Current File : //proc/thread-self/root/proc/self/root/usr/share/automake-1.16/Automake/Variable.pm
# Copyright (C) 2003-2018 Free Software Foundation, Inc.
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2, or (at your option)
# any later version.
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <https://www.gnu.org/licenses/>.
package Automake::Variable;
use 5.006;
use strict;
use Carp;
use Automake::Channels;
use Automake::ChannelDefs;
use Automake::Configure_ac;
use Automake::Item;
use Automake::VarDef;
use Automake::Condition qw (TRUE FALSE);
use Automake::DisjConditions;
use Automake::General 'uniq';
use Automake::Wrap 'makefile_wrap';
require Exporter;
use vars '@ISA', '@EXPORT', '@EXPORT_OK';
@ISA = qw/Automake::Item Exporter/;
@EXPORT = qw (err_var msg_var msg_cond_var reject_var
var rvar vardef rvardef
variables
scan_variable_expansions check_variable_expansions
variable_delete
variables_dump
set_seen
require_variables
variable_value
output_variables
transform_variable_recursively);
=head1 NAME
Automake::Variable - support for variable definitions
=head1 SYNOPSIS
use Automake::Variable;
use Automake::VarDef;
# Defining a variable.
Automake::Variable::define($varname, $owner, $type,
$cond, $value, $comment,
$where, $pretty)
# Looking up a variable.
my $var = var $varname;
if ($var)
{
...
}
# Looking up a variable that is assumed to exist.
my $var = rvar $varname;
# The list of conditions where $var has been defined.
# ($var->conditions is an Automake::DisjConditions,
# $var->conditions->conds is a list of Automake::Condition.)
my @conds = $var->conditions->conds
# Access to the definition in Condition $cond.
# $def is an Automake::VarDef.
my $def = $var->def ($cond);
if ($def)
{
...
}
# When the conditional definition is assumed to exist, use
my $def = $var->rdef ($cond);
=head1 DESCRIPTION
This package provides support for Makefile variable definitions.
An C<Automake::Variable> is a variable name associated to possibly
many conditional definitions. These definitions are instances
of C<Automake::VarDef>.
Therefore obtaining the value of a variable under a given
condition involves two lookups. One to look up the variable,
and one to look up the conditional definition:
my $var = var $name;
if ($var)
{
my $def = $var->def ($cond);
if ($def)
{
return $def->value;
}
...
}
...
When it is known that the variable and the definition
being looked up exist, the above can be simplified to
return var ($name)->def ($cond)->value; # Do not write this.
but is better written
return rvar ($name)->rdef ($cond)->value;
or even
return rvardef ($name, $cond)->value;
The I<r> variants of the C<var>, C<def>, and C<vardef> methods add an
extra test to ensure that the lookup succeeded, and will diagnose
failures as internal errors (with a message which is much more
informative than Perl's warning about calling a method on a
non-object).
=cut
my $_VARIABLE_CHARACTERS = '[.A-Za-z0-9_@]+';
my $_VARIABLE_PATTERN = '^' . $_VARIABLE_CHARACTERS . "\$";
my $_VARIABLE_RECURSIVE_PATTERN =
'^([.A-Za-z0-9_@]|\$[({]' . $_VARIABLE_CHARACTERS . '[})]?)+' . "\$";
# The order in which variables should be output. (May contain
# duplicates -- only the first occurrence matters.)
my @_var_order;
# This keeps track of all variables defined by &_gen_varname.
# $_gen_varname{$base} is a hash for all variables defined with
# prefix '$base'. Values stored in this hash are the variable names.
# Keys have the form "(COND1)VAL1(COND2)VAL2..." where VAL1 and VAL2
# are the values of the variable for condition COND1 and COND2.
my %_gen_varname = ();
# $_gen_varname_n{$base} is the number of variables generated by
# _gen_varname() for $base. This is not the same as keys
# %{$_gen_varname{$base}} because %_gen_varname may also contain
# variables not generated by _gen_varname.
my %_gen_varname_n = ();
# Declare the macros that define known variables, so we can
# hint the user if she try to use one of these variables.
# Macros accessible via aclocal.
my %_am_macro_for_var =
(
CCAS => 'AM_PROG_AS',
CCASFLAGS => 'AM_PROG_AS',
EMACS => 'AM_PATH_LISPDIR',
GCJ => 'AM_PROG_GCJ',
LEX => 'AM_PROG_LEX',
LIBTOOL => 'LT_INIT',
lispdir => 'AM_PATH_LISPDIR',
pkgpyexecdir => 'AM_PATH_PYTHON',
pkgpythondir => 'AM_PATH_PYTHON',
pyexecdir => 'AM_PATH_PYTHON',
PYTHON => 'AM_PATH_PYTHON',
pythondir => 'AM_PATH_PYTHON',
);
# Macros shipped with Autoconf.
my %_ac_macro_for_var =
(
ALLOCA => 'AC_FUNC_ALLOCA',
CC => 'AC_PROG_CC',
CFLAGS => 'AC_PROG_CC',
CXX => 'AC_PROG_CXX',
CXXFLAGS => 'AC_PROG_CXX',
F77 => 'AC_PROG_F77',
FFLAGS => 'AC_PROG_F77',
FC => 'AC_PROG_FC',
FCFLAGS => 'AC_PROG_FC',
OBJC => 'AC_PROG_OBJC',
OBJCFLAGS => 'AC_PROG_OBJC',
OBJCXX => 'AC_PROG_OBJCXX',
OBJCXXFLAGS => 'AC_PROG_OBJCXX',
RANLIB => 'AC_PROG_RANLIB',
UPC => 'AM_PROG_UPC',
UPCFLAGS => 'AM_PROG_UPC',
YACC => 'AC_PROG_YACC',
);
# The name of the configure.ac file.
my $configure_ac;
# Variables that can be overridden without complaint from -Woverride
my %_silent_variable_override =
(AM_MAKEINFOHTMLFLAGS => 1,
AR => 1,
ARFLAGS => 1,
DEJATOOL => 1,
JAVAC => 1,
JAVAROOT => 1);
# Count of helper variables used to implement conditional '+='.
my $_appendvar;
# Each call to C<Automake::Variable::traverse_recursively> gets an
# unique label. This is used to detect recursively defined variables.
my $_traversal = 0;
=head2 Error reporting functions
In these functions, C<$var> can be either a variable name, or
an instance of C<Automake::Variable>.
