Use context manager for file I/O.

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

mesonbuild/backend/backends.py

@@ -139,24 +139,34 @@ class Backend():
         langlist = {}
         abs_files = []
         result = []
-        for src in unity_src:
-            comp = self.get_compiler_for_source(src, target.is_cross)
-            language = comp.get_language()
-            suffix = '.' + comp.get_default_suffix()
-            if language not in langlist:
-                outfilename = os.path.join(self.get_target_private_dir_abs(target), target.name + '-unity' + suffix)
-                outfileabs = os.path.join(self.environment.get_build_dir(), outfilename)
+
+        def init_language_file(language, suffix):
+            outfilename = os.path.join(self.get_target_private_dir_abs(target),
+                                       target.name + '-unity' + suffix)
+            outfileabs = os.path.join(self.environment.get_build_dir(),
+                                      outfilename)
             outfileabs_tmp = outfileabs + '.tmp'
             abs_files.append(outfileabs)
             outfileabs_tmp_dir = os.path.dirname(outfileabs_tmp)
             if not os.path.exists(outfileabs_tmp_dir):
                 os.makedirs(outfileabs_tmp_dir)
-                outfile = open(outfileabs_tmp, 'w')
-                langlist[language] = outfile
             result.append(outfilename)
+            return open(outfileabs_tmp, 'w')
+
+        try:
+            for src in unity_src:
+                comp = self.get_compiler_for_source(src, target.is_cross)
+                language = comp.get_language()
+                try:
                     ofile = langlist[language]
+                except KeyError:
+                    suffix = '.' + comp.get_default_suffix()
+                    ofile = langlist[language] = init_language_file(language,
+                                                                    suffix)
                 ofile.write('#include<%s>\n' % src)
-        [x.close() for x in langlist.values()]
+        finally:
+            for x in langlist.values():
+                x.close()
         [mesonlib.replace_if_different(x, x + '.tmp') for x in abs_files]
         return result
 
@@ -215,13 +225,11 @@ class Backend():
 
     def serialise_tests(self):
         test_data = os.path.join(self.environment.get_scratch_dir(), 'meson_test_setup.dat')
-        datafile = open(test_data, 'wb')
+        with open(test_data, 'wb') as datafile:
             self.write_test_file(datafile)
-        datafile.close()
         benchmark_data = os.path.join(self.environment.get_scratch_dir(), 'meson_benchmark_setup.dat')
-        datafile = open(benchmark_data, 'wb')
+        with open(benchmark_data, 'wb') as datafile:
             self.write_benchmark_file(datafile)
-        datafile.close()
         return (test_data, benchmark_data)
 
     def has_source_suffix(self, target, suffix):
@@ -442,7 +450,8 @@ class Backend():
         mfobj = {'type': 'dependency manifest',
                  'version': '1.0'}
         mfobj['projects'] = self.build.dep_manifest
-        open(ifilename, 'w').write(json.dumps(mfobj))
+        with open(ifilename, 'w') as f:
+            f.write(json.dumps(mfobj))
         d.data.append([ifilename, ofilename])
 
     def get_regen_filelist(self):

mesonbuild/backend/ninjabackend.py

@@ -133,17 +133,18 @@ class NinjaBackend(backends.Backend):
         self.all_outputs = {}
         self.valgrind = environment.find_valgrind()
 
-    def detect_vs_dep_prefix(self, outfile, tempfilename):
+    def detect_vs_dep_prefix(self, tempfilename):
         '''VS writes its dependency in a locale dependent format.
         Detect the search prefix to use.'''
         # Of course there is another program called 'cl' on
         # some platforms. Let's just require that on Windows
         # cl points to msvc.
         if not mesonlib.is_windows() or shutil.which('cl') is None:
-            return outfile
-        outfile.close()
-        open(os.path.join(self.environment.get_scratch_dir(), 'incdetect.c'),
-              'w').write('''#include<stdio.h>
+            return open(tempfilename, 'a')
+        filename = os.path.join(self.environment.get_scratch_dir(),
+                                'incdetect.c')
+        with open(filename, 'w') as f:
+            f.write('''#include<stdio.h>
 int dummy;
 ''')
 
@@ -157,9 +158,8 @@ int dummy;
         for line in stdo.split(b'\r\n'):
             if line.endswith(b'stdio.h'):
                 matchstr = b':'.join(line.split(b':')[0:2]) + b':'
-                binfile = open(tempfilename, 'ab')
+                with open(tempfilename, 'ab') as binfile:
                     binfile.write(b'msvc_deps_prefix = ' + matchstr + b'\r\n')
-                binfile.close()
                 return open(tempfilename, 'a')
         raise MesonException('Could not determine vs dep dependency prefix string.')
 
