[llvm-branch-commits] [clang] [HLSL] Implement explicit layout for default constant buffer ($Globals) (PR #128991)

[Damyan Pepper via llvm-branch-commits]

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@@ -179,21 +179,45 @@ createBufferHandleType(const HLSLBufferDecl *BufDecl) {
   return cast<HLSLAttributedResourceType>(QT.getTypePtr());
 }
 
+// Iterates over all declarations in the HLSL buffer and based on the
+// packoffset or register(c#) annotations it fills outs the Layout
+// vector with the user-specified layout offsets.
+// The buffer offsets can be specified 2 ways:
+// 1. declarations in cbuffer {} block can have a packoffset annotation
+//    (translates to HLSLPackOffsetAttr)
+// 2. default constant buffer declarations at global scope can have
+//    register(c#) annotations (translates to HLSLResourceBindingAttr with
+//    RegisterType::C)
+// It is not quaranteed that all declarations in a buffer have an annotation.
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damyanp wrote:

```suggestion
// It is not guaranteed that all declarations in a buffer have an annotation.
```

https://github.com/llvm/llvm-project/pull/128991