[perl #116907] Allow //g matching past 2**31 threshold

Change the internal fields for storing positions so that //g in scalar
context can move past the 2**31 character threshold.  Before this com-
mit, the numbers would wrap, resulting in assertion failures.

The changes in this commit are only enough to get the added test pass-
ing.  Stay tuned for more.

7 files changed, 27 insertions, 18 deletions

diff --git a/embed.fnc b/embed.fnc
index 73951d931c..39b3bb4888 100644
--- a/embed.fnc
+++ b/embed.fnc
@@ -2091,7 +2091,7 @@ Es	|U8	|regtail_study	|NN struct RExC_state_t *pRExC_state \
 #if defined(PERL_IN_REGEXEC_C)
 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	|SSize_t|regmatch	|NN regmatch_info *reginfo|NN char *startpos|NN regnode *prog
 ERs	|I32	|regrepeat	|NN regexp *prog|NN char **startposp \
 				|NN const regnode *p \
 				|NN regmatch_info *const reginfo \
diff --git a/pp_hot.c b/pp_hot.c
index ca285e2907..e07b1b9f1c 100644
--- a/pp_hot.c
+++ b/pp_hot.c
@@ -1326,7 +1326,7 @@ PP(pp_match)
     PMOP *dynpm = pm;
     const char *s;
     const char *strend;
-    I32 curpos = 0; /* initial pos() or current $+[0] */
+    SSize_t curpos = 0; /* initial pos() or current $+[0] */
     I32 global;
     U8 r_flags = 0;
     const char *truebase;			/* Start of string  */
diff --git a/proto.h b/proto.h
index 7326fb805e..d7c9f32fb7 100644
--- a/proto.h
+++ b/proto.h
@@ -7000,7 +7000,7 @@ STATIC bool	S_reginclass(pTHX_ regexp * const prog, const regnode * const n, con
 #define PERL_ARGS_ASSERT_REGINCLASS	\
 	assert(n); assert(p)
 
-STATIC I32	S_regmatch(pTHX_ regmatch_info *reginfo, char *startpos, regnode *prog)
+STATIC SSize_t	S_regmatch(pTHX_ regmatch_info *reginfo, char *startpos, regnode *prog)
 			__attribute__warn_unused_result__
 			__attribute__nonnull__(pTHX_1)
 			__attribute__nonnull__(pTHX_2)
diff --git a/regcomp.c b/regcomp.c
index 69bb66d27a..125a9a2d14 100644
--- a/regcomp.c
+++ b/regcomp.c
@@ -6729,7 +6729,7 @@ Perl_reg_numbered_buff_fetch(pTHX_ REGEXP * const r, const I32 paren,
     struct regexp *const rx = ReANY(r);
     char *s = NULL;
     I32 i = 0;
-    I32 s1, t1;
+    SSize_t s1, t1;
     I32 n = paren;
 
     PERL_ARGS_ASSERT_REG_NUMBERED_BUFF_FETCH;
@@ -6787,7 +6787,7 @@ Perl_reg_numbered_buff_fetch(pTHX_ REGEXP * const r, const I32 paren,
     }          
 
     assert(s >= rx->subbeg);
-    assert(rx->sublen >= (s - rx->subbeg) + i );
+    assert((STRLEN)rx->sublen >= (STRLEN)((s - rx->subbeg) + i) );
     if (i >= 0) {
 #if NO_TAINT_SUPPORT
         sv_setpvn(sv, s, i);
diff --git a/regexec.c b/regexec.c
index a1d61a5d9c..29991b5820 100644
--- a/regexec.c
+++ b/regexec.c
@@ -296,8 +296,8 @@ S_regcppush(pTHX_ const regexp *rex, I32 parenfloor, U32 maxopenparen)
     );
     for (p = parenfloor+1; p <= (I32)maxopenparen;  p++) {
 /* REGCP_PARENS_ELEMS are pushed per pairs of parentheses. */
-	SSPUSHINT(rex->offs[p].end);
-	SSPUSHINT(rex->offs[p].start);
+	SSPUSHIV(rex->offs[p].end);
+	SSPUSHIV(rex->offs[p].start);
 	SSPUSHINT(rex->offs[p].start_tmp);
 	DEBUG_BUFFERS_r(PerlIO_printf(Perl_debug_log,
 	    "    \\%"UVuf": %"IVdf"(%"IVdf")..%"IVdf"\n",
@@ -371,8 +371,8 @@ S_regcppop(pTHX_ regexp *rex, U32 *maxopenparen_p)
     for ( ; i > 0; i -= REGCP_PAREN_ELEMS) {
 	I32 tmps;
 	rex->offs[paren].start_tmp = SSPOPINT;
-	rex->offs[paren].start = SSPOPINT;
-	tmps = SSPOPINT;
+	rex->offs[paren].start = SSPOPIV;
+	tmps = SSPOPIV;
 	if (paren <= rex->lastparen)
 	    rex->offs[paren].end = tmps;
 	DEBUG_BUFFERS_r( PerlIO_printf(Perl_debug_log,
@@ -2097,8 +2097,8 @@ S_reg_set_capture_string(pTHX_ REGEXP * const rx,
         } else
 #endif
         {
-            I32 min = 0;
-            I32 max = strend - strbeg;
+            SSize_t min = 0;
+            SSize_t max = strend - strbeg;
             I32 sublen;
 
