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https://github.com/c64scene-ar/llvm-6502.git
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@10839 91177308-0d34-0410-b5e6-96231b3b80d8
322 lines
12 KiB
C++
322 lines
12 KiB
C++
//===- Miscompilation.cpp - Debug program miscompilations -----------------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file was developed by the LLVM research group and is distributed under
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// the University of Illinois Open Source License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file implements program miscompilation debugging support.
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//
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//===----------------------------------------------------------------------===//
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#include "BugDriver.h"
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#include "ListReducer.h"
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#include "llvm/Module.h"
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#include "llvm/Pass.h"
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#include "llvm/Transforms/Utils/Cloning.h"
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#include "llvm/Transforms/Utils/Linker.h"
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#include "Support/FileUtilities.h"
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using namespace llvm;
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namespace llvm {
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class ReduceMiscompilingPasses : public ListReducer<const PassInfo*> {
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BugDriver &BD;
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public:
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ReduceMiscompilingPasses(BugDriver &bd) : BD(bd) {}
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virtual TestResult doTest(std::vector<const PassInfo*> &Prefix,
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std::vector<const PassInfo*> &Suffix);
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};
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}
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ReduceMiscompilingPasses::TestResult
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ReduceMiscompilingPasses::doTest(std::vector<const PassInfo*> &Prefix,
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std::vector<const PassInfo*> &Suffix) {
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// First, run the program with just the Suffix passes. If it is still broken
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// with JUST the kept passes, discard the prefix passes.
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std::cout << "Checking to see if '" << getPassesString(Suffix)
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<< "' compile correctly: ";
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std::string BytecodeResult;
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if (BD.runPasses(Suffix, BytecodeResult, false/*delete*/, true/*quiet*/)) {
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std::cerr << " Error running this sequence of passes"
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<< " on the input program!\n";
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BD.setPassesToRun(Suffix);
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BD.EmitProgressBytecode("pass-error", false);
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exit(BD.debugCrash());
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}
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// Check to see if the finished program matches the reference output...
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if (BD.diffProgram(BytecodeResult, "", true /*delete bytecode*/)) {
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std::cout << "nope.\n";
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return KeepSuffix; // Miscompilation detected!
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}
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std::cout << "yup.\n"; // No miscompilation!
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if (Prefix.empty()) return NoFailure;
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// Next, see if the program is broken if we run the "prefix" passes first,
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// then separately run the "kept" passes.
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std::cout << "Checking to see if '" << getPassesString(Prefix)
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<< "' compile correctly: ";
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// If it is not broken with the kept passes, it's possible that the prefix
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// passes must be run before the kept passes to break it. If the program
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// WORKS after the prefix passes, but then fails if running the prefix AND
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// kept passes, we can update our bytecode file to include the result of the
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// prefix passes, then discard the prefix passes.
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//
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if (BD.runPasses(Prefix, BytecodeResult, false/*delete*/, true/*quiet*/)) {
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std::cerr << " Error running this sequence of passes"
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<< " on the input program!\n";
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BD.setPassesToRun(Prefix);
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BD.EmitProgressBytecode("pass-error", false);
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exit(BD.debugCrash());
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}
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// If the prefix maintains the predicate by itself, only keep the prefix!
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if (BD.diffProgram(BytecodeResult)) {
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std::cout << "nope.\n";
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removeFile(BytecodeResult);
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return KeepPrefix;
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}
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std::cout << "yup.\n"; // No miscompilation!
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// Ok, so now we know that the prefix passes work, try running the suffix
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// passes on the result of the prefix passes.
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//
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Module *PrefixOutput = BD.ParseInputFile(BytecodeResult);
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if (PrefixOutput == 0) {
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std::cerr << BD.getToolName() << ": Error reading bytecode file '"
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<< BytecodeResult << "'!\n";
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exit(1);
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}
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removeFile(BytecodeResult); // No longer need the file on disk
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std::cout << "Checking to see if '" << getPassesString(Suffix)
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<< "' passes compile correctly after the '"
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<< getPassesString(Prefix) << "' passes: ";
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Module *OriginalInput = BD.Program;
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BD.Program = PrefixOutput;
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if (BD.runPasses(Suffix, BytecodeResult, false/*delete*/, true/*quiet*/)) {
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std::cerr << " Error running this sequence of passes"
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<< " on the input program!\n";
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BD.setPassesToRun(Suffix);
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BD.EmitProgressBytecode("pass-error", false);
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exit(BD.debugCrash());
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}
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// Run the result...
