The attached patch is supposed to do two things:
1. Makes it possible to say ".flatten foo" as part of a
.pcc_begin_return/.pcc_end_return sequence. Remarkably, this part of
the patch is only a one-line change; the internals for call & return are
closer than the syntax.
2. Makes ".flatten" equivalent to ".flatten_arg" for all other
purposes, to emphasize the similarity.
Unfortunately, though this patch works as intended, it also has a
number of bizarre side-effects. Here's the summary of failing tests:
imcc/t/syn/macro.t 3 768 23 3 13.04% 11-12 23
t/op/string_cs.t 9 2304 28 9 32.14% 1-2 8 20 23-26 28
t/op/stringu.t 8 2048 14 8 57.14% 2-9
t/pmc/eval.t 1 256 9 1 11.11% 4
The imcc/t/syn/macro.t failures (the ones I understand, anyway) are
because it won't accept "ok" as a macro parameter name -- it thinks "ok"
is a USTRINGC and not an IDENTIFIER; the t/pmc/eval.t case seems to be
similar. The t/op/string_cs.t and t/op/stringu.t cases, on the other
hand, say
error:imcc:syntax error, unexpected LABEL
at every point where it scans a "unicode:" or "ascii:" prefix. FWIW,
all works well if I skip the lexer changes and just change pcc_return to
add "| FLATTEN target".
So clearly something is busted in the lexer. Either I made an error
(though that hardly seems likely, since the changes are so small), or I
didn't rebuild everything properly after changing imcc.y or imcc.l.
It's remotely conceivable that there's a bug in bison and/or flex (I'm
using the SuSE RPM versions bison-1.875-51.4 and flex-2.5.4a-293).
Or it could be that something else is busted. Unfortunately, I don't
have the expertise to nail it down, and am getting fed up after putting
in about 8 hours over the last five days. Is there a yacc guru out
there who could please give me a hint?
TIA,
-- Bob Rogers
http://rgrjr.dyndns.org/
Index: imcc/imcc.l
===================================================================
RCS file: /cvs/public/parrot/imcc/imcc.l,v
retrieving revision 1.124
diff -u -r1.124 imcc.l
--- imcc/imcc.l 28 Feb 2005 10:41:18 -0000 1.124
+++ imcc/imcc.l 21 Mar 2005 02:20:34 -0000
@@ -193,6 +193,7 @@
".sym" return(LOCAL);
".arg" return(ARG);
+".flatten" return(FLATTEN);
".flatten_arg" return(FLATTEN_ARG);
".sub" return(SUB);
".end" return(ESUB);
Index: imcc/imcc.y
===================================================================
RCS file: /cvs/public/parrot/imcc/imcc.y,v
retrieving revision 1.154
diff -u -r1.154 imcc.y
--- imcc/imcc.y 30 Nov 2004 09:35:10 -0000 1.154
+++ imcc/imcc.y 21 Mar 2005 02:20:35 -0000
@@ -332,7 +332,7 @@
%nonassoc <t> PARAM
%token <t> PRAGMA
-%token <t> CALL GOTO ARG FLATTEN_ARG IF UNLESS END SAVEALL RESTOREALL
+%token <t> CALL GOTO ARG FLATTEN_ARG FLATTEN IF UNLESS END SAVEALL RESTOREALL
%token <t> NEW NEWSUB NEWCLOSURE NEWCOR NEWCONT
%token <t> NAMESPACE ENDNAMESPACE CLASS ENDCLASS FIELD DOT_METHOD
%token <t> SUB SYM LOCAL CONST
@@ -719,6 +719,9 @@
pcc_arg:
ARG var { $$ = $2; }
+ | FLATTEN target { $2->type |= VT_FLATTEN; $$ = $2; }
+ /* .flatten is preferred, for symmetry with pcc_return, but .flatten_arg is
+ accepted for backwards compatibility. */
| FLATTEN_ARG target { $2->type |= VT_FLATTEN; $$ = $2; }
;
@@ -765,6 +768,7 @@
pcc_return:
RETURN var { $$ = $2; }
+ | FLATTEN target { $2->type |= VT_FLATTEN; $$ = $2; }
;
pcc_return_many:
@@ -1088,6 +1092,9 @@
arg:
var
{ $$ = $1; }
+ | FLATTEN target { $2->type |= VT_FLATTEN; $$ = $2; }
+ /* .flatten is preferred, for symmetry with pcc_return, but .flatten_arg is
+ accepted for backwards compatibility. */
| FLATTEN_ARG target
{ $2->type |= VT_FLATTEN; $$ = $2; }
;
Index: imcc/t/syn/tail.t
===================================================================
RCS file: /cvs/public/parrot/imcc/t/syn/tail.t,v
retrieving revision 1.2
diff -u -r1.2 tail.t
--- imcc/t/syn/tail.t 4 Mar 2005 17:49:04 -0000 1.2
+++ imcc/t/syn/tail.t 21 Mar 2005 02:20:35 -0000
@@ -3,7 +3,7 @@
# $Id: tail.t,v 1.2 2005/03/04 17:49:04 bernhard Exp $
use strict;
-use Parrot::Test tests => 3;
+use Parrot::Test tests => 4;
##############################
# Parrot Calling Conventions: Tail call optimization.
@@ -271,3 +271,67 @@
[doing _funcall]
_fib_step returned 3 values, 23, 20, and 3.
OUT
+
+pir_output_is(<<'CODE', <<'OUT', ".flatten_arg in return");
+
+.sub _main @MAIN
+
+ $P1 = new PerlInt
+ $P1 = 20
+ $P2 = new PerlInt
+ $P2 = 3
+ newsub $P98, .Sub, _fib_step
+ ($P3, $P4, $P5) = _funcall($P98, $P1, $P2)
+ print "_fib_step returned "
+ print argcP
+ print " values, "
+ print $P3
+ print ", "
+ print $P4
+ print ", and "
+ print $P5
+ print ".\n"
+.end
+
+.sub _funcall non_prototyped
+ .param pmc function
+ .local pmc argv
+ argv = foldup 1
+
+ $I33 = defined function
+ unless $I33 goto bad_func
+doit:
+ .pcc_begin prototyped
+ .flatten_arg argv
+ .pcc_call function
+ .pcc_end
+ $P35 = foldup
+ $I35 = $P35
+ print "[got "
+ print $I35
+ print " results]\n"
+ .pcc_begin_return
+ .flatten $P35
+ .pcc_end_return
+bad_func:
+ printerr "_funcall: Bad function.\n"
+ die
+.end
+
+## Return the sum and the two arguments as three integers.
+.sub _fib_step
+ .param pmc arg1
+ .param pmc arg2
+
+ $P1 = new PerlInt
+ $P1 = arg1 + arg2
+ .pcc_begin_return
+ .return $P1
+ .return arg1
+ .return arg2
+ .pcc_end_return
+.end
+CODE
+[got 3 results]
+_fib_step returned 3 values, 23, 20, and 3.
+OUT
