undefined reference to 'alloca'

[K-Y-L]

Hi, I am having the same problem as https://github.com/H2CO3/libsprec/issues/3. (I am using the rapsberry pi)

When I try to compile 'simple.c' with the following command "gcc -o simple simple.c -lsprec -lpthread" the following came up: /usr/lib/gcc/arm-linux-gnueabihf/4.8/../../../libsprec.so: undefined reference to 'alloca' collect2: error: ld returned 1 exit status

I tried to delete the library and build it again, but it doesn't work for me and I am quite stuck here. Is there a way I can fix this problem?

Thank you

[H2CO3]

Hi,

No, in fact, you're not having the same problem. My library uses libpthread (the POSIX thread library), and that issue is about libpthread. However, my library does not use alloca(). I don't really understand why your compiler is trying to insert calls to this function, but it's not my code. What version of GCC are you using?

[K-Y-L]

the version of my gcc compiler is 4.8.2 And I build libsprec(and libjsonz) by following the steps from: http://raspberrypi.stackexchange.com/questions/10384/speech-processing-on-the-raspberry-pi

[K-Y-L]

Is it something to do with the way I build libsprec and libjsonz or there is a problem with the libpthred? I can't really find any solutions to this..

[H2CO3]

Honestly, I don't know. The code doesn't use alloca() at all; it's possible that GCC inserts calls to this function for stack-allocation of some variable, but in this case, the function should be in the libc implementation you're using. Did you make sure you have a proper cross-build of the library (i. e. you have compiled and linked a libsprec.dylib for the Raspberry Pi's architecture)? Otherwise, your build seems fine…

[K-Y-L]

In fact, when I was trying to build the libsprec using "make", the following came up:

[LHIOUI]

Hi You can fix this by defining alloca in wav.c file like this

#define alloca(x)  __builtin_alloca(x)