rust: switch hg-core and hg-cpython to rust 2018 edition
Many interesting changes have happened in Rust since the Oxidation Plan was
introduced, like the 2018 edition and procedural macros:
- Opting in to the 2018 edition is a clear benefit in terms of future
proofing, new (nice to have) syntactical sugar notwithstanding. It
also has a new non-lexical, non-AST based borrow checker that has
fewer bugs(!) and allows us to write correct code that in some cases
would have been rejected by the old one.
- Procedural macros allow us to use the PyO3 crate which maintainers have
expressed the clear goal of compiling on stable, which would help in
code maintainability compared to rust-cpython.
In this patch are the following changes:
- Removing most `extern crate` uses
- Updating `use` clauses (`crate` keyword, nested `use`)
- Removing `mod.rs` in favor of an aptly named module file
Like discussed in the mailing list (
https://www.mercurial-scm.org/pipermail/mercurial-devel/2019-July/132316.html
), until Rust integration in Mercurial is considered to be out of the
experimental phase, the maximum version of Rust allowed is whatever the latest
version Debian packages.
Differential Revision: https://phab.mercurial-scm.org/D6597
#!/usr/bin/env python
"""usage: %s DOC ...
where DOC is the name of a document
"""
from __future__ import absolute_import
import os
import sys
import textwrap
try:
import msvcrt
msvcrt.setmode(sys.stdout.fileno(), os.O_BINARY)
msvcrt.setmode(sys.stderr.fileno(), os.O_BINARY)
except ImportError:
pass
# This script is executed during installs and may not have C extensions
# available. Relax C module requirements.
os.environ[r'HGMODULEPOLICY'] = r'allow'
# import from the live mercurial repo
sys.path.insert(0, r"..")
from mercurial import demandimport; demandimport.enable()
# Load util so that the locale path is set by i18n.setdatapath() before
# calling _().
from mercurial import util
util.datapath
from mercurial import (
commands,
encoding,
extensions,
help,
minirst,
pycompat,
ui as uimod,
)
from mercurial.i18n import (
gettext,
_,
)
table = commands.table
globalopts = commands.globalopts
helptable = help.helptable
loaddoc = help.loaddoc
def get_desc(docstr):
if not docstr:
return b"", b""
# sanitize
docstr = docstr.strip(b"\n")
docstr = docstr.rstrip()
shortdesc = docstr.splitlines()[0].strip()
i = docstr.find(b"\n")
if i != -1:
desc = docstr[i + 2:]
else:
desc = shortdesc
desc = textwrap.dedent(desc.decode('latin1')).encode('latin1')
return (shortdesc, desc)
def get_opts(opts):
for opt in opts:
if len(opt) == 5:
shortopt, longopt, default, desc, optlabel = opt
else:
shortopt, longopt, default, desc = opt
optlabel = _(b"VALUE")
allopts = []
if shortopt:
allopts.append(b"-%s" % shortopt)
if longopt:
allopts.append(b"--%s" % longopt)
if isinstance(default, list):
allopts[-1] += b" <%s[+]>" % optlabel
elif (default is not None) and not isinstance(default, bool):
allopts[-1] += b" <%s>" % optlabel
if b'\n' in desc:
# only remove line breaks and indentation
desc = b' '.join(l.lstrip() for l in desc.split(b'\n'))
desc += default and _(b" (default: %s)") % bytes(default) or b""
yield (b", ".join(allopts), desc)
def get_cmd(cmd, cmdtable):
d = {}
attr = cmdtable[cmd]
cmds = cmd.lstrip(b"^").split(b"|")
d[b'cmd'] = cmds[0]
d[b'aliases'] = cmd.split(b"|")[1:]
d[b'desc'] = get_desc(gettext(pycompat.getdoc(attr[0])))
d[b'opts'] = list(get_opts(attr[1]))
s = b'hg ' + cmds[0]
if len(attr) > 2:
if not attr[2].startswith(b'hg'):
s += b' ' + attr[2]
else:
s = attr[2]
d[b'synopsis'] = s.strip()
return d
def showdoc(ui):
# print options
ui.write(minirst.section(_(b"Options")))
multioccur = False
for optstr, desc in get_opts(globalopts):
ui.write(b"%s\n %s\n\n" % (optstr, desc))
if optstr.endswith(b"[+]>"):
multioccur = True
if multioccur:
ui.write(_(b"\n[+] marked option can be specified multiple times\n"))
ui.write(b"\n")
# print cmds
ui.write(minirst.section(_(b"Commands")))
commandprinter(ui, table, minirst.subsection, minirst.subsubsection)
# print help topics
# The config help topic is included in the hgrc.5 man page.
helpprinter(ui, helptable, minirst.section, exclude=[b'config'])
ui.write(minirst.section(_(b"Extensions")))
ui.write(_(b"This section contains help for extensions that are "
b"distributed together with Mercurial. Help for other "
b"extensions is available in the help system."))
