# New Ticket Created by Klaas-Jan Stol
# Please include the string: [perl #41636]
# in the subject line of all future correspondence about this issue.
# <URL: http://rt.perl.org/rt3/Ticket/Display.html?id=41636 >
hi,
attached a patch for pdd06 (pasm).
fixing:
* change ".sub" into ".pcc_sub"; ".sub" is illegal in pasm mode
* added constant directive
* added description of flags available to tag .pcc_sub's
* added grammar overview
I'm not sure if this patch is good enough. Let me know if anything
should change.
Also, the grammar overview may not be complete, but I can't find where
pasm is parsed; it's done through IMCC, but understanding imcc.y is a pain.
regards,
kjs
Index: docs/pdds/draft/pdd06_pasm.pod
===================================================================
--- docs/pdds/draft/pdd06_pasm.pod (revision 17213)
+++ docs/pdds/draft/pdd06_pasm.pod (working copy)
@@ -50,28 +50,68 @@
All assembly opcodes contain only ASCII lowercase letters, digits, and the
underscore.
-Upper case names are reserved for assembler directives. {{ NOTE: no
-longer true. }}
+Assembler directives are prefixed with a dot. These directives are instructions
+for the assembler and may or may not translate to a PASM instruction.
Labels all end with a colon. They may have ASCII letters, numbers, and
-underscores in them. Labels that begin with a dollar sign (the only valid spot
-in a label a dollar sign can appear) are private to the subroutine they appear
-in.
+underscores in them.
Namespaces are noted with the C<.namespace> directive. It takes a
single parameter, the name of the namespace, in the form of a
multi-dimensional key.
-Subroutine names are noted with the C<.sub> directive. It takes a
+Constants can be declared with the C<.constant> directive. It takes two
+parameters: the name of the constant and the value.
+
+Subroutine names are noted with the C<.pcc_sub> directive. It takes a
single parameter, the name of the subroutine, which is added to the
namespace's symbol table. Sub names may be any valid Unicode
-alphanumeric character and the underscore.
+alphanumeric character and the underscore. The C<.pcc_sub> directive
+may take flags to indicate when the sub should be invoked. The following
+flags are available: C<:main> to indicate that execution should start
+at the specified subroutine; C<:immediate> or C<:postcomp> to indicate
+that the sub should be run immediately after compilation; C<:load> to
+indicate that the sub should be executed when its bytecode segment is
+loaded; C<:init> to indicate the sub should be run when the file is run
+directly.
Constants don't need to be named and put in a separate section of the assembly
source. The assembler will take care of putting them in the appropriate part of
the generated bytecode.
+Below is an overview of the grammar of a PASM file.
+ pasm_file:
+ [ pasm_line '\n' ]*
+
+ pasm_line:
+ pasm_instruction
+ | constant_directive
+ | namespace_directive
+
+ pasm_instruction:
+ [ [ sub_directive ]? label ]? instruction
+
+ sub_directive:
+ ".pcc_sub" [ sub_flag ]?
+
+ sub_flag:
+ ":init" | ":main" | ":load" | ":postcomp" | ":immediate"
+
+ label:
+ identifier ":"
+
+ constant_directive:
+ ".constant" identifier literal
+
+ namespace_directive:
+ ".namespace" "[" multi_dimensional_key "]"
+
+ multi_dimensional_key:
+ quoted_string [ ";" quoted_string ]*
+
+
+
=head1 OPCODE LIST
In the following list, there may be multiple (but unlisted) versions of an
@@ -823,7 +863,7 @@
=head2 Key operations
-Keys are used to get access to individual elements of an aggregate variable.
+Keys are used to get access to individual elements of an aggregate variable.
This is done to allow for opaque, packed, and multidimensional aggregate types.
A key entry may be an integer, string, or PMC. Integers are used for array
@@ -1085,16 +1125,16 @@
=head1 VERSION
-None.
+1.9
=head2 CURRENT
Maintainer: Dan Sugalski
Class: Internals
PDD Number: 6
- Version: 1.8
+ Version: 1.9
Status: Developing
- Last Modified: 02 December 2002
+ Last Modified: 28 February 2007
PDD Format: 1
Language: English
@@ -1102,6 +1142,10 @@
=over 4
+=item Version 1.9
+
+February 28, 2007
+
=item Version 1.8
December 11, 2002
@@ -1144,6 +1188,20 @@
=over 4
+=item Version 1.9
+
+=over 4
+
+=item * Removed remark on "upper case names reserved for directives"
+
+=item * Fixed ".sub" directive, should be ".pcc_sub"
+
+=item * Added constant directive in description.
+
+=item * Added grammar overview.
+
+=back
+
=item Version 1.8
=over 4
@@ -1160,11 +1218,8 @@
=over 4
-=item * Fixed stack ops
+=item * Fixed stack ops; push, pop, and clear properly documented according to the engine's behaviour now.
-push, pop, and clear properly documented according to the engine's behaviour
-now.
-
=back
=item Version 1.6
