Hi, I'm a total beginner in PCRE2, now I'm "playing" with the code.
I reviewed the man pages and documentation. If I'm not mistaken, PCRE2 supports JIT (on most popular architectures - eg. AMD64), but the user has to turn it on. The pcre2jit man page says *In some circumstances you may need to call additional functions. These are described in the section entitled "Controlling the JIT stack" below.* Is there any way to decide, in which case do I need to use those functions? I mean the patterns are totally unknown to me, it could be very complex or can be very simple. Now I try this solution: https://github.com/digitalwave/msc_retest/blob/pcre2support-jit/src/regex.cc#L161-L195 I chose 1MB, because man page says *A maximum stack size of 512KiB to 1MiB should be more than enough for any pattern.* Do I need to add the manual stack allocation? Or would be enough just simple call the pcre2_jit_compile(re, PCRE2_JIT_COMPLETE); and if the call fails, then match won't use JIT - but the application won't terminate? Calling the pcre2_jit_stack_create(1, 1024 * 1024, NULL); allocates the whole 1MB of memory? I just ask, because I showed some details about compiled regex in that code, and it says: DETAILED INFORMATION: ===================== PCRE2_INFO_BACKREFMAX: 0 PCRE2_INFO_CAPTURECOUNT: 0 PCRE2_INFO_DEPTHLIMIT: 4294967295 PCRE2_INFO_JITSIZE: 76976 PCRE2_INFO_MINLENGTH: 3 PCRE2_INFO_MATCHLIMIT: 4294967295 PCRE2_INFO_SIZE: 20149 The PCRE2_INFO_JITSIZE: 76976 means it uses almost 77kB of 1MB, but the 1MB has been allocated? So if I have 200 regexes, then it means the application needs +200MB memory? Thanks for your helps, a. -- ## List details at https://lists.exim.org/mailman/listinfo/pcre-dev
