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authorBoris Kolpackov <boris@codesynthesis.com>2020-06-09 08:19:33 +0200
committerBoris Kolpackov <boris@codesynthesis.com>2020-06-09 08:19:33 +0200
commit23cbbc7f7cdcb7721d8d1cf4e70ae58184f8cc7e (patch)
tree182c9d097535f704f7899a1de81472b7b936fd03 /libbuild2/rule.cxx
parentb8cffb11a45add241e4b8420ba96e116efccfbd9 (diff)
Factor ad hoc C++ and Buildscript rules into separate files
Diffstat (limited to 'libbuild2/rule.cxx')
-rw-r--r--libbuild2/rule.cxx1225
1 files changed, 0 insertions, 1225 deletions
diff --git a/libbuild2/rule.cxx b/libbuild2/rule.cxx
index ea7186c..86a6b4d 100644
--- a/libbuild2/rule.cxx
+++ b/libbuild2/rule.cxx
@@ -3,10 +3,6 @@
#include <libbuild2/rule.hxx>
-#include <sstream>
-
-#include <libbuild2/file.hxx>
-#include <libbuild2/depdb.hxx>
#include <libbuild2/scope.hxx>
#include <libbuild2/target.hxx>
#include <libbuild2/context.hxx>
@@ -14,11 +10,6 @@
#include <libbuild2/filesystem.hxx>
#include <libbuild2/diagnostics.hxx>
-#include <libbuild2/parser.hxx> // attributes
-
-#include <libbuild2/build/script/parser.hxx>
-#include <libbuild2/build/script/runner.hxx>
-
using namespace std;
using namespace butl;
@@ -366,1220 +357,4 @@ namespace build2
return target_state::unchanged;
}
-
- // adhoc_script_rule
- //
- bool adhoc_script_rule::
- recipe_text (context& ctx, const target& tg, string&& t, attributes& as)
- {
- // Handle and erase recipe-specific attributes.
- //
- optional<string> diag;
- for (auto i (as.begin ()); i != as.end (); )
- {
- attribute& a (*i);
- const string& n (a.name);
-
- if (n == "diag")
- try
- {
- diag = convert<string> (move (a.value));
- }
- catch (const invalid_argument& e)
- {
- fail (as.loc) << "invalid " << n << " attribute value: " << e;
- }
- else
- {
- ++i;
- continue;
- }
-
- i = as.erase (i);
- }
-
- checksum = sha256 (t).string ();
-
- istringstream is (move (t));
- build::script::parser p (ctx);
-
- script = p.pre_parse (tg,
- is, loc.file, loc.line + 1,
- move (diag), as.loc);
-
- return false;
- }
-
- void adhoc_script_rule::
- dump_attributes (ostream& os) const
- {
- // For now we dump it as an attribute whether it was specified or derived
- // from the script. Maybe that's ok (we use this in tests)?
- //
- if (script.diag_name)
- {
- os << " [";
- os << "diag=";
- to_stream (os, name (*script.diag_name), true /* quote */, '@');
- os << ']';
- }
- }
-
- void adhoc_script_rule::
- dump_text (ostream& os, string& ind) const
- {
- os << ind << string (braces, '{') << endl;
- ind += " ";
-
- if (script.depdb_clear)
- os << ind << "depdb clear" << endl;
-
- script::dump (os, ind, script.depdb_lines);
-
- if (script.diag_line)
- {
- os << ind; script::dump (os, *script.diag_line, true /* newline */);
- }
-
- script::dump (os, ind, script.lines);
- ind.resize (ind.size () - 2);
- os << ind << string (braces, '}');
- }
-
- bool adhoc_script_rule::
- match (action a, target& t, const string&, optional<action> fb) const
- {
- if (!fb)
- ;
- // If this is clean for a file target and we are supplying the update,
- // then we will also supply the standard clean.
- //
- else if (a == perform_clean_id &&
- *fb == perform_update_id &&
- t.is_a<file> ())
- ;
- else
- return false;
-
- // It's unfortunate we have to resort to this but we need to remember this
- // in apply().
- //
- t.data (fb.has_value ());
-
- return true;
- }
-
- recipe adhoc_script_rule::
- apply (action a, target& t) const
- {
- // If this is an outer operation (e.g., update-for-test), then delegate to
- // the inner.
- //
- if (a.outer ())
- {
- match_inner (a, t);
- return execute_inner;
- }
-
- // Derive file names for the target and its ad hoc group members, if any.
