[perl #36207] UTF8/Latin 1/i regexp "Malformed character" warning
[p5sagit/p5-mst-13.2.git] / perl.c
diff --git a/perl.c b/perl.c
index 45b8625..4bafb31 100644 (file)
--- a/perl.c
+++ b/perl.c
@@ -92,6 +92,21 @@ char *nw_get_sitelib(const char *pl);
 #include <unistd.h>
 #endif
 
+#ifdef DEBUG_LEAKING_SCALARS_FORK_DUMP
+#  ifdef I_SYS_WAIT
+#   include <sys/wait.h>
+#  endif
+#  ifdef I_SYSUIO
+#    include <sys/uio.h>
+#  endif
+
+union control_un {
+  struct cmsghdr cm;
+  char control[CMSG_SPACE(sizeof(int))];
+};
+
+#endif
+
 #ifdef __BEOS__
 #  define HZ 1000000
 #endif
@@ -203,6 +218,7 @@ void
 perl_construct(pTHXx)
 {
     dVAR;
+    PERL_UNUSED_ARG(my_perl);
 #ifdef MULTIPLICITY
     init_interp();
     PL_perl_destruct_level = 1;
@@ -316,12 +332,8 @@ perl_construct(pTHXx)
 
     PL_stashcache = newHV();
 
-    PL_patchlevel = newSVpv(
-           Perl_form(aTHX_ "%d.%d.%d",
-           (int)PERL_REVISION,
-           (int)PERL_VERSION,
-           (int)PERL_SUBVERSION ), 0
-    );
+    PL_patchlevel = Perl_newSVpvf(aTHX_ "%d.%d.%d", (int)PERL_REVISION,
+                                 (int)PERL_VERSION, (int)PERL_SUBVERSION);
 
 #ifdef HAS_MMAP
     if (!PL_mmap_page_size) {
@@ -383,6 +395,104 @@ Perl_nothreadhook(pTHX)
     return 0;
 }
 
+#ifdef DEBUG_LEAKING_SCALARS_FORK_DUMP
+void
+Perl_dump_sv_child(pTHX_ SV *sv)
+{
+    ssize_t got;
+    const int sock = PL_dumper_fd;
+    const int debug_fd = PerlIO_fileno(Perl_debug_log);
+    union control_un control;
+    struct msghdr msg;
+    struct iovec vec[2];
+    struct cmsghdr *cmptr;
+    int returned_errno;
+    unsigned char buffer[256];
+
+    if(sock == -1 || debug_fd == -1)
+       return;
+
+    PerlIO_flush(Perl_debug_log);
+
+    /* All these shenanigans are to pass a file descriptor over to our child for
+       it to dump out to.  We can't let it hold open the file descriptor when it
+       forks, as the file descriptor it will dump to can turn out to be one end
+       of pipe that some other process will wait on for EOF. (So as it would
+       be open, the wait would be forever.  */
+
+    msg.msg_control = control.control;
+    msg.msg_controllen = sizeof(control.control);
+    /* We're a connected socket so we don't need a destination  */
+    msg.msg_name = NULL;
+    msg.msg_namelen = 0;
+    msg.msg_iov = vec;
+    msg.msg_iovlen = 1;
+
+    cmptr = CMSG_FIRSTHDR(&msg);
+    cmptr->cmsg_len = CMSG_LEN(sizeof(int));
+    cmptr->cmsg_level = SOL_SOCKET;
+    cmptr->cmsg_type = SCM_RIGHTS;
+    *((int *)CMSG_DATA(cmptr)) = 1;
+
+    vec[0].iov_base = (void*)&sv;
+    vec[0].iov_len = sizeof(sv);
+    got = sendmsg(sock, &msg, 0);
+
+    if(got < 0) {
+       perror("Debug leaking scalars parent sendmsg failed");
+       abort();
+    }
+    if(got < sizeof(sv)) {
+       perror("Debug leaking scalars parent short sendmsg");
+       abort();
+    }
+
+    /* Return protocol is
+       int:            errno value
+       unsigned char:  length of location string (0 for empty)
+       unsigned char*: string (not terminated)
+    */
+    vec[0].iov_base = (void*)&returned_errno;
+    vec[0].iov_len = sizeof(returned_errno);
+    vec[1].iov_base = buffer;
+    vec[1].iov_len = 1;
+
+    got = readv(sock, vec, 2);
+
+    if(got < 0) {
+       perror("Debug leaking scalars parent read failed");
+       PerlIO_flush(PerlIO_stderr());
+       abort();
+    }
+    if(got < sizeof(returned_errno) + 1) {
+       perror("Debug leaking scalars parent short read");
+       PerlIO_flush(PerlIO_stderr());
+       abort();
+    }
+
+    if (*buffer) {
+       got = read(sock, buffer + 1, *buffer);
+       if(got < 0) {
+           perror("Debug leaking scalars parent read 2 failed");
+           PerlIO_flush(PerlIO_stderr());
+           abort();
+       }
+
+       if(got < *buffer) {
+           perror("Debug leaking scalars parent short read 2");
+           PerlIO_flush(PerlIO_stderr());
+           abort();
+       }
+    }
+
+    if (returned_errno || *buffer) {
+       Perl_warn(aTHX_ "Debug leaking scalars child failed%s%.*s with errno"
+                 " %d: %s", (*buffer ? " at " : ""), (int) *buffer, buffer + 1,
+                 returned_errno, strerror(returned_errno));
+    }
+}
+#endif
+
 /*
 =for apidoc perl_destruct
 
