gentoo-overlay/dev-libs/libpcre/metadata.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE pkgmetadata SYSTEM "http://www.gentoo.org/dtd/metadata.dtd">
<pkgmetadata>
  <herd>base-system</herd>
  <use>
    <flag name='bzip2'>
      Add support for pcregrep command to search within
      bzip2-compressed files, through <pkg>sys-libs/zlib</pkg>.
    </flag>

    <flag name='jit'>
      Enable Just-In-Time compilation of regexp bytecode to machine
      code, through the SLJIT compiler. This feature might conflict
      with security mitigation strategies such as NX/PaX as enabled by
      Gentoo Hardened.
    </flag>

    <flag name='pcre16'>
      Build 16 bit PCRE library.
    </flag>

    <flag name='readline'>
      Add support for command line editing to pcretest, through
      <pkg>sys-libs/readline</pkg>.
    </flag>

    <flag name='recursion-limit'>
      Limit match recursion to 8192; if disabled, the default limit is
      used, which is the same as the match limit.
    </flag>

    <flag name='zlib'>
      Add support for pcregrep command to search within
      gzip-compressed files, through <pkg>app-arch/gzip</pkg>.
    </flag>
  </use>
</pkgmetadata>