r276782 - [analyzer] Add basic capabilities to detect source code clones.

Mike Aizatsky via cfe-commits cfe-commits at lists.llvm.org
Tue Jul 26 12:13:43 PDT 2016


Artem,

I think you broke the build. Could you take a look please?

http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-fuzzer/builds/11051
http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-fuzzer/builds/11051/steps/build%20clang/logs/stdio

[80/140] Building CXX object
tools/clang/lib/StaticAnalyzer/Checkers/CMakeFiles/clangStaticAnalyzerCheckers.dir/CloneChecker.cpp.o
FAILED: tools/clang/lib/StaticAnalyzer/Checkers/CMakeFiles/clangStaticAnalyzerCheckers.dir/CloneChecker.cpp.o
/usr/bin/c++   -DCLANG_ENABLE_ARCMT -DCLANG_ENABLE_OBJC_REWRITER
-DCLANG_ENABLE_STATIC_ANALYZER -DGTEST_HAS_RTTI=0 -D_GNU_SOURCE
-D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS
-Itools/clang/lib/StaticAnalyzer/Checkers
-I/mnt/b/sanitizer-buildbot5/sanitizer-x86_64-linux-fuzzer/build/llvm/tools/clang/lib/StaticAnalyzer/Checkers
-I/mnt/b/sanitizer-buildbot5/sanitizer-x86_64-linux-fuzzer/build/llvm/tools/clang/include
-Itools/clang/include -Iinclude
-I/mnt/b/sanitizer-buildbot5/sanitizer-x86_64-linux-fuzzer/build/llvm/include
-fPIC -fvisibility-inlines-hidden -Wall -W -Wno-unused-parameter
-Wwrite-strings -Wcast-qual -Wno-missing-field-initializers -pedantic
-Wno-long-long -Wno-maybe-uninitialized -Wdelete-non-virtual-dtor
-Wno-comment -Werror=date-time -std=c++11 -ffunction-sections
-fdata-sections -fno-common -Woverloaded-virtual -fno-strict-aliasing
-O3 -DNDEBUG    -fno-exceptions -fno-rtti -MMD -MT
tools/clang/lib/StaticAnalyzer/Checkers/CMakeFiles/clangStaticAnalyzerCheckers.dir/CloneChecker.cpp.o
-MF tools/clang/lib/StaticAnalyzer/Checkers/CMakeFiles/clangStaticAnalyzerCheckers.dir/CloneChecker.cpp.o.d
-o tools/clang/lib/StaticAnalyzer/Checkers/CMakeFiles/clangStaticAnalyzerCheckers.dir/CloneChecker.cpp.o
-c /mnt/b/sanitizer-buildbot5/sanitizer-x86_64-linux-fuzzer/build/llvm/tools/clang/lib/StaticAnalyzer/Checkers/CloneChecker.cpp/mnt/b/sanitizer-buildbot5/sanitizer-x86_64-linux-fuzzer/build/llvm/tools/clang/lib/StaticAnalyzer/Checkers/CloneChecker.cpp:29:25:
error: declaration of ‘clang::CloneDetector
{anonymous}::CloneChecker::CloneDetector’ [-fpermissive]
   mutable CloneDetector CloneDetector;
                         ^
In file included from
/mnt/b/sanitizer-buildbot5/sanitizer-x86_64-linux-fuzzer/build/llvm/tools/clang/lib/StaticAnalyzer/Checkers/CloneChecker.cpp:17:0:
/mnt/b/sanitizer-buildbot5/sanitizer-x86_64-linux-fuzzer/build/llvm/tools/clang/include/clang/Analysis/CloneDetection.h:158:7:
error: changes meaning of ‘CloneDetector’ from ‘class
clang::CloneDetector’ [-fpermissive]
 class CloneDetector {
       ^



On Tue, Jul 26, 2016 at 11:28 AM Artem Dergachev via cfe-commits <
cfe-commits at lists.llvm.org> wrote:

> Author: dergachev
> Date: Tue Jul 26 13:13:12 2016
> New Revision: 276782
>
> URL: http://llvm.org/viewvc/llvm-project?rev=276782&view=rev
> Log:
> [analyzer] Add basic capabilities to detect source code clones.
>
> This patch adds the CloneDetector class which allows searching source code
> for clones.
>
> For every statement or group of statements within a compound statement,
> CloneDetector computes a hash value, and finds clones by detecting
> identical hash values.
>
> This initial patch only provides a simple hashing mechanism
> that hashes the kind of each sub-statement.
>
> This patch also adds CloneChecker - a simple static analyzer checker
> that uses CloneDetector to report copy-pasted code.
>
> Patch by Raphael Isemann!
