- Allow printing generic LLVM graphs to 'dot' files, so they can be

    visualized easily.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@4061 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 188 insertions, 0 deletions

diff --git a/include/llvm/Support/DOTGraphTraits.h b/include/llvm/Support/DOTGraphTraits.h
new file mode 100644
index 0000000..28cf365
--- /dev/null
+++ b/include/llvm/Support/DOTGraphTraits.h
@@ -0,0 +1,65 @@
+//===-- Support/DotGraphTraits.h - Customize .dot output -------*- C++ -*--===//
+//
+// This file defines a template class that can be used to customize dot output
+// graphs generated by the GraphWriter.h file.  The default implementation of
+// this file will produce a simple, but not very polished graph.  By
+// specializing this template, lots of customization opportunities are possible.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SUPPORT_DOTGRAPHTRAITS_H
+#define SUPPORT_DOTGRAPHTRAITS_H
+
+#include <string>
+
+/// DefaultDOTGraphTraits - This class provides the default implementations of
+/// all of the DOTGraphTraits methods.  If a specialization does not need to
+/// override all methods here it should inherit so that it can get the default
+/// implementations.
+///
+struct DefaultDOTGraphTraits {
+  /// getGraphName - Return the label for the graph as a whole.  Printed at the
+  /// top of the graph.
+  ///
+  static std::string getGraphName(void *Graph) { return ""; }
+
+  /// getNodeLabel - Given a node and a pointer to the top level graph, return
+  /// the label to print in the node.
+  static std::string getNodeLabel(void *Node, void *Graph) { return ""; }
+
+  /// If you want to specify custom node attributes, this is the place to do so
+  ///
+  static std::string getNodeAttributes(void *Node) { return ""; }
+
+  /// If you want to override the dot attributes printed for a particular edge,
+  /// override this method.
+  template<typename EdgeIter>
+  static std::string getEdgeAttributes(void *Node, EdgeIter EI) { return ""; }
+
+  /// getEdgeSourceLabel - If you want to label the edge source itself,
+  /// implement this method.
+  template<typename EdgeIter>
+  static std::string getEdgeSourceLabel(void *Node, EdgeIter I) { return ""; }
+
+  /// edgeTargetsEdgeSource - This method returns true if this outgoing edge
+  /// should actually target another edge source, not a node.  If this method is
+  /// implemented, getEdgeTarget should be implemented.
+  template<typename EdgeIter>
+  static bool edgeTargetsEdgeSource(void *Node, EdgeIter I) { return false; }
+
+  /// getEdgeTarget - If edgeTargetsEdgeSource returns true, this method is
+  /// called to determine which outgoing edge of Node is the target of this
+  /// edge.
+  template<typename EdgeIter>
+  static EdgeIter getEdgeTarget(void *Node, EdgeIter I) { return I; }
+};
+
+
+/// DOTGraphTraits - Template class that can be specialized to customize how
+/// graphs are converted to 'dot' graphs.  When specializing, you may inherit
+/// from DefaultDOTGraphTraits if you don't need to override everything.
+///
+template <typename Ty>
+class DOTGraphTraits : public DefaultDOTGraphTraits {};
+
+#endif
diff --git a/include/llvm/Support/GraphWriter.h b/include/llvm/Support/GraphWriter.h
new file mode 100644
index 0000000..01851d5
--- /dev/null
+++ b/include/llvm/Support/GraphWriter.h
@@ -0,0 +1,123 @@
+//===-- Support/GraphWriter.h - Write a graph to a .dot file ---*- C++ -*--===//
+//
+// This file defines a simple interface that can be used to print out generic
+// LLVM graphs to ".dot" files.  "dot" is a tool that is part of the AT&T
+// graphviz package (http://www.research.att.com/sw/tools/graphviz/) which can
+// be used to turn the files output by this interface into a variety of
+// different graphics formats.
+//
+// Graphs do not need to implement any interface past what is already required
+// by the GraphTraits template, but they can choose to implement specializations
+// of the DOTGraphTraits template if they want to customize the graphs output in
+// any way.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SUPPORT_GRAPHWRITER_H
+#define SUPPORT_GRAPHWRITER_H
+
+#include "Support/DOTGraphTraits.h"
+#include "Support/DepthFirstIterator.h"
+#include <ostream>
+
+namespace DOT {  // Private functions...
