[Clang] [Sema] Document invariant in Sema::AddOverloadCandidate (#135256)

shafik · web-flow · commit ffac1404f8e0 · 2025-04-11T08:38:37.000-07:00
Static analysis flagged 1 - ArgIdx in Sema::AddOverloadCandidate for its potential to overflow. Turns out this is intentional since when PO == OverloadCandidateParamOrder::Reversed Args.size() is always two, so this will never overflow. We document using an assert. Fixes: #135086
diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp
@@ -7189,6 +7189,7 @@ void Sema::AddOverloadCandidate(
     }
   }
 
+  assert(PO != OverloadCandidateParamOrder::Reversed || Args.size() == 2);
   // Determine the implicit conversion sequences for each of the
   // arguments.
   for (unsigned ArgIdx = 0; ArgIdx < Args.size(); ++ArgIdx) {

Original file line number	Diff line number	Diff line change
`@@ -7189,6 +7189,7 @@ void Sema::AddOverloadCandidate(`
`7189`	`7189`	`}`
`7190`	`7190`	`}`
`7191`	`7191`
	`7192`	`+ assert(PO != OverloadCandidateParamOrder::Reversed \|\| Args.size() == 2);`
`7192`	`7193`	`// Determine the implicit conversion sequences for each of the`
`7193`	`7194`	`// arguments.`
`7194`	`7195`	`for (unsigned ArgIdx = 0; ArgIdx < Args.size(); ++ArgIdx) {`