@@ -397,6 +507,11 @@ perl_destruct(pTHXx)
     dVAR;
     volatile int destruct_level;  /* 0=none, 1=full, 2=full with checks */
     HV *hv;
+#ifdef DEBUG_LEAKING_SCALARS_FORK_DUMP
+    pid_t child;
+#endif
+
+    PERL_UNUSED_ARG(my_perl);
 
     /* wait for all pseudo-forked children to finish */
     PERL_WAIT_FOR_CHILDREN;
@@ -404,8 +519,8 @@ perl_destruct(pTHXx)
     destruct_level = PL_perl_destruct_level;
 #ifdef DEBUGGING
     {
-       const char *s;
-       if ((s = PerlEnv_getenv("PERL_DESTRUCT_LEVEL"))) {
+       const char * const s = PerlEnv_getenv("PERL_DESTRUCT_LEVEL");
+       if (s) {
             const int i = atoi(s);
            if (destruct_level < i)
                destruct_level = i;
@@ -418,6 +533,7 @@ perl_destruct(pTHXx)
         int x = 0;
 
         JMPENV_PUSH(x);
+       PERL_UNUSED_VAR(x);
         if (PL_endav && !PL_minus_c)
             call_list(PL_scopestack_ix, PL_endav);
         JMPENV_POP;
@@ -433,9 +549,168 @@ perl_destruct(pTHXx)
         return STATUS_NATIVE_EXPORT;
     }
 
