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+// file : libbuild2/cc/link-rule.cxx -*- C++ -*-
+// copyright : Copyright (c) 2014-2019 Code Synthesis Ltd
+// license : MIT; see accompanying LICENSE file
+
+#include <libbuild2/cc/link-rule.hxx>
+
+#include <map>
+#include <cstdlib> // exit()
+#include <cstring> // strlen()
+
+#include <libbutl/filesystem.mxx> // file_exists()
+
+#include <libbuild2/depdb.hxx>
+#include <libbuild2/scope.hxx>
+#include <libbuild2/context.hxx>
+#include <libbuild2/variable.hxx>
+#include <libbuild2/algorithm.hxx>
+#include <libbuild2/filesystem.hxx>
+#include <libbuild2/diagnostics.hxx>
+
+#include <libbuild2/bin/target.hxx>
+
+#include <libbuild2/cc/target.hxx> // c, pc*
+#include <libbuild2/cc/utility.hxx>
+
+using std::map;
+using std::exit;
+
+using namespace butl;
+
+namespace build2
+{
+ namespace cc
+ {
+ using namespace bin;
+
+ link_rule::
+ link_rule (data&& d)
+ : common (move (d)),
+ rule_id (string (x) += ".link 1")
+ {
+ static_assert (sizeof (match_data) <= target::data_size,
+ "insufficient space");
+ }
+
+ link_rule::match_result link_rule::
+ match (action a,
+ const target& t,
+ const target* g,
+ otype ot,
+ bool library) const
+ {
+ // NOTE: the target may be a group (see utility library logic below).
+
+ match_result r;
+
+ // Scan prerequisites and see if we can work with what we've got. Note
+ // that X could be C (as in language). We handle this by always checking
+ // for X first.
+ //
+ // Note also that we treat bmi{} as obj{}. @@ MODHDR hbmi{}?
+ //
+ for (prerequisite_member p:
+ prerequisite_members (a, t, group_prerequisites (t, g)))
+ {
+ // If excluded or ad hoc, then don't factor it into our tests.
+ //
+ if (include (a, t, p) != include_type::normal)
+ continue;
+
+ if (p.is_a (x_src) ||
+ (x_mod != nullptr && p.is_a (*x_mod)) ||
+ // Header-only X library (or library with C source and X header).
+ (library && x_header (p, false /* c_hdr */)))
+ {
+ r.seen_x = r.seen_x || true;
+ }
+ else if (p.is_a<c> () ||
+ // Header-only C library.
+ (library && p.is_a<h> ()))
+ {
+ r.seen_c = r.seen_c || true;
+ }
+ else if (p.is_a<obj> () || p.is_a<bmi> ())
+ {
+ r.seen_obj = r.seen_obj || true;
+ }
+ else if (p.is_a<obje> () || p.is_a<bmie> ())
+ {
+ // We can make these "no-match" if/when there is a valid use case.
+ //
+ if (ot != otype::e)
+ fail << p.type ().name << "{} as prerequisite of " << t;
+
+ r.seen_obj = r.seen_obj || true;
+ }
+ else if (p.is_a<obja> () || p.is_a<bmia> ())
+ {
+ if (ot != otype::a)
+ fail << p.type ().name << "{} as prerequisite of " << t;
+
+ r.seen_obj = r.seen_obj || true;
+ }
+ else if (p.is_a<objs> () || p.is_a<bmis> ())
+ {
+ if (ot != otype::s)
+ fail << p.type ().name << "{} as prerequisite of " << t;
+
+ r.seen_obj = r.seen_obj || true;
+ }
+ else if (p.is_a<libul> () || p.is_a<libux> ())
+ {
+ // For a unility library we look at its prerequisites, recursively.
+ // Since these checks are not exactly light-weight, only do them if
+ // we haven't already seen any X prerequisites.
+ //
+ if (!r.seen_x)
+ {
+ // This is a bit iffy: in our model a rule can only search a
+ // target's prerequisites if it matches. But we don't yet know
+ // whether we match. However, it seems correct to assume that any
+ // rule-specific search will always resolve to an existing target
+ // if there is one. So perhaps it's time to relax this restriction
+ // a little? Note that this fits particularly well with what we
+ // doing here since if there is no existing target, then there can
+ // be no prerequisites.
+ //
+ // Note, however, that we cannot linkup a prerequisite target
+ // member to its group since we are not matching this target. As
+ // result we have to do all the steps except for setting t.group
+ // and pass both member and group (we also cannot query t.group
+ // since it's racy).
+ //
+ const target* pg (nullptr);
+ const target* pt (p.search_existing ());
+
+ if (p.is_a<libul> ())
+ {
+ if (pt != nullptr)
+ {
+ // If this is a group then try to pick (again, if exists) a
+ // suitable member. If it doesn't exist, then we will only be
+ // considering the group's prerequisites.
+ //
+ if (const target* pm =
+ link_member (pt->as<libul> (),
+ a,
+ linfo {ot, lorder::a /* unused */},
+ true /* existing */))
+ {
+ pg = pt;
+ pt = pm;
+ }
+ }
+ else
+ {
+ // It's possible we have no group but have a member so try
+ // that.
+ //
+ const target_type& tt (ot == otype::a ? libua::static_type :
+ ot == otype::s ? libus::static_type :
+ libue::static_type);
+
+ // We know this prerequisite member is a prerequisite since
+ // otherwise the above search would have returned the member
+ // target.
+ //
+ pt = search_existing (t.ctx, p.prerequisite.key (tt));
+ }
+ }
+ else if (!p.is_a<libue> ())
+ {
+ // See if we also/instead have a group.
+ //
+ pg = search_existing (t.ctx,
+ p.prerequisite.key (libul::static_type));
+
+ if (pt == nullptr)
+ swap (pt, pg);
+ }
+
+ if (pt != nullptr)
+ {
+ // If we are matching a target, use the original output type
+ // since that would be the member that we pick.
+ //
+ otype pot (pt->is_a<libul> () ? ot : link_type (*pt).type);
+ match_result pr (match (a, *pt, pg, pot, true /* lib */));
+
+ // Do we need to propagate any other seen_* values? Hm, that
+ // would in fact match with the "see-through" semantics of
+ // utility libraries we have in other places.
+ //
+ r.seen_x = pr.seen_x;
+ }
+ else
+ r.seen_lib = r.seen_lib || true; // Consider as just a library.
+ }
+ }
+ else if (p.is_a<lib> () ||
+ p.is_a<liba> () ||
+ p.is_a<libs> ())
+ {
+ r.seen_lib = r.seen_lib || true;
+ }
+ // Some other c-common header/source (say C++ in a C rule) other than
+ // a C header (we assume everyone can hanle that).
+ //
+ else if (p.is_a<cc> () && !(x_header (p, true /* c_hdr */)))
+ {
+ r.seen_cc = true;
+ break;
+ }
+ }
+
+ return r;
+ }
+
+ bool link_rule::
+ match (action a, target& t, const string& hint) const
+ {
+ // NOTE: may be called multiple times and for both inner and outer
+ // operations (see the install rules).
+
+ tracer trace (x, "link_rule::match");
+
+ ltype lt (link_type (t));
+
+ // If this is a group member library, link-up to our group (this is the
+ // target group protocol which means this can be done whether we match
+ // or not).
+ //
+ // If we are called for the outer operation (see install rules), then
+ // use resolve_group() to delegate to inner.
+ //
+ if (lt.member_library ())
+ {
+ if (a.outer ())
+ resolve_group (a, t);
+ else if (t.group == nullptr)
+ t.group = &search (t,
+ lt.utility ? libul::static_type : lib::static_type,
+ t.dir, t.out, t.name);
+ }
+
+ match_result r (match (a, t, t.group, lt.type, lt.library ()));
+
+ // If this is some other c-common header/source (say C++ in a C rule),
+ // then we shouldn't try to handle that (it may need to be compiled,
+ // etc).
+ //
+ if (r.seen_cc)
+ {
+ l4 ([&]{trace << "non-" << x_lang << " prerequisite "
+ << "for target " << t;});
+ return false;
+ }
+
+ if (!(r.seen_x || r.seen_c || r.seen_obj || r.seen_lib))
+ {
+ l4 ([&]{trace << "no " << x_lang << ", C, or obj/lib prerequisite "
+ << "for target " << t;});
+ return false;
+ }
+
+ // We will only chain a C source if there is also an X source or we were
+ // explicitly told to.
+ //
+ if (r.seen_c && !r.seen_x && hint < x)
+ {
+ l4 ([&]{trace << "C prerequisite without " << x_lang << " or hint "
+ << "for target " << t;});
+ return false;
+ }
+
+ return true;
+ }
+
+ auto link_rule::
+ derive_libs_paths (file& t,
+ const char* pfx,
+ const char* sfx) const -> libs_paths
+ {
+ bool win (tclass == "windows");
+
+ // Get default prefix and extension.
+ //
+ const char* ext (nullptr);
+ if (win)
+ {
+ if (tsys == "mingw32")
+ {
+ if (pfx == nullptr)
+ pfx = "lib";
+ }
+
+ ext = "dll";
+ }
+ else
+ {
+ if (pfx == nullptr)
+ pfx = "lib";
+
+ if (tclass == "macos")
+ ext = "dylib";
+ else
+ ext = "so";
+ }
+
+ // First sort out which extension we are using.
+ //
+ const string& e (t.derive_extension (ext));
+
+ auto append_ext = [&e] (path& p)
+ {
+ if (!e.empty ())
+ {
+ p += '.';
+ p += e;
+ }
+ };
+
+ // See if we have the load suffix.
+ //
+ const string& ls (cast_empty<string> (t["bin.lib.load_suffix"]));
+
+ // Figure out the version.
+ //
+ string ver;
+ using verion_map = map<string, string>;
+ if (const verion_map* m = cast_null<verion_map> (t["bin.lib.version"]))
+ {
+ // First look for the target system.
+ //
+ auto i (m->find (tsys));
+
+ // Then look for the target class.
+ //
+ if (i == m->end ())
+ i = m->find (tclass);
+
+ // Then look for the wildcard. Since it is higly unlikely one can have
+ // a version that will work across platforms, this is only useful to
+ // say "all others -- no version".
+ //
+ if (i == m->end ())
+ i = m->find ("*");
+
+ // At this stage the only platform-specific version we support is the
+ // "no version" override.
+ //
+ if (i != m->end () && !i->second.empty ())
+ fail << i->first << "-specific bin.lib.version not yet supported";
+
+ // Finally look for the platform-independent version.
+ //
+ if (i == m->end ())
+ i = m->find ("");
+
+ // If we didn't find anything, fail. If the bin.lib.version was
+ // specified, then it should explicitly handle all the targets.
+ //
+ if (i == m->end ())
+ fail << "no version for " << ctgt << " in bin.lib.version" <<
+ info << "considere adding " << tsys << "@<ver> or " << tclass
+ << "@<ver>";
+
+ ver = i->second;
+ }
+
+ // Now determine the paths.
+ //
+ path lk, ld, so, in;
+
+ // We start with the basic path.
+ //
+ path b (t.dir);
+
+ if (pfx != nullptr && pfx[0] != '\0')
+ {
+ b /= pfx;
+ b += t.name;
+ }
+ else
+ b /= t.name;
+
+ if (sfx != nullptr && sfx[0] != '\0')
+ b += sfx;
+
+ // Clean pattern.
+ //
+ path cp (b);
+ cp += "?*"; // Don't match empty (like the libfoo.so symlink).
+ append_ext (cp);
+
+ // On Windows the real path is to libs{} and the link path is empty.
+ // Note that we still need to derive the import library path.
