Replace Perl_sv_setpvf(aTHX_ namesv, "%s/%s", dir, name); in require's

loop over @INC with direct perl API calls that allocate sufficient
memory up front, avoid the need to parse a format string, and avoid
the need to call strlen() on either parameter.

p4raw-id: //depot/perl@32087

diff --git a/pp_ctl.c b/pp_ctl.c
index d925171..0213074 100644 (file)
--- a/pp_ctl.c
+++ b/pp_ctl.c
@@ -3222,6 +3222,7 @@ PP(pp_require)
 #endif
        {
            namesv = newSV(0);
+           sv_upgrade(namesv, SVt_PV);
            for (i = 0; i <= AvFILL(ar); i++) {
                SV * const dirsv = *av_fetch(ar, i, TRUE);
 
@@ -3351,7 +3352,16 @@ PP(pp_require)
                        || (*name == ':' && name[1] != ':' && strchr(name+2, ':'))
 #endif
                  ) {
-                   const char *dir = SvOK(dirsv) ? SvPV_nolen_const(dirsv) : "";
+                   const char *dir;
+                   STRLEN dirlen;
+
+                   if (SvOK(dirsv)) {
+                       dir = SvPV_const(dirsv, dirlen);
+                   } else {
+                       dir = "";
+                       dirlen = 0;
+                   }
+
 #ifdef MACOS_TRADITIONAL
                    char buf1[256];
                    char buf2[256];
@@ -3379,7 +3389,26 @@ PP(pp_require)
                                       "%s\\%s",
                                       dir, name);
 #    else
-                   Perl_sv_setpvf(aTHX_ namesv, "%s/%s", dir, name);
+                   /* The equivalent of                    
+                      Perl_sv_setpvf(aTHX_ namesv, "%s/%s", dir, name);
+                      but without the need to parse the format string, or
+                      call strlen on either pointer, and with the correct
+                      allocation up front.  */
+                   {
+                       char *tmp = SvGROW(namesv, dirlen + len + 2);
+
+                       memcpy(tmp, dir, dirlen);
+                       tmp +=dirlen;
+                       *tmp++ = '/';
+                       /* name came from an SV, so it will have a '\0' at the
+                          end that we can copy as part of this memcpy().  */
+                       memcpy(tmp, name, len + 1);
+
+                       SvCUR_set(namesv, dirlen + len + 1);
+
+                       /* Don't even actually have to turn SvPOK_on() as we
+                          access it directly with SvPVX() below.  */
+                   }
 #    endif
 #  endif
 #endif