[clang] Extend the lifetime of CompilerInvocation in ASTUnit::Parse()

Author: jansvoboda11

clang/include/clang/Frontend/ASTUnit.h

@@ -140,6 +140,10 @@ class ASTUnit {
   /// LoadFromCommandLine available.
   std::shared_ptr<CompilerInvocation> Invocation;
 
+  /// Optional owned invocation, just used to keep the invocation alive for the
+  /// members initialized in transferASTDataFromCompilerInstance.
+  std::shared_ptr<CompilerInvocation> ModifiedInvocation;
+
   /// Fake module loader: the AST unit doesn't need to load any modules.
   TrivialModuleLoader ModuleLoader;
 

clang/lib/Frontend/ASTUnit.cpp

@@ -1501,6 +1501,10 @@ void ASTUnit::transferASTDataFromCompilerInstance(CompilerInstance &CI) {
     Target = &CI.getTarget();
   Reader = CI.getASTReader();
   HadModuleLoaderFatalFailure = CI.hadModuleLoaderFatalFailure();
+  if (Invocation != CI.getInvocationPtr()) {
+    // This happens when Parse creates a copy of \c Invocation to modify.
+    ModifiedInvocation = CI.getInvocationPtr();
+  }
 }
 
 StringRef ASTUnit::getMainFileName() const {