Finally! Worked out how to const Perl_moreswitches().

Although I've committed crimes against indenting to avoid losing
blame annotation history. Revisit this when we have version control
that can easily see through whitespace changes.
[Can probably now propagate consting inside S_parse_body(),
Perl_moreswitches() and Perl_yylex(), but that will not affect the
external API, so can wait until after 5.10]

p4raw-id: //depot/perl@32057

1 files changed, 24 insertions, 6 deletions

diff --git a/perl.c b/perl.c
index 158526ab29..8b29386c3d 100644
--- a/perl.c
+++ b/perl.c
@@ -1686,7 +1686,7 @@ S_parse_body(pTHX_ char **env, XSINIT_t xsinit)
     VOL bool dosearch = FALSE;
     const char *validarg = "";
     register SV *sv;
-    register char *s, c;
+    register char c;
     const char *cddir = NULL;
 #ifdef USE_SITECUSTOMIZE
     bool minus_f = FALSE;
@@ -1701,6 +1701,8 @@ S_parse_body(pTHX_ char **env, XSINIT_t xsinit)
     SAVEFREESV(sv);
     init_main_stash();
 
+    {
+	const char *s;
     for (argc--,argv++; argc > 0; argc--,argv++) {
 	if (argv[0][0] != '-' || !argv[0][1])
 	    break;
@@ -1953,8 +1955,13 @@ S_parse_body(pTHX_ char **env, XSINIT_t xsinit)
 	    Perl_croak(aTHX_ "Unrecognized switch: -%s  (-h will show valid options)",s);
 	}
     }
+    }
+
   switch_end:
 
+    {
+	char *s;
+
     if (
 #ifndef SECURE_INTERNAL_GETENV
         !PL_tainting &&
@@ -2007,6 +2014,7 @@ S_parse_body(pTHX_ char **env, XSINIT_t xsinit)
 	    }
 	}
     }
+    }
 
 #ifdef USE_SITECUSTOMIZE
     if (!minus_f) {
@@ -2159,6 +2167,8 @@ S_parse_body(pTHX_ char **env, XSINIT_t xsinit)
 	 }
     }
 
+    {
+	const char *s;
     if ((s = PerlEnv_getenv("PERL_SIGNALS"))) {
 	 if (strEQ(s, "unsafe"))
 	      PL_signals |=  PERL_SIGNALS_UNSAFE_FLAG;
@@ -2167,8 +2177,11 @@ S_parse_body(pTHX_ char **env, XSINIT_t xsinit)
 	 else
 	      Perl_croak(aTHX_ "PERL_SIGNALS illegal: \"%s\"", s);
     }
+    }
 
 #ifdef PERL_MAD
+    {
+	const char *s;
     if ((s = PerlEnv_getenv("PERL_XMLDUMP"))) {
 	PL_madskills = 1;
 	PL_minus_c = 1;
@@ -2181,10 +2194,15 @@ S_parse_body(pTHX_ char **env, XSINIT_t xsinit)
 	}
 	my_setenv("PERL_XMLDUMP", NULL);	/* hide from subprocs */
     }
+    }
+
+    {
+	const char *s;
     if ((s = PerlEnv_getenv("PERL_MADSKILLS"))) {
 	PL_madskills = atoi(s);
 	my_setenv("PERL_MADSKILLS", NULL);	/* hide from subprocs */
     }
+    }
 #endif
 
     lex_start(linestr_sv, rsfp, TRUE);
@@ -2944,8 +2962,8 @@ Perl_get_debug_opts(pTHX_ const char **s, bool givehelp)
 
 /* This routine handles any switches that can be given during run */
 
-char *
-Perl_moreswitches(pTHX_ char *s)
+const char *
+Perl_moreswitches(pTHX_ const char *s)
 {
     dVAR;
     UV rschar;
@@ -3092,7 +3110,7 @@ Perl_moreswitches(pTHX_ char *s)
 	while (*s && isSPACE(*s))
 	    ++s;
 	if (*s) {
-	    char *e, *p;
+	    const char *e, *p;
 	    p = s;
 	    /* ignore trailing spaces (possibly followed by other switches) */
 	    do {
@@ -3141,7 +3159,7 @@ Perl_moreswitches(pTHX_ char *s)
     case 'm':
 	forbid_setid('m', -1);	/* XXX ? */
 	if (*++s) {
-	    char *start;
+	    const char *start;
 	    SV *sv;
 	    const char *use = "use ";
 	    /* -M-foo == 'no foo'	*/
@@ -4251,7 +4269,7 @@ STATIC void
 S_find_beginning(pTHX_ SV* linestr_sv, PerlIO *rsfp)
 {
     dVAR;
-    register char *s;
+    const char *s;
     register const char *s2;
 #ifdef MACOS_TRADITIONAL
     int maclines = 0;