- //
- if (a == perform_update_id || a == perform_clean_id)
- {
- for (target* m (&t); m != nullptr; m = m->adhoc_member)
- {
- if (auto* p = m->is_a<path_target> ())
- p->derive_path ();
- }
- }
-
- // Inject dependency on the output directory.
- //
- // We do it always instead of only if one of the targets is path-based in
- // case the recipe creates temporary files or some such.
- //
- inject_fsdir (a, t);
-
- // Match prerequisites.
- //
- match_prerequisite_members (a, t);
-
- // See if we are providing the standard clean as a fallback.
- //
- if (t.data<bool> ())
- return &perform_clean_depdb;
-
- if (a == perform_update_id && t.is_a<file> ())
- {
- return [this] (action a, const target& t)
- {
- return perform_update_file (a, t);
- };
- }
- else
- {
- return [this] (action a, const target& t)
- {
- return default_action (a, t);
- };
- }
- }
-
- target_state adhoc_script_rule::
- perform_update_file (action a, const target& xt) const
- {
- tracer trace ("adhoc_script_rule::perform_update_file");
-
- context& ctx (xt.ctx);
-
- const file& t (xt.as<file> ());
- const path& tp (t.path ());
-
- // How should we hash target and prerequisite sets ($> and $<)? We could
- // hash them as target names (i.e., the same as the $>/< content) or as
- // paths (only for path-based targets). While names feel more general,
- // they are also more expensive to compute. And for path-based targets,
- // path is generally a good proxy for the target name. Since the bulk of
- // the ad hoc recipes will presumably be operating exclusively on
- // path-based targets, let's do it both ways.
- //
- auto hash_target = [ns = names ()] (sha256& cs, const target& t) mutable
- {
- if (const path_target* pt = t.is_a<path_target> ())
- cs.append (pt->path ().string ());
- else
- {
- ns.clear ();
- t.as_name (ns);
- for (const name& n: ns)
- to_checksum (cs, n);
- }
- };
-
- // Update prerequisites and determine if any of them render this target
- // out-of-date.
- //
- timestamp mt (t.load_mtime ());
- optional<target_state> ps;
-
- sha256 pcs, ecs;
- {
- // This is essentially ps=execute_prerequisites(a, t, mt) which we
- // cannot use because we need to see ad hoc prerequisites.
- //
- size_t busy (ctx.count_busy ());
- size_t exec (ctx.count_executed ());
-
- target_state rs (target_state::unchanged);
-
- wait_guard wg (ctx, busy, t[a].task_count);
-
- for (const target*& pt: t.prerequisite_targets[a])
- {
- if (pt == nullptr) // Skipped.
- continue;
-
- target_state s (execute_async (a, *pt, busy, t[a].task_count));
-
- if (s == target_state::postponed)
- {
- rs |= s;
- pt = nullptr;
- }
- }
-
- wg.wait ();
-
- bool e (mt == timestamp_nonexistent);
- for (prerequisite_target& p: t.prerequisite_targets[a])
- {
- if (p == nullptr)
- continue;
-
- const target& pt (*p.target);
-
- const auto& tc (pt[a].task_count);
- if (tc.load (memory_order_acquire) >= busy)
- ctx.sched.wait (exec, tc, scheduler::work_none);
-
- target_state s (pt.executed_state (a));
- rs |= s;
-
- // Compare our timestamp to this prerequisite's.
- //
- if (!e)
- {
- // If this is an mtime-based target, then compare timestamps.
- //
- if (const mtime_target* mpt = pt.is_a<mtime_target> ())
- {
- if (mpt->newer (mt, s))
- e = true;
- }
- else
- {
- // Otherwise we assume the prerequisite is newer if it was
- // changed.
- //
- if (s == target_state::changed)
- e = true;
- }
- }
-
- if (p.adhoc)
- p.target = nullptr; // Blank out.
-
- // As part of this loop calculate checksums that need to include ad
- // hoc prerequisites (unless the script tracks changes itself).
- //
- if (script.depdb_clear)
- continue;
-
- hash_target (pcs, pt);
-
- // The script can reference a program in one of four ways:
- //
- // 1. As an (imported) target (e.g., $cli)
- //
- // 2. As a process_path_ex (e.g., $cxx.path).
- //
- // 3. As a builtin (e.g., sed)
- //
- // 4. As a program path/name.
- //
- // When it comes to change tracking, there is nothing we can do for
- // (4) and there is nothing to do for (3) (assuming builtin semantics
- // is stable/backwards-compatible). The (2) case is handled
- // automatically by hashing all the variable values referenced by the
- // script (see below), which in case of process_path_ex includes the
- // checksum, if available.