>
> Differential Revision: https://reviews.llvm.org/D20795
>
> Added:
>     cfe/trunk/include/clang/Analysis/CloneDetection.h
>     cfe/trunk/lib/Analysis/CloneDetection.cpp
>     cfe/trunk/lib/StaticAnalyzer/Checkers/CloneChecker.cpp
>     cfe/trunk/test/Analysis/copypaste/
>     cfe/trunk/test/Analysis/copypaste/blocks.cpp
>     cfe/trunk/test/Analysis/copypaste/false-positives.cpp
>     cfe/trunk/test/Analysis/copypaste/functions.cpp
>     cfe/trunk/test/Analysis/copypaste/objc-methods.m
>     cfe/trunk/test/Analysis/copypaste/sub-sequences.cpp
> Modified:
>     cfe/trunk/include/clang/StaticAnalyzer/Checkers/Checkers.td
>     cfe/trunk/lib/Analysis/CMakeLists.txt
>     cfe/trunk/lib/StaticAnalyzer/Checkers/CMakeLists.txt
>
> Added: cfe/trunk/include/clang/Analysis/CloneDetection.h
> URL:
> http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Analysis/CloneDetection.h?rev=276782&view=auto
>
> ==============================================================================
> --- cfe/trunk/include/clang/Analysis/CloneDetection.h (added)
> +++ cfe/trunk/include/clang/Analysis/CloneDetection.h Tue Jul 26 13:13:12
> 2016
> @@ -0,0 +1,235 @@
> +//===--- CloneDetection.h - Finds code clones in an AST ---------*- C++
> -*-===//
> +//
> +//                     The LLVM Compiler Infrastructure
> +//
> +// This file is distributed under the University of Illinois Open Source
> +// License. See LICENSE.TXT for details.
> +//
>
> +//===----------------------------------------------------------------------===//
> +///
> +/// /file
> +/// This file defines classes for searching and anlyzing source code
> clones.
> +///
>
> +//===----------------------------------------------------------------------===//
> +
> +#ifndef LLVM_CLANG_AST_CLONEDETECTION_H
> +#define LLVM_CLANG_AST_CLONEDETECTION_H
> +
> +#include "clang/Basic/SourceLocation.h"
> +#include "llvm/ADT/StringMap.h"
> +
> +#include <vector>
> +
> +namespace clang {
> +
> +class Stmt;
> +class Decl;
> +class ASTContext;
> +class CompoundStmt;
> +
> +/// \brief Identifies a list of statements.
> +///
> +/// Can either identify a single arbitrary Stmt object, a continuous
> sequence of
> +/// child statements inside a CompoundStmt or no statements at all.
> +class StmtSequence {
> +  /// If this object identifies a sequence of statements inside a
> CompoundStmt,
> +  /// S points to this CompoundStmt. If this object only identifies a
> single
> +  /// Stmt, then S is a pointer to this Stmt.
> +  const Stmt *S;
> +
> +  /// The related ASTContext for S.
> +  ASTContext *Context;
> +
> +  /// If EndIndex is non-zero, then S is a CompoundStmt and this
> StmtSequence
> +  /// instance is representing the CompoundStmt children inside the array
> +  /// [StartIndex, EndIndex).
> +  unsigned StartIndex;
> +  unsigned EndIndex;
> +
> +public:
> +  /// \brief Constructs a StmtSequence holding multiple statements.
> +  ///
> +  /// The resulting StmtSequence identifies a continuous sequence of
> statements
> +  /// in the body of the given CompoundStmt. Which statements of the body
> should
> +  /// be identified needs to be specified by providing a start and end
> index
> +  /// that describe a non-empty sub-array in the body of the given
> CompoundStmt.
> +  ///
> +  /// \param Stmt A CompoundStmt that contains all statements in its body.
> +  /// \param Context The ASTContext for the given CompoundStmt.
> +  /// \param StartIndex The inclusive start index in the children array of
> +  ///                   \p Stmt
> +  /// \param EndIndex The exclusive end index in the children array of \p
> Stmt.
> +  StmtSequence(const CompoundStmt *Stmt, ASTContext &Context,
> +               unsigned StartIndex, unsigned EndIndex);
> +
> +  /// \brief Constructs a StmtSequence holding a single statement.
> +  ///
> +  /// \param Stmt An arbitrary Stmt.
> +  /// \param Context The ASTContext for the given Stmt.
> +  StmtSequence(const Stmt *Stmt, ASTContext &Context);
> +
> +  /// \brief Constructs an empty StmtSequence.
> +  StmtSequence();
> +
> +  typedef const Stmt *const *iterator;
> +
> +  /// Returns an iterator pointing to the first statement in this
> sequence.
> +  iterator begin() const;
> +
> +  /// Returns an iterator pointing behind the last statement in this
> sequence.
> +  iterator end() const;
> +
> +  /// Returns the first statement in this sequence.
> +  ///
> +  /// This method should only be called on a non-empty StmtSequence
> object.
> +  const Stmt *front() const {
> +    assert(!empty());
> +    return begin()[0];
> +  }
> +
> +  /// Returns the last statement in this sequence.
> +  ///
> +  /// This method should only be called on a non-empty StmtSequence
> object.
> +  const Stmt *back() const {
> +    assert(!empty());
> +    return begin()[size() - 1];
> +  }
> +
> +  /// Returns the number of statements this object holds.
> +  unsigned size() const {
> +    if (holdsSequence())
> +      return EndIndex - StartIndex;
> +    if (S == nullptr)
> +      return 0;
> +    return 1;
> +  }
> +
> +  /// Returns true if and only if this StmtSequence contains no
> statements.
> +  bool empty() const { return size() == 0; }
> +
> +  /// Returns the related ASTContext for the stored Stmts.
> +  ASTContext &getASTContext() const {
> +    assert(Context);
> +    return *Context;
> +  }
> +
> +  /// Returns true if this objects holds a list of statements.
