clang/unittests/Analysis/CloneDetectionTest.cpp

   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 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