Use the 'with' syntax whenever possible

waflib/Scripting.py

@@ -4,6 +4,8 @@
 
 "Module called for configuring, compiling and installing targets"
 
+from __future__ import with_statement
+
 import os, shlex, shutil, traceback, errno, sys, stat
 from waflib import Utils, Configure, Logs, Options, ConfigSet, Context, Errors, Build, Node
 
@@ -406,11 +408,8 @@ class Dist(Context.Context):
 		tinfo.gname = 'root'
 
 		if os.path.isfile(p):
-			fu = open(p, 'rb')
-			try:
-				tar.addfile(tinfo, fileobj=fu)
-			finally:
-				fu.close()
+			with open(p, 'rb') as f:
+				tar.addfile(tinfo, fileobj=f)
 		else:
 			tar.addfile(tinfo)
 
@@ -532,12 +531,9 @@ class DistCheck(Dist):
 		"""
 		import tempfile, tarfile
 
-		try:
-			t = tarfile.open(self.get_arch_name())
+		with tarfile.open(self.get_arch_name()) as t:
 			for x in t:
 				t.extract(x)
-		finally:
-			t.close()
 
 		instdir = tempfile.mkdtemp('.inst', self.get_base_name())
 		cmd = self.make_distcheck_cmd(instdir)

waflib/Tools/intltool.py

@@ -27,6 +27,8 @@ Usage::
 Usage of the :py:mod:`waflib.Tools.gnu_dirs` is recommended, but not obligatory.
 """
 
+from __future__ import with_statement
+
 import os, re
 from waflib import Context, Task, Utils, Logs
 import waflib.Tools.ccroot
@@ -157,13 +159,12 @@ def apply_intltool_po(self):
 	linguas = self.path.find_node(os.path.join(podir, 'LINGUAS'))
 	if linguas:
 		# scan LINGUAS file for locales to process
-		file = open(linguas.abspath())
-		langs = []
-		for line in file.readlines():
-			# ignore lines containing comments
-			if not line.startswith('#'):
-				langs += line.split()
-		file.close()
+		with open(linguas.abspath()) as f:
+			langs = []
+			for line in f.readlines():
+				# ignore lines containing comments
+				if not line.startswith('#'):
+					langs += line.split()
 		re_linguas = re.compile('[-a-zA-Z_@.]+')
 		for lang in langs:
 			# Make sure that we only process lines which contain locales

waflib/Tools/qt5.py

@@ -61,6 +61,8 @@ The detection uses pkg-config on Linux by default. To force static library detec
 QT5_XCOMPILE=1 QT5_FORCE_STATIC=1 waf configure
 """
 
+from __future__ import with_statement
+
 try:
 	from xml.sax import make_parser
 	from xml.sax.handler import ContentHandler
@@ -366,11 +368,8 @@ class rcc(Task.Task):
 		parser = make_parser()
 		curHandler = XMLHandler()
 		parser.setContentHandler(curHandler)
-		fi = open(self.inputs[0].abspath(), 'r')
-		try:
-			parser.parse(fi)
-		finally:
-			fi.close()
+		with open(self.inputs[0].abspath(), 'r') as f:
+			parser.parse(f)
 
 		nodes = []
 		names = []

waflib/Utils.py

@@ -9,6 +9,8 @@ The portability fixes try to provide a consistent behavior of the Waf API
 through Python versions 2.5 to 3.X and across different platforms (win32, linux, etc)
 """
 
+from __future__ import with_statement
+
 import atexit, os, sys, errno, inspect, re, datetime, platform, base64, signal, functools, time
 
 try:
@@ -209,21 +211,15 @@ def readf(fname, m='r', encoding='latin-1'):
 
 	if sys.hexversion > 0x3000000 and not 'b' in m:
 		m += 'b'
-		f = open(fname, m)
-		try:
+		with open(fname, m) as f:
 			txt = f.read()
-		finally:
-			f.close()
 		if encoding:
 			txt = txt.decode(encoding)
 		else:
 			txt = txt.decode()
 	else:
-		f = open(fname, m)
-		try:
+		with open(fname, m) as f:
 			txt = f.read()
-		finally:
-			f.close()
 	return txt
 
