24 files changed, 192 insertions, 78 deletions
diff --git a/bootstrap-mingw.bat b/bootstrap-mingw.bat
index 5061753..e4caf8e 100644
--- a/bootstrap-mingw.bat
+++ b/bootstrap-mingw.bat
@@ -65,7 +65,6 @@ set "src=%src% build2\bin"
 set "src=%src% build2\c"
 set "src=%src% build2\cc"
 set "src=%src% build2\cxx"
-set "src=%src% build2\version"
 
 set "src=%src% libbuild2"
 set "src=%src% libbuild2\config"
@@ -73,6 +72,7 @@ set "src=%src% libbuild2\dist"
 set "src=%src% libbuild2\test"
 set "src=%src% libbuild2\test\script"
 set "src=%src% libbuild2\install"
+set "src=%src% libbuild2\version"
 set "src=%src% libbuild2\in"
 
 set "src=%src% %libbutl%\libbutl"
diff --git a/bootstrap-msvc.bat b/bootstrap-msvc.bat
index e4e2a66..1facca5 100644
--- a/bootstrap-msvc.bat
+++ b/bootstrap-msvc.bat
@@ -96,7 +96,6 @@ set "src=%src% build2\bin"
 set "src=%src% build2\c"
 set "src=%src% build2\cc"
 set "src=%src% build2\cxx"
-set "src=%src% build2\version"
 
 set "src=%src% libbuild2"
 set "src=%src% libbuild2\config"
@@ -104,6 +103,7 @@ set "src=%src% libbuild2\dist"
 set "src=%src% libbuild2\test"
 set "src=%src% libbuild2\test\script"
 set "src=%src% libbuild2\install"
+set "src=%src% libbuild2\version"
 set "src=%src% libbuild2\in"
 
 set "src=%src% %libbutl%\libbutl"
diff --git a/bootstrap.gmake b/bootstrap.gmake
index 793f3d0..e4d4b33 100644
--- a/bootstrap.gmake
+++ b/bootstrap.gmake
@@ -133,8 +133,7 @@ build2_sub := \
 bin           \
 c             \
 cc            \
-cxx           \
-version
+cxx
 
 libbuild2_sub := \
 config           \
@@ -142,6 +141,7 @@ dist             \
 test/script      \
 test             \
 install          \
+version          \
 in
 
 build2_src    := $(wildcard $(src_root)/build2/*.cxx)
diff --git a/bootstrap.sh b/bootstrap.sh
index 7e754b0..8de5e3c 100755
--- a/bootstrap.sh
+++ b/bootstrap.sh
@@ -122,7 +122,6 @@ src="$src build2/c/*.cxx"
 src="$src build2/cc/*.cxx"
 src="$src build2/cxx/*.cxx"
 src="$src build2/cli/*.cxx"
-src="$src build2/version/*.cxx"
 src="$src build2/bash/*.cxx"
 
 src="$src libbuild2/*.cxx"
@@ -131,6 +130,7 @@ src="$src libbuild2/dist/*.cxx"
 src="$src libbuild2/test/*.cxx"
 src="$src libbuild2/test/script/*.cxx"
 src="$src libbuild2/install/*.cxx"
+src="$src libbuild2/version/*.cxx"
 src="$src libbuild2/in/*.cxx"
 
 src="$src $libbutl/libbutl/*.cxx"
diff --git a/build2/b.cxx b/build2/b.cxx
index 907784b..a016278 100644
--- a/build2/b.cxx
+++ b/build2/b.cxx
@@ -52,7 +52,7 @@
 #include <libbuild2/install/init.hxx>
 
 #include <libbuild2/in/init.hxx>
-#include <build2/version/init.hxx>
+#include <libbuild2/version/init.hxx>
 
 #include <build2/bin/init.hxx>
 #include <build2/c/init.hxx>
@@ -449,8 +449,7 @@ main (int argc, char* argv[])
       reg (&test::build2_test_load);
       reg (&install::build2_install_load);
 
