[Clang] Extend the number of case Sema::CheckForIntOverflow covers

Currently Sema::CheckForIntOverflow misses several case that other compilers
diagnose for overflow in integral constant expressions. This includes the
arguments of a CXXConstructExpr as well as the expressions used in an
ArraySubscriptExpr, CXXNewExpr and CompoundLiteralExpr.

This fixes https://github.com/llvm/llvm-project/issues/58944

Differential Revision: https://reviews.llvm.org/D137897

1 files changed, 11 insertions, 0 deletions

diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index f46a4d3..5a9c175 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -14660,6 +14660,17 @@ void Sema::CheckForIntOverflow (Expr *E) {
       Exprs.append(Call->arg_begin(), Call->arg_end());
     else if (auto Message = dyn_cast<ObjCMessageExpr>(E))
       Exprs.append(Message->arg_begin(), Message->arg_end());
+    else if (auto Construct = dyn_cast<CXXConstructExpr>(E))
+      Exprs.append(Construct->arg_begin(), Construct->arg_end());
+    else if (auto Array = dyn_cast<ArraySubscriptExpr>(E))
+      Exprs.push_back(Array->getIdx());
+    else if (auto Compound = dyn_cast<CompoundLiteralExpr>(E))
+      Exprs.push_back(Compound->getInitializer());
+    else if (auto New = dyn_cast<CXXNewExpr>(E)) {
+      if (New->isArray())
+        if (auto ArraySize = New->getArraySize())
+          Exprs.push_back(ArraySize.value());
+    }
   } while (!Exprs.empty());
 }