Move cli module to libbuild2-cli library

This is a temporary measure (until we unboundle this module) needed for
in-process configure support in bpkg.

1 files changed, 340 insertions, 0 deletions

diff --git a/libbuild2/cli/rule.cxx b/libbuild2/cli/rule.cxx
new file mode 100644
index 0000000..996ca51
--- /dev/null
+++ b/libbuild2/cli/rule.cxx
@@ -0,0 +1,340 @@
+// file      : libbuild2/cli/rule.cxx -*- C++ -*-
+// license   : MIT; see accompanying LICENSE file
+
+#include <libbuild2/cli/rule.hxx>
+
+#include <libbuild2/depdb.hxx>
+#include <libbuild2/scope.hxx>
+#include <libbuild2/target.hxx>
+#include <libbuild2/context.hxx>
+#include <libbuild2/algorithm.hxx>
+#include <libbuild2/filesystem.hxx>
+#include <libbuild2/diagnostics.hxx>
+
+#include <libbuild2/cli/target.hxx>
+
+namespace build2
+{
+  namespace cli
+  {
+    // Figure out if name contains stem and, optionally, calculate prefix and
+    // suffix.
+    //
+    static bool
+    match_stem (const string& name, const string& stem,
+                string* prefix = nullptr, string* suffix = nullptr)
+    {
+      size_t p (name.find (stem));
+
+      if (p != string::npos)
+      {
+        if (prefix != nullptr)
+          prefix->assign (name, 0, p);
+
+        if (suffix != nullptr)
+          suffix->assign (name, p + stem.size (), string::npos);
+
+        return true;
+      }
+
+      return false;
+    }
+
+    bool compile_rule::
+    match (action a, target& t) const
+    {
+      tracer trace ("cli::compile_rule::match");
+
+      // Find the .cli source file.
+      //
+      auto find = [&trace, a, &t] (auto&& r) -> optional<prerequisite_member>
+      {
+        for (prerequisite_member p: r)
+        {
+          // 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<cli> ())
+          {
+            // Check that the stem match.
+            //
+            if (match_stem (t.name, p.name ()))
+              return p;
+
+            l4 ([&]{trace << ".cli file stem '" << p.name () << "' "
+                          << "doesn't match target " << t;});
+          }
+        }
+
+        return nullopt;
+      };
+
+      if (cli_cxx* pt = t.is_a<cli_cxx> ())
+      {
+        // The cli.cxx{} group.
+        //
+        cli_cxx& t (*pt);
+
+        // See if we have a .cli source file.
+        //
+        if (!find (group_prerequisite_members (a, t)))
+        {
+          l4 ([&]{trace << "no .cli source file for target " << t;});
+          return false;
+        }
+
+        // Figure out the member list.
+        //
+        // At this stage, no further changes to cli.options are possible and
+        // we can determine whether the --suppress-inline option is present.
+        //
+        // Passing the group as a "reference target" is a bit iffy,
+        // conceptually.
+        //
+        t.h = &search<cxx::hxx> (t, t.dir, t.out, t.name);
+        t.c = &search<cxx::cxx> (t, t.dir, t.out, t.name);
+        t.i = find_option ("--suppress-inline", t, "cli.options")
+          ? nullptr
+          : &search<cxx::ixx> (t, t.dir, t.out, t.name);
+
+        return true;
+      }
+      else
+      {
+        // One of the ?xx{} members.
+        //
+
+        // Check if there is a corresponding cli.cxx{} group.
+        //
+        const cli_cxx* g (t.ctx.targets.find<cli_cxx> (t.dir, t.out, t.name));
+
+        // If not or if it has no prerequisites (happens when we use it to
+        // set cli.options) and this target has a cli{} prerequisite, then
+        // synthesize the dependency.
+        //
+        if (g == nullptr || !g->has_prerequisites ())
+        {
+          if (optional<prerequisite_member> p = find (
+                prerequisite_members (a, t)))
+          {
+            if (g == nullptr)
+              g = &t.ctx.targets.insert<cli_cxx> (t.dir, t.out, t.name, trace);
+
+            prerequisites ps;
+            ps.push_back (p->as_prerequisite ());
+            g->prerequisites (move (ps));
+          }
+        }
+
+        if (g == nullptr)
+          return false;
+
+        // For ixx{}, verify it is part of the group (i.e., not disabled
+        // via --suppress-inline).
+        //
+        if (t.is_a<cxx::ixx> () &&
+            find_option ("--suppress-inline", *g, "cli.options"))
+          return false;
+
+        t.group = g;
+        return true;
+      }
+    }
+
+    recipe compile_rule::
+    apply (action a, target& xt) const
+    {
+      if (cli_cxx* pt = xt.is_a<cli_cxx> ())
+      {
+        cli_cxx& t (*pt);
+
+        // Derive file names for the members.
+        //
+        t.h->derive_path ();
+        t.c->derive_path ();
+        if (t.i != nullptr)
+          t.i->derive_path ();
+
+        // Inject dependency on the output directory.
+        //
+        inject_fsdir (a, t);
+
+        // Match prerequisites.
+        //
+        match_prerequisite_members (a, t);
+
+        // For update inject dependency on the CLI compiler target.
+        //
+        if (a == perform_update_id)
+          inject (a, t, ctgt);
+
+        switch (a)
