make more use of regmatch_info struct.

regmatch_info is a small struct that is currently directly allocated as a
local var in Perl_regexec_flags(), and has a few fields that maintain part
of the state of the current pattern match. It is passed as an arg to
various functions that regexec_flags() calls, such as regtry().

In some ways its a rival to PL_reg_state, which also maintains state for
the current match, but which is a global variable (whose state needs
saving and restoring whenever the regex engine goes reentrant). It makes
more sense to store state in the regmatch_info struct, and as a first step
in moving more state to there, this commit makes more use of
regmatch_info.

In particular, it makes Perl_re_intuit_start() also allocate such a
struct, so that now *both* the main execution entry points to the regex
engine make use of it. It's also now passed as an arg to more of the static
functions that these two op-level ones call.

Two changes of special note. First, whether S_find_byclass() got called
with a null reginfo pointer of not indicated whether it had been called
from Perl_regexec_flags() (with a valid reginfo pointer), or from
Perl_re_intuit_start() (null pointer). Since they both pass non-null
reginfo pointers now, instead we add an extra field, reginfo->intuit that
indicates who's the top-level caller.

Secondly, to allow in future for various macros to uniformly refer to
values like reginfo->foo, where the structure is actually allocated as a
local var in Perl_regexec_flags(), we change the reginfo from being the
struct itself to being a pointer to the struct, (so Perl_regexec_flags
itself now uses reginfo->foo too rather than reginfo.foo).

In summary, all the above is essentially window dressing that makes no
functional changes to the code, but will facilitate future changes.

1 files changed, 4 insertions, 1 deletions

diff --git a/embed.fnc b/embed.fnc
index 0c9be6af67..ed32623bf8 100644
--- a/embed.fnc
+++ b/embed.fnc
@@ -2069,7 +2069,10 @@ ERs	|bool	|isFOO_lc	|const U8 classnum|const U8 character
 ERs	|bool	|isFOO_utf8_lc	|const U8 classnum|NN const U8* character
 ERs	|I32	|regmatch	|NN regmatch_info *reginfo|NN char *startpos|NN regnode *prog
 ERs	|I32	|regrepeat	|NN regexp *prog|NN char **startposp \
-				|NN const regnode *p|I32 max|int depth \
+				|NN const regnode *p \
+				|NN regmatch_info *const reginfo \
+				|I32 max \
+				|int depth \
 				|bool is_utf8_pat
 ERs	|I32	|regtry		|NN regmatch_info *reginfo|NN char **startposp
 ERs	|bool	|reginclass	|NULLOK regexp * const prog|NN const regnode * const n|NN const U8 * const p\