1 //===- unittests/Analysis/CloneDetectionTest.cpp - Clone detection 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/AST/RecursiveASTVisitor.h"
10 #include "clang/Analysis/CloneDetection.h"
11 #include "clang/Tooling/Tooling.h"
12 #include "gtest/gtest.h"
13 
14 namespace clang {
15 namespace analysis {
16 namespace {
17 
18 class CloneDetectionVisitor
19     : public RecursiveASTVisitor<CloneDetectionVisitor> {
20 
21   CloneDetector &Detector;
22 
23 public:
24   explicit CloneDetectionVisitor(CloneDetector &D) : Detector(D) {}
25 
26   bool VisitFunctionDecl(FunctionDecl *D) {
27     Detector.analyzeCodeBody(D);
28     return true;
29   }
30 };
31 
32 /// Example constraint for testing purposes.
33 /// Filters out all statements that are in a function which name starts with
34 /// "bar".
35 class NoBarFunctionConstraint {
36 public:
37   void constrain(std::vector<CloneDetector::CloneGroup> &CloneGroups) {
38     CloneConstraint::splitCloneGroups(
39         CloneGroups, [](const StmtSequence &A, const StmtSequence &B) {
40           // Check if one of the sequences is in a function which name starts
41           // with "bar".
42           for (const StmtSequence &Arg : {A, B}) {
43             if (const auto *D =
44                     dyn_cast<const FunctionDecl>(Arg.getContainingDecl())) {
45               if (D->getName().startswith("bar"))
46                 return false;
47             }
48           }
49           return true;
50         });
51   }
52 };
53 
54 TEST(CloneDetector, FilterFunctionsByName) {
55   auto ASTUnit =
56       clang::tooling::buildASTFromCode("void foo1(int &a1) { a1++; }\n"
57                                        "void foo2(int &a2) { a2++; }\n"
58                                        "void bar1(int &a3) { a3++; }\n"
59                                        "void bar2(int &a4) { a4++; }\n");
60   auto TU = ASTUnit->getASTContext().getTranslationUnitDecl();
61 
62   CloneDetector Detector;
63   // Push all the function bodies into the detector.
64   CloneDetectionVisitor Visitor(Detector);
65   Visitor.TraverseTranslationUnitDecl(TU);
66 
67   // Find clones with the usual settings, but but we want to filter out
68   // all statements from functions which names start with "bar".
69   std::vector<CloneDetector::CloneGroup> CloneGroups;
70   Detector.findClones(CloneGroups, NoBarFunctionConstraint(),
71                       RecursiveCloneTypeIIHashConstraint(),
72                       MinComplexityConstraint(2), MinGroupSizeConstraint(2),
73                       RecursiveCloneTypeIIVerifyConstraint(),
74                       OnlyLargestCloneConstraint());
75 
76   ASSERT_EQ(CloneGroups.size(), 1u);
77   ASSERT_EQ(CloneGroups.front().size(), 2u);
78 
79   for (auto &Clone : CloneGroups.front()) {
80     const auto ND = dyn_cast<const FunctionDecl>(Clone.getContainingDecl());
81     ASSERT_TRUE(ND != nullptr);
82     // Check that no function name starting with "bar" is in the results...
83     ASSERT_TRUE(ND->getNameAsString().find("bar") != 0);
84   }
85 
86   // Retry above's example without the filter...
87   CloneGroups.clear();
88 
89   Detector.findClones(CloneGroups, RecursiveCloneTypeIIHashConstraint(),
90                       MinComplexityConstraint(2), MinGroupSizeConstraint(2),
91                       RecursiveCloneTypeIIVerifyConstraint(),
92                       OnlyLargestCloneConstraint());
93   ASSERT_EQ(CloneGroups.size(), 1u);
94   ASSERT_EQ(CloneGroups.front().size(), 4u);
95 
96   // Count how many functions with the bar prefix we have in the results.
97   int FoundFunctionsWithBarPrefix = 0;
98   for (auto &Clone : CloneGroups.front()) {
99     const auto ND = dyn_cast<const FunctionDecl>(Clone.getContainingDecl());
100     ASSERT_TRUE(ND != nullptr);
101     // This time check that we picked up the bar functions from above
102     if (ND->getNameAsString().find("bar") == 0) {
103       FoundFunctionsWithBarPrefix++;
104     }
105   }
106   // We should have found the two functions bar1 and bar2.
107   ASSERT_EQ(FoundFunctionsWithBarPrefix, 2);
108 }
109 } // namespace
110 } // namespace analysis
111 } // namespace clang
112