From 793d8d9c006de8a2fcdb3047d7a49194a1146862 Mon Sep 17 00:00:00 2001 From: Jim Ingham Date: Fri, 6 Dec 2013 22:21:04 +0000 Subject: [PATCH] Do a little more prevention against SBValues getting used after the world has been torn down around them. llvm-svn: 196616 --- lldb/source/API/SBValue.cpp | 23 +++++++++++++++++++++-- 1 file changed, 21 insertions(+), 2 deletions(-) diff --git a/lldb/source/API/SBValue.cpp b/lldb/source/API/SBValue.cpp index 51b6790dd2b8..4bd018352ff2 100644 --- a/lldb/source/API/SBValue.cpp +++ b/lldb/source/API/SBValue.cpp @@ -96,7 +96,24 @@ public: bool IsValid () { - return m_valobj_sp.get() != NULL; + if (m_valobj_sp.get() == NULL) + return false; + else + { + // FIXME: This check is necessary but not sufficient. We for sure don't want to touch SBValues whose owning + // targets have gone away. This check is a little weak in that it enforces that restriction when you call + // IsValid, but since IsValid doesn't lock the target, you have no guarantee that the SBValue won't go + // invalid after you call this... + // Also, an SBValue could depend on data from one of the modules in the target, and those could go away + // independently of the target, for instance if a module is unloaded. But right now, neither SBValues + // nor ValueObjects know which modules they depend on. So I have no good way to make that check without + // tracking that in all the ValueObject subclasses. + TargetSP target_sp = m_valobj_sp->GetTargetSP(); + if (target_sp && target_sp->IsValid()) + return true; + else + return false; + } } lldb::ValueObjectSP @@ -120,6 +137,8 @@ public: Target *target = value_sp->GetTargetSP().get(); if (target) api_locker.Lock(target->GetAPIMutex()); + else + return ValueObjectSP(); ProcessSP process_sp(value_sp->GetProcessSP()); if (process_sp && !stop_locker.TryLock (&process_sp->GetRunLock())) @@ -276,7 +295,7 @@ SBValue::IsValid () // If this function ever changes to anything that does more than just // check if the opaque shared pointer is non NULL, then we need to update // all "if (m_opaque_sp)" code in this file. - return m_opaque_sp.get() != NULL && m_opaque_sp->GetRootSP().get() != NULL; + return m_opaque_sp.get() != NULL && m_opaque_sp->IsValid() && m_opaque_sp->GetRootSP().get() != NULL; } void