- Implement a new -print-cfg option for analyze, that causes it to print the

    CFG of each function in the module to 'dot' files.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@4062 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 88 insertions, 0 deletions

diff --git a/tools/opt/GraphPrinters.cpp b/tools/opt/GraphPrinters.cpp
new file mode 100644
index 0000000000..35bff565a1
--- /dev/null
+++ b/tools/opt/GraphPrinters.cpp
@@ -0,0 +1,88 @@
+//===- GraphPrinters.cpp - DOT printers for various graph types -----------===//
+//
+// This file defines several printers for various different types of graphs used
+// by the LLVM infrastructure.  It uses the generic graph interface to convert
+// the graph into a .dot graph.  These graphs can then be processed with the
+// "dot" tool to convert them to postscript or some other suitable format.
+//
+//===----------------------------------------------------------------------===//
+
+#include "Support/GraphWriter.h"
+#include "llvm/Pass.h"
+#include "llvm/iTerminators.h"
+#include "llvm/Support/CFG.h"
+#include <sstream>
+#include <fstream>
+
+template<>
+struct DOTGraphTraits<Function*> : public DefaultDOTGraphTraits {
+  static std::string getGraphName(Function *F) {
+    return "CFG for '" + F->getName() + "' function";
+  }
+
+  static std::string getNodeLabel(BasicBlock *Node, Function *Graph) {
+    std::ostringstream Out;
+    Out << Node;
+    std::string OutStr = Out.str();
+    if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());
+
+    // Process string output to make it nicer...
+    for (unsigned i = 0; i != OutStr.length(); ++i)
+      if (OutStr[i] == '\n') {                            // Left justify
+        OutStr[i] = '\\';
+        OutStr.insert(OutStr.begin()+i+1, 'l');
+      } else if (OutStr[i] == ';') {                      // Delete comments!
+        unsigned Idx = OutStr.find('\n', i+1);            // Find end of line
+        OutStr.erase(OutStr.begin()+i, OutStr.begin()+Idx);
+        --i;
+      }
+
+    return OutStr;
+  }
+
+  static std::string getNodeAttributes(BasicBlock *N) {
+    return "fontname=Courier";
+  }
+  
+  static std::string getEdgeSourceLabel(BasicBlock *Node, succ_iterator I) {
+    // Label source of conditional branches with "T" or "F"
+    if (BranchInst *BI = dyn_cast<BranchInst>(Node->getTerminator()))
+      if (BI->isConditional())
+        return (I == succ_begin(Node)) ? "T" : "F";
+    return "";
+  }
+};
+
+template<typename GraphType>
+static void WriteGraphToFile(std::ostream &O, const std::string &GraphName,
+                             const GraphType &GT) {
+  std::string Filename = GraphName + ".dot";
+  O << "Writing '" << Filename << "'...";
+  std::ofstream F(Filename.c_str());
+  
+  if (F.good())
+    WriteGraph(F, GT);
+  else
+    O << "  error opening file for writing!";
+  O << "\n";
+}
+
+
+namespace {
+  struct CFGPrinter : public FunctionPass {
+    Function *F;
+    virtual bool runOnFunction(Function &Func) {
+      WriteGraphToFile(std::cerr, "cfg."+Func.getName(), &Func);
+      return false;
+    }
+
+    void print(std::ostream &OS) const {}
+    
+    virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+      AU.setPreservesAll();
+    }
+  };
+
+  RegisterAnalysis<CFGPrinter> P1("print-cfg",
+                                  "Print CFG of function to 'dot' file");
+};