencies.
+
+    Skip over dependencies we have already setup.
+    """
+    global unmet_dependencies
+
+    if dependency_class in visited_dependencies:
+        return
+    visited_dependencies.add(dependency_class)
+    dependency = dependency_class()
+
+    try:
+        if should_configure:
+            print("Configuring %s" % dependency.name)
+            dependency.configure(build, conf)
+    except Exception as e:
+        logging.error("Unmet dependency: %s" % e)
+        unmet_dependencies = True
+    active_dependencies.append(dependency)
+
+    for sub_dependency in dependency.depends(build):
+        visit_dependency(sub_dependency, build, conf)
+
+for feature in available_features:
+    try:
+        if should_configure:
+            print("Configuring %s" % feature.name)
+            feature.configure(build, conf)
+
+        # Only process the feature's dependencies if it's enabled
+        if feature.enabled(build):
+            active_dependencies.append(feature)
+            for dependency in feature.depends(build):
+                visit_dependency(dependency, build, conf)
+    except Exception as e:
+        logging.error("Unmet dependency: %s" % e)
+        unmet_dependencies = True
+
+if unmet_dependencies:
+    logging.error("Build had unmet dependencies. Exiting.")
+    Exit(1)
+
+sources = []
+
+# Query each active dependency for sources they require
+for dependency in active_dependencies:
+    dep_sources = dependency.sources(build)
+    if dep_sources is not None:
+        sources.extend(dep_sources)
+    # If there's additional env variables that need to be set after the
+    # configure checks have run, then we'll take care of that now.
+    dependency.post_dependency_check_configure(build, conf)
+
+env = conf.Finish()
+
+#Tell SCons to build libraries that are bundled with Mixxx
+#===================================================
+
+print("Features Summary:")
+print("================")
+
+for feature in available_features:
+    message = "Enabled" if feature.enabled(build) else "Disabled"
+
+    # If the plugin has a status message, show it instead
+    if len(feature.status) > 0:
+        message = "%s" % feature.status
+
+    print("%035s... %s" % (feature.description(), message))
+
+build_flags = ' '.join(sorted(
+    [('%s=%s' % (k,v) if v is not None else k) for k,v in build.flags.items() if v is not None]))
+
+### Put flags info into a file
+with open("src/build.h", "a") as f:
+    f.write('#define BUILD_FLAGS "' + build_flags + '"\n')
+
+# Print the build flags. This is useful if the flags have been cached,
+# ie. if you just run "scons" and want to see the flags that you used last time.
+print("================")
+print("Building with flags: %s" % build_flags)
+print("Building with CC: %s" % env['CC'])
+print("Building with CXX: %s" % env['CXX'])
+print("Building with CCFLAGS: %s" % env['CCFLAGS'])
+print("Building with CPPDEFINES: %s" % ' '.join(['-D'+'='.join(pair) if not isinstance(pair, str) else '-D'+pair for pair in env['CPPDEFINES']]))
+print("Building with CXXFLAGS: %s" % env['CXXFLAGS'])
+print("Building with LINKFLAGS: %s" % env['LINKFLAGS'])
+print("Building with LIBS: %s" % ' '.join(env['LIBS']))
+print("Building with PATH: %s" % env['ENV']['PATH'])
+if build.platform_is_windows:
+    print("Building with INCLUDE: %s" % env['ENV']['INCLUDE'])
+    print("Building with LIB: %s" % env['ENV']['LIB'])
+    print("Building with LIBPATH: %s" % env['ENV']['LIBPATH'])
+print("================")
+
+Export('sources')