tools/bugpoint/Miscompilation.cpp - platform/external/llvm - Gitiles

 //===- Miscompilation.cpp - Debug program miscompilations -----------------===//
 //
 // This file implements program miscompilation debugging support.
 //
 //===----------------------------------------------------------------------===//

 #include "BugDriver.h"
 #include "ListReducer.h"
 #include "llvm/Module.h"
 #include "llvm/Pass.h"
 #include "llvm/Transforms/Utils/Cloning.h"
 #include "llvm/Transforms/Utils/Linker.h"
 #include "Support/FileUtilities.h"

 class ReduceMiscompilingPasses : public ListReducer<const PassInfo*> {
   BugDriver &BD;
 public:
   ReduceMiscompilingPasses(BugDriver &bd) : BD(bd) {}

   virtual TestResult doTest(std::vector<const PassInfo*> &Prefix,
                             std::vector<const PassInfo*> &Suffix);
 };

 ReduceMiscompilingPasses::TestResult
 ReduceMiscompilingPasses::doTest(std::vector<const PassInfo*> &Prefix,
                                  std::vector<const PassInfo*> &Suffix) {
   // First, run the program with just the Suffix passes.  If it is still broken
   // with JUST the kept passes, discard the prefix passes.
   std::cout << "Checking to see if '" << getPassesString(Suffix)
             << "' compile correctly: ";

   std::string BytecodeResult;
   if (BD.runPasses(Suffix, BytecodeResult, false/*delete*/, true/*quiet*/)) {
     std::cerr << ": Error running this sequence of passes"
               << " on the input program!\n";
     BD.setPassesToRun(Suffix);
     BD.EmitProgressBytecode("pass-error",  false);
     exit(1);
   }

   // Check to see if the finished program matches the reference output...
   if (BD.diffProgram(BytecodeResult, "", true /*delete bytecode*/)) {
     std::cout << "nope.\n";
     return KeepSuffix;        // Miscompilation detected!
   }
   std::cout << "yup.\n";      // No miscompilation!

   if (Prefix.empty()) return NoFailure;

   // Next, see if the program is broken if we run the "prefix" passes first,
   // then separately run the "kept" passes.
   std::cout << "Checking to see if '" << getPassesString(Prefix)
             << "' compile correctly: ";

   // If it is not broken with the kept passes, it's possible that the prefix
   // passes must be run before the kept passes to break it.  If the program
   // WORKS after the prefix passes, but then fails if running the prefix AND
   // kept passes, we can update our bytecode file to include the result of the
   // prefix passes, then discard the prefix passes.
   //
   if (BD.runPasses(Prefix, BytecodeResult, false/*delete*/, true/*quiet*/)) {
     std::cerr << ": Error running this sequence of passes"
               << " on the input program!\n";
     BD.setPassesToRun(Prefix);
     BD.EmitProgressBytecode("pass-error",  false);
     exit(1);
   }

   // If the prefix maintains the predicate by itself, only keep the prefix!
   if (BD.diffProgram(BytecodeResult)) {
     std::cout << "nope.\n";
     removeFile(BytecodeResult);
     return KeepPrefix;
   }
   std::cout << "yup.\n";      // No miscompilation!

   // Ok, so now we know that the prefix passes work, try running the suffix
   // passes on the result of the prefix passes.
   //
   Module *PrefixOutput = BD.ParseInputFile(BytecodeResult);
   if (PrefixOutput == 0) {
     std::cerr << BD.getToolName() << ": Error reading bytecode file '"
               << BytecodeResult << "'!\n";
     exit(1);
   }
   removeFile(BytecodeResult);  // No longer need the file on disk

   std::cout << "Checking to see if '" << getPassesString(Suffix)
             << "' passes compile correctly after the '"
             << getPassesString(Prefix) << "' passes: ";

   Module *OriginalInput = BD.Program;
   BD.Program = PrefixOutput;
   if (BD.runPasses(Suffix, BytecodeResult, false/*delete*/, true/*quiet*/)) {
     std::cerr << ": Error running this sequence of passes"
               << " on the input program!\n";
     BD.setPassesToRun(Suffix);
     BD.EmitProgressBytecode("pass-error",  false);
     exit(1);
   }

