Automatic source code replacement

Question

I'm looking for a tool, regex or other magic to do some heavy code replacements.

Ideally I would be able to replace all instances of the new operator with a call to a function preserving the arguments.

What are my options?

Update:

Example:

ClassA* a = new ClassA<int>(1,2,3,4,new ClassB(1,2),"horrible");

Should transform to:

ClassA* a = FUNCTION(ClassA<int>(1,2,3,4,FUNCTION(ClassB(1,2)),"horrible"));

Where FUNCTION will do something like:

FUNCTION(...) Debug(new __VA_ARGS__, __FILE__)

A simple replace nearly does it well, it only lacks the last ).

Update:

My initial thought was to use a macro to track some additional info like __FILE__, store it in a std container and then call new. What will happen if the container calls new? How do I add __FILE__ inside an overloaded new?

could you give us an example of the input and the output? – arutaku Jan 31 '13 at 07:45 — arutaku, Jan 31 '13 at 07:45
Uh, `Ctrl+H` in most IDEs support regex. – Mark Garcia Jan 31 '13 at 07:45 — Mark Garcia, Jan 31 '13 at 07:45
What OS? What code-editor do you use? – psur Jan 31 '13 at 07:50 — psur, Jan 31 '13 at 07:50
Good luck matching parentheses with regexes... – user541686 Jan 31 '13 at 08:11 — user541686, Jan 31 '13 at 08:11

score 2 · Accepted Answer · edited May 23 '17 at 10:31

2

You don't mention why you want to do this, but I do wonder whether overloading the new operator might be a better option for you.

Why would one replace default new and delete operators?

Edit

The following links might also be relevant:

overloading new and delete in c++

Overriding "new" and Logging data about the caller

Macro to replace C++ operator new

http://blogs.msdn.com/b/calvin_hsia/archive/2009/01/19/9341632.aspx

It seems like this is a problem many people have tackled before. Googling for overload|override new __line__ __file__ will throw up further possibilities.

edited May 23 '17 at 10:31

Community

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answered Jan 31 '13 at 08:25

Ian Goldby

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@Inuart You haven't said what the Debug function does, but (with my limited knowledge) I don't see any obvious reason why overloading new wouldn't be feasible. It's not something I've ever done myself though. Study the information in the link carefully to see if it is applicable to your case. – Ian Goldby Jan 31 '13 at 10:17
My initial thought was to use a macro to track some additional info like `__FILE__`, store it in a std container and then call `new`. What will happen if the container calls `new`? How do I add `__FILE__` inside an overloaded `new`? – Inuart Jan 31 '13 at 17:35
Good question. I don't have an answer to that. Anyone? – Ian Goldby Feb 01 '13 at 08:35

score 1 · Answer 2 · answered Jan 31 '13 at 07:52

Some of your more viable options:

If it is only a few files, you could simply go through them in an IDE and use CTRL+H to find and replace (Thank you Mark Garcia)

If it is many files, you could write a Perl script to find and replace regular expression (I suggest Perl only because I have found regular expressions to be very straightforward in it) This could be done in a single line actually

perl -p -i -e 's/oldstring/newstring/g' `find ./ -name *.cpp`

Running this from command line will replace all instances of oldstring with newstring in every .cpp file in the current directory. Honestly, this is probably the most straightforward way for many files if you are simply replacing all instances of 'new' with another single string. Although this situation is unlikely, but you can always change old string to be whatever you want (say 'new Object' replaced with createObject)

how I add the final `)` with a regular expression? – Inuart Jan 31 '13 at 08:10 — Inuart, Jan 31 '13 at 08:10

Automatic source code replacement

2 Answers2