Add DLL export/import support

5 files changed, 75 insertions, 17 deletions

diff --git a/bpkg/buildfile b/bpkg/buildfile
index b99d465..955e39d 100644
--- a/bpkg/buildfile
+++ b/bpkg/buildfile
@@ -12,8 +12,15 @@ lib{bpkg}:                               \
 $libs
 
 cxx.poptions =+ -I$src_root
+
 lib{bpkg}: cxx.export.poptions = -I$src_root
 
+liba{bpkg}: cxx.export.poptions += -DLIBBPKG_STATIC
+libs{bpkg}: cxx.export.poptions += -DLIBBPKG_SHARED
+
+obja{*}: cxx.poptions += -DLIBBPKG_STATIC_BUILD
+objs{*}: cxx.poptions += -DLIBBPKG_SHARED_BUILD
+
 # Install into the bpkg/ subdirectory of, say, /usr/include/.
 #
 install.include = $install.include/bpkg
diff --git a/bpkg/export b/bpkg/export
new file mode 100644
index 0000000..7bbb994
--- /dev/null
+++ b/bpkg/export
@@ -0,0 +1,41 @@
+// file      : bpkg/export -*- C++ -*-
+// copyright : Copyright (c) 2014-2016 Code Synthesis Ltd
+// license   : MIT; see accompanying LICENSE file
+
+#ifndef BPKG_EXPORT
+#define BPKG_EXPORT
+
+// 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/import 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 function being
+// used before their inline definition. The workaround is to reorder code. In
+// the end it's all trial and error.
+
+#if defined(LIBBPKG_STATIC)         // Using static.
+#  define LIBBPKG_EXPORT
+#elif defined(LIBBPKG_STATIC_BUILD) // Building static.
+#  define LIBBPKG_EXPORT
+#elif defined(LIBBPKG_SHARED)       // Using shared.
+#  ifdef _WIN32
+#    define LIBBPKG_EXPORT __declspec(dllimport)
+#  else
+#    define LIBBPKG_EXPORT
+#  endif
+#elif defined(LIBBPKG_SHARED_BUILD) // Building shared.
+#  ifdef _WIN32
+#    define LIBBPKG_EXPORT __declspec(dllexport)
+#  else
+#    define LIBBPKG_EXPORT
+#  endif
+#else
+// If none of the above macros are defined, then we assume we are being using
+// 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 LIBBPKG_EXPORT            // Using static or shared.
+#endif
+
+#endif // BPKG_EXPORT
diff --git a/bpkg/manifest b/bpkg/manifest
index 0c9362f..8e9c043 100644
--- a/bpkg/manifest
+++ b/bpkg/manifest
@@ -16,6 +16,8 @@
 #include <butl/path>
 #include <butl/optional>
 
+#include <bpkg/export>
+
 namespace bpkg
 {
   class manifest_parser;
@@ -24,7 +26,7 @@ namespace bpkg
 
   using strings = std::vector<std::string>;
 
-  class version
+  class LIBBPKG_EXPORT version
   {
   public:
     // Let's keep the members in the order they appear in the string
@@ -122,7 +124,7 @@ namespace bpkg
     }
 
   private:
-    struct data_type
+    struct LIBBPKG_EXPORT data_type
     {
       enum class parse {full, upstream, release};
 
@@ -173,7 +175,7 @@ namespace bpkg
   // change
   // change-file
   //
-  class text_file
+  class LIBBPKG_EXPORT text_file
   {
   public:
     using path_type = butl::path;
@@ -245,7 +247,7 @@ namespace bpkg
 
   // depends
   //
-  struct dependency_constraint
+  struct LIBBPKG_EXPORT dependency_constraint
   {
     butl::optional<version> min_version;
     butl::optional<version> max_version;
@@ -264,7 +266,7 @@ namespace bpkg
     empty () const noexcept {return !min_version && !max_version;}
   };
 
-  std::ostream&
+  LIBBPKG_EXPORT std::ostream&
   operator<< (std::ostream&, const dependency_constraint&);
 
   inline bool
@@ -286,7 +288,7 @@ namespace bpkg
     butl::optional<dependency_constraint> constraint;
   };
 
