Any program or trick to find the definition of a variable?

Question

Many times when I am watching others code I just want to find where and how a variable is defined. Normally what I do now is look for the type of the variable until I find t

Answer 1

I use one of three methods:

1. I will use CTags to process my source tree (nightly) and then can easily use commands in Vim (or other editors) to jump right to the definition.
2. I will just use grep (linux) or findstr (windows) to look for all occurrences of the variable name or type. The definition is usually quite obvious.
3. In Vim, you can just search backward in the scope and often find what you are looking for.

Answer 2

In VIM you can use gd to see local variable declarations or gD to see global variable declarations, if they're defined in the current file. Reference Go_to_definition_using_g

You can also use [i to see the definition without jumping to it, or [I to see all occurrences of the variable in all the included files as well, which will naturally show the definition as well.

Answer 3

I use cscope and ctags-exuberant religiously. Run it once on my code base and then in Vim, I can use various commands like ^] or [D or [I or similar to find any definitions or declarations for a given word.

This is similar to facilities provided by mega-IDEs like Visual Studio and Eclipse.

Cscope also functions as a stand-alone tool that performs these searches.

Answer 4

Grep for common patterns for variable declarations. Example: *, &, > or an alphanumeric followed by one or more whitespace characters then the name of the variable. Or variable name followed by zero or more whitespace characters, then a left parenthesis or a semicolon. Unless it was defined under really weird circumstances (like with some kind of macro), it works every time.

Answer 5

You've already given the most appropriate tool: an IDE. This is exactly the kind of thing which an IDE excels at. Why would you not want to use an IDE if you're finding development painful without one?

Note that Emacs, Vim etc can work as IDEs - I'm not talking about forcing you the world of GUIs if you want to stay in a text-only situation, e.g. because you're SSHing in.

(I'm really not trying to be rude here. I just think you've discounted the obvious solution without explaining why.)

Answer 6

if you insist on staying text mode, you can do this with either emacs or vi with the appropriate plug-ins.

But really, move into the 21st century.

EDIT: You commented that you are doing this over SSH because you need the build speed of the remote server cluster.

In that case, mount the drive on your local machine and use an IDE, and just SSH in to kick off a build.