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|
// file : build/target -*- C++ -*-
// copyright : Copyright (c) 2014-2015 Code Synthesis Ltd
// license : MIT; see accompanying LICENSE file
#ifndef BUILD_TARGET
#define BUILD_TARGET
#include <map>
#include <string>
#include <vector>
#include <memory> // unique_ptr
#include <cstddef> // size_t
#include <cstdint> // uint8_t
#include <functional> // reference_wrapper
#include <ostream>
#include <cassert>
#include <utility> // move(), forward(), declval()
#include <iterator>
#include <type_traits>
#include <butl/utility> // reverse_iterate()
#include <butl/multi-index> // map_iterator_adapter
#include <build/types>
#include <build/utility>
#include <build/scope>
#include <build/variable>
#include <build/operation>
#include <build/target-type>
#include <build/target-key>
#include <build/prerequisite>
namespace build
{
class scope;
class target;
target&
search (prerequisite&); // From <build/algorithm>.
// Target state.
//
enum class target_state: std::uint8_t
{
// The order of the enumerators is arranged so that their integral
// values indicate whether one "overrides" the other in the merge
// operator (see below).
//
unknown,
unchanged,
postponed,
changed,
failed,
group // Target's state is the group's state.
};
std::ostream&
operator<< (std::ostream&, target_state);
inline target_state&
operator |= (target_state& l, target_state r)
{
if (static_cast<std::uint8_t> (r) > static_cast<std::uint8_t> (l))
l = r;
return l;
}
// Recipe.
//
// The returned target state should be changed, unchanged, or
// postponed, though you shouldn't be returning postponed
// directly. If there is an error, then the recipe should
// throw rather than returning failed.
//
// The return value of the recipe is used to update the target
// state except if the state was manually set by the recipe to
// target_state::group. Note that in this case the returned by
// the recipe value is still used as the resulting target state
// so it should match the group's state.
//
using recipe_function = target_state (action, target&);
using recipe = std::function<recipe_function>;
// Commonly-used recipes. The default recipe executes the action on
// all the prerequisites in a loop, skipping ignored. Specifically,
// for actions with the "first" execution mode, it calls
// execute_prerequisites() while for those with the "last" mode --
// reverse_execute_prerequisites(); see <build/operation>,
// <build/algorithm> for details. The group recipe call's the group's
// recipe.
//
extern const recipe empty_recipe;
extern const recipe noop_recipe;
extern const recipe default_recipe;
extern const recipe group_recipe;
target_state
noop_action (action, target&); // Defined in <build/algorithm>.
target_state
group_action (action, target&); // Defined in <build/algorithm>.
// Prerequisite references as used in the target::prerequisites list
// below.
//
struct prerequisite_ref: std::reference_wrapper<prerequisite>
{
typedef std::reference_wrapper<prerequisite> base;
using base::base;
// Return true if this reference belongs to the target's prerequisite
// list. Note that this test only works if you use references to
// the container elements and the container hasn't been resized
// since such a reference was obtained. Normally this function is
// used when iterating over a combined prerequisites range (see
// group_prerequisites below).
//
bool
belongs (const target&) const;
};
// A view of target group members.
//
struct group_view
{
target* const* members; // NULL means not yet known.
std::size_t count;
};
// Target.
//
class target
{
public:
typedef build::action action_type;
virtual
~target () = default;
target (const target&) = delete;
target& operator= (const target&) = delete;
target (dir_path d, std::string n, const std::string* e)
: dir (std::move (d)), name (std::move (n)), ext (e) {}
// Reset the target before matching a rule for it. The
// default implementation clears prerequisite_targets.
//
virtual void
reset (action_type);
const dir_path dir; // Absolute and normalized.
const std::string name;
const std::string* ext; // Extension, NULL means unspecified,
// empty means no extension.
// Target group to which this target belongs, if any. Note that
// we assume that the group and all its members are in the same
// scope (for example, in variable lookup). We also don't support
// nested groups.
//
// The semantics of the interaction between the group and its
// members and what it means to, say, update the group, is
// unspecified and determined by the group's type. In particular,
// a group can be created out of member types that have no idea
// they are part of this group (e.g., cli.cxx{}).