> +  bool holdsSequence() const { return EndIndex != 0; }
> +
> +  /// Returns the start sourcelocation of the first statement in this
> sequence.
> +  ///
> +  /// This method should only be called on a non-empty StmtSequence
> object.
> +  SourceLocation getStartLoc() const;
> +
> +  /// Returns the end sourcelocation of the last statement in this
> sequence.
> +  ///
> +  /// This method should only be called on a non-empty StmtSequence
> object.
> +  SourceLocation getEndLoc() const;
> +
> +  bool operator==(const StmtSequence &Other) const {
> +    return std::tie(S, StartIndex, EndIndex) ==
> +           std::tie(Other.S, Other.StartIndex, Other.EndIndex);
> +  }
> +
> +  bool operator!=(const StmtSequence &Other) const {
> +    return std::tie(S, StartIndex, EndIndex) !=
> +           std::tie(Other.S, Other.StartIndex, Other.EndIndex);
> +  }
> +
> +  /// Returns true if and only if this sequence covers a source range that
> +  /// contains the source range of the given sequence \p Other.
> +  ///
> +  /// This method should only be called on a non-empty StmtSequence object
> +  /// and passed a non-empty StmtSequence object.
> +  bool contains(const StmtSequence &Other) const;
> +};
> +
> +/// \brief Searches for clones in source code.
> +///
> +/// First, this class needs a translation unit which is passed via
> +/// \p analyzeTranslationUnit . It will then generate and store search
> data
> +/// for all statements inside the given translation unit.
> +/// Afterwards the generated data can be used to find code clones by
> calling
> +/// \p findClones .
> +///
> +/// This class only searches for clones in exectuable source code
> +/// (e.g. function bodies). Other clones (e.g. cloned comments or
> declarations)
> +/// are not supported.
> +class CloneDetector {
> +public:
> +  /// Holds the data about a StmtSequence that is needed during the
> search for
> +  /// code clones.
> +  struct CloneSignature {
> +    /// \brief Holds all relevant data of a StmtSequence.
> +    ///
> +    /// If this variable is equal for two different StmtSequences, then
> they can
> +    /// be considered clones of each other.
> +    std::vector<unsigned> Data;
> +
> +    /// \brief The complexity of the StmtSequence.
> +    ///
> +    /// This scalar value serves as a simple way of filtering clones that
> are
> +    /// too small to be reported. A greater value indicates that the
> related
> +    /// StmtSequence is probably more interesting to the user.
> +    unsigned Complexity;
> +
> +    /// \brief Creates an empty CloneSignature without any data.
> +    CloneSignature() : Complexity(1) {}
> +
> +    CloneSignature(const std::vector<unsigned> &Data, unsigned Complexity)
> +        : Data(Data), Complexity(Complexity) {}
> +
> +    /// \brief Adds the data from the given CloneSignature to this one.
> +    void add(const CloneSignature &Other) {
> +      Data.insert(Data.end(), Other.Data.begin(), Other.Data.end());
> +      Complexity += Other.Complexity;
> +    }
> +  };
> +
> +  /// Holds group of StmtSequences that are clones of each other and the
> +  /// complexity value (see CloneSignature::Complexity) that all stored
> +  /// StmtSequences have in common.
> +  struct CloneGroup {
> +    std::vector<StmtSequence> Sequences;
> +    unsigned Complexity;
> +
> +    CloneGroup(const StmtSequence &Seq, unsigned Complexity)
> +        : Complexity(Complexity) {
> +      Sequences.push_back(Seq);
> +    }
> +
> +    /// \brief Returns false if and only if this group should be skipped
> when
> +    ///        searching for clones.
> +    bool isValid() const {
> +      // A clone group with only one member makes no sense, so we skip
> them.
> +      return Sequences.size() > 1;
> +    }
> +  };
> +
> +  /// \brief Generates and stores search data for all statements in the
> body of
> +  ///        the given Decl.
> +  void analyzeCodeBody(const Decl *D);
> +
> +  /// \brief Stores the CloneSignature to allow future querying.
> +  void add(const StmtSequence &S, const CloneSignature &Signature);
> +
> +  /// \brief Searches the provided statements for clones.
> +  ///
> +  /// \param Result Output parameter that is filled with a list of found
> +  ///               clone groups. Each group contains multiple
> StmtSequences
> +  ///               that were identified to be clones of each other.
> +  /// \param MinGroupComplexity Only return clones which have at least
> this
> +  ///                           complexity value.
> +  void findClones(std::vector<CloneGroup> &Result, unsigned
> MinGroupComplexity);
> +
> +private:
> +  /// Stores all found clone groups including invalid groups with only a
> single
> +  /// statement.
> +  std::vector<CloneGroup> CloneGroups;
> +  /// Maps search data to its related index in the \p CloneGroups vector.