+ //
+ if (win)
+ {
+ // Usually on Windows with MSVC the import library is called the same
+ // as the DLL but with the .lib extension. Which means it clashes with
+ // the static library. Instead of decorating the static library name
+ // with ugly suffixes (as is customary), let's use the MinGW approach
+ // (one must admit it's quite elegant) and call it .dll.lib.
+ //
+ libi& i (*find_adhoc_member<libi> (t));
+
+ if (i.path ().empty ())
+ {
+ path ip (b);
+ append_ext (ip);
+ i.derive_path (move (ip), tsys == "mingw32" ? "a" : "lib");
+ }
+ }
+ // We will only need the link name if the following name differs.
+ //
+ else if (!ver.empty () || !ls.empty ())
+ {
+ lk = b;
+ append_ext (lk);
+ }
+
+ // See if we have the load suffix.
+ //
+ if (!ls.empty ())
+ {
+ b += ls;
+
+ // We will only need the load name if the following name differs.
+ //
+ if (!ver.empty ())
+ {
+ ld = b;
+ append_ext (ld);
+ }
+ }
+
+ if (!ver.empty ())
+ b += ver;
+
+ const path& re (t.derive_path (move (b)));
+
+ return libs_paths {
+ move (lk), move (ld), move (so), move (in), &re, move (cp)};
+ }
+
+ // Look for binary-full utility library recursively until we hit a
+ // non-utility "barier".
+ //
+ static bool
+ find_binfull (action a, const target& t, linfo li)
+ {
+ for (const target* pt: t.prerequisite_targets[a])
+ {
+ if (pt == nullptr || unmark (pt) != 0) // Called after pass 1 below.
+ continue;
+
+ const file* pf;
+
+ // If this is the libu*{} group, then pick the appropriate member.
+ //
+ if (const libul* ul = pt->is_a<libul> ())
+ {
+ pf = &link_member (*ul, a, li)->as<file> ();
+ }
+ else if ((pf = pt->is_a<libue> ()) ||
+ (pf = pt->is_a<libus> ()) ||
+ (pf = pt->is_a<libua> ()))
+ ;
+ else
+ continue;
+
+ if (!pf->path ().empty () || find_binfull (a, *pf, li))
+ return true;
+ }
+
+ return false;
+ };
+
+ recipe link_rule::
+ apply (action a, target& xt) const
+ {
+ tracer trace (x, "link_rule::apply");
+
+ file& t (xt.as<file> ());
+ context& ctx (t.ctx);
+
+ // Note that for_install is signalled by install_rule and therefore
+ // can only be relied upon during execute.
+ //
+ match_data& md (t.data (match_data ()));
+
+ const scope& bs (t.base_scope ());
+ const scope& rs (*bs.root_scope ());
+
+ ltype lt (link_type (t));
+ otype ot (lt.type);
+ linfo li (link_info (bs, ot));
+
+ // Set the library type (C, C++, etc) as rule-specific variable.
+ //
+ if (lt.library ())
+ t.state[a].assign (c_type) = string (x);
+
+ bool binless (lt.library ()); // Binary-less until proven otherwise.
+
+ // Inject dependency on the output directory. Note that we do it even
+ // for binless libraries since there could be other output (e.g., .pc
+ // files).
+ //
+ inject_fsdir (a, t);
+
+ // Process prerequisites, pass 1: search and match prerequisite
+ // libraries, search obj/bmi{} targets, and search targets we do rule
+ // chaining for.
+ //
+ // Also clear the binless flag if we see any source or object files.
+ // Note that if we don't see any this still doesn't mean the library is
+ // binless since it can depend on a binfull utility library. This we
+ // check below, after matching the libraries.
+ //
+ // We do libraries first in order to indicate that we will execute these
+ // targets before matching any of the obj/bmi{}. This makes it safe for
+ // compile::apply() to unmatch them and therefore not to hinder
+ // parallelism.
+ //
+ // We also create obj/bmi{} chain targets because we need to add
+ // (similar to lib{}) all the bmi{} as prerequisites to all the other
+ // obj/bmi{} that we are creating. Note that this doesn't mean that the
+ // compile rule will actually treat them all as prerequisite targets.
+ // Rather, they are used to resolve actual module imports. We don't
+ // really have to search obj{} targets here but it's the same code so we
+ // do it here to avoid duplication.
+ //
+ // Also, when cleaning, we ignore prerequisites that are not in the same
+ // or a subdirectory of our project root. Except for libraries: if we
+ // ignore them, then they won't be added to synthesized dependencies and
+ // this will break things if we do, say, update after clean in the same
+ // invocation. So for libraries we ignore them later, on pass 3.
+ //
+ optional<dir_paths> usr_lib_dirs; // Extract lazily.
+ compile_target_types tts (compile_types (ot));
+
+ auto skip = [&a, &rs] (const target* pt) -> bool
+ {
+ return a.operation () == clean_id && !pt->dir.sub (rs.out_path ());
+ };
+
+ auto& pts (t.prerequisite_targets[a]);
+ size_t start (pts.size ());
+
+ for (prerequisite_member p: group_prerequisite_members (a, t))
+ {
+ include_type pi (include (a, t, p));
+
+ // We pre-allocate a NULL slot for each (potential; see clean)
+ // prerequisite target.
+ //
+ pts.push_back (prerequisite_target (nullptr, pi));
+ const target*& pt (pts.back ());
+
+ if (pi != include_type::normal) // Skip excluded and ad hoc.
+ continue;
+
+ // Mark:
+ // 0 - lib
+ // 1 - src
+ // 2 - mod
+ // 3 - obj/bmi and also lib not to be cleaned
+ //
+ uint8_t m (0);
+
+ bool mod (x_mod != nullptr && p.is_a (*x_mod));
+
+ if (mod || p.is_a (x_src) || p.is_a<c> ())
+ {
+ binless = binless && false;
+
+ // Rule chaining, part 1.
+ //
+
+ // Which scope shall we use to resolve the root? Unlikely, but
+ // possible, the prerequisite is from a different project
+ // altogether. So we are going to use the target's project.
+ //
+
+ // If the source came from the lib{} group, then create the obj{}
+ // group and add the source as a prerequisite of the obj{} group,
+ // not the obj*{} member. This way we only need one prerequisite
+ // for, say, both liba{} and libs{}. The same goes for bmi{}.
+ //
+ bool group (!p.prerequisite.belongs (t)); // Group's prerequisite.
+
+ const target_type& rtt (mod
+ ? (group ? bmi::static_type : tts.bmi)
+ : (group ? obj::static_type : tts.obj));
+
+ const prerequisite_key& cp (p.key ()); // Source key.
+
+ // Come up with the obj*/bmi*{} target. The source prerequisite
+ // directory can be relative (to the scope) or absolute. If it is
+ // relative, then use it as is. If absolute, then translate it to
+ // the corresponding directory under out_root. While the source
+ // directory is most likely under src_root, it is also possible it
+ // is under out_root (e.g., generated source).
+ //
+ dir_path d;
+ {
+ const dir_path& cpd (*cp.tk.dir);
+
+ if (cpd.relative () || cpd.sub (rs.out_path ()))
+ d = cpd;
+ else
+ {
+ if (!cpd.sub (rs.src_path ()))
+ fail << "out of project prerequisite " << cp <<
+ info << "specify corresponding " << rtt.name << "{} "
+ << "target explicitly";
+
+ d = rs.out_path () / cpd.leaf (rs.src_path ());
+ }
+ }
+
+ // obj/bmi{} is always in the out tree. Note that currently it could
+ // be the group -- we will pick a member in part 2 below.
+ //
+ pt = &search (t, rtt, d, dir_path (), *cp.tk.name, nullptr, cp.scope);
+
+ // If we shouldn't clean obj{}, then it is fair to assume we
+ // shouldn't clean the source either (generated source will be in
+ // the same directory as obj{} and if not, well, go find yourself
+ // another build system ;-)).
+ //
+ if (skip (pt))
+ {
+ pt = nullptr;
+ continue;
+ }
+
+ m = mod ? 2 : 1;
+ }
+ else if (p.is_a<libx> () ||
+ p.is_a<liba> () ||
+ p.is_a<libs> () ||
+ p.is_a<libux> ())
+ {
+ // Handle imported libraries.
+ //
+ // Note that since the search is rule-specific, we don't cache the
+ // target in the prerequisite.
+ //
+ if (p.proj ())
+ pt = search_library (
+ a, sys_lib_dirs, usr_lib_dirs, p.prerequisite);
+
+ // The rest is the same basic logic as in search_and_match().
+ //
+ if (pt == nullptr)
+ pt = &p.search (t);
+
+ if (skip (pt))
+ m = 3; // Mark so it is not matched.
+
+ // If this is the lib{}/libu{} group, then pick the appropriate
+ // member.
+ //
+ if (const libx* l = pt->is_a<libx> ())
+ pt = link_member (*l, a, li);
+ }
+ else
+ {
+ // If this is the obj{} or bmi{} target group, then pick the
+ // appropriate member.
+ //
+ if (p.is_a<obj> ()) pt = &search (t, tts.obj, p.key ());
+ else if (p.is_a<bmi> ()) pt = &search (t, tts.bmi, p.key ());
+ //
+ // Windows module definition (.def). For other platforms (and for
+ // static libraries) treat it as an ordinary prerequisite.
+ //
+ else if (p.is_a<def> () && tclass == "windows" && ot != otype::a)
+ {
+ pt = &p.search (t);
+ }
+ //
+ // Something else. This could be something unrelated that the user
+ // tacked on (e.g., a doc{}). Or it could be some ad hoc input to
+ // the linker (say a linker script or some such).
+ //
+ else
+ {
+ if (!p.is_a<objx> () && !p.is_a<bmix> ())
+ {
+ // @@ Temporary hack until we get the default outer operation
+ // for update. This allows operations like test and install to
+ // skip such tacked on stuff.
+ //
+ // Note that ad hoc inputs have to be explicitly marked with the
+ // include=adhoc prerequisite-specific variable.
+ //
+ if (ctx.current_outer_oif != nullptr)
+ continue;
+ }
+
+ pt = &p.search (t);
+ }
+
+ if (skip (pt))
+ {
+ pt = nullptr;
+ continue;
+ }
+
+ // @@ MODHDR: hbmix{} has no objx{}
+ //
+ binless = binless && !(pt->is_a<objx> () || pt->is_a<bmix> ());
+
+ m = 3;
+ }
+
+ mark (pt, m);
+ }
+
+ // Match lib{} (the only unmarked) in parallel and wait for completion.
+ //
+ match_members (a, t, pts, start);
+
+ // Check if we have any binfull utility libraries.
+ //
+ binless = binless && !find_binfull (a, t, li);
+
+ // Now that we know for sure whether we are binless, derive file name(s)
+ // and add ad hoc group members. Note that for binless we still need the
+ // .pc member (whose name depends on the libray prefix) so we take care
+ // to not derive the path for the library target itself inside.
+ //
+ {
+ const char* e (nullptr); // Extension.
+ const char* p (nullptr); // Prefix.
+ const char* s (nullptr); // Suffix.
+
+ if (lt.utility)
+ {
+ // These are all static libraries with names indicating the kind of
+ // object files they contain (similar to how we name object files
+ // themselves). We add the 'u' extension to avoid clashes with
+ // real libraries/import stubs.
+ //
+ // libue libhello.u.a hello.exe.u.lib
+ // libua libhello.a.u.a hello.lib.u.lib
+ // libus libhello.so.u.a hello.dll.u.lib hello.dylib.u.lib
+ //
+ // Note that we currently don't add bin.lib.{prefix,suffix} since
+ // these are not installed.
