[clang-format] Drop clangFrontend dependency for FormatTests

[arichardson]

Summary

This allows building the clang-format unit tests in only 657 ninja steps
rather than 1257 which allows for much faster incremental builds after a
git pull.

Depends on D89708

[MyDeveloperDay]

LGTM, I'm for anything that speeds up the build

clang/unittests/Format/CMakeLists.txt

add_clang_unittest(FormatTests
   SortIncludesTest.cpp
   UsingDeclarationsSorterTest.cpp
   )
 
 clang_target_link_libraries(FormatTests
   PRIVATE
   clangBasic
   clangFormat
-  clangFrontend
   clangRewrite
   clangToolingCore
   )

clang/unittests/Format/CleanupTest.cpp

 //===- unittest/Format/CleanupTest.cpp - Code cleanup unit tests ----------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #include "clang/Format/Format.h"
 
 #include "../Tooling/ReplacementTest.h"
-#include "../Tooling/RewriterTestContext.h"
 #include "clang/Tooling/Core/Replacement.h"
 
 #include "gtest/gtest.h"
 
 using clang::tooling::ReplacementTest;
 using clang::tooling::toReplacements;
 
 namespace clang {

clang/unittests/Format/FormatTest.cpp

 //===- unittest/Format/FormatTest.cpp - Formatting unit tests -------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #include "clang/Format/Format.h"
 
 #include "../Tooling/ReplacementTest.h"
 #include "FormatTestUtils.h"
 
-#include "clang/Frontend/TextDiagnosticPrinter.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "gtest/gtest.h"
 
 #define DEBUG_TYPE "format-test"
 
 using clang::tooling::ReplacementTest;
 using clang::tooling::toReplacements;

clang/unittests/Format/FormatTestComments.cpp

 //===- unittest/Format/FormatTestComments.cpp - Formatting unit tests -----===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #include "clang/Format/Format.h"
 
 #include "../Tooling/ReplacementTest.h"
 #include "FormatTestUtils.h"
 
-#include "clang/Frontend/TextDiagnosticPrinter.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "gtest/gtest.h"
 
 #define DEBUG_TYPE "format-test"
 
 using clang::tooling::ReplacementTest;
 

clang/unittests/Format/FormatTestObjC.cpp

 //===- unittest/Format/FormatTestObjC.cpp - Formatting unit tests----------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #include "clang/Format/Format.h"
 
 #include "../Tooling/ReplacementTest.h"
 #include "FormatTestUtils.h"
 
-#include "clang/Frontend/TextDiagnosticPrinter.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "gtest/gtest.h"
 
 #define DEBUG_TYPE "format-test"
 
 using clang::tooling::ReplacementTest;
 

clang/unittests/Format/FormatTestRawStrings.cpp

 //===- unittest/Format/FormatTestRawStrings.cpp - Formatting unit tests ---===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #include "clang/Format/Format.h"
 
 #include "../Tooling/ReplacementTest.h"
 #include "FormatTestUtils.h"
 
-#include "clang/Frontend/TextDiagnosticPrinter.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "gtest/gtest.h"
 
 #define DEBUG_TYPE "format-test"
 
 using clang::tooling::ReplacementTest;
 using clang::tooling::toReplacements;

clang/unittests/Format/NamespaceEndCommentsFixerTest.cpp

 //===- NamespaceEndCommentsFixerTest.cpp - Formatting unit tests ----------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #include "clang/Format/Format.h"
 
-#include "clang/Frontend/TextDiagnosticPrinter.h"
 #include "llvm/Support/Debug.h"
 #include "gtest/gtest.h"
 
 #define DEBUG_TYPE "namespace-end-comments-fixer-test"
 
 namespace clang {
 namespace format {
 namespace {

clang/unittests/Tooling/RewriterTestContext.h

 #ifndef LLVM_CLANG_UNITTESTS_TOOLING_REWRITERTESTCONTEXT_H
 #define LLVM_CLANG_UNITTESTS_TOOLING_REWRITERTESTCONTEXT_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/TextDiagnosticPrinter.h"
 #include "clang/Rewrite/Core/Rewriter.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Path.h"
 #include "llvm/Support/raw_ostream.h"
 
 namespace clang {
 
+/// \brief A very simple diagnostic consumer that prints to stderr and keeps
+/// track of the number of diagnostics.
+///
+/// This avoids a dependency on clangFrontend for FormatTests.
+struct RewriterDiagnosticConsumer : public DiagnosticConsumer {
+  RewriterDiagnosticConsumer() : NumDiagnosticsSeen(0) {}
+  void HandleDiagnostic(DiagnosticsEngine::Level DiagLevel,
+                        const Diagnostic &Info) override {
+    ++NumDiagnosticsSeen;
+    SmallString<100> OutStr;
+    Info.FormatDiagnostic(OutStr);
+    llvm::errs() << OutStr;
+  }
+  unsigned NumDiagnosticsSeen;
+};
+
 /// \brief A class that sets up a ready to use Rewriter.
 ///
 /// Useful in unit tests that need a Rewriter. Creates all dependencies
 /// of a Rewriter with default values for testing and provides convenience
 /// methods, which help with writing tests that change files.
 class RewriterTestContext {
  public:
    RewriterTestContext()
        : DiagOpts(new DiagnosticOptions()),
          Diagnostics(IntrusiveRefCntPtr<DiagnosticIDs>(new DiagnosticIDs),
                      &*DiagOpts),
-         DiagnosticPrinter(llvm::outs(), &*DiagOpts),
          InMemoryFileSystem(new llvm::vfs::InMemoryFileSystem),
          OverlayFileSystem(
              new llvm::vfs::OverlayFileSystem(llvm::vfs::getRealFileSystem())),
          Files(FileSystemOptions(), OverlayFileSystem),
          Sources(Diagnostics, Files), Rewrite(Sources, Options) {
      Diagnostics.setClient(&DiagnosticPrinter, false);
      // FIXME: To make these tests truly in-memory, we need to overlay the
      // builtin headers.
std::string getFileContentFromDisk(StringRef Name) {
     // FIXME: Figure out whether there is a way to get the SourceManger to
     // reopen the file.
     auto FileBuffer = Files.getBufferForFile(Path);
     return std::string((*FileBuffer)->getBuffer());
   }
 
   IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts;
   DiagnosticsEngine Diagnostics;
-  TextDiagnosticPrinter DiagnosticPrinter;
+  RewriterDiagnosticConsumer DiagnosticPrinter;
   IntrusiveRefCntPtr<llvm::vfs::InMemoryFileSystem> InMemoryFileSystem;
   IntrusiveRefCntPtr<llvm::vfs::OverlayFileSystem> OverlayFileSystem;
   FileManager Files;
   SourceManager Sources;
   LangOptions Options;
   Rewriter Rewrite;
 
   // Will be set once on disk files are generated.
   llvm::StringMap<std::string> TemporaryFiles;
 };
 
 } // end namespace clang
 
 #endif