@@ -167,16 +167,18 @@ int dummy;
         self.interpreter = interp
         outfilename = os.path.join(self.environment.get_build_dir(), self.ninja_filename)
         tempfilename = outfilename + '~'
-        outfile = open(tempfilename, 'w')
-        outfile.write('# This is the build file for project "%s"\n' % self.build.get_project())
+        with open(tempfilename, 'w') as outfile:
+            outfile.write('# This is the build file for project "%s"\n' %
+                          self.build.get_project())
             outfile.write('# It is autogenerated by the Meson build system.\n')
             outfile.write('# Do not edit by hand.\n\n')
             outfile.write('ninja_required_version = 1.5.1\n\n')
-        outfile = self.detect_vs_dep_prefix(outfile, tempfilename)
+        with self.detect_vs_dep_prefix(tempfilename) as outfile:
             self.generate_rules(outfile)
             self.generate_phony(outfile)
             outfile.write('# Build rules for targets\n\n')
-        [self.generate_target(t, outfile) for t in self.build.get_targets().values()]
+            for t in self.build.get_targets().values():
+                self.generate_target(t, outfile)
             outfile.write('# Test rules\n\n')
             self.generate_tests(outfile)
             outfile.write('# Install rules\n\n')
@@ -190,7 +192,6 @@ int dummy;
             self.generate_ending(outfile)
         # Only ovewrite the old build file after the new one has been
         # fully created.
-        outfile.close()
         os.replace(tempfilename, outfilename)
         self.generate_compdb()
 
@@ -202,7 +203,8 @@ int dummy;
             jsondb = subprocess.check_output([ninja_exe, '-t', 'compdb', 'c_COMPILER', 'cpp_COMPILER'], cwd=builddir)
         except Exception:
                 raise MesonException('Could not create compilation database.')
-        open(os.path.join(builddir, 'compile_commands.json'), 'wb').write(jsondb)
+        with open(os.path.join(builddir, 'compile_commands.json'), 'wb') as f:
+            f.write(jsondb)
 
     # Get all generated headers. Any source file might need them so
     # we need to add an order dependency to them.
@@ -505,7 +507,7 @@ int dummy;
         self.generate_subdir_install(d)
         elem.write(outfile)
 
-        ofile = open(install_data_file, 'wb')
+        with open(install_data_file, 'wb') as ofile:
             pickle.dump(d, ofile)
 
     def generate_target_install(self, d):
@@ -1416,14 +1418,20 @@ rule FORTRAN_DEP_HACK
             # but those are really rare. I hope.
             if not compiler.can_compile(s):
                 continue
-            for line in open(os.path.join(self.environment.get_source_dir(), s.subdir, s.fname)):
+            filename = os.path.join(self.environment.get_source_dir(),
+                                    s.subdir, s.fname)
+            with open(filename) as f:
+                for line in f:
                     modmatch = modre.match(line)
                     if modmatch is not None:
                         modname = modmatch.group(1)
-                    if modname.lower() == 'procedure': # MODULE PROCEDURE construct
+                        if modname.lower() == 'procedure':
+                            # MODULE PROCEDURE construct
                             continue
                         if modname in module_files:
-                        raise InvalidArguments('Namespace collision: module %s defined in two files %s and %s.' %
+                            raise InvalidArguments(
+                                'Namespace collision: module %s defined in '
+                                'two files %s and %s.' %
                                     (modname, module_files[modname], s))
                         module_files[modname] = s
         self.fortran_deps[target.get_basename()] = module_files
@@ -1433,18 +1441,22 @@ rule FORTRAN_DEP_HACK
         usere = re.compile(r"\s*use\s+(\w+)", re.IGNORECASE)
         dirname = self.get_target_private_dir(target)
         tdeps= self.fortran_deps[target.get_basename()]
-        for line in open(src):
+        with open(src) as f:
+            for line in f:
                 usematch = usere.match(line)
                 if usematch is not None:
                     usename = usematch.group(1)
                     if usename not in tdeps:
-                    # The module is not provided by any source file. This is due to
+                        # The module is not provided by any source file. This
+                        # is due to:
                         #   a) missing file/typo/etc
-                    # b) using a module provided by the compiler, such as OpenMP
-                    # There's no easy way to tell which is which (that I know of)
-                    # so just ignore this and go on. Ideally we would print a
-                    # warning message to the user but this is a common occurrance,
-                    # which would lead to lots of distracting noise.
+                        #   b) using a module provided by the compiler, such as
+                        #      OpenMP
+                        # There's no easy way to tell which is which (that I
+                        # know of) so just ignore this and go on. Ideally we
+                        # would print a warning message to the user but this is
+                        # a common occurrence, which would lead to lots of
+                        # distracting noise.
                         continue
                     mod_source_file = tdeps[usename]
                     # Check if a source uses a module it exports itself.
@@ -1452,7 +1464,8 @@ rule FORTRAN_DEP_HACK
                     # the same name.
                     if mod_source_file.fname == os.path.split(src)[1]:
                         continue
-                mod_name = compiler.module_name_to_filename(usematch.group(1))
+                    mod_name = compiler.module_name_to_filename(
+                        usematch.group(1))
                     mod_files.append(os.path.join(dirname, mod_name))
         return mod_files
 

mesonbuild/backend/vs2010backend.py

@@ -175,14 +175,18 @@ class Vs2010Backend(backends.Backend):
 
