[Tinycc-devel] when compile with o2, libtcc goes error on global function pointers

[jee]

I use libtcc to compile code like this:

libtcc code:

typedef int (*tw_type_CLog2Svr__Write_53)(unsigned int val_0,  char val_1, void* val_2, void* val_3);  

tw_type_CLog2Svr__Write_53 g_tw_type_CLog2Svr__Write_53;                                              

int tw_CLog2Svr__Write_53(unsigned int val_0,  char val_1, void* val_2, void* val_3){  

......                

    int val=

    g_tw_type_CLog2Svr__Write_53(val_0, val_1, val_2, val_3);

......

    return val;

}

this code's asm is like this:

0x00007ffff5645980: mov    0x5af(%rip),%r11        # 0x7ffff5645f36

0x00007ffff5645987: mov    (%r11),%r11

0x00007ffff564598a: callq  *%r11

when the code come to 0x00007ffff564598a, it's codedump with SIGSEGV.

the ASM CODE 0x5af is wrong!

1.when i change the tcc code from 

    tw_type_CLog2Svr__Write_53 g_tw_type_CLog2Svr__Write_53;  

    to !!!static!!! tw_type_CLog2Svr__Write.........

 the SIGSEGV disappear。

2.when i round up the tcc_relocate addr to 16, the SIGSEGV disappear。

    like this:

    int iRet = tcc_relocate(m_tcc, NULL);

    m_mem = malloc(iRet + 32);

    void *round_up = (void*)(((size_t)m_mem + 0xf) & ~0xf);

    iRet = tcc_relocate(m_tcc, round_up)

AND,my c code is compiled with O2!