Perl_sv_vcatpvfn_flags: split the 'need' local var

The 'need' local var has a wide scope (over 500 lines), and is used for
two separate purposes. Split it into two separate vars. One remains wide
scope, but is just used to calculate the new value of PL_efloatsize. Rename
that one to 'float_need'.

For the second use, introduce a new scope of just 6 lines with its own
'need' variable'.

This should make no functional difference but makes the code slightly
easier to understand and analyse.

diff --git a/sv.c b/sv.c
index 4c3936b..14b8384 100644 (file)
--- a/sv.c
+++ b/sv.c
@@ -11628,7 +11628,7 @@ Perl_sv_vcatpvfn_flags(pTHX_ SV *const sv, const char *const pat, const STRLEN p
 #endif
         NV nv;
        STRLEN have;
-       STRLEN need;
+       STRLEN float_need; /* what PL_efloatsize needs to become */
        STRLEN gap;
        const char *dotstr = ".";
        STRLEN dotstrlen = 1;
@@ -12407,7 +12407,7 @@ Perl_sv_vcatpvfn_flags(pTHX_ SV *const sv, const char *const pat, const STRLEN p
                 NV_TO_FV(nv, fv);
             }
 
-           need = 0;
+           float_need = 0;
            /* frexp() (or frexpl) has some unspecified behaviour for
              * nan/inf/-inf, so let's avoid calling that on non-finites. */
            if (isALPHA_FOLD_NE(c, 'e') && FV_ISFINITE(fv)) {
@@ -12425,7 +12425,7 @@ Perl_sv_vcatpvfn_flags(pTHX_ SV *const sv, const char *const pat, const STRLEN p
                      * exponent.  Secondly, for the reasonably common
                      * long doubles case, the "80-bit extended", two
                      * or six bytes of the NV are unused. */
-                    need +=
+                    float_need +=
                         (fv < 0) ? 1 : 0 + /* possible unary minus */
                         2 + /* "0x" */
                         1 + /* the very unlikely carry */
@@ -12444,30 +12444,30 @@ Perl_sv_vcatpvfn_flags(pTHX_ SV *const sv, const char *const pat, const STRLEN p
                      * See the definition of DOUBLEDOUBLE_MAXBITS.
                      *
                      * Need 2 hexdigits for each byte. */
-                    need += (DOUBLEDOUBLE_MAXBITS/8 + 1) * 2;
+                    float_need += (DOUBLEDOUBLE_MAXBITS/8 + 1) * 2;
                     /* the size for the exponent already added */
 #endif
 #ifdef USE_LOCALE_NUMERIC
                         STORE_LC_NUMERIC_SET_TO_NEEDED();
                         if (PL_numeric_radix_sv && IN_LC(LC_NUMERIC))
-                            need += SvLEN(PL_numeric_radix_sv);
+                            float_need += SvLEN(PL_numeric_radix_sv);
                         RESTORE_LC_NUMERIC();
 #endif
                 }
                 else if (i > 0) {
-                    need = BIT_DIGITS(i);
+                    float_need = BIT_DIGITS(i);
                 } /* if i < 0, the number of digits is hard to predict. */
            }
 
             {
                 STRLEN pr = has_precis ? precis : 6; /* known default */
-                if (need >= ((STRLEN)~0) - pr)
+                if (float_need >= ((STRLEN)~0) - pr)
                     croak_memory_wrap();
-                need += pr;
+                float_need += pr;
             }
 
-           if (need < width)
-               need = width;
+           if (float_need < width)
+               float_need = width;
 
 #ifdef HAS_LDBL_SPRINTF_BUG
            /* This is to try to fix a bug with irix/nonstop-ux/powerux and
@@ -12501,7 +12501,7 @@ Perl_sv_vcatpvfn_flags(pTHX_ SV *const sv, const char *const pat, const STRLEN p
 
            if ((intsize == 'q') && (c == 'f') &&
                ((fv < MY_DBL_MAX_BUG) && (fv > -MY_DBL_MAX_BUG)) &&
-               (need < DBL_DIG)) {
+               (float_need < DBL_DIG)) {
                /* it's going to be short enough that
                 * long double precision is not needed */
 
@@ -12535,12 +12535,12 @@ Perl_sv_vcatpvfn_flags(pTHX_ SV *const sv, const char *const pat, const STRLEN p
 
 #endif /* HAS_LDBL_SPRINTF_BUG */
 
-            if (need >= ((STRLEN)~0) - 40)
+            if (float_need >= ((STRLEN)~0) - 40)
                 croak_memory_wrap();
-           need += 40; /* fudge factor */
-           if (PL_efloatsize < need) {
+           float_need += 40; /* fudge factor */
+           if (PL_efloatsize < float_need) {
                Safefree(PL_efloatbuf);
-               PL_efloatsize = need;
+               PL_efloatsize = float_need;
                Newx(PL_efloatbuf, PL_efloatsize, char);
                PL_efloatbuf[0] = '\0';
            }
@@ -13047,12 +13047,15 @@ Perl_sv_vcatpvfn_flags(pTHX_ SV *const sv, const char *const pat, const STRLEN p
        if (have < zeros)
            croak_memory_wrap();
 
-       need = (have > width ? have : width);
-       gap = need - have;
+        {
+            STRLEN need = (have > width ? have : width);
+            gap = need - have;
+
+            if (need >= (((STRLEN)~0) - SvCUR(sv) - dotstrlen - 1))
+                croak_memory_wrap();
+            SvGROW(sv, SvCUR(sv) + need + dotstrlen + 1);
+        }
 
-       if (need >= (((STRLEN)~0) - SvCUR(sv) - dotstrlen - 1))
-           croak_memory_wrap();
-       SvGROW(sv, SvCUR(sv) + need + dotstrlen + 1);
        p = SvEND(sv);
        if (esignlen && fill == '0') {
            int i;