> +  llvm::StringMap<std::size_t> CloneGroupIndexes;
> +};
> +
> +} // end namespace clang
> +
> +#endif // LLVM_CLANG_AST_CLONEDETECTION_H
>
> Modified: cfe/trunk/include/clang/StaticAnalyzer/Checkers/Checkers.td
> URL:
> http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/StaticAnalyzer/Checkers/Checkers.td?rev=276782&r1=276781&r2=276782&view=diff
>
> ==============================================================================
> --- cfe/trunk/include/clang/StaticAnalyzer/Checkers/Checkers.td (original)
> +++ cfe/trunk/include/clang/StaticAnalyzer/Checkers/Checkers.td Tue Jul 26
> 13:13:12 2016
> @@ -77,6 +77,8 @@ def MPI : Package<"mpi">, InPackage<OptI
>  def LLVM : Package<"llvm">;
>  def Debug : Package<"debug">;
>
> +def CloneDetectionAlpha : Package<"clone">, InPackage<Alpha>, Hidden;
> +
>
>  //===----------------------------------------------------------------------===//
>  // Core Checkers.
>
>  //===----------------------------------------------------------------------===//
> @@ -661,3 +663,17 @@ def BugHashDumper : Checker<"DumpBugHash
>    DescFile<"DebugCheckers.cpp">;
>
>  } // end "debug"
> +
> +
>
> +//===----------------------------------------------------------------------===//
> +// Clone Detection
>
> +//===----------------------------------------------------------------------===//
> +
> +let ParentPackage = CloneDetectionAlpha in {
> +
> +def CloneChecker : Checker<"CloneChecker">,
> +  HelpText<"Reports similar pieces of code.">,
> +  DescFile<"CloneChecker.cpp">;
> +
> +} // end "clone"
> +
>
> Modified: cfe/trunk/lib/Analysis/CMakeLists.txt
> URL:
> http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Analysis/CMakeLists.txt?rev=276782&r1=276781&r2=276782&view=diff
>
> ==============================================================================
> --- cfe/trunk/lib/Analysis/CMakeLists.txt (original)
> +++ cfe/trunk/lib/Analysis/CMakeLists.txt Tue Jul 26 13:13:12 2016
> @@ -9,6 +9,7 @@ add_clang_library(clangAnalysis
>    CFGReachabilityAnalysis.cpp
>    CFGStmtMap.cpp
>    CallGraph.cpp
> +  CloneDetection.cpp
>    CocoaConventions.cpp
>    Consumed.cpp
>    CodeInjector.cpp
>
> Added: cfe/trunk/lib/Analysis/CloneDetection.cpp
> URL:
> http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Analysis/CloneDetection.cpp?rev=276782&view=auto
>
> ==============================================================================
> --- cfe/trunk/lib/Analysis/CloneDetection.cpp (added)
> +++ cfe/trunk/lib/Analysis/CloneDetection.cpp Tue Jul 26 13:13:12 2016
> @@ -0,0 +1,277 @@
> +//===--- CloneDetection.cpp - Finds code clones in an AST -------*- C++
> -*-===//
> +//
> +//                     The LLVM Compiler Infrastructure
> +//
> +// This file is distributed under the University of Illinois Open Source
> +// License. See LICENSE.TXT for details.
> +//
>
> +//===----------------------------------------------------------------------===//
> +///
> +///  This file implements classes for searching and anlyzing source code
> clones.
> +///
>
> +//===----------------------------------------------------------------------===//
> +
> +#include "clang/Analysis/CloneDetection.h"
> +
> +#include "clang/AST/ASTContext.h"
> +#include "clang/AST/RecursiveASTVisitor.h"
> +#include "clang/AST/Stmt.h"
> +#include "llvm/ADT/StringRef.h"
> +
> +using namespace clang;
> +
> +StmtSequence::StmtSequence(const CompoundStmt *Stmt, ASTContext &Context,
> +                           unsigned StartIndex, unsigned EndIndex)
> +    : S(Stmt), Context(&Context), StartIndex(StartIndex),
> EndIndex(EndIndex) {
> +  assert(Stmt && "Stmt must not be a nullptr");
> +  assert(StartIndex < EndIndex && "Given array should not be empty");
> +  assert(EndIndex <= Stmt->size() && "Given array too big for this Stmt");
> +}
> +
> +StmtSequence::StmtSequence(const Stmt *Stmt, ASTContext &Context)
> +    : S(Stmt), Context(&Context), StartIndex(0), EndIndex(0) {}
> +
> +StmtSequence::StmtSequence()
> +    : S(nullptr), Context(nullptr), StartIndex(0), EndIndex(0) {}
> +
> +bool StmtSequence::contains(const StmtSequence &Other) const {
> +  // If both sequences reside in different translation units, they can
> never
> +  // contain each other.
> +  if (Context != Other.Context)
> +    return false;
> +
> +  const SourceManager &SM = Context->getSourceManager();
> +
> +  // Otherwise check if the start and end locations of the current
> sequence
> +  // surround the other sequence.
