Implement initial selectiondag printing support. This gets us a nice

graph with no labels! :)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@19441 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/SelectionDAG/SelectionDAGPrinter.cpp

@@ -0,0 +1,48 @@
+//===-- SelectionDAGPrinter.cpp - Implement SelectionDAG::viewGraph() -----===//
+// 
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+// 
+//===----------------------------------------------------------------------===//
+//
+// This implements the SelectionDAG::viewGraph method.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/CodeGen/SelectionDAG.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/Function.h"
+#include "llvm/Support/GraphWriter.h"
+#include <fstream>
+using namespace llvm;
+
+/// viewGraph - Pop up a ghostview window with the reachable parts of the DAG
+/// rendered using 'dot'.
+///
+void SelectionDAG::viewGraph() {
+  std::string Filename = "/tmp/dag." +
+    getMachineFunction().getFunction()->getName() + ".dot";
+  std::cerr << "Writing '" << Filename << "'... ";
+  std::ofstream F(Filename.c_str());
+
+  if (!F) {
+    std::cerr << "  error opening file for writing!\n";
+    return;
+  }
+
+  WriteGraph(F, this);
+  F.close();
+  std::cerr << "\n";
+
+  std::cerr << "Running 'dot' program... " << std::flush;
+  if (system(("dot -Tps -Nfontname=Courier -Gsize=7.5,10 " + Filename
+              + " > /tmp/dag.tempgraph.ps").c_str())) {
+    std::cerr << "Error running dot: 'dot' not in path?\n";
+  } else {
+    std::cerr << "\n";
+    system("gv /tmp/dag.tempgraph.ps");
+  }
+  system(("rm " + Filename + " /tmp/dag.tempgraph.ps").c_str());
+}