diff --git a/clang-tools-extra/clang-apply-replacements/lib/Tooling/ApplyReplacements.cpp b/clang-tools-extra/clang-apply-replacements/lib/Tooling/ApplyReplacements.cpp
--- a/clang-tools-extra/clang-apply-replacements/lib/Tooling/ApplyReplacements.cpp
+++ b/clang-tools-extra/clang-apply-replacements/lib/Tooling/ApplyReplacements.cpp
@@ -169,9 +169,11 @@
 
   for (const auto &TU : TUDs)
     for (const auto &D : TU.Diagnostics)
-      for (const auto &Fix : D.Fix)
-        for (const tooling::Replacement &R : Fix.second)
-          AddToGroup(R, true);
+      if (const auto *ChoosenFix = D.getChosenFix()) {
+        for (const auto &Fix : *ChoosenFix)
+          for (const tooling::Replacement &R : Fix.second)
+            AddToGroup(R, true);
+      }
 
   // Sort replacements per file to keep consistent behavior when
   // clang-apply-replacements run on differents machine.
diff --git a/clang-tools-extra/clang-tidy/ClangTidy.cpp b/clang-tools-extra/clang-tidy/ClangTidy.cpp
--- a/clang-tools-extra/clang-tidy/ClangTidy.cpp
+++ b/clang-tools-extra/clang-tidy/ClangTidy.cpp
@@ -35,6 +35,7 @@
 #include "clang/Lex/Preprocessor.h"
 #include "clang/Rewrite/Frontend/FixItRewriter.h"
 #include "clang/Rewrite/Frontend/FrontendActions.h"
+#include "clang/Tooling/Core/Diagnostic.h"
 #if CLANG_ENABLE_STATIC_ANALYZER
 #include "clang/StaticAnalyzer/Core/BugReporter/PathDiagnostic.h"
 #include "clang/StaticAnalyzer/Frontend/AnalysisConsumer.h"
@@ -125,15 +126,17 @@
       }
       auto Diag = Diags.Report(Loc, Diags.getCustomDiagID(Level, "%0 [%1]"))
                   << Message.Message << Name;
-      for (const auto &FileAndReplacements : Error.Fix) {
-        for (const auto &Repl : FileAndReplacements.second) {
-          SourceLocation FixLoc;
-          ++TotalFixes;
-          bool CanBeApplied = false;
-          if (Repl.isApplicable()) {
-            SmallString<128> FixAbsoluteFilePath = Repl.getFilePath();
-            Files.makeAbsolutePath(FixAbsoluteFilePath);
-            if (ApplyFixes) {
+
+      const llvm::StringMap<Replacements> *ChosenFix = Error.getChosenFix();
+      if (ApplyFixes && ChosenFix) {
+        for (const auto &FileAndReplacements : *ChosenFix) {
+          for (const auto &Repl : FileAndReplacements.second) {
+            ++TotalFixes;
+            bool CanBeApplied = false;
+            if (Repl.isApplicable()) {
+              SourceLocation FixLoc;
+              SmallString<128> FixAbsoluteFilePath = Repl.getFilePath();
+              Files.makeAbsolutePath(FixAbsoluteFilePath);
               tooling::Replacement R(FixAbsoluteFilePath, Repl.getOffset(),
                                      Repl.getLength(),
                                      Repl.getReplacementText());
@@ -158,28 +161,17 @@
                   llvm::errs()
                       << "Can't resolve conflict, skipping the replacement.\n";
                 }
-
               } else {
                 CanBeApplied = true;
                 ++AppliedFixes;
               }
+              FixLoc = getLocation(FixAbsoluteFilePath, Repl.getOffset());
+              FixLocations.push_back(std::make_pair(FixLoc, CanBeApplied));
             }
-            FixLoc = getLocation(FixAbsoluteFilePath, Repl.getOffset());
-            SourceLocation FixEndLoc =
-                FixLoc.getLocWithOffset(Repl.getLength());
-            // Retrieve the source range for applicable fixes. Macro definitions
-            // on the command line have locations in a virtual buffer and don't
-            // have valid file paths and are therefore not applicable.
-            CharSourceRange Range =
-                CharSourceRange::getCharRange(SourceRange(FixLoc, FixEndLoc));
-            Diag << FixItHint::CreateReplacement(Range,
-                                                 Repl.getReplacementText());
           }
-
-          if (ApplyFixes)
-            FixLocations.push_back(std::make_pair(FixLoc, CanBeApplied));
         }
       }
+      reportFix(Diag, Error.Message.Fix);
     }
     for (auto Fix : FixLocations) {
       Diags.Report(Fix.first, Fix.second ? diag::note_fixit_applied
@@ -250,10 +242,33 @@
     return SourceMgr.getLocForStartOfFile(ID).getLocWithOffset(Offset);
   }
 
+  void reportFix(const DiagnosticBuilder &Diag,
+                 const llvm::StringMap<Replacements> &Fix) {
+    for (const auto &FileAndReplacements : Fix) {
+      for (const auto &Repl : FileAndReplacements.second) {
+        if (!Repl.isApplicable())
+          continue;
+        SmallString<128> FixAbsoluteFilePath = Repl.getFilePath();
+        Files.makeAbsolutePath(FixAbsoluteFilePath);
+        SourceLocation FixLoc =
+            getLocation(FixAbsoluteFilePath, Repl.getOffset());
+        SourceLocation FixEndLoc = FixLoc.getLocWithOffset(Repl.getLength());
+        // Retrieve the source range for applicable fixes. Macro definitions
+        // on the command line have locations in a virtual buffer and don't
+        // have valid file paths and are therefore not applicable.
+        CharSourceRange Range =
+            CharSourceRange::getCharRange(SourceRange(FixLoc, FixEndLoc));
+        Diag << FixItHint::CreateReplacement(Range, Repl.getReplacementText());
+      }
+    }
+  }
+
   void reportNote(const tooling::DiagnosticMessage &Message) {
     SourceLocation Loc = getLocation(Message.FilePath, Message.FileOffset);
-    Diags.Report(Loc, Diags.getCustomDiagID(DiagnosticsEngine::Note, "%0"))
+    auto Diag =
+        Diags.Report(Loc, Diags.getCustomDiagID(DiagnosticsEngine::Note, "%0"))
         << Message.Message;
+    reportFix(Diag, Message.Fix);
   }
 