> +  bool StartIsInBounds =
> +      SM.isBeforeInTranslationUnit(getStartLoc(), Other.getStartLoc()) ||
> +      getStartLoc() == Other.getStartLoc();
> +  if (!StartIsInBounds)
> +    return false;
> +
> +  bool EndIsInBounds =
> +      SM.isBeforeInTranslationUnit(Other.getEndLoc(), getEndLoc()) ||
> +      Other.getEndLoc() == getEndLoc();
> +  return EndIsInBounds;
> +}
> +
> +StmtSequence::iterator StmtSequence::begin() const {
> +  if (!holdsSequence()) {
> +    return &S;
> +  }
> +  auto CS = cast<CompoundStmt>(S);
> +  return CS->body_begin() + StartIndex;
> +}
> +
> +StmtSequence::iterator StmtSequence::end() const {
> +  if (!holdsSequence()) {
> +    return &S + 1;
> +  }
> +  auto CS = cast<CompoundStmt>(S);
> +  return CS->body_begin() + EndIndex;
> +}
> +
> +SourceLocation StmtSequence::getStartLoc() const {
> +  return front()->getLocStart();
> +}
> +
> +SourceLocation StmtSequence::getEndLoc() const { return
> back()->getLocEnd(); }
> +
> +namespace {
> +/// Generates CloneSignatures for a set of statements and stores the
> results in
> +/// a CloneDetector object.
> +class CloneSignatureGenerator {
> +
> +  CloneDetector &CD;
> +  ASTContext &Context;
> +
> +  /// \brief Generates CloneSignatures for all statements in the given
> statement
> +  /// tree and stores them in the CloneDetector.
> +  ///
> +  /// \param S The root of the given statement tree.
> +  /// \return The CloneSignature of the root statement.
> +  CloneDetector::CloneSignature generateSignatures(const Stmt *S) {
> +    // Create an empty signature that will be filled in this method.
> +    CloneDetector::CloneSignature Signature;
> +
> +    // The only relevant data for now is the class of the statement.
> +    // TODO: Collect statement class specific data.
> +    Signature.Data.push_back(S->getStmtClass());
> +
> +    // Storage for the signatures of the direct child statements. This is
> only
> +    // needed if the current statement is a CompoundStmt.
> +    std::vector<CloneDetector::CloneSignature> ChildSignatures;
> +    const CompoundStmt *CS = dyn_cast<const CompoundStmt>(S);
> +
> +    // The signature of a statement includes the signatures of its
> children.
> +    // Therefore we create the signatures for every child and add them to
> the
> +    // current signature.
> +    for (const Stmt *Child : S->children()) {
> +      // Some statements like 'if' can have nullptr children that we will
> skip.
> +      if (!Child)
> +        continue;
> +
> +      // Recursive call to create the signature of the child statement.
> This
> +      // will also create and store all clone groups in this child
> statement.
> +      auto ChildSignature = generateSignatures(Child);
> +
> +      // Add the collected data to the signature of the current statement.
> +      Signature.add(ChildSignature);
> +
> +      // If the current statement is a CompoundStatement, we need to
> store the
> +      // signature for the generation of the sub-sequences.
> +      if (CS)
> +        ChildSignatures.push_back(ChildSignature);
> +    }
> +
> +    // If the current statement is a CompoundStmt, we also need to create
> the
> +    // clone groups from the sub-sequences inside the children.
> +    if (CS)
> +      handleSubSequences(CS, ChildSignatures);
> +
> +    // Save the signature for the current statement in the CloneDetector
> object.
> +    CD.add(StmtSequence(S, Context), Signature);
> +
> +    return Signature;
> +  }
> +
> +  /// \brief Adds all possible sub-sequences in the child array of the
> given
> +  ///        CompoundStmt to the CloneDetector.
> +  /// \param CS The given CompoundStmt.
> +  /// \param ChildSignatures A list of calculated signatures for each
> child in
> +  ///                        the given CompoundStmt.
> +  void handleSubSequences(
> +      const CompoundStmt *CS,
> +      const std::vector<CloneDetector::CloneSignature> &ChildSignatures) {
> +
> +    // FIXME: This function has quadratic runtime right now. Check if
> skipping
> +    // this function for too long CompoundStmts is an option.
> +
> +    // The length of the sub-sequence. We don't need to handle sequences
> with
> +    // the length 1 as they are already handled in CollectData().
> +    for (unsigned Length = 2; Length <= CS->size(); ++Length) {
> +      // The start index in the body of the CompoundStmt. We increase the
> +      // position until the end of the sub-sequence reaches the end of the
> +      // CompoundStmt body.
> +      for (unsigned Pos = 0; Pos <= CS->size() - Length; ++Pos) {
> +        // Create an empty signature and add the signatures of all
> selected
> +        // child statements to it.
> +        CloneDetector::CloneSignature SubSignature;
> +
> +        for (unsigned i = Pos; i < Pos + Length; ++i) {
> +          SubSignature.add(ChildSignatures[i]);
> +        }
> +
> +        // Save the signature together with the information about what
> children
> +        // sequence we selected.
> +        CD.add(StmtSequence(CS, Context, Pos, Pos + Length),
> SubSignature);
> +      }
> +    }
> +  }
> +
> +public:
> +  explicit CloneSignatureGenerator(CloneDetector &CD, ASTContext &Context)
> +      : CD(CD), Context(Context) {}
> +
> +  /// \brief Generates signatures for all statements in the given
> function body.
> +  void consumeCodeBody(const Stmt *S) { generateSignatures(S); }
> +};
> +} // end anonymous namespace
> +
> +void CloneDetector::analyzeCodeBody(const Decl *D) {
> +  assert(D);
> +  assert(D->hasBody());
> +  CloneSignatureGenerator Generator(*this, D->getASTContext());
> +  Generator.consumeCodeBody(D->getBody());
> +}
> +
> +void CloneDetector::add(const StmtSequence &S,
> +                        const CloneSignature &Signature) {
> +  // StringMap only works with StringRefs, so we create one for our data
> vector.
