Use the space freed up by sparc and zaurus to import LLVM.

ok hackroom@

1 files changed, 595 insertions, 0 deletions

diff --git a/gnu/llvm/tools/clang/unittests/Tooling/RefactoringTest.cpp b/gnu/llvm/tools/clang/unittests/Tooling/RefactoringTest.cpp
new file mode 100644
index 00000000000..ff11aeae117
--- /dev/null
+++ b/gnu/llvm/tools/clang/unittests/Tooling/RefactoringTest.cpp
@@ -0,0 +1,595 @@
+//===- unittest/Tooling/RefactoringTest.cpp - Refactoring unit tests ------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "RewriterTestContext.h"
+#include "clang/AST/ASTConsumer.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/DeclCXX.h"
+#include "clang/AST/DeclGroup.h"
+#include "clang/AST/RecursiveASTVisitor.h"
+#include "clang/Basic/Diagnostic.h"
+#include "clang/Basic/DiagnosticOptions.h"
+#include "clang/Basic/FileManager.h"
+#include "clang/Basic/LangOptions.h"
+#include "clang/Basic/SourceManager.h"
+#include "clang/Frontend/CompilerInstance.h"
+#include "clang/Frontend/FrontendAction.h"
+#include "clang/Frontend/TextDiagnosticPrinter.h"
+#include "clang/Rewrite/Core/Rewriter.h"
+#include "clang/Tooling/Refactoring.h"
+#include "clang/Tooling/Tooling.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/Support/Path.h"
+#include "gtest/gtest.h"
+
+namespace clang {
+namespace tooling {
+
+class ReplacementTest : public ::testing::Test {
+ protected:
+  Replacement createReplacement(SourceLocation Start, unsigned Length,
+                                llvm::StringRef ReplacementText) {
+    return Replacement(Context.Sources, Start, Length, ReplacementText);
+  }
+
+  RewriterTestContext Context;
+};
+
+TEST_F(ReplacementTest, CanDeleteAllText) {
+  FileID ID = Context.createInMemoryFile("input.cpp", "text");
+  SourceLocation Location = Context.getLocation(ID, 1, 1);
+  Replacement Replace(createReplacement(Location, 4, ""));
+  EXPECT_TRUE(Replace.apply(Context.Rewrite));
+  EXPECT_EQ("", Context.getRewrittenText(ID));
+}
+
+TEST_F(ReplacementTest, CanDeleteAllTextInTextWithNewlines) {
+  FileID ID = Context.createInMemoryFile("input.cpp", "line1\nline2\nline3");
+  SourceLocation Location = Context.getLocation(ID, 1, 1);
+  Replacement Replace(createReplacement(Location, 17, ""));
+  EXPECT_TRUE(Replace.apply(Context.Rewrite));
+  EXPECT_EQ("", Context.getRewrittenText(ID));
+}
+
+TEST_F(ReplacementTest, CanAddText) {
+  FileID ID = Context.createInMemoryFile("input.cpp", "");
+  SourceLocation Location = Context.getLocation(ID, 1, 1);
+  Replacement Replace(createReplacement(Location, 0, "result"));
+  EXPECT_TRUE(Replace.apply(Context.Rewrite));
+  EXPECT_EQ("result", Context.getRewrittenText(ID));
+}
+
+TEST_F(ReplacementTest, CanReplaceTextAtPosition) {
+  FileID ID = Context.createInMemoryFile("input.cpp",
+                                         "line1\nline2\nline3\nline4");
+  SourceLocation Location = Context.getLocation(ID, 2, 3);
+  Replacement Replace(createReplacement(Location, 12, "x"));
+  EXPECT_TRUE(Replace.apply(Context.Rewrite));
+  EXPECT_EQ("line1\nlixne4", Context.getRewrittenText(ID));
+}
+
+TEST_F(ReplacementTest, CanReplaceTextAtPositionMultipleTimes) {
+  FileID ID = Context.createInMemoryFile("input.cpp",
+                                         "line1\nline2\nline3\nline4");
+  SourceLocation Location1 = Context.getLocation(ID, 2, 3);
+  Replacement Replace1(createReplacement(Location1, 12, "x\ny\n"));
+  EXPECT_TRUE(Replace1.apply(Context.Rewrite));
+  EXPECT_EQ("line1\nlix\ny\nne4", Context.getRewrittenText(ID));
+
+  // Since the original source has not been modified, the (4, 4) points to the
+  // 'e' in the original content.
