diff --git a/.wafupdaterc b/.wafupdaterc
index 34101435..b595a242 100755
--- a/.wafupdaterc
+++ b/.wafupdaterc
@@ -47,6 +47,7 @@ WAFLIB_STRIP_EXTRAS="
     boo
     boost
     c_dumbpreproc
+    c_emscripten
     cabal
     cfg_altoptions
     cfg_cross_gnu
diff --git a/waf b/waf
index 5ac0bcfc..e89e7594 100755
--- a/waf
+++ b/waf
@@ -32,7 +32,7 @@ POSSIBILITY OF SUCH DAMAGE.
 
 import os, sys, inspect
 
-VERSION="1.8.9"
+VERSION="1.8.14"
 REVISION="x"
 GIT="x"
 INSTALL="x"
diff --git a/waflib/Build.py b/waflib/Build.py
index fdd59fb0..154e5c8c 100644
--- a/waflib/Build.py
+++ b/waflib/Build.py
@@ -1015,6 +1015,7 @@ class InstallContext(BuildContext):
 			if tsk.runnable_status() == Task.ASK_LATER:
 				raise self.WafError('cannot post the task %r' % tsk)
 			tsk.run()
+			tsk.hasrun = True
 
 	def install_files(self, dest, files, env=None, chmod=Utils.O644, relative_trick=False, cwd=None, add=True, postpone=True, task=None):
 		"""
diff --git a/waflib/ConfigSet.py b/waflib/ConfigSet.py
index de0c3aee..2fac2166 100644
--- a/waflib/ConfigSet.py
+++ b/waflib/ConfigSet.py
@@ -167,6 +167,7 @@ class ConfigSet(object):
 			for x in keys:
 				tbl[x] = copy.deepcopy(tbl[x])
 			self.table = tbl
+		return self
 
 	def get_flat(self, key):
 		"""
diff --git a/waflib/Configure.py b/waflib/Configure.py
index 1433336d..88468d23 100644
--- a/waflib/Configure.py
+++ b/waflib/Configure.py
@@ -192,11 +192,11 @@ class ConfigurationContext(Context.Context):
 		env['files'] = self.files
 		env['environ'] = dict(self.environ)
 
-		if not self.env.NO_LOCK_IN_RUN:
+		if not self.env.NO_LOCK_IN_RUN and not getattr(Options.options, 'no_lock_in_run'):
 			env.store(os.path.join(Context.run_dir, Options.lockfile))
-		if not self.env.NO_LOCK_IN_TOP:
+		if not self.env.NO_LOCK_IN_TOP and not getattr(Options.options, 'no_lock_in_top'):
 			env.store(os.path.join(Context.top_dir, Options.lockfile))
-		if not self.env.NO_LOCK_IN_OUT:
+		if not self.env.NO_LOCK_IN_OUT and not getattr(Options.options, 'no_lock_in_out'):
 			env.store(os.path.join(Context.out_dir, Options.lockfile))
 
 	def prepare_env(self, env):
@@ -234,7 +234,7 @@ class ConfigurationContext(Context.Context):
 			tmpenv = self.all_envs[key]
 			tmpenv.store(os.path.join(self.cachedir.abspath(), key + Build.CACHE_SUFFIX))
 
-	def load(self, input, tooldir=None, funs=None):
+	def load(self, input, tooldir=None, funs=None, with_sys_path=True):
 		"""
 		Load Waf tools, which will be imported whenever a build is started.
 
@@ -252,7 +252,7 @@ class ConfigurationContext(Context.Context):
 			# avoid loading the same tool more than once with the same functions
 			# used by composite projects
 
-			mag = (tool, id(self.env), funs)
+			mag = (tool, id(self.env), tooldir, funs)
 			if mag in self.tool_cache:
 				self.to_log('(tool %s is already loaded, skipping)' % tool)
 				continue
@@ -260,7 +260,7 @@ class ConfigurationContext(Context.Context):
 
 			module = None
 			try:
-				module = Context.load_tool(tool, tooldir, ctx=self)
+				module = Context.load_tool(tool, tooldir, ctx=self, with_sys_path=with_sys_path)
 			except ImportError as e:
 				self.fatal('Could not load the Waf tool %r from %r\n%s' % (tool, sys.path, e))
 			except Exception as e:
@@ -352,7 +352,7 @@ def conf(f):
 	return f
 
 @conf
-def add_os_flags(self, var, dest=None):
+def add_os_flags(self, var, dest=None, dup=True):
 	"""
 	Import operating system environment values into ``conf.env`` dict::
 
@@ -363,10 +363,16 @@ def add_os_flags(self, var, dest=None):
 	:type var: string
 	:param dest: destination variable, by default the same as var
 	:type dest: string
+	:param dup: add the same set of flags again
+	:type dup: bool
 	"""
-	# do not use 'get' to make certain the variable is not defined
-	try: self.env.append_value(dest or var, shlex.split(self.environ[var]))
-	except KeyError: pass
+	try:
+		flags = shlex.split(self.environ[var])
+	except KeyError:
+		return
+	# TODO: in waf 1.9, make dup=False the default
+	if dup or ''.join(flags) not in ''.join(Utils.to_list(self.env[dest or var])):
+		self.env.append_value(dest or var, flags)
 
 @conf
 def cmd_to_list(self, cmd):
diff --git a/waflib/Context.py b/waflib/Context.py
index cb5e59b8..70cef85c 100644
--- a/waflib/Context.py
+++ b/waflib/Context.py
@@ -11,13 +11,13 @@ from waflib import Utils, Errors, Logs
 import waflib.Node
 
 # the following 3 constants are updated on each new release (do not touch)
-HEXVERSION=0x1080900
+HEXVERSION=0x1080e00
 """Constant updated on new releases"""
 
-WAFVERSION="1.8.9"
+WAFVERSION="1.8.14"
 """Constant updated on new releases"""
 
-WAFREVISION="06e49b2a82166aeb14dde8357c58387f252fc722"
+WAFREVISION="ce8234c396bb246a20ea9f51594ee051d5b378e7"
 """Git revision when the waf version is updated"""
 
 ABI = 98
@@ -55,7 +55,7 @@ waf_dir = ''
 
 local_repo = ''
 """Local repository containing additional Waf tools (plugins)"""
-remote_repo = 'http://waf.googlecode.com/git/'
+remote_repo = 'https://raw.githubusercontent.com/waf-project/waf/master/'
 """
 Remote directory containing downloadable waf tools. The missing tools can be downloaded by using::
 
@@ -210,9 +210,10 @@ class Context(ctx):
 		"""
 		tools = Utils.to_list(tool_list)
 		path = Utils.to_list(kw.get('tooldir', ''))
+		with_sys_path = kw.get('with_sys_path', True)
 
 		for t in tools:
-			module = load_tool(t, path)
+			module = load_tool(t, path, with_sys_path=with_sys_path)
 			fun = getattr(module, kw.get('name', self.fun), None)
 			if fun:
 				fun(self)
@@ -321,11 +322,11 @@ class Context(ctx):
 		unlike :py:meth:`waflib.Context.Context.cmd_and_log`
 
 		:param cmd: command argument for subprocess.Popen
-		:param kw: keyword arguments for subprocess.Popen
+		:param kw: keyword arguments for subprocess.Popen. The parameters input/timeout will be passed to wait/communicate.
 		"""
 		subprocess = Utils.subprocess
 		kw['shell'] = isinstance(cmd, str)
-		Logs.debug('runner: %r' % cmd)
+		Logs.debug('runner: %r' % (cmd,))
 		Logs.debug('runner_env: kw=%s' % kw)
 
 		if self.logger:
@@ -339,14 +340,25 @@ class Context(ctx):
 		if Logs.verbose and not kw['shell'] and not Utils.check_exe(cmd[0]):
 			raise Errors.WafError("Program %s not found!" % cmd[0])
 