ui.write((b"\n\n"
b".. contents::\n"
b" :class: htmlonly\n"
b" :local:\n"
b" :depth: 1\n\n"))
for extensionname in sorted(allextensionnames()):
mod = extensions.load(ui, extensionname, None)
ui.write(minirst.subsection(extensionname))
ui.write(b"%s\n\n" % gettext(pycompat.getdoc(mod)))
cmdtable = getattr(mod, 'cmdtable', None)
if cmdtable:
ui.write(minirst.subsubsection(_(b'Commands')))
commandprinter(ui, cmdtable, minirst.subsubsubsection,
minirst.subsubsubsubsection)
def showtopic(ui, topic):
extrahelptable = [
([b"common"], b'', loaddoc(b'common'), help.TOPIC_CATEGORY_MISC),
([b"hg.1"], b'', loaddoc(b'hg.1'), help.TOPIC_CATEGORY_CONFIG),
([b"hg-ssh.8"], b'', loaddoc(b'hg-ssh.8'), help.TOPIC_CATEGORY_CONFIG),
([b"hgignore.5"], b'', loaddoc(b'hgignore.5'),
help.TOPIC_CATEGORY_CONFIG),
([b"hgrc.5"], b'', loaddoc(b'hgrc.5'), help.TOPIC_CATEGORY_CONFIG),
([b"hgignore.5.gendoc"], b'', loaddoc(b'hgignore'),
help.TOPIC_CATEGORY_CONFIG),
([b"hgrc.5.gendoc"], b'', loaddoc(b'config'),
help.TOPIC_CATEGORY_CONFIG),
]
helpprinter(ui, helptable + extrahelptable, None, include=[topic])
def helpprinter(ui, helptable, sectionfunc, include=[], exclude=[]):
for h in helptable:
names, sec, doc = h[0:3]
if exclude and names[0] in exclude:
continue
if include and names[0] not in include:
continue
for name in names:
ui.write(b".. _%s:\n" % name)
ui.write(b"\n")
if sectionfunc:
ui.write(sectionfunc(sec))
if callable(doc):
doc = doc(ui)
ui.write(doc)
ui.write(b"\n")
def commandprinter(ui, cmdtable, sectionfunc, subsectionfunc):
"""Render restructuredtext describing a list of commands and their
documentations, grouped by command category.
Args:
ui: UI object to write the output to
cmdtable: a dict that maps a string of the command name plus its aliases
(separated with pipes) to a 3-tuple of (the command's function, a list
of its option descriptions, and a string summarizing available
options). Example, with aliases added for demonstration purposes:
'phase|alias1|alias2': (
<function phase at 0x7f0816b05e60>,
[ ('p', 'public', False, 'set changeset phase to public'),
...,
('r', 'rev', [], 'target revision', 'REV')],
'[-p|-d|-s] [-f] [-r] [REV...]'
)
sectionfunc: minirst function to format command category headers
subsectionfunc: minirst function to format command headers
"""
h = {}
for c, attr in cmdtable.items():
f = c.split(b"|")[0]
f = f.lstrip(b"^")
h[f] = c
cmds = h.keys()
def helpcategory(cmd):
"""Given a canonical command name from `cmds` (above), retrieve its
help category. If helpcategory is None, default to CATEGORY_NONE.
"""
fullname = h[cmd]
details = cmdtable[fullname]
helpcategory = details[0].helpcategory
return helpcategory or help.registrar.command.CATEGORY_NONE
cmdsbycategory = {category: [] for category in help.CATEGORY_ORDER}
for cmd in cmds:
# If a command category wasn't registered, the command won't get
# rendered below, so we raise an AssertionError.
if helpcategory(cmd) not in cmdsbycategory:
raise AssertionError(
"The following command did not register its (category) in "
"help.CATEGORY_ORDER: %s (%s)" % (cmd, helpcategory(cmd)))
cmdsbycategory[helpcategory(cmd)].append(cmd)
# Print the help for each command. We present the commands grouped by
# category, and we use help.CATEGORY_ORDER as a guide for a helpful order
# in which to present the categories.
for category in help.CATEGORY_ORDER:
categorycmds = cmdsbycategory[category]
if not categorycmds:
# Skip empty categories
continue
# Print a section header for the category.
# For now, the category header is at the same level as the headers for
# the commands in the category; this is fixed in the next commit.
ui.write(sectionfunc(help.CATEGORY_NAMES[category]))
# Print each command in the category
for f in sorted(categorycmds):
if f.startswith(b"debug"):
continue
d = get_cmd(h[f], cmdtable)
ui.write(subsectionfunc(d[b'cmd']))
# short description
ui.write(d[b'desc'][0])
# synopsis
ui.write(b"::\n\n")
synopsislines = d[b'synopsis'].splitlines()
for line in synopsislines:
# some commands (such as rebase) have a multi-line
# synopsis
ui.write(b" %s\n" % line)
ui.write(b'\n')
# description
ui.write(b"%s\n\n" % d[b'desc'][1])
# options
opt_output = list(d[b'opts'])
if opt_output:
opts_len = max([len(line[0]) for line in opt_output])
ui.write(_(b"Options:\n\n"))
multioccur = False
for optstr, desc in opt_output:
if desc:
s = b"%-*s %s" % (opts_len, optstr, desc)
else:
s = optstr
ui.write(b"%s\n" % s)
if optstr.endswith(b"[+]>"):
multioccur = True
if multioccur:
ui.write(_(b"\n[+] marked option can be specified"
b" multiple times\n"))
ui.write(b"\n")
# aliases
if d[b'aliases']:
ui.write(_(b" aliases: %s\n\n") % b" ".join(d[b'aliases']))
def allextensionnames():
return set(extensions.enabled().keys()) | set(extensions.disabled().keys())
if __name__ == "__main__":
doc = b'hg.1.gendoc'
if len(sys.argv) > 1:
doc = encoding.strtolocal(sys.argv[1])
ui = uimod.ui.load()
if doc == b'hg.1.gendoc':
showdoc(ui)
else:
showtopic(ui, encoding.strtolocal(sys.argv[1]))