Re: question about some terms

[loody <miloody at gmail dot com>]

Hi:
2009/5/13 Cary Coutant <ccoutant@google.com>:
>> There are some terms I cannot figure them out clearly.
>
> There's a bit of fuzziness in these terms, but in general, you're pretty close.
>
>> 1. relocatable file:
>> ? ?(are they *.a and *.o files)
>
> More accurately, .a files are archive (or static) libraries, whose
> members are relocatable objects (.o files).
>
>> 2. executable file
>> ? ?(are they *.out files)
>
> These are the output of a normal link (i.e., no -r option and no
> -shared option). The ".out" extension is a bit ambiguous, as "a.out"
> is both the traditional default output file name used by the Unix
> assembler (usually a relocatable object, but traditionally the
> assembler could also produce an executable file), and the default
> output file name used by the linker. Normally an executable file has
> been linked, has an entry point, and may or may not have dependencies
> on shared objects (shared libraries).
>
>> 3. shared object file
>> ? ?(are they *.so files)
>
> Yes. Also called shared libraries or dynamic-link libraries (DLLs).
>
>> 4. Dynamically loaded libraries
>> ? ?(what is the difference between 3 and 4)
>
> In general, a dynamically-loaded library is a shared library that is
> loaded during program execution via dlopen() (or equivalent), as
> opposed to one that is listed as a dependency (directly or indirectly)
> on the executable.
>
> -cary
thanks for your kind help.
BTW, while reading ld and compare it with some sd scripts.
I saw some sections that I have no idea what it mean.
1. .sbss
2. .scommon
3. .sdata
4. .gptab
5. .lib8
6. .lit4
7. .reginfo
Those are not symbol that will be used under program.
it seems the default sections that will be generated by compiler.
Does there any document provide the whole list and purpose of them?
appreciate your kind help,
miloody