[lttng-dev] lttng-ust cross compile broken for demo-tracef

[Thibault, Daniel]

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> Date: Mon, 7 Apr 2014 13:43:21 +0200
> From: Jan Glauber <jan.glauber at gmail.com>
>
> I get a compile error with current git head of lttng-ust if I cross-compile (bitbake):
>
> | make[4]: Entering directory `/home/jang/temp/p4/JGlauber_hal_share/poky/build/tmp/work/armv7ahf-vfp-neon-elina-linux-gnueabi/lttng-ust-2.4-r0/git/doc/examples/demo-tracef'
> | arm-linux-gnueabihf-gcc  -march=armv7-a     -mthumb-interwork -mfloat-abi=hard -mfpu=neon -mtune=cortex-a15 \
> |                --sysroot=/home/jang/temp/p4/JGlauber_hal_share/poky/build/tmp/sysroots/omap5 -L/home/jang/te \
> |                -o demo-tracef demo-tracef.o -ldl -llttng-ust
> | demo-tracef.o: file not recognized: File format not recognized
> | collect2: error: ld returned 1 exit status
> | make[4]: *** [demo-tracef] Error 1
>
> Looks like the demo-tracef Makefile sets CC hard to gcc. But if I fix this I get more
> errors which I don't undertand. Am I the only one running into this?
>
> Harman Becker Automotive GmbH
> System Profiling & Optimizing Team

   The " demo-tracef.o: file not recognized: File format not recognized" is a dead giveaway that you are in a mixed-bitness context.  The linker is in 64-bit mode while demo-tracef.o was compiled in 32-bit mode, or vice-versa.  Or it could be byte sex.  Clearly, the linker call is not using the same config that was used to create demo-tracef.o.  (My apologies if this seems obvious to you; I'm not familiar with bitbake)

Daniel U. Thibault
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