//
// Normally, however, there are two kinds of groups: "alternatives"
// and "combination". In an alternatives group, normally one of the
// members is selected when the group is mentioned as a prerequisite
// with, perhaps, an exception for special rules, like aliases, where
// it makes more sense to treat the group as a whole. In this case we
// say that the rule "semantically recognizes" the group and picks
// some of its members.
//
// Updating an alternatives group as a whole can mean updating some
// subset of its members (e.g., lib{}). Or the group may not support
// this at all (e.g., obj{}).
//
// In a combination group, when a group is updated, normally all
// members are updates (and usually with a single command), though
// there could be some members that are omitted, depending on the
// configuration (e.g., an inline file not/being generated). When
// a combination group is mentioned as a prerequisite, the rule
// is usually interested in the individual members rather than
// the whole group. For example, a C++ compile rule would like to
// "see" the ?xx{} members when it gets a cli.cxx{} group.
//
// Which brings us to the group iteration mode. The target type
// contains a member called see_through that indicates whether the
// default iteration mode for the group should be "see through";
// that is, whether we see the members or the group itself. For
// the iteration support itself, see the *_prerequisite_members()
// machinery below.
//
target* group {nullptr};
// You should not call this function directly; rather use
// resolve_group_members() from <build/algorithm>.
//
virtual group_view
group_members (action_type) const;
target_key
key () const {return target_key {&type (), &dir, &name, &ext};}
// Scoping.
//
public:
// Most qualified scope that contains this target.
//
scope&
base_scope () const;
// Root scope of a project that contains this target. Note that
// a target can be out of any (known) project root in which case
// this function asserts. If you need to detect this situation,
// then use base_scope().root_scope() expression instead.
//
scope&
root_scope () const;
// Root scope of a strong amalgamation that contains this target.
// The same notes as to root_scope() apply.
//
scope&
strong_scope () const {return *root_scope ().strong_scope ();}
bool
in (const scope& s) const
{
return
(s.out_path_ != nullptr && dir.sub (*s.out_path_)) ||
(s.src_path_ != nullptr && dir.sub (*s.src_path_));
}
// Prerequisites.
//
public:
typedef std::vector<prerequisite_ref> prerequisites_type;
prerequisites_type prerequisites;
// Targets to which prerequisites resolve for this recipe. Note
// that unlike prerequisite::target, these can be resolved to
// group members. NULL means the target should be skipped (or
// the rule may simply not add such a target to the list).
//
// Note also that it is possible the target can vary from
// action to action, just like recipes. We don't need to keep
// track of the action here since the targets will be updated
// if the recipe is updated, normally as part of rule::apply().
//
typedef std::vector<target*> prerequisite_targets_type;
prerequisite_targets_type prerequisite_targets;
// Check if there are any prerequisites, taking into account
// group prerequisites.
//
bool
has_prerequisites () const
{
return !prerequisites.empty () ||
(group != nullptr && !group->prerequisites.empty ());
}
// Target-specific variables.
//
public:
variable_map vars;
// Lookup, including in groups to which this target belongs and
// then in outer scopes (including target type/pattern-specific
// variables). If you only want to lookup in this target, do it
// on the variable map directly.
//
lookup<const value>
operator[] (const variable&) const;
lookup<const value>
operator[] (const std::string& name) const
{
return operator[] (var_pool.find (name));
}
// Return a value suitable for assignment. See class scope for
// details.
//
value&
assign (const variable& var) {return vars.assign (var).first;}
value&
assign (const std::string& name) {return vars.assign (name).first;}
// Return a value suitable for appending. See class scope for
// details.
//
value&
append (const variable&);
value&
append (const std::string& name)
{
return append (var_pool.find (name));
}
public:
target_state raw_state;
target_state
state () const
{
return raw_state != target_state::group ? raw_state : group->raw_state;
}
// Number of direct targets that depend on this target in the current
// action. It is incremented during the match phase and then decremented
// during execution, before running the recipe. As a result, the recipe
// can detect the last chance (i.e., last dependent) to execute the
// command (see also the first/last execution modes in <operation>).
//
// Note that setting a new recipe (which happens when we match the rule
// and which in turn is triggered by the first dependent) clears this
// counter. However, if the previous action was the same as the current,
// then the existing recipe is reused. In this case, however, the counter
// should have been decremented to 0 naturally, as part of the previous
// action execution.