   FileManager Files;
diff --git a/clang-tools-extra/clang-tidy/ClangTidyDiagnosticConsumer.cpp b/clang-tools-extra/clang-tidy/ClangTidyDiagnosticConsumer.cpp
--- a/clang-tools-extra/clang-tidy/ClangTidyDiagnosticConsumer.cpp
+++ b/clang-tools-extra/clang-tidy/ClangTidyDiagnosticConsumer.cpp
@@ -18,8 +18,10 @@
 #include "ClangTidyDiagnosticConsumer.h"
 #include "ClangTidyOptions.h"
 #include "clang/AST/ASTDiagnostic.h"
+#include "clang/Basic/Diagnostic.h"
 #include "clang/Basic/DiagnosticOptions.h"
 #include "clang/Frontend/DiagnosticRenderer.h"
+#include "clang/Tooling/Core/Diagnostic.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SmallString.h"
 #include <tuple>
@@ -68,6 +70,9 @@
                        SmallVectorImpl<CharSourceRange> &Ranges,
                        ArrayRef<FixItHint> Hints) override {
     assert(Loc.isValid());
+    tooling::DiagnosticMessage *DiagWithFix =
+        Level == DiagnosticsEngine::Note ? &Error.Notes.back() : &Error.Message;
+
     for (const auto &FixIt : Hints) {
       CharSourceRange Range = FixIt.RemoveRange;
       assert(Range.getBegin().isValid() && Range.getEnd().isValid() &&
@@ -77,7 +82,8 @@
 
       tooling::Replacement Replacement(Loc.getManager(), Range,
                                        FixIt.CodeToInsert);
-      llvm::Error Err = Error.Fix[Replacement.getFilePath()].add(Replacement);
+      llvm::Error Err =
+          DiagWithFix->Fix[Replacement.getFilePath()].add(Replacement);
       // FIXME: better error handling (at least, don't let other replacements be
       // applied).
       if (Err) {
@@ -581,9 +587,17 @@
 
   // Compute error sizes.
   std::vector<int> Sizes;
-  for (const auto &Error : Errors) {
+  std::vector<
+      std::pair<ClangTidyError *, llvm::StringMap<tooling::Replacements> *>>
+      ErrorFixes;
+  for (auto &Error : Errors) {
+    if (const auto *Fix = Error.getChosenFix())
+      ErrorFixes.emplace_back(
+          &Error, const_cast<llvm::StringMap<tooling::Replacements> *>(Fix));
+  }
+  for (const auto &ErrorAndFix : ErrorFixes) {
     int Size = 0;
-    for (const auto &FileAndReplaces : Error.Fix) {
+    for (const auto &FileAndReplaces : *ErrorAndFix.second) {
       for (const auto &Replace : FileAndReplaces.second)
         Size += Replace.getLength();
     }
@@ -592,8 +606,8 @@
 
   // Build events from error intervals.
   std::map<std::string, std::vector<Event>> FileEvents;
-  for (unsigned I = 0; I < Errors.size(); ++I) {
-    for (const auto &FileAndReplace : Errors[I].Fix) {
+  for (unsigned I = 0; I < ErrorFixes.size(); ++I) {
+    for (const auto &FileAndReplace : *ErrorFixes[I].second) {
       for (const auto &Replace : FileAndReplace.second) {
         unsigned Begin = Replace.getOffset();
         unsigned End = Begin + Replace.getLength();
@@ -608,7 +622,7 @@
     }
   }
 
-  std::vector<bool> Apply(Errors.size(), true);
+  std::vector<bool> Apply(ErrorFixes.size(), true);
   for (auto &FileAndEvents : FileEvents) {
     std::vector<Event> &Events = FileAndEvents.second;
     // Sweep.
@@ -627,10 +641,10 @@
     assert(OpenIntervals == 0 && "Amount of begin/end points doesn't match");
   }
 
-  for (unsigned I = 0; I < Errors.size(); ++I) {
+  for (unsigned I = 0; I < ErrorFixes.size(); ++I) {
     if (!Apply[I]) {
-      Errors[I].Fix.clear();
-      Errors[I].Notes.emplace_back(
+      ErrorFixes[I].second->clear();
+      ErrorFixes[I].first->Notes.emplace_back(
           "this fix will not be applied because it overlaps with another fix");
     }
   }
diff --git a/clang-tools-extra/clang-tidy/add_new_check.py b/clang-tools-extra/clang-tidy/add_new_check.py
--- a/clang-tools-extra/clang-tidy/add_new_check.py
+++ b/clang-tools-extra/clang-tidy/add_new_check.py
@@ -137,7 +137,8 @@
   if (MatchedDecl->getName().startswith("awesome_"))
     return;
   diag(MatchedDecl->getLocation(), "function %%0 is insufficiently awesome")
-      << MatchedDecl
+      << MatchedDecl;
+  diag(MatchedDecl->getLocation(), "insert 'awesome'", DiagnosticIDs::Note)
       << FixItHint::CreateInsertion(MatchedDecl->getLocation(), "awesome_");
 }
 