 def writef(fname, data, m='w', encoding='latin-1'):
@@ -248,11 +244,8 @@ def writef(fname, data, m='w', encoding='latin-1'):
 	if sys.hexversion > 0x3000000 and not 'b' in m:
 		data = data.encode(encoding)
 		m += 'b'
-	f = open(fname, m)
-	try:
+	with open(fname, m) as f:
 		f.write(data)
-	finally:
-		f.close()
 
 def h_file(fname):
 	"""
@@ -264,14 +257,11 @@ def h_file(fname):
 	:return: hash of the file contents
 	:rtype: string or bytes
 	"""
-	f = open(fname, 'rb')
 	m = md5()
-	try:
+	with open(fname, 'rb') as f:
 		while fname:
 			fname = f.read(200000)
 			m.update(fname)
-	finally:
-		f.close()
 	return m.digest()
 
 def readf_win32(f, m='r', encoding='latin-1'):
@@ -287,21 +277,15 @@ def readf_win32(f, m='r', encoding='latin-1'):
 
 	if sys.hexversion > 0x3000000 and not 'b' in m:
 		m += 'b'
-		f = os.fdopen(fd, m)
-		try:
+		with os.fdopen(fd, m) as f:
 			txt = f.read()
-		finally:
-			f.close()
 		if encoding:
 			txt = txt.decode(encoding)
 		else:
 			txt = txt.decode()
 	else:
-		f = os.fdopen(fd, m)
-		try:
+		with os.fdopen(fd, m) as f:
 			txt = f.read()
-		finally:
-			f.close()
 	return txt
 
 def writef_win32(f, data, m='w', encoding='latin-1'):
@@ -317,25 +301,19 @@ def writef_win32(f, data, m='w', encoding='latin-1'):
 		fd = os.open(f, flags)
 	except OSError:
 		raise OSError('Cannot write to %r' % f)
-	f = os.fdopen(fd, m)
-	try:
+	with os.fdopen(fd, m) as f:
 		f.write(data)
-	finally:
-		f.close()
 
 def h_file_win32(fname):
 	try:
 		fd = os.open(fname, os.O_BINARY | os.O_RDONLY | os.O_NOINHERIT)
 	except OSError:
 		raise OSError('Cannot read from %r' % fname)
-	f = os.fdopen(fd, 'rb')
 	m = md5()
-	try:
+	with os.fdopen(fd, 'rb') as f:
 		while fname:
 			fname = f.read(200000)
 			m.update(fname)
-	finally:
-		f.close()
 	return m.digest()
 
 # always save these

waflib/fixpy2.py

@@ -2,6 +2,8 @@
 # encoding: utf-8
 # Thomas Nagy, 2010-2017 (ita)
 
+from __future__ import with_statement
+
 import os
 
 all_modifs = {}
@@ -26,19 +28,13 @@ def modif(dir, name, fun):
 		return
 
 	filename = os.path.join(dir, name)
-	f = open(filename, 'r')
-	try:
+	with open(filename, 'r') as f:
 		txt = f.read()
-	finally:
-		f.close()
 
 	txt = fun(txt)
 
-	f = open(filename, 'w')
-	try:
+	with open(filename, 'w') as f:
 		f.write(txt)
-	finally:
-		f.close()
 
 def subst(*k):
 	"""register a substitution function"""

wscript

@@ -9,6 +9,8 @@ To add a tool that does not exist in the folder compat15, pass an absolute path:
 ./waf-light  --tools=compat15,/comp/waf/aba.py --prelude=$'\tfrom waflib.extras import aba\n\taba.foo()'
 """
 
+from __future__ import with_statement
+
 VERSION="2.0.0"
 APPNAME='waf'
 REVISION=''
@@ -28,21 +30,15 @@ from waflib import Configure
 Configure.autoconfig = 1
 
 def sub_file(fname, lst):
-	f = open(fname, 'rU')
-	try:
+	with open(fname, 'rU') as f:
 		txt = f.read()
-	finally:
-		f.close()
 
 	for (key, val) in lst:
 		re_pat = re.compile(key, re.M)
 		txt = re_pat.sub(val, txt)
 
