Add a unittest for the ExternalASTSource.

llvm-svn: 203525

clang/unittests/AST/CMakeLists.txt

@@ -10,6 +10,7 @@ add_clang_unittest(ASTTests
   CommentParser.cpp
   DeclPrinterTest.cpp
   DeclTest.cpp
+  ExternalASTSourceTest.cpp
   SourceLocationTest.cpp
   StmtPrinterTest.cpp
   )

clang/unittests/AST/ExternalASTSourceTest.cpp

@@ -0,0 +1,83 @@
+//===- unittest/AST/ExternalASTSourceTest.cpp -----------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains tests for Clang's ExternalASTSource.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/AST/ASTConsumer.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/ExternalASTSource.h"
+#include "clang/Frontend/CompilerInstance.h"
+#include "clang/Frontend/CompilerInvocation.h"
+#include "clang/Frontend/FrontendActions.h"
+#include "gtest/gtest.h"
+
+using namespace clang;
+using namespace llvm;
+
+
+class TestFrontendAction : public ASTFrontendAction {
+public:
+  TestFrontendAction(ExternalASTSource *Source) : Source(Source) {}
+
+private:
+  virtual void ExecuteAction() {
+    getCompilerInstance().getASTContext().setExternalSource(Source);
+    getCompilerInstance().getASTContext().getTranslationUnitDecl()
+        ->setHasExternalVisibleStorage();
+    return ASTFrontendAction::ExecuteAction();
+  }
+
+  virtual ASTConsumer *CreateASTConsumer(CompilerInstance &CI,
+                                         StringRef InFile) {
+    return new ASTConsumer;
+  }
+
+  IntrusiveRefCntPtr<ExternalASTSource> Source;
+};
+
+bool testExternalASTSource(ExternalASTSource *Source,
+                           StringRef FileContents) {
+  CompilerInstance Compiler;
+  Compiler.createDiagnostics();
+
+  CompilerInvocation *Invocation = new CompilerInvocation;
+  Invocation->getPreprocessorOpts().addRemappedFile(
+    "test.cc", MemoryBuffer::getMemBuffer(FileContents));
+  const char *Args[] = { "test.cc" };
+  CompilerInvocation::CreateFromArgs(*Invocation, Args,
+                                     Args + array_lengthof(Args),
+                                     Compiler.getDiagnostics());
+  Compiler.setInvocation(Invocation);
+
+  TestFrontendAction Action(Source);
+  return Compiler.ExecuteAction(Action);
+}
+
+
+// Ensure that a failed name lookup into an external source only occurs once.
+TEST(ExternalASTSourceTest, FailedLookupOccursOnce) {
+  struct TestSource : ExternalASTSource {
+    TestSource(unsigned &Calls) : Calls(Calls) {}
+
+    bool FindExternalVisibleDeclsByName(const DeclContext*,
+                                        DeclarationName Name) {
+      if (Name.getAsString() == "j")
+        ++Calls;
+      return false;
+    }
+
+    unsigned &Calls;
+  };
+
+  unsigned Calls;
+  ASSERT_TRUE(testExternalASTSource(new TestSource(Calls), "int j, k = j;"));
+  EXPECT_EQ(1u, Calls);
+}