//
std::size_t dependents;
public:
action_type action; // Action this recipe is for.
public:
typedef build::recipe recipe_type;
const recipe_type&
recipe (action_type a) const {return a > action ? empty_recipe : recipe_;}
void
recipe (action_type, recipe_type);
// Target type info.
//
public:
template <typename T>
T*
is_a () {return dynamic_cast<T*> (this);}
template <typename T>
const T*
is_a () const {return dynamic_cast<const T*> (this);}
// Dynamic derivation to support define.
//
const target_type* derived_type = nullptr;
const target_type&
type () const
{
return derived_type != nullptr ? *derived_type : dynamic_type ();
}
virtual const target_type& dynamic_type () const = 0;
static const target_type static_type;
private:
recipe_type recipe_;
};
std::ostream&
operator<< (std::ostream&, const target&);
// A "range" that presents the prerequisites of a group and one of
// its members as one continuous sequence, or, in other words, as
// if they were in a single container. The group's prerequisites
// come first followed by the member's. If you need to see them
// in the other direction, iterate in reverse, for example:
//
// for (prerequisite_ref& pr: group_prerequisites (t))
//
// for (prerequisite_ref& pr: reverse_iterate (group_prerequisites (t))
//
// Note that in this case the individual elements of each list will
// also be traversed in reverse, but that's what you usually want,
// anyway.
//
class group_prerequisites
{
public:
typedef target::prerequisites_type prerequisites_type;
explicit
group_prerequisites (target& t): t_ (t) {}
struct iterator
{
typedef prerequisites_type::iterator base_iterator;
typedef base_iterator::value_type value_type;
typedef base_iterator::pointer pointer;
typedef base_iterator::reference reference;
typedef base_iterator::difference_type difference_type;
typedef std::bidirectional_iterator_tag iterator_category;
iterator () {}
iterator (target* t, prerequisites_type* c, base_iterator i)
: t_ (t), c_ (c), i_ (i) {}
iterator&
operator++ ()
{
if (++i_ == c_->end () && c_ != &t_->prerequisites)
{
c_ = &t_->prerequisites;
i_ = c_->begin ();
}
return *this;
}
iterator
operator++ (int) {iterator r (*this); operator++ (); return r;}
iterator&
operator-- ()
{
if (i_ == c_->begin () && c_ == &t_->prerequisites)
{
c_ = &t_->group->prerequisites;
i_ = c_->end ();
}
--i_;
return *this;
}
iterator
operator-- (int) {iterator r (*this); operator-- (); return r;}
reference operator* () const {return *i_;}
pointer operator-> () const {return i_.operator -> ();}
friend bool
operator== (const iterator& x, const iterator& y)
{
return x.t_ == y.t_ && x.c_ == y.c_ && x.i_ == y.i_;
}
friend bool
operator!= (const iterator& x, const iterator& y) {return !(x == y);}
private:
target* t_ {nullptr};
prerequisites_type* c_ {nullptr};
base_iterator i_;
};
typedef std::reverse_iterator<iterator> reverse_iterator;
iterator
begin () const
{
auto& c ((t_.group != nullptr && !t_.group->prerequisites.empty ()
? *t_.group : t_).prerequisites);
return iterator (&t_, &c, c.begin ());
}
iterator
end () const
{
auto& c (t_.prerequisites);
return iterator (&t_, &c, c.end ());
}
reverse_iterator
rbegin () const {return reverse_iterator (end ());}
reverse_iterator
rend () const {return reverse_iterator (begin ());}
std::size_t
size () const
{
return t_.prerequisites.size () +
(t_.group != nullptr ? t_.group->prerequisites.size () : 0);
}
private:
target& t_;
};
// A member of a prerequisite. If 'target' is NULL, then this is the
// prerequisite itself. Otherwise, it is its member. In this case
// 'prerequisite' still refers to the prerequisite.
//
struct prerequisite_member
{
typedef build::target target_type;
typedef build::prerequisite prerequisite_type;
prerequisite_ref& prerequisite;
target_type* target;
template <typename T>
bool
is_a () const
{
return target != nullptr
? target->is_a<T> () != nullptr
: prerequisite.get ().is_a<T> ();
}
prerequisite_key
key () const
{
return target != nullptr
? prerequisite_key {&prerequisite.get ().proj, target->key (), nullptr}
: prerequisite.get ().key ();
}
const build::target_type&
type () const
{
return target != nullptr ? target->type () : prerequisite.get ().type;
}
const std::string&
name () const
{
return target != nullptr ? target->name : prerequisite.get ().name;
}
const std::string*
proj () const
{
// Target cannot be project-qualified.
