[PATCH] D66440: [ORC] fix use-after-free detected by -Wreturn-stack-address

[Matthias Gehre via Phabricator via llvm-commits]

mgehre created this revision.
mgehre added reviewers: lhames, sgraenitz.
Herald added a subscriber: hiraditya.
Herald added a project: LLVM.

llvm/lib/ExecutionEngine/Orc/Layer.cpp:53:12: warning: returning address of local temporary object [-Wreturn-stack-address]

In

  StringRef IRMaterializationUnit::getName() const {
  [...]
       return TSM.withModuleDo(
          [](const Module &M) { return M.getModuleIdentifier(); });

`getModuleIdentifier()` returns a `const std::string &`, but the implicit return type
of the lambda is `std::string` by value, and thus the returned `StringRef` refers
to a temporary `std::string`.

Detect by annotating `llvm::StringRef` with `[[gsl::Pointer]]`.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D66440

Files:
  llvm/lib/ExecutionEngine/Orc/Layer.cpp


Index: llvm/lib/ExecutionEngine/Orc/Layer.cpp
===================================================================
--- llvm/lib/ExecutionEngine/Orc/Layer.cpp
+++ llvm/lib/ExecutionEngine/Orc/Layer.cpp
@@ -51,7 +51,7 @@
 StringRef IRMaterializationUnit::getName() const {
   if (TSM)
     return TSM.withModuleDo(
-        [](const Module &M) { return M.getModuleIdentifier(); });
+        [](const Module &M) -> StringRef { return M.getModuleIdentifier(); });
   return "<null module>";
 }
 


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