   // Run the result...
   if (BD.diffProgram(BytecodeResult, "", true/*delete bytecode*/)) {
     std::cout << "nope.\n";
     delete OriginalInput;     // We pruned down the original input...
     return KeepSuffix;
   }

   // Otherwise, we must not be running the bad pass anymore.
   std::cout << "yup.\n";      // No miscompilation!
   BD.Program = OriginalInput; // Restore original program
   delete PrefixOutput;        // Free experiment
   return NoFailure;
 }

 class ReduceMiscompilingFunctions : public ListReducer<Function*> {
   BugDriver &BD;
 public:
   ReduceMiscompilingFunctions(BugDriver &bd) : BD(bd) {}

   virtual TestResult doTest(std::vector<Function*> &Prefix,
                             std::vector<Function*> &Suffix) {
     if (!Suffix.empty() && TestFuncs(Suffix, false))
       return KeepSuffix;
     if (!Prefix.empty() && TestFuncs(Prefix, false))
       return KeepPrefix;
     return NoFailure;
   }

   bool TestFuncs(const std::vector<Function*> &Prefix, bool EmitBytecode);
 };

 bool ReduceMiscompilingFunctions::TestFuncs(const std::vector<Function*> &Funcs,
                                             bool EmitBytecode) {
   // Test to see if the function is misoptimized if we ONLY run it on the
   // functions listed in Funcs.
   if (!EmitBytecode) {
     std::cout << "Checking to see if the program is misoptimized when these "
               << "functions are run\nthrough the passes: ";
     BD.PrintFunctionList(Funcs);
     std::cout << "\n";
   } else {
     std::cout <<"Outputting reduced bytecode files which expose the problem:\n";
   }

   // First step: clone the module for the two halves of the program we want.
   Module *ToOptimize = CloneModule(BD.Program);

   // Second step: Make sure functions & globals are all external so that linkage
   // between the two modules will work.
   for (Module::iterator I = ToOptimize->begin(), E = ToOptimize->end();I!=E;++I)
     I->setLinkage(GlobalValue::ExternalLinkage);
   for (Module::giterator I = ToOptimize->gbegin(), E = ToOptimize->gend();
        I != E; ++I)
     I->setLinkage(GlobalValue::ExternalLinkage);

   // Third step: make a clone of the externalized program for the non-optimized
   // part.
   Module *ToNotOptimize = CloneModule(ToOptimize);

   // Fourth step: Remove the test functions from the ToNotOptimize module, and
   // all of the global variables.
   for (unsigned i = 0, e = Funcs.size(); i != e; ++i) {
     Function *TNOF = ToNotOptimize->getFunction(Funcs[i]->getName(),
                                                 Funcs[i]->getFunctionType());
     assert(TNOF && "Function doesn't exist in module!");
     DeleteFunctionBody(TNOF);       // Function is now external in this module!
   }
   for (Module::giterator I = ToNotOptimize->gbegin(), E = ToNotOptimize->gend();
        I != E; ++I)
     I->setInitializer(0);  // Delete the initializer to make it external

   if (EmitBytecode) {
     std::cout << "  Non-optimized portion: ";
     std::swap(BD.Program, ToNotOptimize);
     BD.EmitProgressBytecode("tonotoptimize", true);
     std::swap(BD.Program, ToNotOptimize);
   }

   // Fifth step: Remove all functions from the ToOptimize module EXCEPT for the
   // ones specified in Funcs.  We know which ones these are because they are
   // non-external in ToOptimize, but external in ToNotOptimize.
   //
   for (Module::iterator I = ToOptimize->begin(), E = ToOptimize->end();I!=E;++I)
     if (!I->isExternal()) {
       Function *TNOF = ToNotOptimize->getFunction(I->getName(),
                                                   I->getFunctionType());
       assert(TNOF && "Function doesn't exist in ToNotOptimize module??");
       if (!TNOF->isExternal())
         DeleteFunctionBody(I);
     }

   if (EmitBytecode) {
     std::cout << "  Portion that is input to optimizer: ";
     std::swap(BD.Program, ToOptimize);
     BD.EmitProgressBytecode("tooptimize");
     std::swap(BD.Program, ToOptimize);
   }