+#ifdef DEBUG_LEAKING_SCALARS_FORK_DUMP
+    if (destruct_level != 0) {
+       /* Fork here to create a child. Our child's job is to preserve the
+          state of scalars prior to destruction, so that we can instruct it
+          to dump any scalars that we later find have leaked.
+          There's no subtlety in this code - it assumes POSIX, and it doesn't
+          fail gracefully  */
+       int fd[2];
+
+       if(socketpair(AF_UNIX, SOCK_STREAM, 0, fd)) {
+           perror("Debug leaking scalars socketpair failed");
+           abort();
+       }
+
+       child = fork();
+       if(child == -1) {
+           perror("Debug leaking scalars fork failed");
+           abort();
+       }
+       if (!child) {
+           /* We are the child */
+           const int sock = fd[1];
+           const int debug_fd = PerlIO_fileno(Perl_debug_log);
+           int f;
+           const char *where;
+           /* Our success message is an integer 0, and a char 0  */
+           static const char success[sizeof(int) + 1];
+
+           close(fd[0]);
+
+           /* We need to close all other file descriptors otherwise we end up
+              with interesting hangs, where the parent closes its end of a
+              pipe, and sits waiting for (another) child to terminate. Only
+              that child never terminates, because it never gets EOF, because
+              we also have the far end of the pipe open.  We even need to
+              close the debugging fd, because sometimes it happens to be one
+              end of a pipe, and a process is waiting on the other end for
+              EOF. Normally it would be closed at some point earlier in
+              destruction, but if we happen to cause the pipe to remain open,
+              EOF never occurs, and we get an infinite hang. Hence all the
+              games to pass in a file descriptor if it's actually needed.  */
+
+           f = sysconf(_SC_OPEN_MAX);
+           if(f < 0) {
+               where = "sysconf failed";
+               goto abort;
+           }
+           while (f--) {
+               if (f == sock)
+                   continue;
+               close(f);
+           }
+
+           while (1) {
+               SV *target;
+               union control_un control;
+               struct msghdr msg;
+               struct iovec vec[1];
+               struct cmsghdr *cmptr;
+               ssize_t got;
+               int got_fd;
+
+               msg.msg_control = control.control;
+               msg.msg_controllen = sizeof(control.control);
+               /* We're a connected socket so we don't need a source  */
+               msg.msg_name = NULL;
+               msg.msg_namelen = 0;
+               msg.msg_iov = vec;
+               msg.msg_iovlen = sizeof(vec)/sizeof(vec[0]);
+
+               vec[0].iov_base = (void*)&target;
+               vec[0].iov_len = sizeof(target);
+      
+               got = recvmsg(sock, &msg, 0);
+
+               if(got == 0)
+                   break;
+               if(got < 0) {
+                   where = "recv failed";
+                   goto abort;
+               }
+               if(got < sizeof(target)) {
+                   where = "short recv";
+                   goto abort;
+               }
+
+               if(!(cmptr = CMSG_FIRSTHDR(&msg))) {
+                   where = "no cmsg";
+                   goto abort;
+               }
+               if(cmptr->cmsg_len != CMSG_LEN(sizeof(int))) {
+                   where = "wrong cmsg_len";
+                   goto abort;
+               }
+               if(cmptr->cmsg_level != SOL_SOCKET) {
+                   where = "wrong cmsg_level";
+                   goto abort;
+               }
+               if(cmptr->cmsg_type != SCM_RIGHTS) {
+                   where = "wrong cmsg_type";
+                   goto abort;
+               }
+
+               got_fd = *(int*)CMSG_DATA(cmptr);
+               /* For our last little bit of trickery, put the file descriptor
+                  back into Perl_debug_log, as if we never actually closed it
+               */
+               if(got_fd != debug_fd) {
+                   if (dup2(got_fd, debug_fd) == -1) {
+                       where = "dup2";
+                       goto abort;
+                   }
+               }
+               sv_dump(target);
+
+               PerlIO_flush(Perl_debug_log);
+
+               got = write(sock, &success, sizeof(success));
+
+               if(got < 0) {
+                   where = "write failed";
+                   goto abort;
+               }
+               if(got < sizeof(success)) {
+                   where = "short write";
+                   goto abort;
+               }
+           }
+           _exit(0);
+       abort:
+           {
+               int send_errno = errno;
+               unsigned char length = (unsigned char) strlen(where);
+               struct iovec failure[3] = {
+                   {(void*)&send_errno, sizeof(send_errno)},
+                   {&length, 1},
+                   {(void*)where, length}
+               };
+               int got = writev(sock, failure, 3);
+               /* Bad news travels fast. Faster than data. We'll get a SIGPIPE
+                  in the parent if we try to read from the socketpair after the
+                  child has exited, even if there was data to read.
+                  So sleep a bit to give the parent a fighting chance of
+                  reading the data.  */
+               sleep(2);
+               _exit((got == -1) ? errno : 0);
+           }
+           /* End of child.  */
+       }
+       PL_dumper_fd = fd[0];
+       close(fd[1]);
+    }
+#endif
+    
     /* We must account for everything.  */
 