-      bm["version"] = mf {"version", &version::boot, &version::init};
-
+      reg (&version::build2_version_load);
       reg (&in::build2_in_load);
 
       bm["bin.vars"] = mf {"bin.vars", nullptr, &bin::vars_init};
diff --git a/build2/bash/init.cxx b/build2/bash/init.cxx
index a23bc61..146e680 100644
--- a/build2/bash/init.cxx
+++ b/build2/bash/init.cxx
@@ -36,7 +36,7 @@ namespace build2
       tracer trace ("bash::init");
       l5 ([&]{trace << "for " << bs;});
 
-      // Load in.base (in.* varibales, in{} target type).
+      // Load in.base (in.* variables, in{} target type).
       //
       if (!cast_false<bool> (rs["in.base.loaded"]))
         load_module (rs, rs, "in.base", l);
diff --git a/build2/buildfile b/build2/buildfile
index a940793..ea39e87 100644
--- a/build2/buildfile
+++ b/build2/buildfile
@@ -8,9 +8,9 @@ import libs += libpkgconf%lib{pkgconf}
 include ../libbuild2/
 libs += ../libbuild2/lib{build2}
 
-for m: in
+for m: version in
 {
-  include ../libbuild2/in/
+  include ../libbuild2/$m/
   libs += ../libbuild2/$m/lib{build2-$m}
 }
 
diff --git a/build2/version/init.hxx b/build2/version/init.hxx
deleted file mode 100644
index ef3688a..0000000
--- a/build2/version/init.hxx
+++ /dev/null
@@ -1,31 +0,0 @@
-// file      : build2/version/init.hxx -*- C++ -*-
-// copyright : Copyright (c) 2014-2019 Code Synthesis Ltd
-// license   : MIT; see accompanying LICENSE file
-
-#ifndef BUILD2_VERSION_INIT_HXX
-#define BUILD2_VERSION_INIT_HXX
-
-#include <libbuild2/types.hxx>
-#include <libbuild2/utility.hxx>
-
-#include <libbuild2/module.hxx>
-
-namespace build2
-{
-  namespace version
-  {
-    bool
-    boot (scope&, const location&, unique_ptr<module_base>&);
-
-    bool
-    init (scope&,
-          scope&,
-          const location&,
-          unique_ptr<module_base>&,
-          bool,
-          bool,
-          const variable_map&);
-  }
-}
-
-#endif // BUILD2_VERSION_INIT_HXX
diff --git a/libbuild2/buildfile b/libbuild2/buildfile
index b015d21..ab95098 100644
--- a/libbuild2/buildfile
+++ b/libbuild2/buildfile
@@ -2,7 +2,7 @@
 # copyright : Copyright (c) 2014-2019 Code Synthesis Ltd
 # license   : MIT; see accompanying LICENSE file
 
