llvm-6502/lib/Support/SlowOperationInformer.cpp

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//===-- SlowOperationInformer.cpp - Keep the user informed ----------------===//
//
// 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 the SlowOperationInformer class for the LLVM debugger.
//
//===----------------------------------------------------------------------===//
#include "llvm/Support/SlowOperationInformer.h"
#include "llvm/Config/config.h" // Get the signal handler return type
#include <iostream>
#include <sstream>
#include <signal.h>
#include <unistd.h>
#include <cassert>
using namespace llvm;
/// OperationCancelled - This flag is set by the SIGINT signal handler if the
/// user presses CTRL-C.
static volatile bool OperationCancelled;
/// ShouldShowStatus - This flag gets set if the operation takes a long time.
///
static volatile bool ShouldShowStatus;
/// NestedSOI - Sanity check. SlowOperationInformers cannot be nested or run in
/// parallel. This ensures that they never do.
static bool NestedSOI = false;
static RETSIGTYPE SigIntHandler(int Sig) {
OperationCancelled = true;
signal(SIGINT, SigIntHandler);
}
static RETSIGTYPE SigAlarmHandler(int Sig) {
ShouldShowStatus = true;
}
static void (*OldSigIntHandler) (int);
SlowOperationInformer::SlowOperationInformer(const std::string &Name)
: OperationName(Name), LastPrintAmount(0) {
assert(!NestedSOI && "SlowerOperationInformer objects cannot be nested!");
NestedSOI = true;
OperationCancelled = 0;
ShouldShowStatus = 0;
signal(SIGALRM, SigAlarmHandler);
OldSigIntHandler = signal(SIGINT, SigIntHandler);
alarm(1);
}
SlowOperationInformer::~SlowOperationInformer() {
NestedSOI = false;
if (LastPrintAmount) {
// If we have printed something, make _sure_ we print the 100% amount, and
// also print a newline.
std::cout << std::string(LastPrintAmount, '\b') << "Progress "
<< OperationName << ": 100% \n";
}
alarm(0);
signal(SIGALRM, SIG_DFL);
signal(SIGINT, OldSigIntHandler);
}
/// progress - Clients should periodically call this method when they are in
/// an exception-safe state. The Amount variable should indicate how far
/// along the operation is, given in 1/10ths of a percent (in other words,
/// Amount should range from 0 to 1000).
void SlowOperationInformer::progress(unsigned Amount) {
if (OperationCancelled) {
std::cout << "\n";
LastPrintAmount = 0;
throw "While " + OperationName + ", operation cancelled.";
}
// If we haven't spent enough time in this operation to warrant displaying the
// progress bar, don't do so yet.
if (!ShouldShowStatus)
return;
// Delete whatever we printed last time.
std::string ToPrint = std::string(LastPrintAmount, '\b');
std::ostringstream OS;
OS << "Progress " << OperationName << ": " << Amount/10;
if (unsigned Rem = Amount % 10)
OS << "." << Rem << "%";
else
OS << "% ";
LastPrintAmount = OS.str().size();
std::cout << ToPrint+OS.str() << std::flush;
}