diff --git a/clang-tools-extra/clang-tidy/misc/UnusedUsingDeclsCheck.cpp b/clang-tools-extra/clang-tidy/misc/UnusedUsingDeclsCheck.cpp
--- a/clang-tools-extra/clang-tidy/misc/UnusedUsingDeclsCheck.cpp
+++ b/clang-tools-extra/clang-tidy/misc/UnusedUsingDeclsCheck.cpp
@@ -154,7 +154,10 @@
   for (const auto &Context : Contexts) {
     if (!Context.IsUsed) {
       diag(Context.FoundUsingDecl->getLocation(), "using decl %0 is unused")
-          << Context.FoundUsingDecl
+          << Context.FoundUsingDecl;
+      // Emit a fix and a fix description of the check;
+      diag(Context.FoundUsingDecl->getLocation(),
+           /*FixDescription=*/"remove the using", DiagnosticIDs::Note)
           << FixItHint::CreateRemoval(Context.UsingDeclRange);
     }
   }
diff --git a/clang-tools-extra/test/clang-apply-replacements/Inputs/basic/file1.yaml b/clang-tools-extra/test/clang-apply-replacements/Inputs/basic/file1.yaml
--- a/clang-tools-extra/test/clang-apply-replacements/Inputs/basic/file1.yaml
+++ b/clang-tools-extra/test/clang-apply-replacements/Inputs/basic/file1.yaml
@@ -2,24 +2,25 @@
 MainSourceFile:     source1.cpp
 Diagnostics:
   - DiagnosticName: test-basic
-    Message: Fix
-    FilePath: $(path)/basic.h
-    FileOffset: 242
-    Replacements:
-      - FilePath:        $(path)/basic.h
-        Offset:          242
-        Length:          26
-        ReplacementText: 'auto & elem : ints'
-      - FilePath:        $(path)/basic.h
-        Offset:          276
-        Length:          22
-        ReplacementText: ''
-      - FilePath:        $(path)/basic.h
-        Offset:          298
-        Length:          1
-        ReplacementText: elem
-      - FilePath:        $(path)/../basic/basic.h
-        Offset:          148
-        Length:          0
-        ReplacementText: 'override '
+    DiagnosticMessage:
+      Message: Fix
+      FilePath: $(path)/basic.h
+      FileOffset: 242
+      Replacements:
+        - FilePath:        $(path)/basic.h
+          Offset:          242
+          Length:          26
+          ReplacementText: 'auto & elem : ints'
+        - FilePath:        $(path)/basic.h
+          Offset:          276
+          Length:          22
+          ReplacementText: ''
+        - FilePath:        $(path)/basic.h
+          Offset:          298
+          Length:          1
+          ReplacementText: elem
+        - FilePath:        $(path)/../basic/basic.h
+          Offset:          148
+          Length:          0
+          ReplacementText: 'override '
 ...
diff --git a/clang-tools-extra/test/clang-apply-replacements/Inputs/basic/file2.yaml b/clang-tools-extra/test/clang-apply-replacements/Inputs/basic/file2.yaml
--- a/clang-tools-extra/test/clang-apply-replacements/Inputs/basic/file2.yaml
+++ b/clang-tools-extra/test/clang-apply-replacements/Inputs/basic/file2.yaml
@@ -2,12 +2,13 @@
 MainSourceFile:     source2.cpp
 Diagnostics:
   - DiagnosticName: test-basic
-    Message: Fix
-    FilePath: $(path)/basic.h
-    FileOffset: 148
-    Replacements:
-      - FilePath:        $(path)/../basic/basic.h
-        Offset:          298
-        Length:          1
-        ReplacementText: elem
+    DiagnosticMessage:
+      Message: Fix
+      FilePath: $(path)/basic.h
+      FileOffset: 148
+      Replacements:
+        - FilePath:        $(path)/../basic/basic.h
+          Offset:          298
+          Length:          1
+          ReplacementText: elem
 ...
diff --git a/clang-tools-extra/test/clang-apply-replacements/Inputs/conflict/file1.yaml b/clang-tools-extra/test/clang-apply-replacements/Inputs/conflict/file1.yaml
--- a/clang-tools-extra/test/clang-apply-replacements/Inputs/conflict/file1.yaml
+++ b/clang-tools-extra/test/clang-apply-replacements/Inputs/conflict/file1.yaml
@@ -2,20 +2,21 @@
 MainSourceFile: source1.cpp
 Diagnostics:
   - DiagnosticName: test-conflict
-    Message: Fix
-    FilePath: $(path)/common.h
-    FileOffset: 106
-    Replacements:
-      - FilePath:        $(path)/common.h
-        Offset:          106
-        Length:          26
-        ReplacementText: 'auto & i : ints'
-      - FilePath:        $(path)/common.h
-        Offset:          140
-        Length:          7
-        ReplacementText: i
-      - FilePath:        $(path)/common.h
-        Offset:          160
-        Length:          12
-        ReplacementText: ''
+    DiagnosticMessage:
+      Message: Fix
+      FilePath: $(path)/common.h
+      FileOffset: 106
+      Replacements:
+        - FilePath:        $(path)/common.h
+          Offset:          106
+          Length:          26
+          ReplacementText: 'auto & i : ints'
+        - FilePath:        $(path)/common.h
+          Offset:          140
+          Length:          7
+          ReplacementText: i
+        - FilePath:        $(path)/common.h
+          Offset:          160
+          Length:          12
+          ReplacementText: ''
 ...
diff --git a/clang-tools-extra/test/clang-apply-replacements/Inputs/conflict/file2.yaml b/clang-tools-extra/test/clang-apply-replacements/Inputs/conflict/file2.yaml
--- a/clang-tools-extra/test/clang-apply-replacements/Inputs/conflict/file2.yaml
+++ b/clang-tools-extra/test/clang-apply-replacements/Inputs/conflict/file2.yaml
@@ -2,20 +2,21 @@
 MainSourceFile: source2.cpp
 Diagnostics:
   - DiagnosticName:  test-conflict
-    Message: Fix
-    FilePath: $(path)/common.h
-    FileOffset: 106
-    Replacements:
-      - FilePath:        $(path)/common.h
-        Offset:          106
-        Length:          26
-        ReplacementText: 'int & elem : ints'
-      - FilePath:        $(path)/common.h
-        Offset:          140
-        Length:          7
-        ReplacementText: elem
-      - FilePath:        $(path)/common.h
-        Offset:          169
-        Length:          1
-        ReplacementText: nullptr
+    DiagnosticMessage:
+      Message: Fix
