C查找替换不起作用

以下是不起作用的函数:

char * insert_symtab(char *buf)
{
  char *ret = (char *)malloc(strlen(buf) + 512);
  char *tmp = NULL;
  char *repl = NULL;
  char obuf[32]; //for converting int to hex
  Symtab_struct *cursym;
  lineQueue *lq = readlines(buf);
  int i;
  strcpy(ret, "");
  while (!lq->empty())
  {
    tmp = getlinefromqueue(lq);
    for (i = 0; (cursym = symtab->findNodeByNumber(i)) != NULL; i++)
    {
        sprintf(obuf, "0x%04x", cursym->sym_location);
        //printf("-->looking for %s\n", cursym->sym_name);
        if ((repl = strstr(tmp, cursym->sym_name)) != NULL)
        {
            printf("---->Found %s\n", cursym->sym_name);
            strncpy (repl, obuf, strlen(cursym->sym_name));
        }
    }
    strcat(ret, tmp);
    strcat(ret, "\n");
  }
  return ret;
}

这样运行时,我得到以下输出:

[WARN process_includes] Cannot find file included 1test2.asm
[DEBUG build_symtab] Inserting symbol  to location 0x0000
[DEBUG build_symtab] Inserting symbol $start to location 0x0008
[DEBUG build_symtab] Inserting symbol $eight to location 0x0008
[WARN in Symtab::insertNode] Redefinition of symbol $start is ignored
;include '1test2.asm'
:start:
mov a b
add a b
:eight:
:start:
sub a b
$start

如果我进去换衣服

if ((repl = strstr(tmp, cursym->sym_name)) != NULL)
to
if ((repl = strstr(tmp, "$start")) != NULL)

我得到以下输出:

[WARN process_includes] Cannot find file included 1test2.asm
[DEBUG build_symtab] Inserting symbol  to location 0x0000
[DEBUG build_symtab] Inserting symbol $start to location 0x0008
[DEBUG build_symtab] Inserting symbol $eight to location 0x0008
[WARN in Symtab::insertNode] Redefinition of symbol $start is ignored
---->Found $start
;include '1test2.asm'
:start:
mov a b
add a b
:eight:
:start:
sub a b
0x0000

应该是这样的。附件是整个项目的pastebin链接:

main.cpp: http://pastebin.com/AiDCbsCt

符号.h: http://pastebin.com/Kmcn6NzV

符号.cpp: http://pastebin.com/mxtPL1d2

有什么想法吗?