1 //===- unittests/Analysis/CFGTest.cpp - CFG tests -------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "clang/ASTMatchers/ASTMatchFinder.h"
11 #include "clang/Analysis/CFG.h"
12 #include "clang/Tooling/Tooling.h"
13 #include "gtest/gtest.h"
14 #include <string>
15 #include <vector>
16 
17 namespace clang {
18 namespace analysis {
19 namespace {
20 
21 enum BuildResult {
22   ToolFailed,
23   ToolRan,
24   SawFunctionBody,
25   BuiltCFG,
26 };
27 
28 class CFGCallback : public ast_matchers::MatchFinder::MatchCallback {
29 public:
30   BuildResult TheBuildResult = ToolRan;
31 
32   void run(const ast_matchers::MatchFinder::MatchResult &Result) override {
33     const auto *Func = Result.Nodes.getNodeAs<FunctionDecl>("func");
34     Stmt *Body = Func->getBody();
35     if (!Body)
36       return;
37     TheBuildResult = SawFunctionBody;
38     CFG::BuildOptions Options;
39     Options.AddImplicitDtors = true;
40     if (CFG::buildCFG(nullptr, Body, Result.Context, Options))
41         TheBuildResult = BuiltCFG;
42   }
43 };
44 
45 BuildResult BuildCFG(const char *Code) {
46   CFGCallback Callback;
47 
48   ast_matchers::MatchFinder Finder;
49   Finder.addMatcher(ast_matchers::functionDecl().bind("func"), &Callback);
50   std::unique_ptr<tooling::FrontendActionFactory> Factory(
51       tooling::newFrontendActionFactory(&Finder));
52   std::vector<std::string> Args = {"-std=c++11", "-fno-delayed-template-parsing"};
53   if (!tooling::runToolOnCodeWithArgs(Factory->create(), Code, Args))
54     return ToolFailed;
55   return Callback.TheBuildResult;
56 }
57 
58 // Constructing a CFG for a range-based for over a dependent type fails (but
59 // should not crash).
60 TEST(CFG, RangeBasedForOverDependentType) {
61   const char *Code = "class Foo;\n"
62                      "template <typename T>\n"
63                      "void f(const T &Range) {\n"
64                      "  for (const Foo *TheFoo : Range) {\n"
65                      "  }\n"
66                      "}\n";
67   EXPECT_EQ(SawFunctionBody, BuildCFG(Code));
68 }
69 
70 // Constructing a CFG containing a delete expression on a dependent type should
71 // not crash.
72 TEST(CFG, DeleteExpressionOnDependentType) {
73   const char *Code = "template<class T>\n"
74                      "void f(T t) {\n"
75                      "  delete t;\n"
76                      "}\n";
77   EXPECT_EQ(BuiltCFG, BuildCFG(Code));
78 }
79 
80 // Constructing a CFG on a function template with a variable of incomplete type
81 // should not crash.
82 TEST(CFG, VariableOfIncompleteType) {
83   const char *Code = "template<class T> void f() {\n"
84                      "  class Undefined;\n"
85                      "  Undefined u;\n"
86                      "}\n";
87   EXPECT_EQ(BuiltCFG, BuildCFG(Code));
88 }
89 
90 } // namespace
91 } // namespace analysis
92 } // namespace clang
93