     /* Destroy the main CV and syntax tree */
+    /* Do this now, because destroying ops can cause new SVs to be generated
+       in Perl_pad_swipe, and when running with -DDEBUG_LEAKING_SCALARS they
+       PL_curcop to point to a valid op from which the filename structure
+       member is copied.  */
+    PL_curcop = &PL_compiling;
     if (PL_main_root) {
        /* ensure comppad/curpad to refer to main's pad */
        if (CvPADLIST(PL_main_cv)) {
@@ -444,7 +719,6 @@ perl_destruct(pTHXx)
        op_free(PL_main_root);
        PL_main_root = Nullop;
     }
-    PL_curcop = &PL_compiling;
     PL_main_start = Nullop;
     SvREFCNT_dec(PL_main_cv);
     PL_main_cv = Nullcv;
@@ -803,23 +1077,23 @@ perl_destruct(pTHXx)
     {
        /* Yell and reset the HeVAL() slots that are still holding refcounts,
         * so that sv_free() won't fail on them.
+        * Now that the global string table is using a single hunk of memory
+        * for both HE and HEK, we either need to explicitly unshare it the
+        * correct way, or actually free things here.
         */
-       I32 riter;
-       I32 max;
-       HE *hent;
-       HE **array;
-
-       riter = 0;
-       max = HvMAX(PL_strtab);
-       array = HvARRAY(PL_strtab);
-       hent = array[0];
+       I32 riter = 0;
+       const I32 max = HvMAX(PL_strtab);
+       HE **array = HvARRAY(PL_strtab);
+       HE *hent = array[0];
+
        for (;;) {
            if (hent && ckWARN_d(WARN_INTERNAL)) {
+               HE *next = HeNEXT(hent);
                Perl_warner(aTHX_ packWARN(WARN_INTERNAL),
                     "Unbalanced string table refcount: (%d) for \"%s\"",
                     HeVAL(hent) - Nullsv, HeKEY(hent));
-               HeVAL(hent) = Nullsv;
-               hent = HeNEXT(hent);
+               Safefree(hent);
+               hent = next;
            }
            if (!hent) {
                if (++riter > max)
@@ -827,6 +1101,11 @@ perl_destruct(pTHXx)
                hent = array[riter];
            }
        }
+
+       Safefree(array);
+       HvARRAY(PL_strtab) = 0;
+       HvTOTALKEYS(PL_strtab) = 0;
+       HvFILL(PL_strtab) = 0;
     }
     SvREFCNT_dec(PL_strtab);
 
@@ -883,10 +1162,31 @@ perl_destruct(pTHXx)
                            PL_op_name[sv->sv_debug_optype]: "(none)",
                        sv->sv_debug_cloned ? " (cloned)" : ""
                    );
+#ifdef DEBUG_LEAKING_SCALARS_FORK_DUMP
+                   Perl_dump_sv_child(aTHX_ sv);
+#endif
                }
            }
        }
     }
+#ifdef DEBUG_LEAKING_SCALARS_FORK_DUMP
+    {
+       int status;
+       fd_set rset;
+       /* Wait for up to 4 seconds for child to terminate.
+          This seems to be the least effort way of timing out on reaping
+          its exit status.  */
+       struct timeval waitfor = {4, 0};
+       int sock = PL_dumper_fd;
+
+       shutdown(sock, 1);
+       FD_ZERO(&rset);
+       FD_SET(sock, &rset);
+       select(sock + 1, &rset, NULL, NULL, &waitfor);
+       waitpid(child, &status, WNOHANG);
+       close(sock);
+    }
+#endif
 #endif
     PL_sv_count = 0;
 
@@ -908,8 +1208,7 @@ perl_destruct(pTHXx)
     Safefree(PL_reg_start_tmp);
     PL_reg_start_tmp = (char**)NULL;
     PL_reg_start_tmpl = 0;
-    if (PL_reg_curpm)
-       Safefree(PL_reg_curpm);
+    Safefree(PL_reg_curpm);
     Safefree(PL_reg_poscache);
     free_tied_hv_pool();
     Safefree(PL_op_mask);
@@ -1067,9 +1366,9 @@ S_set_caret_X(pTHX) {
        S_procself_val(aTHX_ GvSV(tmpgv), PL_origargv[0]);
 #else
 #ifdef OS2
-       sv_setpv(GvSV(tmpgv), os2_execname(aTHX));
+       sv_setpv(GvSVn(tmpgv), os2_execname(aTHX));
 #else
-       sv_setpv(GvSV(tmpgv),PL_origargv[0]);
+       sv_setpv(GvSVn(tmpgv),PL_origargv[0]);
 #endif
 #endif
     }
@@ -1091,6 +1390,8 @@ perl_parse(pTHXx_ XSINIT_t xsinit, int argc, char **argv, char **env)
     int ret;
     dJMPENV;
 
+    PERL_UNUSED_VAR(my_perl);
+
 #ifdef SETUID_SCRIPTS_ARE_SECURE_NOW
 #ifdef IAMSUID
 #undef IAMSUID
@@ -1108,15 +1409,10 @@ setuid perl scripts securely.\n");
     if (!PL_rehash_seed_set)
         PL_rehash_seed = get_hash_seed();
     {
-        char *s = PerlEnv_getenv("PERL_HASH_SEED_DEBUG");
-
-        if (s) {
-             int i = atoi(s);
+       const char * const s = PerlEnv_getenv("PERL_HASH_SEED_DEBUG");
 