+      FilePath: $(path)/common.h
+      FileOffset: 106
+      Replacements:
+        - FilePath:        $(path)/common.h
+          Offset:          106
+          Length:          26
+          ReplacementText: 'int & elem : ints'
+        - FilePath:        $(path)/common.h
+          Offset:          140
+          Length:          7
+          ReplacementText: elem
+        - FilePath:        $(path)/common.h
+          Offset:          169
+          Length:          1
+          ReplacementText: nullptr
 ...
diff --git a/clang-tools-extra/test/clang-apply-replacements/Inputs/conflict/file3.yaml b/clang-tools-extra/test/clang-apply-replacements/Inputs/conflict/file3.yaml
--- a/clang-tools-extra/test/clang-apply-replacements/Inputs/conflict/file3.yaml
+++ b/clang-tools-extra/test/clang-apply-replacements/Inputs/conflict/file3.yaml
@@ -2,12 +2,13 @@
 MainSourceFile: source1.cpp
 Diagnostics:
   - DiagnosticName:  test-conflict
-    Message: Fix
-    FilePath: $(path)/common.h
-    FileOffset: 169
-    Replacements:
-      - FilePath:        $(path)/common.h
-        Offset:          169
-        Length:          0
-        ReplacementText: "(int*)"
+    DiagnosticMessage:
+      Message: Fix
+      FilePath: $(path)/common.h
+      FileOffset: 169
+      Replacements:
+        - FilePath:        $(path)/common.h
+          Offset:          169
+          Length:          0
+          ReplacementText: "(int*)"
 ...
diff --git a/clang-tools-extra/test/clang-apply-replacements/Inputs/crlf/file1.yaml b/clang-tools-extra/test/clang-apply-replacements/Inputs/crlf/file1.yaml
--- a/clang-tools-extra/test/clang-apply-replacements/Inputs/crlf/file1.yaml
+++ b/clang-tools-extra/test/clang-apply-replacements/Inputs/crlf/file1.yaml
@@ -2,12 +2,13 @@
 MainSourceFile:      source1.cpp
 Diagnostics:
   - DiagnosticName:  test-crlf
-    Message: Fix
-    FilePath: $(path)/crlf.cpp
-    FileOffset: 79
-    Replacements:
-      - FilePath:        $(path)/crlf.cpp
-        Offset:          79
-        Length:          1
-        ReplacementText: nullptr
+    DiagnosticMessage:
+      Message: Fix
+      FilePath: $(path)/crlf.cpp
+      FileOffset: 79
+      Replacements:
+        - FilePath:        $(path)/crlf.cpp
+          Offset:          79
+          Length:          1
+          ReplacementText: nullptr
 ...
diff --git a/clang-tools-extra/test/clang-apply-replacements/Inputs/format/no.yaml b/clang-tools-extra/test/clang-apply-replacements/Inputs/format/no.yaml
--- a/clang-tools-extra/test/clang-apply-replacements/Inputs/format/no.yaml
+++ b/clang-tools-extra/test/clang-apply-replacements/Inputs/format/no.yaml
@@ -2,12 +2,13 @@
 MainSourceFile:  no.cpp
 Diagnostics:
   - DiagnosticName:  test-no
-    Message: Fix
-    FilePath: $(path)/no.cpp
-    FileOffset: 94
-    Replacements:
-      - FilePath:        $(path)/no.cpp
-        Offset:          94
-        Length:          3
-        ReplacementText: 'auto '
+    DiagnosticMessage:
+      Message: Fix
+      FilePath: $(path)/no.cpp
+      FileOffset: 94
+      Replacements:
+        - FilePath:        $(path)/no.cpp
+          Offset:          94
+          Length:          3
+          ReplacementText: 'auto '
 ...
diff --git a/clang-tools-extra/test/clang-apply-replacements/Inputs/format/yes.yaml b/clang-tools-extra/test/clang-apply-replacements/Inputs/format/yes.yaml
--- a/clang-tools-extra/test/clang-apply-replacements/Inputs/format/yes.yaml
+++ b/clang-tools-extra/test/clang-apply-replacements/Inputs/format/yes.yaml
@@ -4,24 +4,25 @@
 MainSourceFile:  yes.cpp
 Diagnostics:
   - DiagnosticName:  test-yes
-    Message: Fix
-    FilePath: $(path)/yes.cpp
-    FileOffset: 494
-    Replacements:
-      - FilePath:        $(path)/yes.cpp
-        Offset:          494
-        Length:          1
-        ReplacementText: nullptr
-      - FilePath:        $(path)/yes.cpp
-        Offset:          410
-        Length:          1
-        ReplacementText: nullptr
-      - FilePath:        $(path)/yes.cpp
-        Offset:          454
-        Length:          1
-        ReplacementText: nullptr
-      - FilePath:        $(path)/yes.cpp
-        Offset:          108
-        Length:          38
-        ReplacementText: 'auto '
+    DiagnosticMessage:
+      Message: Fix
+      FilePath: $(path)/yes.cpp
+      FileOffset: 494
+      Replacements:
+        - FilePath:        $(path)/yes.cpp
+          Offset:          494
+          Length:          1
+          ReplacementText: nullptr
+        - FilePath:        $(path)/yes.cpp
+          Offset:          410
+          Length:          1
+          ReplacementText: nullptr
+        - FilePath:        $(path)/yes.cpp
+          Offset:          454
+          Length:          1
+          ReplacementText: nullptr
+        - FilePath:        $(path)/yes.cpp
+          Offset:          108
+          Length:          38
+          ReplacementText: 'auto '
 ...
diff --git a/clang-tools-extra/test/clang-apply-replacements/Inputs/identical/file1.yaml b/clang-tools-extra/test/clang-apply-replacements/Inputs/identical/file1.yaml
--- a/clang-tools-extra/test/clang-apply-replacements/Inputs/identical/file1.yaml
+++ b/clang-tools-extra/test/clang-apply-replacements/Inputs/identical/file1.yaml
@@ -2,13 +2,14 @@
 MainSourceFile:     identical.cpp
 Diagnostics:
   - DiagnosticName: test-identical-insertion
-    Message: Fix
-    FilePath: $(path)/identical.cpp
-    FileOffset: 12
-    Replacements:
-      - FilePath:        $(path)/identical.cpp
-        Offset:          12
-        Length:          0
-        ReplacementText: '0'
+    DiagnosticMessage:
+      Message: Fix
+      FilePath: $(path)/identical.cpp
+      FileOffset: 12
+      Replacements:
+        - FilePath:        $(path)/identical.cpp
+          Offset:          12
+          Length:          0
+          ReplacementText: '0'
 ...
 