             if (    (flags & REXEC_COPY_SKIP_POST)
@@ -2938,7 +2938,7 @@ S_regtry(pTHX_ regmatch_info *reginfo, char **startposp)
     CHECKPOINT lastcp;
     REGEXP *const rx = reginfo->prog;
     regexp *const prog = ReANY(rx);
-    I32 result;
+    SSize_t result;
     RXi_GET_DECL(prog,progi);
     GET_RE_DEBUG_FLAGS_DECL;
 
@@ -3583,7 +3583,7 @@ S_setup_EXACTISH_ST_c1_c2(pTHX_ const regnode * const text_node, int *c1p,
 }
 
 /* returns -1 on failure, $+[0] on success */
-STATIC I32
+STATIC SSize_t
 S_regmatch(pTHX_ regmatch_info *reginfo, char *startpos, regnode *prog)
 {
 #if PERL_VERSION < 9 && !defined(PERL_CORE)
diff --git a/regexp.h b/regexp.h
index fd6425f403..c8d03e3758 100644
--- a/regexp.h
+++ b/regexp.h
@@ -55,8 +55,8 @@ struct reg_substr_data {
 /* offsets within a string of a particular /(.)/ capture */
 
 typedef struct regexp_paren_pair {
-    I32 start;
-    I32 end;
+    SSize_t start;
+    SSize_t end;
     /* 'start_tmp' records a new opening position before the matching end
      * has been found, so that the old start and end values are still
      * valid, e.g.
@@ -503,7 +503,8 @@ get_regex_charset_name(const U32 flags, STRLEN* const lenp)
 #define RX_SAVED_COPY(prog)	(ReANY(prog)->saved_copy)
 /* last match was zero-length */
 #define RX_ZERO_LEN(prog) \
-        (RX_OFFS(prog)[0].start + RX_GOFS(prog) == (UV)RX_OFFS(prog)[0].end)
+        (RX_OFFS(prog)[0].start + (SSize_t)RX_GOFS(prog) \
+          == RX_OFFS(prog)[0].end)
 
 #endif /* PLUGGABLE_RE_EXTENSION */
 
diff --git a/t/bigmem/regexp.t b/t/bigmem/regexp.t
index ef029fbd9b..ef74e59ab7 100644
--- a/t/bigmem/regexp.t
+++ b/t/bigmem/regexp.t
@@ -12,11 +12,19 @@ $ENV{PERL_TEST_MEMORY} >= 2
 $Config{ptrsize} >= 8
     or skip_all("Need 64-bit pointers for this test");
 
-plan(2);
+plan(3);
 
 # [perl #116907]
 # ${\2} to defeat constant folding, which in this case actually slows
 # things down
-my $x=" "x(${\2}**31);
+my $x=" "x(${\2}**31) . "abcdefg";
 ok $x =~ /./, 'match against long string succeeded';
 is "$-[0]-$+[0]", '0-1', '@-/@+ after match against long string';
+
+pos $x = 2**31-1;
+my $result;
+for(1..5) {
+    $x =~ /./g;
+    $result .= "$&-";
+}
+is $result," -a-b-c-d-", 'scalar //g hopping past the 2**31 threshold';