+  SourceLocation Location2 = Context.getLocation(ID, 4, 4);
+  Replacement Replace2(createReplacement(Location2, 1, "f"));
+  EXPECT_TRUE(Replace2.apply(Context.Rewrite));
+  EXPECT_EQ("line1\nlix\ny\nnf4", Context.getRewrittenText(ID));
+}
+
+TEST_F(ReplacementTest, ApplyFailsForNonExistentLocation) {
+  Replacement Replace("nonexistent-file.cpp", 0, 1, "");
+  EXPECT_FALSE(Replace.apply(Context.Rewrite));
+}
+
+TEST_F(ReplacementTest, CanRetrivePath) {
+  Replacement Replace("/path/to/file.cpp", 0, 1, "");
+  EXPECT_EQ("/path/to/file.cpp", Replace.getFilePath());
+}
+
+TEST_F(ReplacementTest, ReturnsInvalidPath) {
+  Replacement Replace1(Context.Sources, SourceLocation(), 0, "");
+  EXPECT_TRUE(Replace1.getFilePath().empty());
+
+  Replacement Replace2;
+  EXPECT_TRUE(Replace2.getFilePath().empty());
+}
+
+TEST_F(ReplacementTest, CanApplyReplacements) {
+  FileID ID = Context.createInMemoryFile("input.cpp",
+                                         "line1\nline2\nline3\nline4");
+  Replacements Replaces;
+  Replaces.insert(Replacement(Context.Sources, Context.getLocation(ID, 2, 1),
+                              5, "replaced"));
+  Replaces.insert(Replacement(Context.Sources, Context.getLocation(ID, 3, 1),
+                              5, "other"));
+  EXPECT_TRUE(applyAllReplacements(Replaces, Context.Rewrite));
+  EXPECT_EQ("line1\nreplaced\nother\nline4", Context.getRewrittenText(ID));
+}
+
+// FIXME: Remove this test case when Replacements is implemented as std::vector
+// instead of std::set. The other ReplacementTest tests will need to be updated
+// at that point as well.
+TEST_F(ReplacementTest, VectorCanApplyReplacements) {
+  FileID ID = Context.createInMemoryFile("input.cpp",
+                                         "line1\nline2\nline3\nline4");
+  std::vector<Replacement> Replaces;
+  Replaces.push_back(Replacement(Context.Sources, Context.getLocation(ID, 2, 1),
+                                 5, "replaced"));
+  Replaces.push_back(
+      Replacement(Context.Sources, Context.getLocation(ID, 3, 1), 5, "other"));
+  EXPECT_TRUE(applyAllReplacements(Replaces, Context.Rewrite));
+  EXPECT_EQ("line1\nreplaced\nother\nline4", Context.getRewrittenText(ID));
+}
+
+TEST_F(ReplacementTest, SkipsDuplicateReplacements) {
+  FileID ID = Context.createInMemoryFile("input.cpp",
+                                         "line1\nline2\nline3\nline4");
+  Replacements Replaces;
+  Replaces.insert(Replacement(Context.Sources, Context.getLocation(ID, 2, 1),
+                              5, "replaced"));
+  Replaces.insert(Replacement(Context.Sources, Context.getLocation(ID, 2, 1),
+                              5, "replaced"));
+  Replaces.insert(Replacement(Context.Sources, Context.getLocation(ID, 2, 1),
+                              5, "replaced"));
+  EXPECT_TRUE(applyAllReplacements(Replaces, Context.Rewrite));
+  EXPECT_EQ("line1\nreplaced\nline3\nline4", Context.getRewrittenText(ID));
+}
+
+TEST_F(ReplacementTest, ApplyAllFailsIfOneApplyFails) {
+  // This test depends on the value of the file name of an invalid source
+  // location being in the range ]a, z[.