-./: lib{build2} in/
+./: lib{build2} version/ in/
 
 import int_libs = libbutl%lib{butl}
 
diff --git a/libbuild2/version/buildfile b/libbuild2/version/buildfile
new file mode 100644
index 0000000..e9d4905
--- /dev/null
+++ b/libbuild2/version/buildfile
@@ -0,0 +1,66 @@
+# file      : libbuild2/version/buildfile
+# copyright : Copyright (c) 2014-2019 Code Synthesis Ltd
+# license   : MIT; see accompanying LICENSE file
+
+import int_libs = libbutl%lib{butl}
+
+include ../
+int_libs += ../lib{build2}
+
+include ../in/
+int_libs += ../in/lib{build2-in}
+
+./: lib{build2-version}: libul{build2-version}: \
+  {hxx ixx txx cxx}{** -**.test...}             \
+  $int_libs
+
+# Unit tests.
+#
+exe{*.test}:
+{
+  test = true
+  install = false
+}
+
+for t: cxx{**.test...}
+{
+  d = $directory($t)
+  n = $name($t)...
+
+  ./: $d/exe{$n}: $t $d/{hxx ixx txx}{+$n} $d/testscript{+$n}
+  $d/exe{$n}: libul{build2-version}: bin.whole = false
+}
+
+# Build options.
+#
+obja{*}: cxx.poptions += -DLIBBUILD2_VERSION_STATIC_BUILD
+objs{*}: cxx.poptions += -DLIBBUILD2_VERSION_SHARED_BUILD
+
+# Export options.
+#
+lib{build2-version}:
+{
+  cxx.export.poptions = "-I$out_root" "-I$src_root"
+  cxx.export.libs = $int_libs
+}
+
+liba{build2-version}: cxx.export.poptions += -DLIBBUILD2_VERSION_STATIC
+libs{build2-version}: cxx.export.poptions += -DLIBBUILD2_VERSION_SHARED
+
+# For pre-releases use the complete version to make sure they cannot be used
+# in place of another pre-release or the final version. See the version module
+# for details on the version.* variable values.
+#
+if $version.pre_release
+  lib{build2-version}: bin.lib.version = @"-$version.project_id"
+else
+  lib{build2-version}: bin.lib.version = @"-$version.major.$version.minor"
+
+# Install into the libbuild2/version/ subdirectory of, say, /usr/include/
+# recreating subdirectories.
+#
+{hxx ixx txx}{*}:
+{
+  install         = include/libbuild2/version/
+  install.subdirs = true
+}
diff --git a/libbuild2/version/export.hxx b/libbuild2/version/export.hxx
new file mode 100644
index 0000000..c76cd8a
--- /dev/null
+++ b/libbuild2/version/export.hxx
@@ -0,0 +1,34 @@
+#pragma once
+
+// Normally we don't export class templates (but do complete specializations),
+// inline functions, and classes with only inline member functions. Exporting
+// classes that inherit from non-exported/imported bases (e.g., std::string)
+// will end up badly. The only known workarounds are to not inherit or to not
+// export. Also, MinGW GCC doesn't like seeing non-exported functions being
+// used before their inline definition. The workaround is to reorder code. In
+// the end it's all trial and error.
+
+#if defined(LIBBUILD2_VERSION_STATIC)         // Using static.
+#  define LIBBUILD2_VERSION_SYMEXPORT
+#elif defined(LIBBUILD2_VERSION_STATIC_BUILD) // Building static.
+#  define LIBBUILD2_VERSION_SYMEXPORT
+#elif defined(LIBBUILD2_VERSION_SHARED)       // Using shared.
+#  ifdef _WIN32
+#    define LIBBUILD2_VERSION_SYMEXPORT __declspec(dllimport)
+#  else
+#    define LIBBUILD2_VERSION_SYMEXPORT
+#  endif
+#elif defined(LIBBUILD2_VERSION_SHARED_BUILD) // Building shared.
+#  ifdef _WIN32
+#    define LIBBUILD2_VERSION_SYMEXPORT __declspec(dllexport)
+#  else
+#    define LIBBUILD2_VERSION_SYMEXPORT
+#  endif
+#else
+// If none of the above macros are defined, then we assume we are being used
+// by some third-party build system that cannot/doesn't signal the library
+// type. Note that this fallback works for both static and shared but in case
+// of shared will be sub-optimal compared to having dllimport.
+//
+#  define LIBBUILD2_VERSION_SYMEXPORT         // Using static or shared.
+#endif
diff --git a/build2/version/init.cxx b/libbuild2/version/init.cxx
index 30f0f45..8adbb29 100644
--- a/build2/version/init.cxx
+++ b/libbuild2/version/init.cxx
@@ -1,8 +1,8 @@
-// file      : build2/version/init.cxx -*- C++ -*-
+// file      : libbuild2/version/init.cxx -*- C++ -*-
 // copyright : Copyright (c) 2014-2019 Code Synthesis Ltd
 // license   : MIT; see accompanying LICENSE file
 