     @staticmethod
     def touch_regen_timestamp(build_dir):
-        open(Vs2010Backend.get_regen_stampfile(build_dir), 'w').close()
+        with open(Vs2010Backend.get_regen_stampfile(build_dir), 'w'):
+            pass
 
     def generate_regen_info(self):
         deps = self.get_regen_filelist()
         regeninfo = RegenInfo(self.environment.get_source_dir(),
                               self.environment.get_build_dir(),
                               deps)
-        pickle.dump(regeninfo, open(os.path.join(self.environment.get_scratch_dir(), 'regeninfo.dump'), 'wb'))
+        filename = os.path.join(self.environment.get_scratch_dir(),
+                                'regeninfo.dump')
+        with open(filename, 'wb') as f:
+            pickle.dump(regeninfo, f)
 
     def get_obj_target_deps(self, obj_list):
         result = {}
@@ -217,15 +221,18 @@ class Vs2010Backend(backends.Backend):
         return all_deps
 
     def generate_solution(self, sln_filename, projlist):
-        ofile = open(sln_filename, 'w')
-        ofile.write('Microsoft Visual Studio Solution File, Format Version 11.00\n')
+        with open(sln_filename, 'w') as ofile:
+            ofile.write('Microsoft Visual Studio Solution File, Format '
+                        'Version 11.00\n')
             ofile.write('# Visual Studio ' + self.vs_version + '\n')
             prj_templ = prj_line = 'Project("{%s}") = "%s", "%s", "{%s}"\n'
             for p in projlist:
-            prj_line = prj_templ % (self.environment.coredata.guid, p[0], p[1], p[2])
+                prj_line = prj_templ % (self.environment.coredata.guid,
+                                        p[0], p[1], p[2])
                 ofile.write(prj_line)
                 all_deps = self.determine_deps(p)
-            ofile.write('\tProjectSection(ProjectDependencies) = postProject\n')
+                ofile.write('\tProjectSection(ProjectDependencies) = '
+                            'postProject\n')
                 regen_guid = self.environment.coredata.regen_guid
                 ofile.write('\t\t{%s} = {%s}\n' % (regen_guid, regen_guid))
                 for dep in all_deps.keys():
@@ -234,24 +241,30 @@ class Vs2010Backend(backends.Backend):
                 ofile.write('EndProjectSection\n')
                 ofile.write('EndProject\n')
             test_line = prj_templ % (self.environment.coredata.guid,
-                                 'RUN_TESTS', 'RUN_TESTS.vcxproj', self.environment.coredata.test_guid)
+                                     'RUN_TESTS', 'RUN_TESTS.vcxproj',
+                                     self.environment.coredata.test_guid)
             ofile.write(test_line)
             ofile.write('EndProject\n')
             regen_line = prj_templ % (self.environment.coredata.guid,
-                                 'REGEN', 'REGEN.vcxproj', self.environment.coredata.regen_guid)
+                                      'REGEN', 'REGEN.vcxproj',
+                                      self.environment.coredata.regen_guid)
             ofile.write(regen_line)
             ofile.write('EndProject\n')
             ofile.write('Global\n')
-        ofile.write('\tGlobalSection(SolutionConfigurationPlatforms) = preSolution\n')
-        ofile.write('\t\t%s|%s = %s|%s\n' % (self.buildtype, self.platform, self.buildtype, self.platform))
+            ofile.write('\tGlobalSection(SolutionConfigurationPlatforms) = '
+                        'preSolution\n')
+            ofile.write('\t\t%s|%s = %s|%s\n' %
+                        (self.buildtype, self.platform, self.buildtype,
+                         self.platform))
             ofile.write('\tEndGlobalSection\n')
-        ofile.write('\tGlobalSection(ProjectConfigurationPlatforms) = postSolution\n')
+            ofile.write('\tGlobalSection(ProjectConfigurationPlatforms) = '
+                        'postSolution\n')
             ofile.write('\t\t{%s}.%s|%s.ActiveCfg = %s|%s\n' % 
-                    (self.environment.coredata.regen_guid, self.buildtype, self.platform,
-                     self.buildtype, self.platform))
+                        (self.environment.coredata.regen_guid, self.buildtype,
+                         self.platform, self.buildtype, self.platform))
             ofile.write('\t\t{%s}.%s|%s.Build.0 = %s|%s\n' %
-                    (self.environment.coredata.regen_guid, self.buildtype, self.platform,
-                     self.buildtype, self.platform))
+                        (self.environment.coredata.regen_guid, self.buildtype,
+                         self.platform, self.buildtype, self.platform))
             for p in projlist:
                 ofile.write('\t\t{%s}.%s|%s.ActiveCfg = %s|%s\n' %
                             (p[2], self.buildtype, self.platform,
@@ -261,8 +274,8 @@ class Vs2010Backend(backends.Backend):
                                 (p[2], self.buildtype, self.platform,
                                  self.buildtype, self.platform))
             ofile.write('\t\t{%s}.%s|%s.ActiveCfg = %s|%s\n' %
-                    (self.environment.coredata.test_guid, self.buildtype, self.platform,
-                     self.buildtype, self.platform))
+                        (self.environment.coredata.test_guid, self.buildtype,
+                         self.platform, self.buildtype, self.platform))
             ofile.write('\tEndGlobalSection\n')
             ofile.write('\tGlobalSection(SolutionProperties) = preSolution\n')
             ofile.write('\t\tHideSolutionNode = FALSE\n')
@@ -862,12 +875,15 @@ class Vs2010Backend(backends.Backend):
         tree.write(ofname, encoding='utf-8', xml_declaration=True)
         # ElementTree can not do prettyprinting so do it manually
         doc = xml.dom.minidom.parse(ofname)
-        open(ofname, 'w').write(doc.toprettyxml())
+        with open(ofname, 'w') as of:
+            of.write(doc.toprettyxml())
         # World of horror! Python insists on not quoting quotes and
         # fixing the escaped " into " whereas MSVS
         # requires quoted but not fixed elements. Enter horrible hack.
-        txt = open(ofname, 'r').read()
-        open(ofname, 'w').write(txt.replace('"', '"'))
+        with open(ofname, 'r') as of:
+            txt = of.read()
+        with open(ofname, 'w') as of:
+            of.write(txt.replace('"', '"'))
 