=over 4
=item C<err_var ($var, $message, [%options])>
Uncategorized errors about variables.
=cut
sub err_var ($$;%)
{
msg_var ('error', @_);
}
=item C<msg_cond_var ($channel, $cond, $var, $message, [%options])>
Messages about conditional variable.
=cut
sub msg_cond_var ($$$$;%)
{
my ($channel, $cond, $var, $msg, %opts) = @_;
my $v = ref ($var) ? $var : rvar ($var);
msg $channel, $v->rdef ($cond)->location, $msg, %opts;
}
=item C<msg_var ($channel, $var, $message, [%options])>
Messages about variables.
=cut
sub msg_var ($$$;%)
{
my ($channel, $var, $msg, %opts) = @_;
my $v = ref ($var) ? $var : rvar ($var);
# Don't know which condition is concerned. Pick any.
my $cond = $v->conditions->one_cond;
msg_cond_var $channel, $cond, $v, $msg, %opts;
}
=item C<$bool = reject_var ($varname, $error_msg)>
Bail out with C<$error_msg> if a variable with name C<$varname> has
been defined.
Return true iff C<$varname> is defined.
=cut
sub reject_var ($$)
{
my ($var, $msg) = @_;
my $v = var ($var);
if ($v)
{
err_var $v, $msg;
return 1;
}
return 0;
}
=back
=head2 Administrative functions
=over 4
=item C<Automake::Variable::hook ($varname, $fun)>
Declare a function to be called whenever a variable
named C<$varname> is defined or redefined.
C<$fun> should take two arguments: C<$type> and C<$value>.
When type is C<''> or <':'>, C<$value> is the value being
assigned to C<$varname>. When C<$type> is C<'+'>, C<$value>
is the value being appended to C<$varname>.
=cut
use vars '%_hooks';
sub hook ($$)
{
my ($var, $fun) = @_;
$_hooks{$var} = $fun;
}
=item C<variables ([$suffix])>
Returns the list of all L<Automake::Variable> instances. (I.e., all
variables defined so far.) If C<$suffix> is supplied, return only
the L<Automake::Variable> instances that ends with C<_$suffix>.
=cut
use vars '%_variable_dict', '%_primary_dict';
sub variables (;$)
{
my ($suffix) = @_;
my @vars = ();
if ($suffix)
{
if (exists $_primary_dict{$suffix})
{
@vars = values %{$_primary_dict{$suffix}};
}
}
else
{
@vars = values %_variable_dict;
}
# The behaviour of the 'sort' built-in is undefined in scalar
# context, hence we need an ad-hoc handling for such context.
return wantarray ? sort { $a->name cmp $b->name } @vars : scalar @vars;
}
=item C<Automake::Variable::reset>
The I<forget all> function. Clears all know variables and reset some
other internal data.
=cut
sub reset ()
{
%_variable_dict = ();
%_primary_dict = ();
$_appendvar = 0;
@_var_order = ();
%_gen_varname = ();
%_gen_varname_n = ();
$_traversal = 0;
}
=item C<var ($varname)>
Return the C<Automake::Variable> object for the variable
named C<$varname> if defined. Return 0 otherwise.
=cut
sub var ($)
{
my ($name) = @_;
return $_variable_dict{$name} if exists $_variable_dict{$name};
return 0;
}
=item C<vardef ($varname, $cond)>
Return the C<Automake::VarDef> object for the variable named
C<$varname> if defined in condition C<$cond>. Return false
if the condition or the variable does not exist.
=cut
sub vardef ($$)
{
my ($name, $cond) = @_;
my $var = var $name;
return $var && $var->def ($cond);
}
# Create the variable if it does not exist.
# This is used only by other functions in this package.
sub _cvar ($)
{
my ($name) = @_;
my $v = var $name;
return $v if $v;
return _new Automake::Variable $name;
}
=item C<rvar ($varname)>
Return the C<Automake::Variable> object for the variable named
C<$varname>. Abort with an internal error if the variable was not
defined.
The I<r> in front of C<var> stands for I<required>. One
should call C<rvar> to assert the variable's existence.
=cut
sub rvar ($)
{
my ($name) = @_;
my $v = var $name;
prog_error ("undefined variable $name\n" . &variables_dump)
unless $v;
return $v;
}
=item C<rvardef ($varname, $cond)>
Return the C<Automake::VarDef> object for the variable named
C<$varname> if defined in condition C<$cond>. Abort with an internal
error if the condition or the variable does not exist.
=cut
sub rvardef ($$)
{
my ($name, $cond) = @_;
return rvar ($name)->rdef ($cond);
}
=back
=head2 Methods
C<Automake::Variable> is a subclass of C<Automake::Item>. See
that package for inherited methods.
Here are the methods specific to the C<Automake::Variable> instances.
Use the C<define> function, described latter, to create such objects.
=over 4
=cut
# Create Automake::Variable objects. This is used
# only in this file. Other users should use
# the "define" function.
sub _new ($$)
{
my ($class, $name) = @_;
my $self = Automake::Item::new ($class, $name);
$self->{'scanned'} = 0;
$self->{'last-append'} = []; # helper variable for last conditional append.
