[clang] [Lifetime Safety] Highlight lifetimebound calls in alias chain diagnostics (PR #206337)

[Gábor Horváth via cfe-commits]

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@@ -526,14 +527,15 @@ class LifetimeChecker {
   /// Given a chain of origins that shows how a loan propagates, this function
   /// extracts the corresponding expressions for each origin. Origins that refer
   /// to declarations (rather than expressions) are skipped.
-  llvm::SmallVector<const Expr *>
-  getExprChain(llvm::ArrayRef<OriginID> OriginFlowChain) {
-    llvm::SmallVector<const Expr *> rs;
-    for (const OriginID CurrOID : OriginFlowChain)
-      if (const Expr *CurrExpr =
-              FactMgr.getOriginMgr().getOrigin(CurrOID).getExpr())
-        rs.push_back(CurrExpr);
-    return rs;
+  llvm::SmallVector<AliasChainEntry>
+  getAliasChain(llvm::ArrayRef<const OriginFlowFact *> OriginFlowChain) {
+    llvm::SmallVector<AliasChainEntry> Result;
+    for (const OriginFlowFact *Flow : OriginFlowChain)
+      if (const Expr *CurrExpr = FactMgr.getOriginMgr()
+                                     .getOrigin(Flow->getSrcOriginID())
+                                     .getExpr())
+        Result.push_back({CurrExpr, FactMgr.getLifetimeBoundParamInfo(Flow)});
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Xazax-hun wrote:

This function makes me think, do we actually need to store the `LifetimeBoundInfo`?

I wonder if we can rederive it here from the expression instead. You could factor `GetLifetimeBoundParamInfo` from the `handleFunctionCall` out and call it here.

This would save us on memory, and insert/lookup on the hot path (the analysis itself), and instead we would do work on the cold path (reporting warnings). 

https://github.com/llvm/llvm-project/pull/206337