[llvm-commits] CVS: llvm/lib/Analysis/CFGPrinter.cpp

[Chris Lattner]

Changes in directory llvm/lib/Analysis:

CFGPrinter.cpp added (r1.1)

---
Log message:

Implement the Function::viewCFG* methods, for use in a debugger.  Also, the
-print-cfg pass now lives here.


---
Diffs of the changes:  (+144 -0)

Index: llvm/lib/Analysis/CFGPrinter.cpp
diff -c /dev/null llvm/lib/Analysis/CFGPrinter.cpp:1.1
*** /dev/null	Wed Oct 22 11:03:59 2003
--- llvm/lib/Analysis/CFGPrinter.cpp	Wed Oct 22 11:03:49 2003
***************
*** 0 ****
--- 1,144 ----
+ //===- CFGPrinter.cpp - DOT printer for the control flow graph ------------===//
+ // 
+ //                     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 file defines a '-print-cfg' analysis pass, which emits the
+ // cfg.<fnname>.dot file for each function in the program, with a graph of the
+ // CFG for that function.
+ //
+ // The other main feature of this file is that it implements the
+ // Function::viewCFG method, which is useful for debugging passes which operate
+ // on the CFG.
+ //
+ //===----------------------------------------------------------------------===//
+ 
+ #include "Support/GraphWriter.h"
+ #include "llvm/Pass.h"
+ #include "llvm/Function.h"
+ #include "llvm/iTerminators.h"
+ #include "llvm/Support/CFG.h"
+ #include <sstream>
+ #include <fstream>
+ 
+ /// CFGOnly flag - This is used to control whether or not the CFG graph printer
+ /// prints out the contents of basic blocks or not.  This is acceptable because
+ /// this code is only really used for debugging purposes.
+ ///
+ static bool CFGOnly = false;
+ 
+ template<>
+ struct DOTGraphTraits<const Function*> : public DefaultDOTGraphTraits {
+   static std::string getGraphName(const Function *F) {
+     return "CFG for '" + F->getName() + "' function";
+   }
+ 
+   static std::string getNodeLabel(const BasicBlock *Node,
+                                   const Function *Graph) {
+     if (CFGOnly) return Node->getName() + ":";
+ 
+     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(const BasicBlock *N) {
+     return "fontname=Courier";
+   }
+   
+   static std::string getEdgeSourceLabel(const BasicBlock *Node,
+                                         succ_const_iterator I) {
+     // Label source of conditional branches with "T" or "F"
+     if (const BranchInst *BI = dyn_cast<BranchInst>(Node->getTerminator()))
+       if (BI->isConditional())
+         return (I == succ_begin(Node)) ? "T" : "F";
+     return "";
+   }
+ };
+ 
+ namespace {
+   struct CFGPrinter : public FunctionPass {
+     virtual bool runOnFunction(Function &F) {
+       std::string Filename = "cfg." + F.getName() + ".dot";
+       std::cerr << "Writing '" << Filename << "'...";
+       std::ofstream File(Filename.c_str());
+       
+       if (File.good())
+         WriteGraph(File, (const Function*)&F);
+       else
+         std::cerr << "  error opening file for writing!";
+       std::cerr << "\n";
+       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");
+ };
+ 
+ 
+ 
+ 
+ /// viewCFG - This function is meant for use from the debugger.  You can just
+ /// say 'call F->viewCFG()' and a ghostview window should pop up from the
+ /// program, displaying the CFG of the current function.  This depends on there
+ /// being a 'dot' and 'gv' program in your path.
+ ///
+ void Function::viewCFG() const {
+   std::string Filename = "/tmp/cfg." + getName() + ".dot";
+   std::cerr << "Writing '" << Filename << "'... ";
+   std::ofstream F(Filename.c_str());
+   
+   if (!F.good()) {
+     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 " + Filename + " > /tmp/cfg.tempgraph.ps").c_str())) {
+     std::cerr << "Error running dot: 'dot' not in path?\n";
+   } else {
+     std::cerr << "\n";
+     system("gv /tmp/cfg.tempgraph.ps");
+   }
+   system(("rm " + Filename + " /tmp/cfg.tempgraph.ps").c_str());
+ }
+ 
+ /// viewCFGOnly - This function is meant for use from the debugger.  It works
+ /// just like viewCFG, but it does not include the contents of basic blocks
+ /// into the nodes, just the label.  If you are only interested in the CFG t
+ /// his can make the graph smaller.
+ ///
+ void Function::viewCFGOnly() const {
+   CFGOnly = true;
+   viewCFG();
+   CFGOnly = false;
+ }