用clang编译SPEC2006 过程中的问题（与gcc，ld相关）

1. 重复定义__strcspn_c1

编译401.bzip2时错误

/usr/include/bits/string2.h:972: multiple definition of `__strcspn_c1'

bgm.o:/usr/include/bits/string2.h:972: first defined here

dinkini.o: In function `__strcspn_c2':

/usr/include/bits/string2.h:983: multiple definition of `__strcspn_c2'

bgm.o:/usr/include/bits/string2.h:983: first defined here

dinkini.o: In function `__strcspn_c3':

/usr/include/bits/string2.h:996: multiple definition of `__strcspn_c3'

bgm.o:/usr/include/bits/string2.h:996: first defined here

分析：该问题一般是在使用较老版本的gcc库时碰到，例如在centos操作系统平台上，gcc是4.1.2时会碰到该问题，问题原因SPEC中部分代码时C89，但是clang默认版本为CC89，从而导致出现该错误。更详细解释可以参考：
http://lists.cs.uiuc.edu/pipermail/llvmdev/2009-December/027958.html
GCC从4.5开始，才完全支持C99.
https://gcc.gnu.org/c99status.html
解决：在编译选项中添加-std=gnu89

另外, 429.mcf， 433.milc， 445.gobmk等也存在同样问题

2. 编译403.gcc是的重复定义错误

错误信息：

mp/concat-yeQL2V.o: In function `gnu_dev_major':

/usr/include/sys/sysmacros.h:44: multiple definition of `gnu_dev_major'

/tmp/alloca-YSgYzY.o:/usr/include/sys/sysmacros.h:44: first defined here

/tmp/concat-yeQL2V.o: In function `gnu_dev_makedev':

/usr/include/sys/sysmacros.h:56: multiple definition of `gnu_dev_makedev'

/tmp/alloca-YSgYzY.o:/usr/include/sys/sysmacros.h:56: first defined here

/tmp/concat-yeQL2V.o: In function `gnu_dev_minor':

/usr/include/sys/sysmacros.h:50: multiple definition of `gnu_dev_minor'

/tmp/alloca-YSgYzY.o:/usr/include/sys/sysmacros.h:50: first defined here

/usr/bin/ld: Dwarf Error: Invalid or unhandled FORM value: 25.

/usr/bin/ld: Dwarf Error: Invalid or unhandled FORM value: 25.

/usr/bin/ld: Dwarf Error: Invalid or unhandled FORM value: 25.

/usr/bin/ld: Dwarf Error: Invalid or unhandled FORM value: 25.

/usr/bin/ld: Dwarf Error: Invalid or unhandled FORM value: 25.

/usr/bin/ld: Dwarf Error: Invalid or unhandled FORM value: 25.

/usr/bin/ld: Dwarf Error: Invalid or unhandled FORM value: 25.

/usr/bin/ld: Dwarf Error: Invalid or unhandled FORM value: 25.

/usr/bin/ld: Dwarf Error: Invalid or unhandled FORM value: 25.

/usr/bin/ld: Dwarf Error: Invalid or unhandled FORM value: 25.

/tmp/getpwd-UxjZIi.o: In function `fstat':

/usr/include/sys/stat.h:449: multiple definition of `fstat'

/tmp/c-parse-7tFGiF.o:/usr/include/sys/stat.h:449: first defined here

/tmp/getpwd-UxjZIi.o: In function `fstat64':

/usr/include/sys/stat.h:498: multiple definition of `fstat64'

/tmp/c-parse-7tFGiF.o:/usr/include/sys/stat.h:498: first defined here

/tmp/getpwd-UxjZIi.o: In function `fstatat':

分析：ld版本过旧，当前版本是

GNU ld version 2.17.50.0.6-9.el5 20061020
Copyright 2005 Free Software Foundation, Inc.
This program is free software; you may redistribute it under the terms of
the GNU General Public License. This program has absolutely no warranty.

更新后版本是

GNU ld (GNU Binutils) 2.20.1.20100303

并将该链接器添加到对应路径中，例如PATH和LD_LIBRARY_PATH

问题解决。

如果还需要编译其他C++程序，那么最好安装binutils 2.25.
http://ftp.gnu.org/gnu/binutils/