//
return target != nullptr ? nullptr : prerequisite.get ().proj;
}
target_type&
search () const
{
return target != nullptr ? *target : build::search (prerequisite);
}
prerequisite_type&
as_prerequisite (tracer&) const;
};
inline std::ostream&
operator<< (std::ostream& os, const prerequisite_member& pm)
{
return os << pm.key ();
}
// A "range" that presents a sequence of prerequisites (e.g., from
// group_prerequisites()) as a sequence of prerequisite_member's. For
// each group prerequisite you will "see" either the prerequisite
// itself or all its members, depending on the default iteration
// mode of the target group type. You can skip the rest of the
// group members with leave_group() and you can force iteration
// over the members with enter_group(). Usage:
//
// for (prerequisite_member pm: prerequisite_members (a, ...))
//
// Where ... can be:
//
// t.prerequisites
// reverse_iterate(t.prerequisites)
// group_prerequisites (t)
// reverse_iterate (group_prerequisites (t))
//
// But use shortcuts instead:
//
// prerequisite_members (a, t)
// reverse_prerequisite_members (a, t)
// group_prerequisite_members (a, t)
// reverse_group_prerequisite_members (a, t)
//
template <typename T>
class prerequisite_members_range;
template <typename T>
inline prerequisite_members_range<T>
prerequisite_members (action a, T&& x, bool members = true)
{
return prerequisite_members_range<T> (a, std::forward<T> (x), members);
}
template <typename T>
class prerequisite_members_range
{
public:
prerequisite_members_range (action a, T&& r, bool m)
: a_ (a), members_ (m), r_ (std::forward<T> (r)), e_ (r_.end ()) {}
using base_iterator = decltype (std::declval<T> ().begin ());
struct iterator
{
typedef prerequisite_member value_type;
typedef const value_type* pointer;
typedef const value_type& reference;
typedef typename base_iterator::difference_type difference_type;
typedef std::forward_iterator_tag iterator_category;
iterator (): r_ (nullptr) {}
iterator (const prerequisite_members_range* r, const base_iterator& i)
: r_ (r), i_ (i), g_ {nullptr, 0}
{
if (r_->members_ && i_ != r_->e_ && i_->get ().type.see_through)
{
bool r (switch_members ());
assert (r); // Group could not be resolved.
}
}
iterator& operator++ ();
iterator operator++ (int) {iterator r (*this); operator++ (); return r;}
// Skip iterating over the rest of this group's members, if any.
// Note that the only valid operation after this call is to
// increment the iterator.
//
void
leave_group ()
{
// Pretend we are on the last member of some group.
//
j_ = 0;
g_.count = 1;
}
// Iterate over this group's members. Return false if the member
// information is not available. Similar to leave_group(), you
// should increment the iterator after calling this function
// (provided it returned true).
//
bool
enter_group ()
{
bool r (switch_members ());
if (r)
--j_; // Compensate for the increment that will follow.
return r;
}
value_type operator* () const
{
return value_type {*i_, g_.count != 0 ? g_.members[j_ - 1] : nullptr};
}
pointer operator-> () const
{
static_assert (
std::is_trivially_destructible<prerequisite_member>::value,
"prerequisite_member is not trivially destructible");
return new (&m_)
value_type {*i_, g_.count != 0 ? g_.members[j_ - 1] : nullptr};
}
friend bool
operator== (const iterator& x, const iterator& y)
{
return x.i_ == y.i_ &&
x.g_.count == y.g_.count &&
(x.g_.count == 0 || x.j_ == y.j_);
}
friend bool
operator!= (const iterator& x, const iterator& y) {return !(x == y);}
private:
bool
switch_members ();
private:
const prerequisite_members_range* r_;
base_iterator i_;
group_view g_;
std::size_t j_; // 1-based index, to support enter_group().
mutable std::aligned_storage<sizeof (prerequisite_member),
alignof (prerequisite_member)>::type m_;
};
iterator
begin () const {return iterator (this, r_.begin ());}
iterator
end () const {return iterator (this, e_);}
private:
action a_;
bool members_; // Go into group members by default?