- //
- // This leaves the (1) case, which itself splits into two sub-cases:
- // the target comes with the dependency information (e.g., imported
- // from a project via an export stub) or it does not (e.g., imported
- // as installed). We don't need to do anything extra for the first
- // sub-case since the target's state/mtime can be relied upon like any
- // other prerequisite. Which cannot be said about the second sub-case,
- // where we reply on checksum that may be included as part of the
- // target metadata.
- //
- // So what we are going to do is hash checksum metadata of every
- // executable prerequisite target that has it (we do it here in order
- // to include ad hoc prerequisites, which feels like the right thing
- // to do; the user may mark tools as ad hoc in order to omit them from
- // $<).
- //
- if (auto* e = pt.is_a<exe> ())
- {
- if (auto* c = e->lookup_metadata<string> ("checksum"))
- {
- ecs.append (*c);
- }
- }
- }
-
- if (!e)
- ps = rs;
- }
-
- bool update (!ps);
-
- // We use depdb to track changes to the script itself, input/output file
- // names, tools, etc.
- //
- depdb dd (tp + ".d");
-
- // First should come the rule name/version.
- //
- if (dd.expect ("<ad hoc buildscript recipe> 1") != nullptr)
- l4 ([&]{trace << "rule mismatch forcing update of " << t;});
-
- // Then the script checksum.
- //
- // Ideally, to detect changes to the script semantics, we would hash the
- // text with all the variables expanded but without executing any
- // commands. In practice, this is easier said than done (think the set
- // builtin that receives output of a command that modifies the
- // filesystem).
- //
- // So as the next best thing we are going to hash the unexpanded text as
- // well as values of all the variables expanded in it (which we get as a
- // side effect of pre-parsing the script). This approach has a number of
- // drawbacks:
- //
- // - We can't handle computed variable names (e.g., $($x ? X : Y)).
- //
- // - We may "overhash" by including variables that are actually
- // script-local.
- //
- // - There are functions like $install.resolve() with result based on
- // external (to the script) information.
- //
- if (dd.expect (checksum) != nullptr)
- l4 ([&]{trace << "recipe text change forcing update of " << t;});
-
- // Track the variables, targets, and prerequisites changes, unless the
- // script doesn't track the dependency changes itself.
- //
-
- // For each variable hash its name, undefined/null/non-null indicator,
- // and the value if non-null.
- //
- // Note that this excludes the special $< and $> variables which we
- // handle below.
- //
- if (!script.depdb_clear)
- {
- sha256 cs;
- names storage;
-
- for (const string& n: script.vars)
- {
- cs.append (n);
-
- lookup l;
-
- if (const variable* var = ctx.var_pool.find (n))
- l = t[var];
-
- cs.append (!l.defined () ? '\x1' : l->null ? '\x2' : '\x3');
-
- if (l)
- {
- storage.clear ();
- names_view ns (reverse (*l, storage));
-
- for (const name& n: ns)
- to_checksum (cs, n);
- }
- }
-
- if (dd.expect (cs.string ()) != nullptr)
- l4 ([&]{trace << "recipe variable change forcing update of " << t;});
- }
-
- // Target and prerequisite sets ($> and $<).
- //
- if (!script.depdb_clear)
- {
- auto hash = [ns = names ()] (sha256& cs, const target& t) mutable
- {
- if (const path_target* pt = t.is_a<path_target> ())
- cs.append (pt->path ().string ());
- else
- {
- ns.clear ();
- t.as_name (ns);
- for (const name& n: ns)
- to_checksum (cs, n);
- }
- };
-
- sha256 tcs;
- for (const target* m (&t); m != nullptr; m = m->adhoc_member)
- hash_target (tcs, *m);
-
- if (dd.expect (tcs.string ()) != nullptr)
- l4 ([&]{trace << "target set change forcing update of " << t;});
-
- if (dd.expect (pcs.string ()) != nullptr)
- l4 ([&]{trace << "prerequisite set change forcing update of " << t;});
- }
-
- // Finally the programs checksum.
- //
- if (!script.depdb_clear)
- {
- if (dd.expect (ecs.string ()) != nullptr)
- l4 ([&]{trace << "program checksum change forcing update of " << t;});
- }
-
- const scope* bs (nullptr);
- const scope* rs (nullptr);
-
- // Execute the custom dependency change tracking commands, if present.
- //
- if (!script.depdb_lines.empty ())
- {
- bs = &t.base_scope ();
- rs = bs->root_scope ();
-
- // While it would have been nice to reuse the environment for both
- // dependency tracking and execution, there are complications (creating
- // temporary directory, etc).