+		wargs = {}
+		if 'timeout' in kw:
+			if kw['timeout'] is not None:
+				wargs['timeout'] = kw['timeout']
+			del kw['timeout']
+		if 'input' in kw:
+			if kw['input']:
+				wargs['input'] = kw['input']
+				kw['stdin'] = Utils.subprocess.PIPE
+			del kw['input']
+
 		try:
 			if kw['stdout'] or kw['stderr']:
 				p = subprocess.Popen(cmd, **kw)
-				(out, err) = p.communicate()
+				(out, err) = p.communicate(**wargs)
 				ret = p.returncode
 			else:
 				out, err = (None, None)
-				ret = subprocess.Popen(cmd, **kw).wait()
+				ret = subprocess.Popen(cmd, **kw).wait(**wargs)
 		except Exception as e:
 			raise Errors.WafError('Execution failure: %s' % str(e), ex=e)
 
@@ -369,24 +381,25 @@ class Context(ctx):
 
 	def cmd_and_log(self, cmd, **kw):
 		"""
-		Execute a command and return stdout if the execution is successful.
+		Execute a command and return stdout/stderr if the execution is successful.
 		An exception is thrown when the exit status is non-0. In that case, both stderr and stdout
 		will be bound to the WafError object::
 
 			def configure(conf):
 				out = conf.cmd_and_log(['echo', 'hello'], output=waflib.Context.STDOUT, quiet=waflib.Context.BOTH)
 				(out, err) = conf.cmd_and_log(['echo', 'hello'], output=waflib.Context.BOTH)
+				(out, err) = conf.cmd_and_log(cmd, input='\\n'.encode(), output=waflib.Context.STDOUT)
 				try:
 					conf.cmd_and_log(['which', 'someapp'], output=waflib.Context.BOTH)
 				except Exception as e:
 					print(e.stdout, e.stderr)
 
 		:param cmd: args for subprocess.Popen
-		:param kw: keyword arguments for subprocess.Popen
+		:param kw: keyword arguments for subprocess.Popen. The parameters input/timeout will be passed to wait/communicate.
 		"""
 		subprocess = Utils.subprocess
 		kw['shell'] = isinstance(cmd, str)
-		Logs.debug('runner: %r' % cmd)
+		Logs.debug('runner: %r' % (cmd,))
 
 		if 'quiet' in kw:
 			quiet = kw['quiet']
@@ -406,9 +419,21 @@ class Context(ctx):
 		kw['stdout'] = kw['stderr'] = subprocess.PIPE
 		if quiet is None:
 			self.to_log(cmd)
+
+		wargs = {}
+		if 'timeout' in kw:
+			if kw['timeout'] is not None:
+				wargs['timeout'] = kw['timeout']
+			del kw['timeout']
+		if 'input' in kw:
+			if kw['input']:
+				wargs['input'] = kw['input']
+				kw['stdin'] = Utils.subprocess.PIPE
+			del kw['input']
+
 		try:
 			p = subprocess.Popen(cmd, **kw)
-			(out, err) = p.communicate()
+			(out, err) = p.communicate(**wargs)
 		except Exception as e:
 			raise Errors.WafError('Execution failure: %s' % str(e), ex=e)
 
@@ -620,14 +645,14 @@ def load_module(path, encoding=None):
 	module_dir = os.path.dirname(path)
 	sys.path.insert(0, module_dir)
 
-	exec(compile(code, path, 'exec'), module.__dict__)
-	sys.path.remove(module_dir)
+	try    : exec(compile(code, path, 'exec'), module.__dict__)
+	finally: sys.path.remove(module_dir)
 
 	cache_modules[path] = module
 
 	return module
 
-def load_tool(tool, tooldir=None, ctx=None):
+def load_tool(tool, tooldir=None, ctx=None, with_sys_path=True):
 	"""
 	Import a Waf tool (python module), and store it in the dict :py:const:`waflib.Context.Context.tools`
 
@@ -635,33 +660,44 @@ def load_tool(tool, tooldir=None, ctx=None):
 	:param tool: Name of the tool
 	:type  tooldir: list
 	:param tooldir: List of directories to search for the tool module
+	:type  with_sys_path: boolean
+	:param with_sys_path: whether or not to search the regular sys.path, besides waf_dir and potentially given tooldirs
 	"""
 	if tool == 'java':
 		tool = 'javaw' # jython
 	else:
 		tool = tool.replace('++', 'xx')
 
-	if tooldir:
-		assert isinstance(tooldir, list)
-		sys.path = tooldir + sys.path
-		try:
-			__import__(tool)
+	origSysPath = sys.path
+	if not with_sys_path: sys.path = []
+	try:
+		if tooldir:
+			assert isinstance(tooldir, list)
+			sys.path = tooldir + sys.path
+			try:
+				__import__(tool)
+			finally:
+				for d in tooldir:
+					sys.path.remove(d)
 			ret = sys.modules[tool]
 			Context.tools[tool] = ret
 			return ret
-		finally:
-			for d in tooldir:
-				sys.path.remove(d)
-	else:
-		for x in ('waflib.Tools.%s', 'waflib.extras.%s', 'waflib.%s', '%s'):
+		else:
+			if not with_sys_path: sys.path.insert(0, waf_dir)
 			try:
-				__import__(x % tool)
-				break
-			except ImportError:
-				x = None
-		if x is None: # raise an exception
-			__import__(tool)
-		ret = sys.modules[x % tool]
-		Context.tools[tool] = ret
-		return ret
+				for x in ('waflib.Tools.%s', 'waflib.extras.%s', 'waflib.%s', '%s'):
+					try:
+						__import__(x % tool)
+						break
+					except ImportError:
+						x = None
+				if x is None: # raise an exception
+					__import__(tool)
+			finally:
+				if not with_sys_path: sys.path.remove(waf_dir)
+			ret = sys.modules[x % tool]
+			Context.tools[tool] = ret
+			return ret
+	finally:
+		if not with_sys_path: sys.path += origSysPath
 
diff --git a/waflib/Logs.py b/waflib/Logs.py
index a8807199..8dd2af92 100644
--- a/waflib/Logs.py
+++ b/waflib/Logs.py
@@ -20,8 +20,8 @@ if not os.environ.get('NOSYNC', False):
 # in case someone uses the root logger
 import logging
 
-LOG_FORMAT = "%(asctime)s %(c1)s%(zone)s%(c2)s %(message)s"
-HOUR_FORMAT = "%H:%M:%S"
+LOG_FORMAT = os.environ.get('WAF_LOG_FORMAT', '%(asctime)s %(c1)s%(zone)s%(c2)s %(message)s')
+HOUR_FORMAT = os.environ.get('WAF_HOUR_FORMAT', '%H:%M:%S')
 
 zones = ''
 verbose = 0
@@ -35,6 +35,7 @@ colors_lst = {
 'PINK'  :'\x1b[35m',
 'BLUE'  :'\x1b[01;34m',
 'CYAN'  :'\x1b[36m',
+'GREY'  :'\x1b[37m',
 'NORMAL':'\x1b[0m',
 'cursor_on'  :'\x1b[?25h',
 'cursor_off' :'\x1b[?25l',
diff --git a/waflib/Options.py b/waflib/Options.py
index ad6a44ff..f11fe3e3 100644
--- a/waflib/Options.py
+++ b/waflib/Options.py
@@ -126,6 +126,10 @@ class OptionsContext(Context.Context):
 		gr.add_option('-o', '--out', action='store', default='', help='build dir for the project', dest='out')
 		gr.add_option('-t', '--top', action='store', default='', help='src dir for the project', dest='top')
 
+		gr.add_option('--no-lock-in-run', action='store_true', default='', help=optparse.SUPPRESS_HELP, dest='no_lock_in_run')
+		gr.add_option('--no-lock-in-out', action='store_true', default='', help=optparse.SUPPRESS_HELP, dest='no_lock_in_out')
+		gr.add_option('--no-lock-in-top', action='store_true', default='', help=optparse.SUPPRESS_HELP, dest='no_lock_in_top')
+
 		default_prefix = getattr(Context.g_module, 'default_prefix', os.environ.get('PREFIX'))
 		if not default_prefix:
 			if platform == 'win32':
diff --git a/waflib/Scripting.py b/waflib/Scripting.py
index 4a78557c..832e3573 100644
--- a/waflib/Scripting.py
+++ b/waflib/Scripting.py
@@ -61,10 +61,17 @@ def waf_entry_point(current_directory, version, wafdir):
 					no_climb = True
 					break
 
