[clang] [sanitizer] [clang] Introduce fsanitize-bounds-strict-flex-arrays (PR #126163)

[Florian Mayer via cfe-commits]

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@@ -1192,13 +1193,40 @@ llvm::Value *CodeGenFunction::EmitLoadOfCountedByField(
   return nullptr;
 }
 
+LangOptions::StrictFlexArraysLevelKind
+CodeGenFunction::effectiveArrayBoundsFlexArraysLevel() {
+  using StrictFlexArraysLevelKind = LangOptions::StrictFlexArraysLevelKind;
+  using ArrayBoundsStrictFlexArraysLevelKind =
+      LangOptions::ArrayBoundsStrictFlexArraysLevelKind;
+  StrictFlexArraysLevelKind StrictFlexArraysLevel;
+  switch (getLangOpts().getArrayBoundsStrictFlexArraysLevel()) {
+  case ArrayBoundsStrictFlexArraysLevelKind::Default:
+    StrictFlexArraysLevel = StrictFlexArraysLevelKind::Default;
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fmayer wrote:

because now we only store 3 bits for for this, using -1 would be a waste

https://github.com/llvm/llvm-project/pull/126163