     def gen_regenproj(self, project_name, ofname):
         root = ET.Element('Project', {'DefaultTargets': 'Build',

mesonbuild/backend/xcodebackend.py

@@ -82,7 +82,7 @@ class XCodeBackend(backends.Backend):
         self.proj_dir = os.path.join(self.environment.get_build_dir(), self.build.project_name + '.xcodeproj')
         os.makedirs(self.proj_dir, exist_ok=True)
         self.proj_file = os.path.join(self.proj_dir, 'project.pbxproj')
-        self.ofile = open(self.proj_file, 'w')
+        with open(self.proj_file, 'w') as self.ofile:
             self.generate_prefix()
             self.generate_pbx_aggregate_target()
             self.generate_pbx_build_file()
@@ -99,10 +99,6 @@ class XCodeBackend(backends.Backend):
             self.generate_xc_configurationList()
             self.generate_suffix()
 
-        # for some reason, the entire file was not being flushed to the disk.
-        # closing it explicitly forces a flush and fixes the issue
-        self.ofile.close()
-
     def get_xcodetype(self, fname):
         return self.xcodetypemap[fname.split('.')[-1]]
 

mesonbuild/compilers.py

@@ -538,9 +538,8 @@ class CCompiler(Compiler):
         binname += '.exe'
         # Write binary check source
         binary_name = os.path.join(work_dir, binname)
-        ofile = open(source_name, 'w')
+        with open(source_name, 'w') as ofile:
             ofile.write(code)
-        ofile.close()
         # Compile sanity check
         cmdlist = self.exelist + extra_flags + [source_name] + self.get_output_args(binary_name)
         pc = subprocess.Popen(cmdlist, stdout=subprocess.PIPE, stderr=subprocess.PIPE, cwd=work_dir)
@@ -617,9 +616,8 @@ int main () {{ {1}; }}'''
         suflen = len(self.default_suffix)
         (fd, srcname) = tempfile.mkstemp(suffix='.'+self.default_suffix)
         os.close(fd)
-        ofile = open(srcname, 'w')
+        with open(srcname, 'w') as ofile:
             ofile.write(code)
-        ofile.close()
         # Convert flags to the native type of the selected compiler
         args = self.unix_link_flags_to_native(extra_args)
         # Read c_args/cpp_args/etc from the cross-info file (if needed)
@@ -647,9 +645,8 @@ int main () {{ {1}; }}'''
         os.close(fd)
         (fd, dstname) = tempfile.mkstemp()
         os.close(fd)
-        ofile = open(srcname, 'w')
+        with open(srcname, 'w') as ofile:
             ofile.write(code)
-        ofile.close()
         # Convert flags to the native type of the selected compiler
         args = self.unix_link_flags_to_native(extra_args)
         # Select a CRT if needed since we're linking
@@ -672,9 +669,8 @@ int main () {{ {1}; }}'''
             raise CrossNoRunException('Can not run test applications in this cross environment.')
         (fd, srcname) = tempfile.mkstemp(suffix='.'+self.default_suffix)
         os.close(fd)
-        ofile = open(srcname, 'w')
+        with open(srcname, 'w') as ofile:
             ofile.write(code)
-        ofile.close()
         # Convert flags to the native type of the selected compiler
         args = self.unix_link_flags_to_native(extra_args)
         # Select a CRT if needed since we're linking
@@ -997,9 +993,9 @@ class ObjCCompiler(CCompiler):
         extra_flags = self.get_cross_extra_flags(environment, compile=True, link=False)
         if self.is_cross:
             extra_flags += self.get_compile_only_args()
-        ofile = open(source_name, 'w')
-        ofile.write('#import<stdio.h>\nint main(int argc, char **argv) { return 0; }\n')
-        ofile.close()
+        with open(source_name, 'w') as ofile:
+            ofile.write('#import<stdio.h>\n'
+                        'int main(int argc, char **argv) { return 0; }\n')
         pc = subprocess.Popen(self.exelist + extra_flags + [source_name, '-o', binary_name])
         pc.wait()
         if pc.returncode != 0:
@@ -1031,9 +1027,10 @@ class ObjCPPCompiler(CPPCompiler):
         extra_flags = self.get_cross_extra_flags(environment, compile=True, link=False)
         if self.is_cross:
             extra_flags += self.get_compile_only_args()
-        ofile = open(source_name, 'w')
-        ofile.write('#import<stdio.h>\nclass MyClass;int main(int argc, char **argv) { return 0; }\n')
-        ofile.close()
+        with open(source_name, 'w') as ofile:
+            ofile.write('#import<stdio.h>\n'
+                        'class MyClass;'
+                        'int main(int argc, char **argv) { return 0; }\n')