+  FileID IDa = Context.createInMemoryFile("a.cpp", "text");
+  FileID IDz = Context.createInMemoryFile("z.cpp", "text");
+  Replacements Replaces;
+  Replaces.insert(Replacement(Context.Sources, Context.getLocation(IDa, 1, 1),
+                              4, "a"));
+  Replaces.insert(Replacement(Context.Sources, SourceLocation(),
+                              5, "2"));
+  Replaces.insert(Replacement(Context.Sources, Context.getLocation(IDz, 1, 1),
+                              4, "z"));
+  EXPECT_FALSE(applyAllReplacements(Replaces, Context.Rewrite));
+  EXPECT_EQ("a", Context.getRewrittenText(IDa));
+  EXPECT_EQ("z", Context.getRewrittenText(IDz));
+}
+
+TEST(ShiftedCodePositionTest, FindsNewCodePosition) {
+  Replacements Replaces;
+  Replaces.insert(Replacement("", 0, 1, ""));
+  Replaces.insert(Replacement("", 4, 3, " "));
+  // Assume ' int   i;' is turned into 'int i;' and cursor is located at '|'.
+  EXPECT_EQ(0u, shiftedCodePosition(Replaces, 0)); // |int   i;
+  EXPECT_EQ(0u, shiftedCodePosition(Replaces, 1)); //  |nt   i;
+  EXPECT_EQ(1u, shiftedCodePosition(Replaces, 2)); //  i|t   i;
+  EXPECT_EQ(2u, shiftedCodePosition(Replaces, 3)); //  in|   i;
+  EXPECT_EQ(3u, shiftedCodePosition(Replaces, 4)); //  int|  i;
+  EXPECT_EQ(3u, shiftedCodePosition(Replaces, 5)); //  int | i;
+  EXPECT_EQ(3u, shiftedCodePosition(Replaces, 6)); //  int  |i;
+  EXPECT_EQ(4u, shiftedCodePosition(Replaces, 7)); //  int   |;
+  EXPECT_EQ(5u, shiftedCodePosition(Replaces, 8)); //  int   i|
+}
+
+// FIXME: Remove this test case when Replacements is implemented as std::vector
+// instead of std::set. The other ReplacementTest tests will need to be updated
+// at that point as well.
+TEST(ShiftedCodePositionTest, VectorFindsNewCodePositionWithInserts) {
+  std::vector<Replacement> Replaces;
+  Replaces.push_back(Replacement("", 0, 1, ""));
+  Replaces.push_back(Replacement("", 4, 3, " "));
+  // Assume ' int   i;' is turned into 'int i;' and cursor is located at '|'.
+  EXPECT_EQ(0u, shiftedCodePosition(Replaces, 0)); // |int   i;
+  EXPECT_EQ(0u, shiftedCodePosition(Replaces, 1)); //  |nt   i;
+  EXPECT_EQ(1u, shiftedCodePosition(Replaces, 2)); //  i|t   i;
+  EXPECT_EQ(2u, shiftedCodePosition(Replaces, 3)); //  in|   i;
+  EXPECT_EQ(3u, shiftedCodePosition(Replaces, 4)); //  int|  i;
+  EXPECT_EQ(3u, shiftedCodePosition(Replaces, 5)); //  int | i;
+  EXPECT_EQ(3u, shiftedCodePosition(Replaces, 6)); //  int  |i;
+  EXPECT_EQ(4u, shiftedCodePosition(Replaces, 7)); //  int   |;
+  EXPECT_EQ(5u, shiftedCodePosition(Replaces, 8)); //  int   i|
+}
+
+TEST(ShiftedCodePositionTest, FindsNewCodePositionWithInserts) {
+  Replacements Replaces;
+  Replaces.insert(Replacement("", 4, 0, "\"\n\""));
+  // Assume '"12345678"' is turned into '"1234"\n"5678"'.
