我学习C++和正在与装载在Linux(。所以)一个共享库试验。负载在C共享库++使段错误
我得到一个分段错误,当我运行下面的代码。
当我尝试使用Valgrind的运行控制台应用程序,我得到如下:
valgrind ./TestLoadSo --leak-check=full -v
==26828== Memcheck, a memory error detector
==26828== Copyright (C) 2002-2015, and GNU GPL'd, by Julian Seward et al.
==26828== Using Valgrind-3.12.0 and LibVEX; rerun with -h for copyright info
==26828== Command: ./TestLoadSo --leak-check=full -v
==26828==
!!!Hello World!!!
==26828== Jump to the invalid address stated on the next line
==26828== at 0x0: ???
==26828== by 0x53E63F0: (below main) (libc-start.c:291)
==26828== Address 0x0 is not stack'd, malloc'd or (recently) free'd
==26828==
==26828==
==26828== Process terminating with default action of signal 11 (SIGSEGV)
==26828== Bad permissions for mapped region at address 0x0
==26828== at 0x0: ???
==26828== by 0x53E63F0: (below main) (libc-start.c:291)
==26828==
==26828== HEAP SUMMARY:
==26828== in use at exit: 3,126 bytes in 9 blocks
==26828== total heap usage: 13 allocs, 4 frees, 76,998 bytes allocated
==26828==
==26828== LEAK SUMMARY:
==26828== definitely lost: 0 bytes in 0 blocks
==26828== indirectly lost: 0 bytes in 0 blocks
==26828== possibly lost: 0 bytes in 0 blocks
==26828== still reachable: 3,126 bytes in 9 blocks
==26828== suppressed: 0 bytes in 0 blocks
==26828== Rerun with --leak-check=full to see details of leaked memory
==26828==
==26828== For counts of detected and suppressed errors, rerun with: -v
==26828== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0)
[1] 26828 segmentation fault (core dumped) valgrind ./TestLoadSo --leak-check=full -v
C++主类
extern "C" typedef char* (*helloWorld_t)();
int main() {
void* handle = dlopen("./libMyLib.dll.so", RTLD_LAZY);
if (!handle) {
cerr << "Cannot open library: " << dlerror() << '\n';
return 1;
}
helloWorld_t hello = (helloWorld_t)dlsym(handle, "helloWorld");
const char * tmp = hello();
printf("\n%s",tmp);
return 0;
}
的外部函数是:
extern "C++" char* helloWorld() {
char str[25];
strcpy(str, "HelloWorld");
}
如果我使用extern "C"
我得到一个汇编错误:
error: conflicting declaration of ‘char* helloWorld()’ with ‘C’ linkage
extern "C" char* helloWorld() {
它真的不清楚我在哪里出错。
'helloWorld'函数的实现是什么?还可以使用-O0编译您的程序以从valgrind获得更好的信息。 – Serge
'跳转到下一行指出的无效地址'.so中似乎没有* helloWorld *符号。你不应该使用'extern“C”'而不是'extern“C++”'? – freakish
您的外部helloWorld也不会返回任何内容。如果你实际上有'return str',那么这将是一个问题 - 你不应该返回指向栈变量的指针 – lxop