-#include <build2/version/init.hxx>
+#include <libbuild2/version/init.hxx>
 
 #include <libbutl/manifest-parser.mxx>
 
@@ -15,10 +15,10 @@
 
 #include <libbuild2/dist/module.hxx>
 
-#include <build2/version/rule.hxx>
-#include <build2/version/module.hxx>
-#include <build2/version/utility.hxx>
-#include <build2/version/snapshot.hxx>
+#include <libbuild2/version/rule.hxx>
+#include <libbuild2/version/module.hxx>
+#include <libbuild2/version/utility.hxx>
+#include <libbuild2/version/snapshot.hxx>
 
 using namespace std;
 using namespace butl;
@@ -295,7 +295,7 @@ namespace build2
       if (!first)
         fail (l) << "multiple version module initializations";
 
-      // Load in.base (in.* varibales, in{} target type).
+      // Load in.base (in.* variables, in{} target type).
       //
       if (!cast_false<bool> (rs["in.base.loaded"]))
         load_module (rs, rs, "in.base", l);
@@ -388,5 +388,20 @@ namespace build2
         fail << "unable to overwrite " << f << ": " << e;
       }
     }
+
+    static const module_functions mod_functions[] =
+    {
+      // NOTE: don't forget to also update the documentation in init.hxx if
+      //       changing anything here.
+
+      {"version", boot,    init},
+      {nullptr,   nullptr, nullptr}
+    };
+
+    const module_functions*
+    build2_version_load ()
+    {
+      return mod_functions;
+    }
   }
 }
diff --git a/libbuild2/version/init.hxx b/libbuild2/version/init.hxx
new file mode 100644
index 0000000..68e4def
--- /dev/null
+++ b/libbuild2/version/init.hxx
@@ -0,0 +1,28 @@
+// file      : libbuild2/version/init.hxx -*- C++ -*-
+// copyright : Copyright (c) 2014-2019 Code Synthesis Ltd
+// license   : MIT; see accompanying LICENSE file
+
+#ifndef LIBBUILD2_VERSION_INIT_HXX
+#define LIBBUILD2_VERSION_INIT_HXX
+
+#include <libbuild2/types.hxx>
+#include <libbuild2/utility.hxx>
+
+#include <libbuild2/module.hxx>
+
+#include <libbuild2/version/export.hxx>
+
+namespace build2
+{
+  namespace version
+  {
+    // Module `version` requires bootstrapping.
+    //
+    // No submodules.
+    //
+    extern "C" LIBBUILD2_VERSION_SYMEXPORT const module_functions*
+    build2_version_load ();
+  }
+}
+
+#endif // LIBBUILD2_VERSION_INIT_HXX
diff --git a/build2/version/module.cxx b/libbuild2/version/module.cxx
index 1811cfc..5ee44f7 100644
--- a/build2/version/module.cxx
+++ b/libbuild2/version/module.cxx
@@ -1,8 +1,8 @@
-// file      : build2/version/module.cxx -*- C++ -*-
+// file      : libbuild2/version/module.cxx -*- C++ -*-
 // copyright : Copyright (c) 2014-2019 Code Synthesis Ltd
 // license   : MIT; see accompanying LICENSE file
 
-#include <build2/version/module.hxx>
+#include <libbuild2/version/module.hxx>
 
 using namespace std;
 
diff --git a/build2/version/module.hxx b/libbuild2/version/module.hxx
index d2b681c..174da7b 100644
--- a/build2/version/module.hxx
+++ b/libbuild2/version/module.hxx
@@ -1,9 +1,9 @@
-// file      : build2/version/module.hxx -*- C++ -*-
+// file      : libbuild2/version/module.hxx -*- C++ -*-
 // copyright : Copyright (c) 2014-2019 Code Synthesis Ltd
 // license   : MIT; see accompanying LICENSE file
 
-#ifndef BUILD2_VERSION_MODULE_HXX
-#define BUILD2_VERSION_MODULE_HXX
+#ifndef LIBBUILD2_VERSION_MODULE_HXX
+#define LIBBUILD2_VERSION_MODULE_HXX
 