+	# if --top is provided assume the build started in the top directory
+	for x in sys.argv:
+		if x.startswith('--top='):
+			Context.run_dir = Context.top_dir = x[6:]
+		if x.startswith('--out='):
+			Context.out_dir = x[6:]
+
 	# try to find a lock file (if the project was configured)
 	# at the same time, store the first wscript file seen
 	cur = current_directory
-	while cur:
+	while cur and not Context.top_dir:
 		lst = os.listdir(cur)
 		if Options.lockfile in lst:
 			env = ConfigSet.ConfigSet()
@@ -557,16 +564,26 @@ def distcheck(ctx):
 	pass
 
 def update(ctx):
-	'''updates the plugins from the *waflib/extras* directory'''
-	lst = Options.options.files.split(',')
-	if not lst:
-		lst = [x for x in Utils.listdir(Context.waf_dir + '/waflib/extras') if x.endswith('.py')]
+	lst = Options.options.files
+	if lst:
+		lst = lst.split(',')
+	else:
+		path = os.path.join(Context.waf_dir, 'waflib', 'extras')
+		lst = [x for x in Utils.listdir(path) if x.endswith('.py')]
 	for x in lst:
 		tool = x.replace('.py', '')
+		if not tool:
+			continue
+		try:
+			dl = Configure.download_tool
+		except AttributeError:
+			ctx.fatal('The command "update" is dangerous; include the tool "use_config" in your project!')
 		try:
-			Configure.download_tool(tool, force=True, ctx=ctx)
+			dl(tool, force=True, ctx=ctx)
 		except Errors.WafError:
-			Logs.error('Could not find the tool %s in the remote repository' % x)
+			Logs.error('Could not find the tool %r in the remote repository' % x)
+		else:
+			Logs.warn('Updated %r' % tool)
 
 def autoconfigure(execute_method):
 	"""
diff --git a/waflib/Task.py b/waflib/Task.py
index b70532e5..326ac303 100644
--- a/waflib/Task.py
+++ b/waflib/Task.py
@@ -64,7 +64,7 @@ def f(tsk):
 '''
 
 classes = {}
-"class tasks created by user scripts or Waf tools are kept in this dict name -> class object"
+"Class tasks created by user scripts or Waf tools (maps names to class objects). Task classes defined in Waf tools are registered here through the metaclass :py:class:`waflib.Task.store_task_type`."
 
 class store_task_type(type):
 	"""
@@ -118,6 +118,8 @@ class TaskBase(evil):
 	#. runnable_status: ask the task if it should be run, skipped, or if we have to ask later
 	#. run: let threads execute the task
 	#. post_run: let threads update the data regarding the task (cache)
+
+	.. warning:: For backward compatibility reasons, the suffix "_task" is truncated in derived class names. This limitation will be removed in Waf 1.9.
 	"""
 
 	color = 'GREEN'
@@ -402,6 +404,8 @@ class Task(TaskBase):
 	uses a hash value (from :py:class:`waflib.Task.Task.signature`) which is persistent from build to build. When the value changes,
 	the task has to be executed. The method :py:class:`waflib.Task.Task.post_run` will assign the task signature to the output
 	nodes (if present).
+
+	.. warning:: For backward compatibility reasons, the suffix "_task" is truncated in derived class names. This limitation will be removed in Waf 1.9.
 	"""
 	vars = []
 	"""Variables to depend on (class attribute used for :py:meth:`waflib.Task.Task.sig_vars`)"""
diff --git a/waflib/TaskGen.py b/waflib/TaskGen.py
index b1110080..44aa25d5 100644
--- a/waflib/TaskGen.py
+++ b/waflib/TaskGen.py
@@ -593,6 +593,12 @@ def process_rule(self):
 		if getattr(self, 'cache_rule', 'True'):
 			cache[(name, self.rule)] = cls
 
+		if getattr(self, 'cls_str', None):
+			setattr(cls, '__str__', self.cls_str)
+
+		if getattr(self, 'cls_keyword', None):
+			setattr(cls, 'keyword', self.cls_keyword)
+
 	# now create one instance
 	tsk = self.create_task(name)
 
diff --git a/waflib/Tools/c_aliases.py b/waflib/Tools/c_aliases.py
index 65677801..4bb6352e 100644
--- a/waflib/Tools/c_aliases.py
+++ b/waflib/Tools/c_aliases.py
@@ -1,11 +1,11 @@
 #!/usr/bin/env python
 # encoding: utf-8
-# Thomas Nagy, 2005-2010 (ita)
+# Thomas Nagy, 2005-2015 (ita)
 
 "base for all c/c++ programs and libraries"
 
 import os, sys, re
-from waflib import Utils, Build
+from waflib import Utils, Build, Errors
 from waflib.Configure import conf
 
 def get_extensions(lst):
@@ -44,26 +44,34 @@ def sniff_features(**kw):
 	feats = []
 
 	# watch the order, cxx will have the precedence
-	if 'cxx' in exts or 'cpp' in exts or 'c++' in exts or 'cc' in exts or 'C' in exts:
-		feats.append('cxx')
+	for x in 'cxx cpp c++ cc C'.split():
+		if x in exts:
+			feats.append('cxx')
+			break
 
 	if 'c' in exts or 'vala' in exts:
 		feats.append('c')
 
+	for x in 'f f90 F F90 for FOR'.split():
+		if x in exts:
+			feats.append('fc')
+			break
+
 	if 'd' in exts:
 		feats.append('d')
 
 	if 'java' in exts:
 		feats.append('java')
-
-	if 'java' in exts:
 		return 'java'
 
 	if type in ('program', 'shlib', 'stlib'):
+		will_link = False
 		for x in feats:
-			if x in ('cxx', 'd', 'c'):
+			if x in ('cxx', 'd', 'fc', 'c'):
 				feats.append(x + type)
-
+				will_link = True
+		if not will_link and not kw.get('features', []):
+			raise Errors.WafError('Cannot link from %r, try passing eg: features="cprogram"?' % kw)
 	return feats
 
 def set_features(kw, _type):
diff --git a/waflib/Tools/c_config.py b/waflib/Tools/c_config.py
old mode 100755
new mode 100644
index e9c22204..14243cd8
--- a/waflib/Tools/c_config.py
+++ b/waflib/Tools/c_config.py
@@ -25,10 +25,10 @@ cfg_ver = {
 
 SNIP_FUNCTION = '''
 int main(int argc, char **argv) {
-	void *p;
+	void (*p)();
 	(void)argc; (void)argv;
-	p=(void*)(%s);
-	return (int)p;
+	p=(void(*)())(%s);
+	return !p;
 }
 '''
 """Code template for checking for functions"""
@@ -383,7 +383,9 @@ def check_cfg(self, *k, **kw):
 			conf.check_cfg(path='sdl-config', args='--cflags --libs', package='', uselib_store='SDL')
 			conf.check_cfg(path='mpicc', args='--showme:compile --showme:link',
 				package='', uselib_store='OPEN_MPI', mandatory=False)
-
+			# variables
+			conf.check_cfg(package='gtk+-2.0', variables=['includedir', 'prefix'], uselib_store='FOO')
+			print(conf.env.FOO_includedir)
 	"""
 	if k:
 		lst = k[0].split()
@@ -587,6 +589,7 @@ def validate_c(self, kw):
 		kw['execute'] = False
 	if kw['execute']:
 		kw['features'].append('test_exec')
+		kw['chmod'] = 493
 
 	if not 'errmsg' in kw:
 		kw['errmsg'] = 'not found'
@@ -661,6 +664,16 @@ def check(self, *k, **kw):
 	Perform a configuration test by calling :py:func:`waflib.Configure.run_build`.
 	For the complete list of parameters, see :py:func:`waflib.Tools.c_config.validate_c`.
 	To force a specific compiler, pass "compiler='c'" or "compiler='cxx'" in the arguments
+
+	Besides build targets, complete builds can be given though a build function. All files will
+	be written to a temporary directory::
+
+		def build(bld):
+			lib_node = bld.srcnode.make_node('libdir/liblc1.c')
+			lib_node.parent.mkdir()
+			lib_node.write('#include <stdio.h>\\nint lib_func(void) { FILE *f = fopen("foo", "r");}\\n', 'w')
+			bld(features='c cshlib', source=[lib_node], linkflags=conf.env.EXTRA_LDFLAGS, target='liblc')
+		conf.check(build_fun=build, msg=msg)
 	"""
 	self.validate_c(kw)
 	self.start_msg(kw['msg'], **kw)
@@ -855,7 +868,10 @@ def write_config_header(self, configfile='', guard='', top=False, defines=True,
 			cnf.define('A', 1)
 			cnf.write_config_header('config.h')
 
