Edit
kc3-lang/automake/lib/Automake/Rule.pm
Alexandre Duret-Lutz
- lib/Automake/Rule.pm
-
# Copyright (C) 2003 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, write to the Free Software # Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA # 02111-1307, USA. package Automake::Rule; use strict; use Carp; use Automake::Item; use Automake::RuleDef; use Automake::ChannelDefs; use Automake::Channels; use Automake::Options; use Automake::Condition qw (TRUE FALSE); use Automake::DisjConditions; require Exporter; use vars '@ISA', '@EXPORT', '@EXPORT_OK'; @ISA = qw/Automake::Item Exporter/; @EXPORT = qw (reset register_suffix_rule suffix_rules_count suffixes rules $suffix_rules $KNOWN_EXTENSIONS_PATTERN depend %dependencies %actions accept_extensions reject_rule msg_rule msg_cond_rule err_rule err_cond_rule rule rrule ruledef rruledef); =head1 NAME Automake::Rule - support for rules definitions =head1 SYNOPSIS use Automake::Rule; use Automake::RuleDef; =head1 DESCRIPTION This package provides support for Makefile rule definitions. An C<Automake::Rule> is a rule name associated to possibly many conditional definitions. These definitions are instances of C<Automake::RuleDef>. Therefore obtaining the value of a rule under a given condition involves two lookups. One to look up the rule, and one to look up the conditional definition: my $rule = rule $name; if ($rule) { my $def = $rule->def ($cond); if ($def) { return $def->location; } ... } ... when it is known that the rule and the definition being looked up exist, the above can be simplified to return rule ($name)->def ($cond)->location; # do not write this. but is better written return rrule ($name)->rrule ($cond)->location; or even return rruledef ($name, $cond)->location; The I<r> variants of the C<rule>, C<def>, and C<ruledef> 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). =head2 Global variables =over 4 =cut my $_SUFFIX_RULE_PATTERN = '^(\.[a-zA-Z0-9_(){}$+@\-]+)(\.[a-zA-Z0-9_(){}$+@\-]+)' . "\$"; # Suffixes found during a run. use vars '@_suffixes'; # Same as $suffix_rules (declared below), but records only the # default rules supplied by the languages Automake supports. use vars '$_suffix_rules_default'; =item C<%dependencies> Holds the dependencies of targets which dependencies are factored. Typically, C<.PHONY> will appear in plenty of F<*.am> files, but must be output once. Arguably all pure dependencies could be subject to this factorization, but it is not unpleasant to have paragraphs in Makefile: keeping related stuff altogether. =cut use vars '%dependencies'; =item <%actions> Holds the factored actions. Tied to C<%dependencies>, i.e., filled only when keys exists in C<%dependencies>. =cut use vars '%actions'; =item <$suffix_rules> This maps the source extension for all suffix rule seen to a C<hash> whose keys are the possible output extensions. Note that this is transitively closed by construction: if we have exists $suffix_rules{$ext1}{$ext2} && exists $suffix_rules{$ext2}{$ext3} then we also have exists $suffix_rules{$ext1}{$ext3} So it's easy to check whether C<.foo> can be transformed to C<.$(OBJEXT)> by checking whether C<$suffix_rules{'.foo'}{'.$(OBJEXT)'}> exists. This will work even if transforming C<.foo> to C<.$(OBJEXT)> involves a chain of several suffix rules. The value of C<$suffix_rules{$ext1}{$ext2}> is the a pair C<[ $next_sfx, $dist ]> where C<$next_sfx> is target suffix for the next rule to use to reach C<$ext2>, and C<$dist> the distance to C<$ext2'>. The content of this variable should be updated via the C<register_suffix_rule> function. =cut use vars '$suffix_rules'; =item C<$KNOWN_EXTENSIONS_PATTERN> Pattern that matches all know input extensions (i.e. extensions used by the languages supported by Automake). Using this pattern (instead of `\..