Cleanup include dependencies for LLVMTableGen

[serge-sans-paille]

Summary

Based on the output of include-what-you-use. No other library seems affected by
the new forward declaration.

$ clang++ -E -Iinclude -I../llvm/include ../llvm/lib/TableGen/*.cpp -std=c++14 -fno-rtti -fno-exceptions | wc -l
before: 795231
after: 750654

Related Discourse thread: https://llvm.discourse.group/t/include-what-you-use-include-cleanup

[RKSimon]

contexts with diff could be useful

[serge-sans-paille]

In D118374#3276476, @RKSimon wrote:

contexts with diff could be useful

I purposely removed them to avoid uploading too large of a diff file :-/ I'll do that

[serge-sans-paille]

Reupload with context

[RKSimon]

(style) Please can you run clang-format on the includes to sort them correctly?

llvm/lib/TableGen/DetailedRecordsBackend.cpp

26

Looks like clang-format is complaining about the include sort order?

llvm/lib/TableGen/JSONBackend.cpp

20

Again, sort the includes

[serge-sans-paille]

clang-format includes

[RKSimon]

LGTM

llvm/lib/TableGen/DetailedRecordsBackend.cpp

 //===- DetailedRecordBackend.cpp - Detailed Records Report      -*- C++ -*-===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 //
 // This Tablegen backend prints a report that includes all the global 
 // variables, classes, and records in complete detail. It includes more
 // detail than the default TableGen printer backend.
 //
 //===----------------------------------------------------------------------===//
 
 #include "llvm/ADT/ArrayRef.h"
-#include "llvm/ADT/DenseMap.h"
-#include "llvm/ADT/StringExtras.h"
-#include "llvm/Support/Format.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/FormatVariadic.h"
-#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/SMLoc.h"
 #include "llvm/Support/SourceMgr.h"
+#include "llvm/Support/raw_ostream.h"
 #include "llvm/TableGen/Error.h"
 #include "llvm/TableGen/Record.h"
-#include "llvm/TableGen/TableGenBackend.h"
+#include <map>
+#include <memory>
 #include <string>
 #include <utility>
 
 #define DEBUG_TYPE "detailed-records-backend"
 
 #define NL "\n"
 
 using namespace llvm;
 

llvm/lib/TableGen/JSONBackend.cpp

 //===- JSONBackend.cpp - Generate a JSON dump of all records. -*- C++ -*-=====//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 //
 // This TableGen back end generates a machine-readable representation
 // of all the classes and records defined by the input, in JSON format.
 //
 //===----------------------------------------------------------------------===//
 
-#include "llvm/ADT/BitVector.h"
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/Support/Casting.h"
 #include "llvm/Support/Debug.h"
-#include "llvm/TableGen/Error.h"
-#include "llvm/TableGen/Record.h"
-#include "llvm/TableGen/TableGenBackend.h"
+#include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/JSON.h"
+#include "llvm/TableGen/Record.h"
 
 #define DEBUG_TYPE "json-emitter"
 
 using namespace llvm;
 
 namespace {
 
 class JSONEmitter {
 private:

llvm/lib/TableGen/Main.cpp

 // description in some predefined format.  In practice, this is used by the LLVM
 // code generators to automate generation of a code generator through a
 // high-level description of the target.
 //
 //===----------------------------------------------------------------------===//
 
 #include "llvm/TableGen/Main.h"
 #include "TGParser.h"
-#include "llvm/ADT/StringExtras.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/ToolOutputFile.h"
 #include "llvm/TableGen/Error.h"
 #include "llvm/TableGen/Record.h"
 #include <algorithm>
-#include <cstdio>
 #include <system_error>
 using namespace llvm;
 
 static cl::opt<std::string>
 OutputFilename("o", cl::desc("Output filename"), cl::value_desc("filename"),
                cl::init("-"));
 
 static cl::opt<std::string>

llvm/lib/TableGen/Record.cpp

 //===- Record.cpp - Record implementation ---------------------------------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 //
 // Implement the tablegen record classes.
 //
 //===----------------------------------------------------------------------===//
 