-	:param configfile: relative path to the file to create
+	This function only adds include guards (if necessary), consult
+	:py:func:`waflib.Tools.c_config.get_config_header` for details on the body.
+
+	:param configfile: path to the file to create (relative or absolute)
 	:type configfile: string
 	:param guard: include guard name to add, by default it is computed from the file name
 	:type guard: string
@@ -884,7 +900,7 @@ def write_config_header(self, configfile='', guard='', top=False, defines=True,
 
 	node.write('\n'.join(lst))
 
-	# config files are not removed on "waf clean"
+	# config files must not be removed on "waf clean"
 	self.env.append_unique(Build.CFG_FILES, [node.abspath()])
 
 	if remove:
@@ -898,9 +914,16 @@ def get_config_header(self, defines=True, headers=False, define_prefix=''):
 	Create the contents of a ``config.h`` file from the defines and includes
 	set in conf.env.define_key / conf.env.include_key. No include guards are added.
 
+	A prelude will be added from the variable env.WAF_CONFIG_H_PRELUDE if provided. This
+	can be used to insert complex macros or include guards::
+
+		def configure(conf):
+			conf.env.WAF_CONFIG_H_PRELUDE = '#include <unistd.h>\\n'
+			conf.write_config_header('config.h')
+
 	:param defines: write the defines values
 	:type defines: bool
-	:param headers: write the headers
+	:param headers: write include entries for each element in self.env.INCKEYS
 	:type headers: bool
 	:type define_prefix: string
 	:param define_prefix: prefix all the defines with a particular prefix
@@ -908,6 +931,10 @@ def get_config_header(self, defines=True, headers=False, define_prefix=''):
 	:rtype: string
 	"""
 	lst = []
+
+	if self.env.WAF_CONFIG_H_PRELUDE:
+		lst.append(self.env.WAF_CONFIG_H_PRELUDE)
+
 	if headers:
 		for x in self.env[INCKEYS]:
 			lst.append('#include <%s>' % x)
@@ -931,24 +958,24 @@ def cc_add_flags(conf):
 	"""
 	Add CFLAGS / CPPFLAGS from os.environ to conf.env
 	"""
-	conf.add_os_flags('CPPFLAGS', 'CFLAGS')
-	conf.add_os_flags('CFLAGS')
+	conf.add_os_flags('CPPFLAGS', dup=False)
+	conf.add_os_flags('CFLAGS', dup=False)
 
 @conf
 def cxx_add_flags(conf):
 	"""
 	Add CXXFLAGS / CPPFLAGS from os.environ to conf.env
 	"""
-	conf.add_os_flags('CPPFLAGS', 'CXXFLAGS')
-	conf.add_os_flags('CXXFLAGS')
+	conf.add_os_flags('CPPFLAGS', dup=False)
+	conf.add_os_flags('CXXFLAGS', dup=False)
 
 @conf
 def link_add_flags(conf):
 	"""
 	Add LINKFLAGS / LDFLAGS from os.environ to conf.env
 	"""
-	conf.add_os_flags('LINKFLAGS')
-	conf.add_os_flags('LDFLAGS')
+	conf.add_os_flags('LINKFLAGS', dup=False)
+	conf.add_os_flags('LDFLAGS', dup=False)
 
 @conf
 def cc_load_tools(conf):
@@ -978,15 +1005,10 @@ def get_cc_version(conf, cc, gcc=False, icc=False, clang=False):
 	cmd = cc + ['-dM', '-E', '-']
 	env = conf.env.env or None
 	try:
-		p = Utils.subprocess.Popen(cmd, stdin=Utils.subprocess.PIPE, stdout=Utils.subprocess.PIPE, stderr=Utils.subprocess.PIPE, env=env)
-		p.stdin.write('\n'.encode())
-		out = p.communicate()[0]
+		out, err = conf.cmd_and_log(cmd, output=0, input='\n'.encode(), env=env)
 	except Exception:
 		conf.fatal('Could not determine the compiler version %r' % cmd)
 
-	if not isinstance(out, str):
-		out = out.decode(sys.stdout.encoding or 'iso8859-1')
-
 	if gcc:
 		if out.find('__INTEL_COMPILER') >= 0:
 			conf.fatal('The intel compiler pretends to be gcc')
@@ -999,7 +1021,7 @@ def get_cc_version(conf, cc, gcc=False, icc=False, clang=False):
 	if clang and out.find('__clang__') < 0:
 		conf.fatal('Not clang/clang++')
 	if not clang and out.find('__clang__') >= 0:
-		conf.fatal('Could not find g++, if renamed try eg: CXX=g++48 waf configure')
+		conf.fatal('Could not find gcc/g++ (only Clang), if renamed try eg: CC=gcc48 CXX=g++48 waf configure')
 
 	k = {}
 	if icc or gcc or clang:
@@ -1014,9 +1036,6 @@ def get_cc_version(conf, cc, gcc=False, icc=False, clang=False):
 		def isD(var):
 			return var in k
 
-		def isT(var):
-			return var in k and k[var] != '0'
-
 		# Some documentation is available at http://predef.sourceforge.net
 		# The names given to DEST_OS must match what Utils.unversioned_sys_platform() returns.
 		if not conf.env.DEST_OS:
@@ -1053,17 +1072,11 @@ def get_cc_version(conf, cc, gcc=False, icc=False, clang=False):
 			ver = k['__INTEL_COMPILER']
 			conf.env['CC_VERSION'] = (ver[:-2], ver[-2], ver[-1])
 		else:
-			if isD('__clang__'):
-				try:
-					conf.env['CC_VERSION'] = (k['__clang_major__'], k['__clang_minor__'], k['__clang_patchlevel__'])
-				except KeyError:
-					# Some versions of OSX have a faux-gcc "clang" without clang version defines
-					conf.env['CC_VERSION'] = (k['__GNUC__'], k['__GNUC_MINOR__'], k['__GNUC_PATCHLEVEL__'])
+			if isD('__clang__') and isD('__clang_major__'):
+				conf.env['CC_VERSION'] = (k['__clang_major__'], k['__clang_minor__'], k['__clang_patchlevel__'])
 			else:
-				try:
-					conf.env['CC_VERSION'] = (k['__GNUC__'], k['__GNUC_MINOR__'], k['__GNUC_PATCHLEVEL__'])
-				except KeyError:
-					conf.env['CC_VERSION'] = (k['__GNUC__'], k['__GNUC_MINOR__'], 0)
+				# older clang versions and gcc
+				conf.env['CC_VERSION'] = (k['__GNUC__'], k['__GNUC_MINOR__'], k.get('__GNUC_PATCHLEVEL__', '0'))
 	return k
 
 @conf
@@ -1165,6 +1178,7 @@ def multicheck(self, *k, **kw):
 			self.keep = False
 			self.returned_tasks = []
 			self.task_sigs = {}
+			self.progress_bar = 0
 		def total(self):
 			return len(tasks)
 		def to_log(self, *k, **kw):
@@ -1195,10 +1209,17 @@ def multicheck(self, *k, **kw):
 	for x in tasks:
 		x.logger.memhandler.flush()
 