   // Sixth step: Run the optimization passes on ToOptimize, producing a
   // transformed version of the functions being tested.
   Module *OldProgram = BD.Program;
   BD.Program = ToOptimize;

   if (!EmitBytecode)
     std::cout << "  Optimizing functions being tested: ";
   std::string BytecodeResult;
   if (BD.runPasses(BD.PassesToRun, BytecodeResult, false/*delete*/,
                    true/*quiet*/)) {
     std::cerr << ": Error running this sequence of passes"
               << " on the input program!\n";
     BD.setPassesToRun(Suffix);
     BD.EmitProgressBytecode("pass-error",  false);
     exit(1);
   }

   if (!EmitBytecode)
     std::cout << "done.\n";

   delete BD.Program;   // Delete the old "ToOptimize" module
   BD.Program = BD.ParseInputFile(BytecodeResult);

   if (EmitBytecode) {
     std::cout << "  'tooptimize' after being optimized: ";
     BD.EmitProgressBytecode("optimized", true);
   }

   if (BD.Program == 0) {
     std::cerr << BD.getToolName() << ": Error reading bytecode file '"
               << BytecodeResult << "'!\n";
     exit(1);
   }
   removeFile(BytecodeResult);  // No longer need the file on disk

   // Seventh step: Link the optimized part of the program back to the
   // unoptimized part of the program.
   //
   if (LinkModules(BD.Program, ToNotOptimize, &BytecodeResult)) {
     std::cerr << BD.getToolName() << ": Error linking modules together:"
               << BytecodeResult << "\n";
     exit(1);
   }
   delete ToNotOptimize;  // We are done with this module...

   if (EmitBytecode) {
     std::cout << "  Program as tested: ";
     BD.EmitProgressBytecode("linked", true);
     delete BD.Program;
     BD.Program = OldProgram;
     return false;   // We don't need to actually execute the program here.
   }

   std::cout << "  Checking to see if the merged program executes correctly: ";

   // Eighth step: Execute the program.  If it does not match the expected
   // output, then 'Funcs' are being misoptimized!
   bool Broken = BD.diffProgram();

   delete BD.Program;  // Delete the hacked up program
   BD.Program = OldProgram;   // Restore the original

   std::cout << (Broken ? "nope.\n" : "yup.\n");
   return Broken;
 }


 /// debugMiscompilation - This method is used when the passes selected are not
 /// crashing, but the generated output is semantically different from the
 /// input.
 ///
 bool BugDriver::debugMiscompilation() {
   // Make sure something was miscompiled...
   if (!ReduceMiscompilingPasses(*this).reduceList(PassesToRun)) {
     std::cerr << "*** Optimized program matches reference output!  No problem "
 	      << "detected...\nbugpoint can't help you with your problem!\n";
     return false;
   }

   std::cout << "\n*** Found miscompiling pass"
             << (PassesToRun.size() == 1 ? "" : "es") << ": "
             << getPassesString(PassesToRun) << "\n";
   EmitProgressBytecode("passinput");

   // Okay, now that we have reduced the list of passes which are causing the
   // failure, see if we can pin down which functions are being
   // miscompiled... first build a list of all of the non-external functions in
   // the program.
   std::vector<Function*> MiscompiledFunctions;
   for (Module::iterator I = Program->begin(), E = Program->end(); I != E; ++I)
     if (!I->isExternal())
       MiscompiledFunctions.push_back(I);

   // Do the reduction...
   ReduceMiscompilingFunctions(*this).reduceList(MiscompiledFunctions);

   std::cout << "\n*** The following functions are being miscompiled: ";
   PrintFunctionList(MiscompiledFunctions);
   std::cout << "\n";

