静态编译（一）

声明：该文章转载自http://blog.csdn.net/mymtom/article/details/1682767，在此多谢该文章创作者 的分享。

FreeBSD 环境下，缺省的链接方式为动态链接，然而有时由于运行环境的限制，需要进行静态链接。

GNU LD的手册上对静态链接的描述很简单：

-Bstatic
-dn
-non_shared
-static
Do  not  link against shared libraries.  This is only meaningful on
platforms for which shared libraries are supported. The  different
variants of this option are for compatibility with various systems.
You may use this option multiple times  on  the  command  line:  it
affects  library  searching for  -l options which follow it.  This
option also implies --unresolved-symbols=report-all.

实践中简单的加上静态链接选项-static并不能解决问题。

动态链接时LD能动态分析调用依赖关系，调整链接顺序，顺利完成链接。

静态链接时，LD以固定顺序进行链接，命令行的目标文件和库之间需要按调顺序出现（即调用的目标文件或库在前，被调用的库在后），才能链接成功，如果顺序不正确，往往链接失败。下面的有一个例子。

Makefile

#
# Makefile
#

CFLAGS += -static -I/usr/local/include
LDFLAGS+= -L/usr/local/lib -liconv

PROG   = gb2u
OBJS   = gb2u.o

all:   $(PROG)

gb2u:  $(OBJS)
       $(CC)$(CFLAGS)$(CPPFLAGS) -o$@ $(OBJS)$(LDFLAGS)$(LOADLIBES)$(LDLIBS)

clean:
        rm -rf$(PROG)$(OBJS)
mymtom@FreeBSD:/usr/home/mymtom/src/locale/gb2u$ cat gb2u.mk
CFLAGS += -static -I/usr/local/include
LDFLAGS+= -L/usr/local/lib -liconv

PROG   = gb2u
OBJS   = gb2u.o

all:   $(PROG)

gb2u:  $(OBJS)
       $(CC)$(CFLAGS)$(CPPFLAGS)$(LDFLAGS)$(OBJS)$(LOADLIBES)$(LDLIBS) -o$@

clean:
        rm -rf$(PROG)$(OBJS)

gb2u.mk

#
# gb2u.mk
#
CFLAGS += -static -I/usr/local/include
LDFLAGS+= -L/usr/local/lib -liconv

PROG   = gb2u
OBJS   = gb2u.o

all:   $(PROG)

gb2u:  $(OBJS)
       $(CC)$(CFLAGS)$(CPPFLAGS)$(LDFLAGS)$(OBJS)$(LOADLIBES)$(LDLIBS) -o$@

clean:
        rm -rf$(PROG)$(OBJS)

使用Makefile和gb2u.mk的输出

mymtom@FreeBSD:/usr/home/mymtom/src/locale/gb2u$ make clean
rm -rf gb2u gb2u.o
mymtom@FreeBSD:/usr/home/mymtom/src/locale/gb2u$ make
cc -O -pipe  -static -I/usr/local/include -c gb2u.c
cc -O -pipe  -static -I/usr/local/include  -o gb2u gb2u.o  -L/usr/local/lib -liconv
mymtom@FreeBSD:/usr/home/mymtom/src/locale/gb2u$ make -f gb2u.mk clean
rm -rf gb2u gb2u.o
mymtom@FreeBSD:/usr/home/mymtom/src/locale/gb2u$ make -f gb2u.mk
cc -O -pipe  -static -I/usr/local/include -c gb2u.c
cc -O -pipe  -static -I/usr/local/include   -L/usr/local/lib -liconv gb2u.o   -o gb2u
gb2u.o(.text+0x66): In function `main':
: undefined reference to `libiconv_open'
gb2u.o(.text+0x8c): In function `main':
: undefined reference to `libiconv'
gb2u.o(.text+0xec): In function `main':
: undefined reference to `libiconv_close'
*** Error code1

Stop in/usr/home/mymtom/src/locale/gb2u.

gb2u.c

#include<stdio.h>
#include<iconv.h>

int main(void)
...{
       int i, j, m, n, r;

        iconv_t cd;
       char    s[]= "这是附加的消息头，";
       constchar *p;
       char*q;
       char s2[80];

        memset(s2,0,80);

        m=18;
        n=80;
        p= s;
        q= s2;

        cd= iconv_open("UTF-16","GB2312");

        r= iconv(cd,&p,&m, &q,&n);

       if (r>= 0)
       ...{
               for (i= 0; i< (80- n); i++)
               ...{
                        printf("%02x", (unsignedchar)s2[i]);
                }
                printf("");
        }

        iconv_close(cd);

       return0;
}