-  std::ostream&
+  LIBBPKG_EXPORT std::ostream&
   operator<< (std::ostream&, const dependency&);
 
   class dependency_alternatives: public std::vector<dependency>
@@ -300,7 +302,7 @@ namespace bpkg
         : conditional (d), comment (std::move (c)) {}
   };
 
-  std::ostream&
+  LIBBPKG_EXPORT std::ostream&
   operator<< (std::ostream&, const dependency_alternatives&);
 
   // requires
@@ -316,7 +318,7 @@ namespace bpkg
         : conditional (d), comment (std::move (c)) {}
   };
 
-  class package_manifest
+  class LIBBPKG_EXPORT package_manifest
   {
   public:
     using version_type = bpkg::version;
@@ -345,6 +347,8 @@ namespace bpkg
     butl::optional<std::string> sha256sum;
 
   public:
+    package_manifest () = default; // VC export.
+
     // Create individual package manifest.
     //
     package_manifest (manifest_parser&, bool ignore_unknown = false);
@@ -365,7 +369,7 @@ namespace bpkg
                       bool ignore_unknown);
   };
 
-  class package_manifests: public std::vector<package_manifest>
+  class LIBBPKG_EXPORT package_manifests: public std::vector<package_manifest>
   {
   public:
     using base_type = std::vector<package_manifest>;
@@ -384,7 +388,7 @@ namespace bpkg
     serialize (manifest_serializer&) const;
   };
 
-  class repository_location
+  class LIBBPKG_EXPORT repository_location
   {
   public:
     // Create a special empty repository_location.
@@ -527,7 +531,7 @@ namespace bpkg
     complement
   };
 
-  class repository_manifest
+  class LIBBPKG_EXPORT repository_manifest
   {
   public:
     using email_type = bpkg::email;
@@ -566,6 +570,7 @@ namespace bpkg
     effective_url (const repository_location&) const;
 
   public:
+    repository_manifest () = default; // VC export.
     repository_manifest (manifest_parser&, bool ignore_unknown = false);
     repository_manifest (manifest_parser&,
                          manifest_name_value start,
@@ -575,7 +580,8 @@ namespace bpkg
     serialize (manifest_serializer&) const;
   };
 
-  class repository_manifests: public std::vector<repository_manifest>
+  class LIBBPKG_EXPORT repository_manifests:
+    public std::vector<repository_manifest>
   {
   public:
     using base_type = std::vector<repository_manifest>;
@@ -589,7 +595,7 @@ namespace bpkg
     serialize (manifest_serializer&) const;
   };
 
-  class signature_manifest
+  class LIBBPKG_EXPORT signature_manifest
   {
   public:
     // Checksum of the corresponding package_manifests.
diff --git a/bpkg/manifest-parser b/bpkg/manifest-parser
index 77918ee..8cbb768 100644
--- a/bpkg/manifest-parser
+++ b/bpkg/manifest-parser
@@ -12,9 +12,11 @@
 
 #include <butl/char-scanner>
 
+#include <bpkg/export>
+
 namespace bpkg
 {
-  class manifest_parsing: public std::runtime_error
+  class LIBBPKG_EXPORT manifest_parsing: public std::runtime_error
   {
   public:
     manifest_parsing (const std::string& name,
@@ -44,7 +46,7 @@ namespace bpkg
     empty () const {return name.empty () && value.empty ();}
   };
 
-  class manifest_parser: protected butl::char_scanner
+  class LIBBPKG_EXPORT manifest_parser: protected butl::char_scanner
   {
   public:
     manifest_parser (std::istream& is, const std::string& name)
diff --git a/bpkg/manifest-serializer b/bpkg/manifest-serializer
index 3116279..501fd30 100644
--- a/bpkg/manifest-serializer
+++ b/bpkg/manifest-serializer
@@ -10,9 +10,11 @@
 #include <cstddef>   // size_t
 #include <stdexcept> // runtime_error
 
+#include <bpkg/export>
+
 namespace bpkg
 {
-  class manifest_serialization: public std::runtime_error
+  class LIBBPKG_EXPORT manifest_serialization: public std::runtime_error
   {
   public:
     manifest_serialization (const std::string& name,
@@ -22,7 +24,7 @@ namespace bpkg
     std::string description;
   };
 
-  class manifest_serializer
+  class LIBBPKG_EXPORT manifest_serializer
   {
   public:
     manifest_serializer (std::ostream& os, const std::string& name)