30  

The GNU linker (ld) supports a --wrap=functionname parameter. I'll simply quote the documentation from the man page as it includes an example which should do exactly what you need:

GNU链接器(ld)支持--wrap = functionname参数。我只是引用手册页中的文档,因为它包含了一个应该完全符合您需要的示例:

--wrap=symbol Use a wrapper function for symbol. Any undefined reference to symbol will be resolved to "__wrap_symbol". Any undefined reference to "__real_symbol" will be resolved to symbol.

--wrap = symbol对符号使用包装函数。任何未定义的符号引用都将解析为“__wrap_symbol”。对“__real_symbol”的任何未定义引用都将解析为符号。

This can be used to provide a wrapper for a system function. The wrapper function should be called "__wrap_symbol". If it wishes to call the system function, it should call "__real_symbol".

这可以用于为系统功能提供包装器。包装函数应该被称为“__wrap_symbol”。如果希望调用系统函数,则应调用“__real_symbol”。

Here is a trivial example:

这是一个简单的例子:

void *
__wrap_malloc (size_t c)
{
    printf ("malloc called with %zu\n", c);
    return __real_malloc (c);
}

If you link other code with this file using --wrap malloc, then all calls to "malloc" will call the function "__wrap_malloc" instead. The call to "__real_malloc" in "__wrap_malloc" will call the real "malloc" function.

如果使用--wrap malloc将其他代码与此文件链接,则对“malloc”的所有调用都将调用函数“__wrap_malloc”。 “__wrap_malloc”中对“__real_malloc”的调用将调用真正的“malloc”函数。

You may wish to provide a "__real_malloc" function as well, so that links without the --wrap option will succeed. If you do this, you should not put the definition of "__real_malloc" in the same file as "__wrap_malloc"; if you do, the assembler may resolve the call before the linker has a chance to wrap it to "malloc".

您可能还希望提供“__real_malloc”函数,以便不使用--wrap选项的链接将成功。如果这样做,则不应将“__real_malloc”的定义放在与“__wrap_malloc”相同的文件中;如果这样做,汇编器可以在链接器有机会将其包装到“malloc”之前解析调用。

4  

I think the alias attribute might solve your problem:

我认为alias属性可能会解决您的问题:

alias ("target")
    The alias attribute causes the declaration to be emitted as an alias for another symbol, which must be specified. For instance,

              void __f () { /* Do something. */; }
              void f () __attribute__ ((weak, alias ("__f")));


    defines `f' to be a weak alias for `__f'. In C++, the mangled name for the target must be used. It is an error if `__f' is not defined in the same translation unit.

    Not all target machines support this attribute.

http://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html

-1  

What about:

#define malloc my_malloc
#include <my_environment.h>
#undef malloc

int malloc(size_t sz)
{
   return my_malloc(sz);
}

#define malloc my_malloc
// use your malloc here