+  EXPECT_EQ(3u, shiftedCodePosition(Replaces, 3)); // "123|5678"
+  EXPECT_EQ(7u, shiftedCodePosition(Replaces, 4)); // "1234|678"
+  EXPECT_EQ(8u, shiftedCodePosition(Replaces, 5)); // "12345|78"
+}
+
+TEST(ShiftedCodePositionTest, FindsNewCodePositionInReplacedText) {
+  Replacements Replaces;
+  // Replace the first four characters with "abcd".
+  Replaces.insert(Replacement("", 0, 4, "abcd"));
+  for (unsigned i = 0; i < 3; ++i)
+    EXPECT_EQ(i, shiftedCodePosition(Replaces, i));
+}
+
+class FlushRewrittenFilesTest : public ::testing::Test {
+public:
+   FlushRewrittenFilesTest() {}
+
+   ~FlushRewrittenFilesTest() override {
+    for (llvm::StringMap<std::string>::iterator I = TemporaryFiles.begin(),
+                                                E = TemporaryFiles.end();
+         I != E; ++I) {
+      llvm::StringRef Name = I->second;
+      std::error_code EC = llvm::sys::fs::remove(Name);
+      (void)EC;
+      assert(!EC);
+    }
+  }
+
+  FileID createFile(llvm::StringRef Name, llvm::StringRef Content) {
+    SmallString<1024> Path;
+    int FD;
+    std::error_code EC = llvm::sys::fs::createTemporaryFile(Name, "", FD, Path);
+    assert(!EC);
+    (void)EC;
+
+    llvm::raw_fd_ostream OutStream(FD, true);
+    OutStream << Content;
+    OutStream.close();
+    const FileEntry *File = Context.Files.getFile(Path);
+    assert(File != nullptr);
+
+    StringRef Found =
+        TemporaryFiles.insert(std::make_pair(Name, Path.str())).first->second;
+    assert(Found == Path);
+    (void)Found;
+    return Context.Sources.createFileID(File, SourceLocation(), SrcMgr::C_User);
+  }
+
+  std::string getFileContentFromDisk(llvm::StringRef Name) {
+    std::string Path = TemporaryFiles.lookup(Name);
+    assert(!Path.empty());
+    // We need to read directly from the FileManager without relaying through
+    // a FileEntry, as otherwise we'd read through an already opened file
+    // descriptor, which might not see the changes made.
+    // FIXME: Figure out whether there is a way to get the SourceManger to
+    // reopen the file.
+    auto FileBuffer = Context.Files.getBufferForFile(Path);
+    return (*FileBuffer)->getBuffer();
+  }
+
+  llvm::StringMap<std::string> TemporaryFiles;
+  RewriterTestContext Context;
+};
+
+TEST_F(FlushRewrittenFilesTest, StoresChangesOnDisk) {
+  FileID ID = createFile("input.cpp", "line1\nline2\nline3\nline4");
+  Replacements Replaces;
+  Replaces.insert(Replacement(Context.Sources, Context.getLocation(ID, 2, 1),
+                              5, "replaced"));
+  EXPECT_TRUE(applyAllReplacements(Replaces, Context.Rewrite));
+  EXPECT_FALSE(Context.Rewrite.overwriteChangedFiles());
+  EXPECT_EQ("line1\nreplaced\nline3\nline4",
+            getFileContentFromDisk("input.cpp"));
+}
+
+namespace {
+template <typename T>
+class TestVisitor : public clang::RecursiveASTVisitor<T> {
+public:
+  bool runOver(StringRef Code) {
+    return runToolOnCode(new TestAction(this), Code);
+  }
+
+protected:
+  clang::SourceManager *SM;
+  clang::ASTContext *Context;
+
+private:
+  class FindConsumer : public clang::ASTConsumer {
+  public:
+    FindConsumer(TestVisitor *Visitor) : Visitor(Visitor) {}
+
+    void HandleTranslationUnit(clang::ASTContext &Context) override {
+      Visitor->TraverseDecl(Context.getTranslationUnitDecl());
+    }
+
+  private:
+    TestVisitor *Visitor;
+  };
+
+  class TestAction : public clang::ASTFrontendAction {
+  public:
+    TestAction(TestVisitor *Visitor) : Visitor(Visitor) {}
+
+    std::unique_ptr<clang::ASTConsumer>
+    CreateASTConsumer(clang::CompilerInstance &compiler,
+                      llvm::StringRef dummy) override {
+      Visitor->SM = &compiler.getSourceManager();
+      Visitor->Context = &compiler.getASTContext();
+      /// TestConsumer will be deleted by the framework calling us.
