>> Here's the non-lto build:
>> arm-none-eabi-gcc -O0 -g -Wl,-y,malloc,-v,-t -c -o main.o main.c
>> arm-none-eabi-gcc -O0 -g -Wl,-y,malloc,-v,-t -c -o t1.o t1.c
>> arm-none-eabi-gcc -O -g -Wl,-y,malloc,-v,-t main.o t1.o -o main
>> collect2 version 11.1.0
>> /usr/libexec/gcc/arm-none-eabi/ld -plugin
>> /usr/libexec/gcc/arm-none-eabi/11.1.0/liblto_plugin.so
>> -plugin-opt=/usr/libexec/gcc/arm-none-eabi/11.1.0/lto-wrapper
>> -plugin-opt=-fresolution=/tmp/ccyt1CxF.res -plugin-opt=-pass-through=-lgcc
>> -plugin-opt=-pass-through=-lg -plugin-opt=-pass-through=-lc
>> --sysroot=/usr/arm-none-eabi -X -o main
>> /usr/lib/gcc/arm-none-eabi/11.1.0/crti.o
>> /usr/lib/gcc/arm-none-eabi/11.1.0/crtbegin.o
>> /usr/lib/gcc/arm-none-eabi/11.1.0/../../../../arm-none-eabi/lib/crt0.o
>> -L/usr/lib/gcc/arm-none-eabi/11.1.0
>> -L/usr/lib/gcc/arm-none-eabi/11.1.0/../../../../arm-none-eabi/lib
>> -L/usr/arm-none-eabi/lib -L/usr/arm-none-eabi/usr/lib -y malloc -v -t main.o
>> t1.o --start-group -lgcc -lg -lc --end-group
>> /usr/lib/gcc/arm-none-eabi/11.1.0/crtend.o
>> /usr/lib/gcc/arm-none-eabi/11.1.0/crtn.o
>> GNU ld (Gentoo 2.36.1 p3) 2.36.1
>> /usr/lib/gcc/arm-none-eabi/11.1.0/crti.o
>> /usr/lib/gcc/arm-none-eabi/11.1.0/crtbegin.o
>> /usr/lib/gcc/arm-none-eabi/11.1.0/../../../../arm-none-eabi/lib/crt0.o
>> main.o
>> t1.o
>> /usr/libexec/gcc/arm-none-eabi/ld: t1.o: reference to malloc
>> /usr/lib/gcc/arm-none-eabi/11.1.0/libgcc.a
>> /usr/lib/gcc/arm-none-eabi/11.1.0/../../../../arm-none-eabi/lib/libg.a
>> /usr/libexec/gcc/arm-none-eabi/ld: lib_a-malloc.o (symbol from plugin): definition of malloc
>
> So this line ("symbol from plugin")
>
>> /usr/lib/gcc/arm-none-eabi/11.1.0/../../../../arm-none-eabi/lib/libc.a
>> /usr/lib/gcc/arm-none-eabi/11.1.0/libgcc.a
>> /usr/lib/gcc/arm-none-eabi/11.1.0/../../../../arm-none-eabi/lib/libg.a
>> /usr/lib/gcc/arm-none-eabi/11.1.0/../../../../arm-none-eabi/lib/libc.a
>> /usr/lib/gcc/arm-none-eabi/11.1.0/crtend.o
>> /usr/lib/gcc/arm-none-eabi/11.1.0/crtn.o
>> /tmp/ccHV3ALY.ltrans0.ltrans.o
>> /usr/libexec/gcc/arm-none-eabi/ld: /tmp/ccHV3ALY.ltrans0.ltrans.o: definition of malloc
>
> and this line (synthesized ltrans unit) indicate that your libc.a has LTO
> bytecode.
>
>
> How did that happen, did you build Newlib with -flto?
>
>
> Alexander
>
Most likely, I'm leveraging Gentoo's crossdev functionality to build
GCC/binutils/newlib, and I do have a global -flto flag enabled on my system,
which I selectively disable for specific packages whenever I find problems. Can
newlib not be built with -flto? Does it need something like -ffat-lto-objects?
And why does it matter if it was built with lto (or is this behavior just due
to the special treatment of libc's in general when linking/building)?
Thanks,
Gabe
