llvm-6502/tools/bugpoint/CrashDebugger.cpp

121 lines
3.9 KiB
C++
Raw Normal View History

//===- CrashDebugger.cpp - Debug compilation crashes ----------------------===//
//
// This file defines the bugpoint internals that narrow down compilation crashes
//
//===----------------------------------------------------------------------===//
#include "BugDriver.h"
#include "llvm/Module.h"
#include "llvm/Bytecode/Writer.h"
#include "llvm/Pass.h"
#include <fstream>
/// debugCrash - This method is called when some pass crashes on input. It
/// attempts to prune down the testcase to something reasonable, and figure
/// out exactly which pass is crashing.
///
bool BugDriver::debugCrash() {
std::cout << "\n*** Debugging optimizer crash!\n";
// Determine which pass causes the optimizer to crash... using binary search
unsigned LastToPass = 0, LastToCrash = PassesToRun.size();
while (LastToPass != LastToCrash) {
unsigned Mid = (LastToCrash+LastToPass+1) / 2;
std::vector<const PassInfo*> P(PassesToRun.begin(),
PassesToRun.begin()+Mid);
std::cout << "Checking to see if the first " << Mid << " passes crash: ";
if (runPasses(P))
LastToCrash = Mid-1;
else
LastToPass = Mid;
}
// Make sure something crashed. :)
if (LastToCrash >= PassesToRun.size()) {
std::cerr << "ERROR: No passes crashed!\n";
return true;
}
// Calculate which pass it is that crashes...
const PassInfo *CrashingPass = PassesToRun[LastToCrash];
std::cout << "\n*** Found crashing pass '-" << CrashingPass->getPassArgument()
<< "': " << CrashingPass->getPassName() << "\n";
// Compile the program with just the passes that don't crash.
if (LastToPass != 0) {
// Don't bother doing this if the first pass crashes...
std::vector<const PassInfo*> P(PassesToRun.begin(),
PassesToRun.begin()+LastToPass);
std::string Filename;
std::cout << "Running passes that don't crash to get input for pass: ";
if (runPasses(P, Filename)) {
std::cerr << "ERROR: Running the first " << LastToPass
<< " passes crashed this time!\n";
return true;
}
// 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);
}
return debugPassCrash(CrashingPass);
}
/// CountFunctions - return the number of non-external functions defined in the
/// module.
static unsigned CountFunctions(Module *M) {
unsigned N = 0;
for (Module::iterator I = M->begin(), E = M->end(); I != E; ++I)
if (!I->isExternal())
++N;
return N;
}
/// debugPassCrash - This method is called when the specified pass crashes on
/// Program as input. It tries to reduce the testcase to something that still
/// crashes, but it smaller.
///
bool BugDriver::debugPassCrash(const PassInfo *Pass) {
EmitProgressBytecode(Pass, "passinput");
if (CountFunctions(Program) > 1) {
// Attempt to reduce the input program down to a single function that still
// crashes.
//
std::cout << "\n*** Attempting to reduce the testcase to one function\n";
for (Module::iterator I = Program->begin(), E = Program->end(); I != E; ++I)
if (!I->isExternal()) {
// Extract one function from the module...
Module *M = extractFunctionFromModule(I);
// Make the function the current program...
std::swap(Program, M);
// Find out if the pass still crashes on this pass...
std::cout << "Checking function '" << I->getName() << "': ";
if (runPass(Pass)) {
// Yup, it does, we delete the old module, and continue trying to
// reduce the testcase...
delete M;
EmitProgressBytecode(Pass, "reduced-"+I->getName());
break;
}
// This pass didn't crash on this function, try the next one.
delete Program;
Program = M;
}
}
return false;
}