+#include "llvm/TableGen/Record.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/FoldingSet.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/SmallVector.h"
-#include "llvm/ADT/Statistic.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/ADT/StringMap.h"
 #include "llvm/ADT/StringRef.h"
-#include "llvm/ADT/StringSet.h"
 #include "llvm/Config/llvm-config.h"
 #include "llvm/Support/Allocator.h"
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/ManagedStatic.h"
 #include "llvm/Support/SMLoc.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/TableGen/Error.h"
-#include "llvm/TableGen/Record.h"
 #include <cassert>
 #include <cstdint>
-#include <memory>
 #include <map>
+#include <memory>
 #include <string>
 #include <utility>
 #include <vector>
 
 using namespace llvm;
 
 #define DEBUG_TYPE "tblgen-records"
 
if (Value) {
       }
     }
     return Value == nullptr;
   }
   Value = nullptr;
   return false;
 }
 
-#include "llvm/TableGen/Record.h"
 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
+#include "llvm/TableGen/Record.h"
 LLVM_DUMP_METHOD void RecordVal::dump() const { errs() << *this; }
 #endif
 
 void RecordVal::print(raw_ostream &OS, bool PrintSem) const {
   if (isNonconcreteOK()) OS << "field ";
   OS << getPrintType() << " " << getNameInitAsString();
 
   if (getValue())

llvm/lib/TableGen/SetTheory.cpp

 //===- SetTheory.cpp - Generate ordered sets from DAG expressions ---------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 //
 // This file implements the SetTheory class that computes ordered sets of
 // Records from DAG expressions.
 //
 //===----------------------------------------------------------------------===//
 
+#include "llvm/TableGen/SetTheory.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/SmallVector.h"
-#include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/Format.h"
 #include "llvm/Support/SMLoc.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/TableGen/Error.h"
 #include "llvm/TableGen/Record.h"
-#include "llvm/TableGen/SetTheory.h"
 #include <algorithm>
 #include <cstdint>
 #include <string>
 #include <utility>
 
 using namespace llvm;
 
 // Define the standard operators.

llvm/lib/TableGen/TGParser.cpp

 //===- TGParser.cpp - Parser for TableGen Files ---------------------------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 //
 // Implement the Parser for TableGen.
 //
 //===----------------------------------------------------------------------===//
 
 #include "TGParser.h"
+#include "llvm/ADT/DenseMapInfo.h"
 #include "llvm/ADT/None.h"
-#include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/ADT/Twine.h"
 #include "llvm/Config/llvm-config.h"
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/raw_ostream.h"
-#include "llvm/Support/SourceMgr.h"
 #include <algorithm>
 #include <cassert>
 #include <cstdint>
 #include <limits>
 
 using namespace llvm;
 
 //===----------------------------------------------------------------------===//

llvm/lib/TableGen/TableGenBackendSkeleton.cpp

 //===- SkeletonEmitter.cpp - Skeleton TableGen backend          -*- C++ -*-===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 //
 // This Tablegen backend emits ...
 //
 //===----------------------------------------------------------------------===//
 
-#include "llvm/ADT/ArrayRef.h"
-#include "llvm/ADT/DenseMap.h"
-#include "llvm/ADT/StringExtras.h"
-#include "llvm/Support/Format.h"
-#include "llvm/Support/MemoryBuffer.h"
-#include "llvm/Support/SourceMgr.h"
-#include "llvm/TableGen/Error.h"
-#include "llvm/TableGen/Record.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Support/ErrorHandling.h"
 #include "llvm/TableGen/TableGenBackend.h"
-#include <algorithm>
-#include <set>
-#include <string>
-#include <vector>
 
 #define DEBUG_TYPE "skeleton-emitter"
 
+namespace llvm {
+class RecordKeeper;
+class raw_ostream;
+} // namespace llvm
+
 using namespace llvm;
 
 namespace {
 
 // Any helper data structures can be defined here. Some backends use
 // structs to collect information from the records.
 
 class SkeletonEmitter {