[llvm-branch-commits] [YAML] Don't validate `Fill::Size` after error (PR #123280)

[James Henderson via llvm-branch-commits]

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@@ -1750,7 +1750,9 @@ void MappingTraits<std::unique_ptr<ELFYAML::Chunk>>::mapping(
 std::string MappingTraits<std::unique_ptr<ELFYAML::Chunk>>::validate(
     IO &io, std::unique_ptr<ELFYAML::Chunk> &C) {
   if (const auto *F = dyn_cast<ELFYAML::Fill>(C.get())) {
-    if (F->Pattern && F->Pattern->binary_size() != 0 && !F->Size)
+    // Can't check the `Size`, as it's required and may be left uninitialized by
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jh7370 wrote:

At a guess, based on the comment, it's when the `Size` field in the YAML is missing for a `Fill`?

I'm beginning to think that `mapRequired` should zero-initialise the value that is being mapped, even on failure. I suspect there are many more cases along these lines too.

https://github.com/llvm/llvm-project/pull/123280