Add missing nullptr checks.

GetPersistentExpressionStateForLanguage() can return a nullptr if it
cannot construct a typesystem. This patch adds missing nullptr checks
at all uses.

Inspired by rdar://problem/58317195

Differential Revision: https://reviews.llvm.org/D72413

1 files changed, 8 insertions, 3 deletions

diff --git a/lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionDeclMap.cpp b/lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionDeclMap.cpp
index 6634824be01..a302a73cafc 100644
--- a/lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionDeclMap.cpp
+++ b/lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionDeclMap.cpp
@@ -126,7 +126,7 @@ void ClangExpressionDeclMap::InstallCodeGenerator(
 }
 
 void ClangExpressionDeclMap::DidParse() {
-  if (m_parser_vars) {
+  if (m_parser_vars && m_parser_vars->m_persistent_vars) {
     for (size_t entity_index = 0, num_entities = m_found_entities.GetSize();
          entity_index < num_entities; ++entity_index) {
       ExpressionVariableSP var_sp(
@@ -262,6 +262,9 @@ bool ClangExpressionDeclMap::AddPersistentVariable(const NamedDecl *decl,
   if (!m_parser_vars->m_target_info.IsValid())
     return false;
 
+  if (!m_parser_vars->m_persistent_vars)
+    return false;
+
   ClangExpressionVariable *var = llvm::cast<ClangExpressionVariable>(
       m_parser_vars->m_persistent_vars
           ->CreatePersistentVariable(
@@ -327,7 +330,7 @@ bool ClangExpressionDeclMap::AddValueToStruct(const NamedDecl *decl,
   ClangExpressionVariable *var(ClangExpressionVariable::FindVariableInList(
       m_found_entities, decl, GetParserID()));
 
-  if (!var) {
+  if (!var && m_parser_vars->m_persistent_vars) {
     var = ClangExpressionVariable::FindVariableInList(
         *m_parser_vars->m_persistent_vars, decl, GetParserID());
     is_persistent_variable = true;
@@ -733,6 +736,8 @@ clang::NamedDecl *ClangExpressionDeclMap::GetPersistentDecl(ConstString name) {
 
   ClangASTContext::GetScratch(*target);
 
+  if (!m_parser_vars->m_persistent_vars)
+    return nullptr;
   return m_parser_vars->m_persistent_vars->GetPersistentDecl(name);
 }
 
@@ -1390,7 +1395,7 @@ void ClangExpressionDeclMap::FindExternalVisibleDecls(
       return;
 
     // No ParserVars means we can't do register or variable lookup.
-    if (!m_parser_vars)
+    if (!m_parser_vars || !m_parser_vars->m_persistent_vars)
       return;
 
     ExpressionVariableSP pvar_sp(