[lld] ELF: Introduce --shuffle-padding flag. (PR #117653)

[Peter Smith via llvm-commits]

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@@ -2753,6 +2753,21 @@ RelroPaddingSection::RelroPaddingSection(Ctx &ctx)
     : SyntheticSection(ctx, ".relro_padding", SHT_NOBITS, SHF_ALLOC | SHF_WRITE,
                        1) {}
 
+ShufflePaddingSection::ShufflePaddingSection(Ctx &ctx, uint64_t size,
+                                             OutputSection *parent)
+    : SyntheticSection(ctx, ".shuffle_padding", SHF_ALLOC, SHT_PROGBITS, 1),
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smithp35 wrote:

Do these flags behave themselves in the case of .bss and .data?

I'd expect if there is at least one other .data section the combined OutputSection flags would be SHF_WRITE. Could be interesting if there's no existing .data, although I expect there won't be any of these section inserted in that case. 

Would the SHT_PROGBITs padding sections in .bss result in the combined .bss Output Section being output as SHT_PROGBITS? This might not be ideal if benchmarking program startup, although shouldn't make a difference to the program runtime.

https://github.com/llvm/llvm-project/pull/117653