[clang] [LifetimeSafety] Track STL algorithm functions that return lifetimebound iterators (PR #179227)

[Gábor Horváth via cfe-commits]

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@@ -174,13 +174,41 @@ bool shouldTrackImplicitObjectArg(const CXXMethodDecl *Callee,
 }
 
 bool shouldTrackFirstArgument(const FunctionDecl *FD) {
-  if (!FD->getIdentifier() || FD->getNumParams() != 1)
+  if (!FD->getIdentifier() || FD->getNumParams() < 1)
     return false;
+  if (!FD->isInStdNamespace())
+    return false;
+  // Track std:: algorithm functions that return an iterator whose lifetime is
+  // bound to the first argument.
+  if (FD->getNumParams() >= 2 && FD->isInStdNamespace() &&
+      isGslPointerType(FD->getReturnType())) {
+    if (llvm::StringSwitch<bool>(FD->getName())
+            .Cases(
+                {
+                    "find",
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Xazax-hun wrote:

How comprehensive do we want to be here?

There are the `ranges` variants. 

And some more STL functions that modify the container like `rotate`, or `partition` also return iterators that are lifetime dependent.

That being said, I am also fine landing support for some of those in a follow-up. 

https://github.com/llvm/llvm-project/pull/179227