[MERGE] fix -DPERL_GLOBAL_STRUCT_PRIVATE builds

With no automatic smoking, this build option has suffered some bitrot over
the last few months.

7 files changed, 23 insertions, 12 deletions

diff --git a/dump.c b/dump.c
index c5e3a79feb..7cdebfe875 100644
--- a/dump.c
+++ b/dump.c
@@ -930,7 +930,7 @@ const struct flag_to_name op_flags_names[] = {
 
 
 /* indexed by enum OPclass */
-const char * op_class_names[] = {
+const char * const op_class_names[] = {
     "NULL",
     "OP",
     "UNOP",
diff --git a/globvar.sym b/globvar.sym
index 2943fc6691..c82dc8f1c8 100644
--- a/globvar.sym
+++ b/globvar.sym
@@ -19,6 +19,7 @@ PL_hexdigit
 PL_inf
 PL_interp_size
 PL_interp_size_5_18_0
+PL_isa_DOES
 PL_keyword_plugin
 PL_latin1_lc
 PL_magic_data
diff --git a/perl.h b/perl.h
index 867c30050d..70e12bd722 100644
--- a/perl.h
+++ b/perl.h
@@ -4799,6 +4799,12 @@ EXTCONST U8 PL_subversion
 EXTCONST char PL_uuemap[65]
   INIT("`!\"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_");
 
+/* a special string address whose value is "isa", but which perl knows
+ * to treat as if it were really "DOES" when printing the method name in
+ *  the "Can't call method '%s'" error message */
+EXTCONST char PL_isa_DOES[]
+  INIT("isa");
+
 #ifdef DOINIT
 EXTCONST char PL_uudmap[256] =
 #  ifdef PERL_MICRO
diff --git a/pp_hot.c b/pp_hot.c
index 4f0d094ce6..7c98c90337 100644
--- a/pp_hot.c
+++ b/pp_hot.c
@@ -4391,8 +4391,6 @@ Perl_vivify_ref(pTHX_ SV *sv, U32 to_what)
     return sv;
 }
 
-extern char PL_isa_DOES[];
-
 PERL_STATIC_INLINE HV *
 S_opmethod_stash(pTHX_ SV* meth)
 {
diff --git a/scope.c b/scope.c
index c51a125dfa..a7c17e8d9e 100644
--- a/scope.c
+++ b/scope.c
@@ -788,7 +788,7 @@ Perl_save_alloc(pTHX_ I32 size, I32 pad)
 }
 
 
-static U8 arg_counts[] = {
+static const U8 arg_counts[] = {
     0, /* SAVEt_ALLOC              */
     0, /* SAVEt_CLEARPADRANGE      */
     0, /* SAVEt_CLEARSV            */
diff --git a/t/porting/libperl.t b/t/porting/libperl.t
index 8c1350f68c..1536fda944 100644
--- a/t/porting/libperl.t
+++ b/t/porting/libperl.t
@@ -359,8 +359,19 @@ if ($GSP) {
     ok(! exists $symbols{data}{data} ||
             # clang with ASAN seems to add this symbol to every object file:
             !grep($_ ne '__unnamed_1', keys %{$symbols{data}{data}}),
-        "has no data data symbols");
-    ok(! exists $symbols{data}{common}, "has no data common symbols");
+        "has no data data symbols")
+        or do {
+            my $bad = "DATA entries (there are supposed to be none):\n";
+            $bad .= "  data sym: $_\n" for sort keys %{$symbols{data}{data}};
+            diag($bad);
+        };
+
+    ok(! exists $symbols{data}{common}, "has no data common symbols")
+        or do {
+            my $bad = "COMMON entries (there are supposed to be none):\n";
+            $bad .= "  common sym: $_\n" for sort keys %{$symbols{data}{common}};
+            diag($bad);
+        };
 
     # -DPERL_GLOBAL_STRUCT_PRIVATE should NOT have
     # the extra text symbol for accessing the vars
diff --git a/universal.c b/universal.c
index 88835f9d78..be39310da7 100644
--- a/universal.c
+++ b/universal.c
@@ -184,11 +184,6 @@ The SV can be a Perl object or the name of a Perl class.
 
 #include "XSUB.h"
 
-/* a special string address whose value is "isa", but which perl knows
- * to treat as if it were really "DOES" when printing the method name in
- *  the "Can't call method '%s'" error message */
-char PL_isa_DOES[] = "isa";
-
 bool
 Perl_sv_does_sv(pTHX_ SV *sv, SV *namesv, U32 flags)
 {
@@ -232,7 +227,7 @@ Perl_sv_does_sv(pTHX_ SV *sv, SV *namesv, U32 flags)
     methodname = newSV_type(SVt_PV);
     SvLEN(methodname) = 0;
     SvCUR(methodname) = strlen(PL_isa_DOES);
-    SvPVX(methodname) = PL_isa_DOES;
+    SvPVX(methodname) = (char *)PL_isa_DOES; /* discard 'const' qualifier */
     SvPOK_on(methodname);
     sv_2mortal(methodname);
     call_sv(methodname, G_SCALAR | G_METHOD);