ARM library and function names are visible!

[ebuddy]

Hi,

I coded an algorithm function (in C code) in RVDS 4.0 environment for a customer. The targeted device is ARM926EJ-S. I compiled it into a library and give the ".a" file and ".h" files to the customer. My customer can call the function in their main program.

The thing is my customer can see what is in my ".a" file. I mean they can see all the function names in my algorithm! Every function I used in the algorithm is listed under ".axf" file. I just don't like it. The library I delivered to the customer should be binary code and not readable.

Any one has experience on this?

Thanks.

 

[alexan_e]

The purpose of the header file is to declare all the functions names of the library so they can be used in the code so how do you expect the names to be hidden?

Alex

 

[ebuddy]

Thanks Alex. Your posted helped me to realize the problem I have, but I have not got the answer by myself. Hope you can help. Let me first clarify my problem:

I have my code structured in such a way:

in library source abc.c file:
---------------------------------
void s1 (...) { ... }
void s2 (...) { ... }
void s3 (...) { ... }
void abc (... ) {
s1 (...);
s2 (...);
s3 (...);
}
---------------------------------

in header abc.h file
---------------------------------
void abc (... ) ;
---------------------------------

I compiled abc.c to abc.a file, and give it, together with abc.h, to the customer.

The customer can see that I have function abc,s1,s2,s3 in my library, which is not good. All I want customer to see is function abc. I don't want them to know that I implemented my abc function using s1,s2,s3. S1,s2,s3 are only used in abc function. I need to make them "private" to abc function.

Any suggestion how I can do it? Thanks.

 

[alexan_e]

I think you need to use static functions
**broken link removed**
Static Functions in C ~ codingfreak

Alex

 

[ebuddy]

Thanks Alex. You got the solution for me.

What should I do if I want to keep the variables defined in abc.c local to abc.c file? Can I do it the same way as I do to functions? for example,

in library source abc.c file:
---------------------------------
static unsigned char k1[] = {0,1,2};

static void s1 (...) { ... }
static void s2 (...) { ... }
static void s3 (...) { ... }

void abc (... ) {
s1 (...);
s2 (...);
s3 (...);
}
------------------------------------

Is this is the correct way to keep k1 visible only to abc.c file? Thanks.

 

[alexan_e]

Yes the static variable is the solution

Static global variables: variables declared as static at the top level of a source file (outside any function definitions) are only visible throughout that file ("file scope", also known as "internal linkage").

Static variable - Wikipedia, the free encyclopedia

Alex