[lldb][test] Free buffers in demangling tests to avoid leaks

[rupprecht]

Test case added by f669b9c / #137793. Note that the DemanglingParts case above also frees the buffer; this new test case is inconsistent.

[llvmbot]

@llvm/pr-subscribers-lldb

Author: Jordan Rupprecht (rupprecht)

Changes

Test case added by f669b9c / #137793. Note that the DemanglingParts case above also frees the buffer; this new test case is inconsistent.

---

Full diff: https://github.com/llvm/llvm-project/pull/142676.diff

1 Files Affected:

• (modified) lldb/unittests/Core/MangledTest.cpp (+4-1)

diff --git a/lldb/unittests/Core/MangledTest.cpp b/lldb/unittests/Core/MangledTest.cpp
index dfdc026521379..e9dfd05459642 100644
--- a/lldb/unittests/Core/MangledTest.cpp
+++ b/lldb/unittests/Core/MangledTest.cpp
@@ -642,8 +642,10 @@ TEST_P(DemanglingInfoCorrectnessTestFixutre, Correctness) {
   // function names.
   if (Root->getKind() !=
           llvm::itanium_demangle::Node::Kind::KFunctionEncoding &&
-      Root->getKind() != llvm::itanium_demangle::Node::Kind::KDotSuffix)
+      Root->getKind() != llvm::itanium_demangle::Node::Kind::KDotSuffix) {
+    std::free(OB.getBuffer());
     return;
+  }
 
   ASSERT_TRUE(OB.NameInfo.hasBasename());
 
@@ -670,6 +672,7 @@ TEST_P(DemanglingInfoCorrectnessTestFixutre, Correctness) {
                        return_right, qualifiers, suffix);
 
   EXPECT_EQ(reconstructed_name, demangled);
+  std::free(OB.getBuffer());
 }
 
 INSTANTIATE_TEST_SUITE_P(

[JDevlieghere]

LGTM. Maybe an opportunity to use a unique_ptr with a custom deleter? Something like:

struct TrackingOutputBufferDeleter {
  void operator()(TrackingOutputBuffer* TOB) {
    if (!TOB)
      return;
    std::free(TOB->getBuffer());
    std::free(TOB);
  }
};

[Michael137]

thanks! i keep forgetting

[rupprecht]

TrackingOutputBufferDeleter

Yes, that would be a good improvement, especially since the test method here has an early return.

I'd like to land this as-is to plug the leak, but I'll start a new branch now w/ that suggestion.

[rupprecht]

LGTM. Maybe an opportunity to use a unique_ptr with a custom deleter? Something like:

struct TrackingOutputBufferDeleter {
  void operator()(TrackingOutputBuffer* TOB) {
    if (!TOB)
      return;
    std::free(TOB->getBuffer());
    std::free(TOB);
  }
};

Sent #142815. The suggestion is almost perfect. The buffer can be free'd, but TOB must be deleted, otherwise there's a mismatch: alloc-dealloc-mismatch (operator new vs free).