+ //
+ if (tsys == "win32-msvc")
+ {
+ switch (ot)
+ {
+ case otype::e: e = "exe.u.lib"; break;
+ case otype::a: e = "lib.u.lib"; break;
+ case otype::s: e = "dll.u.lib"; break;
+ }
+ }
+ else
+ {
+ p = "lib";
+
+ if (tsys == "mingw32")
+ {
+ switch (ot)
+ {
+ case otype::e: e = "exe.u.a"; break;
+ case otype::a: e = "a.u.a"; break;
+ case otype::s: e = "dll.u.a"; break;
+ }
+
+ }
+ else if (tsys == "darwin")
+ {
+ switch (ot)
+ {
+ case otype::e: e = "u.a"; break;
+ case otype::a: e = "a.u.a"; break;
+ case otype::s: e = "dylib.u.a"; break;
+ }
+ }
+ else
+ {
+ switch (ot)
+ {
+ case otype::e: e = "u.a"; break;
+ case otype::a: e = "a.u.a"; break;
+ case otype::s: e = "so.u.a"; break;
+ }
+ }
+ }
+
+ if (binless)
+ t.path (empty_path);
+ else
+ t.derive_path (e, p, s);
+ }
+ else
+ {
+ if (auto l = t[ot == otype::e ? "bin.exe.prefix" : "bin.lib.prefix"])
+ p = cast<string> (l).c_str ();
+ if (auto l = t[ot == otype::e ? "bin.exe.suffix" : "bin.lib.suffix"])
+ s = cast<string> (l).c_str ();
+
+ switch (ot)
+ {
+ case otype::e:
+ {
+ if (tclass == "windows")
+ e = "exe";
+ else
+ e = "";
+
+ t.derive_path (e, p, s);
+ break;
+ }
+ case otype::a:
+ {
+ if (tsys == "win32-msvc")
+ e = "lib";
+ else
+ {
+ if (p == nullptr) p = "lib";
+ e = "a";
+ }
+
+ if (binless)
+ t.path (empty_path);
+ else
+ t.derive_path (e, p, s);
+
+ break;
+ }
+ case otype::s:
+ {
+ if (binless)
+ t.path (empty_path);
+ else
+ {
+ // On Windows libs{} is an ad hoc group. The libs{} itself is
+ // the DLL and we add libi{} import library as its member.
+ //
+ if (tclass == "windows")
+ {
+ e = "dll";
+ add_adhoc_member<libi> (t);
+ }
+
+ md.libs_paths = derive_libs_paths (t, p, s);
+ }
+
+ break;
+ }
+ }
+
+ // Add VC's .pdb. Note that we are looking for the link.exe /DEBUG
+ // option.
+ //
+ if (!binless && ot != otype::a && tsys == "win32-msvc")
+ {
+ if (find_option ("/DEBUG", t, c_loptions, true) ||
+ find_option ("/DEBUG", t, x_loptions, true))
+ {
+ const target_type& tt (*bs.find_target_type ("pdb"));
+
+ // We call the target foo.{exe,dll}.pdb rather than just foo.pdb
+ // because we can have both foo.exe and foo.dll in the same
+ // directory.
+ //
+ file& pdb (add_adhoc_member<file> (t, tt, e));
+
+ // Note that the path is derived from the exe/dll path (so it
+ // will include the version in case of a dll).
+ //
+ if (pdb.path ().empty ())
+ pdb.derive_path (t.path (), "pdb");
+ }
+ }
+
+ // Add pkg-config's .pc file.
+ //
+ // Note that we do it regardless of whether we are installing or not
+ // for two reasons. Firstly, it is not easy to detect this situation
+ // here since the for_install hasn't yet been communicated by
+ // install_rule. Secondly, always having this member takes care of
+ // cleanup automagically. The actual generation happens in
+ // perform_update() below.
+ //
+ if (ot != otype::e)
+ {
+ file& pc (add_adhoc_member<file> (t,
+ (ot == otype::a
+ ? pca::static_type
+ : pcs::static_type)));
+
+ // Note that here we always use the lib name prefix, even on
+ // Windows with VC. The reason is the user needs a consistent name
+ // across platforms by which they can refer to the library. This
+ // is also the reason why we use the .static and .shared second-
+ // level extensions rather that a./.lib and .so/.dylib/.dll.
+ //
+ if (pc.path ().empty ())
+ pc.derive_path (nullptr, (p == nullptr ? "lib" : p), s);
+ }
+
+ // Add the Windows rpath emulating assembly directory as fsdir{}.
+ //
+ // Currently this is used in the backlinking logic and in the future
+ // could also be used for clean (though there we may want to clean
+ // old assemblies).
+ //
+ if (ot == otype::e && tclass == "windows")
+ {
+ // Note that here we cannot determine whether we will actually
+ // need one (for_install, library timestamps are not available at
+ // this point to call windows_rpath_timestamp()). So we may add
+ // the ad hoc target but actually not produce the assembly. So
+ // whomever relies on this must check if the directory actually
+ // exists (windows_rpath_assembly() does take care to clean it up
+ // if not used).
+ //
+#ifdef _WIN32
+ target& dir =
+#endif
+ add_adhoc_member (t,
+ fsdir::static_type,
+ path_cast<dir_path> (t.path () + ".dlls"),
+ t.out,
+ string () /* name */);
+
+ // By default our backlinking logic will try to symlink the
+ // directory and it can even be done on Windows using junctions.
+ // The problem is the Windows DLL assembly "logic" refuses to
+ // recognize a junction as a valid assembly for some reason. So we
+ // are going to resort to copy-link (i.e., a real directory with a
+ // bunch of links).
+ //
+ // Interestingly, the directory symlink works just fine under
+ // Wine. So we only resort to copy-link'ing if we are running on
+ // Windows.
+ //
+#ifdef _WIN32
+ dir.state[a].assign (ctx.var_backlink) = "copy";
+#endif
+ }
+ }
+ }
+
+ // Process prerequisites, pass 2: finish rule chaining but don't start
+ // matching anything yet since that may trigger recursive matching of
+ // bmi{} targets we haven't completed yet. Hairy, I know.
+ //
+
+ // Parallel prerequisites/prerequisite_targets loop.
+ //
+ size_t i (start);
+ for (prerequisite_member p: group_prerequisite_members (a, t))
+ {
+ const target*& pt (pts[i].target);
+ uintptr_t& pd (pts[i++].data);
+
+ if (pt == nullptr)
+ continue;
+
+ // New mark:
+ // 1 - completion
+ // 2 - verification
+ //
+ uint8_t m (unmark (pt));
+
+ if (m == 3) // obj/bmi or lib not to be cleaned
+ {
+ m = 1; // Just completion.
+
+ // Note that if this is a library not to be cleaned, we keep it
+ // marked for completion (see the next phase).
+ }
+ else if (m == 1 || m == 2) // Source/module chain.
+ {
+ bool mod (m == 2);
+
+ m = 1;
+
+ const target& rt (*pt);
+ bool group (!p.prerequisite.belongs (t)); // Group's prerequisite.
+
+ // If we have created a obj/bmi{} target group, pick one of its
+ // members; the rest would be primarily concerned with it.
+ //
+ pt =
+ group
+ ? &search (t, (mod ? tts.bmi : tts.obj), rt.dir, rt.out, rt.name)
+ : &rt;
+
+ const target_type& rtt (mod
+ ? (group ? bmi::static_type : tts.bmi)
+ : (group ? obj::static_type : tts.obj));
+
+ // If this obj*{} already has prerequisites, then verify they are
+ // "compatible" with what we are doing here. Otherwise, synthesize
+ // the dependency. Note that we may also end up synthesizing with
+ // someone beating us to it. In this case also verify.
+ //
+ bool verify (true);
+
+ // Note that we cannot use has_group_prerequisites() since the
+ // target is not yet matched. So we check the group directly. Of
+ // course, all of this is racy (see below).
+ //
+ if (!pt->has_prerequisites () &&
+ (!group || !rt.has_prerequisites ()))
+ {
+ prerequisites ps {p.as_prerequisite ()}; // Source.
+
+ // Add our lib*{} (see the export.* machinery for details) and
+ // bmi*{} (both original and chained; see module search logic)
+ // prerequisites.
+ //
+ // Note that we don't resolve lib{} to liba{}/libs{} here
+ // instead leaving it to whomever (e.g., the compile rule) will
+ // be needing *.export.*. One reason for doing it there is that
+ // the object target might be specified explicitly by the user
+ // in which case they will have to specify the set of lib{}
+ // prerequisites and it's much cleaner to do as lib{} rather
+ // than liba{}/libs{}.
+ //
+ // Initially, we were only adding imported libraries, but there
+ // is a problem with this approach: the non-imported library
+ // might depend on the imported one(s) which we will never "see"
+ // unless we start with this library.
+ //
+ // Note: have similar logic in make_module_sidebuild().
+ //
+ size_t j (start);
+ for (prerequisite_member p: group_prerequisite_members (a, t))
+ {
+ const target* pt (pts[j++]);
+
+ if (pt == nullptr) // Note: ad hoc is taken care of.
+ continue;
+
+ // NOTE: pt may be marked (even for a library -- see clean
+ // above). So watch out for a faux pax in this careful dance.
+ //
+ if (p.is_a<libx> () ||
+ p.is_a<liba> () || p.is_a<libs> () || p.is_a<libux> () ||
+ p.is_a<bmi> () || p.is_a (tts.bmi))
+ {
+ ps.push_back (p.as_prerequisite ());
+ }
+ else if (x_mod != nullptr && p.is_a (*x_mod)) // Chained module.
+ {
+ // Searched during pass 1 but can be NULL or marked.
+ //
+ if (pt != nullptr && i != j) // Don't add self (note: both +1).
+ {
+ // This is sticky: pt might have come before us and if it
+ // was a group, then we would have picked up a member. So
+ // here we may have to "unpick" it.
+ //
+ bool group (j < i && !p.prerequisite.belongs (t));
+
+ unmark (pt);
+ ps.push_back (prerequisite (group ? *pt->group : *pt));
+ }
+ }
+ }
+
+ // Note: adding to the group, not the member.
+ //
+ verify = !rt.prerequisites (move (ps));
+
+ // Recheck that the target still has no prerequisites. If that's
+ // no longer the case, then verify the result is compatible with
+ // what we need.
+ //
+ // Note that there are scenarios where we will not detect this or
+ // the detection will be racy. For example, thread 1 adds the
+ // prerequisite to the group and then thread 2, which doesn't use
+ // the group, adds the prerequisite to the member. This could be
+ // triggered by something like this (undetectable):
+ //
+ // lib{foo}: cxx{foo}
+ // exe{foo}: cxx{foo}
+ //
+ // Or this (detection is racy):
+ //
+ // lib{bar}: cxx{foo}
+ // liba{baz}: cxx{foo}
+ //
+ // The current feeling, however, is that in non-contrived cases
+ // (i.e., the source file is the same) this should be harmless.
+ //
+ if (!verify && group)
+ verify = pt->has_prerequisites ();
+ }
+
+ if (verify)
+ {
+ // This gets a bit tricky. We need to make sure the source files
+ // are the same which we can only do by comparing the targets to
+ // which they resolve. But we cannot search ot's prerequisites --
+ // only the rule that matches can. Note, however, that if all this
+ // works out, then our next step is to match the obj*{} target. If
+ // things don't work out, then we fail, in which case searching
+ // and matching speculatively doesn't really hurt. So we start the
+ // async match here and finish this verification in the "harvest"
+ // loop below.
+ //
+ resolve_group (a, *pt); // Not matched yet so resolve group.
+
+ bool src (false);
+ for (prerequisite_member p1: group_prerequisite_members (a, *pt))
+ {
+ // Most of the time we will have just a single source so fast-
+ // path that case.
+ //
+ if (p1.is_a (mod ? *x_mod : x_src) || p1.is_a<c> ())
+ {
+ src = true;
+ continue; // Check the rest of the prerequisites.