*$') to match extensions allows Automake to support dot-less extensions. New extensions should be registered with C<accept_extensions>. =cut use vars qw ($KNOWN_EXTENSIONS_PATTERN @_known_extensions_list); $KNOWN_EXTENSIONS_PATTERN = ""; @_known_extensions_list = (); =back =head2 Error reporting functions In these functions, C<$rule> can be either a rule name, or an instance of C<Automake::Rule>. =over 4 =item C<err_rule ($rule, $message, [%options])> Uncategorized errors about rules. =cut sub err_rule ($$;%) { msg_rule ('error', @_); } =item C<err_cond_rule ($cond, $rule, $message, [%options])> Uncategorized errors about conditional rules. =cut sub err_cond_rule ($$$;%) { msg_cond_rule ('error', @_); } =item C<msg_cond_rule ($channel, $cond, $rule, $message, [%options])> Messages about conditional rules. =cut sub msg_cond_rule ($$$$;%) { my ($channel, $cond, $rule, $msg, %opts) = @_; my $r = ref ($rule) ? $rule : rrule ($rule); msg $channel, $r->rdef ($cond)->location, $msg, %opts; } =item C<msg_rule ($channel, $targetname, $message, [%options])> Messages about rules. =cut sub msg_rule ($$$;%) { my ($channel, $rule, $msg, %opts) = @_; my $r = ref ($rule) ? $rule : rrule ($rule); # Don't know which condition is concerned. Pick any. my $cond = $r->conditions->one_cond; msg_cond_rule ($channel, $cond, $r, $msg, %opts); } =item C<$bool = reject_rule ($rule, $error_msg)> Bail out with C<$error_msg> if a rule with name C<$rule> has been defined. Return true iff C<$rule> is defined. =cut sub reject_rule ($$) { my ($rule, $msg) = @_; if (rule ($rule)) { err_rule $rule, $msg; return 1; } return 0; } =back =head2 Administrative functions =over 4 =item C<accept_extensions (@exts)> Update C<$KNOWN_EXTENSIONS_PATTERN> to recognize the extensions listed C<@exts>. Extensions should contain a dot if needed. =cut sub accept_extensions (@) { push @_known_extensions_list, @_; $KNOWN_EXTENSIONS_PATTERN = '(?:' . join ('|', map (quotemeta, @_known_extensions_list)) . ')'; } =item C<rules> Returns the list of all L<Automake::Rule> instances. (I.e., all rules defined so far.) =cut use vars '%_rule_dict'; sub rules () { return values %_rule_dict; } =item C<Automake::Rule::reset> The I<forget all> function. Clears all know rules and reset some other internal data. =cut sub reset() { %_rule_dict = (); @_suffixes = (); # The first time we initialize the variables, # we save the value of $suffix_rules. if (defined $_suffix_rules_default) { $suffix_rules = $_suffix_rules_default; } else { $_suffix_rules_default = $suffix_rules; } %dependencies = ( # Texinfoing. 'dvi' => [], 'dvi-am' => [], 'pdf' => [], 'pdf-am' => [], 'ps' => [], 'ps-am' => [], 'info' => [], 'info-am' => [], 'html' => [], 'html-am' => [], # Installing/uninstalling. 'install-data-am' => [], 'install-exec-am' => [], 'uninstall-am' => [], 'install-man' => [], 'uninstall-man' => [], 'install-info' => [], 'install-info-am' => [], 'uninstall-info' => [], 'installcheck-am' => [], # Cleaning. 'clean-am' => [], 'mostlyclean-am' => [], 'maintainer-clean-am' => [], 'distclean-am' => [], 'clean' => [], 'mostlyclean' => [], 'maintainer-clean' => [], 'distclean' => [], # Tarballing. 'dist-all' => [], # Phoning. '.PHONY' => [], ); %actions = (); } =item C<register_suffix_rule ($where, $src, $dest)> Register a suffix rules defined on C<$where> that transform files ending in C<$src> into files ending in C<$dest>. This upgrades the C<$suffix_rules> variables. =cut sub register_suffix_rule ($$$) { my ($where, $src, $dest) = @_; verb "Sources ending in $src become $dest"; push @_suffixes, $src, $dest; # When transforming sources to objects, Automake uses the # %suffix_rules to move from each source extension to # `.$(OBJEXT)', not to `.o' or `.obj'. However some people # define suffix rules for `.o' or `.obj', so internally we will # consider these extensions equivalent to `.$(OBJEXT)'. We # CANNOT rewrite the target (i.e., automagically replace `.o' # and `.obj' by `.$(OBJEXT)' in the output), or warn the user # that (s)he'd better use `.$(OBJEXT)', because Automake itself # output suffix rules for `.o' or `.obj'... $dest = '.