misc: updated shabang for python script

The default python on MacOS doesn’t have an alias to python2.
The official python version supported in gem5 is Python2.7.

This patch updates the shabang according to the version required in gem5.

Change-Id: I9533c0f7858b5b3cab0ef101be1ee5cd718105b0
Reviewed-on: https://gem5-review.googlesource.com/c/15375
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>

misc: Update #!env calls for python to explicit version

In some newer Linux distributions, env python default to Python 3.0. This
patch explicitly uses "python2" instead of just "python" for all scripts
that use #!

Reported-by: Sanchayan Maity <maitysanchayan@gmail.com>
Signed-off-by: Jason Lowe-Power <jason@lowepower.com>

style: Add options to select checkers and apply fixes

Add an option, --checker/-c, to style.py that selects individual style
checkers to apply. When this option isn't specified, the script
defaults to all available style checkers. The option may be specified
multiple times to run multiple style checkers.

The option, --fix/-f, can be specified to automatically fix style
violations.

Change-Id: Id7597fba6b65cecfa17a88b1c87c8a4c8315af59
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Andreas Hansson <andreas.hansson@arm.com>

style: Add a style checker that doesn't depend on Mercurial

The current style checker script, hgstyle.py, assumes that it is being
run from Mercurial. This means that it depends on the Mercurial Python
libraries, which aren't necessarily present if using git. This
changeset adds a new style checker script, style.py, that has
been designed to be run from the command line.

The script has support for detecting which revision control system is
used and is able to query both git and Mercurial for changes. This
enables the script to operate on modified regions and/or all of the
modified files in the repository.

Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Curtis Dunham <curtis.dunham@arm.com>
Reviewed-by: Steve Reinhardt <steve.reinhardt@amd.com>

scons, style: Rename style.py to hgstyle.py

The Mercurial style checker extensions are currently stored in
style.py. This is not ideal since they won't work with other version
control systems. This changeset renames style.py to hgstyle.py and
adds upgrade code to scons that automatically updates the hooks in
hgrc.

Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-by: Curtis Dunham <curtis.dunham@arm.com>
Reviewed-by: Nathanael Premillieu <nathananel.premillieu@arm.com>
Reviewed-by: Steve Reinhardt <steve.reinhardt@amd.com>

style: Remove unsupported style.py commands

Remove the unsupported style.py subcommands (fixwhite, chkwhite),
which leaves the chkformat command as the only remaining
command. Since the script now only supports one command, remove the
sub-command support altogether.

Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-by: Curtis Dunham <curtis.dunham@arm.com>
Reviewed-by: Nathanael Premillieu <nathananel.premillieu@arm.com>

style: Strip newline when checking lines

The style checker incorrectly includes newlines when checking lines of
code, which effectively decreases the column limit by 1. This
changeset strips the newline character from before calling line
checkers.

Change-Id: I0a8c7707ece57d782d11cc86db4b8064db291ce0
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>

util: added line length and boolean comparison style checkers

Added checkers for line length and boolean comparisons
(== true/== false) to the style script.

util: clean up and extend style checker

Added a new Verifier object to check for and fix spacing
between if/while/for and following paren.

Restructured Verifier class to make it easier to add
new subclasses, particularly by using a global list of
verifiers to auto-generate command line options and
simplify the invocation loop.

style: Fix broken m5format command

The m5format command didn't actually work due to parameter handling
issues and missing language detection. This changeset fixes those
issues and cleans up some of the code to shared between the style
checker and the format checker.

style: Fix incorrect style checker option name

The style used to support the option -w to automatically fix white
space issues. However, this option was actually wired up to fix all
styles issues the checker encountered. This changeset cleans up the
code that handles automatic fixing and adds an option to fix all
issues, and separate options for white spaces and include ordering.

style: Update the style checker to handle new include order

As of August 2014, the gem5 style guide mandates that a source file's
primary header is included first in that source file. This helps to
ensure that the header file does not depend on include file ordering
and avoids surprises down the road when someone tries to reuse code.

In the new order, include files are grouped into the following blocks:
* Primary header file (e.g., foo.hh for foo.cc)
* Python headers
* C system/stdlib includes
* C++ stdlib includes
* Include files in the gem5 source tree

Just like before, include files within a block are required to be
sorted in alphabetical order.

This changeset updates the style checker to enforce the new order.

style: Add support for a style ignore list and ignore ext/

There are some directories within the repository where we don't want
to enforce our coding style. Specifically, we don't want the style
hooks to warn whenever we update external code in the ext/ directory.

style: Fixup strange semantics in hg m5style

The 'hg m5style' command had some rather strange semantics. When
called without arguments, it applied the style checker to all added
files and modified regions of modified files. However, when providing
a list of files, it used that list as an ignore list instead of
specifically checking those files.

This patch makes the m5style command behave more like other Mercurial
commands where the arguments are used to specify which files to work
on instead of which files to ignore.

Util: Do not style check symlinks

The style checker used to traverse symlinks if they pointed to files, which can
result in style checker failure if the pointed-to file doesn't exist. This
style check is actually unnecessary, since symlinks either point to other files
that are already style checked, or files outside gem5, which shouldn't be
checked. Skip symlinks.

util: Fix issues with style checker.

Style: Make style.py's invalid warning print which file caused the infraction.

style.py: don't die on empty files

style: Make the style hook work in directories other than the root.

style: fix all_regions code and remove bogus region type

style: remove extra debugging print

style: add sort_includes to the style hook

style: move style verifiers into classes

style: add a user interface wrapper class
makes things work both with mercurial and stand alone with stdio

Style checker: Fix a couple bugs in style.py.

style: prevent the style hook from aborting uncleanly because of an exception

style: clean up style hook code a bit

I've renamed the check_whitespace operation to check_style. You're going to
need to change your .hg/hgrc file. While you're at it, add a pre-qrefresh
hook please.

style: make style hook work with pre-qrefresh and update to use new code
clean up the code a little bit while we're at it.

I recommend that everyone adds the pre-qrefresh hook below since it
will make qref run the style hook and not just commit/qpush

[extensions]
style = <m5 path>/util/style.py

[hooks]
pretxncommit.style = python:style.check_whitespace
pre-qrefresh.style = python:style.check_whitespace

style_hook: Fix the style hook
Re-enable it and update it for more modern versions of mercurial.

Functionality migrated to sequencer.

[mq]: first_patch

style: fix style hook for some newer versions of mercurial.

Fix style hook for Mercurial >= 1.1

Remove the pointless, repository destroying assertion and just have the script check every line in the file if it cannot get context information.

Add hg commands for style check so you can check at times other than commit

Fix minor bug in util/style.py

style: fix style hook when run from a repo subdir.
Before this fix, the style hook would blow up when you did a qrefresh to add
a new file, but executed the qrefresh from a repository sub directory.

style: Don't try to fix files that should be ignored.
The style hook was ignoring new files, but processing all modified
files.

Merge with head. style.py was also missing an argument in one call to modified_lines.

Work around a mercurial bug in bdiff.blocks

style: fix stupid bugs

style: Check/Fix whitespace on SCons files

Allow the fixwhite stuff to work when committing from a subdir

do proper style checks for merged files

fix the style fixing thing

Add code to turn the style stuff into a mercurial hook.
Nag the user during compile if they have an hg cloned copy of M5, have
mercurial installed, but don't have the style hook enabled.