   // Output a bunch of bytecode files for the user...
   ReduceMiscompilingFunctions(*this).TestFuncs(MiscompiledFunctions, true);

   return false;
 }
	//===- Miscompilation.cpp - Debug program miscompilations -----------------===//
	//
	// This file implements program miscompilation debugging support.
	//
	//===----------------------------------------------------------------------===//

	#include "BugDriver.h"
	#include "ListReducer.h"
	#include "llvm/Module.h"
	#include "llvm/Pass.h"
	#include "llvm/Transforms/Utils/Cloning.h"
	#include "llvm/Transforms/Utils/Linker.h"
	#include "Support/FileUtilities.h"

	class ReduceMiscompilingPasses : public ListReducer<const PassInfo*> {
	BugDriver &BD;
	public:
	ReduceMiscompilingPasses(BugDriver &bd) : BD(bd) {}

	virtual TestResult doTest(std::vector<const PassInfo*> &Prefix,
	std::vector<const PassInfo*> &Suffix);
	};

	ReduceMiscompilingPasses::TestResult
	ReduceMiscompilingPasses::doTest(std::vector<const PassInfo*> &Prefix,
	std::vector<const PassInfo*> &Suffix) {
	// First, run the program with just the Suffix passes. If it is still broken
	// with JUST the kept passes, discard the prefix passes.
	std::cout << "Checking to see if '" << getPassesString(Suffix)
	<< "' compile correctly: ";

	std::string BytecodeResult;
	if (BD.runPasses(Suffix, BytecodeResult, false/delete/, true/quiet/)) {
	std::cerr << ": Error running this sequence of passes"
	<< " on the input program!\n";
	BD.setPassesToRun(Suffix);
	BD.EmitProgressBytecode("pass-error", false);
	exit(1);
	}

	// Check to see if the finished program matches the reference output...
	if (BD.diffProgram(BytecodeResult, "", true /delete bytecode/)) {
	std::cout << "nope.\n";
	return KeepSuffix; // Miscompilation detected!
	}
	std::cout << "yup.\n"; // No miscompilation!

	if (Prefix.empty()) return NoFailure;

	// Next, see if the program is broken if we run the "prefix" passes first,
	// then separately run the "kept" passes.
	std::cout << "Checking to see if '" << getPassesString(Prefix)
	<< "' compile correctly: ";

	// If it is not broken with the kept passes, it's possible that the prefix
	// passes must be run before the kept passes to break it. If the program
	// WORKS after the prefix passes, but then fails if running the prefix AND
	// kept passes, we can update our bytecode file to include the result of the
	// prefix passes, then discard the prefix passes.
	//
	if (BD.runPasses(Prefix, BytecodeResult, false/delete/, true/quiet/)) {
	std::cerr << ": Error running this sequence of passes"
	<< " on the input program!\n";
	BD.setPassesToRun(Prefix);
	BD.EmitProgressBytecode("pass-error", false);
	exit(1);
	}

	// If the prefix maintains the predicate by itself, only keep the prefix!
	if (BD.diffProgram(BytecodeResult)) {
	std::cout << "nope.\n";
	removeFile(BytecodeResult);
	return KeepPrefix;
	}
	std::cout << "yup.\n"; // No miscompilation!

	// Ok, so now we know that the prefix passes work, try running the suffix
	// passes on the result of the prefix passes.
	//
	Module *PrefixOutput = BD.ParseInputFile(BytecodeResult);
	if (PrefixOutput == 0) {
	std::cerr << BD.getToolName() << ": Error reading bytecode file '"
	<< BytecodeResult << "'!\n";
	exit(1);
	}
	removeFile(BytecodeResult); // No longer need the file on disk

	std::cout << "Checking to see if '" << getPassesString(Suffix)
	<< "' passes compile correctly after the '"
	<< getPassesString(Prefix) << "' passes: ";

	Module *OriginalInput = BD.Program;
	BD.Program = PrefixOutput;
	if (BD.runPasses(Suffix, BytecodeResult, false/delete/, true/quiet/)) {
	std::cerr << ": Error running this sequence of passes"
	<< " on the input program!\n";
	BD.setPassesToRun(Suffix);
	BD.EmitProgressBytecode("pass-error", false);
	exit(1);
	}