+ }
+
+ // Ignore some known target types (fsdir, headers, libraries,
+ // modules).
+ //
+ if (p1.is_a<fsdir> () ||
+ p1.is_a<libx> () ||
+ p1.is_a<liba> () || p1.is_a<libs> () || p1.is_a<libux> () ||
+ p1.is_a<bmi> () || p1.is_a<bmix> () ||
+ (p.is_a (mod ? *x_mod : x_src) && x_header (p1)) ||
+ (p.is_a<c> () && p1.is_a<h> ()))
+ continue;
+
+ fail << "synthesized dependency for prerequisite " << p
+ << " would be incompatible with existing target " << *pt <<
+ info << "unexpected existing prerequisite type " << p1 <<
+ info << "specify corresponding " << rtt.name << "{} "
+ << "dependency explicitly";
+ }
+
+ if (!src)
+ fail << "synthesized dependency for prerequisite " << p
+ << " would be incompatible with existing target " << *pt <<
+ info << "no existing c/" << x_name << " source prerequisite" <<
+ info << "specify corresponding " << rtt.name << "{} "
+ << "dependency explicitly";
+
+ m = 2; // Needs verification.
+ }
+ }
+ else // lib*{}
+ {
+ // If this is a static library, see if we need to link it whole.
+ // Note that we have to do it after match since we rely on the
+ // group link-up.
+ //
+ bool u;
+ if ((u = pt->is_a<libux> ()) || pt->is_a<liba> ())
+ {
+ const variable& var (ctx.var_pool["bin.whole"]); // @@ Cache.
+
+ // See the bin module for the lookup semantics discussion. Note
+ // that the variable is not overridable so we omit find_override()
+ // calls.
+ //
+ lookup l (p.prerequisite.vars[var]);
+
+ if (!l.defined ())
+ l = pt->find_original (var, true).first;
+
+ if (!l.defined ())
+ {
+ bool g (pt->group != nullptr);
+ l = bs.find_original (var,
+ &pt->type (),
+ &pt->name,
+ (g ? &pt->group->type () : nullptr),
+ (g ? &pt->group->name : nullptr)).first;
+ }
+
+ if (l ? cast<bool> (*l) : u)
+ pd |= lflag_whole;
+ }
+ }
+
+ mark (pt, m);
+ }
+
+ // Process prerequisites, pass 3: match everything and verify chains.
+ //
+
+ // Wait with unlocked phase to allow phase switching.
+ //
+ wait_guard wg (ctx, ctx.count_busy (), t[a].task_count, true);
+
+ i = start;
+ for (prerequisite_member p: group_prerequisite_members (a, t))
+ {
+ bool adhoc (pts[i].adhoc);
+ const target*& pt (pts[i++]);
+
+ uint8_t m;
+
+ if (pt == nullptr)
+ {
+ // Handle ad hoc prerequisities.
+ //
+ if (!adhoc)
+ continue;
+
+ pt = &p.search (t);
+ m = 1; // Mark for completion.
+ }
+ else if ((m = unmark (pt)) != 0)
+ {
+ // If this is a library not to be cleaned, we can finally blank it
+ // out.
+ //
+ if (skip (pt))
+ {
+ pt = nullptr;
+ continue;
+ }
+ }
+
+ match_async (a, *pt, ctx.count_busy (), t[a].task_count);
+ mark (pt, m);
+ }
+
+ wg.wait ();
+
+ // The "harvest" loop: finish matching the targets we have started. Note
+ // that we may have bailed out early (thus the parallel i/n for-loop).
+ //
+ i = start;
+ for (prerequisite_member p: group_prerequisite_members (a, t))
+ {
+ const target*& pt (pts[i++]);
+
+ // Skipped or not marked for completion.
+ //
+ uint8_t m;
+ if (pt == nullptr || (m = unmark (pt)) == 0)
+ continue;
+
+ build2::match (a, *pt);
+
+ // Nothing else to do if not marked for verification.
+ //
+ if (m == 1)
+ continue;
+
+ // Finish verifying the existing dependency (which is now matched)
+ // compared to what we would have synthesized.
+ //
+ bool mod (x_mod != nullptr && p.is_a (*x_mod));
+
+ // Note: group already resolved in the previous loop.
+
+ for (prerequisite_member p1: group_prerequisite_members (a, *pt))
+ {
+ if (p1.is_a (mod ? *x_mod : x_src) || p1.is_a<c> ())
+ {
+ // Searching our own prerequisite is ok, p1 must already be
+ // resolved.
+ //
+ const target& tp (p.search (t));
+ const target& tp1 (p1.search (*pt));
+
+ if (&tp != &tp1)
+ {
+ bool group (!p.prerequisite.belongs (t));
+
+ const target_type& rtt (mod
+ ? (group ? bmi::static_type : tts.bmi)
+ : (group ? obj::static_type : tts.obj));
+
+ fail << "synthesized dependency for prerequisite " << p << " "
+ << "would be incompatible with existing target " << *pt <<
+ info << "existing prerequisite " << p1 << " does not match "
+ << p <<
+ info << p1 << " resolves to target " << tp1 <<
+ info << p << " resolves to target " << tp <<
+ info << "specify corresponding " << rtt.name << "{} "
+ << "dependency explicitly";
+ }
+
+ break;
+ }
+ }
+ }
+
+ md.binless = binless;
+ md.start = start;
+
+ switch (a)
+ {
+ case perform_update_id: return [this] (action a, const target& t)
+ {
+ return perform_update (a, t);
+ };
+ case perform_clean_id: return [this] (action a, const target& t)
+ {
+ return perform_clean (a, t);
+ };
+ default: return noop_recipe; // Configure update.
+ }
+ }
+
+ void link_rule::
+ append_libraries (strings& args,
+ const file& l, bool la, lflags lf,
+ const scope& bs, action a, linfo li) const
+ {
+ struct data
+ {
+ strings& args;
+ const file& l;
+ action a;
+ linfo li;
+ compile_target_types tts;
+ } d {args, l, a, li, compile_types (li.type)};
+
+ auto imp = [] (const file&, bool la)
+ {
+ return la;
+ };
+
+ auto lib = [&d, this] (const file* const* lc,
+ const string& p,
+ lflags f,
+ bool)
+ {
+ const file* l (lc != nullptr ? *lc : nullptr);
+
+ if (l == nullptr)
+ {
+ // Don't try to link a library (whether -lfoo or foo.lib) to a
+ // static library.
+ //
+ if (d.li.type != otype::a)
+ d.args.push_back (p);
+ }
+ else
+ {
+ bool lu (l->is_a<libux> ());
+
+ // The utility/non-utility case is tricky. Consider these two
+ // scenarios:
+ //
+ // exe -> (libu1-e -> libu1-e) -> (liba) -> libu-a -> (liba1)
+ // exe -> (liba) -> libu1-a -> libu1-a -> (liba1) -> libu-a1
+ //
+ // Libraries that should be linked are in '()'. That is, we need to
+ // link the initial sequence of utility libraries and then, after
+ // encountering a first non-utility, only link non-utilities
+ // (because they already contain their utility's object files).
+ //
+ if (lu)
+ {
+ for (ptrdiff_t i (-1); lc[i] != nullptr; --i)
+ if (!lc[i]->is_a<libux> ())
+ return;
+ }
+
+ if (d.li.type == otype::a)
+ {
+ // Linking a utility library to a static library.
+ //
+ // Note that utility library prerequisites of utility libraries
+ // are automatically handled by process_libraries(). So all we
+ // have to do is implement the "thin archive" logic.
+ //
+ // We may also end up trying to link a non-utility library to a
+ // static library via a utility library (direct linking is taken
+ // care of by perform_update()). So we cut it off here.
+ //
+ if (!lu)
+ return;
+
+ if (l->mtime () == timestamp_unreal) // Binless.
+ return;
+
+ for (const target* pt: l->prerequisite_targets[d.a])
+ {
+ if (pt == nullptr)
+ continue;
+
+ if (modules)
+ {
+ if (pt->is_a<bmix> ()) // @@ MODHDR: hbmix{} has no objx{}
+ pt = find_adhoc_member (*pt, d.tts.obj);
+ }
+
+ // We could have dependency diamonds with utility libraries.
+ // Repeats will be handled by the linker (in fact, it could be
+ // required to repeat them to satisfy all the symbols) but here
+ // we have to suppress duplicates ourselves.
+ //
+ if (const file* f = pt->is_a<objx> ())
+ {
+ string p (relative (f->path ()).string ());
+ if (find (d.args.begin (), d.args.end (), p) == d.args.end ())
+ d.args.push_back (move (p));
+ }
+ }
+ }
+ else
+ {
+ // Linking a library to a shared library or executable.
+ //
+
+ if (l->mtime () == timestamp_unreal) // Binless.
+ return;
+
+ // On Windows a shared library is a DLL with the import library as
+ // an ad hoc group member. MinGW though can link directly to DLLs
+ // (see search_library() for details).
+ //
+ if (tclass == "windows" && l->is_a<libs> ())
+ {
+ if (const libi* li = find_adhoc_member<libi> (*l))
+ l = li;
+ }
+
+ string p (relative (l->path ()).string ());
+
+ if (f & lflag_whole)
+ {
+ if (tsys == "win32-msvc")
+ {
+ p.insert (0, "/WHOLEARCHIVE:"); // Only available from VC14U2.
+ }
+ else if (tsys == "darwin")
+ {
+ p.insert (0, "-Wl,-force_load,");
+ }
+ else
+ {
+ d.args.push_back ("-Wl,--whole-archive");
+ d.args.push_back (move (p));
+ d.args.push_back ("-Wl,--no-whole-archive");
+ return;
+ }
+ }
+
+ d.args.push_back (move (p));
+ }
+ }
+ };
+
+ auto opt = [&d, this] (const file& l,
+ const string& t,
+ bool com,
+ bool exp)
+ {
+ // Don't try to pass any loptions when linking a static library.
+ //
+ if (d.li.type == otype::a)
+ return;
+
+ // If we need an interface value, then use the group (lib{}).
+ //
+ if (const target* g = exp && l.is_a<libs> () ? l.group : &l)
+ {
+ const variable& var (
+ com
+ ? (exp ? c_export_loptions : c_loptions)
+ : (t == x
+ ? (exp ? x_export_loptions : x_loptions)
+ : l.ctx.var_pool[t + (exp ? ".export.loptions" : ".loptions")]));
+
+ append_options (d.args, *g, var);
+ }
+ };
+
+ process_libraries (
+ a, bs, li, sys_lib_dirs, l, la, lf, imp, lib, opt, true);
+ }
+
+ void link_rule::
+ hash_libraries (sha256& cs,
+ bool& update, timestamp mt,
+ const file& l, bool la, lflags lf,
+ const scope& bs, action a, linfo li) const
+ {
+ struct data
+ {
+ sha256& cs;
+ const dir_path& out_root;
+ bool& update;
+ timestamp mt;
+ linfo li;
+ } d {cs, bs.root_scope ()->out_path (), update, mt, li};
+
+ auto imp = [] (const file&, bool la)
+ {
+ return la;
+ };
+
+ auto lib = [&d, this] (const file* const* lc,
+ const string& p,
+ lflags f,
+ bool)
+ {
+ const file* l (lc != nullptr ? *lc : nullptr);
+
+ if (l == nullptr)
+ {
+ if (d.li.type != otype::a)
+ d.cs.append (p);
+ }
+ else
+ {
+ bool lu (l->is_a<libux> ());
+
+ if (lu)
+ {
+ for (ptrdiff_t i (-1); lc[i] != nullptr; --i)
+ if (!lc[i]->is_a<libux> ())
+ return;
+ }
+
+ // We also don't need to do anything special for linking a utility
+ // library to a static library. If any of its object files (or the
+ // set of its object files) changes, then the library will have to
+ // be updated as well. In other words, we use the library timestamp
+ // as a proxy for all of its member's timestamps.