diff --git a/clang-tools-extra/test/clang-apply-replacements/Inputs/identical/file2.yaml b/clang-tools-extra/test/clang-apply-replacements/Inputs/identical/file2.yaml
--- a/clang-tools-extra/test/clang-apply-replacements/Inputs/identical/file2.yaml
+++ b/clang-tools-extra/test/clang-apply-replacements/Inputs/identical/file2.yaml
@@ -2,13 +2,14 @@
 MainSourceFile:     identical.cpp
 Diagnostics:
   - DiagnosticName: test-identical-insertion
-    Message: Fix
-    FilePath: $(path)/identical.cpp
-    FileOffset: 12
-    Replacements:
-      - FilePath:        $(path)/identical.cpp
-        Offset:          12
-        Length:          0
-        ReplacementText: '0'
+    DiagnosticMessage:
+      Message: Fix
+      FilePath: $(path)/identical.cpp
+      FileOffset: 12
+      Replacements:
+        - FilePath:        $(path)/identical.cpp
+          Offset:          12
+          Length:          0
+          ReplacementText: '0'
 ...
 
diff --git a/clang-tools-extra/test/clang-apply-replacements/Inputs/order-dependent/file1.yaml b/clang-tools-extra/test/clang-apply-replacements/Inputs/order-dependent/file1.yaml
--- a/clang-tools-extra/test/clang-apply-replacements/Inputs/order-dependent/file1.yaml
+++ b/clang-tools-extra/test/clang-apply-replacements/Inputs/order-dependent/file1.yaml
@@ -2,12 +2,13 @@
 MainSourceFile:     order-dependent.cpp
 Diagnostics:
   - DiagnosticName: test-order-dependent-insertion
-    Message: Fix
-    FilePath: $(path)/order-dependent.cpp
-    FileOffset: 12
-    Replacements:
-      - FilePath:        $(path)/order-dependent.cpp
-        Offset:          12
-        Length:          0
-        ReplacementText: '0'
+    DiagnosticMessage:
+      Message: Fix
+      FilePath: $(path)/order-dependent.cpp
+      FileOffset: 12
+      Replacements:
+        - FilePath:        $(path)/order-dependent.cpp
+          Offset:          12
+          Length:          0
+          ReplacementText: '0'
 ...
diff --git a/clang-tools-extra/test/clang-apply-replacements/Inputs/order-dependent/file2.yaml b/clang-tools-extra/test/clang-apply-replacements/Inputs/order-dependent/file2.yaml
--- a/clang-tools-extra/test/clang-apply-replacements/Inputs/order-dependent/file2.yaml
+++ b/clang-tools-extra/test/clang-apply-replacements/Inputs/order-dependent/file2.yaml
@@ -2,12 +2,13 @@
 MainSourceFile:     order-dependent.cpp
 Diagnostics:
   - DiagnosticName: test-order-dependent-insertion
-    Message: Fix
-    FilePath: $(path)/order-dependent.cpp
-    FileOffset: 12
-    Replacements:
-      - FilePath:        $(path)/order-dependent.cpp
-        Offset:          12
-        Length:          0
-        ReplacementText: '1'
+    DiagnosticMessage:
+      Message: Fix
+      FilePath: $(path)/order-dependent.cpp
+      FileOffset: 12
+      Replacements:
+        - FilePath:        $(path)/order-dependent.cpp
+          Offset:          12
+          Length:          0
+          ReplacementText: '1'
 ...
diff --git a/clang-tools-extra/test/clang-tidy/export-diagnostics.cpp b/clang-tools-extra/test/clang-tidy/export-diagnostics.cpp
--- a/clang-tools-extra/test/clang-tidy/export-diagnostics.cpp
+++ b/clang-tools-extra/test/clang-tidy/export-diagnostics.cpp
@@ -13,16 +13,19 @@
 // CHECK-YAML-NEXT: MainSourceFile:  '{{.*}}-input.cpp'
 // CHECK-YAML-NEXT: Diagnostics:
 // CHECK-YAML-NEXT:   - DiagnosticName:  clang-diagnostic-missing-prototypes
-// CHECK-YAML-NEXT:     Message:         'no previous prototype for function ''ff'''
-// CHECK-YAML-NEXT:     FileOffset:      30
-// CHECK-YAML-NEXT:     FilePath:        '{{.*}}-input.cpp'
+// CHECK-YAML-NEXT:     DiagnosticMessage:
+// CHECK-YAML-NEXT:       Message:         'no previous prototype for function
+// ''ff'''
+// CHECK-YAML-NEXT:       FilePath:        '{{.*}}-input.cpp'
+// CHECK-YAML-NEXT:       FileOffset:      30
+// CHECK-YAML-NEXT:       Replacements:      []
 // CHECK-YAML-NEXT:     Notes:
 // CHECK-YAML-NEXT:       - Message:         'expanded from macro ''X'''
 // CHECK-YAML-NEXT:         FilePath:        '{{.*}}-input.cpp'
 // CHECK-YAML-NEXT:         FileOffset:      18
+// CHECK-YAML-NEXT:         Replacements:    []
 // CHECK-YAML-NEXT:       - Message:         expanded from here
 // CHECK-YAML-NEXT:         FilePath:        ''
 // CHECK-YAML-NEXT:         FileOffset:      0
-// CHECK-YAML-NEXT:     Replacements:    []
+// CHECK-YAML-NEXT:         Replacements:    []
 // CHECK-YAML-NEXT: ...
-
diff --git a/clang-tools-extra/unittests/clang-apply-replacements/ApplyReplacementsTest.cpp b/clang-tools-extra/unittests/clang-apply-replacements/ApplyReplacementsTest.cpp
--- a/clang-tools-extra/unittests/clang-apply-replacements/ApplyReplacementsTest.cpp
+++ b/clang-tools-extra/unittests/clang-apply-replacements/ApplyReplacementsTest.cpp
@@ -26,7 +26,6 @@
   TUs.push_back({MainSourceFile,
                  {{DiagnosticName,
                    Message,
-                   Replacements,
                    {},
                    Diagnostic::Warning,
                    BuildDirectory}}});
diff --git a/clang-tools-extra/unittests/clang-tidy/ClangTidyTest.h b/clang-tools-extra/unittests/clang-tidy/ClangTidyTest.h
--- a/clang-tools-extra/unittests/clang-tidy/ClangTidyTest.h
+++ b/clang-tools-extra/unittests/clang-tidy/ClangTidyTest.h
@@ -14,6 +14,7 @@
 #include "clang/ASTMatchers/ASTMatchFinder.h"
 #include "clang/Frontend/CompilerInstance.h"
 #include "clang/Frontend/FrontendActions.h"
+#include "clang/Tooling/Core/Replacement.h"
 #include "clang/Tooling/Refactoring.h"
 #include "clang/Tooling/Tooling.h"
 #include "llvm/ADT/Optional.h"
@@ -131,16 +132,17 @@
   tooling::Replacements Fixes;
   std::vector<ClangTidyError> Diags = DiagConsumer.take();
   for (const ClangTidyError &Error : Diags) {
-    for (const auto &FileAndFixes : Error.Fix) {
-      for (const auto &Fix : FileAndFixes.second) {
-        auto Err = Fixes.add(Fix);
-        // FIXME: better error handling. Keep the behavior for now.
-        if (Err) {
-          llvm::errs() << llvm::toString(std::move(Err)) << "\n";
-          return "";
+    if (const auto *ChosenFix = Error.getChosenFix())
+      for (const auto &FileAndFixes : *ChosenFix) {
+        for (const auto &Fix : FileAndFixes.second) {
+          auto Err = Fixes.add(Fix);
+          // FIXME: better error handling. Keep the behavior for now.
+          if (Err) {
+            llvm::errs() << llvm::toString(std::move(Err)) << "\n";
+            return "";
+          }
         }
       }
-    }
   }
   if (Errors)
     *Errors = std::move(Diags);
diff --git a/clang/include/clang/Tooling/Core/Diagnostic.h b/clang/include/clang/Tooling/Core/Diagnostic.h
--- a/clang/include/clang/Tooling/Core/Diagnostic.h
+++ b/clang/include/clang/Tooling/Core/Diagnostic.h
@@ -42,6 +42,9 @@
   std::string Message;
   std::string FilePath;
   unsigned FileOffset;
+
+  /// Fixes for this diagnostic, grouped by file path.
+  llvm::StringMap<Replacements> Fix;
 };
 