	// Run the result...
	if (BD.diffProgram(BytecodeResult, "", true/delete bytecode/)) {
	std::cout << "nope.\n";
	delete OriginalInput; // We pruned down the original input...
	return KeepSuffix;
	}

	// Otherwise, we must not be running the bad pass anymore.
	std::cout << "yup.\n"; // No miscompilation!
	BD.Program = OriginalInput; // Restore original program
	delete PrefixOutput; // Free experiment
	return NoFailure;
	}

	class ReduceMiscompilingFunctions : public ListReducer<Function*> {
	BugDriver &BD;
	public:
	ReduceMiscompilingFunctions(BugDriver &bd) : BD(bd) {}

	virtual TestResult doTest(std::vector<Function*> &Prefix,
	std::vector<Function*> &Suffix) {
	if (!Suffix.empty() && TestFuncs(Suffix, false))
	return KeepSuffix;
	if (!Prefix.empty() && TestFuncs(Prefix, false))
	return KeepPrefix;
	return NoFailure;
	}

	bool TestFuncs(const std::vector<Function*> &Prefix, bool EmitBytecode);
	};

	bool ReduceMiscompilingFunctions::TestFuncs(const std::vector<Function*> &Funcs,
	bool EmitBytecode) {
	// Test to see if the function is misoptimized if we ONLY run it on the
	// functions listed in Funcs.
	if (!EmitBytecode) {
	std::cout << "Checking to see if the program is misoptimized when these "
	<< "functions are run\nthrough the passes: ";
	BD.PrintFunctionList(Funcs);
	std::cout << "\n";
	} else {
	std::cout <<"Outputting reduced bytecode files which expose the problem:\n";
	}

	// First step: clone the module for the two halves of the program we want.
	Module *ToOptimize = CloneModule(BD.Program);

	// Second step: Make sure functions & globals are all external so that linkage
	// between the two modules will work.
	for (Module::iterator I = ToOptimize->begin(), E = ToOptimize->end();I!=E;++I)
	I->setLinkage(GlobalValue::ExternalLinkage);
	for (Module::giterator I = ToOptimize->gbegin(), E = ToOptimize->gend();
	I != E; ++I)
	I->setLinkage(GlobalValue::ExternalLinkage);

	// Third step: make a clone of the externalized program for the non-optimized
	// part.
	Module *ToNotOptimize = CloneModule(ToOptimize);

	// Fourth step: Remove the test functions from the ToNotOptimize module, and
	// all of the global variables.
	for (unsigned i = 0, e = Funcs.size(); i != e; ++i) {
	Function *TNOF = ToNotOptimize->getFunction(Funcs[i]->getName(),
	Funcs[i]->getFunctionType());
	assert(TNOF && "Function doesn't exist in module!");
	DeleteFunctionBody(TNOF); // Function is now external in this module!
	}
	for (Module::giterator I = ToNotOptimize->gbegin(), E = ToNotOptimize->gend();
	I != E; ++I)
	I->setInitializer(0); // Delete the initializer to make it external

	if (EmitBytecode) {
	std::cout << " Non-optimized portion: ";
	std::swap(BD.Program, ToNotOptimize);
	BD.EmitProgressBytecode("tonotoptimize", true);
	std::swap(BD.Program, ToNotOptimize);
	}

	// Fifth step: Remove all functions from the ToOptimize module EXCEPT for the
	// ones specified in Funcs. We know which ones these are because they are
	// non-external in ToOptimize, but external in ToNotOptimize.
	//
	for (Module::iterator I = ToOptimize->begin(), E = ToOptimize->end();I!=E;++I)
	if (!I->isExternal()) {
	Function *TNOF = ToNotOptimize->getFunction(I->getName(),
	I->getFunctionType());
	assert(TNOF && "Function doesn't exist in ToNotOptimize module??");
	if (!TNOF->isExternal())
	DeleteFunctionBody(I);
	}

	if (EmitBytecode) {
	std::cout << " Portion that is input to optimizer: ";
	std::swap(BD.Program, ToOptimize);
	BD.EmitProgressBytecode("tooptimize");
	std::swap(BD.Program, ToOptimize);
	}

