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Here is the resend with code inline
]
Leopold Toetsch <[EMAIL PROTECTED]> writes:
> We currently have constant Key and Sub PMCs both created from the
> packfile at load time. They live in the constant_table pointing to a
> constant PMC pool. But we need more.
>
>
> We have allover the core code like this:
>
> string_from_cstring(interpreter, "pIt", 0)
> key = key_new_cstring(interpreter, "_message");
>
> to create some STRINGs or entries in hashes. The keys should be
> constant PMCs and they should be shared as well as the STRINGs.
>
> We need this in objects.c ("\0\0anonymous"), for setting standard
> property names internally and for the current hash based
> implementation of Exceptions.
[...]
Some time ago I did some experiments with initialising strings at
compile time. With some preprocessor magic and a perl program scanning
the c-file I got it running.
The changes to an existing c-file are minimal: At the beginning add a
#include "FILE.str" and replace all these string_form_cstring with
_S("text"). The _S macros are replaced by static string_structures
with static initialisers. These string structures are in the ro-data
segement of the executable and should load really fast. No calls to
any functions.
===== c2str.pl
#! perl
use Text::Balanced qw(extract_bracketed);
use Data::Dumper;
die "$0: Usage $0 FILE.c" unless $#ARGV == 0;
my $file = shift @ARGV;
$file =~ s/\.c$//;
my $infile = $file . '.c';
my $outfile = $file . '.str';
die "$0: $infile: $!" unless -e $infile;
print <<'HEADER';
/*
* !!!!!!! DO NOT EDIT THIS FILE !!!!!!!
*
* This file is generated automatically from '$infile'
* by $0.
*
* Any changes made here will be lost!
*
*/
#define CONCAT(a,b) a##b
#define _S(name) (__PARROT_STATIC_STR(__LINE__))
#define __PARROT_STATIC_STR(line) CONCAT(&static_string_, line)
#include <parrot/pobj.h>
#if ! DISABLE_GC_DEBUG
# define GC_DEBUG_VERSION ,0
#else
# define GC_DEBUG_VERSION
#endif
HEADER
my %known_strings = ();
sub output_string {
my ($text, $line) = @_;
if (exists $known_strings{$text}) {
<<"DATA";
#define static_string_${line} static_string_$known_strings{$text}
DATA
}
else {
$known_strings{$text} = $line;
<<"DATA";
static const char static_string_${line}_data\[\] = $text;
static const struct parrot_string_t static_string_${line} = {
{ /* pobj_t */
{{
(void*)static_string_${line}_data,
sizeof(static_string_${line}_data)
}},
PObj_constant_FLAG
GC_DEBUG_VERSION
},
sizeof(static_string_${line}_data),
(void*)static_string_${line}_data,
sizeof(static_string_${line}_data) - 1,
NULL,
NULL,
0
};
DATA
}
}
open IN, $infile;
my $line = 0;
while (<IN>) {
$line++;
next if m/^\s*\#/; # ignore preprocessor
next unless s/.*\b_S\b//;
my $str = extract_bracketed $_, '(")';
print output_string (substr($str,1,-1), $line);
}
===== example.c
/*
* example.c
*
* demonstrating static allocation of string
*
* to compile:
* perl c2str.pl example.c > example.str
* gcc -o example -Iinclude example.c blib/lib/libparrot.a -lm -ldl
*/
#include <parrot/parrot.h>
#include "example.str"
int
main(int argc, char* argv[]) {
struct Parrot_Interp * interpreter;
interpreter = Parrot_new();
Parrot_init(interpreter, &interpreter);
PIO_putps(interpreter, PIO_STDOUT(interpreter), _S("foo\n"));
PIO_putps(interpreter, PIO_STDOUT(interpreter), _S("bar\n"));
PIO_putps(interpreter, PIO_STDOUT(interpreter), _S("foo\n"));
return 0;
}
=====
Issues with this are:
* My macro vodoo is base on __LINE__ so only one _S directive per line
* the strings are local to one compilation unit (but that is not
diffrent from the c-string constants)
* It exposes the internal structure of PObj (this does not bother us at
the moment, nearly every file includes <parrot/parrot.h>)
* The encoding/chartype must be set to 0 or we get a many relocations,
the string functions have to deal with this case.
May a scheme like this can be used for keys too.
> Comments welcome
> leo
Same here
boe
--
Juergen Boemmels [EMAIL PROTECTED]
Fachbereich Physik Tel: ++49-(0)631-205-2817
Universitaet Kaiserslautern Fax: ++49-(0)631-205-3906
PGP Key fingerprint = 9F 56 54 3D 45 C1 32 6F 23 F6 C7 2F 85 93 DD 47
