problems in C functions call C++

[Mike Stump]

On Friday, September 16, 2005, at 10:01  AM, Tian Dale-A19565 wrote:
> Functions (mentioned above, implemented in C++, called by C) were 
> unresolved, that means the linker cannot locate the implementation of 
> those functions.
>
> Could you help me to solve this problem?

The ability to answer is dependent upon the quality of the question.  
If you case you removed all details that allow anyone from helping you.

Compare your question to:

When I compile:

extern "C" void foo() {
}

I get:

.public foo
foo:
	ret

at -O2 using gcc 3.4.3 on arm-elf and when I assemble this with 
binutils 2.904, nm shows no foo in the symbol table, is the compiler 
broken?

Here we see the input to the compiler, the output from the compiler, 
the compilation flags used and so on...  That has an answer, and it is 
no; further, we could say that as from binutils appears to be broken, 
and then have you go ask the binutils people about it.

So, cut down the testcase to a small example, show us the full source 
code (gcc -E), the flags used to compile, the .s file produced and the 
name of the symbol in question...