T r_;
base_iterator e_;
};
// prerequisite_members(t.prerequisites)
//
inline auto
prerequisite_members (action a, target& t, bool members = true)
{
return prerequisite_members (a, t.prerequisites, members);
}
// prerequisite_members(reverse_iterate(t.prerequisites))
//
inline auto
reverse_prerequisite_members (action a, target& t, bool members = true)
{
return prerequisite_members (
a, butl::reverse_iterate (t.prerequisites), members);
}
// prerequisite_members(group_prerequisites (t))
//
inline auto
group_prerequisite_members (action a, target& t, bool members = true)
{
return prerequisite_members (a, group_prerequisites (t), members);
}
// prerequisite_members(reverse_iterate (group_prerequisites (t)))
//
inline auto
reverse_group_prerequisite_members (action a, target& t, bool members = true)
{
return prerequisite_members (
a, butl::reverse_iterate (group_prerequisites (t)), members);
}
//
//
struct target_set
{
typedef std::map<target_key, std::unique_ptr<target>> map;
typedef butl::map_iterator_adapter<map::const_iterator> iterator;
iterator
find (const target_key& k, tracer& trace) const;
iterator
find (const target_type& type,
const dir_path& dir,
const std::string& name,
const std::string* ext,
tracer& trace) const
{
return find (target_key {&type, &dir, &name, &ext}, trace);
}
// As above but ignore the extension and return the target or
// nullptr instead of the iterator.
//
template <typename T>
T*
find (const dir_path& dir, const std::string& name) const
{
const std::string* e (nullptr);
auto i (map_.find (target_key {&T::static_type, &dir, &name, &e}));
return i != map_.end () ? static_cast<T*> (i->second.get ()) : nullptr;
}
iterator begin () const {return map_.begin ();}
iterator end () const {return map_.end ();}
std::pair<target&, bool>
insert (const target_type&,
dir_path dir,
std::string name,
const std::string* ext,
tracer&);
template <typename T>
T&
insert (const dir_path& dir,
const std::string& name,
const std::string* ext,
tracer& t)
{
return static_cast<T&> (
insert (T::static_type, dir, name, ext, t).first);
}
template <typename T>
T&
insert (const dir_path& dir, const std::string& name, tracer& t)
{
return static_cast<T&> (
insert (T::static_type, dir, name, nullptr, t).first);
}
void
clear () {map_.clear ();}
private:
map map_;
};
extern target_set targets;
// Modification time-based target.
//
class mtime_target: public target
{
public:
using target::target;
// Generally, modification time for a target can only be queried
// after a rule has been matched since that's where the path is
// normally gets assigned. Normally, however, it would make sense
// to first execute the rule to get the "updated" timestamp.
//
// The rule for groups that utilize the group state is as follows:
// if it has any members that are mtime_targets, then the group
// should be mtime_target and the members get the mtime from it.
//
timestamp
mtime () const
{
const mtime_target* t (raw_state == target_state::group
? static_cast<const mtime_target*> (group)
: this);
if (t->mtime_ == timestamp_unknown)
t->mtime_ = t->load_mtime ();
return t->mtime_;
}
void
mtime (timestamp mt)
{
// While we can cache the mtime at any time, it may be ignored
// if the target state is group (see the mtime() accessor).
//
mtime_ = mt;
}
protected:
virtual timestamp
load_mtime () const = 0;
public:
static const target_type static_type;
private:
mutable timestamp mtime_ {timestamp_unknown};
};
// Filesystem path-based target.
//
class path_target: public mtime_target
{
public:
using mtime_target::mtime_target;
typedef build::path path_type;
const path_type&
path () const {return path_;}
void
path (path_type p) {assert (path_.empty ()); path_ = std::move (p);}
// Derive a path from target's dir, name, and, if specified, ext.
// If ext is not specified, then use default_ext and also update
// the target's extension (this becomes important if later we need
// to reliably determine whether this file has an extension; think
// hxx{foo.bar.} and hxx.ext is empty).
//
// If name_prefix is not NULL, add it before the name part and after
// the directory. Similarly, if name_suffix is not NULL, add it after
// the name part and before the extension.
//
// Finally, if the path was already assigned to this target, then
// this function verifies that the two are the same.
//
void
derive_path (const char* default_ext = nullptr,
const char* name_prefix = nullptr,
const char* name_suffix = nullptr);
public:
static const target_type static_type;
private:
path_type path_;
};
// File target.
