Add an emitter to handle the list of clang statement nodes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@103071 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/utils/TableGen/ClangASTNodesEmitter.cpp b/utils/TableGen/ClangASTNodesEmitter.cpp
new file mode 100644
index 0000000..f9366d9
--- /dev/null
+++ b/utils/TableGen/ClangASTNodesEmitter.cpp
@@ -0,0 +1,126 @@
+#include "ClangASTNodesEmitter.h"
+#include "Record.h"
+#include <vector>
+#include <stack>
+#include <string>
+#include <map>
+#include <utility>
+#include <clocale>
+using namespace llvm;
+
+//===----------------------------------------------------------------------===//
+// Statement Node Tables (.inc file) generation.
+//===----------------------------------------------------------------------===//
+
+// Sort to create a tree-like structure based on the 'Base' field.
+namespace {
+  // Create a macro-ized version of a name
+  std::string macroName(std::string S) {
+    for (unsigned i = 0; i < S.size(); ++i)
+      S[i] = std::toupper(S[i]);
+
+    return S;
+  }
+
+  // A map from a node to each of its derived nodes.
+  typedef std::multimap<Record*, Record*> ChildMap;
+  typedef ChildMap::const_iterator ChildIterator;
+
+  // Returns the first and last non-abstract subrecords
+  std::pair<Record *, Record *> EmitStmtNode(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(" << NodeName << "(" << R->getName() << ", "
+           << Base->getName() << "))\n";
+      else
+        OS << NodeName << "(" << R->getName() << ", "
+           << Base->getName() << ")\n";
+
+      if (Tree.find(R) != Tree.end()) {
+        const std::pair<Record *, Record *> &Result = EmitStmtNode(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";
+    }
+
+    assert(!First == !Last && "Got a first or last node, but not the other");
+
+    if (First) {
+      OS << "#ifndef FIRST_" << BaseName << "\n";
+      OS << "#  define FIRST_" << BaseName << "(CLASS)\n";
+      OS << "#endif\n";
+      OS << "#ifndef LAST_" << BaseName << "\n";
+      OS << "#  define LAST_" << BaseName << "(CLASS)\n";
+      OS << "#endif\n\n";
+
+      OS << "FIRST_" << BaseName << "(" << First->getName() << ")\n";
+      OS << "LAST_" << BaseName << "(" << Last->getName() << ")\n\n";
+    }
+
+    OS << "#undef FIRST_" << BaseName << "\n";
+    OS << "#undef LAST_" << BaseName << "\n\n";
+
+    return std::make_pair(First, Last);
+  }
+}
+
+void ClangStmtNodesEmitter::run(raw_ostream &OS) {
+  // Write the preamble
+  OS << "#ifndef ABSTRACT\n";
+  OS << "#  define ABSTRACT(Stmt) Stmt\n";
+  OS << "#endif\n\n";
+
+  // Emit statements
+  const std::vector<Record*> Stmts = Records.getAllDerivedDefinitions("Stmt");
+
+  ChildMap Tree;
+
+  // Create a pseudo-record to serve as the Stmt node, which isn't actually
+  // output.
+  Record Stmt ("Stmt", SMLoc());
+
+  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(&Stmt, R));
+  }
+
+  EmitStmtNode(Tree, OS, &Stmt);
+
+  OS << "#undef STMT\n";
+  OS << "#undef ABSTRACT\n";
+}
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