- //
- build::script::environment e (a, t, false /* temp_dir */);
- build::script::parser p (ctx);
-
- for (const script::line& l: script.depdb_lines)
- {
- names ns (p.execute_special (*rs, *bs, e, l));
-
- // These should have been enforced during pre-parsing.
- //
- assert (!ns.empty ()); // <cmd> ... <newline>
- assert (l.tokens.size () > 2); // 'depdb' <cmd> ... <newline>
-
- const string& cmd (ns[0].value);
-
- location loc (l.tokens[0].location ());
-
- if (cmd == "hash")
- {
- sha256 cs;
- for (auto i (ns.begin () + 1); i != ns.end (); ++i) // Skip <cmd>.
- to_checksum (cs, *i);
-
- if (dd.expect (cs.string ()) != nullptr)
- l4 ([&] {
- diag_record dr (trace);
- dr << "'depdb hash' argument change forcing update of " << t <<
- info (loc); script::dump (dr.os, l);
- });
- }
- else if (cmd == "string")
- {
- string s;
- try
- {
- s = convert<string> (names (make_move_iterator (ns.begin () + 1),
- make_move_iterator (ns.end ())));
- }
- catch (const invalid_argument& e)
- {
- fail (l.tokens[2].location ())
- << "invalid 'depdb string' argument: " << e;
- }
-
- if (dd.expect (s) != nullptr)
- l4 ([&] {
- diag_record dr (trace);
- dr << "'depdb string' argument change forcing update of "
- << t <<
- info (loc); script::dump (dr.os, l);
- });
- }
- else
- assert (false);
- }
- }
-
- // Update if depdb mismatch.
- //
- if (dd.writing () || dd.mtime > mt)
- update = true;
-
- dd.close ();
-
- // If nothing changed, then we are done.
- //
- if (!update)
- return *ps;
-
- if (!ctx.dry_run || verb != 0)
- {
- if (bs == nullptr)
- {
- bs = &t.base_scope ();
- rs = bs->root_scope ();
- }
-
- build::script::environment e (a, t, script.temp_dir);
- build::script::parser p (ctx);
-
- if (verb == 1)
- {
- if (script.diag_line)
- {
- text << p.execute_special (*rs, *bs, e, *script.diag_line);
- }
- else
- {
- // @@ TODO (and below):
- //
- // - we are printing target, not source (like in most other places)
- //
- // - printing of ad hoc target group (the {hxx cxx}{foo} idea)
- //
- // - if we are printing prerequisites, should we print all of them
- // (including tools)?
- //
- text << *script.diag_name << ' ' << t;
- }
- }
-
- if (!ctx.dry_run || verb >= 2)
- {
- build::script::default_runner r;
- p.execute (*rs, *bs, e, script, r);
-
- if (!ctx.dry_run)
- dd.check_mtime (tp);
- }
- }
-
- t.mtime (system_clock::now ());
- return target_state::changed;
- }
-
- target_state adhoc_script_rule::
- default_action (action a, const target& t) const
- {
- tracer trace ("adhoc_script_rule::default_action");
-
- context& ctx (t.ctx);
-
- execute_prerequisites (a, t);
-
- if (!ctx.dry_run || verb != 0)
- {
- const scope& bs (t.base_scope ());
- const scope& rs (*bs.root_scope ());
-
- build::script::environment e (a, t, script.temp_dir);
- build::script::parser p (ctx);
-
- if (verb == 1)
- {
- if (script.diag_line)
- {
- text << p.execute_special (rs, bs, e, *script.diag_line);
- }
- else
- {
- // @@ TODO: as above
- //
- text << *script.diag_name << ' ' << t;
- }
- }
-
- if (!ctx.dry_run || verb >= 2)
- {
- build::script::default_runner r;
- p.execute (rs, bs, e, script, r);
- }
- }
-
- return target_state::changed;
- }
-
- // cxx_rule_v1
- //
- bool cxx_rule_v1::
- match (action, target&, const string&) const
- {
- return true;
- }
-
- // adhoc_cxx_rule
- //
- adhoc_cxx_rule::
- adhoc_cxx_rule (const location& l, size_t b, uint64_t v, optional<string> s)
- : adhoc_rule ("<ad hoc c++ recipe>", l, b),
- version (v),
- separator (move (s)),
- impl (nullptr)
- {
- if (v != 1)
- fail (l) << "unsupported c++ recipe version " << v;
- }
-
- bool adhoc_cxx_rule::
- recipe_text (context&, const target&, string&& t, attributes&)
- {
- code = move (t);
- return true;
- }
-
- adhoc_cxx_rule::
- ~adhoc_cxx_rule ()
- {
- delete impl.load (memory_order_relaxed); // Serial execution.