 /// Represents the diagnostic with the level of severity and possible
@@ -58,19 +61,20 @@
              StringRef BuildDirectory);
 
   Diagnostic(llvm::StringRef DiagnosticName, const DiagnosticMessage &Message,
-             const llvm::StringMap<Replacements> &Fix,
              const SmallVector<DiagnosticMessage, 1> &Notes, Level DiagLevel,
              llvm::StringRef BuildDirectory);
 
+  // Get the chosen fix to apply for this diagnostic.
+  // FIXME: currently we choose the first non-empty fix, extend it to support
+  // fix selection.
+  const llvm::StringMap<Replacements> *getChosenFix() const;
+
   /// Name identifying the Diagnostic.
   std::string DiagnosticName;
 
   /// Message associated to the diagnostic.
   DiagnosticMessage Message;
 
-  /// Fixes to apply, grouped by file path.
-  llvm::StringMap<Replacements> Fix;
-
   /// Potential notes about the diagnostic.
   SmallVector<DiagnosticMessage, 1> Notes;
 
diff --git a/clang/include/clang/Tooling/DiagnosticsYaml.h b/clang/include/clang/Tooling/DiagnosticsYaml.h
--- a/clang/include/clang/Tooling/DiagnosticsYaml.h
+++ b/clang/include/clang/Tooling/DiagnosticsYaml.h
@@ -31,6 +31,20 @@
     Io.mapRequired("Message", M.Message);
     Io.mapOptional("FilePath", M.FilePath);
     Io.mapOptional("FileOffset", M.FileOffset);
+    std::vector<clang::tooling::Replacement> Fixes;
+    for (auto &Replacements : M.Fix) {
+      for (auto &Replacement : Replacements.second)
+        Fixes.push_back(Replacement);
+    }
+    Io.mapRequired("Replacements", Fixes);
+    for (auto &Fix : Fixes) {
+      llvm::Error Err = M.Fix[Fix.getFilePath()].add(Fix);
+      if (Err) {
+        // FIXME: Implement better conflict handling.
+        llvm::errs() << "Fix conflicts with existing fix: "
+                     << llvm::toString(std::move(Err)) << "\n";
+      }
+    }
   }
 };
 
@@ -43,12 +57,11 @@
         : DiagLevel(clang::tooling::Diagnostic::Level::Warning) {}
 
     NormalizedDiagnostic(const IO &, const clang::tooling::Diagnostic &D)
-        : DiagnosticName(D.DiagnosticName), Message(D.Message), Fix(D.Fix),
-          Notes(D.Notes), DiagLevel(D.DiagLevel),
-          BuildDirectory(D.BuildDirectory) {}
+        : DiagnosticName(D.DiagnosticName), Message(D.Message), Notes(D.Notes),
+          DiagLevel(D.DiagLevel), BuildDirectory(D.BuildDirectory) {}
 
     clang::tooling::Diagnostic denormalize(const IO &) {
-      return clang::tooling::Diagnostic(DiagnosticName, Message, Fix, Notes,
+      return clang::tooling::Diagnostic(DiagnosticName, Message, Notes,
                                         DiagLevel, BuildDirectory);
     }
 
@@ -64,28 +77,10 @@
     MappingNormalization<NormalizedDiagnostic, clang::tooling::Diagnostic> Keys(
         Io, D);
     Io.mapRequired("DiagnosticName", Keys->DiagnosticName);
-    Io.mapRequired("Message", Keys->Message.Message);
-    Io.mapRequired("FileOffset", Keys->Message.FileOffset);
-    Io.mapRequired("FilePath", Keys->Message.FilePath);
+    Io.mapRequired("DiagnosticMessage", Keys->Message);
     Io.mapOptional("Notes", Keys->Notes);
 
     // FIXME: Export properly all the different fields.
-
-    std::vector<clang::tooling::Replacement> Fixes;
-    for (auto &Replacements : Keys->Fix) {
-      for (auto &Replacement : Replacements.second) {
-        Fixes.push_back(Replacement);
-      }
-    }
-    Io.mapRequired("Replacements", Fixes);
-    for (auto &Fix : Fixes) {
-      llvm::Error Err = Keys->Fix[Fix.getFilePath()].add(Fix);
-      if (Err) {
-        // FIXME: Implement better conflict handling.
-        llvm::errs() << "Fix conflicts with existing fix: "
-                     << llvm::toString(std::move(Err)) << "\n";
-      }
-    }
   }
 };
 
diff --git a/clang/lib/Tooling/Core/Diagnostic.cpp b/clang/lib/Tooling/Core/Diagnostic.cpp
--- a/clang/lib/Tooling/Core/Diagnostic.cpp
+++ b/clang/lib/Tooling/Core/Diagnostic.cpp
@@ -12,6 +12,7 @@
 
