红宝石64位AIX编译正则表达式的限制 [英] Regex limit in ruby 64 bit aix compilation

问题描述

我编红宝石64位在AIX箱。 似乎没有要当我使用一些特定的规律EX pressions在我的code除外的任何问题。 下面是一个例子：

I have compiled ruby 64 bit on an AIX Box. There doesn't seem to be any issue except when I use some specific regular expressions in my code. Here is an example:

/([0-9]){1000}/.match("2")

结果：

RegexpError: too big quantifier in {,}: /([0-9]*){1000}/

当我尝试减少重复次数，似乎工作。

When I try reducing the number of repetitions, it seems to work.

我试图挖成红宝石code。但无法明白其中的道理。 这是一些依赖或限制，我们在AIX / 64位红宝石？

I tried digging into the ruby code. But could not understand the reason. Is this some dependency or restriction that we have in AIX/64 bit ruby?

在此先感谢：）

推荐答案

我几乎立刻就找到了答案。

I almost immediately found the answer.

第一件事是在Ruby源$ C ​​$下被抛出的错误进行搜索。我发现，regex.h负责这一点。

The first thing I did was to search in the ruby source code for the error being thrown. I found that regex.h was responsible for this.

在regex.h中，code流量是这样的：

In regex.h, the code flow is something like this:

/* Maximum number of duplicates an interval can allow.  */
#ifndef RE_DUP_MAX
#define RE_DUP_MAX  ((1 << 15) - 1)
#endif

现在这里的问题是RE_DUP_MAX。在AIX中，相同的常已在/ usr中定义的某个地方/有。我搜索了一下，发现在

Now the problem here is RE_DUP_MAX. On AIX box, the same constant has been defined somewhere in /usr/include. I searched for it and found in

/usr/include/NLregexp.h
/usr/include/sys/limits.h
/usr/include/unistd.h

我不知道这三个正在使用（最有可能NLregexp.h）。在这些头，RE_DUP_MAX的值已被设置为255！因此，有一个帽放置在正则表达式的重复数！

I am not sure which of the three is being used(most probably NLregexp.h). In these headers, the value of RE_DUP_MAX has been set to 255! So there is a cap placed on the number of repetitions of a regex!

总之，原因是编译取系统定义的值比我们在regex.h定义！

In short, the reason is the compilation taking the system defined value than that we define in regex.h!

因此​​，问题是解决了重新分配RE_DUP_MAX的regex.h价值 即

Hence the issue was solved by reassigning the value of RE_DUP_MAX in regex.h i.e

# ifdef RE_DUP_MAX
# undef RE_DUP_MAX                                                                                            
# endif

# define RE_DUP_MAX ((1 << 15) - 1)

干杯！

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