- }
-
- void adhoc_cxx_rule::
- dump_text (ostream& os, string& ind) const
- {
- // @@ TODO: indentation is multi-line recipes is off (would need to insert
- // indentation after every newline).
- //
- os << ind << string (braces, '{') << " c++ " << version << endl
- << ind << code
- << ind << string (braces, '}');
- }
-
- // From module.cxx.
- //
- void
- create_module_context (context&, const location&);
-
- const target&
- update_in_module_context (context&, const scope&, names tgt,
- const location&, const path& bf);
-
- pair<void*, void*>
- load_module_library (const path& lib, const string& sym, string& err);
-
- bool adhoc_cxx_rule::
- match (action a, target& t, const string& hint) const
- {
- tracer trace ("adhoc_cxx_rule::match");
-
- context& ctx (t.ctx);
- const scope& rs (t.root_scope ());
-
- // The plan is to reduce this to the build system module case as much as
- // possible. Specifically, we switch to the load phase, create a module-
- // like library with the recipe text as a rule implementation, then build
- // and load it.
- //
- // Since the recipe can be shared among multiple targets, several threads
- // can all be trying to do this in parallel.
- //
- // We use the relaxed memory order here because any change must go through
- // the serial load phase. In other words, all we need here is atomicity
- // with ordering/visibility provided by the phase mutex.
- //
- cxx_rule* impl (this->impl.load (memory_order_relaxed));
-
- while (impl == nullptr) // Breakout loop.
- {
- // Switch the phase to (serial) load and re-check.
- //
- phase_switch ps (ctx, run_phase::load);
-
- if ((impl = this->impl.load (memory_order_relaxed)) != nullptr)
- break;
-
- using create_function = cxx_rule_v1* (const location&, target_state);
- using load_function = create_function* ();
-
- // The only way to guarantee that the name of our module matches its
- // implementation is to based the name on the implementation hash (plus
- // the language, in case we support other compiled implementations in
- // the future).
- //
- // Unfortunately, this means we will be creating a new project (and
- // leaving behind the old one as garbage) for every change to the
- // recipe. On the other hand, if the recipe is moved around unchanged,
- // we will reuse the same project. In fact, two different recipes (e.g.,
- // in different buildfiles) with the same text will share the project.
- //
- // The fact that we don't incorporate the recipe location into the hash
- // but include it in the source (in the form of the #line directive; see
- // below) has its own problems. If we do nothing extra here, then if a
- // "moved" but otherwise unchanged recipe is updated (for example,
- // because of changes in the build system core), then we may end up with
- // bogus location in the diagnostics.
- //
- // The straightforward solution would be to just update the location in
- // the source code if it has changed. This, however, will lead to
- // unnecessary and probably surprising recompilations since any line
- // count change before the recipe will trigger this update. One key
- // observation here is that we need accurate location information only
- // if we are going to recompile the recipe but the change to location
- // itself does not render the recipe out of date. So what we going to do
- // is factor the location information into its own small header and then
- // keep it up-to-date without changing its modification time.
- //
- // This works well if the project is not shared by multiple recipes.
- // However, if we have recipes in several buildfiles with identical
- // text, then the location information may end up yo-yo'ing depending on
- // which recipe got here first.
- //
- // There doesn't seem to be much we can do about it without incurring
- // other drawbacks/overheads. So the answer is for the user to use an ad
- // hoc rule with the common implementation instead of a bunch of
- // duplicate recipes.
- //
- string id;
- {
- sha256 cs;
- cs.append ("c++");
- cs.append (separator ? *separator : "");
- cs.append (code);
- id = cs.abbreviated_string (12);
- }
-
- dir_path pd (rs.out_path () /
- rs.root_extra->build_dir /
- recipes_build_dir /= id);
-
- path bf (pd / std_buildfile_file);
-
- string sym ("load_" + id);
-
- // Check whether the file exists and its last line matches the specified
- // signature.
- //
- // Note: we use the last instead of the first line for extra protection
- // against incomplete writes.
- //
- auto check_sig = [] (const path& f, const string& s) -> bool
- {
- try
- {
- if (!file_exists (f))
- return false;
-
- ifdstream ifs (f);
-
- string l;
- while (ifs.peek () != ifdstream::traits_type::eof ())
- getline (ifs, l);
-
- return l == s;
- }
- catch (const io_error& e)
- {
- fail << "unable to read " << f << ": " << e << endf;
- }
- catch (const system_error& e)
- {
- fail << "unable to access " << f << ": " << e << endf;
- }
- };
-
- // Calculate (and cache) the global/local fragments split.
