I use arm-none-eabi-gcc 7.2.1 in my project, when I want to use -flto option to optimize bin size, error shows:
../../../tools/gcc/linux/gcc-arm-none-eabi/bin/arm-none-eabi-ar: creating /proj/lib_m.a../../../tools/gcc/linux/gcc-arm-none-eabi/bin/arm-none-eabi-ar: /proj/src/n1.o: plugin needed to handle lto object../../../tools/gcc/linux/gcc-arm-none-eabi/bin/arm-none-eabi-ar: /projsrc/nb_data.o: plugin needed to handle lto object
what's wrong with my code?
Thank you for your replay.
Please could you provide the complete command-line you use? Also, could you please let us know where did you get arm-none-eabi-gcc 7.2.1 from? It would help us triage the issue if you could give us a small test case that demonstrates the symptom you're observing.
I've managed to reproduce your issue. Here are the steps I tried:
$ arm-none-eabi-gcc -c -O2 -flto foo.c -o foo.o
$ arm-none-eabi-gcc -c -O2 -flto bar.c -o bar.o
$ arm-none-eabi-ar -vr libfoobar.a foo.o bar.o
arm-none-eabi-ar: foo.o: plugin needed to handle lto object
Try giving a --plugin option to your ar command-line:
$ arm-none-eabi-ar -vr --plugin .../path/to/liblto_plugin.so libfoobar.a foo.o bar.o
liblto_plugin.so usually resides in .../path/to/gcc/install/bin/libexec/gcc/7.2.1/liblto_plugin.so
sorry for late, I have resolved the problem, in build I add -ffat-lto-objects, and in link I add --use-linker-plugin, so the "plugin needed to handle lto object" message appear no more!