xref: /llvm-project/clang/unittests/Analysis/CloneDetectionTest.cpp (revision 4e600751d2f7e8e7b85a71b7128b68444bdde91b)
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/Analysis/CloneDetection.h"
10 #include "clang/AST/DynamicRecursiveASTVisitor.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 : public DynamicRecursiveASTVisitor {
19 
20   CloneDetector &Detector;
21 
22 public:
23   explicit CloneDetectionVisitor(CloneDetector &D) : Detector(D) {}
24 
25   bool VisitFunctionDecl(FunctionDecl *D) override {
26     Detector.analyzeCodeBody(D);
27     return true;
28   }
29 };
30 
31 /// Example constraint for testing purposes.
32 /// Filters out all statements that are in a function which name starts with
33 /// "bar".
34 class NoBarFunctionConstraint {
35 public:
36   void constrain(std::vector<CloneDetector::CloneGroup> &CloneGroups) {
37     CloneConstraint::splitCloneGroups(
38         CloneGroups, [](const StmtSequence &A, const StmtSequence &B) {
39           // Check if one of the sequences is in a function which name starts
40           // with "bar".
41           for (const StmtSequence &Arg : {A, B}) {
42             if (const auto *D =
43                     dyn_cast<const FunctionDecl>(Arg.getContainingDecl())) {
44               if (D->getName().starts_with("bar"))
45                 return false;
46             }
47           }
48           return true;
49         });
50   }
51 };
52 
53 TEST(CloneDetector, FilterFunctionsByName) {
54   auto ASTUnit =
55       clang::tooling::buildASTFromCode("void foo1(int &a1) { a1++; }\n"
56                                        "void foo2(int &a2) { a2++; }\n"
57                                        "void bar1(int &a3) { a3++; }\n"
58                                        "void bar2(int &a4) { a4++; }\n");
59   auto TU = ASTUnit->getASTContext().getTranslationUnitDecl();
60 
61   CloneDetector Detector;
62   // Push all the function bodies into the detector.
63   CloneDetectionVisitor Visitor(Detector);
64   Visitor.TraverseTranslationUnitDecl(TU);
65 
66   // Find clones with the usual settings, but we want to filter out
67   // all statements from functions which names start with "bar".
68   std::vector<CloneDetector::CloneGroup> CloneGroups;
69   Detector.findClones(CloneGroups, NoBarFunctionConstraint(),
70                       RecursiveCloneTypeIIHashConstraint(),
71                       MinComplexityConstraint(2), MinGroupSizeConstraint(2),
72                       RecursiveCloneTypeIIVerifyConstraint(),
73                       OnlyLargestCloneConstraint());
74 
75   ASSERT_EQ(CloneGroups.size(), 1u);
76   ASSERT_EQ(CloneGroups.front().size(), 2u);
77 
78   for (auto &Clone : CloneGroups.front()) {
79     const auto ND = dyn_cast<const FunctionDecl>(Clone.getContainingDecl());
80     ASSERT_TRUE(ND != nullptr);
81     // Check that no function name starting with "bar" is in the results...
82     ASSERT_TRUE(ND->getNameAsString().find("bar") != 0);
83   }
84 
85   // Retry above's example without the filter...
86   CloneGroups.clear();
87 
88   Detector.findClones(CloneGroups, RecursiveCloneTypeIIHashConstraint(),
89                       MinComplexityConstraint(2), MinGroupSizeConstraint(2),
90                       RecursiveCloneTypeIIVerifyConstraint(),
91                       OnlyLargestCloneConstraint());
92   ASSERT_EQ(CloneGroups.size(), 1u);
93   ASSERT_EQ(CloneGroups.front().size(), 4u);
94 
95   // Count how many functions with the bar prefix we have in the results.
96   int FoundFunctionsWithBarPrefix = 0;
97   for (auto &Clone : CloneGroups.front()) {
98     const auto ND = dyn_cast<const FunctionDecl>(Clone.getContainingDecl());
99     ASSERT_TRUE(ND != nullptr);
100     // This time check that we picked up the bar functions from above
101     if (ND->getNameAsString().find("bar") == 0) {
102       FoundFunctionsWithBarPrefix++;
103     }
104   }
105   // We should have found the two functions bar1 and bar2.
106   ASSERT_EQ(FoundFunctionsWithBarPrefix, 2);
107 }
108 } // namespace
109 } // namespace analysis
110 } // namespace clang
111