Debugger Quotes

If you're good at the debugger it means you spent a lot of time debugging. I don't want you to be good at the debugger.

Some people can mess up anything, and computational demonology adds a new and unwelcome meaning to terms like “memory leak” and “debugger.

not enough decisions to make, you can also use the debugger to catch exceptions. Go back and comment out the line where you assign mQuestionTextView one more time. Then select Run → Add Java Exception Breakpoint... to pull up the exception breakpoint dialog. Figure 4.10  Setting

So he’d reach into the drawer for the tape with the FLIT debugger and feed that into the computer. The computer would then be a debugging machine, and he’d send the program back in.

History is how you debug our broken society. Many billions of dollars are spent on history in the engineering world. We don’t think about it that way, though. We call it doing a post-mortem, looking over the log files, maybe running a so-called time-travel debugger to get a reproducible bug. Once we find it, we might want to execute an undo, do a git revert, restore from backup, or return to a previously known-good configuration. Think about what we’re saying: on a micro-scale, knowing the detailed past of the system allows us to figure out what had gone wrong. And being able to partially rewind the past to progress along a different branch (via a git revert) empowers us to fix that wrongness. This doesn’t mean throwing away everything and returning to the caveman era of a blank git repository, as per either the caricatured traditionalist who wants to “turn back the clock” or the anarcho-primitivist who wants to end industrialized civilization. But it does mean rewinding a bit to then move forward along a different path16, because progress has both magnitude and direction.

The Fusion log This is a very useful tool for debugging failed attempts by the CLR to bind to an assembly at run time. Rather than trying to step through the application in the Visual Studio debugger, it is better to turn Fusion on and read the log file that results. To enable Fusion you must edit the Windows registry, as shown in the following code.HKLM\Software\Microsoft\Fusion\ForceLog 1 HKLM\Software\Microsoft\Fusion\LogPath C:\FusionLogs

To initiate the debugger, all you have to do is import the pdb built-in module and run its set_trace function. You’ll often see this done in a single line so programmers can comment it out with a single # character.

debugger, a tool that will preserve your C source code after compilation and enable you to do such things as step through it manually, or alter data as an aid to finding and correcting programming errors.

Names A name is a letter optionally followed by one or more letters, digits, or underbars. A name cannot be one of these reserved words: abstract boolean break byte case catch char class const continue debugger default delete do double else enum export extends false final finally float for function goto if implements import in instanceof int interface long native new null package private protected public return short static super switch synchronized this throw throws transient true try typeof var volatile void while with Most of the reserved words in this list are not used in the language. The list does not include some words that should have been reserved but were not, such as undefined, NaN, and Infinity. It is not permitted to name a variable or parameter with a reserved word. Worse, it is not permitted to use a reserved word as the name of an object property in an object literal or following a dot in a refinement. Names are used for statements, variables, parameters, property names, operators, and labels.

Thompson, who designed and implemented the first UNIX system, has stated that he much prefers printf debugging.24 But as Baird put it, “If you are a genius like Ken Thompson, you are going to write good code.”25 The rest of us need to move beyond printf debugging to get our code working, as I rapidly discovered once I started working on the internals of Windows NT at Microsoft (the fundamental skill is learning to use a specialized piece of software called a debugger, which can examine the memory of another program).

I really believed that computers were deterministic, that you could understand what they were supposed to do, and that there was no excuse for computers not working, for things not functioning properly. In retrospect, I was surprisingly good at keeping the system running, putting in new code and having it not break the system. That was the first instance of something I got an undeserved reputation for. I know that my boss, and probably some other of my colleagues, have said I was a great debugger. And that's partly true. But there's a fake in there. Really what I was was a very careful programmer with the arrogance to believe that very few computer programs are inherently difficult. I would take some piece of code that didn't look like it was working and I would try to read it. And if I could understand, then I could usually see what was wrong or poke around with it and fix it. But sometimes I would get a piece of code—often one that other people couldn't make work—and I would say, “This is way too complicated.” So I would think through what it was supposed to do, throw it away, and write it again from scratch. Some of the folks I worked with—like Will Crowther—who are terrific programmers, couldn't tolerate that. They would believe that by doing that, I would probably have fixed the 2 bugs that were there and introduced 27 new bugs. But the fact is, I was good at that. So I would rewrite stuff completely and it would be organized differently than the original programmer had organized it because I had thought about the problem differently. Typically, it was simpler than it used to be, or at least simpler to my eyes. And it would work. So I got this reputation—I fixed these mysterious bugs that nobody else could fix. Fortunately, they never asked me what the bug was. Because the truth of the matter is if they'd have asked, “How did you fix the bug?” my answer would have been, “I couldn't understand the code well enough to figure out what it was doing, so I rewrote it.” I did that a lot on the PDP-1 time-sharing system. There were chunks of the code that I would read and would say, “This doesn't do what I think this part of the program is supposed to be doing,” or “It's weird.” So I'd rewrite it. The only thing that kept me working there, with that attitude, was that I had a good track record. That's one of the things, that if you're not good at it, you make chaos. But if you are good at it, the world thinks that you can do things that you can't, really.

Most demons are as dumb as a sackful of hammers. This does not mean they’re safe to mess with, any more than a C++ compiler is “safe” in the hands of an enthusiastic computer science undergrad. Some people can mess up anything, and computational demonology adds a new and unwelcome meaning to terms like “memory leak” and “debugger.” Now,

abstract boolean break byte case catch char class const continue debugger default do else enum export extends false final finally float for function goto if implements import in instanceof int interface let long native new null package private protected public return short super switch synchronized this throws transient true try typeof var void volatile while with Comments

I really believed that computers were deterministic, that you could understand what they were supposed to do, and that there was no excuse for computers not working, for things not functioning properly. In retrospect, I was surprisingly good at keeping the system running, putting in new code and having it not break the system. That was the first instance of something I got an undeserved reputation for. I know that my boss, and probably some other of my colleagues, have said I was a great debugger. And that's partly true. But there's a fake in there. Really what I was was a very careful programmer with the arrogance to believe that very few computer programs are inherently difficult. I would take some piece of code that didn't look like it was working and I would try to read it. And if I could understand, then I could usually see what was wrong or poke around with it and fix it. But sometimes I would get a piece of code—often one that other people couldn't make work—and I would say, “This is way too complicated.” So I would think through what it was supposed to do, throw it away, and write it again from scratch. Some of the folks I worked with—like Will Crowther—who are terrific programmers, couldn't tolerate that. They would believe that by doing that, I would probably have fixed the 2 bugs that were there and introduced 27 new bugs. But the fact is, I was good at that. So I would rewrite stuff completely and it would be organized differently than the original programmer had organized it because I had thought about the problem differently. Typically, it was simpler than it used to be, or at least simpler to my eyes. And it would work. So I got this reputation—I fixed these mysterious bugs that nobody else could fix. Fortunately, they never asked me what the bug was. Because the truth of the matter is if they'd have asked, “How did you fix the bug?” my answer would have been, “I couldn't understand the code well enough to figure out what it was doing, so I rewrote it.