Add pkg-config support for import installed

Redesign library importing/exporting while at it.

2 files changed, 196 insertions, 0 deletions

diff --git a/build2/pkgconfig/init b/build2/pkgconfig/init
new file mode 100644
index 0000000..53821ae
--- /dev/null
+++ b/build2/pkgconfig/init
@@ -0,0 +1,37 @@
+// file      : build2/pkgconfig/init -*- C++ -*-
+// copyright : Copyright (c) 2014-2016 Code Synthesis Ltd
+// license   : MIT; see accompanying LICENSE file
+
+#ifndef BUILD2_PKGCONFIG_INIT
+#define BUILD2_PKGCONFIG_INIT
+
+#include <build2/types>
+#include <build2/utility>
+
+#include <build2/module>
+
+namespace build2
+{
+  namespace pkgconfig
+  {
+    bool
+    config_init (scope&,
+                 scope&,
+                 const location&,
+                 unique_ptr<module_base>&,
+                 bool,
+                 bool,
+                 const variable_map&);
+
+    bool
+    init (scope&,
+          scope&,
+          const location&,
+          unique_ptr<module_base>&,
+          bool,
+          bool,
+          const variable_map&);
+  }
+}
+
+#endif // BUILD2_PKGCONFIG_INIT
diff --git a/build2/pkgconfig/init.cxx b/build2/pkgconfig/init.cxx
new file mode 100644
index 0000000..b7100e3
--- /dev/null
+++ b/build2/pkgconfig/init.cxx
@@ -0,0 +1,159 @@
+// file      : build2/pkgconfig/init.cxx -*- C++ -*-
+// copyright : Copyright (c) 2014-2016 Code Synthesis Ltd
+// license   : MIT; see accompanying LICENSE file
+
+#include <build2/pkgconfig/init>
+
+#include <build2/scope>
+#include <build2/target>
+#include <build2/variable>
+#include <build2/diagnostics>
+
+#include <build2/config/utility>
+
+using namespace std;
+using namespace butl;
+
+namespace build2
+{
+  namespace pkgconfig
+  {
+    bool
+    config_init (scope& rs,
+                 scope& bs,
+                 const location& l,
+                 unique_ptr<module_base>&,
+                 bool,
+                 bool optional,
+                 const variable_map& hints)
+    {
+      tracer trace ("pkgconfig::config_init");
+      l5 ([&]{trace << "for " << bs.out_path ();});
+
+      if (&rs != &bs)
+        fail (l) << "pkgconfig.config loaded for non-root scope";
+
+      // Enter variables.
+      //
+      // config.pkgconfig.target is a hint.
+      //
+      auto& vp (var_pool);
+
+      const variable& c_x (vp.insert<path> ("config.pkgconfig", true));
+      const variable& c_x_tgt (vp.insert<string> ("config.pkgconfig.target"));
+      const variable& x_path (vp.insert<process_path> ("pkgconfig.path"));
+
+      // Configure.
+      //
+
+      // Adjust module priority (between compilers and binutils).
+      //
+      config::save_module (rs, "pkgconfig", 325);
+
+      process_path pp;
+      bool new_val (false); // Set any new values?
+
+      auto p (config::omitted (rs, c_x));
+
+      if (const value* v = p.first)
+      {
+        const path& x (cast<path> (*v));
+
+        try
+        {
+          // If this is a user-specified value, then it's non-optional.
+          //
+          pp = process::path_search (x, true);
+          new_val = p.second;
+        }
+        catch (const process_error& e)
+        {
+          fail << "unable to execute " << x << ": " << e.what ();
+        }
+      }
+
+      string d; // Default name (pp.initial may be its shallow copy).
+
+      // If we have a target hint, then next try <triplet>-pkg-config.
+      //
+      if (pp.empty ())
+      {
+        if (const string* t = cast_null<string> (hints[c_x_tgt]))
+        {
+          d = *t;
+          d += "-pkg-config";
+
+          l5 ([&]{trace << "trying " << d;});
+          pp = process::try_path_search (d, true);
+        }
+      }
+
+      // Finallly, try just pkg-config.
+      //
+      if (pp.empty ())
+      {
+        d = "pkg-config";
+
+        l5 ([&]{trace << "trying " << d;});
+        pp = process::try_path_search (d, true);
+      }
+
+      bool conf (!pp.empty ());
+
+      if (!conf && !optional)
+        fail (l) << "unable to find pkg-config program";
+
+      // Config report.
+      //
+      if (verb >= (new_val ? 2 : 3))
+      {
+        diag_record dr (text);
+        dr << "pkgconfig " << project (rs) << '@' << rs.out_path () << '\n';
+
+        if (conf)
+          dr << "  pkg-config " << pp;
+        else
+          dr << "  pkg-config " << "not found, leaving unconfigured";
+      }
+
+      if (conf)
+        rs.assign (x_path) = move (pp);
+
+      return conf;
+    }
+
+    bool
+    init (scope& rs,
+          scope& bs,
+          const location& loc,
+          unique_ptr<module_base>&,
+          bool,
+          bool optional,
+          const variable_map& hints)
+    {
+      tracer trace ("pkgconfig::init");
+      l5 ([&]{trace << "for " << bs.out_path ();});
+
+      // Load pkgconfig.config.
+      //
+      if (!cast_false<bool> (rs["pkgconfig.config.loaded"]))
+      {
+        if (!load_module ("pkgconfig.config", rs, rs, loc, optional, hints))
+          return false;
+      }
+      else if (!cast_false<bool> (rs["pkgconfig.config.configured"]))
+      {
+        if (!optional)
+          fail << "pkgconfig module could not be configured" <<
+            info << "re-run with -V option for more information";
+
+        return false;
+      }
+
+      // For now pkgconfig and pkgconfig.config is pretty much the same.
+      //
+
+      return true;
+    }
+  }
+}