Hi, I would simply use the PCRE version number to detect jit_exec at compile time:
#if (PCRE_MAJOR > 8 || (PCRE_MAJOR == 8 && PCRE_MINOR >= 32)) #define PCRE_JIT_EXEC_AVAILABLE #endif Regards, Zoltan -------- Eredeti levél -------- Feladó: Ævar Arnfjörð Bjarmason < avarab@gmail.com (Link -> mailto:avarab@gmail.com) > Dátum: 2017 május 31 18:44:28 Tárgy: How do I support pcre1 JIT on all versions? Címzett: Philip Hazel < pcre-dev@exim.org (Link -> mailto:pcre-dev@exim.org) My patch to add JIT support to Git with the PCRE v1 API works all the way down to PCRE version 7.5 (the last one I could get to compile), but *only* if I compile the versions that support JIT with --enable-jit, not --disable-jit. The problem is that both PCRE_CONFIG_JIT and PCRE_STUDY_JIT_COMPILE will be defined even when JIT support isn't enabled, so I can't use them to check if I should ifdef a codepath that uses pcre_jit_exec() into existence, if a newer pcre library is compiled ith --disable-jit the git build will fail at link time since there's no such symbol. I have a hack around this, which as far as I can tell is the only way to do this, but I'd welcome a different way. Ever since the JIT support was added back in 2011 these macros have been conditionally defined: +#ifdef SUPPORT_JIT + +/* All-in-one: Since we use the JIT compiler only from here, +we just include it. This way we don't need to touch the build +system files. */ + +#define SLJIT_CONFIG_AUTO 1 +#define SLJIT_VERBOSE 0 +#define SLJIT_DEBUG 0 + +#include "sljit/sljitLir.c" + +#if defined SLJIT_CONFIG_UNSUPPORTED && SLJIT_CONFIG_UNSUPPORTED +#error "Unsupported architecture" +#endif So I'm guarding code that takes that pcre_exec_jit() codepath with `#ifdef SLJIT_CONFIG_AUTO`. This works on all pcre versions, and I'm going to use that unless someone tells me otherwise. Also, please apply my patch to the pcrejit docs for a related thing: https://bugs.exim.org/show_bug.cgi?id=2121 Depending on the follow-ups to this post I'll submit another change to the docs to note how to support JIT on PCRE v1 with all combinations of versions & --{disable,enable}-jit. -- ## List details at https://lists.exim.org/mailman/listinfo/pcre-dev