$_variable_dict{$name} = $self;
if ($name =~ /_([[:alnum:]]+)$/)
{
$_primary_dict{$1}{$name} = $self;
}
return $self;
}
# _check_ambiguous_condition ($SELF, $COND, $WHERE)
# -------------------------------------------------
# Check for an ambiguous conditional. This is called when a variable
# is being defined conditionally. If we already know about a
# definition that is true under the same conditions, then we have an
# ambiguity.
sub _check_ambiguous_condition ($$$)
{
my ($self, $cond, $where) = @_;
my $var = $self->name;
my ($message, $ambig_cond) = $self->conditions->ambiguous_p ($var, $cond);
# We allow silent variables to be overridden silently,
# by either silent or non-silent variables.
my $def = $self->def ($ambig_cond);
if ($message && $def->pretty != VAR_SILENT)
{
msg 'syntax', $where, "$message ...", partial => 1;
msg_var ('syntax', $var, "... '$var' previously defined here");
verb ($self->dump);
}
}
=item C<$bool = $var-E<gt>check_defined_unconditionally ([$parent, $parent_cond])>
Warn if the variable is conditionally defined. C<$parent> is the name
of the parent variable, and C<$parent_cond> the condition of the parent
definition. These two variables are used to display diagnostics.
=cut
sub check_defined_unconditionally ($;$$)
{
my ($self, $parent, $parent_cond) = @_;
if (!$self->conditions->true)
{
if ($parent)
{
msg_cond_var ('unsupported', $parent_cond, $parent,
"automake does not support conditional definition of "
. $self->name . " in $parent");
}
else
{
msg_var ('unsupported', $self,
"automake does not support " . $self->name
. " being defined conditionally");
}
}
}
=item C<$str = $var-E<gt>output ([@conds])>
Format all the definitions of C<$var> if C<@cond> is not specified,
else only that corresponding to C<@cond>.
=cut
sub output ($@)
{
my ($self, @conds) = @_;
@conds = $self->conditions->conds
unless @conds;
my $res = '';
my $name = $self->name;
foreach my $cond (@conds)
{
my $def = $self->def ($cond);
prog_error ("unknown condition '" . $cond->human . "' for '"
. $self->name . "'")
unless $def;
next
if $def->pretty == VAR_SILENT;
$res .= $def->comment;
my $val = $def->raw_value;
my $equals = $def->type eq ':' ? ':=' : '=';
my $str = $cond->subst_string;
if ($def->pretty == VAR_ASIS)
{
my $output_var = "$name $equals $val";
$output_var =~ s/^/$str/meg;
$res .= "$output_var\n";
}
elsif ($def->pretty == VAR_PRETTY)
{
# Suppress escaped new lines. &makefile_wrap will
# add them back, maybe at other places.
$val =~ s/\\$//mg;
my $wrap = makefile_wrap ("$str$name $equals", "$str\t",
split (' ', $val));
# If the last line of the definition is made only of
# @substitutions@, append an empty variable to make sure it
# cannot be substituted as a blank line (that would confuse
# HP-UX Make).
$wrap = makefile_wrap ("$str$name $equals", "$str\t",
split (' ', $val), '$(am__empty)')
if $wrap =~ /\n(\s*@\w+@)+\s*$/;
$res .= $wrap;
}
else # ($def->pretty == VAR_SORTED)
{
# Suppress escaped new lines. &makefile_wrap will
# add them back, maybe at other places.
$val =~ s/\\$//mg;
$res .= makefile_wrap ("$str$name $equals", "$str\t",
sort (split (' ' , $val)));
}
}
return $res;
}
=item C<@values = $var-E<gt>value_as_list ($cond, [$parent, $parent_cond])>
Get the value of C<$var> as a list, given a specified condition,
without recursing through any subvariables.
C<$cond> is the condition of interest. C<$var> does not need
to be defined for condition C<$cond> exactly, but it needs
to be defined for at most one condition implied by C<$cond>.
C<$parent> and C<$parent_cond> designate the name and the condition
of the parent variable, i.e., the variable in which C<$var> is
being expanded. These are used in diagnostics.
For example, if C<A> is defined as "C<foo $(B) bar>" in condition
C<TRUE>, calling C<rvar ('A')->value_as_list (TRUE)> will return
C<("foo", "$(B)", "bar")>.
=cut
sub value_as_list ($$;$$)
{
my ($self, $cond, $parent, $parent_cond) = @_;
my @result;
# Get value for given condition
my $onceflag;
foreach my $vcond ($self->conditions->conds)
{
if ($vcond->true_when ($cond))
{
# If there is more than one definitions of $var matching
# $cond then we are in trouble: tell the user we need a
# paddle. Continue by merging results from all conditions,
# although it doesn't make much sense.
$self->check_defined_unconditionally ($parent, $parent_cond)
if $onceflag;
$onceflag = 1;
my $val = $self->rdef ($vcond)->value;
push @result, split (' ', $val);
}
}
return @result;
}
=item C<@values = $var-E<gt>value_as_list_recursive ([%options])>
Return the contents of C<$var> as a list, split on whitespace. This
will recursively follow C<$(...)> and C<${...}> inclusions. It
preserves C<@...@> substitutions.
C<%options> is a list of option for C<Variable::traverse_recursively>
(see this method). The most useful is C<cond_filter>:
$var->value_as_list_recursive (cond_filter => $cond)
will return the contents of C<$var> and any subvariable in all
conditions implied by C<$cond>.
C<%options> can also carry options specific to C<value_as_list_recursive>.
Presently, the only such option is C<location =E<gt> 1> which instructs
C<value_as_list_recursive> to return a list of C<[$location, @values]> pairs.
