Move c build system module to separate library

16 files changed, 196 insertions, 68 deletions

diff --git a/bootstrap-mingw.bat b/bootstrap-mingw.bat
index fc3c9ff..43cc84f 100644
--- a/bootstrap-mingw.bat
+++ b/bootstrap-mingw.bat
@@ -61,7 +61,6 @@ if "_%libbutl%_" == "__" (
 rem All the source directories.
 rem
 set "src=build2"
-set "src=%src% build2\c"
 set "src=%src% build2\cxx"
 
 set "src=%src% libbuild2"
@@ -71,6 +70,7 @@ set "src=%src% libbuild2\test"
 set "src=%src% libbuild2\test\script"
 set "src=%src% libbuild2\install"
 set "src=%src% libbuild2\bin"
+set "src=%src% libbuild2\c"
 set "src=%src% libbuild2\cc"
 set "src=%src% libbuild2\version"
 set "src=%src% libbuild2\in"
diff --git a/bootstrap-msvc.bat b/bootstrap-msvc.bat
index 7526b0c..8da8769 100644
--- a/bootstrap-msvc.bat
+++ b/bootstrap-msvc.bat
@@ -92,7 +92,6 @@ if "_%libbutl%_" == "__" (
 rem All the source directories.
 rem
 set "src=build2"
-set "src=%src% build2\c"
 set "src=%src% build2\cxx"
 
 set "src=%src% libbuild2"
@@ -102,6 +101,7 @@ set "src=%src% libbuild2\test"
 set "src=%src% libbuild2\test\script"
 set "src=%src% libbuild2\install"
 set "src=%src% libbuild2\bin"
+set "src=%src% libbuild2\c"
 set "src=%src% libbuild2\cc"
 set "src=%src% libbuild2\version"
 set "src=%src% libbuild2\in"
diff --git a/bootstrap.gmake b/bootstrap.gmake
index 0cafedf..0e3126e 100644
--- a/bootstrap.gmake
+++ b/bootstrap.gmake
@@ -130,7 +130,6 @@ endif
 # Note: list nested subdirectories first (used in clean).
 #
 build2_sub := \
-c             \
 cxx
 
 libbuild2_sub := \
@@ -140,6 +139,7 @@ test/script      \
 test             \
 install          \
 bin              \
+c                \
 cc               \
 version          \
 in
diff --git a/bootstrap.sh b/bootstrap.sh
index f227d82..368a549 100755
--- a/bootstrap.sh
+++ b/bootstrap.sh
@@ -117,7 +117,6 @@ if test -z "$libbutl"; then
 fi
 
 src="build2/*.cxx"
-src="$src build2/c/*.cxx"
 src="$src build2/cxx/*.cxx"
 
 src="$src libbuild2/*.cxx"
@@ -127,6 +126,7 @@ src="$src libbuild2/test/*.cxx"
 src="$src libbuild2/test/script/*.cxx"
 src="$src libbuild2/install/*.cxx"
 src="$src libbuild2/bin/*.cxx"
+src="$src libbuild2/c/*.cxx"
 src="$src libbuild2/cc/*.cxx"
 src="$src libbuild2/version/*.cxx"
 src="$src libbuild2/in/*.cxx"
diff --git a/build2/b.cxx b/build2/b.cxx
index be67a8c..1fd6b5a 100644
--- a/build2/b.cxx
+++ b/build2/b.cxx
@@ -54,6 +54,7 @@
 
 #include <libbuild2/in/init.hxx>
 #include <libbuild2/bin/init.hxx>
+#include <libbuild2/c/init.hxx>
 #include <libbuild2/cc/init.hxx>
 #include <libbuild2/version/init.hxx>
 
@@ -63,7 +64,6 @@
 #  include <build2/cli/init.hxx>
 #endif
 
-#include <build2/c/init.hxx>
 #include <build2/cxx/init.hxx>
 
 using namespace butl;
@@ -521,13 +521,10 @@ main (int argc, char* argv[])
 
       load (&bin::build2_bin_load);
       load (&cc::build2_cc_load);
+      load (&c::build2_c_load);
       load (&version::build2_version_load);
       load (&in::build2_in_load);
 