 #include "clang/Tooling/Core/Diagnostic.h"
 #include "clang/Basic/SourceManager.h"
+#include "llvm/ADT/STLExtras.h"
 
 namespace clang {
 namespace tooling {
@@ -40,11 +41,21 @@
 
 Diagnostic::Diagnostic(llvm::StringRef DiagnosticName,
                        const DiagnosticMessage &Message,
-                       const llvm::StringMap<Replacements> &Fix,
                        const SmallVector<DiagnosticMessage, 1> &Notes,
                        Level DiagLevel, llvm::StringRef BuildDirectory)
-    : DiagnosticName(DiagnosticName), Message(Message), Fix(Fix), Notes(Notes),
+    : DiagnosticName(DiagnosticName), Message(Message), Notes(Notes),
       DiagLevel(DiagLevel), BuildDirectory(BuildDirectory) {}
 
+const llvm::StringMap<Replacements> *Diagnostic::getChosenFix() const {
+  if (!Message.Fix.empty())
+    return &Message.Fix;
+  auto Iter = llvm::find_if(Notes, [](const tooling::DiagnosticMessage &D) {
+    return !D.Fix.empty();
+  });
+  if (Iter != Notes.end())
+    return &Iter->Fix;
+  return nullptr;
+}
+
 } // end namespace tooling
 } // end namespace clang
diff --git a/clang/unittests/Tooling/DiagnosticsYamlTest.cpp b/clang/unittests/Tooling/DiagnosticsYamlTest.cpp
--- a/clang/unittests/Tooling/DiagnosticsYamlTest.cpp
+++ b/clang/unittests/Tooling/DiagnosticsYamlTest.cpp
@@ -20,11 +20,13 @@
 using clang::tooling::Diagnostic;
 
 static DiagnosticMessage makeMessage(const std::string &Message, int FileOffset,
-                                     const std::string &FilePath) {
+                                     const std::string &FilePath,
+                                     const StringMap<Replacements> &Fix) {
   DiagnosticMessage DiagMessage;
   DiagMessage.Message = Message;
   DiagMessage.FileOffset = FileOffset;
   DiagMessage.FilePath = FilePath;
+  DiagMessage.Fix = Fix;
   return DiagMessage;
 }
 
@@ -32,10 +34,52 @@
                                  const std::string &Message, int FileOffset,
                                  const std::string &FilePath,
                                  const StringMap<Replacements> &Fix) {
-  return Diagnostic(DiagnosticName, makeMessage(Message, FileOffset, FilePath),
-                    Fix, {}, Diagnostic::Warning, "path/to/build/directory");
+  return Diagnostic(DiagnosticName,
+                    makeMessage(Message, FileOffset, FilePath, Fix), {},
+                    Diagnostic::Warning, "path/to/build/directory");
 }
 
+static const char *YAMLContent =
+    "---\n"
+    "MainSourceFile:  'path/to/source.cpp'\n"
+    "Diagnostics:     \n"
+    "  - DiagnosticName:  'diagnostic#1\'\n"
+    "    DiagnosticMessage: \n"
+    "      Message:         'message #1'\n"
+    "      FilePath:        'path/to/source.cpp'\n"
+    "      FileOffset:      55\n"
+    "      Replacements:    \n"
+    "        - FilePath:        'path/to/source.cpp'\n"
+    "          Offset:          100\n"
+    "          Length:          12\n"
+    "          ReplacementText: 'replacement #1'\n"
+    "  - DiagnosticName:  'diagnostic#2'\n"
+    "    DiagnosticMessage: \n"
+    "      Message:         'message #2'\n"
+    "      FilePath:        'path/to/header.h'\n"
+    "      FileOffset:      60\n"
+    "      Replacements:    \n"
+    "        - FilePath:        'path/to/header.h'\n"
+    "          Offset:          62\n"
+    "          Length:          2\n"
+    "          ReplacementText: 'replacement #2'\n"
+    "  - DiagnosticName:  'diagnostic#3'\n"
+    "    DiagnosticMessage: \n"
+    "      Message:         'message #3'\n"
+    "      FilePath:        'path/to/source2.cpp'\n"
+    "      FileOffset:      72\n"
+    "      Replacements:    []\n"
+    "    Notes:           \n"
+    "      - Message:         Note1\n"
+    "        FilePath:        'path/to/note1.cpp'\n"
+    "        FileOffset:      88\n"
+    "        Replacements:    []\n"
+    "      - Message:         Note2\n"
+    "        FilePath:        'path/to/note2.cpp'\n"
+    "        FileOffset:      99\n"
+    "        Replacements:    []\n"
+    "...\n";
+
 TEST(DiagnosticsYamlTest, serializesDiagnostics) {
   TranslationUnitDiagnostics TUD;
   TUD.MainSourceFile = "path/to/source.cpp";
@@ -55,9 +99,9 @@
   TUD.Diagnostics.push_back(makeDiagnostic("diagnostic#3", "message #3", 72,
                                            "path/to/source2.cpp", {}));
   TUD.Diagnostics.back().Notes.push_back(
-      makeMessage("Note1", 88, "path/to/note1.cpp"));
+      makeMessage("Note1", 88, "path/to/note1.cpp", {}));
   TUD.Diagnostics.back().Notes.push_back(
-      makeMessage("Note2", 99, "path/to/note2.cpp"));
+      makeMessage("Note2", 99, "path/to/note2.cpp", {}));
 
   std::string YamlContent;
   raw_string_ostream YamlContentStream(YamlContent);
@@ -65,80 +109,12 @@
   yaml::Output YAML(YamlContentStream);
   YAML << TUD;
 
