Don't create a SwiftASTContext just for ClearModuleDependentCaches() (NFC)

Author: adrian-prantl

lldb/source/Plugins/TypeSystem/Swift/TypeSystemSwiftTypeRef.cpp

@@ -1335,13 +1335,18 @@ SwiftASTContext *TypeSystemSwiftTypeRef::GetSwiftASTContext() const {
   return m_swift_ast_context;
 }
 
+SwiftASTContext *TypeSystemSwiftTypeRef::GetSwiftASTContextOrNull() const {
+  return m_swift_ast_context;
+}
+
 void TypeSystemSwiftTypeRef::SetTriple(const llvm::Triple triple) {
   if (auto *swift_ast_context = GetSwiftASTContext())
     swift_ast_context->SetTriple(triple);
 }
 
 void TypeSystemSwiftTypeRef::ClearModuleDependentCaches() {
-  if (auto *swift_ast_context = GetSwiftASTContext())
+  // There is no need to notify a not-yet created SwiftASTContext to reset.
+  if (auto *swift_ast_context = GetSwiftASTContextOrNull())
     swift_ast_context->ClearModuleDependentCaches();
 }
 const char *TypeSystemSwiftTypeRef::AsMangledName(opaque_compiler_type_t type) {

lldb/source/Plugins/TypeSystem/Swift/TypeSystemSwiftTypeRef.h

@@ -57,7 +57,10 @@ class TypeSystemSwiftTypeRef : public TypeSystemSwift {
   ~TypeSystemSwiftTypeRef();
   TypeSystemSwiftTypeRef(Module &module);
   TypeSystemSwiftTypeRef(SwiftASTContextForExpressions &swift_ast_context);
+  /// Get the corresponding SwiftASTContext, and create one if necessary.
   SwiftASTContext *GetSwiftASTContext() const override;
+  /// Return SwiftASTContext, iff one has already been created.
+  SwiftASTContext *GetSwiftASTContextOrNull() const;
   TypeSystemSwiftTypeRef &GetTypeSystemSwiftTypeRef() override { return *this; }
   void SetTriple(const llvm::Triple triple) override;
   void ClearModuleDependentCaches() override;

lldb/test/API/lang/swift/clangimporter/rewrite_clang_paths/TestSwiftRewriteClangPaths.py

@@ -87,6 +87,8 @@ def dotest(self, remap):
             self.expect("fr var foo", comment, substrs=["x", "23"])
             self.expect("fr var bar", comment, substrs=["y", "42"])
             self.assertTrue(os.path.isdir(mod_cache), "module cache exists")
+        else:
+            self.expect("p foo", error=True)
 
         # Scan through the types log.
         errs = 0

lldb/test/API/lang/swift/parseable_interfaces/shared/TestSwiftInterfaceNoDebugInfo.py

@@ -59,6 +59,7 @@ def test_prebuilt_cache_location(self):
         lldbutil.run_to_source_breakpoint(
            self, "break here", lldb.SBFileSpec("main.swift"),
            exe_name=self.getBuildArtifact("main"))
+        self.expect("expr 1")
 
         # Check the prebuilt cache path in the log output
         prefix = 'Using prebuilt Swift module cache path: '