[Lldb-commits] [lldb] 1dd9162 - [lldb] Fix a crasher when using the public API. (#80508)

[via lldb-commits]

Author: Greg Clayton
Date: 2024-02-06T13:53:29-08:00
New Revision: 1dd9162b95d29367635f32c7be24779b1ddaa7e5

URL: https://github.com/llvm/llvm-project/commit/1dd9162b95d29367635f32c7be24779b1ddaa7e5
DIFF: https://github.com/llvm/llvm-project/commit/1dd9162b95d29367635f32c7be24779b1ddaa7e5.diff

LOG: [lldb] Fix a crasher when using the public API. (#80508)

A user found a crash when they would do code like:
```
(lldb) script
>>> target = lldb.SBTarget()
>>> lldb.debugger.SetSelectedTarget(target)
```

We were not checking if the target was valid in and it caused a crash..

Added: 
    

Modified: 
    lldb/source/Target/TargetList.cpp
    lldb/test/API/python_api/target/TestTargetAPI.py

Removed: 
    


################################################################################
diff  --git a/lldb/source/Target/TargetList.cpp b/lldb/source/Target/TargetList.cpp
index 121b6253d2a59d..b5d308739d0fac 100644
--- a/lldb/source/Target/TargetList.cpp
+++ b/lldb/source/Target/TargetList.cpp
@@ -532,9 +532,13 @@ void TargetList::SetSelectedTarget(uint32_t index) {
 }
 
 void TargetList::SetSelectedTarget(const TargetSP &target_sp) {
-  std::lock_guard<std::recursive_mutex> guard(m_target_list_mutex);
-  auto it = llvm::find(m_target_list, target_sp);
-  SetSelectedTargetInternal(std::distance(m_target_list.begin(), it));
+  // Don't allow an invalid target shared pointer or a target that has been
+  // destroyed to become the selected target.
+  if (target_sp && target_sp->IsValid()) {
+    std::lock_guard<std::recursive_mutex> guard(m_target_list_mutex);
+    auto it = llvm::find(m_target_list, target_sp);
+    SetSelectedTargetInternal(std::distance(m_target_list.begin(), it));
+  }
 }
 
 lldb::TargetSP TargetList::GetSelectedTarget() {

diff  --git a/lldb/test/API/python_api/target/TestTargetAPI.py b/lldb/test/API/python_api/target/TestTargetAPI.py
index c8e1904428c8aa..63d34340a8836e 100644
--- a/lldb/test/API/python_api/target/TestTargetAPI.py
+++ b/lldb/test/API/python_api/target/TestTargetAPI.py
@@ -526,3 +526,9 @@ def test_is_loaded(self):
                 target.IsLoaded(module),
                 "Running the target should " "have loaded its modules.",
             )
+
+    @no_debug_info_test
+    def test_setting_selected_target_with_invalid_target(self):
+        """Make sure we don't crash when trying to select invalid target."""
+        target = lldb.SBTarget()
+        self.dbg.SetSelectedTarget(target)