Add another flag for enabling a bit bridge build

cross-wine.conf

@@ -0,0 +1,16 @@
+[binaries]
+c = 'winegcc'
+cpp = 'wineg++'
+ar = 'ar'
+strip = 'strip'
+
+[properties]
+# These would be the arguments for 64-bit compilation. We'll set the `-m64` flag
+# (or `-m32`) in our meson.build to allow the 32-bit bitbridge to be built in
+# the same build directory as the plugin and the regular 64-bit version of the
+# host application to ensure that they are always in sync.
+# c_args = ['-m64']
+# cpp_args = ['-m64']
+# cpp_link_args = ['-m64', '-mwindows']
+cpp_link_args = ['-mwindows']
+needs_exe_wrapper = true

cross-wine64.conf

@@ -1,17 +0,0 @@
-[binaries]
-c = 'winegcc'
-cpp = 'wineg++'
-ar = 'ar'
-strip = 'strip'
-
-[properties]
-c_args=['-m64']
-cpp_args=['-m64']
-cpp_link_args=['-m64', '-mwindows']
-needs_exe_wrapper = true
-
-[host_machine]
-system = 'linux'
-cpu_family = 'x86_64'
-cpu = 'x86_64'
-endian = 'little'

meson.build

@@ -12,9 +12,19 @@ winelib_check = '''#ifndef __WINE__
 #error 1
 #endif'''
 if not meson.get_compiler('cpp').compiles(winelib_check)
-  error('You need to set up a cross compiler, check the README for more information.')
+  error('You need to set up a cross compiler, check the README for compilation instructions.')
 endif
 
+# Depending on the `use-bitbridge` flag we'll enable building a second 32-bit
+# host application that can act as a bit bridge for using 32-bit Windows plugins
+# in 64-bit Linux VST hsots. The plugin will determine which host application to
+# use based on the `.dll` file it's trying to load.
+# This setup is necessary until Meson provides a way to have multiple
+# cross-builds for a single build directory:
+# https://github.com/mesonbuild/meson/issues/5125
+host_name_64bit = 'yabridge-host'
+host_name_32bit = 'yabridge-host-32'
+
 # This provides an easy way to start the Wine VST host using winedbg since it
 # can be quite a pain to set up
 compiler_options = []
@@ -22,13 +32,8 @@ if get_option('use-winedbg')
   compiler_options += '-DUSE_WINEDBG'
 endif
 
-# The application consists of a VST plugin (yabridge) that calls a winelib
-# program (yabridge-host) that can host Windows VST plugins. More information
-# about the way these two components work together can be found in the readme
-# file.
-
 # Generate header files for configuration variables such as the current git tag
-# and the last commit hash
+# and the name of the host binary
 subdir('src/common/config')
 
 boost_dep = dependency('boost', modules : ['filesystem'])
@@ -40,6 +45,11 @@ xcb_dep = dependency('xcb')
 
 include_dir = include_directories('src/include')
 
+# The application consists of a VST plugin (yabridge) that calls a winelib
+# program (yabridge-host) that can host Windows VST plugins. More information
+# about the way these two components work together can be found in the readme
+# file.
+
 shared_library(
   'yabridge',
   [
@@ -56,21 +66,38 @@ shared_library(
   link_args : ['-ldl']
 )
 
+host_sources = [
+  'src/common/logging.cpp',
+  'src/common/serialization.cpp',
+  'src/wine-host/editor.cpp',
+  'src/wine-host/editor.cpp',
+  'src/wine-host/plugin-bridge.cpp',
+  'src/wine-host/vst-host.cpp',
+  'src/wine-host/utils.cpp',
+  version_header,
+]
+
 executable(
-  'yabridge-host',
-  [
-    'src/common/logging.cpp',
-    'src/common/serialization.cpp',
-    'src/wine-host/editor.cpp',
-    'src/wine-host/editor.cpp',
-    'src/wine-host/plugin-bridge.cpp',
-    'src/wine-host/vst-host.cpp',
-    'src/wine-host/utils.cpp',
-    version_header,
-  ],
+  host_name_64bit,
+  host_sources,
   native : false,
   include_directories : include_dir,
   dependencies : [boost_dep, bitsery_dep, wine_threads_dep, xcb_dep],
-  cpp_args : compiler_options,
-  link_args : []
+  cpp_args : compiler_options + ['-m64'],
+  link_args : ['-m64']
 )
+
+if get_option('use-bitbridge')
+  compiler_options += '-DUSE_BITBRIDGE'
+
+  # TODO: Use 32 bit libraries
+  executable(
+    host_name_32bit,
+    host_sources,
+    native : false,
+    include_directories : include_dir,
+    dependencies : [boost_dep, bitsery_dep, wine_threads_dep, xcb_dep],
+    cpp_args : compiler_options + ['-m32'],
+    link_args : ['-m32']
+  )
+endif

meson_options.txt

@@ -1,6 +1,14 @@
+option(
+  'use-bitbridge',
+  type : 'boolean',
+  value : false,
+  description : '''Build a 32-bit host application for hosting 32-bit plugins.
+                   See the readme for full instructions on how to use this.'''
+)
+
 option(
   'use-winedbg',
   type : 'boolean',
   value : false,
-  description: 'Whether to run the Wien VST host with GDB attached. Might not always be reliable.'
+  description : 'Whether to run the Wien VST host with GDB attached. Might not always be reliable.'
 )

src/common/config/config.h.in

@@ -0,0 +1,30 @@
+// yabridge: a Wine VST bridge
+// Copyright (C) 2020  Robbert van der Helm
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+#pragma once
+
+/**
+ * The name of the wine host name, e.g. `yabridge-host.exe` for the regular 64
+ * bit build.
+ */
+constexpr char yabridge_wine_host_name[] = "@host_binary_64bit@";
+
+/**
+ * The name of the 32-bit wine host name, e.g. `yabridge-host-32.exe`.` This is
+ * used as a bitbridge to be able to load legacy 32-bit only Windows plugins
+ * from a 64-bit Linux host.
+ */
+constexpr char yabridge_wine_host_name_32bit[] = "@host_binary_32bit@";

src/common/config/meson.build

@@ -1,3 +1,16 @@
+# Contains constants determined while configuring the build. As an alternative
+# to preprocessor macros.
+config_header = configure_file(
+  input : 'config.h.in',
+  output : 'config.h',
+  configuration : configuration_data(
+    {
+      'host_binary_32bit': host_name_32bit + '.exe',
+      'host_binary_64bit': host_name_64bit + '.exe',
+    }
+  )
+)
+
 # Generate a file containing the last annotated git tag and possibly also the
 # amount of commits since then and the hash of the last commit
 version_header = vcs_tag(

src/plugin/host-bridge.cpp

@@ -30,6 +30,7 @@
 #endif
 
 // Generated inside of build directory
+#include <src/common/config/config.h>
 #include <src/common/config/version.h>
 
 #include "../common/communication.h"
@@ -40,11 +41,6 @@ namespace bp = boost::process;
 // boost::filesystem
 namespace fs = boost::filesystem;
 
-/**
- * The name of the wine VST host binary.
- */
-constexpr auto yabridge_wine_host_name = "yabridge-host.exe";
-
 /**
  * Used for generating random identifiers.
  */
@@ -500,6 +496,8 @@ fs::path find_wine_vst_host() {
         return host_path;
     }
 
+    // TODO: First, check whether the plugin is 32-bit or 64-bit, and then
+    //       search for the correct binary accordingly
     // Bosot will return an empty path if the file could not be found in the
     // search path
     const fs::path vst_host_path = bp::search_path(yabridge_wine_host_name);