 #include <map>
 
@@ -61,4 +61,4 @@ namespace build2
   }
 }
 
-#endif // BUILD2_VERSION_MODULE_HXX
+#endif // LIBBUILD2_VERSION_MODULE_HXX
diff --git a/build2/version/rule.cxx b/libbuild2/version/rule.cxx
index f110e3e..37e6b0f 100644
--- a/build2/version/rule.cxx
+++ b/libbuild2/version/rule.cxx
@@ -1,8 +1,8 @@
-// file      : build2/version/rule.cxx -*- C++ -*-
+// file      : libbuild2/version/rule.cxx -*- C++ -*-
 // copyright : Copyright (c) 2014-2019 Code Synthesis Ltd
 // license   : MIT; see accompanying LICENSE file
 
-#include <build2/version/rule.hxx>
+#include <libbuild2/version/rule.hxx>
 
 #include <libbuild2/scope.hxx>
 #include <libbuild2/target.hxx>
@@ -10,8 +10,8 @@
 
 #include <libbuild2/in/target.hxx>
 
-#include <build2/version/module.hxx>
-#include <build2/version/utility.hxx>
+#include <libbuild2/version/module.hxx>
+#include <libbuild2/version/utility.hxx>
 
 using namespace std;
 using namespace butl;
diff --git a/build2/version/rule.hxx b/libbuild2/version/rule.hxx
index 7bfb783..ce21aa4 100644
--- a/build2/version/rule.hxx
+++ b/libbuild2/version/rule.hxx
@@ -1,9 +1,9 @@
-// file      : build2/version/rule.hxx -*- C++ -*-
+// file      : libbuild2/version/rule.hxx -*- C++ -*-
 // copyright : Copyright (c) 2014-2019 Code Synthesis Ltd
 // license   : MIT; see accompanying LICENSE file
 
-#ifndef BUILD2_VERSION_RULE_HXX
-#define BUILD2_VERSION_RULE_HXX
+#ifndef LIBBUILD2_VERSION_RULE_HXX
+#define LIBBUILD2_VERSION_RULE_HXX
 
 #include <libbuild2/types.hxx>
 #include <libbuild2/utility.hxx>
@@ -49,4 +49,4 @@ namespace build2
   }
 }
 
-#endif // BUILD2_VERSION_RULE_HXX
+#endif // LIBBUILD2_VERSION_RULE_HXX
diff --git a/build2/version/snapshot-git.cxx b/libbuild2/version/snapshot-git.cxx
index f7993d2..b7ca084 100644
--- a/build2/version/snapshot-git.cxx
+++ b/libbuild2/version/snapshot-git.cxx
@@ -1,4 +1,4 @@
-// file      : build2/version/snapshot-git.cxx -*- C++ -*-
+// file      : libbuild2/version/snapshot-git.cxx -*- C++ -*-
 // copyright : Copyright (c) 2014-2019 Code Synthesis Ltd
 // license   : MIT; see accompanying LICENSE file
 
@@ -6,7 +6,7 @@
 
 #include <libbutl/sha1.mxx>
 
-#include <build2/version/snapshot.hxx>
+#include <libbuild2/version/snapshot.hxx>
 
 using namespace std;
 using namespace butl;
diff --git a/build2/version/snapshot.cxx b/libbuild2/version/snapshot.cxx
index b43e083..46b37f3 100644
--- a/build2/version/snapshot.cxx
+++ b/libbuild2/version/snapshot.cxx
@@ -1,8 +1,8 @@
-// file      : build2/version/snapshot.cxx -*- C++ -*-
+// file      : libbuild2/version/snapshot.cxx -*- C++ -*-
 // copyright : Copyright (c) 2014-2019 Code Synthesis Ltd
 // license   : MIT; see accompanying LICENSE file
 
-#include <build2/version/snapshot.hxx>
+#include <libbuild2/version/snapshot.hxx>
 
