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/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