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Here's a problem I've had recently that just HAS to be a common pain to others here.
I'm working with someone else's legacy C code and need to find where a function or macro was defined. The code #includes a bunch of different standard system libraries in addition to those from the specific project.
Is there a tool or technique to quickly find where a specific function, macro, (or other global for that matter) was defined?
I tried:
grep -R 'function' /usr/lib
and other similar *nix/bash-fu with only limited success and lots of annoying chaff to cull. One of you sage coders out there must have a good solution to this seemingly common scenario.
I was very surprised to not find another question on this particular pain here or in my searches of the interwebs. (I'm sure there will be angry comments if I missed one... ;-))
Thanks in advance for any tips!
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You make the declarations in a header file, then use the #include directive in every . cpp file or other header file that requires that declaration. The #include directive inserts a copy of the header file directly into the . cpp file prior to compilation.
<bits/stdc++. h> in C++ It is basically a header file that includes every standard library.
To check if an header file has been included or not in a C or C++ code, we need to check if the macro defined in the header file is being defined in the client code. Standard header files like math. h have their own unique macro (like _MATH_H ) which we need to check. Consider this example of checking if math.
The Hash symbol directs the compiler to load the header file in the program.
Use etags/ctags from the exuberant ctags project in conjunction with an editor (emacs, vim) that understands them, or GNU GLOBAL.
Oh, and if you happen to use automake it generates a target TAGS. So no need for complicated manual calls to {c,e}tags.
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