[clang] Fix incorrect array initialization with string literal (fixes #112189) (PR #156846)

[via cfe-commits]

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@@ -168,16 +168,95 @@ bool Sema::IsStringInit(Expr *Init, const ArrayType *AT) {
   return ::IsStringInit(Init, AT, Context) == SIF_None;
 }
 
+static StringLiteral *CloneStringLiteral(const StringLiteral *SL,
+                                         ASTContext &C) {
+  SourceLocation *SLocs = new (C) SourceLocation[SL->getNumConcatenated()];
+  std::copy(SL->tokloc_begin(), SL->tokloc_end(), SLocs);
+  return StringLiteral::Create(
+      C, SL->getBytes(), SL->getKind(), SL->isPascal(), SL->getType(),
+      ArrayRef<SourceLocation>(SLocs, SL->getNumConcatenated()));
+}
+
+// Exactly follow `IgnoreParensSingleStep` (`AST/IgnoreExpr.h`)
+// We only clone those subexpressions which `IgnoreParensSingleStep` drills down
+// to.
+static Expr *CloneDrilled(Expr *E, ASTContext &C) {
+  if (auto *SL = dyn_cast<StringLiteral>(E)) {
+    return CloneStringLiteral(SL, C);
+  }
+
+  if (auto *PE = dyn_cast<ParenExpr>(E)) {
+    return new (C) ParenExpr(PE->getBeginLoc(), PE->getEndLoc(),
+                             CloneDrilled(PE->getSubExpr(), C));
+  }
+
+  if (auto *UO = dyn_cast<UnaryOperator>(E)) {
+    if (UO->getOpcode() == UO_Extension) {
+      return UnaryOperator::Create(
+          C, CloneDrilled(UO->getSubExpr(), C), UO_Extension, UO->getType(),
+          UO->getValueKind(), UO->getObjectKind(), UO->getBeginLoc(),
+          UO->canOverflow(), UO->getFPOptionsOverride());
+    }
+  }
+
+  else if (auto *GSE = dyn_cast<GenericSelectionExpr>(E)) {
+    if (!GSE->isResultDependent()) {
+      ArrayRef<Expr *> GSEAEs = GSE->getAssocExprs();
+      Expr **NewGSEAEs = new (C) Expr *[GSEAEs.size()];
+      std::copy(GSEAEs.begin(), GSEAEs.end(), NewGSEAEs);
+      NewGSEAEs[GSE->getResultIndex()] = CloneDrilled(GSE->getResultExpr(), C);
+
+#define CREATE_GSE(ctrl)                                                       \
+  GenericSelectionExpr::Create(                                                \
+      C, GSE->getGenericLoc(), ctrl, GSE->getAssocTypeSourceInfos(),           \
+      ArrayRef<Expr *>(NewGSEAEs, GSEAEs.size()), GSE->getDefaultLoc(),        \
+      GSE->getRParenLoc(), GSE->containsUnexpandedParameterPack(),             \
+      GSE->getResultIndex())
+
+      return GSE->isExprPredicate() ? CREATE_GSE(GSE->getControllingExpr())
+                                    : CREATE_GSE(GSE->getControllingType());
+#undef CREATE_GSE
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awson wrote:

Done

https://github.com/llvm/llvm-project/pull/156846