	// Sixth step: Run the optimization passes on ToOptimize, producing a
	// transformed version of the functions being tested.
	Module *OldProgram = BD.Program;
	BD.Program = ToOptimize;

	if (!EmitBytecode)
	std::cout << " Optimizing functions being tested: ";
	std::string BytecodeResult;
	if (BD.runPasses(BD.PassesToRun, BytecodeResult, false/delete/,
	true/quiet/)) {
	std::cerr << ": Error running this sequence of passes"
	<< " on the input program!\n";
	BD.setPassesToRun(Suffix);
	BD.EmitProgressBytecode("pass-error", false);
	exit(1);
	}

	if (!EmitBytecode)
	std::cout << "done.\n";

	delete BD.Program; // Delete the old "ToOptimize" module
	BD.Program = BD.ParseInputFile(BytecodeResult);

	if (EmitBytecode) {
	std::cout << " 'tooptimize' after being optimized: ";
	BD.EmitProgressBytecode("optimized", true);
	}

	if (BD.Program == 0) {
	std::cerr << BD.getToolName() << ": Error reading bytecode file '"
	<< BytecodeResult << "'!\n";
	exit(1);
	}
	removeFile(BytecodeResult); // No longer need the file on disk

	// Seventh step: Link the optimized part of the program back to the
	// unoptimized part of the program.
	//
	if (LinkModules(BD.Program, ToNotOptimize, &BytecodeResult)) {
	std::cerr << BD.getToolName() << ": Error linking modules together:"
	<< BytecodeResult << "\n";
	exit(1);
	}
	delete ToNotOptimize; // We are done with this module...

	if (EmitBytecode) {
	std::cout << " Program as tested: ";
	BD.EmitProgressBytecode("linked", true);
	delete BD.Program;
	BD.Program = OldProgram;
	return false; // We don't need to actually execute the program here.
	}

	std::cout << " Checking to see if the merged program executes correctly: ";

	// Eighth step: Execute the program. If it does not match the expected
	// output, then 'Funcs' are being misoptimized!
	bool Broken = BD.diffProgram();

	delete BD.Program; // Delete the hacked up program
	BD.Program = OldProgram; // Restore the original

	std::cout << (Broken ? "nope.\n" : "yup.\n");
	return Broken;
	}


	/// debugMiscompilation - This method is used when the passes selected are not
	/// crashing, but the generated output is semantically different from the
	/// input.
	///
	bool BugDriver::debugMiscompilation() {
	// Make sure something was miscompiled...
	if (!ReduceMiscompilingPasses(*this).reduceList(PassesToRun)) {
	std::cerr << "*** Optimized program matches reference output! No problem "
	<< "detected...\nbugpoint can't help you with your problem!\n";
	return false;
	}

	std::cout << "\n*** Found miscompiling pass"
	<< (PassesToRun.size() == 1 ? "" : "es") << ": "
	<< getPassesString(PassesToRun) << "\n";
	EmitProgressBytecode("passinput");

	// Okay, now that we have reduced the list of passes which are causing the
	// failure, see if we can pin down which functions are being
	// miscompiled... first build a list of all of the non-external functions in
	// the program.
	std::vector<Function*> MiscompiledFunctions;
	for (Module::iterator I = Program->begin(), E = Program->end(); I != E; ++I)
	if (!I->isExternal())
	MiscompiledFunctions.push_back(I);

	// Do the reduction...
	ReduceMiscompilingFunctions(*this).reduceList(MiscompiledFunctions);

	std::cout << "\n*** The following functions are being miscompiled: ";
	PrintFunctionList(MiscompiledFunctions);
	std::cout << "\n";

	// Output a bunch of bytecode files for the user...
	ReduceMiscompilingFunctions(*this).TestFuncs(MiscompiledFunctions, true);

	return false;
	}