 #include <libbuild2/filesystem.hxx>
 
diff --git a/build2/version/snapshot.hxx b/libbuild2/version/snapshot.hxx
index 824ec89..86b6eab 100644
--- a/build2/version/snapshot.hxx
+++ b/libbuild2/version/snapshot.hxx
@@ -1,9 +1,9 @@
-// file      : build2/version/snapshot.hxx -*- C++ -*-
+// file      : libbuild2/version/snapshot.hxx -*- C++ -*-
 // copyright : Copyright (c) 2014-2019 Code Synthesis Ltd
 // license   : MIT; see accompanying LICENSE file
 
-#ifndef BUILD2_VERSION_SNAPSHOT_HXX
-#define BUILD2_VERSION_SNAPSHOT_HXX
+#ifndef LIBBUILD2_VERSION_SNAPSHOT_HXX
+#define LIBBUILD2_VERSION_SNAPSHOT_HXX
 
 #include <libbuild2/types.hxx>
 #include <libbuild2/utility.hxx>
@@ -31,4 +31,4 @@ namespace build2
   }
 }
 
-#endif // BUILD2_VERSION_SNAPSHOT_HXX
+#endif // LIBBUILD2_VERSION_SNAPSHOT_HXX
diff --git a/build2/version/utility.cxx b/libbuild2/version/utility.cxx
index 8286ff8..c93a251 100644
--- a/build2/version/utility.cxx
+++ b/libbuild2/version/utility.cxx
@@ -1,8 +1,8 @@
-// file      : build2/version/utility.cxx -*- C++ -*-
+// file      : libbuild2/version/utility.cxx -*- C++ -*-
 // copyright : Copyright (c) 2014-2019 Code Synthesis Ltd
 // license   : MIT; see accompanying LICENSE file
 
-#include <build2/version/utility.hxx>
+#include <libbuild2/version/utility.hxx>
 
 #include <libbutl/manifest-parser.mxx>
 #include <libbutl/manifest-serializer.mxx>
diff --git a/build2/version/utility.hxx b/libbuild2/version/utility.hxx
index 83bb91c..16e8c78 100644
--- a/build2/version/utility.hxx
+++ b/libbuild2/version/utility.hxx
@@ -1,9 +1,9 @@
-// file      : build2/version/utility.hxx -*- C++ -*-
+// file      : libbuild2/version/utility.hxx -*- C++ -*-
 // copyright : Copyright (c) 2014-2019 Code Synthesis Ltd
 // license   : MIT; see accompanying LICENSE file
 
-#ifndef BUILD2_VERSION_UTILITY_HXX
-#define BUILD2_VERSION_UTILITY_HXX
+#ifndef LIBBUILD2_VERSION_UTILITY_HXX
+#define LIBBUILD2_VERSION_UTILITY_HXX
 
 #include <libbuild2/types.hxx>
 #include <libbuild2/utility.hxx>
@@ -22,4 +22,4 @@ namespace build2
   }
 }
 
-#endif // BUILD2_VERSION_UTILITY_HXX
+#endif // LIBBUILD2_VERSION_UTILITY_HXX
diff --git a/tests/libbuild2/buildfile b/tests/libbuild2/buildfile
index 51b2f5b..aa6c17f 100644
--- a/tests/libbuild2/buildfile
+++ b/tests/libbuild2/buildfile
@@ -4,6 +4,7 @@
 
 import libs  = build2%lib{build2}
 import libs += build2%lib{build2-in}
+import libs += build2%lib{build2-version}
 
 exe{driver}: {hxx cxx}{*} $libs testscript
 
diff --git a/tests/libbuild2/driver.cxx b/tests/libbuild2/driver.cxx
index d9c086a..544d43e 100644
--- a/tests/libbuild2/driver.cxx
+++ b/tests/libbuild2/driver.cxx
@@ -9,6 +9,7 @@
 #include <libbuild2/scheduler.hxx>
 
 #include <libbuild2/in/init.hxx>
+#include <libbuild2/version/init.hxx>
 
 using namespace build2;
 
@@ -20,6 +21,7 @@ main (int, char* argv[])
   init_diag (1);
   init (argv[0]);
 
+  version::build2_version_load ();
   in::build2_in_load ();
 
   sched.startup (1);  // Serial execution.