1 //===- unittest/AST/ExternalASTSourceTest.cpp -----------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file contains tests for Clang's ExternalASTSource.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "clang/AST/ASTConsumer.h"
14 #include "clang/AST/ASTContext.h"
15 #include "clang/AST/ExternalASTSource.h"
16 #include "clang/Frontend/CompilerInstance.h"
17 #include "clang/Frontend/CompilerInvocation.h"
18 #include "clang/Frontend/FrontendActions.h"
19 #include "clang/Lex/PreprocessorOptions.h"
20 #include "gtest/gtest.h"
21 
22 using namespace clang;
23 using namespace llvm;
24 
25 
26 class TestFrontendAction : public ASTFrontendAction {
27 public:
28   TestFrontendAction(ExternalASTSource *Source) : Source(Source) {}
29 
30 private:
31   void ExecuteAction() override {
32     getCompilerInstance().getASTContext().setExternalSource(Source);
33     getCompilerInstance().getASTContext().getTranslationUnitDecl()
34         ->setHasExternalVisibleStorage();
35     return ASTFrontendAction::ExecuteAction();
36   }
37 
38   std::unique_ptr<ASTConsumer> CreateASTConsumer(CompilerInstance &CI,
39                                                  StringRef InFile) override {
40     return std::make_unique<ASTConsumer>();
41   }
42 
43   IntrusiveRefCntPtr<ExternalASTSource> Source;
44 };
45 
46 bool testExternalASTSource(ExternalASTSource *Source,
47                            StringRef FileContents) {
48   CompilerInstance Compiler;
49   Compiler.createDiagnostics();
50 
51   auto Invocation = std::make_shared<CompilerInvocation>();
52   Invocation->getPreprocessorOpts().addRemappedFile(
53       "test.cc", MemoryBuffer::getMemBuffer(FileContents).release());
54   const char *Args[] = { "test.cc" };
55   CompilerInvocation::CreateFromArgs(*Invocation, Args,
56                                      Compiler.getDiagnostics());
57   Compiler.setInvocation(std::move(Invocation));
58 
59   TestFrontendAction Action(Source);
60   return Compiler.ExecuteAction(Action);
61 }
62 
63 
64 // Ensure that a failed name lookup into an external source only occurs once.
65 TEST(ExternalASTSourceTest, FailedLookupOccursOnce) {
66   struct TestSource : ExternalASTSource {
67     TestSource(unsigned &Calls) : Calls(Calls) {}
68 
69     bool FindExternalVisibleDeclsByName(const DeclContext *,
70                                         DeclarationName Name) override {
71       if (Name.getAsString() == "j")
72         ++Calls;
73       return false;
74     }
75 
76     unsigned &Calls;
77   };
78 
79   unsigned Calls = 0;
80   ASSERT_TRUE(testExternalASTSource(new TestSource(Calls), "int j, k = j;"));
81   EXPECT_EQ(1u, Calls);
82 }
83