         pc = subprocess.Popen(self.exelist + extra_flags + [source_name, '-o', binary_name])
         pc.wait()
         if pc.returncode != 0:
@@ -1133,13 +1130,12 @@ class MonoCompiler(Compiler):
         src = 'sanity.cs'
         obj = 'sanity.exe'
         source_name = os.path.join(work_dir, src)
-        ofile = open(source_name, 'w')
+        with open(source_name, 'w') as ofile:
             ofile.write('''public class Sanity {
     static public void Main () {
     }
 }
 ''')
-        ofile.close()
         pc = subprocess.Popen(self.exelist + [src], cwd=work_dir)
         pc.wait()
         if pc.returncode != 0:
@@ -1245,14 +1241,13 @@ class JavaCompiler(Compiler):
         src = 'SanityCheck.java'
         obj = 'SanityCheck'
         source_name = os.path.join(work_dir, src)
-        ofile = open(source_name, 'w')
+        with open(source_name, 'w') as ofile:
             ofile.write('''class SanityCheck {
   public static void main(String[] args) {
     int i;
   }
 }
 ''')
-        ofile.close()
         pc = subprocess.Popen(self.exelist + [src], cwd=work_dir)
         pc.wait()
         if pc.returncode != 0:
@@ -1292,11 +1287,10 @@ class ValaCompiler(Compiler):
     def sanity_check(self, work_dir, environment):
         src = 'valatest.vala'
         source_name = os.path.join(work_dir, src)
-        ofile = open(source_name, 'w')
+        with open(source_name, 'w') as ofile:
             ofile.write('''class SanityCheck : Object {
 }
 ''')
-        ofile.close()
         extra_flags = self.get_cross_extra_flags(environment, compile=True, link=False)
         pc = subprocess.Popen(self.exelist + extra_flags + ['-C', '-c', src], cwd=work_dir)
         pc.wait()
@@ -1336,11 +1330,10 @@ class RustCompiler(Compiler):
     def sanity_check(self, work_dir, environment):
         source_name = os.path.join(work_dir, 'sanity.rs')
         output_name = os.path.join(work_dir, 'rusttest')
-        ofile = open(source_name, 'w')
+        with open(source_name, 'w') as ofile:
             ofile.write('''fn main() {
 }
 ''')
-        ofile.close()
         pc = subprocess.Popen(self.exelist + ['-o', output_name, source_name], cwd=work_dir)
         pc.wait()
         if pc.returncode != 0:
@@ -1435,10 +1428,9 @@ class SwiftCompiler(Compiler):
         src = 'swifttest.swift'
         source_name = os.path.join(work_dir, src)
         output_name = os.path.join(work_dir, 'swifttest')
-        ofile = open(source_name, 'w')
+        with open(source_name, 'w') as ofile:
             ofile.write('''1 + 2
 ''')
-        ofile.close()
         extra_flags = self.get_cross_extra_flags(environment, compile=True, link=True)
         pc = subprocess.Popen(self.exelist + extra_flags + ['-emit-executable', '-o', output_name, src], cwd=work_dir)
         pc.wait()
@@ -1461,11 +1453,10 @@ class DCompiler(Compiler):
     def sanity_check(self, work_dir, environment):
         source_name = os.path.join(work_dir, 'sanity.d')
         output_name = os.path.join(work_dir, 'dtest')
-        ofile = open(source_name, 'w')
+        with open(source_name, 'w') as ofile:
             ofile.write('''void main() {
 }
 ''')
-        ofile.close()
         pc = subprocess.Popen(self.exelist + self.get_output_args(output_name) + [source_name], cwd=work_dir)
         pc.wait()
         if pc.returncode != 0:
@@ -1872,9 +1863,8 @@ class VisualStudioCCompiler(CCompiler):
         code = 'int i;\n'
         (fd, srcname) = tempfile.mkstemp(suffix='.'+self.default_suffix)
         os.close(fd)
-        ofile = open(srcname, 'w')
+        with open(srcname, 'w') as ofile:
             ofile.write(code)
-        ofile.close()
         # Read c_args/cpp_args/etc from the cross-info file (if needed)
         extra_args = self.get_cross_extra_flags(env, compile=True, link=False)
         extra_args += self.get_compile_only_args()
@@ -2286,12 +2276,11 @@ class FortranCompiler(Compiler):
     def sanity_check(self, work_dir, environment):
         source_name = os.path.join(work_dir, 'sanitycheckf.f90')
         binary_name = os.path.join(work_dir, 'sanitycheckf')
-        ofile = open(source_name, 'w')
+        with open(source_name, 'w') as ofile:
             ofile.write('''program prog
      print *, "Fortran compilation is working."
 end program prog
 ''')
-        ofile.close()
         extra_flags = self.get_cross_extra_flags(environment, compile=True, link=True)
         pc = subprocess.Popen(self.exelist + extra_flags + [source_name, '-o', binary_name])
         pc.wait()