-             if (i == 1)
-                  PerlIO_printf(Perl_debug_log, "HASH_SEED = %"UVuf"\n",
-                                PL_rehash_seed);
-        }
+       if (s && (atoi(s) == 1))
+           PerlIO_printf(Perl_debug_log, "HASH_SEED = %"UVuf"\n", PL_rehash_seed);
     }
 #endif /* #if defined(USE_HASH_SEED) || defined(USE_HASH_SEED_EXPLICIT) */
 
@@ -1133,10 +1429,10 @@ setuid perl scripts securely.\n");
         * --jhi */
         const char *s = NULL;
         int i;
-        UV mask =
+        const UV mask =
           ~(UV)(PTRSIZE == 4 ? 3 : PTRSIZE == 8 ? 7 : PTRSIZE == 16 ? 15 : 0);
          /* Do the mask check only if the args seem like aligned. */
-        UV aligned =
+        const UV aligned =
           (mask < ~(UV)0) && ((PTR2UV(argv[0]) & mask) == PTR2UV(argv[0]));
 
         /* See if all the arguments are contiguous in memory.  Note
@@ -1412,117 +1708,130 @@ S_parse_body(pTHX_ char **env, XSINIT_t xsinit)
            s++;
            goto reswitch;
        case 'V':
-           if (!PL_preambleav)
-               PL_preambleav = newAV();
-           av_push(PL_preambleav, newSVpv("use Config qw(myconfig config_vars)",0));
-           if (*++s != ':')  {
-                STRLEN opts;
-
-               PL_Sv = newSVpv("print myconfig();",0);
+           {
+               SV *opts_prog;
+
+               if (!PL_preambleav)
+                   PL_preambleav = newAV();
+               av_push(PL_preambleav,
+                       newSVpv("use Config;",0));
+               if (*++s != ':')  {
+                   STRLEN opts;
+               
+                   opts_prog = newSVpv("print Config::myconfig(),",0);
 #ifdef VMS
-               sv_catpv(PL_Sv,"print \"\\nCharacteristics of this PERLSHR image: \\n\",");
+                   sv_catpv(opts_prog,"\"\\nCharacteristics of this PERLSHR image: \\n\",");
 #else
-               sv_catpv(PL_Sv,"print \"\\nCharacteristics of this binary (from libperl): \\n\",");
+                   sv_catpv(opts_prog,"\"\\nCharacteristics of this binary (from libperl): \\n\",");
 #endif
-                opts = SvCUR(PL_Sv);
+                   opts = SvCUR(opts_prog);
 
-               sv_catpv(PL_Sv,"\"  Compile-time options:");
+                   sv_catpv(opts_prog,"\"  Compile-time options:");
 #  ifdef DEBUGGING
-               sv_catpv(PL_Sv," DEBUGGING");
+                   sv_catpv(opts_prog," DEBUGGING");
 #  endif
 #  ifdef MULTIPLICITY
-               sv_catpv(PL_Sv," MULTIPLICITY");
+                   sv_catpv(opts_prog," MULTIPLICITY");
 #  endif
 #  ifdef USE_5005THREADS
-               sv_catpv(PL_Sv," USE_5005THREADS");
+                   sv_catpv(opts_prog," USE_5005THREADS");
 #  endif
 #  ifdef USE_ITHREADS
-               sv_catpv(PL_Sv," USE_ITHREADS");
+                   sv_catpv(opts_prog," USE_ITHREADS");
 #  endif
 #  ifdef USE_64_BIT_INT
-               sv_catpv(PL_Sv," USE_64_BIT_INT");
+                   sv_catpv(opts_prog," USE_64_BIT_INT");
 #  endif
 #  ifdef USE_64_BIT_ALL
-               sv_catpv(PL_Sv," USE_64_BIT_ALL");
+                   sv_catpv(opts_prog," USE_64_BIT_ALL");
 #  endif
 #  ifdef USE_LONG_DOUBLE
-               sv_catpv(PL_Sv," USE_LONG_DOUBLE");
+                   sv_catpv(opts_prog," USE_LONG_DOUBLE");
 #  endif
 #  ifdef USE_LARGE_FILES
-               sv_catpv(PL_Sv," USE_LARGE_FILES");
+                   sv_catpv(opts_prog," USE_LARGE_FILES");
 #  endif
 #  ifdef USE_SOCKS
-               sv_catpv(PL_Sv," USE_SOCKS");
+                   sv_catpv(opts_prog," USE_SOCKS");
 #  endif
 #  ifdef USE_SITECUSTOMIZE
-               sv_catpv(PL_Sv," USE_SITECUSTOMIZE");
+                   sv_catpv(opts_prog," USE_SITECUSTOMIZE");
 #  endif              
 #  ifdef PERL_IMPLICIT_CONTEXT
-               sv_catpv(PL_Sv," PERL_IMPLICIT_CONTEXT");
+                   sv_catpv(opts_prog," PERL_IMPLICIT_CONTEXT");
 #  endif
 #  ifdef PERL_IMPLICIT_SYS
-               sv_catpv(PL_Sv," PERL_IMPLICIT_SYS");
+                   sv_catpv(opts_prog," PERL_IMPLICIT_SYS");
 #  endif
 