=cut
sub value_as_list_recursive ($;%)
{
my ($var, %options) = @_;
return $var->traverse_recursively
(# Construct [$location, $value] pairs if requested.
sub {
my ($var, $val, $cond, $full_cond) = @_;
return [$var->rdef ($cond)->location, $val] if $options{'location'};
return $val;
},
# Collect results.
sub {
my ($var, $parent_cond, @allresults) = @_;
return map { my ($cond, @vals) = @$_; @vals } @allresults;
},
%options);
}
=item C<$bool = $var-E<gt>has_conditional_contents>
Return 1 if C<$var> or one of its subvariable was conditionally
defined. Return 0 otherwise.
=cut
sub has_conditional_contents ($)
{
my ($self) = @_;
# Traverse the variable recursively until we
# find a variable defined conditionally.
# Use 'die' to abort the traversal, and pass it '$full_cond'
# to we can find easily whether the 'eval' block aborted
# because we found a condition, or for some other error.
eval
{
$self->traverse_recursively
(sub
{
my ($subvar, $val, $cond, $full_cond) = @_;
die $full_cond if ! $full_cond->true;
return ();
},
sub { return (); });
};
if ($@)
{
return 1 if ref ($@) && $@->isa ("Automake::Condition");
# Propagate other errors.
die;
}
return 0;
}
=item C<$string = $var-E<gt>dump>
Return a string describing all we know about C<$var>.
For debugging.
=cut
sub dump ($)
{
my ($self) = @_;
my $text = $self->name . ": \n {\n";
foreach my $vcond ($self->conditions->conds)
{
$text .= " " . $vcond->human . " => " . $self->rdef ($vcond)->dump;
}
$text .= " }\n";
return $text;
}
=back
=head2 Utility functions
=over 4
=item C<@list = scan_variable_expansions ($text)>
Return the list of variable names expanded in C<$text>. Note that
unlike some other functions, C<$text> is not split on spaces before we
check for subvariables.
=cut
sub scan_variable_expansions ($)
{
my ($text) = @_;
my @result = ();
# Strip comments.
$text =~ s/#.*$//;
# Record each use of ${stuff} or $(stuff) that does not follow a $.
while ($text =~ /(?<!\$)\$(?:\{([^\}]*)\}|\(([^\)]*)\))/g)
{
my $var = $1 || $2;
# The occurrence may look like $(string1[:subst1=[subst2]]) but
# we want only 'string1'.
$var =~ s/:[^:=]*=[^=]*$//;
push @result, $var;
}
return @result;
}
=item C<check_variable_expansions ($text, $where)>
Check variable expansions in C<$text> and warn about any name that
does not conform to POSIX. C<$where> is the location of C<$text>
for the error message.
=cut
sub check_variable_expansions ($$)
{
my ($text, $where) = @_;
# Catch expansion of variables whose name does not conform to POSIX.
foreach my $var (scan_variable_expansions ($text))
{
if ($var !~ /$_VARIABLE_PATTERN/o)
{
# If the variable name contains a space, it's likely
# to be a GNU make extension (such as $(addsuffix ...)).
# Mention this in the diagnostic.
my $gnuext = "";
$gnuext = "\n(probably a GNU make extension)" if $var =~ / /;
# Accept recursive variable expansions if so desired
# (we hope they are rather portable in practice).
if ($var =~ /$_VARIABLE_RECURSIVE_PATTERN/o)
{
msg ('portability-recursive', $where,
"$var: non-POSIX recursive variable expansion$gnuext");
}
else
{
msg ('portability', $where, "$var: non-POSIX variable name$gnuext");
}
}
}
}
=item C<Automake::Variable::define($varname, $owner, $type, $cond, $value, $comment, $where, $pretty)>
Define or append to a new variable.
C<$varname>: the name of the variable being defined.
C<$owner>: owner of the variable (one of C<VAR_MAKEFILE>,
C<VAR_CONFIGURE>, or C<VAR_AUTOMAKE>, defined by L<Automake::VarDef>).
Variables can be overridden, provided the new owner is not weaker
(C<VAR_AUTOMAKE> < C<VAR_CONFIGURE> < C<VAR_MAKEFILE>).
C<$type>: the type of the assignment (C<''> for C<FOO = bar>,
C<':'> for C<FOO := bar>, and C<'+'> for C<'FOO += bar'>).
C<$cond>: the C<Condition> in which C<$var> is being defined.
C<$value>: the value assigned to C<$var> in condition C<$cond>.
C<$comment>: any comment (C<'# bla.'>) associated with the assignment.
Comments from C<+=> assignments stack with comments from the last C<=>
assignment.
C<$where>: the C<Location> of the assignment.
C<$pretty>: whether C<$value> should be pretty printed (one of
C<VAR_ASIS>, C<VAR_PRETTY>, C<VAR_SILENT>, or C<VAR_SORTED>, defined
by by L<Automake::VarDef>). C<$pretty> applies only to real
assignments. I.e., it does not apply to a C<+=> assignment (except
when part of it is being done as a conditional C<=> assignment).
This function will all run any hook registered with the C<hook>
function.
=cut
sub define ($$$$$$$$)
{
my ($var, $owner, $type, $cond, $value, $comment, $where, $pretty) = @_;
prog_error "$cond is not a reference"
unless ref $cond;
prog_error "$where is not a reference"
unless ref $where;
prog_error "pretty argument missing"
unless defined $pretty && ($pretty == VAR_ASIS
|| $pretty == VAR_PRETTY
|| $pretty == VAR_SILENT
|| $pretty == VAR_SORTED);
error $where, "bad characters in variable name '$var'"
if $var !~ /$_VARIABLE_PATTERN/o;
# ':='-style assignments are not acknowledged by POSIX. Moreover it
# has multiple meanings. In GNU make or BSD make it means "assign
# with immediate expansion", while in OSF make it is used for
# conditional assignments.
msg ('portability', $where, "':='-style assignments are not portable")
if $type eq ':';
check_variable_expansions ($value, $where);
