//===- Miscompilation.cpp - Debug program miscompilations -----------------===//
+//
+// 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 implements program miscompilation debugging support.
//
//===----------------------------------------------------------------------===//
#include "BugDriver.h"
-#include "SystemUtils.h"
-#include "llvm/Pass.h"
+#include "ListReducer.h"
#include "llvm/Module.h"
-#include "Support/CommandLine.h"
+#include "llvm/Pass.h"
+#include "llvm/Transforms/Utils/Cloning.h"
+#include "llvm/Transforms/Utils/Linker.h"
+#include "Support/FileUtilities.h"
+using namespace llvm;
-// Anonymous namespace to define command line options for miscompilation
-// debugging.
-//
-namespace {
- // Output - The user can specify a file containing the expected output of the
- // program. If this filename is set, it is used as the reference diff source,
- // otherwise the raw input run through an interpreter is used as the reference
- // source.
- //
- cl::opt<std::string>
- Output("output", cl::desc("Specify a reference program output "
- "(for miscompilation detection)"));
+namespace llvm {
+
+ 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);
+ };
}
-/// 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() {
- std::cout << "*** Debugging miscompilation!\n";
+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(BD.debugOptimizerCrash());
+ }
- // Set up the execution environment, selecting a method to run LLVM bytecode.
- if (initializeExecutionEnvironment()) return true;
+ // 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: ";
- // Run the raw input to see where we are coming from. If a reference output
- // was specified, make sure that the raw output matches it. If not, it's a
- // problem in the front-end or whatever produced the input code.
+ // 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.
//
- bool CreatedOutput = false;
- if (Output.empty()) {
- std::cout << "Generating reference output from raw program...";
- Output = executeProgram("bugpoint.reference.out");
- CreatedOutput = true;
- std::cout << " done!\n";
- } else if (diffProgram(Output)) {
- std::cout << "\n*** Input program does not match reference diff!\n"
- << " Must be problem with input source!\n";
- return false; // Problem found
- }
-
- // Figure out which transformation is the first to miscompile the input
- // program. We do a binary search here in case there are a large number of
- // passes involved.
+ 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(BD.debugOptimizerCrash());
+ }
+
+ // 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.
//
- unsigned LastGood = 0, LastBad = PassesToRun.size();
- while (LastGood != LastBad) {
- unsigned Mid = (LastBad+LastGood+1) / 2;
- std::vector<const PassInfo*> P(PassesToRun.begin(),
- PassesToRun.begin()+Mid);
- std::cout << "Checking to see if the first " << Mid << " passes are ok: ";
-
- std::string BytecodeResult;
- if (runPasses(P, BytecodeResult, false, true)) {
- std::cerr << ToolName << ": Error running this sequence of passes"
- << " on the input program!\n";
- exit(1);
+ 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(BD.debugOptimizerCrash());
+ }
+
+ // 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;
+}
+
+namespace llvm {
+ 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 "
+ << (Funcs.size()==1 ? "this function is" : "these functions are")
+ << " run through the pass"
+ << (BD.PassesToRun.size() == 1 ? "" : "es") << ": ";
+ 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.getProgram());
+
+ // 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);
- // Check to see if the finished program matches the reference output...
- if (diffProgram(Output, BytecodeResult)) {
- std::cout << "nope.\n";
- LastBad = Mid-1; // Miscompilation detected!
- } else {
- std::cout << "yup.\n";
- LastGood = Mid; // No miscompilation!
+ // 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);
}
- // We are now done with the optimized output... so remove it.
- removeFile(BytecodeResult);
+ 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.EmitProgressBytecode("pass-error", false);
+ exit(BD.debugOptimizerCrash());
+ }
+
+ if (!EmitBytecode)
+ std::cout << "done.\n";
+
+ delete BD.getProgram(); // 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 (LastBad >= PassesToRun.size()) {
+ 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;
}
- // Calculate which pass it is that miscompiles...
- const PassInfo *ThePass = PassesToRun[LastBad];
-
- std::cout << "\n*** Found miscompiling pass '-" << ThePass->getPassArgument()
- << "': " << ThePass->getPassName() << "\n";
-
- if (LastGood != 0) {
- std::vector<const PassInfo*> P(PassesToRun.begin(),
- PassesToRun.begin()+LastGood);
- std::string Filename;
- std::cout << "Running good passes to get input for pass:";
- if (runPasses(P, Filename, false, true)) {
- std::cerr << "ERROR: Running the first " << LastGood
- << " passes crashed!\n";
- return true;
- }
- std::cout << " done!\n";
-
- // Assuming everything was successful, we now have a valid bytecode file in
- // OutputName. Use it for "Program" Instead.
- delete Program;
- Program = ParseInputFile(Filename);
-
- // Delete the file now.
- removeFile(Filename);
- }
+ std::cout << "\n*** Found miscompiling pass"
+ << (PassesToRun.size() == 1 ? "" : "es") << ": "
+ << getPassesString(PassesToRun) << "\n";
+ EmitProgressBytecode("passinput");
- bool Result = debugPassMiscompilation(ThePass, Output);
+ // 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);
- if (CreatedOutput) removeFile(Output);
- return Result;
-}
+ // Do the reduction...
+ ReduceMiscompilingFunctions(*this).reduceList(MiscompiledFunctions);
-/// debugPassMiscompilation - This method is called when the specified pass
-/// miscompiles Program as input. It tries to reduce the testcase to something
-/// that smaller that still miscompiles the program. ReferenceOutput contains
-/// the filename of the file containing the output we are to match.
-///
-bool BugDriver::debugPassMiscompilation(const PassInfo *Pass,
- const std::string &ReferenceOutput) {
- EmitProgressBytecode(Pass, "passinput");
-
- // Loop over all of the functions in the program, attempting to find one that
- // is being miscompiled. We do this by extracting the function into a module,
- // running the "bad" optimization on that module, then linking it back into
- // the program. If the program fails the diff, the function got misoptimized.
- //
+ std::cout << "\n*** The following function"
+ << (MiscompiledFunctions.size() == 1 ? " is" : "s are")
+ << " being miscompiled: ";
+ PrintFunctionList(MiscompiledFunctions);
+ std::cout << "\n";
+ // Output a bunch of bytecode files for the user...
+ ReduceMiscompilingFunctions(*this).TestFuncs(MiscompiledFunctions, true);
return false;
}
+
projects / oota-llvm.git / blobdiff