Initial system package manager infrastructure

8 files changed, 141 insertions, 30 deletions

diff --git a/bpkg/bpkg.cxx b/bpkg/bpkg.cxx
index 3ede99e..76b2533 100644
--- a/bpkg/bpkg.cxx
+++ b/bpkg/bpkg.cxx
@@ -611,6 +611,7 @@ try
     cout << "bpkg " << BPKG_VERSION_ID << endl
          << "libbpkg " << LIBBPKG_VERSION_ID << endl
          << "libbutl " << LIBBUTL_VERSION_ID << endl
+         << "host " << host_triplet << endl
          << "Copyright (c) " << BPKG_COPYRIGHT << "." << endl
          << "This is free software released under the MIT license." << endl;
     return 0;
diff --git a/bpkg/buildfile b/bpkg/buildfile
index b3b2ba7..ca78218 100644
--- a/bpkg/buildfile
+++ b/bpkg/buildfile
@@ -97,8 +97,10 @@ for t: cxx{**.test...}
 
 # Build options.
 #
-obj{utility}: cxx.poptions += -DBPKG_EXE_PREFIX='"'$bin.exe.prefix'"' \
--DBPKG_EXE_SUFFIX='"'$bin.exe.suffix'"'
+obj{utility}: cxx.poptions += \
+"-DBPKG_EXE_PREFIX=\"$bin.exe.prefix\"" \
+"-DBPKG_EXE_SUFFIX=\"$bin.exe.suffix\"" \
+"-DBPKG_HOST_TRIPLET=\"$cxx.target\""
 
 # Pass the copyright notice extracted from the LICENSE file.
 #
@@ -107,7 +109,7 @@ copyright = $process.run_regex(                                 \
   'Copyright \(c\) (.+) \(see the AUTHORS and LEGAL files\)\.', \
   '\1')
 
-obj{bpkg}: cxx.poptions += -DBPKG_COPYRIGHT=\"$copyright\"
+obj{bpkg}: cxx.poptions += "-DBPKG_COPYRIGHT=\"$copyright\""
 
 # Disable "unknown pragma" warnings.
 #
diff --git a/bpkg/pkg-build.cxx b/bpkg/pkg-build.cxx
index aa34594..437e080 100644
--- a/bpkg/pkg-build.cxx
+++ b/bpkg/pkg-build.cxx
@@ -32,7 +32,9 @@
 #include <bpkg/pkg-disfigure.hxx>
 #include <bpkg/package-query.hxx>
 #include <bpkg/package-skeleton.hxx>
+
 #include <bpkg/system-repository.hxx>
+#include <bpkg/system-package-manager.hxx>
 
 #include <bpkg/pkg-build-collect.hxx>
 
@@ -1652,23 +1654,68 @@ namespace bpkg
       return r;
     };
 
-    // Add the system package authoritative information to the database's
-    // system repository, unless it already contains authoritative information
-    // for this package.
+    // Figure out the system package version unless explicitly specified and
+    // add the system package authoritative information to the database's
+    // system repository unless the database is NULL or it already contains
+    // authoritative information for this package. Return the figured out
+    // system package version as constraint.
     //
     // Note that it is assumed that all the possible duplicates are handled
     // elsewhere/later.
     //
-    auto add_system_package = [] (database& db,
-                                  const package_name& nm,
-                                  const version& v)
+    auto add_system_package =
+      [spm = optional<unique_ptr<system_package_manager>> ()] // Create lazy.
+      (database* db,
+       const package_name& nm,
+       optional<version_constraint> vc) mutable
     {
-      assert (db.system_repository);
+      if (!vc)
+      {
+        // @@ Where do we check that this package should have available_
+        //    package (source or stub)? We will need to drag all such
+        //    available packages into this call in order to get the
+        //    name/version mappings.
 
-      const system_package* sp (db.system_repository->find (nm));
+        // See if we should query the system package manager.
+        //
+        // @@ TODO: --sys-no-query
+        //
+        if (!spm)
+          spm = /*ops.sys_no_query ()*/ false
+            ? nullptr
+            : make_system_package_manager (host_triplet, "" /* type */);
 
-      if (sp == nullptr || !sp->authoritative)
-        db.system_repository->insert (nm, v, true /* authoritative */);
+        if (*spm != nullptr)
+        {
+          // @@ TODO: query the version
+          //
+          //system_package_manager& m (**spm);
+        }
+        else
+          vc = version_constraint (wildcard_version);
+      }
+      else
+        // The system package may only have an exact/wildcard version
+        // specified.
+        //
+        assert (vc->min_version == vc->max_version);
+
+      if (db != nullptr)
+      {
+        assert (db->system_repository);
+
+        const system_package* sp (db->system_repository->find (nm));
+
+        if (sp == nullptr || !sp->authoritative)
+          db->system_repository->insert (nm,
+                                         *vc->min_version,
+                                         true /* authoritative */);
+
+        // @@ If it is authoritative, wouldn't it be a good idea to check that
+        //    the versions match?
+      }
+
+      return vc;
     };
 