-      TMP_LOAD (c_guess, "c.guess", c::guess_init);
-      TMP_LOAD (c_config, "c.config", c::config_init);
-      TMP_LOAD (c, "c", c::init);
-
       TMP_LOAD (cxx_guess, "cxx.guess", cxx::guess_init);
       TMP_LOAD (cxx_config, "cxx.config", cxx::config_init);
       TMP_LOAD (cxx, "cxx", cxx::init);
diff --git a/build2/buildfile b/build2/buildfile
index cfc46e5..7f4187e 100644
--- a/build2/buildfile
+++ b/build2/buildfile
@@ -7,7 +7,7 @@ import libs = libbutl%lib{butl}
 include ../libbuild2/
 libs += ../libbuild2/lib{build2}
 
-for m: bash bin cc in version
+for m: bash bin c cc in version
 {
   include ../libbuild2/$m/
   libs += ../libbuild2/$m/lib{build2-$m}
@@ -48,9 +48,6 @@ obj{b}: cxx.poptions += -DBUILD2_HOST_TRIPLET=\"$cxx.target\"
 #
 if ($cxx.target == $build.host)
 {
-  c/obj{init}: cxx.poptions += \
-    -DBUILD2_NATIVE_C=\"$regex.replace($recall($c.path), '\\', '\\\\')\"
-
   cxx/obj{init}: cxx.poptions += \
     -DBUILD2_NATIVE_CXX=\"$regex.replace($recall($cxx.path), '\\', '\\\\')\"
 }
diff --git a/build2/c/init.hxx b/build2/c/init.hxx
deleted file mode 100644
index 77119a9..0000000
--- a/build2/c/init.hxx
+++ /dev/null
@@ -1,46 +0,0 @@
-// file      : build2/c/init.hxx -*- C++ -*-
-// copyright : Copyright (c) 2014-2019 Code Synthesis Ltd
-// license   : MIT; see accompanying LICENSE file
-
-#ifndef BUILD2_C_INIT_HXX
-#define BUILD2_C_INIT_HXX
-
-#include <libbuild2/types.hxx>
-#include <libbuild2/utility.hxx>
-
-#include <libbuild2/module.hxx>
-
-namespace build2
-{
-  namespace c
-  {
-    bool
-    guess_init (scope&,
-                scope&,
-                const location&,
-                unique_ptr<module_base>&,
-                bool,
-                bool,
-                const variable_map&);
-
-    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_C_INIT_HXX
diff --git a/libbuild2/buildfile b/libbuild2/buildfile
index aad4e78..75731fc 100644
--- a/libbuild2/buildfile
+++ b/libbuild2/buildfile
@@ -5,7 +5,7 @@
 # NOTE: remember to update bundled_modules in libbuild2/modules.cxx if adding
 #       a new module.
 #
-./: lib{build2} bash/ bin/ cc/ in/ version/
+./: lib{build2} bash/ bin/ c/ cc/ in/ version/
 