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if (BD.diffProgram(BytecodeResult, "", true/*delete bytecode*/)) {
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std::cout << "nope.\n";
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delete OriginalInput; // We pruned down the original input...
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return KeepSuffix;
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}
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// Otherwise, we must not be running the bad pass anymore.
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std::cout << "yup.\n"; // No miscompilation!
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BD.Program = OriginalInput; // Restore original program
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delete PrefixOutput; // Free experiment
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return NoFailure;
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}
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namespace llvm {
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class ReduceMiscompilingFunctions : public ListReducer<Function*> {
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BugDriver &BD;
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public:
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ReduceMiscompilingFunctions(BugDriver &bd) : BD(bd) {}
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virtual TestResult doTest(std::vector<Function*> &Prefix,
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std::vector<Function*> &Suffix) {
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if (!Suffix.empty() && TestFuncs(Suffix, false))
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return KeepSuffix;
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if (!Prefix.empty() && TestFuncs(Prefix, false))
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return KeepPrefix;
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return NoFailure;
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}
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bool TestFuncs(const std::vector<Function*> &Prefix, bool EmitBytecode);
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};
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}
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bool ReduceMiscompilingFunctions::TestFuncs(const std::vector<Function*> &Funcs,
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bool EmitBytecode) {
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// Test to see if the function is misoptimized if we ONLY run it on the
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// functions listed in Funcs.
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if (!EmitBytecode) {
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std::cout << "Checking to see if the program is misoptimized when "
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<< (Funcs.size()==1 ? "this function is" : "these functions are")
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<< " run through the pass"
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<< (BD.PassesToRun.size() == 1 ? "" : "es") << ": ";
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BD.PrintFunctionList(Funcs);
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std::cout << "\n";
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} else {
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std::cout <<"Outputting reduced bytecode files which expose the problem:\n";
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}
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// First step: clone the module for the two halves of the program we want.
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Module *ToOptimize = CloneModule(BD.Program);
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// Second step: Make sure functions & globals are all external so that linkage
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// between the two modules will work.
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for (Module::iterator I = ToOptimize->begin(), E = ToOptimize->end();I!=E;++I)
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I->setLinkage(GlobalValue::ExternalLinkage);
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for (Module::giterator I = ToOptimize->gbegin(), E = ToOptimize->gend();
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I != E; ++I)
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I->setLinkage(GlobalValue::ExternalLinkage);
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// Third step: make a clone of the externalized program for the non-optimized
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// part.
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Module *ToNotOptimize = CloneModule(ToOptimize);
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// Fourth step: Remove the test functions from the ToNotOptimize module, and
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// all of the global variables.
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for (unsigned i = 0, e = Funcs.size(); i != e; ++i) {
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Function *TNOF = ToNotOptimize->getFunction(Funcs[i]->getName(),
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Funcs[i]->getFunctionType());
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assert(TNOF && "Function doesn't exist in module!");
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DeleteFunctionBody(TNOF); // Function is now external in this module!
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}
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for (Module::giterator I = ToNotOptimize->gbegin(), E = ToNotOptimize->gend();
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I != E; ++I)
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I->setInitializer(0); // Delete the initializer to make it external
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if (EmitBytecode) {
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std::cout << " Non-optimized portion: ";
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std::swap(BD.Program, ToNotOptimize);
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BD.EmitProgressBytecode("tonotoptimize", true);
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std::swap(BD.Program, ToNotOptimize);
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}
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// Fifth step: Remove all functions from the ToOptimize module EXCEPT for the
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// ones specified in Funcs. We know which ones these are because they are
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// non-external in ToOptimize, but external in ToNotOptimize.