-  EXPECT_EQ("---\n"
-            "MainSourceFile:  'path/to/source.cpp'\n"
-            "Diagnostics:     \n"
-            "  - DiagnosticName:  'diagnostic#1\'\n"
-            "    Message:         'message #1'\n"
-            "    FileOffset:      55\n"
-            "    FilePath:        'path/to/source.cpp'\n"
-            "    Replacements:    \n"
-            "      - FilePath:        'path/to/source.cpp'\n"
-            "        Offset:          100\n"
-            "        Length:          12\n"
-            "        ReplacementText: 'replacement #1'\n"
-            "  - DiagnosticName:  'diagnostic#2'\n"
-            "    Message:         'message #2'\n"
-            "    FileOffset:      60\n"
-            "    FilePath:        'path/to/header.h'\n"
-            "    Replacements:    \n"
-            "      - FilePath:        'path/to/header.h'\n"
-            "        Offset:          62\n"
-            "        Length:          2\n"
-            "        ReplacementText: 'replacement #2'\n"
-            "  - DiagnosticName:  'diagnostic#3'\n"
-            "    Message:         'message #3'\n"
-            "    FileOffset:      72\n"
-            "    FilePath:        'path/to/source2.cpp'\n"
-            "    Notes:           \n"
-            "      - Message:         Note1\n"
-            "        FilePath:        'path/to/note1.cpp'\n"
-            "        FileOffset:      88\n"
-            "      - Message:         Note2\n"
-            "        FilePath:        'path/to/note2.cpp'\n"
-            "        FileOffset:      99\n"
-            "    Replacements:    []\n"
-            "...\n",
-            YamlContentStream.str());
+  EXPECT_EQ(YAMLContent, YamlContentStream.str());
 }
 
 TEST(DiagnosticsYamlTest, deserializesDiagnostics) {
-  std::string YamlContent = "---\n"
-                            "MainSourceFile:  path/to/source.cpp\n"
-                            "Diagnostics:     \n"
-                            "  - DiagnosticName:  'diagnostic#1'\n"
-                            "    Message:         'message #1'\n"
-                            "    FileOffset:      55\n"
-                            "    FilePath:        path/to/source.cpp\n"
-                            "    Replacements:    \n"
-                            "      - FilePath:        path/to/source.cpp\n"
-                            "        Offset:          100\n"
-                            "        Length:          12\n"
-                            "        ReplacementText: 'replacement #1'\n"
-                            "  - DiagnosticName:  'diagnostic#2'\n"
-                            "    Message:         'message #2'\n"
-                            "    FileOffset:      60\n"
-                            "    FilePath:        path/to/header.h\n"
-                            "    Replacements:    \n"
-                            "      - FilePath:        path/to/header.h\n"
-                            "        Offset:          62\n"
-                            "        Length:          2\n"
-                            "        ReplacementText: 'replacement #2'\n"
-                            "  - DiagnosticName:  'diagnostic#3'\n"
-                            "    Message:         'message #3'\n"
-                            "    FileOffset:      98\n"
-                            "    FilePath:        path/to/source.cpp\n"
-                            "    Notes:\n"
-                            "      - Message:         Note1\n"
-                            "        FilePath:        'path/to/note1.cpp'\n"
-                            "        FileOffset:      66\n"
-                            "      - Message:         Note2\n"
-                            "        FilePath:        'path/to/note2.cpp'\n"
-                            "        FileOffset:      77\n"
-                            "    Replacements:    []\n"
-                            "...\n";
   TranslationUnitDiagnostics TUDActual;
-  yaml::Input YAML(YamlContent);
+  yaml::Input YAML(YAMLContent);
   YAML >> TUDActual;
 
   ASSERT_FALSE(YAML.error());
@@ -160,7 +136,7 @@
   EXPECT_EQ("message #1", D1.Message.Message);
   EXPECT_EQ(55u, D1.Message.FileOffset);
   EXPECT_EQ("path/to/source.cpp", D1.Message.FilePath);
-  std::vector<Replacement> Fixes1 = getFixes(D1.Fix);
+  std::vector<Replacement> Fixes1 = getFixes(D1.Message.Fix);
   ASSERT_EQ(1u, Fixes1.size());
   EXPECT_EQ("path/to/source.cpp", Fixes1[0].getFilePath());
   EXPECT_EQ(100u, Fixes1[0].getOffset());
@@ -172,7 +148,7 @@
   EXPECT_EQ("message #2", D2.Message.Message);
   EXPECT_EQ(60u, D2.Message.FileOffset);
   EXPECT_EQ("path/to/header.h", D2.Message.FilePath);
-  std::vector<Replacement> Fixes2 = getFixes(D2.Fix);
+  std::vector<Replacement> Fixes2 = getFixes(D2.Message.Fix);
   ASSERT_EQ(1u, Fixes2.size());
   EXPECT_EQ("path/to/header.h", Fixes2[0].getFilePath());
   EXPECT_EQ(62u, Fixes2[0].getOffset());
@@ -182,15 +158,15 @@
   Diagnostic D3 = TUDActual.Diagnostics[2];
   EXPECT_EQ("diagnostic#3", D3.DiagnosticName);
   EXPECT_EQ("message #3", D3.Message.Message);
-  EXPECT_EQ(98u, D3.Message.FileOffset);
-  EXPECT_EQ("path/to/source.cpp", D3.Message.FilePath);
+  EXPECT_EQ(72u, D3.Message.FileOffset);
+  EXPECT_EQ("path/to/source2.cpp", D3.Message.FilePath);
   EXPECT_EQ(2u, D3.Notes.size());
   EXPECT_EQ("Note1", D3.Notes[0].Message);
-  EXPECT_EQ(66u, D3.Notes[0].FileOffset);
+  EXPECT_EQ(88u, D3.Notes[0].FileOffset);
   EXPECT_EQ("path/to/note1.cpp", D3.Notes[0].FilePath);
   EXPECT_EQ("Note2", D3.Notes[1].Message);
-  EXPECT_EQ(77u, D3.Notes[1].FileOffset);
+  EXPECT_EQ(99u, D3.Notes[1].FileOffset);
   EXPECT_EQ("path/to/note2.cpp", D3.Notes[1].FilePath);
-  std::vector<Replacement> Fixes3 = getFixes(D3.Fix);
+  std::vector<Replacement> Fixes3 = getFixes(D3.Message.Fix);
   EXPECT_TRUE(Fixes3.empty());
 }