-                while (SvCUR(PL_Sv) > opts+76) {
-                    /* find last space after "options: " and before col 76 */
+                   while (SvCUR(opts_prog) > opts+76) {
+                       /* find last space after "options: " and before col 76
+                        */
 
-                    const char *space;
-                    char *pv = SvPV_nolen(PL_Sv);
-                    const char c = pv[opts+76];
-                    pv[opts+76] = '\0';
-                    space = strrchr(pv+opts+26, ' ');
-                    pv[opts+76] = c;
-                    if (!space) break; /* "Can't happen" */
+                       const char *space;
+                       char *pv = SvPV_nolen(opts_prog);
+                       const char c = pv[opts+76];
+                       pv[opts+76] = '\0';
+                       space = strrchr(pv+opts+26, ' ');
+                       pv[opts+76] = c;
+                       if (!space) break; /* "Can't happen" */
 
-                    /* break the line before that space */
+                       /* break the line before that space */
 
-                    opts = space - pv;
-                    sv_insert(PL_Sv, opts, 0,
-                              "\\n                       ", 25);
-                }
+                       opts = space - pv;
+                       sv_insert(opts_prog, opts, 0,
+                                 "\\n                       ", 25);
+                   }
 
-               sv_catpv(PL_Sv,"\\n\",");
+                   sv_catpv(opts_prog,"\\n\",");
 
