Show HN: Online C/C++ to assembly visualizer [Weekend Project]

munin 13 years ago |

LLVM has a similar page: http://llvm.org/demo

you can compile C/C++ to LLVM IR and also 32 or 64 bit intel assembler. you can also see the effects of different optimizations, etc

berkut 13 years ago |

Side by side would be a better layout like: http://gcc.godbolt.org/

option_greek 13 years ago |

Nice project. Will be more useful if there is an explanation of code generated. For example, making the various assembly instructions clickable and displaying information about them. Also a tiny bit of explanation about code and data sections might be of help too :)

ynh 13 years ago | |

Ok added to the todo list

wutwot 13 years ago | | |

You don't filter out CPP macro's. I would skip that and only allow C code. Or run this thing in a proper jail because at the moment:

- doing an include #include "/dev/random" will block the thread. - including "/etc/passwd" is also possible although I don't see a direct way to turn this into password disclosure.

Seriously; even if it's a weekend project, letting people run all kinds of potentially bad code on your machine is never a good idea. Even though you don't run the binaries yourself there's so many ways to mess around with a compiler. You just don't know what's going to happen.

__alexs 13 years ago | | |

chroot would probably be sufficient. Barring some sort of code execution vuln in the compiler you can only load stuff off of the filesystem.

Having the actual CPP available is nice because some bits of libc are only macros.

ynh 13 years ago | | |

I have now added some basic macro detection

yonilevy 13 years ago | | |

#define x "/etc/passwd" #include x

ynh 13 years ago | | |

I have now fixed it. But I think there must be an other way to make it safe. Maybe a sandbox

Ubiquite 13 years ago | |

I could have made the same comment. Good project, could be useful to me. A peace of asm documentation would be tasty.

winter_blue 13 years ago |

This could be a great educational tool! It could be used to teach Introductory Computer Organization at the college level.

I have a suggestion:

- Would you be able to separate the web interface, so that it could used to display Java -> JVM assembly, or any other language. Basically, so that it would be re-usable.

- Putting this up on GitHub would be great.

Finally, great work for just a weekend!

ynh 13 years ago | |

The code is available on github https://github.com/ynh/cpp-to-assembly

unix-dude 13 years ago |

Definitely interesting! Lots of us unix people would just run objdump -d for a quick ASM extraction, but this is probably much friendlier to the user just starting to learn C/ASM.

Overall, Good Job!

jrajav 13 years ago |

Silently fails if you make a syntax error. I accidentally pasted this without newlines and at first I thought it wasn't responding:

  #include <stdio.h>int main() { printf("Hello World"); }

mappu 13 years ago |

Can i recommend adding -masm=intel to your gcc flags? I know AT&T syntax is the default for gcc and gas, but not why. Intel syntax seems clearer to read and is used by most assembly tutorials.

ynh 13 years ago | |

OK I will let the user choose between both syntax

vvnraman 13 years ago |

This really removes any hurdle I might have of inspecting the assembly code due to sheer laziness of opening up my Visual Studio and start debugging. Awesome work. If you add some type of interactivity to the generated assembly, it can be made more visual.

b3b0p 13 years ago |

I love it!

My only suggestion right now is to have it so you can have the assembly on the left or right side. Maybe it's just me, but my focus seems to be on the left side more than the right.

Since this is a focused on assembly it seems, wouldn't you want the focus on the assembly, not the C? It could be different for different people though.

Aardwolf 13 years ago |

In the hello world example, no matter what text you put there, the assembly is the same. Where does the string content go?

berkut 13 years ago | |

Static data in the binary.

tisme 13 years ago |

Very neat! Suggestion: add a 'flags' field where you can specify stuff like -std=c99 and any other flags you might need for your code to compile, and a horizontal rule or something like that after every line of input code.

If you do the 'flags' thing make sure you filter it to avoid escapes to the underlying shell.

gtklocker 13 years ago |

Error: Command failed: /tmp/test969394043.c:1:0: fatal error: can’t open /root/assembler/ccMEBJ3B.s for writing: Permission denied compilation terminated. The bug is not reproducible, so it is likely a hardware or OS problem.

Really.

ynh 13 years ago | |

Just fixed

daurnimator 13 years ago |

Error: Command failed: /bin/sh: 1: c-preload/compiler-wrapper: Permission denied

xymostech 13 years ago | |

I'm getting this too.

ynh 13 years ago | | |

Fixed

ajhai 13 years ago |

Interesting project. As an improvement to the UI, you can consider adding syntax highlighting to the editor. Take a look at ACE editor (http://ace.ajax.org/).

alpb 13 years ago |

Try this on iPad. Generated assembly looks very bad in terms of layout.

Zenst 13 years ago | |

Apple safari browser? Is it also the case with opera or Chrome on the iPad?

jurre 13 years ago | | |

I would guess it will be the same, Chrome on iPad is basically just an iOS webkit wrapper

icefox 13 years ago | |

And you can't load any of the examples

erichocean 13 years ago |

It'd be nice to make, e.g. the for loop clickable, so that it "stuck" and you could scroll down and see where it ended.

As it is now, as soon as you move your mouse, it unhighlights.

akavi 13 years ago |

Does anyone have a link to a good beginner's guide explaining the output?

bostko 13 years ago |

Can't you add a function for memorizing the code written?

Thank you!

ynh 13 years ago | |

Yes I could add some thing like a permanent link creator.

jheriko 13 years ago |

don't work really - some guidance on use might be acceptable. does it need to be a whole program? my snippets give confusing errors about variable identifiers not being types o_0

ynh 13 years ago | |

It must be a valid c/c++ program. Just wrap your code in a function

pgbovine 13 years ago |

excellent -- my unsolicited advice is for you to ping some professors and TAs who teach low-level programming to get them interested in using this in their teaching.