我已经花费了48个小时在这个问题上,但仍然无法解决,在尝试将动态库与其依赖项链接时,我仍然会收到未定义的引用错误,尽管所有导出项都存在,并且成功找到库。
场景:
- libmemory(C++)-使用
extern"C"
导出函数 - libstring(C)-导出函数,从libmemory导入
libmemory成功构建:
$ g++ -shared -fPIC -o ./builds/libmemory.so ...$(OBJECTS)...
libstring编译成功,但链接失败:
$ gcc -shared -fPIC -o ./builds/libstring.so ...$(OBJECTS)... -L./builds -lmemory
./temp/libstring/string.o: In function `STR_duplicate':
string.c:(.text+0x1cb): undefined reference to `MEM_priv_alloc'
./temp/libstring/string.o: In function `STR_duplicate_replace':
string.c:(.text+0x2a0): undefined reference to `MEM_priv_free'
string.c:(.text+0x2bf): undefined reference to `MEM_priv_alloc'
/usr/bin/ld: ./builds/libstring.so: hidden symbol `MEM_priv_free' isn't defined
/usr/bin/ld: final link failed: Bad value
collect2: error: ld returned 1 exit status
验证libmemory导出其符号,并且使用-v
选项在gcc中可以找到该库:
...
attempt to open ./builds/libmemory.so succeeded
-lmemory (./builds/libmemory.so)
...
$ nm -gC ./builds/libmemory.so | grep MEM_
0000000000009178 T MEM_exit
0000000000009343 T MEM_init
00000000000093e9 T MEM_print_leaks
00000000000095be T MEM_priv_alloc
000000000000971d T MEM_priv_free
00000000000099c1 T MEM_priv_realloc
0000000000009d26 T MEM_set_callback_leak
0000000000009d3f T MEM_set_callback_noleak
$ objdump -T ./builds/libmemory.so | grep MEM_
0000000000009d3f g DF .text 0000000000000019 Base MEM_set_callback_noleak
00000000000093e9 g DF .text 00000000000001d5 Base MEM_print_leaks
0000000000009d26 g DF .text 0000000000000019 Base MEM_set_callback_leak
00000000000099c1 g DF .text 0000000000000365 Base MEM_priv_realloc
0000000000009343 g DF .text 00000000000000a6 Base MEM_init
00000000000095be g DF .text 000000000000015f Base MEM_priv_alloc
000000000000971d g DF .text 00000000000002a4 Base MEM_priv_free
0000000000009178 g DF .text 00000000000000a7 Base MEM_exit
$ readelf -Ws ./builds/libmemory.so | grep MEM_
49: 0000000000009d3f 25 FUNC GLOBAL DEFAULT 11 MEM_set_callback_noleak
95: 00000000000093e9 469 FUNC GLOBAL DEFAULT 11 MEM_print_leaks
99: 0000000000009d26 25 FUNC GLOBAL DEFAULT 11 MEM_set_callback_leak
118: 00000000000099c1 869 FUNC GLOBAL DEFAULT 11 MEM_priv_realloc
126: 0000000000009343 166 FUNC GLOBAL DEFAULT 11 MEM_init
145: 00000000000095be 351 FUNC GLOBAL DEFAULT 11 MEM_priv_alloc
192: 000000000000971d 676 FUNC GLOBAL DEFAULT 11 MEM_priv_free
272: 0000000000009178 167 FUNC GLOBAL DEFAULT 11 MEM_exit
103: 0000000000009343 166 FUNC GLOBAL DEFAULT 11 MEM_init
108: 0000000000009178 167 FUNC GLOBAL DEFAULT 11 MEM_exit
148: 0000000000009d3f 25 FUNC GLOBAL DEFAULT 11 MEM_set_callback_noleak
202: 00000000000095be 351 FUNC GLOBAL DEFAULT 11 MEM_priv_alloc
267: 000000000000971d 676 FUNC GLOBAL DEFAULT 11 MEM_priv_free
342: 0000000000009d26 25 FUNC GLOBAL DEFAULT 11 MEM_set_callback_leak
346: 00000000000099c1 869 FUNC GLOBAL DEFAULT 11 MEM_priv_realloc
366: 00000000000093e9 469 FUNC GLOBAL DEFAULT 11 MEM_print_leaks
有什么非常简单的东西我错过了吗?所有其他相关的问题都有简单的答案,比如链接库顺序和使用的路径-但是我已经验证它们已经到位并按预期工作。
调整可见性(-fvisibility)也没有改变任何东西。
使用clang或gcc都会得到相同的结果。
Linux 3.16.0-38-generic gcc版本4.8.4(Ubuntu 4.8.4-2ubuntu1〜14.04.3)
-soname
是否与你的问题有关? - Adrian Colomitchi