+      return llvm::make_unique<FindConsumer>(Visitor);
+    }
+
+  private:
+    TestVisitor *Visitor;
+  };
+};
+} // end namespace
+
+void expectReplacementAt(const Replacement &Replace,
+                         StringRef File, unsigned Offset, unsigned Length) {
+  ASSERT_TRUE(Replace.isApplicable());
+  EXPECT_EQ(File, Replace.getFilePath());
+  EXPECT_EQ(Offset, Replace.getOffset());
+  EXPECT_EQ(Length, Replace.getLength());
+}
+
+class ClassDeclXVisitor : public TestVisitor<ClassDeclXVisitor> {
+public:
+  bool VisitCXXRecordDecl(CXXRecordDecl *Record) {
+    if (Record->getName() == "X") {
+      Replace = Replacement(*SM, Record, "");
+    }
+    return true;
+  }
+  Replacement Replace;
+};
+
+TEST(Replacement, CanBeConstructedFromNode) {
+  ClassDeclXVisitor ClassDeclX;
+  EXPECT_TRUE(ClassDeclX.runOver("     class X;"));
+  expectReplacementAt(ClassDeclX.Replace, "input.cc", 5, 7);
+}
+
+TEST(Replacement, ReplacesAtSpellingLocation) {
+  ClassDeclXVisitor ClassDeclX;
+  EXPECT_TRUE(ClassDeclX.runOver("#define A(Y) Y\nA(class X);"));
+  expectReplacementAt(ClassDeclX.Replace, "input.cc", 17, 7);
+}
+
+class CallToFVisitor : public TestVisitor<CallToFVisitor> {
+public:
+  bool VisitCallExpr(CallExpr *Call) {
+    if (Call->getDirectCallee()->getName() == "F") {
+      Replace = Replacement(*SM, Call, "");
+    }
+    return true;
+  }
+  Replacement Replace;
+};
+
+TEST(Replacement, FunctionCall) {
+  CallToFVisitor CallToF;
+  EXPECT_TRUE(CallToF.runOver("void F(); void G() { F(); }"));
+  expectReplacementAt(CallToF.Replace, "input.cc", 21, 3);
+}
+
+TEST(Replacement, TemplatedFunctionCall) {
+  CallToFVisitor CallToF;
+  EXPECT_TRUE(CallToF.runOver(
+        "template <typename T> void F(); void G() { F<int>(); }"));
+  expectReplacementAt(CallToF.Replace, "input.cc", 43, 8);
+}
+
+class NestedNameSpecifierAVisitor
+    : public TestVisitor<NestedNameSpecifierAVisitor> {
+public:
+  bool TraverseNestedNameSpecifierLoc(NestedNameSpecifierLoc NNSLoc) {
+    if (NNSLoc.getNestedNameSpecifier()) {
+      if (const NamespaceDecl* NS = NNSLoc.getNestedNameSpecifier()->getAsNamespace()) {
+        if (NS->getName() == "a") {
+          Replace = Replacement(*SM, &NNSLoc, "", Context->getLangOpts());
+        }
+      }
+    }
+    return TestVisitor<NestedNameSpecifierAVisitor>::TraverseNestedNameSpecifierLoc(
+        NNSLoc);
+  }
+  Replacement Replace;
+};
+
+TEST(Replacement, ColonColon) {
+  NestedNameSpecifierAVisitor VisitNNSA;
+  EXPECT_TRUE(VisitNNSA.runOver("namespace a { void f() { ::a::f(); } }"));
+  expectReplacementAt(VisitNNSA.Replace, "input.cc", 25, 5);
+}
+
+TEST(Range, overlaps) {