# If there's a comment, make sure it is \n-terminated.
if ($comment)
{
chomp $comment;
$comment .= "\n";
}
else
{
$comment = '';
}
my $self = _cvar $var;
my $def = $self->def ($cond);
my $new_var = $def ? 0 : 1;
# Additional checks for Automake definitions.
if ($owner == VAR_AUTOMAKE && ! $new_var)
{
# An Automake variable must be consistently defined with the same
# sign by Automake.
if ($def->type ne $type && $def->owner == VAR_AUTOMAKE)
{
error ($def->location,
"Automake variable '$var' was set with '"
. $def->type . "=' here ...", partial => 1);
error ($where, "... and is now set with '$type=' here.");
prog_error ("Automake variable assignments should be consistently\n"
. "defined with the same sign");
}
# If Automake tries to override a value specified by the user,
# just don't let it do.
if ($def->owner != VAR_AUTOMAKE)
{
if (! exists $_silent_variable_override{$var})
{
my $condmsg = ($cond == TRUE
? '' : (" in condition '" . $cond->human . "'"));
msg_cond_var ('override', $cond, $var,
"user variable '$var' defined here$condmsg ...",
partial => 1);
msg ('override', $where,
"... overrides Automake variable '$var' defined here");
}
verb ("refusing to override the user definition of:\n"
. $self->dump ."with '" . $cond->human . "' => '$value'");
return;
}
}
# Differentiate assignment types.
# 1. append (+=) to a variable defined for current condition
if ($type eq '+' && ! $new_var)
{
$def->append ($value, $comment);
$self->{'last-append'} = [];
# Only increase owners. A VAR_CONFIGURE variable augmented in a
# Makefile.am becomes a VAR_MAKEFILE variable.
$def->set_owner ($owner, $where->clone)
if $owner > $def->owner;
}
# 2. append (+=) to a variable defined for *another* condition
elsif ($type eq '+' && ! $self->conditions->false)
{
# * Generally, $cond is not TRUE. For instance:
# FOO = foo
# if COND
# FOO += bar
# endif
# In this case, we declare an helper variable conditionally,
# and append it to FOO:
# FOO = foo $(am__append_1)
# @COND_TRUE@am__append_1 = bar
# Of course if FOO is defined under several conditions, we add
# $(am__append_1) to each definitions.
#
# * If $cond is TRUE, we don't need the helper variable. E.g., in
# if COND1
# FOO = foo1
# else
# FOO = foo2
# endif
# FOO += bar
# we can add bar directly to all definition of FOO, and output
# @COND_TRUE@FOO = foo1 bar
# @COND_FALSE@FOO = foo2 bar
my $lastappend = [];
# Do we need an helper variable?
if ($cond != TRUE)
{
# Can we reuse the helper variable created for the previous
# append? (We cannot reuse older helper variables because
# we must preserve the order of items appended to the
# variable.)
my $condstr = $cond->string;
my $key = "$var:$condstr";
my ($appendvar, $appendvarcond) = @{$self->{'last-append'}};
if ($appendvar && $condstr eq $appendvarcond)
{
# Yes, let's simply append to it.
$var = $appendvar;
$owner = VAR_AUTOMAKE;
$self = var ($var);
$def = $self->rdef ($cond);
$new_var = 0;
}
else
{
# No, create it.
my $num = ++$_appendvar;
my $hvar = "am__append_$num";
$lastappend = [$hvar, $condstr];
&define ($hvar, VAR_AUTOMAKE, '+',
$cond, $value, $comment, $where, $pretty);
# Now HVAR is to be added to VAR.
$comment = '';
$value = "\$($hvar)";
}
}
# Add VALUE to all definitions of SELF.
foreach my $vcond ($self->conditions->conds)
{
# We have a bit of error detection to do here.
# This:
# if COND1
# X = Y
# endif
# X += Z
# should be rejected because X is not defined for all conditions
# where '+=' applies.
my $undef_cond = $self->not_always_defined_in_cond ($cond);
if (! $undef_cond->false)
{
error ($where,
"cannot apply '+=' because '$var' is not defined "
. "in\nthe following conditions:\n "
. join ("\n ", map { $_->human } $undef_cond->conds)
. "\neither define '$var' in these conditions,"
. " or use\n'+=' in the same conditions as"
. " the definitions.");
}
else
{
&define ($var, $owner, '+', $vcond, $value, $comment,
$where, $pretty);
}
}
$self->{'last-append'} = $lastappend;
}
# 3. first assignment (=, :=, or +=)
else
{
# There must be no previous value unless the user is redefining
# an Automake variable or an AC_SUBST variable for an existing
# condition.
_check_ambiguous_condition ($self, $cond, $where)
unless (!$new_var
&& (($def->owner == VAR_AUTOMAKE && $owner != VAR_AUTOMAKE)
|| $def->owner == VAR_CONFIGURE));
# Never decrease an owner.
$owner = $def->owner
if ! $new_var && $owner < $def->owner;
# Assignments to a macro set its location. We don't adjust
# locations for '+='. Ideally I suppose we would associate
# line numbers with random bits of text.
$def = new Automake::VarDef ($var, $value, $comment, $where->clone,
$type, $owner, $pretty);
$self->set ($cond, $def);
push @_var_order, $var;
}
# Call any defined hook. This helps to update some internal state
# *while* parsing the file. For instance the handling of SUFFIXES
# requires this (see var_SUFFIXES_trigger).
&{$_hooks{$var}}($type, $value) if exists $_hooks{$var};
}
=item C<variable_delete ($varname, [@conds])>
Forget about C<$varname> under the conditions C<@conds>, or completely
if C<@conds> is empty.
=cut
sub variable_delete ($@)
{
my ($var, @conds) = @_;
if (!@conds)
{
delete $_variable_dict{$var};
}
else
{
for my $cond (@conds)
{
delete $_variable_dict{$var}{'defs'}{$cond};
}
}
if ($var =~ /_([[:alnum:]]+)$/)
{
delete $_primary_dict{$1}{$var};
}
}
=item C<$str = variables_dump>
Return a string describing all we know about all variables.
