Mercurial > hg
view doc/style.css @ 29642:8960fcb76ca4 stable
demandimport: avoid infinite recursion at actual module importing (issue5304)
Before this patch, importing C module on Windows environment causes
infinite recursion call, if py2exe is used with -b2 option.
At importing C module "a.b", extra hooking by zipextimporter of py2exe
causes:
0. assumption before accessing "b" of "a":
- built-in module object is created for "a",
(= "a" is actually imported)
- _demandmod is created for "a.b" as a proxy object, and
(= "a.b" is not yet imported)
- an attribute "b" of "a" is initialized by the latter
1. invocation of __import__ via _hgextimport() in _demandmod._load()
for "a.b" implies _demandimport() for "a.b"
This is unintentional, because _demandmod might be returned by
_hgextimport() instead of built-in module object.
2. _demandimport() at (1) is invoked with not context of "a", but
context of zipextimporter
Just after invocation of _hgextimport() in _demandimport(), an
attribute "b" of the built-in module object for "a" is still
bound to the proxy object for "a.b", because context of "a" isn't
updated by actual importing "a.b". even though the built-in
module object for "a.b" already appears in sys.modules.
Therefore, chainmodules() returns _demandmod for "a.b", which is
gotten from the attribute "b" of "a".
3. processfromitem() on "a.b" causes _demandmod._load() for "a.b"
again
_demandimport() takes context of "a" in this case.
Therefore, attributes below are bound to built-in module object
for "a.b", as expected:
- "b" of built-in module object for "a"
- _module of _demandmod for "a.b"
4. but _demandimport() invoked at (1) returns _demandmod object
because _demandimport() just returns the object returned by
chainmodules() at (3) above.
5. then, _demandmod._load() causes infinite recursion call
_demandimport() returns _demandmod for "a.b", and it is "self" at
_demandmod._load().
To avoid infinite recursion at actual module importing, this patch
uses self._module, if _hgextimport() returns _demandmod itself. If
_demandmod._module isn't yet bound at this point, execution should be
aborted, because actual importing failed.
In this patch, _demandmod._module is examined not on _demandimport()
side, but on _demandmod._load() side, because:
- the former has some exit points
- only the latter uses _hgextimport(), except for _demandimport()
BTW, this issue occurs only in the code path for non .py/.pyc files in
zipextimporter (strictly speaking, in _memimporter) of py2exe.
Even if zipextimporter is enabled, .py/.pyc files are handled by
zipimporter, and it doesn't imply unintentional _demandimport() at
invocation of __import__ via _hgextimport().
author | FUJIWARA Katsunori <foozy@lares.dti.ne.jp> |
---|---|
date | Sun, 31 Jul 2016 05:39:59 +0900 |
parents | 4b0fc75f9403 |
children |
line wrap: on
line source
/* * Styles for man pages, which match with https://mercurial-scm.org/ * * Color scheme & layout are borrowed from * https://mercurial-scm.org/css/styles.css * * Some styles are from html4css1.css from Docutils, which is in the * public domain. */ body { margin: 0; padding: 0; font-family: sans-serif; } .document { position: relative; /* be a top of absolute positioning */ margin: 1.5em 1.8em; padding: 0; line-height: 1.3; } /* layout: toc to right */ #contents { position: absolute; right: 0; top: 0; width: 26%; } /* layout: others to left */ h1.title, h2.subtitle, .section { width: 72%; } .section .section { width: auto; } table.docinfo { max-width: 72%; } /* headings */ h1, h2, .topic-title, .admonition-title { font-family: "MgOpen Cosmetica", "Lucida Sans Unicode", sans-serif; font-weight: normal; } h1, h2, .topic-title, .admonition-title { margin: 1em 0 0.5em; } h1.title { font-size: 300%; } h2.subtitle, h1 { font-size: 200%; } h2, .topic-title, .admonition-title { font-size: 140%; } /* subtitle starts with lowercase