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

[Vitaly Buka 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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vitalybuka wrote:

However, I can't reproduce with MachOYAML::Section!

Because it IO.mapRequired("Size" before optional, so if size is missing, Section.content will not be set, and nothing to match.

so the following is a fix (bad) as well :)

```
 static void fillMapping(IO &IO, ELFYAML::Fill &Fill) {
+  IO.mapRequired("Size", Fill.Size);
   IO.mapOptional("Name", Fill.Name, StringRef());
   IO.mapOptional("Pattern", Fill.Pattern);
   IO.mapOptional("Offset", Fill.Offset);
-  IO.mapRequired("Size", Fill.Size);
 }
```


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