+	if p.error:
+		for x in p.error:
+			if getattr(x, 'err_msg', None):
+				self.to_log(x.err_msg)
+				self.end_msg('fail', color='RED')
+				raise Errors.WafError('There is an error in the library, read config.log for more information')
+
 	for x in tasks:
 		if x.hasrun != Task.SUCCESS:
 			self.end_msg(kw.get('errmsg', 'no'), color='YELLOW', **kw)
-			self.fatal(kw.get('fatalmsg', None) or 'One of the tests has failed, see the config.log for more information')
+			self.fatal(kw.get('fatalmsg', None) or 'One of the tests has failed, read config.log for more information')
 
 	self.end_msg('ok', **kw)
 
diff --git a/waflib/Tools/c_osx.py b/waflib/Tools/c_osx.py
index a2f62412..2b3c6474 100644
--- a/waflib/Tools/c_osx.py
+++ b/waflib/Tools/c_osx.py
@@ -24,7 +24,7 @@ app_info = '''
 	<key>NOTE</key>
 	<string>THIS IS A GENERATED FILE, DO NOT MODIFY</string>
 	<key>CFBundleExecutable</key>
-	<string>%s</string>
+	<string>{app_name}</string>
 </dict>
 </plist>
 '''
@@ -71,7 +71,7 @@ def create_task_macapp(self):
 	To compile an executable into a Mac application (a .app), set its *mac_app* attribute::
 
 		def build(bld):
-			bld.shlib(source='a.c', target='foo', mac_app = True)
+			bld.shlib(source='a.c', target='foo', mac_app=True)
 
 	To force *all* executables to be transformed into Mac applications::
 
@@ -91,7 +91,22 @@ def create_task_macapp(self):
 		inst_to = getattr(self, 'install_path', '/Applications') + '/%s/Contents/MacOS/' % name
 		self.bld.install_files(inst_to, n1, chmod=Utils.O755)
 
+		if getattr(self, 'mac_files', None):
+			# this only accepts files; they will be installed as seen from mac_files_root
+			mac_files_root = getattr(self, 'mac_files_root', None)
+			if isinstance(mac_files_root, str):
+				mac_files_root = self.path.find_node(mac_files_root)
+				if not mac_files_root:
+					self.bld.fatal('Invalid mac_files_root %r' % self.mac_files_root)
+			res_dir = n1.parent.parent.make_node('Resources')
+			inst_to = getattr(self, 'install_path', '/Applications') + '/%s/Resources' % name
+			for node in self.to_nodes(self.mac_files):
+				relpath = node.path_from(mac_files_root or node.parent)
+				tsk = self.create_task('macapp', node, res_dir.make_node(relpath))
+				self.bld.install_as(os.path.join(inst_to, relpath), node)
+
 		if getattr(self, 'mac_resources', None):
+			# TODO remove in waf 1.9
 			res_dir = n1.parent.parent.make_node('Resources')
 			inst_to = getattr(self, 'install_path', '/Applications') + '/%s/Resources' % name
 			for x in self.to_list(self.mac_resources):
@@ -127,6 +142,14 @@ def create_task_macplist(self):
 		dir = self.create_bundle_dirs(name, out)
 		n1 = dir.find_or_declare(['Contents', 'Info.plist'])
 		self.plisttask = plisttask = self.create_task('macplist', [], n1)
+		plisttask.context = {
+			'app_name': self.link_task.outputs[0].name,
+			'env': self.env
+		}
+
+		plist_ctx = getattr(self, 'plist_context', None)
+		if (plist_ctx):
+			plisttask.context.update(plist_ctx)
 
 		if getattr(self, 'mac_plist', False):
 			node = self.path.find_resource(self.mac_plist)
@@ -135,7 +158,7 @@ def create_task_macplist(self):
 			else:
 				plisttask.code = self.mac_plist
 		else:
-			plisttask.code = app_info % self.link_task.outputs[0].name
+			plisttask.code = app_info
 
 		inst_to = getattr(self, 'install_path', '/Applications') + '/%s/Contents/' % name
 		self.bld.install_files(inst_to, n1)
@@ -184,5 +207,6 @@ class macplist(Task.Task):
 			txt = self.code
 		else:
 			txt = self.inputs[0].read()
+		context = getattr(self, 'context', {})
+		txt = txt.format(**context)
 		self.outputs[0].write(txt)
-
diff --git a/waflib/Tools/ccroot.py b/waflib/Tools/ccroot.py
index 05484e30..363d18d1 100644
--- a/waflib/Tools/ccroot.py
+++ b/waflib/Tools/ccroot.py
@@ -489,10 +489,19 @@ def apply_vnum(self):
 		def build(bld):
 			bld.shlib(source='a.c', target='foo', vnum='14.15.16')
 
-	In this example, ``libfoo.so`` is installed as ``libfoo.so.1.2.3``, and the following symbolic links are created:
+	In this example on Linux platform, ``libfoo.so`` is installed as ``libfoo.so.14.15.16``, and the following symbolic links are created:
 
-	* ``libfoo.so   → libfoo.so.1.2.3``
-	* ``libfoo.so.1 → libfoo.so.1.2.3``
+	* ``libfoo.so    → libfoo.so.14.15.16``
+	* ``libfoo.so.14 → libfoo.so.14.15.16``
+
+	By default, the library will be assigned SONAME ``libfoo.so.14``, effectively declaring ABI compatibility between all minor and patch releases for the major version of the library.  When necessary, the compatibility can be explicitly defined using `cnum` parameter:
+
+		def build(bld):
+			bld.shlib(source='a.c', target='foo', vnum='14.15.16', cnum='14.15')
+
+	In this case, the assigned SONAME will be ``libfoo.so.14.15`` with ABI compatibility only between path releases for a specific major and minor version of the library.
+
+	On OS X platform, install-name parameter will follow the above logic for SONAME with exception that it also specifies an absolute path (based on install_path) of the library.
 	"""
 	if not getattr(self, 'vnum', '') or os.name != 'posix' or self.env.DEST_BINFMT not in ('elf', 'mac-o'):
 		return
@@ -503,13 +512,18 @@ def apply_vnum(self):
 	nums = self.vnum.split('.')
 	node = link.outputs[0]
 
+	cnum = getattr(self, 'cnum', str(nums[0]))
+	cnums = cnum.split('.')
+	if len(cnums)>len(nums) or nums[0:len(cnums)] != cnums:
+		raise Errors.WafError('invalid compatibility version %s' % cnum)
+
 	libname = node.name
 	if libname.endswith('.dylib'):
 		name3 = libname.replace('.dylib', '.%s.dylib' % self.vnum)
-		name2 = libname.replace('.dylib', '.%s.dylib' % nums[0])
+		name2 = libname.replace('.dylib', '.%s.dylib' % cnum)
 	else:
 		name3 = libname + '.' + self.vnum
-		name2 = libname + '.' + nums[0]
+		name2 = libname + '.' + cnum
 
 	# add the so name for the ld linker - to disable, just unset env.SONAME_ST
 	if self.env.SONAME_ST:
@@ -548,8 +562,10 @@ def apply_vnum(self):
 			inst_to = self.link_task.__class__.inst_to
 		if inst_to:
 			p = Utils.subst_vars(inst_to, self.env)
-			path = os.path.join(p, self.link_task.outputs[0].name)
+			path = os.path.join(p, name2)
 			self.env.append_value('LINKFLAGS', ['-install_name', path])
+			self.env.append_value('LINKFLAGS', '-Wl,-compatibility_version,%s' % cnum)
+			self.env.append_value('LINKFLAGS', '-Wl,-current_version,%s' % self.vnum)
 
 class vnum(Task.Task):
 	"""
diff --git a/waflib/Tools/clang.py b/waflib/Tools/clang.py
index 999c604c..0740e00b 100644
--- a/waflib/Tools/clang.py
+++ b/waflib/Tools/clang.py
@@ -21,6 +21,7 @@ def find_clang(conf):
 
 def configure(conf):
 	conf.find_clang()
+	conf.find_program(['llvm-ar', 'ar'], var='AR')
 	conf.find_ar()
 	conf.gcc_common_flags()
 	conf.gcc_modifier_platform()
diff --git a/waflib/Tools/clangxx.py b/waflib/Tools/clangxx.py
index c8d34a71..b52fc352 100644
--- a/waflib/Tools/clangxx.py
+++ b/waflib/Tools/clangxx.py
@@ -21,6 +21,7 @@ def find_clangxx(conf):
 