//
class file: public path_target
{
public:
using path_target::path_target;
protected:
// Note that it is final in order to be consistent with file_rule,
// search_existing_file().
//
virtual timestamp
load_mtime () const final;
public:
static const target_type static_type;
virtual const target_type& dynamic_type () const {return static_type;}
};
// Alias target. It represents a list of targets (its prerequisites)
// as a single "name".
//
class alias: public target
{
public:
using target::target;
public:
static const target_type static_type;
virtual const target_type& dynamic_type () const {return static_type;}
};
// Directory target. Note that this is not a filesystem directory
// but rather an alias target with the directory name. For actual
// filesystem directory (creation), see fsdir.
//
class dir: public alias
{
public:
using alias::alias;
public:
static const target_type static_type;
virtual const target_type& dynamic_type () const {return static_type;}
};
// While a filesystem directory is mtime-based, the semantics is
// not very useful in our case. In particular, if another target
// depends on fsdir{}, then all that's desired is the creation of
// the directory if it doesn't already exist. In particular, we
// don't want to update the target just because some unrelated
// entry was created in that directory.
//
class fsdir: public target
{
public:
using target::target;
public:
static const target_type static_type;
virtual const target_type& dynamic_type () const {return static_type;}
};
class buildfile: public file
{
public:
using file::file;
public:
static const target_type static_type;
virtual const target_type& dynamic_type () const {return static_type;}
};
// Common documentation file targets.
//
// @@ Maybe these should be in the built-in doc module?
//
class doc: public file
{
public:
using file::file;
public:
static const target_type static_type;
virtual const target_type& dynamic_type () const {return static_type;}
};
// The problem with man pages is this: different platforms have
// different sets of sections. What seems to be the "sane" set
// is 1-9 (Linux and BSDs). SysV (e.g., Solaris) instead maps
// 8 to 1M (system administration). The section determines two
// things: the directory where the page is installed (e.g.,
// /usr/share/man/man1) as well as the extension of the file
// (e.g., test.1). Note also that there could be sub-sections,
// e.g., 1p (for POSIX). Such a page would still go into man1
// but will have the .1p extension (at least that's what happens
// on Linux). The challenge is to somehow handle this in a
// portable manner. So here is the plan:
//
// First of all, we have the man{} target type which can be used
// for a custom man page. That is, you can have any extension and
// install it anywhere you please:
//
// man{foo.X}: install = man/manX
//
// Then we have man1..9{} target types which model the "sane"
// section set and that would be automatically installed into
// correct locations on other platforms. In other words, the
// idea is that you should be able to have the foo.8 file,
// write man8{foo} and have it installed as man1m/foo.1m on
// some SysV host.
//
// Re-mapping the installation directory is easy: to help with
// that we have assigned install.man1..9 directory names. The
// messy part is to change the extension. It seems the only
// way to do that would be to have special logic for man pages
// in the generic install rule. @@ This is still a TODO.
//
// Note that handling subsections with man1..9{} is easy, we
// simply specify the extension explicitly, e.g., man{foo.1p}.
//
class man: public doc
{
public:
using doc::doc;
public:
static const target_type static_type;
virtual const target_type& dynamic_type () const {return static_type;}
};
class man1: public man
{
public:
using man::man;
public:
static const target_type static_type;
virtual const target_type& dynamic_type () const {return static_type;}
};
// Common implementation of the target factory, extension, and
// search functions.
//
template <typename T>
target*
target_factory (const target_type&, dir_path d, string n, const string* e)
{
return new T (move (d), move (n), e);
}
// Return fixed target extension.
//
template <const char* ext>
const std::string&
target_extension_fix (const target_key&, scope&);
// Get the extension from the variable or use the default if none set.
// Issue diagnostics and fail if the default is NULL.
//
template <const char* var, const char* def>
const std::string&
target_extension_var (const target_key&, scope&);
// The default behavior, that is, look for an existing target in the
// prerequisite's directory scope.
//
target*
search_target (const prerequisite_key&);
// First look for an existing target as above. If not found, then look
// for an existing file in the target-type-specific list of paths.
//
target*
search_file (const prerequisite_key&);
}
#include <build/target.ixx>
#include <build/target.txx>
#endif // BUILD_TARGET
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