[SOLVED] Getting GCC to compile without inserting call to memcpy

Getting GCC to compile without inserting call to memcpy

I'm currently using GCC 4.5.3, compiled for PowerPC 440, and am compiling some code that doesn't require libc. I don't have any direct calls to memcpy(), but the compiler seems to be inserting one during the build.

There are linker options like -nostdlib, -nostartfiles, -nodefaultlibs but I'm unable to use them as I'm not doing the linking phase. I'm only compiling. With something like this:

$ powerpc-440-eabi-gcc -O2 -g -c -o output.o input.c

If I check the output.o with nm, I see a reference to memcpy:

$ powerpc-440-eabi-nm output.o | grep memcpy
     U memcpy
$

The GCC man page makes it clear how to remove calls to memcpy and other libc calls with the linker, but I don't want the compiler to insert them in the first place, as I'm using a completely different linker (not GNU's ld, and it doesn't know about libc).

Thanks for any help you can provide.

Solution

You need to disable a that optimization with -fno-builtin. I had this problem once when trying to compile memcpy for a C library. It called itself. Oops!