 import int_libs = libbutl%lib{butl}
 
diff --git a/libbuild2/c/buildfile b/libbuild2/c/buildfile
new file mode 100644
index 0000000..39a5d7a
--- /dev/null
+++ b/libbuild2/c/buildfile
@@ -0,0 +1,90 @@
+# file      : libbuild2/c/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 ../cc/
+int_libs += ../cc/lib{build2-cc}
+
+./: lib{build2-c}: libul{build2-c}: {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-c}: bin.whole = false
+}
+
+# Build options.
+#
+obja{*}: cxx.poptions += -DLIBBUILD2_C_STATIC_BUILD
+objs{*}: cxx.poptions += -DLIBBUILD2_C_SHARED_BUILD
+
+# Note that we used to compare complete target triplets but that proved too
+# strict (see libbuild2/buildfile for details).
+#
+cross = ($cxx.target.cpu != $build.host.cpu || \
+         $cxx.target.system != $build.host.system)
+
+# Pass native C compiler path (not forgetting to escape backslashes on
+# Windows). It is used as defaults for BUILD2_DEFAULT_C.
+#
+if! $cross
+{
+  obj{init}: cxx.poptions += \
+    -DBUILD2_NATIVE_C=\"$regex.replace($recall($c.path), '\\', '\\\\')\"
+
+  obja{init}: cxx.poptions += -DLIBBUILD2_C_STATIC_BUILD
+  objs{init}: cxx.poptions += -DLIBBUILD2_C_SHARED_BUILD
+}
+
+# Export options.
+#
+lib{build2-c}:
+{
+  cxx.export.poptions = "-I$out_root" "-I$src_root"
+  cxx.export.libs = $int_libs
+}
+
+liba{build2-c}: cxx.export.poptions += -DLIBBUILD2_C_STATIC
+libs{build2-c}: cxx.export.poptions += -DLIBBUILD2_C_SHARED
+
+# For pre-releases use the complete version to make sure they cannot be used
+# in place of another pre-release or the final version. See the version module
+# for details on the version.* variable values.
+#
+# And because this is a build system module, we also embed the same value as
+# the interface version (note that we cannot use build.version.interface for
+# bundled modules because we could be built with a different version of the
+# build system).
+#
+ver = ($version.pre_release    \
+       ? "$version.project_id" \
+       : "$version.major.$version.minor")
+
+lib{build2-c}: bin.lib.version = @"-$ver"
+libs{build2-c}: bin.lib.load_suffix = "-$ver"
+
+# Install into the libbuild2/c/ subdirectory of, say, /usr/include/
+# recreating subdirectories.
+#
+{hxx ixx txx}{*}:
+{
+  install         = include/libbuild2/c/
+  install.subdirs = true
+}
diff --git a/libbuild2/c/export.hxx b/libbuild2/c/export.hxx
new file mode 100644
index 0000000..6fe3203
--- /dev/null
+++ b/libbuild2/c/export.hxx
@@ -0,0 +1,38 @@
+// file      : libbuild2/c/export.hxx -*- C++ -*-
+// copyright : Copyright (c) 2014-2019 Code Synthesis Ltd
+// license   : MIT; see accompanying LICENSE file
+
+#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_C_STATIC)         // Using static.
+#  define LIBBUILD2_C_SYMEXPORT
+#elif defined(LIBBUILD2_C_STATIC_BUILD) // Building static.
+#  define LIBBUILD2_C_SYMEXPORT
+#elif defined(LIBBUILD2_C_SHARED)       // Using shared.
+#  ifdef _WIN32
+#    define LIBBUILD2_C_SYMEXPORT __declspec(dllimport)
+#  else
+#    define LIBBUILD2_C_SYMEXPORT
+#  endif
+#elif defined(LIBBUILD2_C_SHARED_BUILD) // Building shared.
+#  ifdef _WIN32
+#    define LIBBUILD2_C_SYMEXPORT __declspec(dllexport)
+#  else
+#    define LIBBUILD2_C_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_C_SYMEXPORT         // Using static or shared.
+#endif
diff --git a/build2/c/init.cxx b/libbuild2/c/init.cxx
index 6d271a7..43d647f 100644
--- a/build2/c/init.cxx
+++ b/libbuild2/c/init.cxx
@@ -1,8 +1,8 @@
-// file      : build2/c/init.cxx -*- C++ -*-
+// file      : libbuild2/c/init.cxx -*- C++ -*-
 // copyright : Copyright (c) 2014-2019 Code Synthesis Ltd
 // license   : MIT; see accompanying LICENSE file
 
-#include <build2/c/init.hxx>
+#include <libbuild2/c/init.hxx>
 
 #include <libbuild2/scope.hxx>
 #include <libbuild2/diagnostics.hxx>
@@ -10,7 +10,7 @@
 #include <libbuild2/cc/guess.hxx>
 #include <libbuild2/cc/module.hxx>
 
-#include <build2/c/target.hxx>
+#include <libbuild2/c/target.hxx>
 
 #ifndef BUILD2_DEFAULT_C
 #  ifdef BUILD2_NATIVE_C
@@ -354,5 +354,22 @@ namespace build2
       m->init (rs, loc, hints);
       return true;
     }
+
+    static const module_functions mod_functions[] =
+    {
+      // NOTE: don't forget to also update the documentation in init.hxx if
+      //       changing anything here.
+
+      {"c.guess",  nullptr, guess_init},
+      {"c.config", nullptr, config_init},
+      {"c",        nullptr, init},
+      {nullptr,    nullptr, nullptr}
+    };
+
+    const module_functions*
+    build2_c_load ()
+    {
+      return mod_functions;
+    }
   }
 }
diff --git a/libbuild2/c/init.hxx b/libbuild2/c/init.hxx
new file mode 100644
index 0000000..92d12a3
--- /dev/null
+++ b/libbuild2/c/init.hxx
@@ -0,0 +1,32 @@
+// file      : libbuild2/c/init.hxx -*- C++ -*-
+// copyright : Copyright (c) 2014-2019 Code Synthesis Ltd
+// license   : MIT; see accompanying LICENSE file
+
+#ifndef LIBBUILD2_C_INIT_HXX
+#define LIBBUILD2_C_INIT_HXX
+
+#include <libbuild2/types.hxx>
+#include <libbuild2/utility.hxx>
+
+#include <libbuild2/module.hxx>
+
+#include <libbuild2/c/export.hxx>
+
+namespace build2
+{
+  namespace c
+  {
+    // Module `c` does not require bootstrapping.
+    //
+    // Submodules:
+    //
+    // `c.guess`  -- registers and sets some variables.
+    // `c.config` -- loads c.guess and sets more variables.
+    // `c`        -- loads c.config and registers target types and rules.
+    //
+    extern "C" LIBBUILD2_C_SYMEXPORT const module_functions*
+    build2_c_load ();
+  }
+}
+
+#endif // LIBBUILD2_C_INIT_HXX
diff --git a/build2/c/target.hxx b/libbuild2/c/target.hxx
index 88e2ef4..b35beab 100644
--- a/build2/c/target.hxx
+++ b/libbuild2/c/target.hxx
@@ -1,9 +1,9 @@
-// file      : build2/c/target.hxx -*- C++ -*-
+// file      : libbuild2/c/target.hxx -*- C++ -*-
 // copyright : Copyright (c) 2014-2019 Code Synthesis Ltd
 // license   : MIT; see accompanying LICENSE file
 
-#ifndef BUILD2_C_TARGET_HXX
-#define BUILD2_C_TARGET_HXX
+#ifndef LIBBUILD2_C_TARGET_HXX
+#define LIBBUILD2_C_TARGET_HXX
 
 #include <libbuild2/types.hxx>
 #include <libbuild2/utility.hxx>
@@ -19,4 +19,4 @@ namespace build2
   }
 }
 
-#endif // BUILD2_C_TARGET_HXX
+#endif // LIBBUILD2_C_TARGET_HXX
diff --git a/libbuild2/module.cxx b/libbuild2/module.cxx
index 4e7080a..37bc817 100644
--- a/libbuild2/module.cxx
+++ b/libbuild2/module.cxx
@@ -39,6 +39,7 @@ namespace build2
   static const char* bundled_modules[] = {
     "bash",
     "bin",
+    "c",
     "cc",
     "in",
     "version"
diff --git a/tests/libbuild2/buildfile b/tests/libbuild2/buildfile
index 1a2d594..1d7faf7 100644
--- a/tests/libbuild2/buildfile
+++ b/tests/libbuild2/buildfile
@@ -4,7 +4,7 @@
 
 import libs = build2%lib{build2}
 
-for m: bash bin cc in version
+for m: bash bin c cc in version
   import libs += build2%lib{build2-$m}
 
 exe{driver}: {hxx cxx}{*} $libs testscript
diff --git a/tests/libbuild2/driver.cxx b/tests/libbuild2/driver.cxx
index 679b0a4..e17cdc5 100644
--- a/tests/libbuild2/driver.cxx
+++ b/tests/libbuild2/driver.cxx
@@ -10,6 +10,7 @@
 
 #include <libbuild2/in/init.hxx>
 #include <libbuild2/bin/init.hxx>
+#include <libbuild2/c/init.hxx>
 #include <libbuild2/cc/init.hxx>
 #include <libbuild2/bash/init.hxx>
 #include <libbuild2/version/init.hxx>
@@ -26,6 +27,7 @@ main (int, char* argv[])
 
   bin::build2_bin_load ();
   cc::build2_cc_load ();
+  c::build2_c_load ();
   version::build2_version_load ();
   in::build2_in_load ();
   bash::build2_bash_load ();