c++ - Lex 解析器 : (end of buffer or a NUL) segfault

Question

我编写的 lex 解析器一直遇到段错误问题。因此，在构建我的程序时，我在 Makefile 中添加了调试开关 -d。这是我从中得到的输出。

--accepting rule at line 180 ("bxz")
--accepting rule at line 61 (" ")
--accepting rule at line 180 ("e")
--accepting rule at line 68 ("
")
--accepting rule at line 180 ("0L")
--accepting rule at line 193 ("!")
--accepting rule at line 68 ("
")
--accepting rule at line 180 ("0x")
--accepting rule at line 193 (""")
--accepting rule at line 68 ("
")
--(end of buffer or a NUL)
Segmentation fault

当我通过调试工具运行它时，我发现错误发生在 yy_get_next_buffer () at lex.yy.c:1324，这是从我手写的 lex 文件自动生成的 C 文件。我该如何解决这个问题？提前致谢。

Answer 1

(我将其标记为“不可复制”，however it timed-out/aged away 。It has been answered in the comments 。)

@LokiAstari 写道:

It is unlikely that the bug is in the lex code. Therefore it sounds like you are writing off the end of a buffer or abusing memory incorrectly in some other way. Valgrind may help in finding memory errors

@AK 写道:

try to put a newline after your last tokenstring. It might be that your parser tries to find some terminating character after the last symbol.

@ChrisDodd 写道:

You've probably corrupted flex's internal buffer pointer somehow, by writing off the end of an array or some such. If you look at the lex code that is crashing, you might be able to put a data breakpoint on the datastructure that has the incorrect data and figure out who is modifying it