+ //
+ // We do need to cut of the static to static linking, just as in
+ // append_libraries().
+ //
+ if (d.li.type == otype::a && !lu)
+ return;
+
+ if (l->mtime () == timestamp_unreal) // Binless.
+ return;
+
+ // Check if this library renders us out of date.
+ //
+ d.update = d.update || l->newer (d.mt);
+
+ // On Windows a shared library is a DLL with the import library as
+ // an ad hoc group member. MinGW though can link directly to DLLs
+ // (see search_library() for details).
+ //
+ if (tclass == "windows" && l->is_a<libs> ())
+ {
+ if (const libi* li = find_adhoc_member<libi> (*l))
+ l = li;
+ }
+
+ d.cs.append (f);
+ hash_path (d.cs, l->path (), d.out_root);
+ }
+ };
+
+ auto opt = [&d, this] (const file& l,
+ const string& t,
+ bool com,
+ bool exp)
+ {
+ if (d.li.type == otype::a)
+ return;
+
+ if (const target* g = exp && l.is_a<libs> () ? l.group : &l)
+ {
+ const variable& var (
+ com
+ ? (exp ? c_export_loptions : c_loptions)
+ : (t == x
+ ? (exp ? x_export_loptions : x_loptions)
+ : l.ctx.var_pool[t + (exp ? ".export.loptions" : ".loptions")]));
+
+ hash_options (d.cs, *g, var);
+ }
+ };
+
+ process_libraries (
+ a, bs, li, sys_lib_dirs, l, la, lf, imp, lib, opt, true);
+ }
+
+ void link_rule::
+ rpath_libraries (strings& args,
+ const target& t,
+ const scope& bs,
+ action a,
+ linfo li,
+ bool link) const
+ {
+ // Use -rpath-link only on targets that support it (Linux, *BSD). Note
+ // that we don't really need it for top-level libraries.
+ //
+ if (link)
+ {
+ if (tclass != "linux" && tclass != "bsd")
+ return;
+ }
+
+ auto imp = [link] (const file& l, bool la)
+ {
+ // If we are not rpath-link'ing, then we only need to rpath interface
+ // libraries (they will include rpath's for their implementations)
+ // Otherwise, we have to do this recursively. In both cases we also
+ // want to see through utility libraries.
+ //
+ // The rpath-link part is tricky: ideally we would like to get only
+ // implementations and only of shared libraries. We are not interested
+ // in interfaces because we are linking their libraries explicitly.
+ // However, in our model there is no such thing as "implementation
+ // only"; it is either interface or interface and implementation. So
+ // we are going to rpath-link all of them which should be harmless
+ // except for some noise on the command line.
+ //
+ //
+ return (link ? !la : false) || l.is_a<libux> ();
+ };
+
+ // Package the data to keep within the 2-pointer small std::function
+ // optimization limit.
+ //
+ struct
+ {
+ strings& args;
+ bool link;
+ } d {args, link};
+
+ auto lib = [&d, this] (const file* const* lc,
+ const string& f,
+ lflags,
+ bool sys)
+ {
+ const file* l (lc != nullptr ? *lc : nullptr);
+
+ // We don't rpath system libraries. Why, you may ask? There are many
+ // good reasons and I have them written on a napkin somewhere...
+ //
+ if (sys)
+ return;
+
+ if (l != nullptr)
+ {
+ if (!l->is_a<libs> ())
+ return;
+
+ if (l->mtime () == timestamp_unreal) // Binless.
+ return;
+ }
+ else
+ {
+ // This is an absolute path and we need to decide whether it is
+ // a shared or static library. Doesn't seem there is anything
+ // better than checking for a platform-specific extension (maybe
+ // we should cache it somewhere).
+ //
+ size_t p (path::traits_type::find_extension (f));
+
+ if (p == string::npos)
+ return;
+
+ ++p; // Skip dot.
+
+ bool c (true);
+ const char* e;
+
+ if (tclass == "windows") {e = "dll"; c = false;}
+ else if (tsys == "darwin") e = "dylib";
+ else e = "so";
+
+ if ((c
+ ? f.compare (p, string::npos, e)
+ : casecmp (f.c_str () + p, e)) != 0)
+ return;
+ }
+
+ // Ok, if we are here then it means we have a non-system, shared
+ // library and its absolute path is in f.
+ //
+ string o (d.link ? "-Wl,-rpath-link," : "-Wl,-rpath,");
+
+ size_t p (path::traits_type::rfind_separator (f));
+ assert (p != string::npos);
+
+ o.append (f, 0, (p != 0 ? p : 1)); // Don't include trailing slash.
+ d.args.push_back (move (o));
+ };
+
+ // In case we don't have the "small function object" optimization.
+ //
+ const function<bool (const file&, bool)> impf (imp);
+ const function<
+ void (const file* const*, const string&, lflags, bool)> libf (lib);
+
+ for (const prerequisite_target& pt: t.prerequisite_targets[a])
+ {
+ if (pt == nullptr)
+ continue;
+
+ bool la;
+ const file* f;
+
+ if ((la = (f = pt->is_a<liba> ())) ||
+ (la = (f = pt->is_a<libux> ())) ||
+ ( f = pt->is_a<libs> ()))
+ {
+ if (!link && !la)
+ {
+ // Top-level shared library dependency.
+ //
+ if (!f->path ().empty ()) // Not binless.
+ {
+ // It is either matched or imported so should be a cc library.
+ //
+ if (!cast_false<bool> (f->vars[c_system]))
+ args.push_back (
+ "-Wl,-rpath," + f->path ().directory ().string ());
+ }
+ }
+
+ process_libraries (a, bs, li, sys_lib_dirs,
+ *f, la, pt.data,
+ impf, libf, nullptr);
+ }
+ }
+ }
+
+ // Filter link.exe noise (msvc.cxx).
+ //
+ void
+ msvc_filter_link (ifdstream&, const file&, otype);
+
+ // Translate target CPU to the link.exe/lib.exe /MACHINE option.
+ //
+ const char*
+ msvc_machine (const string& cpu); // msvc.cxx
+
+ target_state link_rule::
+ perform_update (action a, const target& xt) const
+ {
+ tracer trace (x, "link_rule::perform_update");
+
+ const file& t (xt.as<file> ());
+ const path& tp (t.path ());
+
+ context& ctx (t.ctx);
+
+ const scope& bs (t.base_scope ());
+ const scope& rs (*bs.root_scope ());
+
+ match_data& md (t.data<match_data> ());
+
+ // Unless the outer install rule signalled that this is update for
+ // install, signal back that we've performed plain update.
+ //
+ if (!md.for_install)
+ md.for_install = false;
+
+ bool for_install (*md.for_install);
+
+ ltype lt (link_type (t));
+ otype ot (lt.type);
+ linfo li (link_info (bs, ot));
+ compile_target_types tts (compile_types (ot));
+
+ bool binless (md.binless);
+ assert (ot != otype::e || !binless); // Sanity check.
+
+ // Determine if we are out-of-date.
+ //
+ bool update (false);
+ bool scratch (false);
+ timestamp mt (binless ? timestamp_unreal : t.load_mtime ());
+
+ // Update prerequisites. We determine if any relevant non-ad hoc ones
+ // render us out-of-date manually below.
+ //
+ // Note that execute_prerequisites() blanks out all the ad hoc
+ // prerequisites so we don't need to worry about them from now on.
+ //
+ target_state ts;
+
+ if (optional<target_state> s =
+ execute_prerequisites (a,
+ t,
+ mt,
+ [] (const target&, size_t) {return false;}))
+ ts = *s;
+ else
+ {
+ // An ad hoc prerequisite renders us out-of-date. Let's update from
+ // scratch for good measure.
+ //
+ scratch = update = true;
+ ts = target_state::changed;
+ }
+
+ // Check for the for_install variable on each prerequisite and blank out
+ // those that don't match. Note that we have to do it after updating
+ // prerequisites to keep the dependency counts straight.
+ //
+ if (const variable* var_fi = ctx.var_pool.find ("for_install"))
+ {
+ // Parallel prerequisites/prerequisite_targets loop.
+ //
+ size_t i (md.start);
+ for (prerequisite_member p: group_prerequisite_members (a, t))
+ {
+ const target*& pt (t.prerequisite_targets[a][i++]);
+
+ if (pt == nullptr)
+ continue;
+
+ if (lookup l = p.prerequisite.vars[var_fi])
+ {
+ if (cast<bool> (l) != for_install)
+ {
+ l5 ([&]{trace << "excluding " << *pt << " due to for_install";});
+ pt = nullptr;
+ }
+ }
+ }
+ }
+
+ // (Re)generate pkg-config's .pc file. While the target itself might be
+ // up-to-date from a previous run, there is no guarantee that .pc exists
+ // or also up-to-date. So to keep things simple we just regenerate it
+ // unconditionally.
+ //
+ // Also, if you are wondering why don't we just always produce this .pc,
+ // install or no install, the reason is unless and until we are updating
+ // for install, we have no idea where-to things will be installed.
+ //
+ if (for_install && lt.library () && !lt.utility)
+ pkgconfig_save (a, t, lt.static_library (), binless);
+
+ // If we have no binary to build then we are done.
+ //
+ if (binless)
+ {
+ t.mtime (timestamp_unreal);
+ return ts;
+ }
+
+ // Open the dependency database (do it before messing with Windows
+ // manifests to diagnose missing output directory).
+ //
+ depdb dd (tp + ".d");
+
+ // If targeting Windows, take care of the manifest.
+ //
+ path manifest; // Manifest itself (msvc) or compiled object file.
+ timestamp rpath_timestamp = timestamp_nonexistent; // DLLs timestamp.
+
+ if (lt.executable () && tclass == "windows")
+ {
+ // First determine if we need to add our rpath emulating assembly. The
+ // assembly itself is generated later, after updating the target. Omit
+ // it if we are updating for install.
+ //
+ if (!for_install && cast_true<bool> (t["bin.rpath.auto"]))
+ rpath_timestamp = windows_rpath_timestamp (t, bs, a, li);
+
+ auto p (windows_manifest (t, rpath_timestamp != timestamp_nonexistent));
+ path& mf (p.first);
+ timestamp mf_mt (p.second);
+
+ if (tsys == "mingw32")
+ {
+ // Compile the manifest into the object file with windres. While we
+ // are going to synthesize an .rc file to pipe to windres' stdin, we
+ // will still use .manifest to check if everything is up-to-date.
+ //
+ manifest = mf + ".o";
+
+ if (mf_mt == timestamp_nonexistent || mf_mt > mtime (manifest))
+ {
+ path of (relative (manifest));
+
+ const process_path& rc (cast<process_path> (rs["bin.rc.path"]));
+
+ // @@ Would be good to add this to depdb (e.g,, rc changes).
+ //
+ const char* args[] = {
+ rc.recall_string (),
+ "--input-format=rc",
+ "--output-format=coff",
+ "-o", of.string ().c_str (),
+ nullptr};
+
+ if (verb >= 3)
+ print_process (args);
+
+ if (!ctx.dry_run)
+ {
+ auto_rmfile rm (of);
+
+ try
+ {
+ process pr (rc, args, -1);
+
+ try
+ {
+ ofdstream os (move (pr.out_fd));
+
+ // 1 is resource ID, 24 is RT_MANIFEST. We also need to
+ // escape Windows path backslashes.
