Is there any C function that returns constant variable name for a given input value?

Question

For example lets say I defined a constant as below using #define macro in C

#define MAXSIZE 10

Is there any function in C that I can invoke by passing 10 as input and retrieve that constant name "MAXSIZE". Thanks

It would not be possible to write a function to do this as `#define` is a preprocessor directive, meaning that by the time we get to runtime, it is gone — Ben Wainwright, Mar 15 '17 at 20:36
Is the the question just out of curiosity? If not, describe the actual problem you try to solve so we can give good advice. — Hans, Mar 15 '17 at 20:39

score 5 · Answer 1 · answered Mar 15 '17 at 20:35

5

No for many reasons:

but the actual reason that kills it is:

preprocessor actually replaces MAXSIZE by 10 before compiling, so this information is lost

answered Mar 15 '17 at 20:35

C has no built-in facility for this, but you can write your own function to do as the OP asks, subject to some non-trivial limitations (among them that such a function can support at most one macro name for any given value). – John Bollinger Mar 15 '17 at 20:48

score 2 · Answer 2 · edited Mar 15 '17 at 20:44

2

The answer is no, the c preprocessor replaces all occurences of MAXSIZE with 10 when run.

edited Mar 15 '17 at 20:44

answered Mar 15 '17 at 20:35

KevinDTimm

The answer is C has no *built-in* facility for it, but you can roll your own, subject to some non-trivial limitations. – John Bollinger Mar 15 '17 at 20:45

2 Answers2