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GNU as started to emit warnings for changed sh_type or sh_flags in 2000.
GNU as>=2.35 will emit errors for most type/flags change, and error for entsize change.
Some cases () remain warnings for legacy reasons:
.section .init_array,"ax", at progbits .section .init_array,"ax", at init_array # And some obscure sh_flags changes (OS/Processor specific flags)
The rationale of a diagnostic (warning or error) is that sh_type,
sh_flags or sh_entsize changes usually indicate user errors.
We just try to be more rigid and emit errors for all sh_type/sh_flags/sh_entsize change.
A possible improvement in the future is to reuse
llvm-readobj/ELFDumper.cpp:getSectionTypeString so that we can name the
type in the diagnostics.