+ //
+ os << "1 24 \"";
+
+ const string& s (mf.string ());
+ for (size_t i (0), j;; i = j + 1)
+ {
+ j = s.find ('\\', i);
+ os.write (s.c_str () + i,
+ (j == string::npos ? s.size () : j) - i);
+
+ if (j == string::npos)
+ break;
+
+ os.write ("\\\\", 2);
+ }
+
+ os << "\"" << endl;
+
+ os.close ();
+ rm.cancel ();
+ }
+ catch (const io_error& e)
+ {
+ if (pr.wait ()) // Ignore if child failed.
+ fail << "unable to pipe resource file to " << args[0]
+ << ": " << e;
+ }
+
+ run_finish (args, pr);
+ }
+ catch (const process_error& e)
+ {
+ error << "unable to execute " << args[0] << ": " << e;
+
+ if (e.child)
+ exit (1);
+
+ throw failed ();
+ }
+ }
+
+ update = true; // Manifest changed, force update.
+ }
+ }
+ else
+ {
+ manifest = move (mf); // Save for link.exe's /MANIFESTINPUT.
+
+ if (mf_mt == timestamp_nonexistent || mf_mt > mt)
+ update = true; // Manifest changed, force update.
+ }
+ }
+
+ // Check/update the dependency database.
+ //
+ // First should come the rule name/version.
+ //
+ if (dd.expect (rule_id) != nullptr)
+ l4 ([&]{trace << "rule mismatch forcing update of " << t;});
+
+ lookup ranlib;
+
+ // Then the linker checksum (ar/ranlib or the compiler).
+ //
+ if (lt.static_library ())
+ {
+ ranlib = rs["bin.ranlib.path"];
+
+ const char* rl (
+ ranlib
+ ? cast<string> (rs["bin.ranlib.checksum"]).c_str ()
+ : "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855");
+
+ if (dd.expect (cast<string> (rs["bin.ar.checksum"])) != nullptr)
+ l4 ([&]{trace << "ar mismatch forcing update of " << t;});
+
+ if (dd.expect (rl) != nullptr)
+ l4 ([&]{trace << "ranlib mismatch forcing update of " << t;});
+ }
+ else
+ {
+ // For VC we use link.exe directly.
+ //
+ const string& cs (
+ cast<string> (
+ rs[tsys == "win32-msvc"
+ ? ctx.var_pool["bin.ld.checksum"]
+ : x_checksum]));
+
+ if (dd.expect (cs) != nullptr)
+ l4 ([&]{trace << "linker mismatch forcing update of " << t;});
+ }
+
+ // Next check the target. While it might be incorporated into the linker
+ // checksum, it also might not (e.g., VC link.exe).
+ //
+ if (dd.expect (ctgt.string ()) != nullptr)
+ l4 ([&]{trace << "target mismatch forcing update of " << t;});
+
+ // Start building the command line. While we don't yet know whether we
+ // will really need it, we need to hash it to find out. So the options
+ // are to either replicate the exact process twice, first for hashing
+ // then for building or to go ahead and start building and hash the
+ // result. The first approach is probably more efficient while the
+ // second is simpler. Let's got with the simpler for now (actually it's
+ // kind of a hybrid).
+ //
+ cstrings args {nullptr}; // Reserve one for config.bin.ar/config.x.
+
+ // Storage.
+ //
+ string arg1, arg2;
+ strings sargs;
+
+ if (lt.static_library ())
+ {
+ if (tsys == "win32-msvc")
+ {
+ // lib.exe has /LIBPATH but it's not clear/documented what it's used
+ // for. Perhaps for link-time code generation (/LTCG)? If that's the
+ // case, then we may need to pass *.loptions.
+ //
+ args.push_back ("/NOLOGO");
+
+ // Add /MACHINE.
+ //
+ args.push_back (msvc_machine (cast<string> (rs[x_target_cpu])));
+ }
+ else
+ {
+ // If the user asked for ranlib, don't try to do its function with
+ // -s. Some ar implementations (e.g., the LLVM one) don't support
+ // leading '-'.
+ //
+ arg1 = ranlib ? "rc" : "rcs";
+
+ // For utility libraries use thin archives if possible.
+ //
+ // Thin archives are supported by GNU ar since binutils 2.19.1 and
+ // LLVM ar since LLVM 3.8.0. Note that strictly speaking thin
+ // archives also have to be supported by the linker but it is
+ // probably safe to assume that the two came from the same version
+ // of binutils/LLVM.
+ //
+ if (lt.utility)
+ {
+ const string& id (cast<string> (rs["bin.ar.id"]));
+
+ for (bool g (id == "gnu"); g || id == "llvm"; ) // Breakout loop.
+ {
+ auto mj (cast<uint64_t> (rs["bin.ar.version.major"]));
+ if (mj < (g ? 2 : 3)) break;
+ if (mj == (g ? 2 : 3))
+ {
+ auto mi (cast<uint64_t> (rs["bin.ar.version.minor"]));
+ if (mi < (g ? 18 : 8)) break;
+ if (mi == 18 && g)
+ {
+ auto pa (cast<uint64_t> (rs["bin.ar.version.patch"]));
+ if (pa < 1) break;
+ }
+ }
+
+ arg1 += 'T';
+ break;
+ }
+ }
+
+ args.push_back (arg1.c_str ());
+ }
+
+ append_options (args, t, c_aoptions);
+ append_options (args, t, x_aoptions);
+ }
+ else
+ {
+ if (tsys == "win32-msvc")
+ {
+ // We are using link.exe directly so don't pass the compiler
+ // options.
+ }
+ else
+ {
+ append_options (args, t, c_coptions);
+ append_options (args, t, x_coptions);
+ append_options (args, tstd);
+ }
+
+ append_options (args, t, c_loptions);
+ append_options (args, t, x_loptions);
+
+ // Extra system library dirs (last).
+ //
+ // @@ /LIBPATH:<path>, not /LIBPATH <path>
+ //
+ assert (sys_lib_dirs_extra <= sys_lib_dirs.size ());
+ append_option_values (
+ args,
+ cclass == compiler_class::msvc ? "/LIBPATH:" : "-L",
+ sys_lib_dirs.begin () + sys_lib_dirs_extra, sys_lib_dirs.end (),
+ [] (const dir_path& d) {return d.string ().c_str ();});
+
+ // Handle soname/rpath.
+ //
+ if (tclass == "windows")
+ {
+ // Limited emulation for Windows with no support for user-defined
+ // rpath/rpath-link.
+ //
+ lookup l;
+
+ if ((l = t["bin.rpath"]) && !l->empty ())
+ fail << ctgt << " does not support rpath";
+
+ if ((l = t["bin.rpath_link"]) && !l->empty ())
+ fail << ctgt << " does not support rpath-link";
+ }
+ else
+ {
+ // Set soname.
+ //
+ if (lt.shared_library ())
+ {
+ const libs_paths& paths (md.libs_paths);
+ const string& leaf (paths.effect_soname ().leaf ().string ());
+
+ if (tclass == "macos")
+ {
+ // With Mac OS 10.5 (Leopard) Apple finally caved in and gave us
+ // a way to emulate vanilla -rpath.
+ //
+ // It may seem natural to do something different on update for
+ // install. However, if we don't make it @rpath, then the user
+ // won't be able to use config.bin.rpath for installed libraries.
+ //
+ arg1 = "-install_name";
+ arg2 = "@rpath/" + leaf;
+ }
+ else
+ arg1 = "-Wl,-soname," + leaf;
+
+ if (!arg1.empty ())
+ args.push_back (arg1.c_str ());
+
+ if (!arg2.empty ())
+ args.push_back (arg2.c_str ());
+ }
+
+ // Add rpaths. We used to first add the ones specified by the user
+ // so that they take precedence. But that caused problems if we have
+ // old versions of the libraries sitting in the rpath location
+ // (e.g., installed libraries). And if you think about this, it's
+ // probably correct to prefer libraries that we explicitly imported
+ // to the ones found via rpath.
+ //
+ // Note also that if this is update for install, then we don't add
+ // rpath of the imported libraries (i.e., we assume they are also
+ // installed). But we add -rpath-link for some platforms.
+ //
+ if (cast_true<bool> (t[for_install
+ ? "bin.rpath_link.auto"
+ : "bin.rpath.auto"]))
+ rpath_libraries (sargs, t, bs, a, li, for_install /* link */);
+
+ lookup l;
+
+ if ((l = t["bin.rpath"]) && !l->empty ())
+ for (const dir_path& p: cast<dir_paths> (l))
+ sargs.push_back ("-Wl,-rpath," + p.string ());
+
+ if ((l = t["bin.rpath_link"]) && !l->empty ())
+ {
+ // Only certain targets support -rpath-link (Linux, *BSD).
+ //
+ if (tclass != "linux" && tclass != "bsd")
+ fail << ctgt << " does not support rpath-link";
+
+ for (const dir_path& p: cast<dir_paths> (l))
+ sargs.push_back ("-Wl,-rpath-link," + p.string ());
+ }
+ }
+ }
+
+ // All the options should now be in. Hash them and compare with the db.
+ //
+ {
+ sha256 cs;
+
+ for (size_t i (1); i != args.size (); ++i)
+ cs.append (args[i]);
+
+ for (size_t i (0); i != sargs.size (); ++i)
+ cs.append (sargs[i]);
+
+ // @@ Note that we don't hash output options so if one of the ad hoc
+ // members that we manage gets renamed, we will miss a rebuild.
+
+ if (dd.expect (cs.string ()) != nullptr)
+ l4 ([&]{trace << "options mismatch forcing update of " << t;});
+ }
+
+ // Finally, hash and compare the list of input files.
+ //
+ // Should we capture actual file names or their checksum? The only good
+ // reason for capturing actual files is diagnostics: we will be able to
+ // pinpoint exactly what is causing the update. On the other hand, the
+ // checksum is faster and simpler. And we like simple.
+ //
+ const file* def (nullptr); // Cached if present.
+ {
+ sha256 cs;
+
+ for (const prerequisite_target& p: t.prerequisite_targets[a])
+ {
+ const target* pt (p.target);
+
+ if (pt == nullptr)
+ continue;
+
+ // If this is bmi*{}, then obj*{} is its ad hoc member.
+ //
+ if (modules)
+ {
+ if (pt->is_a<bmix> ()) // @@ MODHDR: hbmix{} has no objx{}
+ pt = find_adhoc_member (*pt, tts.obj);
+ }
+
+ const file* f;
+ bool la (false), ls (false);
+
+ // We link utility libraries to everything except other utility
+ // libraries. In case of linking to liba{} we follow the "thin
+ // archive" lead and "see through" to their object file
+ // prerequisites (recursively, until we encounter a non-utility).
+ //
+ if ((f = pt->is_a<objx> ()) ||
+ (!lt.utility &&
+ (la = (f = pt->is_a<libux> ()))) ||
+ (!lt.static_library () &&
+ ((la = (f = pt->is_a<liba> ())) ||
+ (ls = (f = pt->is_a<libs> ())))))
+ {
+ // Link all the dependent interface libraries (shared) or interface
+ // and implementation (static), recursively.
+ //
+ // Also check if any of them render us out of date. The tricky
+ // case is, say, a utility library (static) that depends on a
+ // shared library. When the shared library is updated, there is no
+ // reason to re-archive the utility but those who link the utility
+ // have to "see through" the changes in the shared library.
+ //
+ if (la || ls)
+ {
+ hash_libraries (cs, update, mt, *f, la, p.data, bs, a, li);
+ f = nullptr; // Timestamp checked by hash_libraries().
+ }
+ else
+ hash_path (cs, f->path (), rs.out_path ());
+ }
+ else if ((f = pt->is_a<bin::def> ()))
+ {
+ if (tclass == "windows" && !lt.static_library ())
+ {
+ // At least link.exe only allows a single .def file.
