786148 - s/IPC/ipc/

Status: RESOLVED FIXED

(Core :: IPC, defect)

Description

[Rafael Ávila de Espíndola (:espindola) (not reading bugmail)]

Attachment: s/IPC/ipc/

Believe it or not this is not a nop: on OS X with a case insensitive filesystem (the default) this reduces the symbol table size by one.

The problem is that when processing

#include "IPC/IPCMessageUtils.h

we end up in

#include "ShadowLayers.h"

which in the final XUL translates into the symbol (run nm -a to see it):

 - 00 0000   SOL ../../../../gfx/layers/IPC/ShadowLayers.h

now when some file in gfx/layers/ipc does

#include "ShadowLayres.h"

the file found is the local one with the lowercase directory name and we end up with

 - 00 0000   SOL ../../../../gfx/layers/ipc/ShadowLayers.h

Cutting one symbol is probably insignificant, but making our builds more reproducible is not. I found this while trying to figure out why a build done on try gets better scores on dromaeo than one done locally on the same OS, with same xcode and clang. This is probably not it, but any differences in the binaries helps hide the problem.

Comment 1

[(not currently active) Ted Mielczarek]

Comment on attachment 655863 [details] [diff] [review]
s/IPC/ipc/

Review of attachment 655863 [details] [diff] [review]:
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Crazy!

Comment 2

[Rafael Ávila de Espíndola (:espindola) (not reading bugmail)]

https://hg.mozilla.org/integration/mozilla-inbound/rev/468a7e985d82

Comment 3

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/468a7e985d82