What does the "-DPACKAGE" means?

[Dengke Du]

Hi all

What does the "-DPACKAGE" means?
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$(OUTPUT)test-libbfd.bin:
     $(BUILD) -DPACKAGE='"perf"' -lbfd -lz -liberty -ldl
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In this link:
https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git/tree/tools/build/feature/Makefile?id=fb982666e380c1632a74495b68b3c33a66e76430#n189