+ //
+ if (def != nullptr)
+ fail << "multiple module definition files specified for " << t;
+
+ hash_path (cs, f->path (), rs.out_path ());
+ def = f;
+ }
+ else
+ f = nullptr; // Not an input.
+ }
+ else
+ f = pt->is_a<exe> (); // Consider executable mtime (e.g., linker).
+
+ // Check if this input renders us out of date.
+ //
+ if (f != nullptr)
+ update = update || f->newer (mt);
+ }
+
+ // Treat it as input for both MinGW and VC (mtime checked above).
+ //
+ if (!manifest.empty ())
+ hash_path (cs, manifest, rs.out_path ());
+
+ // Treat *.libs variable values as inputs, not options.
+ //
+ if (!lt.static_library ())
+ {
+ hash_options (cs, t, c_libs);
+ hash_options (cs, t, x_libs);
+ }
+
+ if (dd.expect (cs.string ()) != nullptr)
+ l4 ([&]{trace << "file set mismatch forcing update of " << t;});
+ }
+
+ // If any of the above checks resulted in a mismatch (different linker,
+ // options or input file set), or if the database is newer than the
+ // target (interrupted update) then force the target update. Also note
+ // this situation in the "from scratch" flag.
+ //
+ if (dd.writing () || dd.mtime > mt)
+ scratch = update = true;
+
+ dd.close ();
+
+ // If nothing changed, then we are done.
+ //
+ if (!update)
+ return ts;
+
+ // Ok, so we are updating. Finish building the command line.
+ //
+ string in, out, out1, out2, out3; // Storage.
+
+ // Translate paths to relative (to working directory) ones. This results
+ // in easier to read diagnostics.
+ //
+ path relt (relative (tp));
+
+ const process_path* ld (nullptr);
+ if (lt.static_library ())
+ {
+ ld = &cast<process_path> (rs["bin.ar.path"]);
+
+ if (tsys == "win32-msvc")
+ {
+ out = "/OUT:" + relt.string ();
+ args.push_back (out.c_str ());
+ }
+ else
+ args.push_back (relt.string ().c_str ());
+ }
+ else
+ {
+ // The options are usually similar enough to handle executables
+ // and shared libraries together.
+ //
+ if (tsys == "win32-msvc")
+ {
+ // Using link.exe directly.
+ //
+ ld = &cast<process_path> (rs["bin.ld.path"]);
+ args.push_back ("/NOLOGO");
+
+ if (ot == otype::s)
+ args.push_back ("/DLL");
+
+ // Add /MACHINE.
+ //
+ args.push_back (msvc_machine (cast<string> (rs[x_target_cpu])));
+
+ // Unless explicitly enabled with /INCREMENTAL, disable incremental
+ // linking (it is implicitly enabled if /DEBUG is specified). The
+ // reason is the .ilk file: its name cannot be changed and if we
+ // have, say, foo.exe and foo.dll, then they will end up stomping on
+ // each other's .ilk's.
+ //
+ // So the idea is to disable it by default but let the user request
+ // it explicitly if they are sure their project doesn't suffer from
+ // the above issue. We can also have something like 'incremental'
+ // config initializer keyword for this.
+ //
+ // It might also be a good idea to ask Microsoft to add an option.
+ //
+ if (!find_option ("/INCREMENTAL", args, true))
+ args.push_back ("/INCREMENTAL:NO");
+
+ if (ctype == compiler_type::clang)
+ {
+ // According to Clang's MSVC.cpp, we shall link libcmt.lib (static
+ // multi-threaded runtime) unless -nostdlib or -nostartfiles is
+ // specified.
+ //
+ if (!find_options ({"-nostdlib", "-nostartfiles"}, t, c_coptions) &&
+ !find_options ({"-nostdlib", "-nostartfiles"}, t, x_coptions))
+ args.push_back ("/DEFAULTLIB:libcmt.lib");
+ }
+
+ // If you look at the list of libraries Visual Studio links by
+ // default, it includes everything and a couple of kitchen sinks
+ // (winspool32.lib, ole32.lib, odbc32.lib, etc) while we want to
+ // keep our low-level build as pure as possible. However, there seem
+ // to be fairly essential libraries that are not linked by link.exe
+ // by default (use /VERBOSE:LIB to see the list). For example, MinGW
+ // by default links advapi32, shell32, user32, and kernel32. And so
+ // we follow suit and make sure those are linked. advapi32 and
+ // kernel32 are already on the default list and we only need to add
+ // the other two.
+ //
+ // The way we are going to do it is via the /DEFAULTLIB option
+ // rather than specifying the libraries as normal inputs (as VS
+ // does). This way the user can override our actions with the
+ // /NODEFAULTLIB option.
+ //
+ args.push_back ("/DEFAULTLIB:shell32.lib");
+ args.push_back ("/DEFAULTLIB:user32.lib");
+
+ // Take care of the manifest (will be empty for the DLL).
+ //
+ if (!manifest.empty ())
+ {
+ out3 = "/MANIFESTINPUT:";
+ out3 += relative (manifest).string ();
+ args.push_back ("/MANIFEST:EMBED");
+ args.push_back (out3.c_str ());
+ }
+
+ if (def != nullptr)
+ {
+ in = "/DEF:" + relative (def->path ()).string ();
+ args.push_back (in.c_str ());
+ }
+
+ if (ot == otype::s)
+ {
+ // On Windows libs{} is the DLL and an ad hoc group member is the
+ // import library.
+ //
+ // This will also create the .exp export file. Its name will be
+ // derived from the import library by changing the extension.
+ // Lucky for us -- there is no option to name it.
+ //
+ const file& imp (*find_adhoc_member<libi> (t));
+
+ out2 = "/IMPLIB:";
+ out2 += relative (imp.path ()).string ();
+ args.push_back (out2.c_str ());
+ }
+
+ // If we have /DEBUG then name the .pdb file. It is an ad hoc group
+ // member.
+ //
+ if (find_option ("/DEBUG", args, true))
+ {
+ const file& pdb (
+ *find_adhoc_member<file> (t, *bs.find_target_type ("pdb")));
+
+ out1 = "/PDB:";
+ out1 += relative (pdb.path ()).string ();
+ args.push_back (out1.c_str ());
+ }
+
+ // @@ An executable can have an import library and VS seems to
+ // always name it. I wonder what would trigger its generation?
+ // Could it be the presence of export symbols? Yes, link.exe will
+ // generate the import library iff there are exported symbols.
+ // Which means there could be a DLL without an import library
+ // (which we currently don't handle very well).
+ //
+ out = "/OUT:" + relt.string ();
+ args.push_back (out.c_str ());
+ }
+ else
+ {
+ switch (cclass)
+ {
+ case compiler_class::gcc:
+ {
+ ld = &cpath;
+
+ // Add the option that triggers building a shared library and
+ // take care of any extras (e.g., import library).
+ //
+ if (ot == otype::s)
+ {
+ if (tclass == "macos")
+ args.push_back ("-dynamiclib");
+ else
+ args.push_back ("-shared");
+
+ if (tsys == "mingw32")
+ {
+ // On Windows libs{} is the DLL and an ad hoc group member
+ // is the import library.
+ //
+ const file& imp (*find_adhoc_member<libi> (t));
+ out = "-Wl,--out-implib=" + relative (imp.path ()).string ();
+ args.push_back (out.c_str ());
+ }
+ }
+
+ args.push_back ("-o");
+ args.push_back (relt.string ().c_str ());
+
+ // For MinGW the .def file is just another input.
+ //
+ if (def != nullptr)
+ {
+ in = relative (def->path ()).string ();
+ args.push_back (in.c_str ());
+ }
+
+ break;
+ }
+ case compiler_class::msvc: assert (false);
+ }
+ }
+ }
+
+ args[0] = ld->recall_string ();
+
+ // Append input files noticing the position of the first.
+ //
+#ifdef _WIN32
+ size_t args_input (args.size ());
+#endif
+
+ // The same logic as during hashing above. See also a similar loop
+ // inside append_libraries().
+ //
+ for (const prerequisite_target& p: t.prerequisite_targets[a])
+ {
+ const target* pt (p.target);
+
+ if (pt == nullptr)
+ continue;
+
+ if (modules)
+ {
+ if (pt->is_a<bmix> ()) // @@ MODHDR: hbmix{} has no objx{}
+ pt = find_adhoc_member (*pt, tts.obj);
+ }
+
+ const file* f;
+ bool la (false), ls (false);
+
+ if ((f = pt->is_a<objx> ()) ||
+ (!lt.utility &&
+ (la = (f = pt->is_a<libux> ()))) ||
+ (!lt.static_library () &&
+ ((la = (f = pt->is_a<liba> ())) ||
+ (ls = (f = pt->is_a<libs> ())))))
+ {
+ if (la || ls)
+ append_libraries (sargs, *f, la, p.data, bs, a, li);
+ else
+ sargs.push_back (relative (f->path ()).string ()); // string()&&
+ }
+ }
+
+ // For MinGW manifest is an object file.
+ //
+ if (!manifest.empty () && tsys == "mingw32")
+ sargs.push_back (relative (manifest).string ());
+
+ // Shallow-copy sargs to args. Why not do it as we go along pushing into
+ // sargs? Because of potential reallocations in sargs.
+ //
+ for (const string& a: sargs)
+ args.push_back (a.c_str ());
+
+ if (!lt.static_library ())
+ {
+ append_options (args, t, c_libs);
+ append_options (args, t, x_libs);
+ }
+
+ args.push_back (nullptr);
+
+ // Cleanup old (versioned) libraries. Let's do it even for dry-run to
+ // keep things simple.
+ //
+ if (lt.shared_library ())
+ {
+ const libs_paths& paths (md.libs_paths);
+ const path& p (paths.clean);
+
+ if (!p.empty ())
+ try
+ {
+ if (verb >= 4) // Seeing this with -V doesn't really add any value.
+ text << "rm " << p;
+
+ auto rm = [&paths, this] (path&& m, const string&, bool interm)
+ {
+ if (!interm)
+ {
+ // Filter out paths that have one of the current paths as a
+ // prefix.
+ //
+ auto test = [&m] (const path& p)
+ {
+ const string& s (p.string ());
+ return s.empty () || m.string ().compare (0, s.size (), s) != 0;
+ };
+
+ if (test (*paths.real) &&
+ test ( paths.interm) &&
+ test ( paths.soname) &&
+ test ( paths.load) &&
+ test ( paths.link))
+ {
+ try_rmfile (m);
+ try_rmfile (m + ".d");
+
+ if (tsys == "win32-msvc")
+ {
+ try_rmfile (m.base () += ".ilk");
+ try_rmfile (m += ".pdb");
+ }
+ }
+ }
+ return true;
+ };
+
+ // Note: doesn't follow symlinks.
+ //
+ path_search (p, rm, dir_path () /* start */, path_match_flags::none);
+ }
+ catch (const system_error&) {} // Ignore errors.
+ }
+ else if (lt.static_library ())
+ {
+ // We use relative paths to the object files which means we may end
+ // up with different ones depending on CWD and some implementation
+ // treat them as different archive members. So remote the file to
+ // be sure. Note that we ignore errors leaving it to the archiever
+ // to complain.
+ //
+ if (mt != timestamp_nonexistent)
+ try_rmfile (relt, true);
+ }
+
+ if (verb == 1)
+ text << (lt.static_library () ? "ar " : "ld ") << t;
+ else if (verb == 2)
+ print_process (args);
+
+ // Do any necessary fixups to the command line to make it runnable.
+ //
+ // Notice the split in the diagnostics: at verbosity level 1 we print
+ // the "logical" command line while at level 2 and above -- what we are
+ // actually executing.