in man pages, but not in HTML */ h2.subtitle:first-letter { text-transform: uppercase; } /* override first/last margin */ .first, h1.title, h2.subtitle { margin-top: 0 !important; } .last, .with-subtitle { margin-bottom: 0 !important; } blockquote, pre, dd .option-list, .field-list { margin: 0.2em 0 1em 2em; } kbd, tt, pre { font-family: monospace; } dt { font-weight: bold; } dd { margin-bottom: 0.5em; } th, td { padding: 0.1em 0.2em; border: 0 none; } th { font-weight: bold; text-align: left; } a:link, a:visited { text-decoration: underline; } a:hover, a:focus { text-decoration: none; } a:link { color: #00b5f1; } a:visited { color: #5c9caf; } a:link.toc-backref, a:visited.toc-backref { text-decoration: none; color: inherit; /* NOTE: `inherit' is not supported by IE6 */ } div.admonition, div.attention, div.caution, div.danger, div.error, div.hint, div.important, div.note, div.tip, div.warning { border-top: 1px #ccc solid; border-bottom: 1px #ccc solid; padding: 0.3em 1em; margin: 1em; } div.note { border-color: #fcc200; } /* * The following styles are from Docutils. * Please refine if necessary. */ table.borderless td, table.borderless th { /* Override padding for "table.docutils td" with "! important". The right padding separates the table cells. */ padding: 0 0.5em 0 0 ! important; } .hidden { display: none; } blockquote.epigraph { margin: 2em 5em; } div.abstract { margin: 2em 5em; } div.dedication { margin: 2em 5em; text-align: center; font-style: italic; } div.figure { margin-left: 2em; margin-right: 2em; } div.footer, div.header { clear: both; font-size: smaller; } div.line-block { display: block; margin-top: 1em; margin-bottom: 1em; } div.line-block div.line-block { margin-top: 0; margin-bottom: 0; margin-left: 1.5em; } div.sidebar { margin: 0 0 0.5em 1em; border: medium outset; padding: 1em; background-color: #ffffee; width: 40%; float: right; clear: right; } div.sidebar p.rubric { font-family: sans-serif; font-size: medium; } div.system-messages { margin: 5em; } div.system-messages h1 { color: red; } div.system-message { border: medium outset; padding: 1em; } div.system-message p.system-message-title { color: red; font-weight: bold; } h1.section-subtitle, h2.section-subtitle, h3.section-subtitle, h4.section-subtitle, h5.section-subtitle, h6.section-subtitle { margin-top: 0.4em; } hr.docutils { width: 75%; } img.align-left { clear: left; } img.align-right { clear: right; } ol.simple, ul.simple { margin-bottom: 1em; } ol.arabic { list-style: decimal; } ol.loweralpha { list-style: lower-alpha; } ol.upperalpha { list-style: upper-alpha; } ol.lowerroman { list-style: lower-roman; } ol.upperroman { list-style: upper-roman; } p.attribution { text-align: right; margin-left: 50%; } p.caption { font-style: italic; } p.credits { font-style: italic; font-size: smaller; } p.label { white-space: nowrap; } p.rubric { font-weight: bold; font-size: larger; color: maroon; text-align: center; } pre.address { margin-bottom: 0; margin-top: 0; font-family: serif; font-size: 100%; } pre.literal-block, pre.doctest-block { margin-left: 2em; margin-right: 2em; } span.classifier { font-family: sans-serif; font-style: oblique; } span.classifier-delimiter { font-family: sans-serif; font-weight: bold; } span.interpreted { font-family: sans-serif; } span.option { white-space: nowrap; } span.pre { white-space: pre; } span.problematic { color: red; } span.section-subtitle { /* font-size relative to parent (h1..h6 element) */ font-size: 80%; } table.citation { border-left: solid 1px gray; margin-left: 1px; } table.footnote { border-left: solid 1px black; margin-left: 1px; } h1 tt.docutils, h2 tt.docutils, h3 tt.docutils, h4 tt.docutils, h5 tt.docutils, h6 tt.docutils { font-size: 100%; } ul.auto-toc { list-style-type: none; } div.contents.local { -moz-column-width: 10em; -moz-column-gap: 1em; -webkit-column-width: 10em; -webkit-column-gap: 1em; }