 #if defined(LOCAL_PATCH_COUNT)
-               if (LOCAL_PATCH_COUNT > 0) {
-                   int i;
-                   sv_catpv(PL_Sv,"\"  Locally applied patches:\\n\",");
-                   for (i = 1; i <= LOCAL_PATCH_COUNT; i++) {
-                       if (PL_localpatches[i])
-                           Perl_sv_catpvf(aTHX_ PL_Sv,"q%c\t%s\n%c,",
-                                   0, PL_localpatches[i], 0);
+                   if (LOCAL_PATCH_COUNT > 0) {
+                       int i;
+                       sv_catpv(opts_prog,
+                                "\"  Locally applied patches:\\n\",");
+                       for (i = 1; i <= LOCAL_PATCH_COUNT; i++) {
+                           if (PL_localpatches[i])
+                               Perl_sv_catpvf(aTHX_ opts_prog,"q%c\t%s\n%c,",
+                                              0, PL_localpatches[i], 0);
+                       }
                    }
-               }
 #endif
-               Perl_sv_catpvf(aTHX_ PL_Sv,"\"  Built under %s\\n\"",OSNAME);
+                   Perl_sv_catpvf(aTHX_ opts_prog,
+                                  "\"  Built under %s\\n\"",OSNAME);
 #ifdef __DATE__
 #  ifdef __TIME__
-               Perl_sv_catpvf(aTHX_ PL_Sv,",\"  Compiled at %s %s\\n\"",__DATE__,__TIME__);
+                   Perl_sv_catpvf(aTHX_ opts_prog,
+                                  ",\"  Compiled at %s %s\\n\"",__DATE__,
+                                  __TIME__);
 #  else
-               Perl_sv_catpvf(aTHX_ PL_Sv,",\"  Compiled on %s\\n\"",__DATE__);
+                   Perl_sv_catpvf(aTHX_ opts_prog,",\"  Compiled on %s\\n\"",
+                                  __DATE__);
 #  endif
 #endif
-               sv_catpv(PL_Sv, "; \
-$\"=\"\\n    \"; \
-@env = map { \"$_=\\\"$ENV{$_}\\\"\" } sort grep {/^PERL/} keys %ENV; ");
+                   sv_catpv(opts_prog, "; $\"=\"\\n    \"; "
+                            "@env = map { \"$_=\\\"$ENV{$_}\\\"\" } "
+                            "sort grep {/^PERL/} keys %ENV; ");
 #ifdef __CYGWIN__
-               sv_catpv(PL_Sv,"\
-push @env, \"CYGWIN=\\\"$ENV{CYGWIN}\\\"\";");
+                   sv_catpv(opts_prog,
+                            "push @env, \"CYGWIN=\\\"$ENV{CYGWIN}\\\"\";");
 #endif
-               sv_catpv(PL_Sv, "\
-print \"  \\%ENV:\\n    @env\\n\" if @env; \
-print \"  \\@INC:\\n    @INC\\n\";");
-           }
-           else {
-               PL_Sv = newSVpv("config_vars(qw(",0);
-               sv_catpv(PL_Sv, ++s);
-               sv_catpv(PL_Sv, "))");
-               s += strlen(s);
+                   sv_catpv(opts_prog, 
+                            "print \"  \\%ENV:\\n    @env\\n\" if @env;"
+                            "print \"  \\@INC:\\n    @INC\\n\";");
+               }
+               else {
+                   ++s;
+                   opts_prog = Perl_newSVpvf(aTHX_
+                                             "Config::config_vars(qw%c%s%c)",
+                                             0, s, 0);
+                   s += strlen(s);
+               }
+               av_push(PL_preambleav, opts_prog);
+               /* don't look for script or read stdin */
+               scriptname = BIT_BUCKET;
+               goto reswitch;
            }
-           av_push(PL_preambleav, PL_Sv);
-           scriptname = BIT_BUCKET;    /* don't look for script or read stdin */
-           goto reswitch;
        case 'x':
            PL_doextract = TRUE;
            s++;
@@ -1834,6 +2143,8 @@ perl_run(pTHXx)
     int ret = 0;
     dJMPENV;
 