+  EXPECT_TRUE(Range(10, 10).overlapsWith(Range(0, 11)));
+  EXPECT_TRUE(Range(0, 11).overlapsWith(Range(10, 10)));
+  EXPECT_FALSE(Range(10, 10).overlapsWith(Range(0, 10)));
+  EXPECT_FALSE(Range(0, 10).overlapsWith(Range(10, 10)));
+  EXPECT_TRUE(Range(0, 10).overlapsWith(Range(2, 6)));
+  EXPECT_TRUE(Range(2, 6).overlapsWith(Range(0, 10)));
+}
+
+TEST(Range, contains) {
+  EXPECT_TRUE(Range(0, 10).contains(Range(0, 10)));
+  EXPECT_TRUE(Range(0, 10).contains(Range(2, 6)));
+  EXPECT_FALSE(Range(2, 6).contains(Range(0, 10)));
+  EXPECT_FALSE(Range(0, 10).contains(Range(0, 11)));
+}
+
+TEST(DeduplicateTest, removesDuplicates) {
+  std::vector<Replacement> Input;
+  Input.push_back(Replacement("fileA", 50, 0, " foo "));
+  Input.push_back(Replacement("fileA", 10, 3, " bar "));
+  Input.push_back(Replacement("fileA", 10, 2, " bar ")); // Length differs
+  Input.push_back(Replacement("fileA", 9,  3, " bar ")); // Offset differs
+  Input.push_back(Replacement("fileA", 50, 0, " foo ")); // Duplicate
+  Input.push_back(Replacement("fileA", 51, 3, " bar "));
+  Input.push_back(Replacement("fileB", 51, 3, " bar ")); // Filename differs!
+  Input.push_back(Replacement("fileB", 60, 1, " bar "));
+  Input.push_back(Replacement("fileA", 60, 2, " bar "));
+  Input.push_back(Replacement("fileA", 51, 3, " moo ")); // Replacement text
+                                                         // differs!
+
+  std::vector<Replacement> Expected;
+  Expected.push_back(Replacement("fileA", 9,  3, " bar "));
+  Expected.push_back(Replacement("fileA", 10, 2, " bar "));
+  Expected.push_back(Replacement("fileA", 10, 3, " bar "));
+  Expected.push_back(Replacement("fileA", 50, 0, " foo "));
+  Expected.push_back(Replacement("fileA", 51, 3, " bar "));
+  Expected.push_back(Replacement("fileA", 51, 3, " moo "));
+  Expected.push_back(Replacement("fileB", 60, 1, " bar "));
+  Expected.push_back(Replacement("fileA", 60, 2, " bar "));
+
+  std::vector<Range> Conflicts; // Ignored for this test
+  deduplicate(Input, Conflicts);
+
+  EXPECT_EQ(3U, Conflicts.size());
+  EXPECT_EQ(Expected, Input);
+}
+
+TEST(DeduplicateTest, detectsConflicts) {
+  {
+    std::vector<Replacement> Input;
+    Input.push_back(Replacement("fileA", 0, 5, " foo "));
+    Input.push_back(Replacement("fileA", 0, 5, " foo ")); // Duplicate not a
+                                                          // conflict.
+    Input.push_back(Replacement("fileA", 2, 6, " bar "));
+    Input.push_back(Replacement("fileA", 7, 3, " moo "));
+
+    std::vector<Range> Conflicts;
+    deduplicate(Input, Conflicts);
+
+    // One duplicate is removed and the remaining three items form one
+    // conflicted range.
