classes/*.c is created by the bytecode compiler classes/pmc2c2.pl. Most
of the actual code is in lib/Parrot/Pmc2c.pm.

The created C code could need some improvements:

* the temp_base_vtable should be const.
   This is currently not possible, because items like ".whoami" are
changed in the temp_base_vtable. But we don't have to do that, as the
vtable is cloned a few lines below anyway. So we should create a const
table and do the rest of the init stuff in the cloned table.

* same with the MMD init table.

* All constant strings in classes (whoami, isa_str, does_str) and method
names in the delegate.c should use the CONST_STRING() macro. That would
need some Makefile tweaks too, to add a dependency on the .str file.
Note: foo = CONST_STRING(interpreter, "foo"); should always be on it's
own line and not inside a multiline expression.

Thanks,
leo

Can I add a fourth - one I said to Dan I intended to do, but so far haven't
managed:

* The created C code could benefit from #line directives to track where
  C code came from the input .pmc file, so that compiler errors are reported
  for the original .pmc file. Perl 5's xsubpp does this well, using #line
  directives to switch between foo.c and foo.xs, depending on whether that
  section of code was human written, or autogenerated. It makes things much
  easier while developing.

Of course, I may find time to do this before anyone else does, but anyone
is welcome to beat me to it.

Nicholas Clark

Yep, thanks. The hooks are there, as well as a command-line option to
turn line numbers off, which is sometimes useful.

Anyway most line number stuff is already inside, but it's broken and
needs fixing.

:)

leo

On Oct 30, 2004, at 12:58 AM, Leopold Toetsch wrote:

FYI I'm fiddling with classes/pmc2c2.pl, in connection with your
ccache-ish "feature request", but I'm not (much) touching Pmc2c.pm, so
I shouldn't conflict with anyone working there.

JEff

Patch attached.

Note: previously base_type for dynclasses was set twice in dynclasses.
I'm not clear why this was done.  If this is important, this will need
to be restored; but without it dynclasses/dynfoo.pasm passes anyway.

- Sam Ruby

[ const_base_vtable_and_mmd_init.patch 6K ]
Index: config/gen/makefiles/root.in
===================================================================
RCS file: /cvs/public/parrot/config/gen/makefiles/root.in,v
retrieving revision 1.254
diff -u -r1.254 root.in
--- config/gen/makefiles/root.in        12 Oct 2004 09:00:16 -0000      1.254
+++ config/gen/makefiles/root.in        1 Nov 2004 03:14:25 -0000
@@ -279,6 +279,8 @@

 CLASS_O_FILES = ${TEMP_pmc_classes_o}

+CLASS_STR_FILES = ${TEMP_pmc_classes_str}
+
 ENCODING_O_FILES = \
     encodings/utf8$(O)

@@ -478,7 +480,7 @@
     $(SRC)/pmc.str \
     $(SRC)/py_func.str \
     $(SRC)/objects.str \
-    classes/delegate.str
+    $(CLASS_STR_FILES)

 $(INC)/string_private_cstring.h : $(STR_FILES) build_tools/c2str.pl
        $(PERL) build_tools/c2str.pl --all
Index: config/inter/pmc.pl
===================================================================
RCS file: /cvs/public/parrot/config/inter/pmc.pl,v
retrieving revision 1.17
diff -u -r1.17 pmc.pl
--- config/inter/pmc.pl 9 May 2004 14:58:09 -0000       1.17
+++ config/inter/pmc.pl 1 Nov 2004 03:14:25 -0000
@@ -114,6 +114,7 @@

   # names of class files for classes/Makefile
   (my $TEMP_pmc_o = $pmc_list) =~ s/\.pmc/\$(O)/g;
+  (my $TEMP_pmc_str = $pmc_list) =~ s/\.pmc/\.str/g;

