[PATCH] D69607: Add a feature to explain why some file gets included to the linker's output

[Fangrui Song via Phabricator via llvm-commits]

MaskRay added inline comments.


================
Comment at: lld/ELF/Explain.cpp:101
+  enqueueSpecial("(--entry option)", config->entry);
+  enqueueSpecial("(--init option)", config->init);
+  enqueueSpecial("(--fini option)", config->fini);
----------------
--init and --fini are used in --gc-sections but they do not fetch lazy definitions. I do not know why GNU ld behaves this way.


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Comment at: lld/ELF/Explain.cpp:157
+
+  if (!seen.insert(sym.file).second)
+    return;
----------------
We can make edges a superset of specialEdges, then we can just delete `seen` and use `edges.try_emplace(...)` here.


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Comment at: lld/ELF/Explain.cpp:167
+  auto *sym = dyn_cast_or_null<Defined>(symtab->find(symName));
+  if (!sym || sym->isWeak())
+    return;
----------------
pcc wrote:
> I don't think the `isWeak` part here is correct.
`-u`/`-e` can fetch a weak lazy definition. This may cause a bogus `file unreachable` error.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D69607/new/

https://reviews.llvm.org/D69607