导致此链接失败的原因（未定义参考）？

Question

我刚换我的dev的机器从Gentoo用来Arch Linux的，当我尝试编译我的项目的一个新的构建，连接失败：

clang -O0 -g -pipe -Wall -DDEBUG -o slug announce.o bitfield.o main.o metadata.o network.o parser.o peer.o piece.o scheduler.o torrent.o url.o util.o -I. -lssl -lm -lcurl -levent 
/usr/bin/ld.gold: metadata.o: in function get_info_hash:metadata.c:186: error: undefined reference to 'SHA1_Init' 
/usr/bin/ld.gold: metadata.o: in function get_info_hash:metadata.c:187: error: undefined reference to 'SHA1_Update' 
/usr/bin/ld.gold: metadata.o: in function get_info_hash:metadata.c:188: error: undefined reference to 'SHA1_Final' 
/usr/bin/ld.gold: piece.o: in function verify_piece:piece.c:40: error: undefined reference to 'SHA1_Init' 
/usr/bin/ld.gold: piece.o: in function verify_piece:piece.c:41: error: undefined reference to 'SHA1_Update' 
/usr/bin/ld.gold: piece.o: in function verify_piece:piece.c:42: error: undefined reference to 'SHA1_Final' 
clang: error: linker command failed with exit code 1 (use -v to see invocation) 
make: *** [slug] Error 1 

整个源是在GitHub上：https://github.com/robertseaton/slug。

Answer 1

看起来你错过-lcrypto

Answer 2

从我的经验，-lssl或-lcrypto位置可能是问题的根源。尝试将-lcrypto选项推到gcc选项的末尾，或在输入对象文件之前。