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//
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for (Module::iterator I = ToOptimize->begin(), E = ToOptimize->end();I!=E;++I)
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if (!I->isExternal()) {
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Function *TNOF = ToNotOptimize->getFunction(I->getName(),
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I->getFunctionType());
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assert(TNOF && "Function doesn't exist in ToNotOptimize module??");
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if (!TNOF->isExternal())
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DeleteFunctionBody(I);
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}
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if (EmitBytecode) {
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std::cout << " Portion that is input to optimizer: ";
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std::swap(BD.Program, ToOptimize);
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BD.EmitProgressBytecode("tooptimize");
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std::swap(BD.Program, ToOptimize);
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}
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// Sixth step: Run the optimization passes on ToOptimize, producing a
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// transformed version of the functions being tested.
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Module *OldProgram = BD.Program;
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BD.Program = ToOptimize;
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if (!EmitBytecode)
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std::cout << " Optimizing functions being tested: ";
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std::string BytecodeResult;
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if (BD.runPasses(BD.PassesToRun, BytecodeResult, false/*delete*/,
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true/*quiet*/)) {
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std::cerr << " Error running this sequence of passes"
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<< " on the input program!\n";
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BD.EmitProgressBytecode("pass-error", false);
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exit(BD.debugCrash());
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}
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if (!EmitBytecode)
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std::cout << "done.\n";
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delete BD.Program; // Delete the old "ToOptimize" module
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BD.Program = BD.ParseInputFile(BytecodeResult);
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if (EmitBytecode) {
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std::cout << " 'tooptimize' after being optimized: ";
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BD.EmitProgressBytecode("optimized", true);
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}
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if (BD.Program == 0) {
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std::cerr << BD.getToolName() << ": Error reading bytecode file '"
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<< BytecodeResult << "'!\n";
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exit(1);
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}
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removeFile(BytecodeResult); // No longer need the file on disk
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// Seventh step: Link the optimized part of the program back to the
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// unoptimized part of the program.
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//
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if (LinkModules(BD.Program, ToNotOptimize, &BytecodeResult)) {
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std::cerr << BD.getToolName() << ": Error linking modules together:"
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<< BytecodeResult << "\n";
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exit(1);
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}
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delete ToNotOptimize; // We are done with this module...
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if (EmitBytecode) {
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std::cout << " Program as tested: ";
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BD.EmitProgressBytecode("linked", true);
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delete BD.Program;
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BD.Program = OldProgram;
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return false; // We don't need to actually execute the program here.
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}
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std::cout << " Checking to see if the merged program executes correctly: ";
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// Eighth step: Execute the program. If it does not match the expected
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// output, then 'Funcs' are being misoptimized!
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bool Broken = BD.diffProgram();
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delete BD.Program; // Delete the hacked up program
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BD.Program = OldProgram; // Restore the original
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std::cout << (Broken ? " nope.\n" : " yup.\n");
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return Broken;
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}
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/// debugMiscompilation - This method is used when the passes selected are not
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/// crashing, but the generated output is semantically different from the
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/// input.
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///
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bool BugDriver::debugMiscompilation() {
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// Make sure something was miscompiled...
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if (!ReduceMiscompilingPasses(*this).reduceList(PassesToRun)) {
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std::cerr << "*** Optimized program matches reference output! No problem "
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<< "detected...\nbugpoint can't help you with your problem!\n";
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return false;
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}
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std::cout << "\n*** Found miscompiling pass"
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<< (PassesToRun.size() == 1 ? "" : "es") << ": "
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<< getPassesString(PassesToRun) << "\n";
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EmitProgressBytecode("passinput");
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// Okay, now that we have reduced the list of passes which are causing the
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// failure, see if we can pin down which functions are being
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// miscompiled... first build a list of all of the non-external functions in
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// the program.
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std::vector<Function*> MiscompiledFunctions;
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for (Module::iterator I = Program->begin(), E = Program->end(); I != E; ++I)
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if (!I->isExternal())
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MiscompiledFunctions.push_back(I);
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// Do the reduction...
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ReduceMiscompilingFunctions(*this).reduceList(MiscompiledFunctions);
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std::cout << "\n*** The following function"
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<< (MiscompiledFunctions.size() == 1 ? " is" : "s are")
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<< " being miscompiled: ";
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PrintFunctionList(MiscompiledFunctions);
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std::cout << "\n";
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// Output a bunch of bytecode files for the user...
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ReduceMiscompilingFunctions(*this).TestFuncs(MiscompiledFunctions, true);
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return false;
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}
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