- //
- struct fragments
- {
- size_t global_p; // Start position.
- size_t global_n; // Length (0 if no global fragment).
- location global_l; // Position.
-
- size_t local_p;
- size_t local_n;
- location local_l;
- };
-
- auto split = [this, f = optional<fragments> ()] () mutable ->
- const fragments&
- {
- if (f)
- return *f;
-
- // Note that the code starts from the next line thus +1.
- //
- location gl (loc.file, loc.line + 1, 1);
-
- if (!separator)
- {
- f = fragments {0, 0, location (), 0, code.size (), gl};
- return *f;
- }
-
- // Iterate over lines (keeping track of the current line) looking
- // for the separator.
- //
- uint64_t l (gl.line);
- for (size_t b (0), e (b), n (code.size ()); b < n; b = e + 1, l++)
- {
- if ((e = code.find ('\n', b)) == string::npos)
- e = n;
-
- // Trim the line.
- //
- size_t tb (b), te (e);
- auto ws = [] (char c) {return c == ' ' || c == '\t' || c == '\r';};
- for (; tb != te && ws (code[tb ]); ++tb) ;
- for (; te != tb && ws (code[te - 1]); --te) ;
-
- // text << "'" << string (code, tb, te - tb) << "'";
-
- if (code.compare (tb, te - tb, *separator) == 0)
- {
- // End the global fragment at the previous newline and start the
- // local fragment at the beginning of the next line.
- //
- location ll (loc.file, l + 1, 1);
-
- if (++e >= n)
- fail (ll) << "empty c++ recipe local fragment";
-
- f = fragments {0, b, gl, e, n - e, ll};
- return *f;
- }
- }
-
- fail (loc) << "c++ recipe fragment separator '" << *separator
- << "' not found" << endf;
- };
-
- bool nested (ctx.module_context == &ctx);
-
- // Create the build context if necessary.
- //
- if (ctx.module_context == nullptr)
- {
- if (!ctx.module_context_storage)
- fail (loc) << "unable to update ad hoc recipe for target " << t <<
- info << "building of ad hoc recipes is disabled";
-
- create_module_context (ctx, loc);
- }
-
- // "Switch" to the module context.
- //
- context& ctx (*t.ctx.module_context);
-
- const uint16_t verbosity (3); // Project creation command verbosity.
-
- // Project and location signatures.
- //
- // Specifically, we update the project version when changing anything
- // which would make the already existing projects unusable.
- //
- const string& lf (!loc.file.path.empty ()
- ? loc.file.path.string ()
- : loc.file.name ? *loc.file.name : string ());
-
- const string psig ("# c++ " + to_string (version));
- const string lsig ("// " + lf + ':' + to_string (loc.line));
-
- // Check whether we need to (re)create the project.
- //
- optional<bool> altn (false); // Standard naming scheme.
- bool create (!is_src_root (pd, altn));
-
- if (!create && (create = !check_sig (bf, psig)))
- rmdir_r (ctx, pd, false, verbosity); // Never dry-run.
-
- path of;
- ofdstream ofs;
-
- if (create)
- try
- {
- const fragments& frag (split ());
-
- // Write ad hoc config.build that loads the ~build2 configuration.
- // This way the configuration will be always in sync with ~build2
- // and we can update the recipe manually (e.g., for debugging).
- //
- create_project (
- pd,
- dir_path (), /* amalgamation */
- {}, /* boot_modules */
- "cxx.std = latest", /* root_pre */
- {"cxx."}, /* root_modules */
- "", /* root_post */
- string ("config"), /* config_module */
- string ("config.config.load = ~build2"), /* config_file */
- false, /* buildfile */
- "build2 core", /* who */
- verbosity); /* verbosity */
-
-
- // Write the rule source file.
- //
- of = path (pd / "rule.cxx");
-
- if (verb >= verbosity)
- text << (verb >= 2 ? "cat >" : "save ") << of;
-
- ofs.open (of);
-
- ofs << "#include \"location.hxx\"" << '\n'
- << '\n';
-
- // Include every header that can plausibly be needed by a rule.
- //
- // @@ TMP: any new headers to add? [Keep this note for review.]