 def configure(conf):
 	conf.find_clangxx()
+	conf.find_program(['llvm-ar', 'ar'], var='AR')
 	conf.find_ar()
 	conf.gxx_common_flags()
 	conf.gxx_modifier_platform()
diff --git a/waflib/Tools/errcheck.py b/waflib/Tools/errcheck.py
index 9ac0cafe..14ce28fb 100644
--- a/waflib/Tools/errcheck.py
+++ b/waflib/Tools/errcheck.py
@@ -64,7 +64,7 @@ def check_same_targets(self):
 	if not dupe:
 		for (k, v) in uids.items():
 			if len(v) > 1:
-				Logs.error('* Several tasks use the same identifier. Please check the information on\n   http://docs.waf.googlecode.com/git/apidocs_16/Task.html#waflib.Task.Task.uid')
+				Logs.error('* Several tasks use the same identifier. Please check the information on\n   https://waf.io/apidocs/Task.html?highlight=uid#waflib.Task.Task.uid')
 				for tsk in v:
 					Logs.error('  - object %r (%r) defined in %r' % (tsk.__class__.__name__, tsk, tsk.generator))
 
diff --git a/waflib/Tools/gcc.py b/waflib/Tools/gcc.py
index 8cb954f8..741a2e3f 100644
--- a/waflib/Tools/gcc.py
+++ b/waflib/Tools/gcc.py
@@ -97,7 +97,7 @@ def gcc_modifier_darwin(conf):
 	"""Configuration flags for executing gcc on MacOS"""
 	v = conf.env
 	v['CFLAGS_cshlib']       = ['-fPIC']
-	v['LINKFLAGS_cshlib']    = ['-dynamiclib', '-Wl,-compatibility_version,1', '-Wl,-current_version,1']
+	v['LINKFLAGS_cshlib']    = ['-dynamiclib']
 	v['cshlib_PATTERN']      = 'lib%s.dylib'
 	v['FRAMEWORKPATH_ST']    = '-F%s'
 	v['FRAMEWORK_ST']        = ['-framework']
diff --git a/waflib/Tools/gxx.py b/waflib/Tools/gxx.py
index 55bf2a70..4c89273b 100644
--- a/waflib/Tools/gxx.py
+++ b/waflib/Tools/gxx.py
@@ -97,7 +97,7 @@ def gxx_modifier_darwin(conf):
 	"""Configuration flags for executing g++ on MacOS"""
 	v = conf.env
 	v['CXXFLAGS_cxxshlib']   = ['-fPIC']
-	v['LINKFLAGS_cxxshlib']  = ['-dynamiclib', '-Wl,-compatibility_version,1', '-Wl,-current_version,1']
+	v['LINKFLAGS_cxxshlib']  = ['-dynamiclib']
 	v['cxxshlib_PATTERN']    = 'lib%s.dylib'
 	v['FRAMEWORKPATH_ST']    = '-F%s'
 	v['FRAMEWORK_ST']        = ['-framework']
diff --git a/waflib/Tools/msvc.py b/waflib/Tools/msvc.py
index 97323247..c220f3f9 100644
--- a/waflib/Tools/msvc.py
+++ b/waflib/Tools/msvc.py
@@ -30,6 +30,10 @@ or::
 
 Platforms and targets will be tested in the order they appear;
 the first good configuration will be used.
+
+To skip testing all the configurations that are not used, use the ``--msvc_lazy_autodetect`` option
+or set ``conf.env['MSVC_LAZY_AUTODETECT']=True``.
+
 Supported platforms: ia64, x64, x86, x86_amd64, x86_ia64, x86_arm, amd64_x86, amd64_arm
 
 Compilers supported:
@@ -90,8 +94,18 @@ all_icl_platforms = [ ('intel64', 'amd64'), ('em64t', 'amd64'), ('ia32', 'x86'),
 def options(opt):
 	opt.add_option('--msvc_version', type='string', help = 'msvc version, eg: "msvc 10.0,msvc 9.0"', default='')
 	opt.add_option('--msvc_targets', type='string', help = 'msvc targets, eg: "x64,arm"', default='')
+	opt.add_option('--msvc_lazy_autodetect', action='store_true', help = 'lazily check msvc target environments')
 
 def setup_msvc(conf, versions, arch = False):
+	"""
+	Checks installed compilers and targets and returns the first combination from the user's
+	options, env, or the global supported lists that checks.
+
+	:param versions: A list of tuples of all installed compilers and available targets.
+	:param arch: Whether to return the target architecture.
+	:return: the compiler, revision, path, include dirs, library paths, and (optionally) target architecture
+	:rtype: tuple of strings
+	"""
 	platforms = getattr(Options.options, 'msvc_targets', '').split(',')
 	if platforms == ['']:
 		platforms=Utils.to_list(conf.env['MSVC_TARGETS']) or [i for i,j in all_msvc_platforms+all_icl_platforms+all_wince_platforms]
@@ -102,15 +116,20 @@ def setup_msvc(conf, versions, arch = False):
 
 	for version in desired_versions:
 		try:
-			targets = dict(versiondict [version])
+			targets = dict(versiondict[version])
 			for target in platforms:
 				try:
-					arch,(p1,p2,p3) = targets[target]
-					compiler,revision = version.rsplit(' ', 1)
-					if arch:
-						return compiler,revision,p1,p2,p3,arch
+					try:
+						realtarget,(p1,p2,p3) = targets[target]
+					except conf.errors.ConfigurationError:
+						# lazytup target evaluation errors
+						del(targets[target])
 					else:
-						return compiler,revision,p1,p2,p3
+						compiler,revision = version.rsplit(' ', 1)
+						if arch:
+							return compiler,revision,p1,p2,p3,realtarget
+						else:
+							return compiler,revision,p1,p2,p3
 				except KeyError: continue
 		except KeyError: continue
 	conf.fatal('msvc: Impossible to find a valid architecture for building (in setup_msvc)')
@@ -118,13 +137,14 @@ def setup_msvc(conf, versions, arch = False):
 @conf
 def get_msvc_version(conf, compiler, version, target, vcvars):
 	"""
-	Create a bat file to obtain the location of the libraries
-
-	:param compiler: ?
-	:param version: ?
-	:target: ?
-	:vcvars: ?
-	:return: the location of msvc, the location of include dirs, and the library paths
+	Checks that an installed compiler actually runs and uses vcvars to obtain the
+	environment needed by the compiler.
+
+	:param compiler: compiler type, for looking up the executable name
+	:param version: compiler version, for debugging only
+	:param target: target architecture
+	:param vcvars: batch file to run to check the environment
+	:return: the location of the compiler executable, the location of include dirs, and the library paths
 	:rtype: tuple of strings
 	"""
 	debug('msvc: get_msvc_version: %r %r %r', compiler, version, target)
@@ -219,7 +239,7 @@ def gather_wsdk_versions(conf, versions):
 			targets = []
 			for target,arch in all_msvc_platforms:
 				try:
-					targets.append((target, (arch, conf.get_msvc_version('wsdk', version, '/'+target, os.path.join(path, 'bin', 'SetEnv.cmd')))))
+					targets.append((target, (arch, get_compiler_env(conf, 'wsdk', version, '/'+target, os.path.join(path, 'bin', 'SetEnv.cmd')))))
 				except conf.errors.ConfigurationError:
 					pass
 			versions.append(('wsdk ' + version[1:], targets))
@@ -262,12 +282,12 @@ def gather_wince_supported_platforms():
 		path,device = os.path.split(path)
 		if not device:
 			path,device = os.path.split(path)
+		platforms = []
 		for arch,compiler in all_wince_platforms:
-			platforms = []
 			if os.path.isdir(os.path.join(path, device, 'Lib', arch)):
 				platforms.append((arch, compiler, os.path.join(path, device, 'Include', arch), os.path.join(path, device, 'Lib', arch)))
-			if platforms:
-				supported_wince_platforms.append((device, platforms))
+		if platforms:
+			supported_wince_platforms.append((device, platforms))
 	return supported_wince_platforms
 
 def gather_msvc_detected_versions():
@@ -304,6 +324,65 @@ def gather_msvc_detected_versions():
 	detected_versions.sort(key = fun)
 	return detected_versions
 