mesonbuild/coredata.py

@@ -154,7 +154,8 @@ class CoreData():
             raise RuntimeError('Tried to set unknown builtin option %s.' % optname)
 
 def load(filename):
-    obj = pickle.load(open(filename, 'rb'))
+    with open(filename, 'rb') as f:
+        obj = pickle.load(f)
     if not isinstance(obj, CoreData):
         raise RuntimeError('Core data file is corrupted.')
     if obj.version != version:
@@ -165,7 +166,8 @@ def load(filename):
 def save(obj, filename):
     if obj.version != version:
         raise RuntimeError('Fatal version mismatch corruption.')
-    pickle.dump(obj, open(filename, 'wb'))
+    with open(filename, 'wb') as f:
+        pickle.dump(obj, f)
 
 def get_builtin_options():
     return list(builtin_options.keys())

mesonbuild/dependencies.py

@@ -228,7 +228,8 @@ class PkgConfigDependency(Dependency):
         return self.is_found
 
     def extract_field(self, la_file, fieldname):
-        for line in open(la_file):
+        with open(la_file) as f:
+            for line in f:
                 arr = line.strip().split('=')
                 if arr[0] == fieldname:
                     return arr[1][1:-1]
@@ -374,7 +375,8 @@ class ExternalProgram():
         shebang and manually parse it to figure out the interpreter to use
         """
         try:
-            first_line = open(script).readline().strip()
+            with open(script) as f:
+                first_line = f.readline().strip()
             if first_line.startswith('#!'):
                 commands = first_line[2:].split('#')[0].strip().split()
                 if mesonlib.is_windows():
@@ -552,6 +554,7 @@ class BoostDependency(Dependency):
         except FileNotFoundError:
             self.version = None
             return
+        with ifile:
             for line in ifile:
                 if line.startswith("#define") and 'BOOST_LIB_VERSION' in line:
                     ver = line.split()[-1]

mesonbuild/interpreter.py

@@ -1032,7 +1032,8 @@ class Interpreter():
         mesonfile = os.path.join(self.source_root, self.subdir, environment.build_filename)
         if not os.path.isfile(mesonfile):
             raise InvalidArguments('Missing Meson file in %s' % mesonfile)
-        code = open(mesonfile, encoding='utf8').read()
+        with open(mesonfile, encoding='utf8') as mf:
+           code = mf.read()
         if len(code.strip()) == 0:
             raise InvalidCode('Builder file is empty.')
         assert(isinstance(code, str))
@@ -1994,7 +1995,8 @@ class Interpreter():
         if not os.path.isfile(absname):
             self.subdir = prev_subdir
             raise InterpreterException('Nonexistant build def file %s.' % buildfilename)
-        code = open(absname, encoding='utf8').read()
+        with open(absname, encoding='utf8') as f:
+            code = f.read()
         assert(isinstance(code, str))
         try:
             codeblock = mparser.Parser(code).parse()

mesonbuild/mconf.py

@@ -36,15 +36,18 @@ class Conf:
         self.build_file = os.path.join(build_dir, 'meson-private/build.dat')
         if not os.path.isfile(self.coredata_file) or not os.path.isfile(self.build_file):
             raise ConfException('Directory %s does not seem to be a Meson build directory.' % build_dir)
-        self.coredata = pickle.load(open(self.coredata_file, 'rb'))
-        self.build = pickle.load(open(self.build_file, 'rb'))
+        with open(self.coredata_file, 'rb') as f:
+            self.coredata = pickle.load(f)
+        with open(self.build_file, 'rb') as f:
+            self.build = pickle.load(f)
         if self.coredata.version != coredata.version:
             raise ConfException('Version mismatch (%s vs %s)' %
                                 (coredata.version, self.coredata.version))
 
     def save(self):
         # Only called if something has changed so overwrite unconditionally.
-        pickle.dump(self.coredata, open(self.coredata_file, 'wb'))
+        with open(self.coredata_file, 'wb') as f:
+            pickle.dump(self.coredata, f)
         # We don't write the build file because any changes to it
         # are erased when Meson is executed the nex time, i.e. the next
         # time Ninja is run.

mesonbuild/mesonlib.py

@@ -96,7 +96,8 @@ def is_32bit():
 
 def is_debianlike():
     try:
-        open('/etc/debian_version', 'r')
+        with open('/etc/debian_version', 'r'):
+            pass
         return True
     except FileNotFoundError:
         return False
@@ -262,7 +263,8 @@ def do_mesondefine(line, confdata):
 
 def do_conf_file(src, dst, confdata):
     try:
-        data = open(src).readlines()
+        with open(src) as f:
+            data = f.readlines()
     except Exception:
         raise MesonException('Could not read input file %s.' % src)
     # Only allow (a-z, A-Z, 0-9, _, -) as valid characters for a define
@@ -276,7 +278,8 @@ def do_conf_file(src, dst, confdata):
             line = do_replacement(regex, line, confdata)
         result.append(line)
     dst_tmp = dst + '~'
-    open(dst_tmp, 'w').writelines(result)
+    with open(dst_tmp, 'w') as f:
+        f.writelines(result)
     shutil.copymode(src, dst_tmp)
     replace_if_different(dst, dst_tmp)
 