+ //
+ // On Windows we need to deal with the command line length limit. The
+ // best workaround seems to be passing (part of) the command line in an
+ // "options file" ("response file" in Microsoft's terminology). Both
+ // Microsoft's link.exe/lib.exe as well as GNU g??.exe/ar.exe support
+ // the same @<file> notation (and with a compatible subset of the
+ // content format; see below). Note also that GCC is smart enough to use
+ // an options file to call the underlying linker if we called it with
+ // @<file>. We will also assume that any other linker that we might be
+ // using supports this notation.
+ //
+ // Note that this is a limitation of the host platform, not the target
+ // (and Wine, where these lines are a bit blurred, does not have this
+ // length limitation).
+ //
+#ifdef _WIN32
+ auto_rmfile trm;
+ string targ;
+ {
+ // Calculate the would-be command line length similar to how process'
+ // implementation does it.
+ //
+ auto quote = [s = string ()] (const char* a) mutable -> const char*
+ {
+ return process::quote_argument (a, s);
+ };
+
+ size_t n (0);
+ for (const char* a: args)
+ {
+ if (a != nullptr)
+ {
+ if (n != 0)
+ n++; // For the space separator.
+
+ n += strlen (quote (a));
+ }
+ }
+
+ if (n > 32766) // 32768 - "Unicode terminating null character".
+ {
+ // Use the .t extension (for "temporary").
+ //
+ const path& f ((trm = auto_rmfile (relt + ".t")).path);
+
+ try
+ {
+ ofdstream ofs (f);
+
+ // Both Microsoft and GNU support a space-separated list of
+ // potentially-quoted arguments. GNU also supports backslash-
+ // escaping (whether Microsoft supports it is unclear; but it
+ // definitely doesn't need it for backslashes themselves, for
+ // example, in paths).
+ //
+ bool e (tsys != "win32-msvc"); // Assume GNU if not MSVC.
+ string b;
+
+ for (size_t i (args_input), n (args.size () - 1); i != n; ++i)
+ {
+ const char* a (args[i]);
+
+ if (e) // We will most likely have backslashes so just do it.
+ {
+ for (b.clear (); *a != '\0'; ++a)
+ {
+ if (*a != '\\')
+ b += *a;
+ else
+ b += "\\\\";
+ }
+
+ a = b.c_str ();
+ }
+
+ ofs << (i != args_input ? " " : "") << quote (a);
+ }
+
+ ofs << '\n';
+ ofs.close ();
+ }
+ catch (const io_error& e)
+ {
+ fail << "unable to write " << f << ": " << e;
+ }
+
+ // Replace input arguments with @file.
+ //
+ targ = '@' + f.string ();
+ args.resize (args_input);
+ args.push_back (targ.c_str());
+ args.push_back (nullptr);
+
+ //@@ TODO: leave .t file if linker failed and verb > 2?
+ }
+ }
+#endif
+
+ if (verb > 2)
+ print_process (args);
+
+ // Remove the target file if any of the subsequent (after the linker)
+ // actions fail or if the linker fails but does not clean up its mess
+ // (like link.exe). If we don't do that, then we will end up with a
+ // broken build that is up-to-date.
+ //
+ auto_rmfile rm;
+
+ if (!ctx.dry_run)
+ {
+ rm = auto_rmfile (relt);
+
+ try
+ {
+ // VC tools (both lib.exe and link.exe) send diagnostics to stdout.
+ // Also, link.exe likes to print various gratuitous messages. So for
+ // link.exe we redirect stdout to a pipe, filter that noise out, and
+ // send the rest to stderr.
+ //
+ // For lib.exe (and any other insane linker that may try to pull off
+ // something like this) we are going to redirect stdout to stderr.
+ // For sane compilers this should be harmless.
+ //
+ bool filter (tsys == "win32-msvc" && !lt.static_library ());
+
+ process pr (*ld, args.data (), 0, (filter ? -1 : 2));
+
+ if (filter)
+ {
+ try
+ {
+ ifdstream is (
+ move (pr.in_ofd), fdstream_mode::text, ifdstream::badbit);
+
+ msvc_filter_link (is, t, ot);
+
+ // If anything remains in the stream, send it all to stderr.
+ // Note that the eof check is important: if the stream is at
+ // eof, this and all subsequent writes to the diagnostics stream
+ // will fail (and you won't see a thing).
+ //
+ if (is.peek () != ifdstream::traits_type::eof ())
+ diag_stream_lock () << is.rdbuf ();
+
+ is.close ();
+ }
+ catch (const io_error&) {} // Assume exits with error.
+ }
+
+ run_finish (args, pr);
+ }
+ catch (const process_error& e)
+ {
+ error << "unable to execute " << args[0] << ": " << e;
+
+ // In a multi-threaded program that fork()'ed but did not exec(), it
+ // is unwise to try to do any kind of cleanup (like unwinding the
+ // stack and running destructors).
+ //
+ if (e.child)
+ {
+ rm.cancel ();
+#ifdef _WIN32
+ trm.cancel ();
+#endif
+ exit (1);
+ }
+
+ throw failed ();
+ }
+
+ // VC link.exe creates an import library and .exp file for an
+ // executable if any of its object files export any symbols (think a
+ // unit test linking libus{}). And, no, there is no way to suppress
+ // it. Well, there is a way: create a .def file with an empty EXPORTS
+ // section, pass it to lib.exe to create a dummy .exp (and .lib), and
+ // then pass this empty .exp to link.exe. Wanna go this way? Didn't
+ // think so. Having no way to disable this, the next simplest thing
+ // seems to be just cleaning the mess up.
+ //
+ // Note also that if at some point we decide to support such "shared
+ // executables" (-rdynamic, etc), then it will probably have to be a
+ // different target type (exes{}?) since it will need a different set
+ // of object files (-fPIC so probably objs{}), etc.
+ //
+ if (lt.executable () && tsys == "win32-msvc")
+ {
+ path b (relt.base ());
+ try_rmfile (b + ".lib", true /* ignore_errors */);
+ try_rmfile (b + ".exp", true /* ignore_errors */);
+ }
+ }
+
+ if (ranlib)
+ {
+ const process_path& rl (cast<process_path> (ranlib));
+
+ const char* args[] = {
+ rl.recall_string (),
+ relt.string ().c_str (),
+ nullptr};
+
+ if (verb >= 2)
+ print_process (args);
+
+ if (!ctx.dry_run)
+ run (rl, args);
+ }
+
+ // For Windows generate (or clean up) rpath-emulating assembly.
+ //
+ if (tclass == "windows")
+ {
+ if (lt.executable ())
+ windows_rpath_assembly (t, bs, a, li,
+ cast<string> (rs[x_target_cpu]),
+ rpath_timestamp,
+ scratch);
+ }
+
+ if (lt.shared_library ())
+ {
+ // For shared libraries we may need to create a bunch of symlinks (or
+ // fallback to hardlinks/copies on Windows).
+ //
+ auto ln = [&ctx] (const path& f, const path& l)
+ {
+ if (verb >= 3)
+ text << "ln -sf " << f << ' ' << l;
+
+ if (ctx.dry_run)
+ return;
+
+ try
+ {
+ try
+ {
+ // The -f part.
+ //
+ if (file_exists (l, false /* follow_symlinks */))
+ try_rmfile (l);
+
+ mkanylink (f, l, true /* copy */, true /* relative */);
+ }
+ catch (system_error& e)
+ {
+ throw pair<entry_type, system_error> (entry_type::symlink,
+ move (e));
+ }
+ }
+ catch (const pair<entry_type, system_error>& e)
+ {
+ const char* w (e.first == entry_type::regular ? "copy" :
+ e.first == entry_type::symlink ? "symlink" :
+ e.first == entry_type::other ? "hardlink" :
+ nullptr);
+
+ fail << "unable to make " << w << ' ' << l << ": " << e.second;
+ }
+ };
+
+ const libs_paths& paths (md.libs_paths);
+
+ const path& lk (paths.link);
+ const path& ld (paths.load);
+ const path& so (paths.soname);
+ const path& in (paths.interm);
+
+ const path* f (paths.real);
+
+ if (!in.empty ()) {ln (*f, in); f = &in;}
+ if (!so.empty ()) {ln (*f, so); f = &so;}
+ if (!ld.empty ()) {ln (*f, ld); f = &ld;}
+ if (!lk.empty ()) {ln (*f, lk);}
+ }
+ else if (lt.static_library ())
+ {
+ // Apple ar (from cctools) for some reason truncates fractional
+ // seconds when running on APFS (HFS has a second resolution so it's
+ // not an issue there). This can lead to object files being newer than
+ // the archive, which is naturally bad news. Filed as bug 49604334,
+ // reportedly fixed in Xcode 11 beta 5.
+ //
+ // Note that this block is not inside #ifdef __APPLE__ because we
+ // could be cross-compiling, theoretically. We also make sure we use
+ // Apple's ar (which is (un)recognized as 'generic') instead of, say,
+ // llvm-ar.
+ //
+ if (tsys == "darwin" && cast<string> (rs["bin.ar.id"]) == "generic")
+ {
+ if (!ctx.dry_run)
+ touch (ctx, tp, false /* create */, verb_never);
+ }
+ }
+
+ if (!ctx.dry_run)
+ {
+ rm.cancel ();
+ dd.check_mtime (tp);
+ }
+
+ // Should we go to the filesystem and get the new mtime? We know the
+ // file has been modified, so instead just use the current clock time.
+ // It has the advantage of having the subseconds precision. Plus, in
+ // case of dry-run, the file won't be modified.
+ //
+ t.mtime (system_clock::now ());
+ return target_state::changed;
+ }
+
+ target_state link_rule::
+ perform_clean (action a, const target& xt) const
+ {
+ const file& t (xt.as<file> ());
+
+ ltype lt (link_type (t));
+ const match_data& md (t.data<match_data> ());
+
+ clean_extras extras;
+ clean_adhoc_extras adhoc_extras;
+
+ if (md.binless)
+ ; // Clean prerequsites/members.
+ else
+ {
+ if (tclass != "windows")
+ ; // Everything is the default.
+ else if (tsys == "mingw32")
+ {
+ if (lt.executable ())
+ {
+ extras = {".d", ".dlls/", ".manifest.o", ".manifest"};
+ }
+
+ // For shared and static library it's the default.
+ }
+ else
+ {
+ // Assuming MSVC or alike.
+ //
+ if (lt.executable ())
+ {
+ // Clean up .ilk in case the user enabled incremental linking
+ // (notice that the .ilk extension replaces .exe).
+ //
+ extras = {".d", ".dlls/", ".manifest", "-.ilk"};
+ }
+ else if (lt.shared_library ())
+ {
+ // Clean up .ilk and .exp.
+ //
+ // Note that .exp is based on the .lib, not .dll name. And with
+ // versioning their bases may not be the same.
+ //
+ extras = {".d", "-.ilk"};
+ adhoc_extras.push_back ({libi::static_type, {"-.exp"}});
+ }
+
+ // For static library it's the default.
+ }
+
+ if (extras.empty ())
+ extras = {".d"}; // Default.
+
+#ifdef _WIN32
+ extras.push_back (".t"); // Options file.
+#endif
+ // For shared libraries we may have a bunch of symlinks that we need
+ // to remove.
+ //
+ if (lt.shared_library ())
+ {
+ const libs_paths& lp (md.libs_paths);
+
+ auto add = [&extras] (const path& p)
+ {
+ if (!p.empty ())
+ extras.push_back (p.string ().c_str ());
+ };
+
+ add (lp.link);
+ add (lp.load);
+ add (lp.soname);
+ add (lp.interm);
+ }
+ }
+
+ return perform_clean_extra (a, t, extras, adhoc_extras);
+ }
+ }
+}