515224 - casting from int8* to structures might cause problems on some platforms (i.e. ARM)

Status: RESOLVED INCOMPLETE

(Core :: JavaScript Engine, defect)

Description

[Andreas Gal :gal]

../jsfun.cpp:426: warning: cast from 'uint8*' to 'JSObjectArray*' increases required alignment of target type
../jsfun.cpp:430: warning: cast from 'uint8*' to 'JSObjectArray*' increases required alignment of target type
../jsfun.cpp:433: warning: cast from 'uint8*' to 'JSTryNoteArray*' increases required alignment of target type
../jsfun.cpp:445: warning: cast from 'uint8*' to 'JSObjectArray*' increases required alignment of target type
../jsfun.cpp:445: warning: cast from 'uint8*' to 'JSObjectArray*' increases required alignment of target type
../jsfun.cpp:446: warning: cast from 'uint8*' to 'JSObjectArray*' increases required alignment of target type
../jsfun.cpp:449: warning: cast from 'uint8*' to 'JSObjectArray*' increases required alignment of target type
../jsfun.cpp:449: warning: cast from 'uint8*' to 'JSObjectArray*' increases required alignment of target type
../jsfun.cpp:450: warning: cast from 'uint8*' to 'JSObjectArray*' increases required alignment of target type
../jsfun.cpp:453: warning: cast from 'uint8*' to 'JSTryNoteArray*' increases required alignment of target type
../jsfun.cpp:453: warning: cast from 'uint8*' to 'JSTryNoteArray*' increases required alignment of target type
../jsfun.cpp:454: warning: cast from 'uint8*' to 'JSTryNoteArray*' increases required alignment of target type
../jsfun.cpp:458: warning: cast from 'uint8*' to 'JSUpvarArray*' increases required alignment of target type
../jsfun.cpp:459: warning: cast from 'uint8*' to 'JSUpvarArray*' increases required alignment of target type
../jsfun.cpp:459: warning: cast from 'uint8*' to 'JSUpvarArray*' increases required alignment of target type

We should probably stop doing this kind of pointer math to be on the safe side.

Comment 1

[Brendan Eich [:brendan]]

The warnings are spurious. We know what we are doing here (mostly, or this time for sure! see bug 514645 which I recently fixed).

How do we suppress these warnings?

/be

Comment 2

[Jim Blandy :jimb]

I don't see these with G++ 4.3.3.  What compiler?

Comment 3

[Andreas Gal :gal]

ubuntu@armbuild1:~$ /opt/cs2007q3/bin/gcc -v
Using built-in specs.
Target: arm-linux-gnueabi
Configured with: ./configure --build=arm-linux-gnueabi --target=arm-linux-gnueabi --host=arm-linux-gnueabi --prefix=/opt/cs2007q3 --with-pkgversion=CS 2007q3-53 --disable-nls --disable-threads --disable-libmudflap --disable-libssp --disable-libgomp --disable-libstdcxx-pch --with-gnu-as --with-gnu-ld --enable-languages=c,c++ --disable-shared --disable-decimal-float --disable-bootstrap
Thread model: single
gcc version 4.2.1 (CS 2007q3-53)

Comment 4

[Lars T Hansen [:lth]]

The target types (JSUpvarArray, etc) are gone and the casts in question are no longer in jsfun.cpp.