Merge branch 'jennis/pylint_no_else_raise' into 'master'

Address pylint 2.3.x's no-else-raise warning

See merge request BuildStream/buildstream!1586

14 files changed, 63 insertions, 60 deletions

diff --git a/src/buildstream/_cas/cascache.py b/src/buildstream/_cas/cascache.py
index b4bba2b6d..fa6705b70 100644
--- a/src/buildstream/_cas/cascache.py
+++ b/src/buildstream/_cas/cascache.py
@@ -341,8 +341,7 @@ class CASCache():
         except grpc.RpcError as e:
             if e.code() != grpc.StatusCode.NOT_FOUND:
                 raise CASCacheError("Failed to pull ref {}: {}".format(ref, e)) from e
-            else:
-                return False
+            return False
         except BlobNotFound:
             return False
 
@@ -481,7 +480,7 @@ class CASCache():
             blob_response = response.responses[0]
             if blob_response.status.code == code_pb2.RESOURCE_EXHAUSTED:
                 raise CASCacheError("Cache too full", reason="cache-too-full")
-            elif blob_response.status.code != code_pb2.OK:
+            if blob_response.status.code != code_pb2.OK:
                 raise CASCacheError("Failed to capture blob {}: {}".format(path, blob_response.status.code))
             digest.CopyFrom(blob_response.digest)
 
diff --git a/src/buildstream/_cas/casremote.py b/src/buildstream/_cas/casremote.py
index 05b57d3d4..ba0477550 100644
--- a/src/buildstream/_cas/casremote.py
+++ b/src/buildstream/_cas/casremote.py
@@ -291,8 +291,8 @@ class _CASBatchRead():
                 if missing_blobs is None:
                     raise BlobNotFound(response.digest.hash, "Failed to download blob {}: {}".format(
                         response.digest.hash, response.status.code))
-                else:
-                    missing_blobs.append(response.digest)
+
+                missing_blobs.append(response.digest)
 
             if response.status.code != code_pb2.OK:
                 raise CASRemoteError("Failed to download blob {}: {}".format(
diff --git a/src/buildstream/_cas/casserver.py b/src/buildstream/_cas/casserver.py
index 5a4c2b7ac..ca7a21955 100644
--- a/src/buildstream/_cas/casserver.py
+++ b/src/buildstream/_cas/casserver.py
@@ -291,10 +291,10 @@ class _ContentAddressableStorageServicer(remote_execution_pb2_grpc.ContentAddres
             except OSError as e:
                 if e.errno != errno.ENOENT:
                     raise
-                else:
-                    d = response.missing_blob_digests.add()
-                    d.hash = digest.hash
-                    d.size_bytes = digest.size_bytes
+
+                d = response.missing_blob_digests.add()
+                d.hash = digest.hash
+                d.size_bytes = digest.size_bytes
 
         return response
 
diff --git a/src/buildstream/_frontend/app.py b/src/buildstream/_frontend/app.py
index 236e8f80b..f9729a7ce 100644
--- a/src/buildstream/_frontend/app.py
+++ b/src/buildstream/_frontend/app.py
@@ -915,7 +915,8 @@ def _prefix_choice_value_proc(choices):
 
         if not remaining_candidate:
             raise UsageError("Expected one of {}, got {}".format(choices, user_input))
-        elif len(remaining_candidate) == 1:
+
+        if len(remaining_candidate) == 1:
             return remaining_candidate[0]
         else:
             raise UsageError("Ambiguous input. '{}' can refer to one of {}".format(user_input, remaining_candidate))
diff --git a/src/buildstream/_frontend/cli.py b/src/buildstream/_frontend/cli.py
index 3fad1664d..d45e3a578 100644
--- a/src/buildstream/_frontend/cli.py
+++ b/src/buildstream/_frontend/cli.py
@@ -629,9 +629,8 @@ def shell(app, element, sysroot, mount, isolate, build_, cli_buildtree, pull_, c
                 if cli_buildtree == "always":
                     # Exit early if it won't be possible to even fetch a buildtree with always option
                     raise AppError("Artifact was created without buildtree, unable to launch shell with it")
-                else:
-                    click.echo("WARNING: Artifact created without buildtree, shell will be loaded without it",
-                               err=True)
+                click.echo("WARNING: Artifact created without buildtree, shell will be loaded without it",
+                           err=True)
         else:
             # If the value has defaulted to ask and in non interactive mode, don't consider the buildtree, this
             # being the default behaviour of the command
diff --git a/src/buildstream/_includes.py b/src/buildstream/_includes.py
index 0ba40e63d..c04601b91 100644
--- a/src/buildstream/_includes.py
+++ b/src/buildstream/_includes.py
@@ -58,12 +58,13 @@ class Includes:
                         message = "{}: Include block references a file that could not be found: '{}'.".format(
                             include_provenance, include)
                         raise LoadError(message, LoadErrorReason.MISSING_FILE) from e
-                    elif e.reason == LoadErrorReason.LOADING_DIRECTORY:
+                    if e.reason == LoadErrorReason.LOADING_DIRECTORY:
                         message = "{}: Include block references a directory instead of a file: '{}'.".format(
                             include_provenance, include)
                         raise LoadError(message, LoadErrorReason.LOADING_DIRECTORY) from e
-                    else:
-                        raise
+
+                    # Otherwise, we don't know the reason, so just raise
+                    raise
 
                 if file_path in included:
                     include_provenance = includes_node.get_provenance()
diff --git a/src/buildstream/_loader/loader.py b/src/buildstream/_loader/loader.py
index b2dc7c1c3..5599c8b71 100644
--- a/src/buildstream/_loader/loader.py
+++ b/src/buildstream/_loader/loader.py
@@ -250,7 +250,7 @@ class Loader():
 
                 raise LoadError(message, LoadErrorReason.MISSING_FILE, detail=detail) from e
 
-            elif e.reason == LoadErrorReason.LOADING_DIRECTORY:
+            if e.reason == LoadErrorReason.LOADING_DIRECTORY:
                 # If a <directory>.bst file exists in the element path,
                 # let's suggest this as a plausible alternative.
                 message = str(e)
@@ -261,8 +261,10 @@ class Loader():
                     element_name = filename + '.bst'
                     detail = "Did you mean '{}'?\n".format(element_name)
                 raise LoadError(message, LoadErrorReason.LOADING_DIRECTORY, detail=detail) from e
-            else:
-                raise
+
+            # Otherwise, we don't know the reason, so just raise
+            raise
+
         kind = node.get_str(Symbol.KIND)
         if kind == "junction":
             self._first_pass_options.process_node(node)
@@ -561,11 +563,11 @@ class Loader():
             if level == 0:
                 # junction element not found in this or ancestor projects
                 raise
-            else:
-                # mark junction as not available to allow detection of
-                # conflicting junctions in subprojects
-                self._loaders[filename] = None
-                return None
+
+            # mark junction as not available to allow detection of
+            # conflicting junctions in subprojects
+            self._loaders[filename] = None
+            return None
 
         # meta junction element
         # XXX: This is a likely point for progress reporting to end up
@@ -636,8 +638,9 @@ class Loader():
                 if element.path:
                     message += " Was expecting it at path '{}' in the junction's source.".format(element.path)
                 raise LoadError(message=message, reason=LoadErrorReason.INVALID_JUNCTION) from e
-            else:
-                raise
+
+            # Otherwise, we don't know the reason, so just raise
+            raise
 
         loader = project.loader
         self._loaders[filename] = loader
diff --git a/src/buildstream/_project.py b/src/buildstream/_project.py
index 6cbf3d889..ceba4c44b 100644
--- a/src/buildstream/_project.py
+++ b/src/buildstream/_project.py
@@ -581,8 +581,9 @@ class Project():
             # Raise a more specific error here
             if e.reason == LoadErrorReason.MISSING_FILE:
                 raise LoadError(str(e), LoadErrorReason.MISSING_PROJECT_CONF) from e
-            else:
-                raise
+
+            # Otherwise re-raise the original exception
+            raise
 
         pre_config_node = self._default_config_node.clone()
         self._project_conf._composite(pre_config_node)
diff --git a/src/buildstream/_stream.py b/src/buildstream/_stream.py
index b3e0a6183..2e43bb1a2 100644
--- a/src/buildstream/_stream.py
+++ b/src/buildstream/_stream.py
@@ -217,8 +217,8 @@ class Stream():
                     message = "Buildtree is not cached locally or in available remotes"
                     if usebuildtree == "always":
                         raise StreamError(message)
-                    else:
-                        self._message(MessageType.INFO, message + ", shell will be loaded without it")
+
+                    self._message(MessageType.INFO, message + ", shell will be loaded without it")
             else:
                 buildtree = True
 