   # calls to pmc2c.pl for classes/Makefile
   my $TEMP_pmc_build = <<"E_NOTE";
@@ -145,7 +146,7 @@
 classes/pmc_$pmc.h: classes/$pmc.pmc
        \$(PMC2CC) classes/$pmc.pmc

-classes/$pmc\$(O): \$(NONGEN_HEADERS) \\
+classes/$pmc\$(O): classes/$pmc.str \$(NONGEN_HEADERS) \\
         $parent_headers

 END
@@ -155,6 +156,7 @@
   # build list of libraries for link line in Makefile
   my $slash = Configure::Data->get('slash');
   (my $TEMP_pmc_classes_o   = $TEMP_pmc_o   ) =~ s/^| / classes${slash}/g;
+  (my $TEMP_pmc_classes_str = $TEMP_pmc_str ) =~ s/^| / classes${slash}/g;
   (my $TEMP_pmc_classes_pmc = $pmc_list) =~ s/^| / classes${slash}/g;

   # Gather the actual names (with MixedCase) of all of the
@@ -191,6 +193,7 @@
     TEMP_pmc_o           => $TEMP_pmc_o,
     TEMP_pmc_build       => $TEMP_pmc_build,
     TEMP_pmc_classes_o   => $TEMP_pmc_classes_o,
+    TEMP_pmc_classes_str => $TEMP_pmc_classes_str,
     TEMP_pmc_classes_pmc => $TEMP_pmc_classes_pmc,
   );
 }
Index: include/parrot/vtables.h
===================================================================
RCS file: /cvs/public/parrot/include/parrot/vtables.h,v
retrieving revision 1.5
diff -u -r1.5 vtables.h
--- include/parrot/vtables.h    22 Apr 2004 08:55:06 -0000      1.5
+++ include/parrot/vtables.h    1 Nov 2004 03:14:26 -0000
@@ -14,7 +14,7 @@
 #define PARROT_VTABLES_H_GUARD

 VTABLE *Parrot_new_vtable(Parrot_Interp);
-VTABLE *Parrot_clone_vtable(Parrot_Interp, VTABLE *base_vtable);
+VTABLE *Parrot_clone_vtable(Parrot_Interp, const VTABLE *base_vtable);
 void Parrot_destroy_vtable(Parrot_Interp, VTABLE *vtable);

 void Parrot_vtable_set_type(Parrot_Interp, VTABLE *, INTVAL);
Index: lib/Parrot/Pmc2c.pm
===================================================================
RCS file: /cvs/public/parrot/lib/Parrot/Pmc2c.pm,v
retrieving revision 1.47
diff -u -r1.47 Pmc2c.pm
--- lib/Parrot/Pmc2c.pm 28 Oct 2004 11:24:37 -0000      1.47
+++ lib/Parrot/Pmc2c.pm 1 Nov 2004 03:14:26 -0000
@@ -378,6 +378,12 @@
 #include "pmc_$name.h"
 EOC
     }
+    if (!$self->{flags}{dynpmc}) {
+           my $name = lc $self->{class};
+           $cout .= <<"EOC";
+#include "$name.str"
+EOC
+    }
     "$cout\n";
 }

@@ -714,7 +720,7 @@
 void
 Parrot_${classname}_class_init(Parrot_Interp interp, int entry, int pass)
 {
-    struct _vtable temp_base_vtable = {
+    const struct _vtable temp_base_vtable = {
         NULL,  /* package */
         $enum_name,    /* base_type */
         NULL,  /* whoami */
@@ -728,7 +734,7 @@

     $cout .= <<"EOC";