For debugging.
=cut
sub variables_dump ()
{
my $text = "all variables:\n{\n";
foreach my $var (variables())
{
$text .= $var->dump;
}
$text .= "}\n";
return $text;
}
=item C<$var = set_seen ($varname)>
=item C<$var = $var-E<gt>set_seen>
Mark all definitions of this variable as examined, if the variable
exists. See L<Automake::VarDef::set_seen>.
Return the C<Variable> object if the variable exists, or 0
otherwise (i.e., as the C<var> function).
=cut
sub set_seen ($)
{
my ($self) = @_;
$self = ref $self ? $self : var $self;
return 0 unless $self;
for my $c ($self->conditions->conds)
{
$self->rdef ($c)->set_seen;
}
return $self;
}
=item C<$count = require_variables ($where, $reason, $cond, @variables)>
Make sure that each supplied variable is defined in C<$cond>.
Otherwise, issue a warning showing C<$reason> (C<$reason> should be
the reason why these variables are required, for instance C<'option foo
used'>). If we know which macro can define this variable, hint the
user. Return the number of undefined variables.
=cut
sub require_variables ($$$@)
{
my ($where, $reason, $cond, @vars) = @_;
my $res = 0;
$reason .= ' but ' unless $reason eq '';
$configure_ac = find_configure_ac
unless defined $configure_ac;
VARIABLE:
foreach my $var (@vars)
{
# Nothing to do if the variable exists.
next VARIABLE
if vardef ($var, $cond);
my $text = "$reason'$var' is undefined\n";
my $v = var $var;
if ($v)
{
my $undef_cond = $v->not_always_defined_in_cond ($cond);
next VARIABLE
if $undef_cond->false;
$text .= ("in the following conditions:\n "
. join ("\n ", map { $_->human } $undef_cond->conds)
. "\n");
}
++$res;
if (exists $_am_macro_for_var{$var})
{
my $mac = $_am_macro_for_var{$var};
$text .= " The usual way to define '$var' is to add "
. "'$mac'\n to '$configure_ac' and run 'aclocal' and "
. "'autoconf' again.";
# aclocal will not warn about undefined macros unless it
# starts with AM_.
$text .= "\n If '$mac' is in '$configure_ac', make sure\n"
. " its definition is in aclocal's search path."
unless $mac =~ /^AM_/;
}
elsif (exists $_ac_macro_for_var{$var})
{
$text .= " The usual way to define '$var' is to add "
. "'$_ac_macro_for_var{$var}'\n to '$configure_ac' and "
. "run 'autoconf' again.";
}
error $where, $text, uniq_scope => US_GLOBAL;
}
return $res;
}
=item C<$count = $var->requires_variables ($reason, @variables)>
Same as C<require_variables>, but a method of Automake::Variable.
C<@variables> should be defined in the same conditions as C<$var> is
defined.
=cut
sub requires_variables ($$@)
{
my ($var, $reason, @args) = @_;
my $res = 0;
for my $cond ($var->conditions->conds)
{
$res += require_variables ($var->rdef ($cond)->location, $reason,
$cond, @args);
}
return $res;
}
=item C<variable_value ($var)>
Get the C<TRUE> value of a variable, warn if the variable is
conditionally defined. C<$var> can be either a variable name
or a C<Automake::Variable> instance (this allows calls such
as C<$var-E<gt>variable_value>).
=cut
sub variable_value ($)
{
my ($var) = @_;
my $v = ref ($var) ? $var : var ($var);
return () unless $v;
$v->check_defined_unconditionally;
my $d = $v->def (TRUE);
return $d ? $d->value : "";
}
=item C<$str = output_variables>
Format definitions for all variables.
=cut
sub output_variables ()
{
my $res = '';
# We output variables it in the same order in which they were
# defined (skipping duplicates).
my @vars = uniq @_var_order;
# Output all the Automake variables. If the user changed one,
# then it is now marked as VAR_CONFIGURE or VAR_MAKEFILE.
foreach my $var (@vars)
{
my $v = rvar $var;
foreach my $cond ($v->conditions->conds)
{
$res .= $v->output ($cond)
if $v->rdef ($cond)->owner == VAR_AUTOMAKE;
}
}
# Now dump the user variables that were defined.
foreach my $var (@vars)
{
my $v = rvar $var;
foreach my $cond ($v->conditions->conds)
{
$res .= $v->output ($cond)
if $v->rdef ($cond)->owner != VAR_AUTOMAKE;
}
}
return $res;
}
=item C<$var-E<gt>traverse_recursively (&fun_item, &fun_collect, [cond_filter =E<gt> $cond_filter], [inner_expand =E<gt> 1], [skip_ac_subst =E<gt> 1])>
Split the value of the Automake::Variable C<$var> on space, and
traverse its components recursively.
If C<$cond_filter> is an C<Automake::Condition>, process any
conditions which are true when C<$cond_filter> is true. Otherwise,
process all conditions.
We distinguish two kinds of items in the content of C<$var>.
Terms that look like C<$(foo)> or C<${foo}> are subvariables
and cause recursion. Other terms are assumed to be filenames.
Each time a filename is encountered, C<&fun_item> is called with the
following arguments:
($var, -- the Automake::Variable we are currently
traversing
$val, -- the item (i.e., filename) to process
$cond, -- the Condition for the $var definition we are
examining (ignoring the recursion context)
$full_cond) -- the full Condition, taking into account
conditions inherited from parent variables
during recursion
If C<inner_expand> is set, variable references occurring in filename
(as in C<$(BASE).ext>) are expanded before the filename is passed to
C<&fun_item>.
