gcc -fpic 参数解释

gcc -fpic

创建共享库和链接可执行文件类似：首先把源代码编译成目标文件， 然后把目标文件链接起来。目标文件需要创建成位置无关码（position-independent code） （PIC），概念上就是在可执行程序装载它们的时候， 它们可以放在可执行程序的内存里的任何地方， （用于可执行文件的目标文件通常不是用这个方式编译的。） 链接动态库的命令包含特殊标志，与链接可执行文件的命令是有区别的。

http://topic.csdn.net/t/20041026/16/3493005.html

man gcc

-fpic
Generate position-independent code (PIC) suitable for use in a
shared library, if supported for the target machine. Such code
accesses all constant addresses through a global offset table
(GOT). The dynamic loader resolves the GOT entries when the pro-
gram starts (the dynamic loader is not part of GCC; it is part of
the operating system). If the GOT size for the linked executable
exceeds a machine-specific maximum size, you get an error message
from the linker indicating that -fpic does not work; in that case,
recompile with -fPIC instead. (These maximums are 8k on the SPARC
and 32k on the m68k and RS/6000. The 386 has no such limit.)

Position-independent code requires special support, and therefore
works only on certain machines. For the 386, GCC supports PIC for
System V but not for the Sun 386i. Code generated for the IBM
RS/6000 is always position-independent.

-fPIC
If supported for the target machine, emit position-independent
code, suitable for dynamic linking and avoiding any limit on the
size of the global offset table. This option makes a difference on
the m68k and the SPARC.

Position-independent code requires special support, and therefore
works only on certain machines.