+        {
+        case perform_update_id: return [this] (action a, const target& t)
+          {
+            return perform_update (a, t);
+          };
+        case perform_clean_id:  return &perform_clean_group_depdb;
+        default:                return noop_recipe; // Configure/dist update.
+        }
+      }
+      else
+      {
+        const cli_cxx& g (xt.group->as<cli_cxx> ());
+        match_sync (a, g);
+        return group_recipe; // Execute the group's recipe.
+      }
+    }
+
+    static void
+    append_extension (cstrings& args,
+                      const path_target& t,
+                      const char* option,
+                      const char* default_extension)
+    {
+      const string* e (t.ext ());
+      assert (e != nullptr); // Should have been figured out in apply().
+
+      if (*e != default_extension)
+      {
+        // CLI needs the extension with the leading dot (unless it is empty)
+        // while we store the extension without. But if there is an extension,
+        // then we can get it (with the dot) from the file name.
+        //
+        args.push_back (option);
+        args.push_back (e->empty ()
+                        ? e->c_str ()
+                        : t.path ().extension_cstring () - 1);
+      }
+    }
+
+    target_state compile_rule::
+    perform_update (action a, const target& xt) const
+    {
+      tracer trace ("cli::compile_rule::perform_update");
+
+      // The rule has been matched which means the members should be resolved
+      // and paths assigned. We use the header file as our "target path" for
+      // timestamp, depdb, etc.
+      //
+      const cli_cxx& t (xt.as<cli_cxx> ());
+      const path& tp (t.h->path ());
+
+      context& ctx (t.ctx);
+
+      // Update prerequisites and determine if any relevant ones render us
+      // out-of-date. Note that currently we treat all the prerequisites as
+      // potentially affecting the result (think prologues/epilogues, CLI
+      // compiler target itself, etc).
+      //
+      timestamp mt (t.load_mtime (tp));
+      auto pr (execute_prerequisites<cli> (a, t, mt));
+
+      bool update (!pr.first);
+      target_state ts (update ? target_state::changed : *pr.first);
+
+      const cli& s (pr.second);
+
+      // We use depdb to track changes to the .cli file name, options,
+      // compiler, etc.
+      //
+      depdb dd (tp + ".d");
+      {
+        // First should come the rule name/version.
+        //
+        if (dd.expect ("cli.compile 1") != nullptr)
+          l4 ([&]{trace << "rule mismatch forcing update of " << t;});
+
+        // Then the compiler checksum.
+        //
+        if (dd.expect (csum) != nullptr)
+          l4 ([&]{trace << "compiler mismatch forcing update of " << t;});
+
+        // Then the options checksum.
+        //
+        sha256 cs;
+        append_options (cs, t, "cli.options");
+
+        if (dd.expect (cs.string ()) != nullptr)
+          l4 ([&]{trace << "options mismatch forcing update of " << t;});
+
+        // Finally the .cli input file.
+        //
+        if (dd.expect (s.path ()) != nullptr)
+          l4 ([&]{trace << "input file mismatch forcing update of " << t;});
+      }
+
+      // Update if depdb mismatch.
+      //
+      if (dd.writing () || dd.mtime > mt)
+        update = true;
+
+      dd.close ();
+
+      // If nothing changed, then we are done.
+      //
+      if (!update)
+        return ts;
+
+      // Translate paths to relative (to working directory). This results in
+      // easier to read diagnostics.
+      //
+      path relo (relative (t.dir));
+      path rels (relative (s.path ()));
+
+      const process_path& pp (ctgt.process_path ());
+      cstrings args {pp.recall_string ()};
+
+      // See if we need to pass --output-{prefix,suffix}
+      //
+      string prefix, suffix;
+      match_stem (t.name, s.name, &prefix, &suffix);
+
+      if (!prefix.empty ())
+      {
+        args.push_back ("--output-prefix");
+        args.push_back (prefix.c_str ());
+      }
+
+      if (!suffix.empty ())
+      {
+        args.push_back ("--output-suffix");
+        args.push_back (suffix.c_str ());
+      }
+
+      // See if we need to pass any --?xx-suffix options.
+      //
+      append_extension (args, *t.h, "--hxx-suffix", "hxx");
+      append_extension (args, *t.c, "--cxx-suffix", "cxx");
+      if (t.i != nullptr)
+        append_extension (args, *t.i, "--ixx-suffix", "ixx");
+
+      append_options (args, t, "cli.options");
+
+      if (!relo.empty ())
+      {
+        args.push_back ("-o");
+        args.push_back (relo.string ().c_str ());
+      }
+
+      args.push_back (rels.string ().c_str ());
+      args.push_back (nullptr);
+
+      if (verb >= 2)
+        print_process (args);
+      else if (verb)
+        print_diag ("cli", s, t);
+
+      if (!ctx.dry_run)
+      {
+        run (ctx, pp, args, 1 /* finish_verbosity */);
+        dd.check_mtime (tp);
+      }
+
+      t.mtime (system_clock::now ());
+      return target_state::changed;
+    }
+  }
+}