@@ -481,9 +481,9 @@ class Stream():
                 msg = "{} is not cached".format(element.name)
                 if self._context.sched_error_action != _SchedulerErrorAction.CONTINUE:
                     raise StreamError("Push failed: " + msg)
-                else:
-                    self._message(MessageType.WARN, msg)
-                    uncached_elements.append(element)
+
+                self._message(MessageType.WARN, msg)
+                uncached_elements.append(element)
 
         if cached_elements:
             self._scheduler.clear_queues()
@@ -1356,7 +1356,7 @@ class Stream():
 
         if status == SchedStatus.ERROR:
             raise StreamError()
-        elif status == SchedStatus.TERMINATED:
+        if status == SchedStatus.TERMINATED:
             raise StreamError(terminated=True)
 
     # _fetch()
diff --git a/src/buildstream/sandbox/_sandboxbuildbox.py b/src/buildstream/sandbox/_sandboxbuildbox.py
index 99c7322a3..4258ee26d 100644
--- a/src/buildstream/sandbox/_sandboxbuildbox.py
+++ b/src/buildstream/sandbox/_sandboxbuildbox.py
@@ -38,8 +38,8 @@ class SandboxBuildBox(Sandbox):
     def __init__(self, context, project, directory, **kwargs):
         if kwargs.get('allow_real_directory'):
             raise SandboxError("BuildBox does not support real directories")
-        else:
-            kwargs['allow_real_directory'] = False
+
+        kwargs['allow_real_directory'] = False
         super().__init__(context, project, directory, **kwargs)
 
     @classmethod
@@ -61,7 +61,7 @@ class SandboxBuildBox(Sandbox):
         # Check host os and architecture match
         if config.build_os != platform.get_host_os():
             raise SandboxError("Configured and host OS don't match.")
-        elif config.build_arch != platform.get_host_arch():
+        if config.build_arch != platform.get_host_arch():
             raise SandboxError("Configured and host architecture don't match.")
 
         return True
diff --git a/src/buildstream/sandbox/_sandboxbwrap.py b/src/buildstream/sandbox/_sandboxbwrap.py
index d8541354c..bd60eafc1 100644
--- a/src/buildstream/sandbox/_sandboxbwrap.py
+++ b/src/buildstream/sandbox/_sandboxbwrap.py
@@ -129,9 +129,8 @@ class SandboxBwrap(Sandbox):
         host_arch = local_platform.get_host_arch()
         if config.build_os != host_os:
             raise SandboxError("Configured and host OS don't match.")
-        elif config.build_arch != host_arch:
-            if not local_platform.can_crossbuild(config):
-                raise SandboxError("Configured architecture and host architecture don't match.")
+        if config.build_arch != host_arch and not local_platform.can_crossbuild(config):
+            raise SandboxError("Configured architecture and host architecture don't match.")
 
         return True
 
diff --git a/src/buildstream/sandbox/_sandboxchroot.py b/src/buildstream/sandbox/_sandboxchroot.py
index eb8f53308..8d4c54058 100644
--- a/src/buildstream/sandbox/_sandboxchroot.py
+++ b/src/buildstream/sandbox/_sandboxchroot.py
@@ -70,7 +70,7 @@ class SandboxChroot(Sandbox):
         # Check host os and architecture match
         if config.build_os != host_os:
             raise PlatformError("Configured and host OS don't match.")
-        elif config.build_arch != host_arch:
+        if config.build_arch != host_arch:
             raise PlatformError("Configured and host architecture don't match.")
 
