lix/src/aterm-helper.pl
2006-09-05 08:54:48 +00:00

178 lines
5.7 KiB
Perl
Executable file

#! /usr/bin/perl -w
# This program generates C/C++ code for efficiently manipulating
# ATerms. It generates functions to build and match ATerms according
# to a set of constructor definitions defined in a file read from
# standard input. A constructor is defined by a line with the
# following format:
#
# SYM | ARGS | TYPE | FUN?
#
# where SYM is the name of the constructor, ARGS is a
# whitespace-separated list of argument types, TYPE is the type of the
# resulting ATerm (which should be `ATerm' or a type synonym for
# `ATerm'), and the optional FUN is used to construct the names of the
# build and match functions (it defaults to SYM; overriding it is
# useful if there are overloaded constructors, e.g., with different
# arities). Note that SYM may be empty.
#
# A line of the form
#
# VAR = EXPR
#
# causes a ATerm variable to be generated that is initialised to the
# value EXPR.
#
# Finally, a line of the form
#
# init NAME
#
# causes the initialisation function to be called `NAME'. This
# function must be called before any of the build/match functions or
# the generated variables are used.
die if scalar @ARGV != 2;
my $syms = "";
my $init = "";
my $initFun = "init";
open HEADER, ">$ARGV[0]";
open IMPL, ">$ARGV[1]";
print HEADER "#include <aterm2.h>\n";
print HEADER "#ifdef __cplusplus\n";
print HEADER "namespace nix {\n";
print HEADER "#endif\n\n\n";
print IMPL "namespace nix {\n";
while (<STDIN>) {
next if (/^\s*$/);
if (/^\s*(\w*)\s*\|([^\|]*)\|\s*(\w+)\s*\|\s*(\w+)?/) {
my $const = $1;
my @types = split ' ', $2;
my $result = $3;
my $funname = $4;
$funname = $const unless defined $funname;
my $formals = "";
my $formals2 = "";
my $args = "";
my $unpack = "";
my $n = 1;
foreach my $type (@types) {
my $realType = $type;
$args .= ", ";
if ($type eq "string") {
# $args .= "(ATerm) ATmakeAppl0(ATmakeAFun((char *) e$n, 0, ATtrue))";
# $type = "const char *";
$type = "ATerm";
$args .= "e$n";
# !!! in the matcher, we should check that the
# argument is a string (i.e., a nullary application).
} elsif ($type eq "int") {
$args .= "(ATerm) ATmakeInt(e$n)";
} elsif ($type eq "ATermList" || $type eq "ATermBlob") {
$args .= "(ATerm) e$n";
} else {
$args .= "e$n";
}
$formals .= ", " if $formals ne "";
$formals .= "$type e$n";
$formals2 .= ", ";
$formals2 .= "$type & e$n";
my $m = $n - 1;
# !!! more checks here
if ($type eq "int") {
$unpack .= " e$n = ATgetInt((ATermInt) ATgetArgument(e, $m));\n";
} elsif ($type eq "ATermList") {
$unpack .= " e$n = (ATermList) ATgetArgument(e, $m);\n";
} elsif ($type eq "ATermBlob") {
$unpack .= " e$n = (ATermBlob) ATgetArgument(e, $m);\n";
} elsif ($realType eq "string") {
$unpack .= " e$n = ATgetArgument(e, $m);\n";
$unpack .= " if (ATgetType(e$n) != AT_APPL) return false;\n";
} else {
$unpack .= " e$n = ATgetArgument(e, $m);\n";
}
$n++;
}
my $arity = scalar @types;
print HEADER "extern AFun sym$funname;\n\n";
print IMPL "AFun sym$funname = 0;\n";
if ($arity == 0) {
print HEADER "extern ATerm const$funname;\n\n";
print IMPL "ATerm const$funname = 0;\n";
}
print HEADER "static inline $result make$funname($formals) __attribute__ ((pure, nothrow));\n";
print HEADER "static inline $result make$funname($formals) {\n";
if ($arity == 0) {
print HEADER " return const$funname;\n";
}
elsif ($arity <= 6) {
print HEADER " return (ATerm) ATmakeAppl$arity(sym$funname$args);\n";
} else {
$args =~ s/^,//;
print HEADER " ATerm array[$arity] = {$args};\n";
print HEADER " return (ATerm) ATmakeApplArray(sym$funname, array);\n";
}
print HEADER "}\n\n";
print HEADER "#ifdef __cplusplus\n";
print HEADER "static inline bool match$funname(ATerm e$formals2) {\n";
print HEADER " if (ATgetType(e) != AT_APPL || (AFun) ATgetAFun(e) != sym$funname) return false;\n";
print HEADER "$unpack";
print HEADER " return true;\n";
print HEADER "}\n";
print HEADER "#endif\n\n\n";
$init .= " sym$funname = ATmakeAFun(\"$const\", $arity, ATfalse);\n";
$init .= " ATprotectAFun(sym$funname);\n";
if ($arity == 0) {
$init .= " const$funname = (ATerm) ATmakeAppl0(sym$funname);\n";
$init .= " ATprotect(&const$funname);\n";
}
}
elsif (/^\s*(\w+)\s*=\s*(.*)$/) {
my $name = $1;
my $value = $2;
print HEADER "extern ATerm $name;\n";
print IMPL "ATerm $name = 0;\n";
$init .= " $name = $value;\n";
}
elsif (/^\s*init\s+(\w+)\s*$/) {
$initFun = $1;
}
else {
die "bad line: `$_'";
}
}
print HEADER "void $initFun();\n\n";
print HEADER "static inline const char * aterm2String(ATerm t) {\n";
print HEADER " return (const char *) ATgetName(ATgetAFun(t));\n";
print HEADER "}\n\n";
print IMPL "\n";
print IMPL "void $initFun() {\n";
print IMPL "$init";
print IMPL "}\n";
print HEADER "#ifdef __cplusplus\n";
print HEADER "}\n";
print HEADER "#endif\n\n\n";
print IMPL "}\n";
close HEADER;
close IMPL;