If C<skip_ac_subst> is set, Autoconf @substitutions@ will be skipped,
i.e., C<&fun_item> will never be called for them.
C<&fun_item> may return a list of items, they will be passed to
C<&fun_store> later on. Define C<&fun_item> or @<&fun_store> as
C<undef> when they serve no purpose.
Once all items of a variable have been processed, the result (of the
calls to C<&fun_items>, or of recursive traversals of subvariables)
are passed to C<&fun_collect>. C<&fun_collect> receives three
arguments:
($var, -- the variable being traversed
$parent_cond, -- the Condition inherited from parent
variables during recursion
@condlist) -- a list of [$cond, @results] pairs
where each $cond appear only once, and @result
are all the results for this condition.
Typically you should do C<$cond->merge ($parent_cond)> to recompute
the C<$full_cond> associated to C<@result>. C<&fun_collect> may
return a list of items, that will be used as the result of
C<Automake::Variable::traverse_recursively> (the top-level, or its
recursive calls).
=cut
# Contains a stack of 'from' and 'to' parts of variable
# substitutions currently in force.
my @_substfroms;
my @_substtos;
sub traverse_recursively ($&&;%)
{
++$_traversal;
@_substfroms = ();
@_substtos = ();
my ($var, $fun_item, $fun_collect, %options) = @_;
my $cond_filter = $options{'cond_filter'};
my $inner_expand = $options{'inner_expand'};
my $skip_ac_subst = $options{'skip_ac_subst'};
return $var->_do_recursive_traversal ($var,
$fun_item, $fun_collect,
$cond_filter, TRUE, $inner_expand,
$skip_ac_subst)
}
# The guts of Automake::Variable::traverse_recursively.
sub _do_recursive_traversal ($$&&$$$$)
{
my ($var, $parent, $fun_item, $fun_collect, $cond_filter, $parent_cond,
$inner_expand, $skip_ac_subst) = @_;
$var->set_seen;
if ($var->{'scanned'} == $_traversal)
{
err_var $var, "variable '" . $var->name() . "' recursively defined";
return ();
}
$var->{'scanned'} = $_traversal;
my @allresults = ();
my $cond_once = 0;
foreach my $cond ($var->conditions->conds)
{
if (ref $cond_filter)
{
# Ignore conditions that don't match $cond_filter.
next if ! $cond->true_when ($cond_filter);
# If we found out several definitions of $var
# match $cond_filter then we are in trouble.
# Tell the user we don't support this.
$var->check_defined_unconditionally ($parent, $parent_cond)
if $cond_once;
$cond_once = 1;
}
my @result = ();
my $full_cond = $cond->merge ($parent_cond);
my @to_process = $var->value_as_list ($cond, $parent, $parent_cond);
while (@to_process)
{
my $val = shift @to_process;
# If $val is a variable (i.e. ${foo} or $(bar), not a filename),
# handle the sub variable recursively.
# (Backslashes before '}' and ')' within brackets are here to
# please Emacs's indentation.)
if ($val =~ /^\$\{([^\}]*)\}$/ || $val =~ /^\$\(([^\)]*)\)$/)
{
my $subvarname = $1;
# If the user uses a losing variable name, just ignore it.
# This isn't ideal, but people have requested it.
next if ($subvarname =~ /\@.*\@/);
# See if the variable is actually a substitution reference
my ($from, $to);
# This handles substitution references like ${foo:.a=.b}.
if ($subvarname =~ /^([^:]*):([^=]*)=(.*)$/o)
{
$subvarname = $1;
$to = $3;
$from = quotemeta $2;
}
my $subvar = var ($subvarname);
# Don't recurse into undefined variables.
next unless $subvar;
push @_substfroms, $from;
push @_substtos, $to;
my @res = $subvar->_do_recursive_traversal ($parent,
$fun_item,
$fun_collect,
$cond_filter,
$full_cond,
$inner_expand,
$skip_ac_subst);
push (@result, @res);
pop @_substfroms;
pop @_substtos;
next;
}
# Try to expand variable references inside filenames such as
# '$(NAME).txt'. We do not handle ':.foo=.bar'
# substitutions, but it would make little sense to use this
# here anyway.
elsif ($inner_expand
&& ($val =~ /\$\{([^\}]*)\}/ || $val =~ /\$\(([^\)]*)\)/))
{
my $subvarname = $1;
my $subvar = var $subvarname;
if ($subvar)
{
# Replace the reference by its value, and reschedule
# for expansion.
foreach my $c ($subvar->conditions->conds)
{
if (ref $cond_filter)
{
# Ignore conditions that don't match $cond_filter.
next if ! $c->true_when ($cond_filter);
# If we found out several definitions of $var
# match $cond_filter then we are in trouble.
# Tell the user we don't support this.
$subvar->check_defined_unconditionally ($var,
$full_cond)
if $cond_once;
$cond_once = 1;
}
my $subval = $subvar->rdef ($c)->value;
$val =~ s/\$\{$subvarname\}/$subval/g;
$val =~ s/\$\($subvarname\)/$subval/g;
unshift @to_process, split (' ', $val);
}
next;
}
# We do not know any variable with this name. Fall through
# to filename processing.
}
elsif ($skip_ac_subst && $val =~ /^\@.+\@$/)
{
next;
}
if ($fun_item) # $var is a filename we must process
{
my $substnum=$#_substfroms;
while ($substnum >= 0)
{
$val =~ s/$_substfroms[$substnum]$/$_substtos[$substnum]/
if defined $_substfroms[$substnum];
$substnum -= 1;
}
# Make sure you update the doc of
# Automake::Variable::traverse_recursively
# if you change the prototype of &fun_item.
my @transformed = &$fun_item ($var, $val, $cond, $full_cond);
push (@result, @transformed);
}
}
push (@allresults, [$cond, @result]) if @result;