+    ASSERT_EQ(3u, Input.size());
+    ASSERT_EQ(1u, Conflicts.size());
+    ASSERT_EQ(0u, Conflicts.front().getOffset());
+    ASSERT_EQ(3u, Conflicts.front().getLength());
+  }
+  {
+    std::vector<Replacement> Input;
+
+    // Expected sorted order is shown. It is the sorted order to which the
+    // returned conflict info refers to.
+    Input.push_back(Replacement("fileA", 0,  5, " foo "));  // 0
+    Input.push_back(Replacement("fileA", 5,  5, " bar "));  // 1
+    Input.push_back(Replacement("fileA", 6,  0, " bar "));  // 3
+    Input.push_back(Replacement("fileA", 5,  5, " moo "));  // 2
+    Input.push_back(Replacement("fileA", 7,  2, " bar "));  // 4
+    Input.push_back(Replacement("fileA", 15, 5, " golf ")); // 5
+    Input.push_back(Replacement("fileA", 16, 5, " bag "));  // 6
+    Input.push_back(Replacement("fileA", 10, 3, " club ")); // 7
+
+    // #3 is special in that it is completely contained by another conflicting
+    // Replacement. #4 ensures #3 hasn't messed up the conflicting range size.
+
+    std::vector<Range> Conflicts;
+    deduplicate(Input, Conflicts);
+
+    // No duplicates
+    ASSERT_EQ(8u, Input.size());
+    ASSERT_EQ(2u, Conflicts.size());
+    ASSERT_EQ(1u, Conflicts[0].getOffset());
+    ASSERT_EQ(4u, Conflicts[0].getLength());
+    ASSERT_EQ(6u, Conflicts[1].getOffset());
+    ASSERT_EQ(2u, Conflicts[1].getLength());
+  }
+}
+
+class MergeReplacementsTest : public ::testing::Test {
+protected:
+  void mergeAndTestRewrite(StringRef Code, StringRef Intermediate,
+                           StringRef Result, const Replacements &First,
+                           const Replacements &Second) {
+    // These are mainly to verify the test itself and make it easier to read.
+    std::string AfterFirst = applyAllReplacements(Code, First);
+    std::string InSequenceRewrite = applyAllReplacements(AfterFirst, Second);
+    EXPECT_EQ(Intermediate, AfterFirst);
+    EXPECT_EQ(Result, InSequenceRewrite);
+
+    tooling::Replacements Merged = mergeReplacements(First, Second);
+    std::string MergedRewrite = applyAllReplacements(Code, Merged);
+    EXPECT_EQ(InSequenceRewrite, MergedRewrite);
+    if (InSequenceRewrite != MergedRewrite)
+      for (tooling::Replacement M : Merged)
+        llvm::errs() << M.getOffset() << " " << M.getLength() << " "
+                     << M.getReplacementText() << "\n";
+  }
+  void mergeAndTestRewrite(StringRef Code, const Replacements &First,
+                           const Replacements &Second) {
+    std::string InSequenceRewrite =
+        applyAllReplacements(applyAllReplacements(Code, First), Second);
+    tooling::Replacements Merged = mergeReplacements(First, Second);
+    std::string MergedRewrite = applyAllReplacements(Code, Merged);
+    EXPECT_EQ(InSequenceRewrite, MergedRewrite);
+    if (InSequenceRewrite != MergedRewrite)
+      for (tooling::Replacement M : Merged)
+        llvm::errs() << M.getOffset() << " " << M.getLength() << " "
+                     << M.getReplacementText() << "\n";
+  }
+};
+
+TEST_F(MergeReplacementsTest, Offsets) {
+  mergeAndTestRewrite("aaa", "aabab", "cacabab",
+                      {{"", 2, 0, "b"}, {"", 3, 0, "b"}},
+                      {{"", 0, 0, "c"}, {"", 1, 0, "c"}});
+  mergeAndTestRewrite("aaa", "babaa", "babacac",
+                      {{"", 0, 0, "b"}, {"", 1, 0, "b"}},
+                      {{"", 4, 0, "c"}, {"", 5, 0, "c"}});
+  mergeAndTestRewrite("aaaa", "aaa", "aac", {{"", 1, 1, ""}},
+                      {{"", 2, 1, "c"}});
+
+  mergeAndTestRewrite("aa", "bbabba", "bbabcba",
+                      {{"", 0, 0, "bb"}, {"", 1, 0, "bb"}}, {{"", 4, 0, "c"}});
+}
+
+TEST_F(MergeReplacementsTest, Concatenations) {
+  // Basic concatenations. It is important to merge these into a single
+  // replacement to ensure the correct order.