+def get_compiler_env(conf, compiler, version, bat_target, bat, select=None):
+	"""
+	Gets the compiler environment variables as a tuple. Evaluation is eager by default.
+	If set to lazy with ``--msvc_lazy_autodetect`` or ``env.MSVC_LAZY_AUTODETECT``
+        the environment is evaluated when the tuple is destructured or iterated. This means
+        destructuring can throw :py:class:`conf.errors.ConfigurationError`.
+
+	:param conf: configuration context to use to eventually get the version environment
+	:param compiler: compiler name
+	:param version: compiler version number
+	:param bat: path to the batch file to run
+	:param select: optional function to take the realized environment variables tup and map it (e.g. to combine other constant paths)
+	"""
+	lazy = getattr(Options.options, 'msvc_lazy_autodetect', False) or conf.env['MSVC_LAZY_AUTODETECT']
+
+	def msvc_thunk():
+		vs = conf.get_msvc_version(compiler, version, bat_target, bat)
+		if select:
+			return select(vs)
+		else:
+			return vs
+	return lazytup(msvc_thunk, lazy, ([], [], []))
+
+class lazytup(object):
+	"""
+	A tuple that evaluates its elements from a function when iterated or destructured.
+	
+	:param fn: thunk to evaluate the tuple on demand
+	:param lazy: whether to delay evaluation or evaluate in the constructor
+	:param default: optional default for :py:func:`repr` if it should not evaluate
+	"""
+        def __init__(self, fn, lazy=True, default=None):
+		self.fn = fn
+		self.default = default
+		if not lazy:
+			self.evaluate()
+        def __len__(self):
+		self.evaluate()
+                return len(self.value)
+        def __iter__(self):
+		self.evaluate()
+                for i, v in enumerate(self.value):
+                        yield v
+        def __getitem__(self, i):
+		self.evaluate()
+                return self.value[i]
+	def __repr__(self):
+		if hasattr(self, 'value'):
+			return repr(self.value)
+		elif self.default:
+			return repr(self.default)
+		else:
+			self.evaluate()
+			return repr(self.value)
+	def evaluate(self):
+		if hasattr(self, 'value'):
+			return
+		self.value = self.fn()
+
 @conf
 def gather_msvc_targets(conf, versions, version, vc_path):
 	#Looking for normal MSVC compilers!
@@ -311,17 +390,17 @@ def gather_msvc_targets(conf, versions, version, vc_path):
 	if os.path.isfile(os.path.join(vc_path, 'vcvarsall.bat')):
 		for target,realtarget in all_msvc_platforms[::-1]:
 			try:
-				targets.append((target, (realtarget, conf.get_msvc_version('msvc', version, target, os.path.join(vc_path, 'vcvarsall.bat')))))
+				targets.append((target, (realtarget, get_compiler_env(conf, 'msvc', version, target, os.path.join(vc_path, 'vcvarsall.bat')))))
 			except conf.errors.ConfigurationError:
 				pass
 	elif os.path.isfile(os.path.join(vc_path, 'Common7', 'Tools', 'vsvars32.bat')):
 		try:
-			targets.append(('x86', ('x86', conf.get_msvc_version('msvc', version, 'x86', os.path.join(vc_path, 'Common7', 'Tools', 'vsvars32.bat')))))
+			targets.append(('x86', ('x86', get_compiler_env(conf, 'msvc', version, 'x86', os.path.join(vc_path, 'Common7', 'Tools', 'vsvars32.bat')))))
 		except conf.errors.ConfigurationError:
 			pass
 	elif os.path.isfile(os.path.join(vc_path, 'Bin', 'vcvars32.bat')):
 		try:
-			targets.append(('x86', ('x86', conf.get_msvc_version('msvc', version, '', os.path.join(vc_path, 'Bin', 'vcvars32.bat')))))
+			targets.append(('x86', ('x86', get_compiler_env(conf, 'msvc', version, '', os.path.join(vc_path, 'Bin', 'vcvars32.bat')))))
 		except conf.errors.ConfigurationError:
 			pass
 	if targets:
@@ -336,15 +415,18 @@ def gather_wince_targets(conf, versions, version, vc_path, vsvars, supported_pla
 			winCEpath = os.path.join(vc_path, 'ce')
 			if not os.path.isdir(winCEpath):
 				continue
-			try:
-				common_bindirs,_1,_2 = conf.get_msvc_version('msvc', version, 'x86', vsvars)
-			except conf.errors.ConfigurationError:
-				continue
+
 			if os.path.isdir(os.path.join(winCEpath, 'lib', platform)):
-				bindirs = [os.path.join(winCEpath, 'bin', compiler), os.path.join(winCEpath, 'bin', 'x86_'+compiler)] + common_bindirs
+				bindirs = [os.path.join(winCEpath, 'bin', compiler), os.path.join(winCEpath, 'bin', 'x86_'+compiler)]
 				incdirs = [os.path.join(winCEpath, 'include'), os.path.join(winCEpath, 'atlmfc', 'include'), include]
 				libdirs = [os.path.join(winCEpath, 'lib', platform), os.path.join(winCEpath, 'atlmfc', 'lib', platform), lib]
-				cetargets.append((platform, (platform, (bindirs,incdirs,libdirs))))
+				def combine_common(compiler_env):
+					(common_bindirs,_1,_2) = compiler_env
+					return (bindirs + common_bindirs, incdirs, libdirs)
+				try:
+					cetargets.append((platform, (platform, get_compiler_env(conf, 'msvc', version, 'x86', vsvars, combine_common))))
+				except conf.errors.ConfigurationError:
+					continue
 		if cetargets:
 			versions.append((device + ' ' + version, cetargets))
 
@@ -354,8 +436,8 @@ def gather_winphone_targets(conf, versions, version, vc_path, vsvars):
 	targets = []
 	for target,realtarget in all_msvc_platforms[::-1]:
 		try:
-			targets.append((target, (realtarget, conf.get_msvc_version('winphone', version, target, vsvars))))
-		except conf.errors.ConfigurationError as e:
+			targets.append((target, (realtarget, get_compiler_env(conf, 'winphone', version, target, vsvars))))
+		except conf.errors.ConfigurationError:
 			pass
 	if targets:
 		versions.append(('winphone '+ version, targets))
@@ -382,9 +464,14 @@ def gather_msvc_versions(conf, versions):
 		if wince_supported_platforms and os.path.isfile(vsvars):
 			conf.gather_wince_targets(versions, version, vc_path, vsvars, wince_supported_platforms)
 
+	# WP80 works with 11.0Exp and 11.0, both of which resolve to the same vc_path.
+	# Stop after one is found.
+	for version,vc_path in vc_paths:
+		vs_path = os.path.dirname(vc_path)
 		vsvars = os.path.join(vs_path, 'VC', 'WPSDK', 'WP80', 'vcvarsphoneall.bat')
 		if os.path.isfile(vsvars):
 			conf.gather_winphone_targets(versions, '8.0', vc_path, vsvars)
+			break
 
 	for version,vc_path in vc_paths:
 		vs_path = os.path.dirname(vc_path)
@@ -426,7 +513,7 @@ def gather_icl_versions(conf, versions):
 				batch_file=os.path.join(path,'bin','iclvars.bat')
 				if os.path.isfile(batch_file):
 					try:
-						targets.append((target,(arch,conf.get_msvc_version('intel',version,target,batch_file))))
+						targets.append((target,(arch,get_compiler_env(conf,'intel',version,target,batch_file))))
 					except conf.errors.ConfigurationError:
 						pass
 			except WindowsError:
@@ -438,7 +525,7 @@ def gather_icl_versions(conf, versions):
 				batch_file=os.path.join(path,'bin','iclvars.bat')
 				if os.path.isfile(batch_file):
 					try:
-						targets.append((target, (arch, conf.get_msvc_version('intel', version, target, batch_file))))
+						targets.append((target, (arch, get_compiler_env(conf, 'intel', version, target, batch_file))))
 					except conf.errors.ConfigurationError:
 						pass
 			except WindowsError:
@@ -490,8 +577,8 @@ def gather_intel_composer_versions(conf, versions):
 				batch_file=os.path.join(path,'bin','iclvars.bat')
 				if os.path.isfile(batch_file):
 					try:
-						targets.append((target,(arch,conf.get_msvc_version('intel',version,target,batch_file))))
-					except conf.errors.ConfigurationError as e:
+						targets.append((target,(arch,get_compiler_env(conf,'intel',version,target,batch_file))))
+					except conf.errors.ConfigurationError:
 						pass
 				# The intel compilervar_arch.bat is broken when used with Visual Studio Express 2012
 				# http://software.intel.com/en-us/forums/topic/328487
@@ -516,19 +603,36 @@ def gather_intel_composer_versions(conf, versions):
 		versions.append(('intel ' + major, targets))
 