+    PERL_UNUSED_ARG(my_perl);
+
     oldscope = PL_scopestack_ix;
 #ifdef VMS
     VMSISH_HUSHED = 0;
@@ -2233,6 +2544,9 @@ Perl_call_sv(pTHX_ SV *sv, I32 flags)
            POPEVAL(cx);
            PL_curpm = newpm;
            LEAVE;
+           PERL_UNUSED_VAR(newsp);
+           PERL_UNUSED_VAR(gimme);
+           PERL_UNUSED_VAR(optype);
        }
        JMPENV_POP;
     }
@@ -2404,11 +2718,8 @@ Perl_require_pv(pTHX_ const char *pv)
     dSP;
     PUSHSTACKi(PERLSI_REQUIRE);
     PUTBACK;
-    sv = sv_newmortal();
-    sv_setpv(sv, "require '");
-    sv_catpv(sv, pv);
-    sv_catpv(sv, "'");
-    eval_sv(sv, G_DISCARD);
+    sv = Perl_newSVpvf(aTHX_ "require q%c%s%c", 0, pv, 0);
+    eval_sv(sv_2mortal(sv), G_DISCARD);
     SPAGAIN;
     POPSTACK;
 }
@@ -2628,12 +2939,10 @@ Perl_moreswitches(pTHX_ char *s)
                sv_catpv(sv, start);
            else {
                sv_catpvn(sv, start, s-start);
-               sv_catpv(sv, " split(/,/,q{");
-               sv_catpv(sv, ++s);
-               sv_catpv(sv, "})");
+               Perl_sv_catpvf(aTHX_ sv, " split(/,/,q%c%s%c)", 0, ++s, 0);
            }
            s += strlen(s);
-           my_setenv("PERL5DB", SvPV(sv, PL_na));
+           my_setenv("PERL5DB", SvPV_nolen_const(sv));
        }
        if (!PL_perldb) {
            PL_perldb = PERLDB_ALL;
@@ -2658,8 +2967,7 @@ Perl_moreswitches(pTHX_ char *s)
        usage(PL_origargv[0]);
        my_exit(0);
     case 'i':
-       if (PL_inplace)
-           Safefree(PL_inplace);
+       Safefree(PL_inplace);
 #if defined(__CYGWIN__) /* do backup extension automagically */
        if (*(s+1) == '\0') {
        PL_inplace = savepv(".bak");
@@ -2738,9 +3046,7 @@ Perl_moreswitches(pTHX_ char *s)
                sv_catpvn(sv, start, s-start);
            }
            if (*s == '=') {
-               sv_catpvn(sv, " split(/,/,q\0", 13);
-               sv_catpv(sv, s+1);
-               sv_catpvn(sv, "\0)", 2);
+               Perl_sv_catpvf(aTHX_ sv, " split(/,/,q%c%s%c)", 0, ++s, 0);
                s+=strlen(s);
            }
            else if (*s != '\0') {
@@ -2759,8 +3065,10 @@ Perl_moreswitches(pTHX_ char *s)
            SV *sv;
            const char *use = "use ";
            /* -M-foo == 'no foo'       */
-           if (*s == '-') { use = "no "; ++s; }
-           sv = newSVpv(use,0);
+           /* Leading space on " no " is deliberate, to make both
+              possibilities the same length.  */
+           if (*s == '-') { use = " no "; ++s; }
+           sv = newSVpvn(use,4);
            start = s;
            /* We allow -M'Module qw(Foo Bar)'  */
            while(isALNUM(*s) || *s==':') ++s;
@@ -2828,13 +3136,13 @@ Perl_moreswitches(pTHX_ char *s)
                (void *)upg_version(PL_patchlevel);
 #if !defined(DGUX)
        PerlIO_printf(PerlIO_stdout(),
-               Perl_form(aTHX_ "\nThis is perl, v%"SVf" built for %s",
+               Perl_form(aTHX_ "\nThis is perl, %"SVf" built for %s",
                    vstringify(PL_patchlevel),
                    ARCHNAME));
 #else /* DGUX */
 /* Adjust verbose output as in the perl that ships with the DG/UX OS from EMC */
        PerlIO_printf(PerlIO_stdout(),
-               Perl_form(aTHX_ "\nThis is perl, v%"SVf"\n",
+               Perl_form(aTHX_ "\nThis is perl, %"SVf"\n",
                    vstringify(PL_patchlevel)));
        PerlIO_printf(PerlIO_stdout(),
                        Perl_form(aTHX_ "        built under %s at %s %s\n",
@@ -3075,6 +3383,9 @@ S_init_main_stash(pTHX)
     PL_replgv = gv_fetchpv("\022", TRUE, SVt_PV); /* ^R */
     GvMULTI_on(PL_replgv);
     (void)Perl_form(aTHX_ "%240s",""); /* Preallocate temp - for immediate signals. */
+#ifdef PERL_DONT_CREATE_GVSV
+    gv_SVadd(PL_errgv);
+#endif
     sv_grow(ERRSV, 240);       /* Preallocate - for immediate signals. */
     sv_setpvn(ERRSV, "", 0);
     PL_curstash = PL_defstash;
@@ -4092,8 +4403,7 @@ S_init_predump_symbols(pTHX)
 
     PL_statname = NEWSV(66,0);         /* last filename we did stat on */
 
-    if (PL_osname)
-       Safefree(PL_osname);
+    Safefree(PL_osname);
     PL_osname = savepv(OSNAME);
 }
 
@@ -4841,17 +5151,19 @@ S_my_exit_jump(pTHX)
     }
 
     JMPENV_JUMP(2);
+    PERL_UNUSED_VAR(gimme);
+    PERL_UNUSED_VAR(newsp);
 }
 
 static I32
 read_e_script(pTHX_ int idx, SV *buf_sv, int maxlen)
 {
-    const char *p, *nl;
-    (void)idx;
-    (void)maxlen;
+    const char * const p  = SvPVX_const(PL_e_script);
+    const char *nl = strchr(p, '\n');
+
+    PERL_UNUSED_ARG(idx);
+    PERL_UNUSED_ARG(maxlen);
 
-    p  = SvPVX_const(PL_e_script);
-    nl = strchr(p, '\n');
     nl = (nl) ? nl+1 : SvEND(PL_e_script);
     if (nl-p == 0) {
        filter_del(read_e_script);