[llvm] [ObjectSizeOffsetVisitor] Add a max recursion depth (PR #67479)

[Nikita Popov via llvm-commits]

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@@ -994,14 +1001,20 @@ SizeOffsetType ObjectSizeOffsetVisitor::combineSizeOffset(SizeOffsetType LHS,
 }
 
 SizeOffsetType ObjectSizeOffsetVisitor::visitPHINode(PHINode &PN) {
-  if (PN.getNumIncomingValues() == 0)
+  if (PN.getNumIncomingValues() == 0 ||
+      RecurseDepth >= ObjectSizeOffsetVisitorMaxRecurseDepth)
     return unknown();
+
+  ++RecurseDepth;
   auto IncomingValues = PN.incoming_values();
-  return std::accumulate(IncomingValues.begin() + 1, IncomingValues.end(),
-                         compute(*IncomingValues.begin()),
-                         [this](SizeOffsetType LHS, Value *VRHS) {
-                           return combineSizeOffset(LHS, compute(VRHS));
-                         });
+  SizeOffsetType Ret =
+      std::accumulate(IncomingValues.begin() + 1, IncomingValues.end(),
+                      compute(*IncomingValues.begin()),
+                      [this](SizeOffsetType LHS, Value *VRHS) {
+                        return combineSizeOffset(LHS, compute(VRHS));
+                      });
+  --RecurseDepth;
+  return Ret;
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nikic wrote:

Do the same for selects?

https://github.com/llvm/llvm-project/pull/67479