-	f = open(fname, 'w')
-	try:
+	with open(fname, 'w') as f:
 		f.write(txt)
-	finally:
-		f.close()
 
 def to_bytes(x):
 	if sys.hexversion>0x300000f:
@@ -189,25 +185,16 @@ def sfilter(path):
 	if path.endswith('.py') :
 		if Options.options.strip_comments:
 			if sys.version_info[0] >= 3:
-				f = open(path, 'rb')
-				try:
+				with open(path, 'rb') as f:
 					tk = tokenize.tokenize(f.readline)
 					next(tk) # the first one is always tokenize.ENCODING for Python 3, ignore it
 					cnt = process_tokens(tk)
-				finally:
-					f.close()
 			else:
-				f = open(path, 'r')
-				try:
+				with open(path, 'r') as f:
 					cnt = process_tokens(tokenize.generate_tokens(f.readline))
-				finally:
-					f.close()
 		else:
-			f = open(path, 'r')
-			try:
+			with open(path, 'r') as f:
 				cnt = f.read()
-			finally:
-				f.close()
 		# WARNING: since python >= 2.5 is required, decorators are not processed anymore
 		# uncomment the following to enable decorator replacement:
 		#cnt = process_decorators(cnt)
@@ -216,11 +203,8 @@ def sfilter(path):
 		cnt = '#! /usr/bin/env python\n# encoding: utf-8\n# WARNING! Do not edit! https://waf.io/book/index.html#_obtaining_the_waf_file\n\n' + cnt
 
 	else:
-		f = open(path, 'r')
-		try:
+		with open(path, 'r') as f:
 			cnt = f.read()
-		finally:
-			f.close()
 
 	if sys.hexversion > 0x030000f0:
 		return (io.BytesIO(cnt.encode('utf-8')), len(cnt.encode('utf-8')), cnt)
@@ -331,11 +315,8 @@ def create_waf(self, *k, **kw):
 	tar.close()
 	z.close()
 
-	f = open('waf-light', 'rU')
-	try:
+	with open('waf-light', 'rU') as f:
 		code1 = f.read()
-	finally:
-		f.close()
 
 	# now store the revision unique number in waf
 	code1 = code1.replace("if sys.hexversion<0x206000f:\n\traise ImportError('Python >= 2.6 is required to create the waf file')\n", '')
@@ -363,11 +344,8 @@ def create_waf(self, *k, **kw):
 	elif zipType == 'xz':
 		code1 = code1.replace('bunzip2', 'xz -d')
 
-	f = open('%s.tar.%s' % (mw, zipType), 'rb')
-	try:
+	with open('%s.tar.%s' % (mw, zipType), 'rb') as f:
 		cnt = f.read()
-	finally:
-		f.close()
 
 	# the REVISION value is the md5 sum of the compressed data (facilitate audits)
 	m = md5()
@@ -396,8 +374,7 @@ def create_waf(self, *k, **kw):
 	if getattr(Options.options, 'interpreter', None):
 		ccc = ccc.replace('#!/usr/bin/env python', Options.options.interpreter)
 
-	f = open('waf', 'wb')
-	try:
+	with open('waf', 'wb') as f:
 		f.write(ccc.encode())
 		f.write(to_bytes('#==>\n#'))
 		f.write(cnt)
@@ -419,16 +396,11 @@ def create_waf(self, *k, **kw):
 			f.write(sig)
 			f.write('\n')
 			os.remove('waf.asc')
-	finally:
-		f.close()
 
 
 	if sys.platform == 'win32' or Options.options.make_batch:
-		f = open('waf.bat', 'w')
-		try:
+		with open('waf.bat', 'w') as f:
 			f.write('@setlocal\n@set PYEXE=python\n@where %PYEXE% 1>NUL 2>NUL\n@if %ERRORLEVEL% neq 0 set PYEXE=py\n@%PYEXE% -x "%~dp0waf" %*\n@exit /b %ERRORLEVEL%\n')
-		finally:
-			f.close()
 
 	if sys.platform != 'win32':
 		os.chmod('waf', Utils.O755)