[clang] [Clang] Improve EmitClangAttrSpellingListIndex (PR #114899)

[Nikita Popov via cfe-commits]

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@@ -153,12 +155,37 @@ std::string AttributeCommonInfo::getNormalizedFullName() const {
       normalizeName(getAttrName(), getScopeName(), getSyntax()));
 }
 
+// Sorted list of attribute scope names
+static constexpr std::pair<StringRef, AttributeCommonInfo::Scope> ScopeList[] =
+    {{"", AttributeCommonInfo::Scope::NONE},
+     {"clang", AttributeCommonInfo::Scope::CLANG},
+     {"gnu", AttributeCommonInfo::Scope::GNU},
+     {"gsl", AttributeCommonInfo::Scope::GSL},
+     {"hlsl", AttributeCommonInfo::Scope::HLSL},
+     {"msvc", AttributeCommonInfo::Scope::MSVC},
+     {"omp", AttributeCommonInfo::Scope::OMP},
+     {"riscv", AttributeCommonInfo::Scope::RISCV}};
+
+AttributeCommonInfo::Scope
+getScopeFromNormalizedScopeName(StringRef ScopeName) {
+  auto It = std::lower_bound(
+      std::begin(ScopeList), std::end(ScopeList), ScopeName,
+      [](const std::pair<StringRef, AttributeCommonInfo::Scope> &Element,
+         StringRef Value) { return Element.first < Value; });
+  assert(It != std::end(ScopeList) && It->first == ScopeName);
+
+  return It->second;
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nikic wrote:

This looks like exactly what `StringSwitch` is for...

https://github.com/llvm/llvm-project/pull/114899