}
# We only care about _recursive_ variable definitions. The user
# is free to use the same variable several times in the same definition.
$var->{'scanned'} = -1;
return ()
unless $fun_collect;
# Make sure you update the doc of Automake::Variable::traverse_recursively
# if you change the prototype of &fun_collect.
return &$fun_collect ($var, $parent_cond, @allresults);
}
# _hash_varname ($VAR)
# --------------------
# Compute the key associated $VAR in %_gen_varname.
# See _gen_varname() below.
sub _hash_varname ($)
{
my ($var) = @_;
my $key = '';
foreach my $cond ($var->conditions->conds)
{
my @values = $var->value_as_list ($cond);
$key .= "($cond)@values";
}
return $key;
}
# _hash_values (@VALUES)
# ----------------------
# Hash @VALUES for %_gen_varname. @VALUES should be a list
# of pairs: ([$cond, @values], [$cond, @values], ...).
# See _gen_varname() below.
sub _hash_values (@)
{
my $key = '';
foreach my $pair (@_)
{
my ($cond, @values) = @$pair;
$key .= "($cond)@values";
}
return $key;
}
# ($VARNAME, $GENERATED)
# _gen_varname ($BASE, @DEFINITIONS)
# ----------------------------------
# Return a variable name starting with $BASE, that will be
# used to store definitions @DEFINITIONS.
# @DEFINITIONS is a list of pair [$COND, @OBJECTS].
#
# If we already have a $BASE-variable containing @DEFINITIONS, reuse
# it and set $GENERATED to 0. Otherwise construct a new name and set
# $GENERATED to 1.
#
# This way, we avoid combinatorial explosion of the generated
# variables. Especially, in a Makefile such as:
#
# | if FOO1
# | A1=1
# | endif
# |
# | if FOO2
# | A2=2
# | endif
# |
# | ...
# |
# | if FOON
# | AN=N
# | endif
# |
# | B=$(A1) $(A2) ... $(AN)
# |
# | c_SOURCES=$(B)
# | d_SOURCES=$(B)
#
# The generated c_OBJECTS and d_OBJECTS will share the same variable
# definitions.
#
# This setup can be the case of a testsuite containing lots (>100) of
# small C programs, all testing the same set of source files.
sub _gen_varname ($@)
{
my $base = shift;
my $key = _hash_values @_;
return ($_gen_varname{$base}{$key}, 0)
if exists $_gen_varname{$base}{$key};
my $num = 1 + ($_gen_varname_n{$base} || 0);
$_gen_varname_n{$base} = $num;
my $name = "${base}_${num}";
$_gen_varname{$base}{$key} = $name;
return ($name, 1);
}
=item C<$resvar = transform_variable_recursively ($var, $resvar, $base, $nodefine, $where, &fun_item, [%options])>
=item C<$resvar = $var-E<gt>transform_variable_recursively ($resvar, $base, $nodefine, $where, &fun_item, [%options])>
Traverse C<$var> recursively, and create a C<$resvar> variable in
which each filename in C<$var> have been transformed using
C<&fun_item>. (C<$var> may be a variable name in the first syntax.
It must be an C<Automake::Variable> otherwise.)
Helper variables (corresponding to sub-variables of C<$var>) are
created as needed, using C<$base> as prefix.
Arguments are:
$var source variable to traverse
$resvar resulting variable to define
$base prefix to use when naming subvariables of $resvar
$nodefine if true, traverse $var but do not define any variable
(this assumes &fun_item has some useful side-effect)
$where context into which variable definitions are done
&fun_item a transformation function -- see the documentation
of &fun_item in Automake::Variable::traverse_recursively.
This returns the string C<"\$($RESVAR)">.
C<%options> is a list of options to pass to
C<Variable::traverse_recursively> (see this method).
=cut
sub transform_variable_recursively ($$$$$&;%)
{
my ($var, $resvar, $base, $nodefine, $where, $fun_item, %options) = @_;
$var = ref $var ? $var : rvar $var;
my $res = $var->traverse_recursively
($fun_item,
# The code that defines the variable holding the result
# of the recursive transformation of a subvariable.
sub {
my ($subvar, $parent_cond, @allresults) = @_;
# If no definition is required, return anything: the result is
# not expected to be used, only the side effect of $fun_item
# should matter.
return 'report-me' if $nodefine;
# Cache $subvar, so that we reuse it if @allresults is the same.
my $key = _hash_varname $subvar;
$_gen_varname{$base}{$key} = $subvar->name;
# Find a name for the variable, unless this is the top-variable
# for which we want to use $resvar.
my ($varname, $generated) =
($var != $subvar) ? _gen_varname ($base, @allresults) : ($resvar, 1);
# Define the variable if we are not reusing a previously
# defined variable. At the top-level, we can also avoid redefining
# the variable if it already contains the same values.
if ($generated
&& !($varname eq $var->name && $key eq _hash_values @allresults))
{
# If the new variable is the source variable, we assume
# we are trying to override a user variable. Delete
# the old variable first.
variable_delete ($varname) if $varname eq $var->name;
# Define an empty variable in condition TRUE if there is no
# result.
@allresults = ([TRUE, '']) unless @allresults;
# Define the rewritten variable in all conditions not
# already covered by user definitions.
foreach my $pair (@allresults)
{
my ($cond, @result) = @$pair;
my $var = var $varname;
my @conds = ($var
? $var->not_always_defined_in_cond ($cond)->conds
: $cond);
foreach (@conds)
{
define ($varname, VAR_AUTOMAKE, '', $_, "@result",
'', $where, VAR_PRETTY);
}
}
}
set_seen $varname;
return "\$($varname)";
},
%options);
return $res;
}
=back
=head1 SEE ALSO
L<Automake::VarDef>, L<Automake::Condition>,
L<Automake::DisjConditions>, L<Automake::Location>.
=cut
1;
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