- //
- ofs << "#include <libbuild2/types.hxx>" << '\n'
- << "#include <libbuild2/forward.hxx>" << '\n'
- << "#include <libbuild2/utility.hxx>" << '\n'
- << '\n'
- << "#include <libbuild2/file.hxx>" << '\n'
- << "#include <libbuild2/rule.hxx>" << '\n'
- << "#include <libbuild2/depdb.hxx>" << '\n'
- << "#include <libbuild2/scope.hxx>" << '\n'
- << "#include <libbuild2/target.hxx>" << '\n'
- << "#include <libbuild2/context.hxx>" << '\n'
- << "#include <libbuild2/variable.hxx>" << '\n'
- << "#include <libbuild2/algorithm.hxx>" << '\n'
- << "#include <libbuild2/filesystem.hxx>" << '\n'
- << "#include <libbuild2/diagnostics.hxx>" << '\n'
- << '\n';
-
- // Write the global fragment, if any. Note that it always includes the
- // trailing newline.
- //
- if (frag.global_n != 0)
- {
- // Use the #line directive to point diagnostics to the code in the
- // buildfile. Note that there is no easy way to restore things to
- // point back to the source file (other than another #line with a
- // line and a file). Let's not bother for now.
- //
- ofs << "#line RECIPE_GLOBAL_LINE RECIPE_FILE" << '\n';
- ofs.write (code.c_str () + frag.global_p, frag.global_n);
- ofs << '\n';
- }
-
- // Normally the recipe code will have one level of indentation so
- // let's not indent the namespace level to match.
- //
- ofs << "namespace build2" << '\n'
- << "{" << '\n'
- << '\n';
-
- // If we want the user to be able to supply a custom constuctor, then
- // we have to give the class a predictable name (i.e., we cannot use
- // id as part of its name) and put it into an unnamed namespace. One
- // clever idea is to call the class `constructor` but the name could
- // also be used for a custom destructor (still could work) or for name
- // qualification (would definitely look bizarre).
- //
- // In this light the most natural name is probable `rule`. The issue
- // is we already have this name in the build2 namespace (and its our
- // indirect base). In fact, any name that we choose could in the
- // future conflict with something in that namespace so maybe it makes
- // sense to bite the bullet and pick a name that is least likely to be
- // used by the user directly (can always use cxx_rule instead).
- //
- ofs << "namespace" << '\n'
- << "{" << '\n'
- << "class rule: public cxx_rule_v1" << '\n'
- << "{" << '\n'
- << "public:" << '\n'
- << '\n';
-
- // Inherit base constructor. This way the user may provide their own
- // but don't have to.
- //
- ofs << " using cxx_rule_v1::cxx_rule_v1;" << '\n'
- << '\n';
-
- // An extern "C" function cannot throw which can happen in case of a
- // user-defined constructor. So we need an extra level of indirection.
- // We incorporate id to make sure it doesn't conflict with anything
- // user-defined.
- //
- ofs << " static cxx_rule_v1*" << '\n'
- << " create_" << id << " (const location& l, target_state s)" << '\n'
- << " {" << '\n'
- << " return new rule (l, s);" << '\n'
- << " }" << '\n'
- << '\n';
-
- // Use the #line directive to point diagnostics to the code in the
- // buildfile similar to the global fragment above.
- //
- ofs << "#line RECIPE_LOCAL_LINE RECIPE_FILE" << '\n';
-
- // Note that the local fragment always includes the trailing newline.
- //
- ofs.write (code.c_str () + frag.local_p, frag.local_n);
- ofs << "};" << '\n'
- << '\n';
-
- // Add an alias that we can use unambiguously in the load function.
- //
- ofs << "using rule_" << id << " = rule;" << '\n'
- << "}" << '\n'
- << '\n';
-
- // Entry point.
- //
- ofs << "extern \"C\"" << '\n'
- << "#ifdef _WIN32" << '\n'
- << "__declspec(dllexport)" << '\n'
- << "#endif" << '\n'
- << "cxx_rule_v1* (*" << sym << " ()) (const location&, target_state)" << '\n'
- << "{" << '\n'
- << " return &rule_" << id << "::create_" << id << ";" << '\n'
- << "}" << '\n'
- << '\n';
-
- ofs << "}" << '\n';
-
- ofs.close ();
-
-
- // Write buildfile.
- //
- of = bf;
-
- if (verb >= verbosity)
- text << (verb >= 2 ? "cat >" : "save ") << of;
-
- ofs.open (of);
-
- ofs << "import imp_libs += build2%lib{build2}" << '\n'
- << "libs{" << id << "}: cxx{rule} hxx{location} $imp_libs" << '\n'
- << '\n'
- << psig << '\n';
-
- ofs.close ();
- }
- catch (const io_error& e)
- {
- fail << "unable to write to " << of << ": " << e;
- }
-
- // Update the library target in the module context.