-    MMD_init _temp_mmd_init[] = {
+    const MMD_init _temp_mmd_init[] = {
         $mmd_list
     };
     /*  Dynamic classes need the runtime type
@@ -742,13 +748,6 @@
     int my_enum_class_$dynclass = Parrot_PMC_typenum(interp, "$dynclass");
 EOC
     }
-    # init vtable slot
-    if ($self->{flags}{dynpmc}) {
-        $cout .= <<"EOC";
-
-    temp_base_vtable.base_type = entry;
-EOC
-    }
     # init MMD "right" slots with the dynpmc types
     foreach my $entry (@init_mmds) {
         if ($entry->[1] eq $classname) {
@@ -772,29 +771,39 @@
     $cout .= <<"EOC";
     if (pass == 0) {
 EOC
-    # init vtable slot
-    if ($self->{flags}{dynpmc}) {
-        $cout .= <<"EOC";
-        temp_base_vtable.base_type = entry;
-EOC
-    }
     $cout .= <<"EOC";
         /*
          * Parrot_base_vtables is a true global - register just once
          */
         if (!Parrot_base_vtables[entry]) {
-            temp_base_vtable.whoami = string_make(interp,
+            struct _vtable *clone =
+                Parrot_clone_vtable(interp, &temp_base_vtable);
+
+EOC
+    # init vtable slot
+    if ($self->{flags}{dynpmc}) {
+        $cout .= <<"EOC";
+            clone->base_type = entry;
+            clone->whoami = string_make(interp,
                 "$classname", @{[length($classname)]}, "iso-8859-1",
                 PObj_constant_FLAG|PObj_external_FLAG);
-            temp_base_vtable.isa_str = string_make(interp,
+            clone->isa_str = string_make(interp,
                 "$isa", @{[length($isa)]}, "iso-8859-1",
                 PObj_constant_FLAG|PObj_external_FLAG);
-            temp_base_vtable.does_str = string_make(interp,
+            clone->does_str = string_make(interp,
                 "$does", @{[length($does)]}, "iso-8859-1",
                 PObj_constant_FLAG|PObj_external_FLAG);
-
-            Parrot_base_vtables[entry] =
-                Parrot_clone_vtable(interp, &temp_base_vtable);
+EOC
+    }
+    else {
+        $cout .= <<"EOC";
+            clone->whoami = CONST_STRING(interp, "$classname");
+            clone->isa_str = CONST_STRING(interp, "$isa");
+            clone->does_str = CONST_STRING(interp, "$does");
+EOC
+    }
+    $cout .= <<"EOC";
+            Parrot_base_vtables[entry] = clone;
         }
 EOC
     $cout .= <<"EOC";
Index: src/vtables.c
===================================================================
RCS file: /cvs/public/parrot/src/vtables.c,v
retrieving revision 1.6
diff -u -r1.6 vtables.c
--- src/vtables.c       28 Jan 2004 23:55:24 -0000      1.6
+++ src/vtables.c       1 Nov 2004 03:14:26 -0000
@@ -37,7 +37,7 @@
 /*

 =item C<VTABLE *
-Parrot_clone_vtable(Parrot_Interp interpreter, VTABLE *base_vtable)>
+Parrot_clone_vtable(Parrot_Interp interpreter, const VTABLE *base_vtable)>

 Clones C<*base_vtable> and returns a pointer to the new C<VTABLE>.

@@ -46,7 +46,7 @@
 */

 VTABLE *
-Parrot_clone_vtable(Parrot_Interp interpreter, VTABLE *base_vtable) {
+Parrot_clone_vtable(Parrot_Interp interpreter, const VTABLE *base_vtable) {
     VTABLE *new_vtable = mem_sys_allocate(sizeof(VTABLE));
     if (new_vtable) {
         memcpy(new_vtable, base_vtable, sizeof(VTABLE));

Thanks, applied - with s/clone/vt_clone/ to avoid a warning about a
shadowed global.

Is there a specific reason that dynamically loaded libs don't use
CONST_STRING()?

leo

At the moment, each interpreter has exactly one const_cstring_table, and
there is no string_register function.  Additionally, c2str.pl would need
to maintain a separate all_cstring.str file per library.

Does this sound about right?

- Sam Ruby

Ah of course. I tend to forget that CONST_STRING doesn't really construct
a constant STRING object in the constant segment as it did with the
first approach.

leo