@@ -306,7 +309,8 @@ def replace_if_different(dst, dst_tmp):
     # If contents are identical, don't touch the file to prevent
     # unnecessary rebuilds.
     try:
-        if open(dst, 'r').read() == open(dst_tmp, 'r').read():
+        with open(dst, 'r') as f1, open(dst_tmp, 'r') as f2:
+            if f1.read() == f2.read():
                 os.unlink(dst_tmp)
                 return
     except FileNotFoundError:

mesonbuild/mesonmain.py

@@ -169,7 +169,8 @@ itself as required.'''
         g.generate(intr)
         g.run_postconf_scripts()
         dumpfile = os.path.join(env.get_scratch_dir(), 'build.dat')
-        pickle.dump(b, open(dumpfile, 'wb'))
+        with open(dumpfile, 'wb') as f:
+            pickle.dump(b, f)
         # Write this last since we use the existence of this file to check if
         # we generated the build file successfully, so we don't want an error
         # that pops up during generation, post-conf scripts, etc to cause us to

mesonbuild/mintro.py

@@ -177,10 +177,14 @@ def run(args):
     buildfile = os.path.join(bdir, 'meson-private/build.dat')
     testfile = os.path.join(bdir, 'meson-private/meson_test_setup.dat')
     benchmarkfile = os.path.join(bdir, 'meson-private/meson_benchmark_setup.dat')
-    coredata = pickle.load(open(corefile, 'rb'))
-    builddata = pickle.load(open(buildfile, 'rb'))
-    testdata = pickle.load(open(testfile, 'rb'))
-    benchmarkdata = pickle.load(open(benchmarkfile, 'rb'))
+    with open(corefile, 'rb') as f:
+        coredata = pickle.load(f)
+    with open(buildfile, 'rb') as f:
+        builddata = pickle.load(f)
+    with open(testfile, 'rb') as f:
+       testdata = pickle.load(f)
+    with open(benchmarkfile, 'rb') as f:
+       benchmarkdata = pickle.load(f)
     if options.list_targets:
         list_targets(coredata, builddata)
     elif options.target_files is not None:

mesonbuild/modules/pkgconfig.py

@@ -23,13 +23,15 @@ class PkgConfigModule:
 
     def generate_pkgconfig_file(self, state, libraries, subdirs, name, description, version, filebase,
                                 pub_reqs, priv_reqs, priv_libs):
+        coredata = state.environment.get_coredata()
         outdir = state.environment.scratch_dir
         fname = os.path.join(outdir, filebase + '.pc')
-        ofile = open(fname, 'w')
-        coredata = state.environment.get_coredata()
+        with open(fname, 'w') as ofile:
             ofile.write('prefix=%s\n' % coredata.get_builtin_option('prefix'))
-        ofile.write('libdir=${prefix}/%s\n' % coredata.get_builtin_option('libdir'))
-        ofile.write('includedir=${prefix}/%s\n\n' % coredata.get_builtin_option('includedir'))
+            ofile.write('libdir=${prefix}/%s\n' %
+                        coredata.get_builtin_option('libdir'))
+            ofile.write('includedir=${prefix}/%s\n\n' %
+                        coredata.get_builtin_option('includedir'))
             ofile.write('Name: %s\n' % name)
             if len(description) > 0:
                 ofile.write('Description: %s\n' % description)
@@ -38,9 +40,11 @@ class PkgConfigModule:
             if len(pub_reqs) > 0:
                 ofile.write('Requires: {}\n'.format(' '.join(pub_reqs)))
             if len(priv_reqs) > 0:
-            ofile.write('Requires.private: {}\n'.format(' '.join(priv_reqs)))
+                ofile.write(
+                    'Requires.private: {}\n'.format(' '.join(priv_reqs)))
             if len(priv_libs) > 0:
-            ofile.write('Libraries.private: {}\n'.format(' '.join(priv_libs)))
+                ofile.write(
+                    'Libraries.private: {}\n'.format(' '.join(priv_libs)))
             ofile.write('Libs: -L${libdir} ')
             for l in libraries:
                 if l.custom_install_dir:

mesonbuild/modules/rpm.py

@@ -80,7 +80,9 @@ class RPMModule:
                 files.add('%%{_mandir}/man%u/%s.*' % (int(man_file.split('.')[-1]), man_file))
         if len(files_devel) > 0:
             devel_subpkg = True
-        fn = open('%s.spec' % os.path.join(state.environment.get_build_dir(), proj), 'w+')
+        filename = os.path.join(state.environment.get_build_dir(),
+                                '%s.spec' % proj)
+        with open(filename, 'w+') as fn:
             fn.write('Name: %s\n' % proj)
             fn.write('Version: # FIXME\n')
             fn.write('Release: 1%{?dist}\n')
@@ -95,12 +97,15 @@ class RPMModule:
                 fn.write('BuildRequires: pkgconfig(%s)\n' % dep)
             for lib in state.environment.coredata.ext_libs.values():
                 fn.write('BuildRequires: %s # FIXME\n' % lib.fullpath)
-            mlog.log('Warning, replace', mlog.bold(lib.fullpath), 'with real package.',
-                     'You can use following command to find package which contains this lib:',
+                mlog.log('Warning, replace', mlog.bold(lib.fullpath),
+                         'with real package.',
+                         'You can use following command to find package which '
+                         'contains this lib:',
                          mlog.bold('dnf provides %s' % lib.fullpath))
             for prog in state.environment.coredata.ext_progs.values():
                 if not prog.found():
-                fn.write('BuildRequires: /usr/bin/%s # FIXME\n' % prog.get_name())
+                    fn.write('BuildRequires: /usr/bin/%s # FIXME\n' %
+                             prog.get_name())
                 else:
                     fn.write('BuildRequires: %s\n' % ' '.join(prog.fullpath))
             fn.write('BuildRequires: meson\n')
@@ -152,10 +157,10 @@ class RPMModule:
                 fn.write('%postun -p /sbin/ldconfig\n')
             fn.write('\n')
             fn.write('%changelog\n')
-        fn.write('* %s meson <meson@example.com> - \n' % datetime.date.today().strftime('%a %b %d %Y'))
+            fn.write('* %s meson <meson@example.com> - \n' %
+                     datetime.date.today().strftime('%a %b %d %Y'))
             fn.write('- \n')
             fn.write('\n')
-        fn.close()
         mlog.log('RPM spec template written to %s.spec.\n' % proj)
 
 def initialize():

mesonbuild/optinterpreter.py

@@ -78,7 +78,8 @@ class OptionInterpreter:
 
     def process(self, option_file):
         try:
-            ast = mparser.Parser(open(option_file, 'r', encoding='utf8').read()).parse()
+            with open(option_file, 'r', encoding='utf8') as f:
+                ast = mparser.Parser(f.read()).parse()
         except mesonlib.MesonException as me:
             me.file = option_file
             raise me

mesonbuild/scripts/meson_benchmark.py

@@ -52,14 +52,15 @@ 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.
+    with open(jsonlogfilename, 'w') as jsonlogfile:
         for i, test in enumerate(tests):
             runs = []
             durations = []

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__':

mesonbuild/scripts/meson_install.py

@@ -38,7 +38,7 @@ def do_copy(from_file, to_file):
     append_to_log(to_file)
 
 def do_install(datafilename):
-    ifile = open(datafilename, 'rb')
+    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:]]

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
@@ -222,6 +220,11 @@ def run_tests(datafilename):
     executor = conc.ThreadPoolExecutor(max_workers=num_workers)
     futures = []
     filtered_tests = filter_tests(options.suite, tests)
+
+    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
@@ -235,10 +238,12 @@ def run_tests(datafilename):
                 drain_futures(futures)
                 futures = []
                 res = run_single_test(wrap, test)
-            print_stats(numlen, filtered_tests, visible_name, res, i, logfile, jsonlogfile)
+                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))
+                futures.append((f, numlen, filtered_tests, visible_name, i,
+                                logfile, jsonlogfile))
         drain_futures(futures)
     return logfilename
 

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

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)

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]

mesonbuild/wrap/wrap.py

@@ -58,7 +58,7 @@ def open_wrapdburl(urlstring):
 class PackageDefinition:
     def __init__(self, fname):
         self.values = {}
-        ifile = open(fname)
+        with open(fname) as ifile:
             first = ifile.readline().strip()
 
             if first == '[wrap-file]':
@@ -177,7 +177,8 @@ class Resolver:
         expected = p.get('source_hash')
         if dhash != expected:
             raise RuntimeError('Incorrect hash for source %s:\n %s expected\n %s actual.' % (packagename, expected, dhash))
-        open(ofname, 'wb').write(srcdata)
+        with open(ofname, 'wb') as f:
+            f.write(srcdata)
         if p.has_patch():
             purl = p.get('patch_url')
             mlog.log('Downloading patch from', mlog.bold(purl))
@@ -186,7 +187,9 @@ class Resolver:
             expected = p.get('patch_hash')
             if phash != expected:
                 raise RuntimeError('Incorrect hash for patch %s:\n %s expected\n %s actual' % (packagename, expected, phash))
-            open(os.path.join(self.cachedir, p.get('patch_filename')), 'wb').write(pdata)
+            filename = os.path.join(self.cachedir, p.get('patch_filename'))
+            with open(filename, 'wb') as f:
+                f.write(pdata)
         else:
             mlog.log('Package does not require patch.')
 

mesonbuild/wrap/wraptool.py

@@ -92,7 +92,8 @@ def install(name):
     (branch, revision) = get_latest_version(name)
     u = open_wrapdburl(API_ROOT + 'projects/%s/%s/%s/get_wrap' % (name, branch, revision))
     data = u.read()
-    open(wrapfile, 'wb').write(data)
+    with open(wrapfile, 'wb') as f:
+        f.write(data)
     print('Installed', name, 'branch', branch, 'revision', revision)
 
 def get_current_version(wrapfile):
@@ -129,7 +130,8 @@ def update(name):
         os.unlink(os.path.join('subprojects/packagecache', patch_file))
     except FileNotFoundError:
         pass
-    open(wrapfile, 'wb').write(data)
+    with open(wrapfile, 'wb') as f:
+        f.write(data)
     print('Updated', name, 'to branch', new_branch, 'revision', new_revision)
 
 def info(name):