scons: Expose pkg-config in a simpler manner.

1 files changed, 76 insertions, 0 deletions

diff --git a/scons/custom.py b/scons/custom.py
index 029f99b9946..df7ac93bb00 100644
--- a/scons/custom.py
+++ b/scons/custom.py
@@ -33,6 +33,8 @@ Custom builders and methods.
 import os
 import os.path
 import re
+import sys
+import subprocess
 
 import SCons.Action
 import SCons.Builder
@@ -154,6 +156,79 @@ def createCodeGenerateMethod(env):
     env.AddMethod(code_generate, 'CodeGenerate')
 
 
+def _pkg_check_modules(env, name, modules):
+    '''Simple wrapper for pkg-config.'''
+
+    env['HAVE_' + name] = False
+
+    # For backwards compatability
+    env[name.lower()] = False
+
+    if env['platform'] == 'windows':
+        return
+
+    if not env.Detect('pkg-config'):
+        return
+
+    if subprocess.call(["pkg-config", "--exists", ' '.join(modules)]) != 0:
+        return
+
+    # Other flags may affect the compilation of unrelated targets, so store
+    # them with a prefix, (e.g., XXX_CFLAGS, XXX_LIBS, etc)
+    try:
+        flags = env.ParseFlags('!pkg-config --cflags --libs ' + ' '.join(modules))
+    except OSError:
+        return
+    prefix = name + '_'
+    for flag_name, flag_value in flags.iteritems():
+        assert '_' not in flag_name
+        env[prefix + flag_name] = flag_value
+
+    env['HAVE_' + name] = True
+
+def pkg_check_modules(env, name, modules):
+
+    sys.stdout.write('Checking for %s...' % name)
+    _pkg_check_modules(env, name, modules)
+    result = env['HAVE_' + name]
+    sys.stdout.write(' %s\n' % ['no', 'yes'][int(bool(result))])
+
+    # XXX: For backwards compatability
+    env[name.lower()] = result
+
+
+def pkg_use_modules(env, names):
+    '''Search for all environment flags that match NAME_FOO and append them to
+    the FOO environment variable.'''
+
+    names = env.Flatten(names)
+
+    for name in names:
+        prefix = name + '_'
+
+        if not 'HAVE_' + name in env:
+            print 'Attempt to use unknown module %s' % name
+            env.Exit(1)
+
+        if not env['HAVE_' + name]:
+            print 'Attempt to use unavailable module %s' % name
+            env.Exit(1)
+
+        flags = {}
+        for flag_name, flag_value in env.Dictionary().iteritems():
+            if flag_name.startswith(prefix):
+                flag_name = flag_name[len(prefix):]
+                if '_' not in flag_name:
+                    flags[flag_name] = flag_value
+        if flags:
+            env.MergeFlags(flags)
+
+
+def createPkgConfigMethods(env):
+    env.AddMethod(pkg_check_modules, 'PkgCheckModules')
+    env.AddMethod(pkg_use_modules, 'PkgUseModules')
+
+
 def generate(env):
     """Common environment generation code"""
 
@@ -164,6 +239,7 @@ def generate(env):
     # Custom builders and methods
     createConvenienceLibBuilder(env)
     createCodeGenerateMethod(env)
+    createPkgConfigMethods(env)
 
     # for debugging
     #print env.Dump()