662964 - Silence the clang warnings issued because of alignment requirements increase when compiling jscntxt.h

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[(no longer active)]

These warnings drive me nuts.  We get thousands of them when compiling jscntxt.h.

jsapi.cpp
In file included from /Users/ehsanakhgari/moz/tmp/js/src/jsapi.cpp:61:
In file included from /Users/ehsanakhgari/moz/tmp/js/src/jsclone.h:43:
/Users/ehsanakhgari/moz/tmp/js/src/jscntxt.h:2279:12: warning: cast from 'uint8 *' (aka 'unsigned char *') to 'JSContext *' increases required alignment from 1 to 8
      [-Wcast-align]
    return (JSContext *) ((uint8 *) link - offsetof(JSContext, link));
           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Comment 1

[(no longer active)]

Attachment: Patch (v1)

Comment 2

[Jeff Walden [:Waldo]]

Comment on attachment 538142 [details] [diff] [review]
Patch (v1)

>-    return (JSContext *) ((uint8 *) link - offsetof(JSContext, link));
>+    return (JSContext *) (void *) ((uint8 *) link - offsetof(JSContext, link));

Another place where uintptr_t seems better than an extra cast:

>+    return reinterpret_cast<JSContext *>(uintptr_t(link) - offsetof(JSContext, link));

Comment 3

[(no longer active)]

http://hg.mozilla.org/tracemonkey/rev/3167cf2cde1c

Comment 4

[Chris Leary [:cdleary] (not checking bugmail)]

cdleary-bot mozilla-central merge info:
http://hg.mozilla.org/mozilla-central/rev/3167cf2cde1c