#include <stdio.h>

int main(int argc, char *argv[]) {
  printf("Hello, World!\n");
  return 0;
}

~]$ scl enable devtoolset-2 'gcc -o hello hello.c'

~]$ ./hello
Hello, World!

#include <iostream>

using namespace std;

int main(int argc, char *argv[]) {
  cout << "Hello, World!" << endl;
  return 0;
}

~]$ scl enable devtoolset-2 'g++ -o hello hello.cpp'

~]$ ./hello
Hello, World!

      program hello
        print *, "Hello, World!"
      end program hello

~]$ scl enable devtoolset-2 'gfortran -o hello hello.f'

~]$ ./hello
 Hello, World!

~]$ scl enable devtoolset-2 'git config --global core.editor vim'

~]$ scl enable devtoolset-2 'git config --global user.name "John Doe"'
~]$ scl enable devtoolset-2 'git config --global user.email "john@example.com"'

~]$ scl enable devtoolset-2 'strace -o fibonacci.log ./fibonacci 20'
1 1 2 3 5 8 13 21 34 55 89 144 233 377 610 987 1597 2584 4181 6765

~]$ scl enable devtoolset-2 'strace -e mmap,munmap ./employee'
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f896c744000
mmap(NULL, 61239, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f896c735000
mmap(0x3146a00000, 3745960, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x3146a00000
mmap(0x3146d89000, 20480, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x189000) = 0x3146d89000
mmap(0x3146d8e000, 18600, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x3146d8e000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f896c734000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f896c733000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f896c732000
munmap(0x7f896c735000, 61239)           = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f896c743000
John,john@example.comDoe,
+++ exited with 0 +++

~]$ scl enable devtoolset-2 'strace -tt ./pwd'
19:43:28.011815 execve("./pwd", ["./pwd"], [/* 36 vars */]) = 0
19:43:28.012128 brk(0)                  = 0xcd3000
19:43:28.012174 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fc869cb0000
19:43:28.012427 open("/etc/ld.so.cache", O_RDONLY) = 3
19:43:28.012446 fstat(3, {st_mode=S_IFREG|0644, st_size=61239, ...}) = 0
19:43:28.012464 mmap(NULL, 61239, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7fc869ca1000
19:43:28.012483 close(3)                = 0
...
19:43:28.013410 +++ exited with 0 +++

~]$ scl enable devtoolset-2 'strace -c ./lsblk > /dev/null'
% time     seconds  usecs/call     calls    errors syscall
------ ----------- ----------- --------- --------- ----------------
 80.88    0.000055           1       106        16 open
 19.12    0.000013           0       140           munmap
  0.00    0.000000           0       148           read
  0.00    0.000000           0         1           write
  0.00    0.000000           0       258           close
  0.00    0.000000           0        37         2 stat
...
------ ----------- ----------- --------- --------- ----------------
100.00    0.000068                  1790        35 total

#include <stdio.h>

void print_iteration(int value) {
  printf("Iteration number %d\n", value);
}

int main(int argc, char **argv) {
  int i;
  printf("Enter the starting number: ");
  scanf("%d", &i);
  for(; i>0; --i)
    print_iteration(i);
  return 0;
}

~]$ scl enable devtoolset-2 'g++ -g -o exercise exercise.C'

#!/usr/bin/stap

global count = 0

probe process.function("print_iteration") {
  count++
}

probe end {
  printf("Function executed %d times.\n", count)
}

~]$ scl enable devtoolset-2 "stap --dyninst -c './exercise' count.stp"
Enter the starting number: 5
Iteration number 5
Iteration number 4
Iteration number 3
Iteration number 2
Iteration number 1
Function executed 5 times.

