Add the Clang tblgen backends to Clang, and flip the switch to cause
the build systems to use clang-tblgen.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@141291 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/utils/TableGen/ClangASTNodesEmitter.cpp b/utils/TableGen/ClangASTNodesEmitter.cpp
new file mode 100644
index 0000000..d9d5a3c
--- /dev/null
+++ b/utils/TableGen/ClangASTNodesEmitter.cpp
@@ -0,0 +1,168 @@
+//=== ClangASTNodesEmitter.cpp - Generate Clang AST node tables -*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// These tablegen backends emit Clang AST node tables
+//
+//===----------------------------------------------------------------------===//
+
+#include "ClangASTNodesEmitter.h"
+#include <set>
+using namespace llvm;
+
+//===----------------------------------------------------------------------===//
+// Statement Node Tables (.inc file) generation.
+//===----------------------------------------------------------------------===//
+
+// Returns the first and last non-abstract subrecords
+// Called recursively to ensure that nodes remain contiguous
+std::pair<Record *, Record *> ClangASTNodesEmitter::EmitNode(
+                                                           const ChildMap &Tree,
+                                                           raw_ostream &OS,
+                                                           Record *Base) {
+  std::string BaseName = macroName(Base->getName());
+
+  ChildIterator i = Tree.lower_bound(Base), e = Tree.upper_bound(Base);
+
+  Record *First = 0, *Last = 0;
+  // This might be the pseudo-node for Stmt; don't assume it has an Abstract
+  // bit
+  if (Base->getValue("Abstract") && !Base->getValueAsBit("Abstract"))
+    First = Last = Base;
+
+  for (; i != e; ++i) {
+    Record *R = i->second;
+    bool Abstract = R->getValueAsBit("Abstract");
+    std::string NodeName = macroName(R->getName());
+
+    OS << "#ifndef " << NodeName << "\n";
+    OS << "#  define " << NodeName << "(Type, Base) "
+        << BaseName << "(Type, Base)\n";
+    OS << "#endif\n";
+
+    if (Abstract)
+      OS << "ABSTRACT_" << macroName(Root.getName()) << "(" << NodeName << "("
+          << R->getName() << ", " << baseName(*Base) << "))\n";
+    else
+      OS << NodeName << "(" << R->getName() << ", "
+          << baseName(*Base) << ")\n";
+
+    if (Tree.find(R) != Tree.end()) {
+      const std::pair<Record *, Record *> &Result
+        = EmitNode(Tree, OS, R);
+      if (!First && Result.first)
+        First = Result.first;
+      if (Result.second)
+        Last = Result.second;
+    } else {
+      if (!Abstract) {
+        Last = R;
+
+        if (!First)
+          First = R;
+      }
+    }
+
+    OS << "#undef " << NodeName << "\n\n";
+  }
+
+  if (First) {
+    assert (Last && "Got a first node but not a last node for a range!");
+    if (Base == &Root)
+      OS << "LAST_" << macroName(Root.getName()) << "_RANGE(";
+    else
+      OS << macroName(Root.getName()) << "_RANGE(";
+    OS << Base->getName() << ", " << First->getName() << ", "
+       << Last->getName() << ")\n\n";
+  }
+
+  return std::make_pair(First, Last);
+}
+
+void ClangASTNodesEmitter::run(raw_ostream &OS) {
+  // Write the preamble
+  OS << "#ifndef ABSTRACT_" << macroName(Root.getName()) << "\n";
+  OS << "#  define ABSTRACT_" << macroName(Root.getName()) << "(Type) Type\n";
+  OS << "#endif\n";
+
+  OS << "#ifndef " << macroName(Root.getName()) << "_RANGE\n";
+  OS << "#  define "
+     << macroName(Root.getName()) << "_RANGE(Base, First, Last)\n";
+  OS << "#endif\n\n";
+
+  OS << "#ifndef LAST_" << macroName(Root.getName()) << "_RANGE\n";
+  OS << "#  define LAST_" 
+     << macroName(Root.getName()) << "_RANGE(Base, First, Last) " 
+     << macroName(Root.getName()) << "_RANGE(Base, First, Last)\n";
+  OS << "#endif\n\n";
+ 
+  // Emit statements
+  const std::vector<Record*> Stmts
+    = Records.getAllDerivedDefinitions(Root.getName());
+
+  ChildMap Tree;
+
+  for (unsigned i = 0, e = Stmts.size(); i != e; ++i) {
+    Record *R = Stmts[i];
+
+    if (R->getValue("Base"))
+      Tree.insert(std::make_pair(R->getValueAsDef("Base"), R));
+    else
+      Tree.insert(std::make_pair(&Root, R));
+  }
+
+  EmitNode(Tree, OS, &Root);
+
+  OS << "#undef " << macroName(Root.getName()) << "\n";
+  OS << "#undef " << macroName(Root.getName()) << "_RANGE\n";
+  OS << "#undef LAST_" << macroName(Root.getName()) << "_RANGE\n";
+  OS << "#undef ABSTRACT_" << macroName(Root.getName()) << "\n";
+}
+
+void ClangDeclContextEmitter::run(raw_ostream &OS) {
+  // FIXME: Find a .td file format to allow for this to be represented better.
+
+  OS << "#ifndef DECL_CONTEXT\n";
+  OS << "#  define DECL_CONTEXT(DECL)\n";
+  OS << "#endif\n";
+  
+  OS << "#ifndef DECL_CONTEXT_BASE\n";
+  OS << "#  define DECL_CONTEXT_BASE(DECL) DECL_CONTEXT(DECL)\n";
+  OS << "#endif\n";
+  
+  typedef std::set<Record*> RecordSet;
+  typedef std::vector<Record*> RecordVector;
+  
+  RecordVector DeclContextsVector
+    = Records.getAllDerivedDefinitions("DeclContext");
+  RecordVector Decls = Records.getAllDerivedDefinitions("Decl");
+  RecordSet DeclContexts (DeclContextsVector.begin(), DeclContextsVector.end());
+   
+  for (RecordVector::iterator i = Decls.begin(), e = Decls.end(); i != e; ++i) {
+    Record *R = *i;
+
+    if (R->getValue("Base")) {
+      Record *B = R->getValueAsDef("Base");
+      if (DeclContexts.find(B) != DeclContexts.end()) {
+        OS << "DECL_CONTEXT_BASE(" << B->getName() << ")\n";
+        DeclContexts.erase(B);
+      }
+    }
+  }
+
+  // To keep identical order, RecordVector may be used
+  // instead of RecordSet.
+  for (RecordVector::iterator
+         i = DeclContextsVector.begin(), e = DeclContextsVector.end();
+       i != e; ++i)
+    if (DeclContexts.find(*i) != DeclContexts.end())
+      OS << "DECL_CONTEXT(" << (*i)->getName() << ")\n";
+
+  OS << "#undef DECL_CONTEXT\n";
+  OS << "#undef DECL_CONTEXT_BASE\n";
+}