> +  auto &Data = Signature.Data;
> +  StringRef DataRef = StringRef(reinterpret_cast<const char
> *>(Data.data()),
> +                                Data.size() * sizeof(unsigned));
> +
> +  // Search with the help of the signature if we already have encountered
> a
> +  // clone of the given StmtSequence.
> +  auto I = CloneGroupIndexes.find(DataRef);
> +  if (I == CloneGroupIndexes.end()) {
> +    // We haven't found an existing clone group, so we create a new clone
> group
> +    // for this StmtSequence and store the index of it in our search map.
> +    CloneGroupIndexes[DataRef] = CloneGroups.size();
> +    CloneGroups.emplace_back(S, Signature.Complexity);
> +    return;
> +  }
> +
> +  // We have found an existing clone group and can expand it with the
> given
> +  // StmtSequence.
> +  CloneGroups[I->getValue()].Sequences.push_back(S);
> +}
> +
> +namespace {
> +/// \brief Returns true if and only if \p Stmt contains at least one other
> +/// sequence in the \p Group.
> +bool containsAnyInGroup(StmtSequence &Stmt,
> +                            CloneDetector::CloneGroup &Group) {
> +  for (StmtSequence &GroupStmt : Group.Sequences) {
> +    if (Stmt.contains(GroupStmt))
> +      return true;
> +  }
> +  return false;
> +}
> +
> +/// \brief Returns true if and only if all sequences in \p OtherGroup are
> +/// contained by a sequence in \p Group.
> +bool containsGroup(CloneDetector::CloneGroup &Group,
> +                   CloneDetector::CloneGroup &OtherGroup) {
> +  // We have less sequences in the current group than we have in the
> other,
> +  // so we will never fulfill the requirement for returning true. This is
> only
> +  // possible because we know that a sequence in Group can contain at most
> +  // one sequence in OtherGroup.
> +  if (Group.Sequences.size() < OtherGroup.Sequences.size())
> +    return false;
> +
> +  for (StmtSequence &Stmt : Group.Sequences) {
> +    if (!containsAnyInGroup(Stmt, OtherGroup))
> +      return false;
> +  }
> +  return true;
> +}
> +} // end anonymous namespace
> +
> +void CloneDetector::findClones(std::vector<CloneGroup> &Result,
> +                               unsigned MinGroupComplexity) {
> +  // Add every valid clone group that fulfills the complexity requirement.
> +  for (const CloneGroup &Group : CloneGroups) {
> +    if (Group.isValid() && Group.Complexity >= MinGroupComplexity) {
> +      Result.push_back(Group);
> +    }
> +  }
> +
> +  std::vector<unsigned> IndexesToRemove;
> +
> +  // Compare every group in the result with the rest. If one groups
> contains
> +  // another group, we only need to return the bigger group.
> +  // Note: This doesn't scale well, so if possible avoid calling any heavy
> +  // function from this loop to minimize the performance impact.
> +  for (unsigned i = 0; i < Result.size(); ++i) {
> +    for (unsigned j = 0; j < Result.size(); ++j) {
> +      // Don't compare a group with itself.
> +      if (i == j)
> +        continue;
> +
> +      if (containsGroup(Result[j], Result[i])) {
> +        IndexesToRemove.push_back(i);
> +        break;
> +      }
> +    }
> +  }
> +
> +  // Erasing a list of indexes from the vector should be done with
> decreasing
> +  // indexes. As IndexesToRemove is constructed with increasing values,
> we just
> +  // reverse iterate over it to get the desired order.
> +  for (auto I = IndexesToRemove.rbegin(); I != IndexesToRemove.rend();
> ++I) {
> +    Result.erase(Result.begin() + *I);
> +  }
> +}
>
> Modified: cfe/trunk/lib/StaticAnalyzer/Checkers/CMakeLists.txt
> URL:
> http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/StaticAnalyzer/Checkers/CMakeLists.txt?rev=276782&r1=276781&r2=276782&view=diff
>
> ==============================================================================
> --- cfe/trunk/lib/StaticAnalyzer/Checkers/CMakeLists.txt (original)
> +++ cfe/trunk/lib/StaticAnalyzer/Checkers/CMakeLists.txt Tue Jul 26
> 13:13:12 2016
> @@ -22,6 +22,7 @@ add_clang_library(clangStaticAnalyzerChe
>    CheckerDocumentation.cpp
>    ChrootChecker.cpp
>    ClangCheckers.cpp
> +  CloneChecker.cpp
>    CXXSelfAssignmentChecker.cpp
>    DeadStoresChecker.cpp
>    DebugCheckers.cpp
>
> Added: cfe/trunk/lib/StaticAnalyzer/Checkers/CloneChecker.cpp
> URL:
> http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/StaticAnalyzer/Checkers/CloneChecker.cpp?rev=276782&view=auto
>
> ==============================================================================
> --- cfe/trunk/lib/StaticAnalyzer/Checkers/CloneChecker.cpp (added)
> +++ cfe/trunk/lib/StaticAnalyzer/Checkers/CloneChecker.cpp Tue Jul 26
> 13:13:12 2016
> @@ -0,0 +1,96 @@
> +//===--- CloneChecker.cpp - Clone detection checker -------------*- C++
> -*-===//
> +//
> +//                     The LLVM Compiler Infrastructure
> +//
> +// This file is distributed under the University of Illinois Open Source
> +// License. See LICENSE.TXT for details.
