Friday, 25 September 2009

Code: iPhone linker error (__restore_vfp_d8_d15_regs)

In my iPhone development I encountered link errors along the lines of:
"___restore_vfp_d8_d15_regs", referenced from:
-[Blah blah:] in blah.o
"___save_vfp_d8_d15_regs", referenced from:
-[Blah blah:] in blah.o

Google had a little to say about it. Unfortunately, it all appeared wrong.

The issue was a subtle one. The application's "Library search paths" (LIBRARY_SEARCH_PATHS) variable has some historic cruft in it which caused the linker to pull in and old incompatible version of libstdc++, with a consequence of much hilarity and hair-pulling.

When I removed "$(SDKROOT)/usr/lib/gcc/arm-apple-darwin9/4.0.1" from the list (not sure where this had come from) the application magically linked one more, and kittens and puppies danced with my iPhone once more.


Jamie said...

Thanks for posting this - saved me a lot of frustration!

springrider said...
This comment has been removed by the author.
springrider said...

well, another reason will cause this problem, if your target device is iPad/iPhone compatiable, the "archeitecures" in project setting might be "Optimized armv6 armv7", took me hours to figure out, I changed it to "standard armv6", works for iPhone. reference:

abernathie said...

Serious props for this tip. Many more kittens and puppies are dancing!

Andy said...

Thank you! saved me hours of agony as well. I was adding a cpp library to an iOS project in which the original dev used the Three20 library-- which was explicitly linking to several old versions of libstdc++

Miri said...

Thank you! I would never guess this is the reason. You save a lot of my hours too.