         return True
@@ -218,8 +218,9 @@ class SandboxChroot(Sandbox):
                 raise SandboxError('Could not chroot into {} or chdir into {}. '
                                    'Ensure you are root and that the relevant directory exists.'
                                    .format(rootfs, cwd)) from e
-            else:
-                raise SandboxError('Could not run command {}: {}'.format(command, e)) from e
+
+            # Otherwise, raise a more general error
+            raise SandboxError('Could not run command {}: {}'.format(command, e)) from e
 
         return code
 
@@ -252,8 +253,8 @@ class SandboxChroot(Sandbox):
                     if err.errno == 1:
                         raise SandboxError("Permission denied while creating device node: {}.".format(err) +
                                            "BuildStream reqiures root permissions for these setttings.")
-                    else:
-                        raise
+
+                    raise
 
         yield
 
diff --git a/src/buildstream/sandbox/_sandboxremote.py b/src/buildstream/sandbox/_sandboxremote.py
index e9e145d1f..cf034dbf9 100644
--- a/src/buildstream/sandbox/_sandboxremote.py
+++ b/src/buildstream/sandbox/_sandboxremote.py
@@ -210,14 +210,14 @@ class SandboxRemote(Sandbox):
                     raise SandboxError("Failed contacting remote execution server at {}."
                                        .format(self.exec_url))
 
-                elif status_code in (grpc.StatusCode.INVALID_ARGUMENT,
-                                     grpc.StatusCode.FAILED_PRECONDITION,
-                                     grpc.StatusCode.RESOURCE_EXHAUSTED,
-                                     grpc.StatusCode.INTERNAL,
-                                     grpc.StatusCode.DEADLINE_EXCEEDED):
+                if status_code in (grpc.StatusCode.INVALID_ARGUMENT,
+                                   grpc.StatusCode.FAILED_PRECONDITION,
+                                   grpc.StatusCode.RESOURCE_EXHAUSTED,
+                                   grpc.StatusCode.INTERNAL,
+                                   grpc.StatusCode.DEADLINE_EXCEEDED):
                     raise SandboxError("{} ({}).".format(e.details(), status_code.name))
 
-                elif running_operation and status_code == grpc.StatusCode.UNIMPLEMENTED:
+                if running_operation and status_code == grpc.StatusCode.UNIMPLEMENTED:
                     raise SandboxError("Failed trying to recover from connection loss: "
                                        "server does not support operation status polling recovery.")
 
@@ -267,10 +267,10 @@ class SandboxRemote(Sandbox):
         #
         if output_files:
             raise SandboxError("Output files were returned when we didn't request any.")
-        elif not output_directories:
+        if not output_directories:
             error_text = "No output directory was returned from the build server."
             raise SandboxError(error_text)
-        elif len(output_directories) > 1:
+        if len(output_directories) > 1:
             error_text = "More than one output directory was returned from the build server: {}."
             raise SandboxError(error_text.format(output_directories))
 
@@ -458,8 +458,7 @@ class SandboxRemote(Sandbox):
                 if e.code() != grpc.StatusCode.NOT_FOUND:
                     raise SandboxError("Failed to query action cache: {} ({})"
                                        .format(e.code(), e.details()))
-                else:
-                    return None
+                return None
             else:
                 self.info("Action result found in action cache")
                 return result
@@ -499,8 +498,8 @@ class SandboxRemote(Sandbox):
             # system failed at processing the execution request.
             if execution_response.status.message:
                 raise SandboxError(execution_response.status.message)
-            else:
-                raise SandboxError("Remote server failed at executing the build request.")
+            # Otherwise, report the failure in a more general manner
+            raise SandboxError("Remote server failed at executing the build request.")
 
         return execution_response.result
 
diff --git a/src/buildstream/utils.py b/src/buildstream/utils.py
index 32d23d27c..de7c14b70 100644
--- a/src/buildstream/utils.py
+++ b/src/buildstream/utils.py
@@ -1406,9 +1406,9 @@ def _get_compression(tar):
         if suffix == '.tar':
             raise UtilError("Expected compression with unknown file extension ('{}'), "
                             "supported extensions are ('.tar'), ('.gz'), ('.xz'), ('.bz2')".format(ext))
-        else:
-            # Assume just an unconventional name was provided, default to uncompressed
-            return ''
+
+        # Assume just an unconventional name was provided, default to uncompressed
+        return ''
 
 
 # _is_single_threaded()