Use context manager for file I/O.

There are a few cases where a context manager cannot be used, such as
the logger.

7 files changed, 76 insertions, 54 deletions

diff --git a/mesonbuild/scripts/meson_benchmark.py b/mesonbuild/scripts/meson_benchmark.py
index d1107b6..6d138b0 100644
--- a/mesonbuild/scripts/meson_benchmark.py
+++ b/mesonbuild/scripts/meson_benchmark.py
@@ -52,33 +52,34 @@ def run_benchmarks(options, datafile):
     failed_tests = 0
     logfile_base = 'meson-logs/benchmarklog'
     jsonlogfilename = logfile_base+ '.json'
-    jsonlogfile = open(jsonlogfilename, 'w')
-    tests = pickle.load(open(datafile, 'rb'))
+    with open(datafile, 'rb') as f:
+        tests = pickle.load(f)
     num_tests = len(tests)
     if num_tests == 0:
         print('No benchmarks defined.')
         return 0
     iteration_count = 5
     wrap = [] # Benchmarks on cross builds are pointless so don't support them.
-    for i, test in enumerate(tests):
-        runs = []
-        durations = []
-        failed = False
-        for _ in range(iteration_count):
-            res = meson_test.run_single_test(wrap, test)
-            runs.append(res)
-            durations.append(res.duration)
-            if res.returncode != 0:
-                failed = True
-        mean = statistics.mean(durations)
-        stddev = statistics.stdev(durations)
-        if failed:
-            resultstr = 'FAIL'
-            failed_tests += 1
-        else:
-            resultstr = 'OK'
-        print_stats(3, num_tests, test.name, resultstr, i, mean, stddev)
-        print_json_log(jsonlogfile, runs, test.name, i)
+    with open(jsonlogfilename, 'w') as jsonlogfile:
+        for i, test in enumerate(tests):
+            runs = []
+            durations = []
+            failed = False
+            for _ in range(iteration_count):
+                res = meson_test.run_single_test(wrap, test)
+                runs.append(res)
+                durations.append(res.duration)
+                if res.returncode != 0:
+                    failed = True
+            mean = statistics.mean(durations)
+            stddev = statistics.stdev(durations)
+            if failed:
+                resultstr = 'FAIL'
+                failed_tests += 1
+            else:
+                resultstr = 'OK'
+            print_stats(3, num_tests, test.name, resultstr, i, mean, stddev)
+            print_json_log(jsonlogfile, runs, test.name, i)
     print('\nFull log written to meson-logs/benchmarklog.json.')
     return failed_tests
 
diff --git a/mesonbuild/scripts/meson_exe.py b/mesonbuild/scripts/meson_exe.py
index 1a0fcda..d2ae357 100644
--- a/mesonbuild/scripts/meson_exe.py
+++ b/mesonbuild/scripts/meson_exe.py
@@ -74,7 +74,8 @@ def run(args):
         print('Test runner for Meson. Do not run on your own, mmm\'kay?')
         print(sys.argv[0] + ' [data file]')
     exe_data_file = options.args[0]
-    exe = pickle.load(open(exe_data_file, 'rb'))
+    with open(exe_data_file, 'rb') as f:
+        exe = pickle.load(f)
     return run_exe(exe)
 
 if __name__ == '__main__':
diff --git a/mesonbuild/scripts/meson_install.py b/mesonbuild/scripts/meson_install.py
index 1924b95..6e877cf 100644
--- a/mesonbuild/scripts/meson_install.py
+++ b/mesonbuild/scripts/meson_install.py
@@ -38,8 +38,8 @@ def do_copy(from_file, to_file):
     append_to_log(to_file)
 
 def do_install(datafilename):
-    ifile = open(datafilename, 'rb')
-    d = pickle.load(ifile)
+    with open(datafilename, 'rb') as ifile:
+        d = pickle.load(ifile)
     d.destdir = os.environ.get('DESTDIR', '')
     d.fullprefix = destdir_join(d.destdir, d.prefix)
 
@@ -112,7 +112,9 @@ def install_man(d):
         os.makedirs(outdir, exist_ok=True)
         print('Installing %s to %s.' % (full_source_filename, outdir))
         if outfilename.endswith('.gz') and not full_source_filename.endswith('.gz'):
-            open(outfilename, 'wb').write(gzip.compress(open(full_source_filename, 'rb').read()))
+            with open(outfilename, 'wb') as of:
+                with open(full_source_filename, 'rb') as sf:
+                    of.write(gzip.compress(sf.read()))
             shutil.copystat(full_source_filename, outfilename)
             append_to_log(outfilename)
         else:
@@ -142,7 +144,8 @@ def run_install_script(d):
         print('Running custom install script %s' % script)
         suffix = os.path.splitext(script)[1].lower()
         if platform.system().lower() == 'windows' and suffix != '.bat':
-            first_line = open(script, encoding='latin_1', errors='ignore').readline().strip()
+            with open(script, encoding='latin_1', errors='ignore') as f:
+                first_line = f.readline().strip()
             if first_line.startswith('#!'):
                 if shutil.which(first_line[2:]):
                     commands = [first_line[2:]]
diff --git a/mesonbuild/scripts/meson_test.py b/mesonbuild/scripts/meson_test.py
index 33b6165..951fb85 100644
--- a/mesonbuild/scripts/meson_test.py
+++ b/mesonbuild/scripts/meson_test.py
@@ -202,10 +202,8 @@ def run_tests(datafilename):
         wrap = [options.wrapper]
         logfilename = logfile_base + '-' + options.wrapper.replace(' ', '_') + '.txt'
         jsonlogfilename = logfile_base + '-' + options.wrapper.replace(' ', '_') + '.json'
-    logfile = open(logfilename, 'w')
-    jsonlogfile = open(jsonlogfilename, 'w')
-    logfile.write('Log of Meson test suite run on %s.\n\n' % datetime.datetime.now().isoformat())
-    tests = pickle.load(open(datafilename, 'rb'))
+    with open(datafilename, 'rb') as f:
+        tests = pickle.load(f)
     if len(tests) == 0:
         print('No tests defined.')
         return
@@ -222,24 +220,31 @@ def run_tests(datafilename):
     executor = conc.ThreadPoolExecutor(max_workers=num_workers)
     futures = []
     filtered_tests = filter_tests(options.suite, tests)
-    for i, test in enumerate(filtered_tests):
-        if test.suite[0] == '':
-            visible_name = test.name
-        else:
-            if options.suite is not None:
-                visible_name = options.suite + ' / ' + test.name
+
+    with open(jsonlogfilename, 'w') as jsonlogfile, \
+         open(logfilename, 'w') as logfile:
+        logfile.write('Log of Meson test suite run on %s.\n\n' %
+                      datetime.datetime.now().isoformat())
+        for i, test in enumerate(filtered_tests):
+            if test.suite[0] == '':
+                visible_name = test.name
             else:
-                visible_name = test.suite[0] + ' / ' + test.name
+                if options.suite is not None:
+                    visible_name = options.suite + ' / ' + test.name
+                else:
+                    visible_name = test.suite[0] + ' / ' + test.name
 