> +//
>
> +//===----------------------------------------------------------------------===//
> +///
> +/// \file
> +/// CloneChecker is a checker that reports clones in the current
> translation
> +/// unit.
> +///
>
> +//===----------------------------------------------------------------------===//
> +
> +#include "ClangSACheckers.h"
> +#include "clang/Analysis/CloneDetection.h"
> +#include "clang/Basic/Diagnostic.h"
> +#include "clang/StaticAnalyzer/Core/Checker.h"
> +#include "clang/StaticAnalyzer/Core/CheckerManager.h"
> +#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
> +
> +using namespace clang;
> +using namespace ento;
> +
> +namespace {
> +class CloneChecker
> +    : public Checker<check::ASTCodeBody, check::EndOfTranslationUnit> {
> +  mutable CloneDetector CloneDetector;
> +
> +public:
> +  void checkASTCodeBody(const Decl *D, AnalysisManager &Mgr,
> +                        BugReporter &BR) const;
> +
> +  void checkEndOfTranslationUnit(const TranslationUnitDecl *TU,
> +                                 AnalysisManager &Mgr, BugReporter &BR)
> const;
> +};
> +} // end anonymous namespace
> +
> +void CloneChecker::checkASTCodeBody(const Decl *D, AnalysisManager &Mgr,
> +                                    BugReporter &BR) const {
> +  // Every statement that should be included in the search for clones
> needs to
> +  // be passed to the CloneDetector.
> +  CloneDetector.analyzeCodeBody(D);
> +}
> +
> +void CloneChecker::checkEndOfTranslationUnit(const TranslationUnitDecl
> *TU,
> +                                             AnalysisManager &Mgr,
> +                                             BugReporter &BR) const {
> +  // At this point, every statement in the translation unit has been
> analyzed by
> +  // the CloneDetector. The only thing left to do is to report the found
> clones.
> +
> +  int MinComplexity = Mgr.getAnalyzerOptions().getOptionAsInteger(
> +      "MinimumCloneComplexity", 10, this);
> +
> +  assert(MinComplexity >= 0);
> +
> +  SourceManager &SM = BR.getSourceManager();
> +
> +  std::vector<CloneDetector::CloneGroup> CloneGroups;
> +  CloneDetector.findClones(CloneGroups, MinComplexity);
> +
> +  DiagnosticsEngine &DiagEngine = Mgr.getDiagnostic();
> +
> +  unsigned WarnID = DiagEngine.getCustomDiagID(DiagnosticsEngine::Warning,
> +                                               "Detected code clone.");
> +
> +  unsigned NoteID = DiagEngine.getCustomDiagID(DiagnosticsEngine::Note,
> +                                               "Related code clone is
> here.");
> +
> +  for (CloneDetector::CloneGroup &Group : CloneGroups) {
> +    // For readability reasons we sort the clones by line numbers.
> +    std::sort(Group.Sequences.begin(), Group.Sequences.end(),
> +              [&SM](const StmtSequence &LHS, const StmtSequence &RHS) {
> +                return SM.isBeforeInTranslationUnit(LHS.getStartLoc(),
> +                                                    RHS.getStartLoc()) &&
> +                       SM.isBeforeInTranslationUnit(LHS.getEndLoc(),
> +                                                    RHS.getEndLoc());
> +              });
> +
> +    // We group the clones by printing the first as a warning and all
> others
> +    // as a note.
> +    DiagEngine.Report(Group.Sequences.front().getStartLoc(), WarnID);
> +    for (unsigned i = 1; i < Group.Sequences.size(); ++i) {
> +      DiagEngine.Report(Group.Sequences[i].getStartLoc(), NoteID);
> +    }
> +  }
> +}
> +
>
> +//===----------------------------------------------------------------------===//
> +// Register CloneChecker
>
> +//===----------------------------------------------------------------------===//
> +
> +void ento::registerCloneChecker(CheckerManager &Mgr) {
> +  Mgr.registerChecker<CloneChecker>();
> +}
>
> Added: cfe/trunk/test/Analysis/copypaste/blocks.cpp
> URL:
> http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Analysis/copypaste/blocks.cpp?rev=276782&view=auto
>
> ==============================================================================
> --- cfe/trunk/test/Analysis/copypaste/blocks.cpp (added)
> +++ cfe/trunk/test/Analysis/copypaste/blocks.cpp Tue Jul 26 13:13:12 2016
> @@ -0,0 +1,19 @@
> +// RUN: %clang_cc1 -analyze -fblocks -std=c++11
> -analyzer-checker=alpha.clone.CloneChecker -verify %s
> +
> +// This tests if we search for clones in blocks.
