xref: /llvm-project/clang/unittests/StaticAnalyzer/IsCLibraryFunctionTest.cpp (revision e1d4ddb0c68f69001d7de43d9c678f4d73c1ecba)
1 #include "clang/ASTMatchers/ASTMatchFinder.h"
2 #include "clang/ASTMatchers/ASTMatchers.h"
3 #include "clang/Analysis/AnalysisDeclContext.h"
4 #include "clang/Frontend/ASTUnit.h"
5 #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
6 #include "clang/Tooling/Tooling.h"
7 #include "gtest/gtest.h"
8 
9 #include <memory>
10 
11 using namespace clang;
12 using namespace ento;
13 using namespace ast_matchers;
14 
15 class IsCLibraryFunctionTest : public testing::Test {
16   std::unique_ptr<ASTUnit> ASTUnitP;
17   const FunctionDecl *Result = nullptr;
18 
19 public:
getFunctionDecl() const20   const FunctionDecl *getFunctionDecl() const { return Result; }
21 
buildAST(StringRef Code)22   testing::AssertionResult buildAST(StringRef Code) {
23     ASTUnitP = tooling::buildASTFromCode(Code);
24     if (!ASTUnitP)
25       return testing::AssertionFailure() << "AST construction failed";
26 
27     ASTContext &Context = ASTUnitP->getASTContext();
28     if (Context.getDiagnostics().hasErrorOccurred())
29       return testing::AssertionFailure() << "Compilation error";
30 
31     auto Matches = ast_matchers::match(functionDecl().bind("fn"), Context);
32     if (Matches.empty())
33       return testing::AssertionFailure() << "No function declaration found";
34 
35     if (Matches.size() > 1)
36       return testing::AssertionFailure()
37              << "Multiple function declarations found";
38 
39     Result = Matches[0].getNodeAs<FunctionDecl>("fn");
40     return testing::AssertionSuccess();
41   }
42 };
43 
TEST_F(IsCLibraryFunctionTest,AcceptsGlobal)44 TEST_F(IsCLibraryFunctionTest, AcceptsGlobal) {
45   ASSERT_TRUE(buildAST(R"cpp(void fun();)cpp"));
46   EXPECT_TRUE(CheckerContext::isCLibraryFunction(getFunctionDecl()));
47 }
48 
TEST_F(IsCLibraryFunctionTest,AcceptsExternCGlobal)49 TEST_F(IsCLibraryFunctionTest, AcceptsExternCGlobal) {
50   ASSERT_TRUE(buildAST(R"cpp(extern "C" { void fun(); })cpp"));
51   EXPECT_TRUE(CheckerContext::isCLibraryFunction(getFunctionDecl()));
52 }
53 
TEST_F(IsCLibraryFunctionTest,RejectsNoInlineNoExternalLinkage)54 TEST_F(IsCLibraryFunctionTest, RejectsNoInlineNoExternalLinkage) {
55   // Functions that are neither inlined nor externally visible cannot be C
56   // library functions.
57   ASSERT_TRUE(buildAST(R"cpp(static void fun();)cpp"));
58   EXPECT_FALSE(CheckerContext::isCLibraryFunction(getFunctionDecl()));
59 }
60 
TEST_F(IsCLibraryFunctionTest,RejectsAnonymousNamespace)61 TEST_F(IsCLibraryFunctionTest, RejectsAnonymousNamespace) {
62   ASSERT_TRUE(buildAST(R"cpp(namespace { void fun(); })cpp"));
63   EXPECT_FALSE(CheckerContext::isCLibraryFunction(getFunctionDecl()));
64 }
65 
TEST_F(IsCLibraryFunctionTest,AcceptsStdNamespace)66 TEST_F(IsCLibraryFunctionTest, AcceptsStdNamespace) {
67   ASSERT_TRUE(buildAST(R"cpp(namespace std { void fun(); })cpp"));
68   EXPECT_TRUE(CheckerContext::isCLibraryFunction(getFunctionDecl()));
69 }
70 
TEST_F(IsCLibraryFunctionTest,RejectsOtherNamespaces)71 TEST_F(IsCLibraryFunctionTest, RejectsOtherNamespaces) {
72   ASSERT_TRUE(buildAST(R"cpp(namespace stdx { void fun(); })cpp"));
73   EXPECT_FALSE(CheckerContext::isCLibraryFunction(getFunctionDecl()));
74 }
75 
TEST_F(IsCLibraryFunctionTest,RejectsClassStatic)76 TEST_F(IsCLibraryFunctionTest, RejectsClassStatic) {
77   ASSERT_TRUE(buildAST(R"cpp(class A { static void fun(); };)cpp"));
78   EXPECT_FALSE(CheckerContext::isCLibraryFunction(getFunctionDecl()));
79 }
80 
TEST_F(IsCLibraryFunctionTest,RejectsClassMember)81 TEST_F(IsCLibraryFunctionTest, RejectsClassMember) {
82   ASSERT_TRUE(buildAST(R"cpp(class A { void fun(); };)cpp"));
83   EXPECT_FALSE(CheckerContext::isCLibraryFunction(getFunctionDecl()));
84 }
85