-        if not test.is_parallel:
-            drain_futures(futures)
-            futures = []
-            res = run_single_test(wrap, test)
-            print_stats(numlen, filtered_tests, visible_name, res, i, logfile, jsonlogfile)
-        else:
-            f = executor.submit(run_single_test, wrap, test)
-            futures.append((f, numlen, filtered_tests, visible_name, i, logfile, jsonlogfile))
-    drain_futures(futures)
+            if not test.is_parallel:
+                drain_futures(futures)
+                futures = []
+                res = run_single_test(wrap, test)
+                print_stats(numlen, filtered_tests, visible_name, res, i,
+                            logfile, jsonlogfile)
+            else:
+                f = executor.submit(run_single_test, wrap, test)
+                futures.append((f, numlen, filtered_tests, visible_name, i,
+                                logfile, jsonlogfile))
+        drain_futures(futures)
     return logfilename
 
 def run(args):
diff --git a/mesonbuild/scripts/regen_checker.py b/mesonbuild/scripts/regen_checker.py
index f65f3bd..ddf4943 100644
--- a/mesonbuild/scripts/regen_checker.py
+++ b/mesonbuild/scripts/regen_checker.py
@@ -48,8 +48,10 @@ def run(args):
     private_dir = args[0]
     dumpfile = os.path.join(private_dir, 'regeninfo.dump')
     coredata = os.path.join(private_dir, 'coredata.dat')
-    regeninfo = pickle.load(open(dumpfile, 'rb'))
-    coredata = pickle.load(open(coredata, 'rb'))
+    with open(dumpfile, 'rb') as f:
+        regeninfo = pickle.load(f)
+    with open(coredata, 'rb') as f:
+        coredata = pickle.load(f)
     mesonscript = coredata.meson_script_file
     backend = coredata.get_builtin_option('backend')
     regen_timestamp = os.stat(dumpfile).st_mtime
diff --git a/mesonbuild/scripts/symbolextractor.py b/mesonbuild/scripts/symbolextractor.py
index 79c1264..c117301 100644
--- a/mesonbuild/scripts/symbolextractor.py
+++ b/mesonbuild/scripts/symbolextractor.py
@@ -34,16 +34,19 @@ parser.add_argument('args', nargs='+')
 
 def dummy_syms(outfilename):
     """Just touch it so relinking happens always."""
-    open(outfilename, 'w').close()
+    with open(outfilename, 'w'):
+        pass
 
 def write_if_changed(text, outfilename):
     try:
-        oldtext = open(outfilename, 'r').read()
+        with open(outfilename, 'r') as f:
+            oldtext = f.read()
         if text == oldtext:
             return
     except FileNotFoundError:
         pass
-    open(outfilename, 'w').write(text)
+    with open(outfilename, 'w') as f:
+        f.write(text)
 
 def linux_syms(libfilename, outfilename):
     pe = subprocess.Popen(['readelf', '-d', libfilename], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
diff --git a/mesonbuild/scripts/vcstagger.py b/mesonbuild/scripts/vcstagger.py
index 390e37a..3f36e0a 100644
--- a/mesonbuild/scripts/vcstagger.py
+++ b/mesonbuild/scripts/vcstagger.py
@@ -23,9 +23,16 @@ def config_vcs_tag(infile, outfile, fallback, source_dir, replace_string, regex_
     except Exception:
         new_string = fallback
 
-    new_data = open(infile).read().replace(replace_string, new_string)
-    if (not os.path.exists(outfile)) or (open(outfile).read() != new_data):
-        open(outfile, 'w').write(new_data)
+    with open(infile) as f:
+        new_data = f.read().replace(replace_string, new_string)
+    if os.path.exists(outfile):
+        with open(outfile) as f:
+            needs_update = (f.read() != new_data)
+    else:
+        needs_update = True
+    if needs_update:
+        with open(outfile, 'w') as f:
+            f.write(new_data)
 
 def run(args):
     infile, outfile, fallback, source_dir, replace_string, regex_selector = args[0:6]