#include <stdio.h>
#include <fcntl.h>
#include "BPatch.h"
#include "BPatch_process.h"
#include "BPatch_function.h"
#include "BPatch_Vector.h"
#include "BPatch_thread.h"
#include "BPatch_point.h"

void usage() {
  fprintf(stderr, "Usage: count <process_id> <function>\n");
}

// Global information for counter
BPatch_variableExpr *counter = NULL;

void createCounter(BPatch_process *app, BPatch_image *appImage) {
  int zero = 0;
  counter = app->malloc(*appImage->findType("int"));
  counter->writeValue(&zero);
}

bool interceptfunc(BPatch_process *app,
                   BPatch_image *appImage,
                   char *funcName) {
  BPatch_Vector<BPatch_function *> func;
  appImage->findFunction(funcName, func);
  if(func.size() == 0) {
    fprintf(stderr, "Unable to find function to instrument()\n");
    exit (-1);
  }
  BPatch_Vector<BPatch_snippet *> incCount;
  BPatch_Vector<BPatch_point *> *points;
  points = func[0]->findPoint(BPatch_entry);
  if ((*points).size() == 0) {
    exit (-1);
  }

  BPatch_arithExpr counterPlusOne(BPatch_plus, *counter, BPatch_constExpr(1));
  BPatch_arithExpr addCounter(BPatch_assign, *counter, counterPlusOne);

  return app->insertSnippet(addCounter, *points);
}


void printCount(BPatch_thread *thread, BPatch_exitType) {
  int val = 0;
  counter->readValue(&val, sizeof(int));
  fprintf(stderr, "Function executed %d times.\n", val);
}

BPatch bpatch;

int main(int argc, char *argv[]) {
  int pid;
  if (argc != 3) {
    usage();
    exit(1);
  }
  pid = atoi(argv[1]);
  BPatch_process *app = bpatch.processAttach(NULL, pid);
  if (!app) exit (-1);
  BPatch_image *appImage = app->getImage();
  createCounter(app, appImage);
  fprintf(stderr, "Finding function %s(): ", argv[2]);
  BPatch_Vector<BPatch_function*> countFuncs;
  fprintf(stderr, "OK\nInstrumenting function %s(): ", argv[2]);
  interceptfunc(app, appImage, argv[2]);
  bpatch.registerExitCallback(printCount);
  fprintf(stderr, "OK\nWaiting for process %d to exit...\n", pid);
  app->continueExecution();
  while (!app->isTerminated())
    bpatch.waitForStatusChange();
  return 0;
}

DTS      = /opt/rh/devtoolset-2/root
CXXFLAGS = -g -I$(DTS)/usr/include/dyninst
LBITS   := $(shell getconf LONG_BIT)

ifeq ($(LBITS),64)
  DYNINSTLIBS = $(DTS)/usr/lib64/dyninst
else
  DYNINSTLIBS = $(DTS)/usr/lib/dyninst
endif

.PHONY: all
all: count exercise

count: count.C
	g++ $(CXXFLAGS) count.C -I /usr/include/dyninst -c
	g++ $(CXXFLAGS) count.o -L $(DYNINSTLIBS) -ldyninstAPI -o count

exercise: exercise.C
	g++ $(CXXFLAGS) exercise.C -o exercise

.PHONY: clean
clean:
	rm -rf *~ *.o count exercise

~]$ scl enable devtoolset-2 make
g++ -g -I/opt/rh/devtoolset-2/root/usr/include/dyninst count.C -c
g++ -g -I/opt/rh/devtoolset-2/root/usr/include/dyninst count.o -L /opt/rh/devtoolset-2/root/usr/lib64/dyninst -ldyninstAPI -o count
g++ -g -I/opt/rh/devtoolset-2/root/usr/include/dyninst exercise.C -o exercise

~]$ ./exercise
Enter the starting number:

~]$ export DYNINSTAPI_RT_LIB=/opt/rh/devtoolset-2/root/usr/lib64/dyninst/libdyninstAPI_RT.so.8.0
~]$ ./count `pidof exercise` print_iteration
Finding function print_iteration(): OK
Instrumenting function print_iteration(): OK
Waiting for process 8607 to exit...

Enter the starting number: 5
Iteration number 5
Iteration number 4
Iteration number 3
Iteration number 2
Iteration number 1

Function executed 5 times.