+  inline std::string EscapeString(const std::string &Label) {
+    std::string Str(Label);
+    for (unsigned i = 0; i != Str.length(); ++i)
+      switch (Str[i]) {
+      case '\n':
+        Str.insert(Str.begin()+i, '\\');  // Escape character...
+        ++i;
+        Str[i] = 'n';
+        break;
+      case '\t':
+        Str.insert(Str.begin()+i, ' ');  // Convert to two spaces
+        ++i;
+        Str[i] = ' ';
+        break;
+      case '\\':
+        if (i+1 != Str.length() && Str[i+1] == 'l')
+          break;  // don't disturb \l
+      case '{': case '}':
+      case '<': case '>':
+        Str.insert(Str.begin()+i, '\\');  // Escape character...
+        ++i;  // don't infinite loop
+        break;
+      }
+    return Str;
+  }
+}
+
+template<typename GraphType>
+std::ostream &WriteGraph(std::ostream &O, const GraphType &G) {
+  typedef DOTGraphTraits<GraphType>  DOTTraits;
+  typedef GraphTraits<GraphType>     GTraits;
+  typedef typename GTraits::NodeType NodeType;
+
+  O << "digraph foo {\n"         // Graph name doesn't matter
+    << "\tsize=\"10,7.5\";\n"    // Size to fit on a page
+    << "\trotate=\"90\";\n";     // Orient correctly
+
+  std::string GraphName = DOTTraits::getGraphName(G);
+  if (!GraphName.empty())
+    O << "\tlabel=\"" << DOT::EscapeString(GraphName) << "\";\n";
+  O << "\n";
+
+  // Loop over the graph in DFO, printing it out...
+  NodeType *Root = GTraits::getEntryNode(G);
+  for (df_iterator<GraphType> I = df_begin(G), E = df_end(G); I != E; ++I) {
+    NodeType *Node = *I;
+
+    std::string NodeAttributes = DOTTraits::getNodeAttributes(Node);
+
+    O << "\tNode" << (void*)Node << " [";
+    if (!NodeAttributes.empty()) O << NodeAttributes << ",";
+    O << "shape=record,label=\"{"
+      << DOT::EscapeString(DOTTraits::getNodeLabel(Node, G));
+    
+    // Print out the fields of the current node...
+    typename GTraits::ChildIteratorType EI = GTraits::child_begin(Node);
+    typename GTraits::ChildIteratorType EE = GTraits::child_end(Node);
+    if (EI != EE) {
+      O << "|{";
+
+      for (unsigned i = 0; EI != EE && i != 64; ++EI, ++i) {
+        if (i) O << "|";
+        O << "<g" << i << ">" << DOTTraits::getEdgeSourceLabel(Node, EI);
+      }
+
+      if (EI != EE)
+        O << "|truncated...";
+      O << "}";
+    }
+    O << "}\"];\n";   // Finish printing the "node" line
+
+    // Output all of the edges now
+    EI = GTraits::child_begin(Node);
+    for (unsigned i = 0; EI != EE && i != 64; ++EI, ++i) {
+      NodeType *TargetNode = *EI;
+      O << "\tNode" << (void*)Node << ":g" << i << " -> Node"
+        << (void*)TargetNode;
+      if (DOTTraits::edgeTargetsEdgeSource(Node, EI)) {
+        typename GTraits::ChildIteratorType TargetIt =
+          DOTTraits::getEdgeTarget(Node, EI);
+        // Figure out which edge this targets...
+        unsigned Offset = std::distance(GTraits::child_begin(TargetNode),
+                                        TargetIt);
+        if (Offset > 64) Offset = 64;  // Targetting the trancated part?
+        O << ":g" << Offset;        
+      }
+
+      std::string EdgeAttributes = DOTTraits::getEdgeAttributes(Node, EI);
+      if (!EdgeAttributes.empty())
+        O << "[" << EdgeAttributes << "]";
+      O << ";\n";
+    }
+  }
+
+  // Finish off the graph
+  O << "}\n";
+  return O;
+}
+
+#endif