- //
- const target* l (nullptr);
- do // Breakout loop.
- {
- // Load the project in the module context.
- //
- // Note that it's possible it has already been loaded (see above about
- // the id calculation).
- //
- scope& rs (load_project (ctx, pd, pd, false /* forwarded */));
-
- auto find_target = [&ctx, &rs, &pd, &id] ()
- {
- const target_type* tt (rs.find_target_type ("libs"));
- assert (tt != nullptr);
-
- const target* t (
- ctx.targets.find (*tt, pd, dir_path () /* out */, id));
- assert (t != nullptr);
-
- return t;
- };
-
- // If the project has already been loaded then, as an optimization,
- // check if the target has already been updated (this will make a
- // difference we if we have identical recipes in several buildfiles,
- // especially to the location update that comes next).
- //
- if (!source_once (rs, rs, bf))
- {
- l = find_target ();
-
- if (l->executed_state (perform_update_id) != target_state::unknown)
- break;
- }
-
- // Create/update the recipe location header.
- //
- // For update, preserve the file timestamp in order not to render the
- // recipe out of date.
- //
- of = path (pd / "location.hxx");
- if (!check_sig (of, lsig))
- try
- {
- const fragments& frag (split ());
-
- entry_time et (file_time (of));
-
- if (verb >= verbosity)
- text << (verb >= 2 ? "cat >" : "save ") << of;
-
- ofs.open (of);
-
- // Recipe file and line for the #line directive above. We also need
- // to escape backslashes (Windows paths).
- //
- ofs << "#define RECIPE_FILE \"" << sanitize_strlit (lf) << '"'<< '\n';
-
- if (frag.global_n != 0)
- ofs << "#define RECIPE_GLOBAL_LINE " << frag.global_l.line << '\n';
-
- ofs << "#define RECIPE_LOCAL_LINE " << frag.local_l.line << '\n'
- << '\n'
- << lsig << '\n';
-
- ofs.close ();
-
- if (et.modification != timestamp_nonexistent)
- file_time (of, et);
- }
- catch (const io_error& e)
- {
- fail << "unable to write to " << of << ": " << e;
- }
- catch (const system_error& e)
- {
- fail << "unable to get/set timestamp for " << of << ": " << e;
- }
-
- if (nested)
- {
- // This means there is a perform update action already in progress
- // in this context. So we are going to switch the phase and
- // perform direct match and update (similar how we do this for
- // generated headers).
- //
- // Note that since neither match nor execute are serial phases, it
- // means other targets in this context can be matched and executed
- // in paralellel with us.
- //
- if (l == nullptr)
- l = find_target ();
-
- phase_switch mp (ctx, run_phase::match);
- if (build2::match (perform_update_id, *l) != target_state::unchanged)
- {
- phase_switch ep (ctx, run_phase::execute);
- execute (a, *l);
- }
- }
- else
- {
- // Cutoff the existing diagnostics stack and push our own entry.
- //
- diag_frame::stack_guard diag_cutoff (nullptr);
-
- auto df = make_diag_frame (
- [this, &t] (const diag_record& dr)
- {
- dr << info (loc) << "while updating ad hoc recipe for target "
- << t;
- });
-
- l = &update_in_module_context (
- ctx, rs, names {name (pd, "libs", id)},
- loc, bf);
- }
- } while (false);
-
- // Load the library.
- //
- const path& lib (l->as<file> ().path ());
-
- // Note again that it's possible the library has already been loaded
- // (see above about the id calculation).
- //
- string err;
- pair<void*, void*> hs (load_module_library (lib, sym, err));
-
- // These normally shouldn't happen unless something is seriously broken.
- //
- if (hs.first == nullptr)
- fail (loc) << "unable to load recipe library " << lib << ": " << err;
-
- if (hs.second == nullptr)
- fail (loc) << "unable to lookup " << sym << " in recipe library "
- << lib << ": " << err;
-
- {
- auto df = make_diag_frame (
- [this](const diag_record& dr)
- {
- if (verb != 0)
- dr << info (loc) << "while initializing ad hoc recipe";
- });
-
- load_function* lf (function_cast<load_function*> (hs.second));
- create_function* cf (lf ());
-
- impl = cf (loc, l->executed_state (perform_update_id));
- this->impl.store (impl, memory_order_relaxed); // Still in load phase.
- }
- }
-
- return impl->match (a, t, hint);
- }
-
- recipe adhoc_cxx_rule::
- apply (action a, target& t) const
- {
- return impl.load (memory_order_relaxed)->apply (a, t);
- }
}