xref: /llvm-project/clang/unittests/Serialization/VarDeclConstantInitTest.cpp (revision df9a14d7bbf1180e4f1474254c9d7ed6bcb4ce55)
1 //===- unittests/Serialization/VarDeclConstantInitTest.cpp - CI tests -----===//
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 #include "clang/ASTMatchers/ASTMatchFinder.h"
10 #include "clang/ASTMatchers/ASTMatchers.h"
11 #include "clang/Basic/FileManager.h"
12 #include "clang/Frontend/CompilerInstance.h"
13 #include "clang/Frontend/CompilerInvocation.h"
14 #include "clang/Frontend/FrontendActions.h"
15 #include "clang/Frontend/Utils.h"
16 #include "clang/Lex/HeaderSearch.h"
17 #include "clang/Tooling/Tooling.h"
18 #include "llvm/ADT/SmallString.h"
19 #include "llvm/Support/FileSystem.h"
20 #include "llvm/Support/raw_ostream.h"
21 
22 #include "gtest/gtest.h"
23 
24 using namespace llvm;
25 using namespace clang;
26 
27 namespace {
28 
29 class VarDeclConstantInitTest : public ::testing::Test {
30   void SetUp() override {
31     ASSERT_FALSE(sys::fs::createUniqueDirectory("modules-test", TestDir));
32   }
33 
34   void TearDown() override { sys::fs::remove_directories(TestDir); }
35 
36 public:
37   SmallString<256> TestDir;
38 
39   void addFile(StringRef Path, StringRef Contents) {
40     ASSERT_FALSE(sys::path::is_absolute(Path));
41 
42     SmallString<256> AbsPath(TestDir);
43     sys::path::append(AbsPath, Path);
44 
45     ASSERT_FALSE(
46         sys::fs::create_directories(llvm::sys::path::parent_path(AbsPath)));
47 
48     std::error_code EC;
49     llvm::raw_fd_ostream OS(AbsPath, EC);
50     ASSERT_FALSE(EC);
51     OS << Contents;
52   }
53 };
54 
55 TEST_F(VarDeclConstantInitTest, CachedConstantInit) {
56   addFile("Cached.cppm", R"cpp(
57 export module Fibonacci.Cache;
58 
59 export namespace Fibonacci
60 {
61 	constexpr unsigned long Recursive(unsigned long n)
62 	{
63 		if (n == 0)
64 			return 0;
65 		if (n == 1)
66 			return 1;
67 		return Recursive(n - 2) + Recursive(n - 1);
68 	}
69 
70 	template<unsigned long N>
71 	struct Number{};
72 
73 	struct DefaultStrategy
74 	{
75 		constexpr unsigned long operator()(unsigned long n, auto... other) const
76 		{
77 			return (n + ... + other);
78 		}
79 	};
80 
81   constexpr unsigned long Compute(Number<10ul>, auto strategy)
82 	{
83 		return strategy(Recursive(10ul));
84 	}
85 
86 	template<unsigned long N, typename Strategy = DefaultStrategy>
87 	constexpr unsigned long Cache = Compute(Number<N>{}, Strategy{});
88 
89   template constexpr unsigned long Cache<10ul>;
90 }
91   )cpp");
92 
93   CreateInvocationOptions CIOpts;
94   CIOpts.VFS = llvm::vfs::createPhysicalFileSystem();
95   IntrusiveRefCntPtr<DiagnosticsEngine> Diags =
96       CompilerInstance::createDiagnostics(*CIOpts.VFS, new DiagnosticOptions());
97   CIOpts.Diags = Diags;
98 
99   const char *Args[] = {"clang++",       "-std=c++20",
100                         "--precompile",  "-working-directory",
101                         TestDir.c_str(), "Cached.cppm"};
102   std::shared_ptr<CompilerInvocation> Invocation =
103       createInvocation(Args, CIOpts);
104   ASSERT_TRUE(Invocation);
105   Invocation->getFrontendOpts().DisableFree = false;
106 
107   CompilerInstance Instance;
108   Instance.setDiagnostics(Diags.get());
109   Instance.setInvocation(Invocation);
110 
111   std::string CacheBMIPath = llvm::Twine(TestDir + "/Cached.pcm").str();
112   Instance.getFrontendOpts().OutputFile = CacheBMIPath;
113 
114   GenerateReducedModuleInterfaceAction Action;
115   ASSERT_TRUE(Instance.ExecuteAction(Action));
116   ASSERT_FALSE(Diags->hasErrorOccurred());
117 
118   std::string DepArg =
119       llvm::Twine("-fmodule-file=Fibonacci.Cache=" + CacheBMIPath).str();
120   std::unique_ptr<ASTUnit> AST = tooling::buildASTFromCodeWithArgs(
121       R"cpp(
122 import Fibonacci.Cache;
123         )cpp",
124       /*Args=*/{"-std=c++20", DepArg.c_str()});
125 
126   using namespace clang::ast_matchers;
127   ASTContext &Ctx = AST->getASTContext();
128   const auto *cached = selectFirst<VarDecl>(
129       "Cache",
130       match(varDecl(isTemplateInstantiation(), hasName("Cache")).bind("Cache"),
131             Ctx));
132   EXPECT_TRUE(cached);
133   EXPECT_TRUE(cached->getEvaluatedStmt());
134   EXPECT_TRUE(cached->getEvaluatedStmt()->WasEvaluated);
135   EXPECT_TRUE(cached->getEvaluatedValue());
136   EXPECT_TRUE(cached->getEvaluatedValue()->isInt());
137   EXPECT_EQ(cached->getEvaluatedValue()->getInt(), 55);
138 }
139 
140 } // anonymous namespace
141