> +
> +void log();
> +
> +auto BlockA = ^(int a, int b){ // expected-warning{{Detected code clone.}}
> +  log();
> +  if (a > b)
> +    return a;
> +  return b;
> +};
> +
> +auto BlockB = ^(int a, int b){ // expected-note{{Related code clone is
> here.}}
> +  log();
> +  if (a > b)
> +    return a;
> +  return b;
> +};
>
> Added: cfe/trunk/test/Analysis/copypaste/false-positives.cpp
> URL:
> http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Analysis/copypaste/false-positives.cpp?rev=276782&view=auto
>
> ==============================================================================
> --- cfe/trunk/test/Analysis/copypaste/false-positives.cpp (added)
> +++ cfe/trunk/test/Analysis/copypaste/false-positives.cpp Tue Jul 26
> 13:13:12 2016
> @@ -0,0 +1,29 @@
> +// RUN: %clang_cc1 -analyze -std=c++11
> -analyzer-checker=alpha.clone.CloneChecker -verify %s
> +
> +// This test contains false-positive reports from the CloneChecker that
> need to
> +// be fixed.
> +
> +void log();
> +
> +int max(int a, int b) { // expected-warning{{Detected code clone.}}
> +  log();
> +  if (a > b)
> +    return a;
> +  return b;
> +}
> +
> +// FIXME: Detect different binary operator kinds.
> +int min1(int a, int b) { // expected-note{{Related code clone is here.}}
> +  log();
> +  if (a < b)
> +    return a;
> +  return b;
> +}
> +
> +// FIXME: Detect different variable patterns.
> +int min2(int a, int b) { // expected-note{{Related code clone is here.}}
> +  log();
> +  if (b > a)
> +    return a;
> +  return b;
> +}
>
> Added: cfe/trunk/test/Analysis/copypaste/functions.cpp
> URL:
> http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Analysis/copypaste/functions.cpp?rev=276782&view=auto
>
> ==============================================================================
> --- cfe/trunk/test/Analysis/copypaste/functions.cpp (added)
> +++ cfe/trunk/test/Analysis/copypaste/functions.cpp Tue Jul 26 13:13:12
> 2016
> @@ -0,0 +1,25 @@
> +// RUN: %clang_cc1 -analyze -std=c++11
> -analyzer-checker=alpha.clone.CloneChecker -verify %s
> +
> +// This tests if we search for clones in functions.
> +
> +void log();
> +
> +int max(int a, int b) { // expected-warning{{Detected code clone.}}
> +  log();
> +  if (a > b)
> +    return a;
> +  return b;
> +}
> +
> +int maxClone(int x, int y) { // expected-note{{Related code clone is
> here.}}
> +  log();
> +  if (x > y)
> +    return x;
> +  return y;
> +}
> +
> +// Functions below are not clones and should not be reported.
> +
> +int foo(int a, int b) { // no-warning
> +  return a + b;
> +}
>
> Added: cfe/trunk/test/Analysis/copypaste/objc-methods.m
> URL:
> http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Analysis/copypaste/objc-methods.m?rev=276782&view=auto
>
> ==============================================================================
> --- cfe/trunk/test/Analysis/copypaste/objc-methods.m (added)
> +++ cfe/trunk/test/Analysis/copypaste/objc-methods.m Tue Jul 26 13:13:12
> 2016
> @@ -0,0 +1,27 @@
> +// RUN: %clang_cc1 -analyze -Wno-objc-root-class
> -analyzer-checker=alpha.clone.CloneChecker -verify %s
> +
> +// This tests if we search for clones in Objective-C methods.
> +
> + at interface A
> +- (int) setOk : (int) a : (int) b;
> + at end
> +
> + at implementation A
> +- (int) setOk : (int) a : (int) b {  // expected-warning{{Detected code
> clone.}}
> +  if (a > b)
> +    return a;
> +  return b;
> +}
> + at end
> +
> + at interface B
> +- (int) setOk : (int) a : (int) b;
> + at end
> +
> + at implementation B
> +- (int) setOk : (int) a : (int) b { // expected-note{{Related code clone
> is here.}}
> +  if (a > b)
> +    return a;
> +  return b;
> +}
> + at end
>
> Added: cfe/trunk/test/Analysis/copypaste/sub-sequences.cpp
> URL:
> http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Analysis/copypaste/sub-sequences.cpp?rev=276782&view=auto
>
> ==============================================================================
> --- cfe/trunk/test/Analysis/copypaste/sub-sequences.cpp (added)
> +++ cfe/trunk/test/Analysis/copypaste/sub-sequences.cpp Tue Jul 26
> 13:13:12 2016
> @@ -0,0 +1,27 @@
> +// RUN: %clang_cc1 -analyze -std=c++11
> -analyzer-checker=alpha.clone.CloneChecker -verify %s
> +
> +// This tests if sub-sequences can match with normal sequences.
> +
> +void log2(int a);
> +void log();
> +
> +int max(int a, int b) {
> +  log2(a);
> +  log(); // expected-warning{{Detected code clone.}}
> +  if (a > b)
> +    return a;
> +  return b;
> +}
> +
> +int maxClone(int a, int b) {
> +  log(); // expected-note{{Related code clone is here.}}
> +  if (a > b)
> +    return a;
> +  return b;
> +}
> +
> +// Functions below are not clones and should not be reported.
> +
> +int foo(int a, int b) { // no-warning
> +  return a + b;
> +}
>
>
> _______________________________________________
> cfe-commits mailing list
> cfe-commits at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
>
-- 
Mike
Sent from phone
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