[clang] [llvm] [DebugInfo] Emit DW_AT_const_value for constexpr array static members (PR #182442)

[Shivam Kunwar via cfe-commits]

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@@ -2097,6 +2092,53 @@ CGDebugInfo::CreateRecordStaticField(const VarDecl *Var, llvm::DIType *RecordTy,
         C = llvm::ConstantInt::get(CGM.getLLVMContext(), Value->getInt());
       if (Value->isFloat())
         C = llvm::ConstantFP::get(CGM.getLLVMContext(), Value->getFloat());
+      if (Value->isArray()) {
+        // Handle constexpr array constants for debug info
+        // We handle arrays of integer types (char, short, int, long),
+        // which covers the most common and useful cases.
+        if (const auto *ArrayTy =
+                CGM.getContext().getAsArrayType(Var->getType())) {
+          QualType ElemQTy = ArrayTy->getElementType();
+          if (ElemQTy->isIntegerType()) {
+            unsigned ElemBitWidth = CGM.getContext().getTypeSize(ElemQTy);
+            unsigned NumElts = Value->getArraySize();
+            unsigned NumInits = Value->getArrayInitializedElts();
+            SmallVector<uint64_t, 64> Vals;
+            Vals.reserve(NumElts);
+            bool Success = true;
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phyBrackets wrote:

Addressed this differently following @dzhidzhoev  suggestion, with preallocating the vector with the filler value and then overwriting with initialized elements. This avoids the Success bool pattern entirely

https://github.com/llvm/llvm-project/pull/182442