 @conf
-def get_msvc_versions(conf):
+def get_msvc_versions(conf, eval_and_save=True):
 	"""
 	:return: list of compilers installed
 	:rtype: list of string
 	"""
-	if not conf.env['MSVC_INSTALLED_VERSIONS']:
-		lst = []
-		conf.gather_icl_versions(lst)
-		conf.gather_intel_composer_versions(lst)
-		conf.gather_wsdk_versions(lst)
-		conf.gather_msvc_versions(lst)
+	if conf.env['MSVC_INSTALLED_VERSIONS']:
+		return conf.env['MSVC_INSTALLED_VERSIONS']
+
+	# Gather all the compiler versions and targets. This phase can be lazy
+	# per lazy detection settings.
+	lst = []
+	conf.gather_icl_versions(lst)
+	conf.gather_intel_composer_versions(lst)
+	conf.gather_wsdk_versions(lst)
+	conf.gather_msvc_versions(lst)
+
+	# Override lazy detection by evaluating after the fact.
+	if eval_and_save:
+		def checked_target(t):
+			target,(arch,paths) = t
+			try:
+				paths.evaluate()
+			except conf.errors.ConfigurationError:
+				return None
+			else:
+				return t
+		lst = [(version, list(filter(checked_target, targets))) for version, targets in lst]
 		conf.env['MSVC_INSTALLED_VERSIONS'] = lst
-	return conf.env['MSVC_INSTALLED_VERSIONS']
+
+	return lst
 
 @conf
 def print_all_msvc_detected(conf):
@@ -542,7 +646,9 @@ def print_all_msvc_detected(conf):
 
 @conf
 def detect_msvc(conf, arch = False):
-	versions = get_msvc_versions(conf)
+	# Save installed versions only if lazy detection is disabled.
+	lazy_detect = getattr(Options.options, 'msvc_lazy_autodetect', False) or conf.env['MSVC_LAZY_AUTODETECT']
+	versions = get_msvc_versions(conf, not lazy_detect)
 	return setup_msvc(conf, versions, arch)
 
 @conf
diff --git a/waflib/Tools/suncc.py b/waflib/Tools/suncc.py
index e705c328..4909854e 100644
--- a/waflib/Tools/suncc.py
+++ b/waflib/Tools/suncc.py
@@ -3,7 +3,6 @@
 # Thomas Nagy, 2006-2010 (ita)
 # Ralf Habacker, 2006 (rh)
 
-from waflib import Utils
 from waflib.Tools import ccroot, ar
 from waflib.Configure import conf
 
@@ -53,7 +52,7 @@ def scc_common_flags(conf):
 	v['cprogram_PATTERN']    = '%s'
 
 	# shared library
-	v['CFLAGS_cshlib']       = ['-Kpic', '-DPIC']
+	v['CFLAGS_cshlib']       = ['-xcode=pic32', '-DPIC']
 	v['LINKFLAGS_cshlib']    = ['-G']
 	v['cshlib_PATTERN']      = 'lib%s.so'
 
@@ -68,4 +67,3 @@ def configure(conf):
 	conf.cc_load_tools()
 	conf.cc_add_flags()
 	conf.link_add_flags()
-
diff --git a/waflib/Tools/suncxx.py b/waflib/Tools/suncxx.py
index 01b3f8d2..5a04b483 100644
--- a/waflib/Tools/suncxx.py
+++ b/waflib/Tools/suncxx.py
@@ -3,7 +3,6 @@
 # Thomas Nagy, 2006-2010 (ita)
 # Ralf Habacker, 2006 (rh)
 
-from waflib import Utils
 from waflib.Tools import ccroot, ar
 from waflib.Configure import conf
 
@@ -51,7 +50,7 @@ def sxx_common_flags(conf):
 	v['cxxprogram_PATTERN']  = '%s'
 
 	# shared library
-	v['CXXFLAGS_cxxshlib']   = ['-Kpic', '-DPIC']
+	v['CXXFLAGS_cxxshlib']   = ['-xcode=pic32', '-DPIC']
 	v['LINKFLAGS_cxxshlib']  = ['-G']
 	v['cxxshlib_PATTERN']    = 'lib%s.so'
 
diff --git a/waflib/ansiterm.py b/waflib/ansiterm.py
index e7a4ce75..64fa1407 100644
--- a/waflib/ansiterm.py
+++ b/waflib/ansiterm.py
@@ -284,7 +284,7 @@ else:
 				wlock.release()
 
 		def writeconsole(self, txt):
-			chars_written = c_int()
+			chars_written = c_ulong()
 			writeconsole = windll.kernel32.WriteConsoleA
 			if isinstance(txt, _type):
 				writeconsole = windll.kernel32.WriteConsoleW
diff --git a/waflib/extras/lru_cache.py b/waflib/extras/lru_cache.py
deleted file mode 100644
index 2bc96442..00000000
--- a/waflib/extras/lru_cache.py
+++ /dev/null
@@ -1,98 +0,0 @@
-#! /usr/bin/env python
-# encoding: utf-8
-# Thomas Nagy 2011
-
-import os, shutil, re
-from waflib import Options, Build, Logs
-
-"""
-Apply a least recently used policy to the Waf cache.
-
-For performance reasons, it is called after the build is complete.
-
-We assume that the the folders are written atomically
-
-Do export WAFCACHE=/tmp/foo_xyz where xyz represents the cache size in bytes
-If missing, the default cache size will be set to 10GB
-"""
-
-re_num = re.compile('[a-zA-Z_-]+(\d+)')
-
-CACHESIZE = 10*1024*1024*1024 # in bytes
-CLEANRATIO = 0.8
-DIRSIZE = 4096
-
-def compile(self):
-	if Options.cache_global and not Options.options.nocache:
-		try:
-			os.makedirs(Options.cache_global)
-		except:
-			pass
-
-	try:
-		self.raw_compile()
-	finally:
-		if Options.cache_global and not Options.options.nocache:
-			self.sweep()
-
-def sweep(self):
-	global CACHESIZE
-	CACHEDIR = Options.cache_global
-
-	# get the cache max size from the WAFCACHE filename
-	re_num = re.compile('[a-zA-Z_]+(\d+)')
-	val = re_num.sub('\\1', os.path.basename(Options.cache_global))
-	try:
-		CACHESIZE = int(val)
-	except:
-		pass
-
-	# map folder names to timestamps
-	flist = {}
-	for x in os.listdir(CACHEDIR):
-		j = os.path.join(CACHEDIR, x)
-		if os.path.isdir(j) and len(x) == 64: # dir names are md5 hexdigests
-			flist[x] = [os.stat(j).st_mtime, 0]
-
-	for (x, v) in flist.items():
-		cnt = DIRSIZE # each entry takes 4kB
-		d = os.path.join(CACHEDIR, x)
-		for k in os.listdir(d):
-			cnt += os.stat(os.path.join(d, k)).st_size
-		flist[x][1] = cnt
-
-	total = sum([x[1] for x in flist.values()])
-	Logs.debug('lru: Cache size is %r' % total)
-
-	if total >= CACHESIZE:
-		Logs.debug('lru: Trimming the cache since %r > %r' % (total, CACHESIZE))
-
-		# make a list to sort the folders by timestamp
-		lst = [(p, v[0], v[1]) for (p, v) in flist.items()]
-		lst.sort(key=lambda x: x[1]) # sort by timestamp
-		lst.reverse()
-
-		while total >= CACHESIZE * CLEANRATIO:
-			(k, t, s) = lst.pop()
-			p = os.path.join(CACHEDIR, k)
-			v = p + '.del'
-			try:
-				os.rename(p, v)
-			except:
-				# someone already did it
-				pass
-			else:
-				try:
-					shutil.rmtree(v)
-				except:
-					# this should not happen, but who knows?
-					Logs.warn('If you ever see this message, report it (%r)' % v)
-			total -= s
-			del flist[k]
-
-	Logs.debug('lru: Total at the end %r' % total)
-
-Build.BuildContext.raw_compile = Build.BuildContext.compile
-Build.BuildContext.compile = compile
-Build.BuildContext.sweep = sweep
-