     // Create the parsed package argument. Issue diagnostics and fail if the
@@ -1707,17 +1754,7 @@ namespace bpkg
       {
       case package_scheme::sys:
         {
-          if (!r.constraint)
-            r.constraint = version_constraint (wildcard_version);
-
-          // The system package may only have an exact/wildcard version
-          // specified.
-          //
-          assert (r.constraint->min_version == r.constraint->max_version);
-
-          if (db != nullptr)
-            add_system_package (*db, r.name, *r.constraint->min_version);
-
+          r.constraint = add_system_package (db, r.name, move (r.constraint));
           break;
         }
       case package_scheme::none: break; // Nothing to do.
@@ -3180,12 +3217,7 @@ namespace bpkg
           // The system package may only have an exact/wildcard version
           // specified.
           //
-          add_system_package (db,
-                              p.name,
-                              (p.constraint
-                               ? *p.constraint->min_version
-                               : wildcard_version));
-
+          add_system_package (&db, p.name, p.constraint);
           enter (db, p);
         };
 
diff --git a/bpkg/system-package-manager.cxx b/bpkg/system-package-manager.cxx
new file mode 100644
index 0000000..1503c32
--- /dev/null
+++ b/bpkg/system-package-manager.cxx
@@ -0,0 +1,31 @@
+// file      : bpkg/system-package-manager.cxx -*- C++ -*-
+// license   : MIT; see accompanying LICENSE file
+
+#include <bpkg/system-package-manager.hxx>
+
+#include <bpkg/diagnostics.hxx>
+
+namespace bpkg
+{
+  system_package_manager::
+  ~system_package_manager ()
+  {
+    // vtable
+  }
+
+  unique_ptr<system_package_manager>
+  make_system_package_manager (const target_triplet& host,
+                               const string& type)
+  {
+    unique_ptr<system_package_manager> r;
+
+    if (r == nullptr)
+    {
+      if (!type.empty ())
+        fail << "unsupported package manager type '" << type << "' for host "
+             << host;
+    }
+
+    return r;
+  }
+}
diff --git a/bpkg/system-package-manager.hxx b/bpkg/system-package-manager.hxx
new file mode 100644
index 0000000..122b181
--- /dev/null
+++ b/bpkg/system-package-manager.hxx
@@ -0,0 +1,34 @@
+// file      : bpkg/system-package-manager.hxx -*- C++ -*-
+// license   : MIT; see accompanying LICENSE file
+
+#ifndef BPKG_SYSTEM_PACKAGE_MANAGER_HXX
+#define BPKG_SYSTEM_PACKAGE_MANAGER_HXX
+
+//#include <libbpkg/manifest.hxx>     // version
+//#include <libbpkg/package-name.hxx>
+
+#include <bpkg/types.hxx>
+#include <bpkg/utility.hxx>
+
+namespace bpkg
+{
+  // The system package manager interface. Used by both pkg-build (to query
+  // and install system packages) and by pkg-bindist (to build them).
+  //
+  class system_package_manager
+  {
+  public:
+    virtual
+    ~system_package_manager ();
+  };
+
+  // Create a package manager instance corresponding to the specified host
+  // target and optional manager type. If type is empty, return NULL if there
+  // is no support for this platform.
+  //
+  unique_ptr<system_package_manager>
+  make_system_package_manager (const target_triplet&,
+                               const string& type);
+}
+
+#endif // BPKG_SYSTEM_PACKAGE_MANAGER_HXX
diff --git a/bpkg/types.hxx b/bpkg/types.hxx
index 2b6a1f8..7a7b2c7 100644
--- a/bpkg/types.hxx
+++ b/bpkg/types.hxx
@@ -33,6 +33,7 @@
 #include <libbutl/optional.hxx>
 #include <libbutl/fdstream.hxx>
 #include <libbutl/small-vector.hxx>
+#include <libbutl/target-triplet.hxx>
 #include <libbutl/default-options.hxx>
 
 namespace bpkg
@@ -127,6 +128,10 @@ namespace bpkg
   using butl::ofdstream;
   using butl::fdstream_mode;
 
+  // <libbutl/target-triplet.hxx>
+  //
+  using butl::target_triplet;
+
   // <libbutl/default-options.hxx>
   //
   using butl::default_options_files;
diff --git a/bpkg/utility.cxx b/bpkg/utility.cxx
index 52114df..b79c85b 100644
--- a/bpkg/utility.cxx
+++ b/bpkg/utility.cxx
@@ -46,6 +46,8 @@ namespace bpkg
 
   const dir_path current_dir (".");
 
+  const target_triplet host_triplet (BPKG_HOST_TRIPLET);
+
   map<dir_path, dir_path> tmp_dirs;
 
   bool keep_tmp;
diff --git a/bpkg/utility.hxx b/bpkg/utility.hxx
index 8e7260a..04c7c94 100644
--- a/bpkg/utility.hxx
+++ b/bpkg/utility.hxx
@@ -99,6 +99,10 @@ namespace bpkg
 
   extern const dir_path current_dir;        // ./
 
+  // Host target triplet for which we were built.
+  //
+  extern const target_triplet host_triplet;
+
   // Temporary directory facility.
   //
   // An entry normally maps <cfg-dir> to <cfg-dir>/.bpkg/tmp/ but can also map