+  EXPECT_EQ((Replacements{{"", 0, 0, "ab"}}),
+            mergeReplacements({{"", 0, 0, "a"}}, {{"", 1, 0, "b"}}));
+  EXPECT_EQ((Replacements{{"", 0, 0, "ba"}}),
+            mergeReplacements({{"", 0, 0, "a"}}, {{"", 0, 0, "b"}}));
+  mergeAndTestRewrite("", "a", "ab", {{"", 0, 0, "a"}}, {{"", 1, 0, "b"}});
+  mergeAndTestRewrite("", "a", "ba", {{"", 0, 0, "a"}}, {{"", 0, 0, "b"}});
+}
+
+TEST_F(MergeReplacementsTest, NotChangingLengths) {
+  mergeAndTestRewrite("aaaa", "abba", "acca", {{"", 1, 2, "bb"}},
+                      {{"", 1, 2, "cc"}});
+  mergeAndTestRewrite("aaaa", "abba", "abcc", {{"", 1, 2, "bb"}},
+                      {{"", 2, 2, "cc"}});
+  mergeAndTestRewrite("aaaa", "abba", "ccba", {{"", 1, 2, "bb"}},
+                      {{"", 0, 2, "cc"}});
+  mergeAndTestRewrite("aaaaaa", "abbdda", "abccda",
+                      {{"", 1, 2, "bb"}, {"", 3, 2, "dd"}}, {{"", 2, 2, "cc"}});
+}
+
+TEST_F(MergeReplacementsTest, OverlappingRanges) {
+  mergeAndTestRewrite("aaa", "bbd", "bcbcd",
+                      {{"", 0, 1, "bb"}, {"", 1, 2, "d"}},
+                      {{"", 1, 0, "c"}, {"", 2, 0, "c"}});
+
+  mergeAndTestRewrite("aaaa", "aabbaa", "acccca", {{"", 2, 0, "bb"}},
+                      {{"", 1, 4, "cccc"}});
+  mergeAndTestRewrite("aaaa", "aababa", "acccca",
+                      {{"", 2, 0, "b"}, {"", 3, 0, "b"}}, {{"", 1, 4, "cccc"}});
+  mergeAndTestRewrite("aaaaaa", "abbbba", "abba", {{"", 1, 4, "bbbb"}},
+                      {{"", 2, 2, ""}});
+  mergeAndTestRewrite("aaaa", "aa", "cc", {{"", 1, 1, ""}, {"", 2, 1, ""}},
+                      {{"", 0, 2, "cc"}});
+  mergeAndTestRewrite("aa", "abbba", "abcbcba", {{"", 1, 0, "bbb"}},
+                      {{"", 2, 0, "c"}, {"", 3, 0, "c"}});
+
+  mergeAndTestRewrite("aaa", "abbab", "ccdd",
+                      {{"", 0, 1, ""}, {"", 2, 0, "bb"}, {"", 3, 0, "b"}},
+                      {{"", 0, 2, "cc"}, {"", 2, 3, "dd"}});
+  mergeAndTestRewrite("aa", "babbab", "ccdd",
+                      {{"", 0, 0, "b"}, {"", 1, 0, "bb"}, {"", 2, 0, "b"}},
+                      {{"", 0, 3, "cc"}, {"", 3, 3, "dd"}});
+}
+
+} // end namespace tooling
+} // end namespace clang