$(OBJEXT)' if ($dest eq '.o' || $dest eq '.obj'); # Reading the comments near the declaration of $suffix_rules might # help to understand the update of $suffix_rules that follows... # Register $dest as a possible destination from $src. # We might have the create the \hash. if (exists $suffix_rules->{$src}) { $suffix_rules->{$src}{$dest} = [ $dest, 1 ]; } else { $suffix_rules->{$src} = { $dest => [ $dest, 1 ] }; } # If we know how to transform $dest in something else, then # we know how to transform $src in that "something else". if (exists $suffix_rules->{$dest}) { for my $dest2 (keys %{$suffix_rules->{$dest}}) { my $dist = $suffix_rules->{$dest}{$dest2}[1] + 1; # Overwrite an existing $src->$dest2 path only if # the path via $dest which is shorter. if (! exists $suffix_rules->{$src}{$dest2} || $suffix_rules->{$src}{$dest2}[1] > $dist) { $suffix_rules->{$src}{$dest2} = [ $dest, $dist ]; } } } # Similarly, any extension that can be derived into $src # can be derived into the same extensions as $src can. my @dest2 = keys %{$suffix_rules->{$src}}; for my $src2 (keys %$suffix_rules) { if (exists $suffix_rules->{$src2}{$src}) { for my $dest2 (@dest2) { my $dist = $suffix_rules->{$src}{$dest2} + 1; # Overwrite an existing $src2->$dest2 path only if # the path via $src is shorter. if (! exists $suffix_rules->{$src2}{$dest2} || $suffix_rules->{$src2}{$dest2}[1] > $dist) { $suffix_rules->{$src2}{$dest2} = [ $src, $dist ]; } } } } } =item C<$count = suffix_rules_count> Return the number of suffix rules added while processing the current F<Makefile> (excluding predefined suffix rules). =cut sub suffix_rules_count () { return (scalar keys %$suffix_rules) - (scalar keys %$_suffix_rules_default); } =item C<@list = suffixes> Return the list of known suffixes. =cut sub suffixes () { return @_suffixes; } =item C<rule ($rulename)> Return the C<Automake::Rule> object for the rule named C<$rulename> if defined. Return 0 otherwise. =cut sub rule ($) { my ($name) = @_; # Strip $(EXEEXT) from $name, so we can diagnose # a clash if `ctags$(EXEEXT):' is redefined after `ctags:'. $name =~ s,\$\(EXEEXT\)$,,; return $_rule_dict{$name} if exists $_rule_dict{$name}; return 0; } =item C<rule ($rulename, $cond> Return the C<Automake::RuleDef> object for the rule named C<$rulename> if defined in condition C<$cond>. Return false if the condition or the rule does not exist. =cut sub ruledef ($$) { my ($name, $cond) = @_; my $rule = rule $name; return $rule && $rule->def ($cond); } =item C<rrule ($rulename) Return the C<Automake::Rule> object for the variable named C<$rulename>. Abort with an internal error if the variable was not defined. The I<r> in front of C<var> stands for I<required>. One should call C<rvar> to assert the rule's existence. =cut sub rrule ($) { my ($name) = @_; my $r = rule $name; prog_error ("undefined rule $name\n" . &rules_dump) unless $r; return $r; } =item C<rruledef ($varname, $cond)> Return the C<Automake::RuleDef> object for the rule named C<$rulename> if defined in condition C<$cond>. Abort with an internal error if the condition or the rule does not exist. =cut sub rruledef ($$) { my ($name, $cond) = @_; return rrule ($name)->rdef ($cond); } # Create the variable if it does not exist. # This is used only by other functions in this package. sub _crule ($) { my ($name) = @_; my $r = rule $name; return $r if $r; return _new Automake::Rule $name; } sub _new ($$) { my ($class, $name) = @_; # Strip $(EXEEXT) from $name, so we can diagnose # a clash if `ctags$(EXEEXT):' is redefined after `ctags:'. (my $keyname = $name) =~ s,\$\(EXEEXT\)$,,; my $self = Automake::Item::new ($class, $name); $_rule_dict{$keyname} = $self; return $self; } =itcem C<@conds = define ($rulename, $source, $owner, $cond, $where)> Define a new rule. C<$rulename> is the list of targets. C<$source> is the filename the rule comes from. C<$owner> is the owner of the rule (C<RULE_AUTOMAKE> or C<RULE_USER>). C<$cond> is the C<Automake::Condition> under which the rule is defined. C<$where> is the C<Automake::Location> where the rule is defined. Returns a (possibly empty) list of C<Automake::Condition>s where the rule's definition should be output. =cut sub define ($$$$$) { my ($target, $source, $owner, $cond, $where) = @_; prog_error "$where is not a reference" unless ref $where; prog_error "$cond is not a reference" unless ref $cond; # Don't even think about defining a rule in condition FALSE. return () if $cond == FALSE; # For now `foo:' will override `foo$(EXEEXT):'. This is temporary, # though, so we emit a warning. (my $noexe = $target) =~ s,\$\(EXEEXT\)$,,; my $noexerule = rule $noexe; my $tdef = $noexerule ? $noexerule->def ($cond) : undef; if ($noexe ne $target && $tdef && $noexerule->name ne $target) { # The no-exeext option enables this feature. if (! option 'no-exeext') { msg ('obsolete', $tdef->location, "deprecated feature: target `$noexe' overrides " . "`$noexe\$(EXEEXT)'\n" . "change your target to read `$noexe\$(EXEEXT)'"); msg ('obsolete', $where, "target `$target' was defined here"); } # Don't `return ()' now, as this might hide target clashes # detected below. } # A GNU make-style pattern rule has a single "%" in the target name. msg ('portability', $where, "`%'-style pattern rules are a GNU make extension") if $target =~ /^[^%]*%[^%]*$/; # Diagnose target redefinitions. if ($tdef) { my $oldowner = $tdef->owner; # Ok, it's the name target, but the name maybe different because # `foo$(EXEEXT)' and `foo' have the same key in our table. my $oldname = $tdef->name; # Don't mention true conditions in diagnostics. my $condmsg = $cond == TRUE ? '' : " in condition `" . $cond->human . "'"; if ($owner == RULE_USER) { if ($oldowner == RULE_USER) { # Ignore `%'-style pattern rules. We'd need the # dependencies to detect duplicates, and they are # already diagnosed as unportable by -Wportability. if ($target !~ /^[^%]*%[^%]*$/) { ## FIXME: Presently we can't diagnose duplicate user rules ## because we doesn't distinguish rules with commands ## from rules that only add dependencies. E.g., ## .PHONY: foo ## .PHONY: bar ## is legitimate. (This is phony.test.) # msg ('syntax', $where, # "redefinition of `$target'$condmsg...", partial => 1); # msg_cond_rule ('syntax', $cond, $target, # "... `$target' previously defined here"); } # Return so we don't redefine the rule in our tables, # don't check for ambiguous condition, etc. The rule # will be output anyway beauce &read_am_file ignore the # return code. return (); } else { # Since we parse the user Makefile.am before reading # the Automake fragments, this condition should never happen. prog_error ("user target `$target'$condmsg seen after Automake's" . " definition\nfrom " . $tdef->source); } } else # $owner == RULE_AUTOMAKE { if ($oldowner == RULE_USER) { # -am targets listed in %dependencies support a -local # variant. If the user tries to override TARGET or # TARGET-am for which there exists a -local variant, # just tell the user to use it. my $hint = 0; my $noam = $target; $noam =~ s/-am$//; if (exists $dependencies{"$noam-am"}) { $hint = "consider using $noam-local instead of $target"; } msg_cond_rule ('override', $cond, $target, "user target `$target' defined here" . "$condmsg...", partial => 1); msg ('override', $where, "... overrides Automake target `$oldname' defined here", partial => $hint); msg_cond_rule ('override', $cond, $target, $hint) if $hint; # Don't overwrite the user definition of TARGET. return (); } else # $oldowner == RULE_AUTOMAKE { # Automake should ignore redefinitions of its own # rules if they came from the same file. This makes # it easier to process a Makefile fragment several times. # Hower it's an error if the target is defined in many # files. E.g., the user might be using bin_PROGRAMS = ctags # which clashes with our `ctags' rule. # (It would be more accurate if we had a way to compare # the *content* of both rules. Then $targets_source would # be useless.) my $oldsource = $tdef->source; return () if $source eq $oldsource && $target eq $oldname; msg ('syntax', $where, "redefinition of `$target'$condmsg...", partial => 1); msg_cond_rule ('syntax', $cond, $target, "... `$oldname' previously defined here"); return (); } } # Never reached. prog_error ("Unreachable place reached."); } # Conditions for which the rule should be defined. my @conds = $cond; # Check ambiguous conditional definitions. my $rule = _crule $target; my ($message, $ambig_cond) = $rule->conditions->ambiguous_p ($target, $cond); if ($message) # We have an ambiguity. { if ($owner == RULE_USER) { # For user rules, just diagnose the ambiguity. msg 'syntax', $where, "$message ...", partial => 1; msg_cond_rule ('syntax', $ambig_cond, $target, "... `$target' previously defined here"); return (); } else { # FIXME: for Automake rules, we can't diagnose ambiguities yet. # The point is that Automake doesn't propagate conditions # everywhere. For instance &handle_PROGRAMS doesn't care if # bin_PROGRAMS was defined conditionally or not. # On the following input # if COND1 # foo: # ... # else # bin_PROGRAMS = foo # endif # &handle_PROGRAMS will attempt to define a `foo:' rule # in condition TRUE (which conflicts with COND1). Fixing # this in &handle_PROGRAMS and siblings seems hard: you'd # have to explain &file_contents what to do with a # condition. So for now we do our best *here*. If `foo:' # was already defined in condition COND1 and we want to define # it in condition TRUE, then define it only in condition !COND1. # (See cond14.test and cond15.test for some test cases.) @conds = $rule->not_always_defined_in_cond ($cond)->conds; # No conditions left to define the rule. # Warn, because our workaround is meaningless in this case. if (scalar @conds == 0) { msg 'syntax', $where, "$message ...", partial => 1; msg_cond_rule ('syntax', $ambig_cond, $target, "... `$target' previously defined here"); return (); } } } # Finally define this rule. for my $c (@conds) { my $def = new Automake::RuleDef ($target, '', $where->clone, $owner, $source); $rule->set ($c, $def); } # We honor inference rules with multiple targets because many # make support this and people use it. However this is disallowed # by POSIX. We'll print a warning later. my $target_count = 0; my $inference_rule_count = 0; for my $t (split (' ', $target)) { ++$target_count; # Check if the rule is a suffix rule: either it's a rule for # two known extensions... if ($t =~ /^($KNOWN_EXTENSIONS_PATTERN)($KNOWN_EXTENSIONS_PATTERN)$/ # ...or it's a rule with unknown extensions (.i.e, the rule # looks like `.foo.bar:' but `.foo' or `.bar' are not # declared in SUFFIXES and are not known language # extensions). Automake will complete SUFFIXES from # @suffixes automatically (see handle_footer). || ($t =~ /$_SUFFIX_RULE_PATTERN/o && accept_extensions($1))) { ++$inference_rule_count; register_suffix_rule ($where, $1, $2); } } # POSIX allows multiple targets before the colon, but disallows # definitions of multiple inference rules. It's also # disallowed to mix plain targets with inference rules. msg ('portability', $where, "Inference rules can have only one target before the colon (POSIX).") if $inference_rule_count > 0 && $target_count > 1; return @conds; } =item C<depend ($target, @deps)> Adds C<@deps> to the dependencies of target C<$target>. This should be used only with factored targets (those appearing in C<%dependees>). =cut sub depend ($@) { my ($category, @dependees) = @_; push (@{$dependencies{$category}}, @dependees); } =back =head1 SEE ALSO L<Automake::RuleDef>, L<Automake::Condition>, L<Automake::DisjConditions>, L<Automake::Location>. =cut 1; ### Setup "GNU" style for perl-mode and cperl-mode. ## Local Variables: ## perl-indent-level: 2 ## perl-continued-statement-offset: 2 ## perl-continued-brace-offset: 0 ## perl-brace-offset: 0 ## perl-brace-imaginary-offset: 0 ## perl-label-offset: -2 ## cperl-indent-level: 2 ## cperl-brace-offset: 0 ## cperl-continued-brace-offset: 0 ## cperl-label-offset: -2 ## cperl-extra-newline-before-brace: t ## cperl-merge-trailing-else: nil ## cperl-continued-statement-offset: 2 ## End: