build: add a tentative implementation for custom plugin PCH with clang

This is a workaround for mesonbuild/meson#4350
This does not work with all C++ compilers and is "use at own risk",
 therefore disabled by default. Can be enabled by passing
 `-Dcustom_pch=true` to meson.
 When disabled, it should not affect anything.

Speeds up compilation by at least 20% in local tests (48s vs 38s).

meson.build

@@ -204,6 +204,14 @@ configure_file(input: 'config.h.in',
                install_dir: join_paths('include', 'wayfire'),
                configuration: conf_data)
 
+# Detect address sanitizer
+cxx_flags_asan = run_command('/bin/sh', '-c', 'echo $CXXFLAGS $CPPFLAGS | grep fsanitize', check: false)
+if get_option('b_sanitize').contains('address') or cxx_flags_asan.returncode() == 0
+  has_asan = true
+else
+  has_asan = false
+endif
+
 subdir('proto')
 subdir('src')
 subdir('man')

meson_options.txt

@@ -6,3 +6,4 @@ option('xwayland', type: 'feature', value: 'auto', description: 'Build with xway
 option('default_config_backend', type: 'string', value: 'default', description: 'Default configuration backend to use')
 option('print_trace', type: 'boolean', value: true, description: 'Print stack trace in debug logs (disables coredump)')
 option('tests', type: 'feature', value: 'auto', description: 'Enable unit tests')
+option('custom_pch', type: 'boolean', value: false, description: 'Use custom PCH for plugins. May not work with all compilers and setups.')

plugins/animate/meson.build

@@ -1,15 +1,21 @@
 dependencies = [wlroots, pixman, wfconfig]
+animate_pch_deps = [plugin_pch_dep]
+animate_pch_flags = plugin_pch_args
 
 if get_option('enable_openmp')
    dependencies += [dependency('openmp')]
+   # PCH does not have openmp enabled
+   animate_pch_deps = []
+   animate_pch_args = []
 endif
 
 animiate = shared_module('animate',
                          ['animate.cpp',
                           'fire/particle.cpp',
                           'fire/fire.cpp'],
                          include_directories: [wayfire_api_inc, wayfire_conf_inc],
-                         dependencies: dependencies,
+                         dependencies: dependencies + animate_pch_deps,
+                         cpp_args: animate_pch_args,
                          install: true,
                          install_dir: join_paths(get_option('libdir'), 'wayfire'))
 

plugins/blur/meson.build

@@ -1,13 +1,15 @@
 blur_base = shared_library('wayfire-blur-base',
      ['blur-base.cpp', 'box.cpp', 'gaussian.cpp', 'kawase.cpp', 'bokeh.cpp'],
      include_directories: [wayfire_api_inc, wayfire_conf_inc],
-     dependencies: [wlroots, pixman, wfconfig],
+     dependencies: [wlroots, pixman, wfconfig, plugin_pch_dep],
+     cpp_args: plugin_pch_args,
      override_options: ['b_lundef=false'],
      install: true)
 install_headers(['blur.hpp'], subdir: 'wayfire/plugins/blur')
 
 blur = shared_module('blur', ['blur.cpp'],
      link_with: blur_base,
      include_directories: [wayfire_api_inc, wayfire_conf_inc],
-     dependencies: [wlroots, pixman, wfconfig],
+     dependencies: [wlroots, pixman, wfconfig, plugin_pch_dep],
+     cpp_args: plugin_pch_args,
      install: true, install_dir: join_paths(get_option('libdir'), 'wayfire'))

plugins/cube/meson.build

@@ -1,6 +1,7 @@
 animiate = shared_module('cube',
                          ['cube.cpp', 'cubemap.cpp', 'skydome.cpp', 'simple-background.cpp'],
                          include_directories: [wayfire_api_inc, wayfire_conf_inc, plugins_common_inc, ipc_include_dirs],
-                         dependencies: [wlroots, pixman, wfconfig, json],
+                         dependencies: [wlroots, pixman, wfconfig, json, plugin_pch_dep],
+                         cpp_args: plugin_pch_args,
                          install: true,
                          install_dir: join_paths(get_option('libdir'), 'wayfire'))

plugins/decor/meson.build

@@ -2,6 +2,7 @@ decoration = shared_module('decoration',
     ['decoration.cpp', 'deco-subsurface.cpp', 'deco-button.cpp',
       'deco-layout.cpp', 'deco-theme.cpp'],
     include_directories: [wayfire_api_inc, wayfire_conf_inc, plugins_common_inc],
-    dependencies: [wlroots, pixman, wf_protos, wfconfig, cairo, pango, pangocairo],
+    dependencies: [wlroots, pixman, wf_protos, wfconfig, cairo, pango, pangocairo, plugin_pch_dep],
+    cpp_args: plugin_pch_args,
     install: true,
     install_dir: join_paths(get_option('libdir'), 'wayfire'))

plugins/grid/meson.build

@@ -1,10 +1,11 @@
 grid_inc = include_directories('.')
 all_include_dirs = [wayfire_api_inc, wayfire_conf_inc, plugins_common_inc, wobbly_inc, grid_inc]
-all_deps = [wlroots, pixman, wfconfig, wftouch, cairo, json]
+all_deps = [wlroots, pixman, wfconfig, wftouch, cairo, json, plugin_pch_dep]
 
 shared_module('grid', ['grid.cpp'],
         include_directories: all_include_dirs,
         dependencies: all_deps,
+        cpp_args: plugin_pch_args,
         install: true,
         install_dir: conf_data.get('PLUGIN_PATH'))
 

plugins/ipc-rules/ipc-events.hpp

@@ -4,7 +4,6 @@
 #include <set>
 #include "plugins/ipc/ipc-method-repository.hpp"
 #include <wayfire/per-output-plugin.hpp>
-#include <nlohmann/json.hpp>
 
 namespace wf
 {

plugins/ipc-rules/ipc-rules-common.hpp

@@ -2,7 +2,6 @@
 #include "plugins/ipc/ipc-helpers.hpp"
 #include <wayfire/output.hpp>
 #include <wayfire/workarea.hpp>
-#include <nlohmann/json.hpp>
 #include <wayfire/workspace-set.hpp>
 #include "config.h"
 #include "wayfire/plugins/common/util.hpp"

plugins/ipc-rules/meson.build

@@ -1,8 +1,9 @@
 all_include_dirs = [wayfire_api_inc, wayfire_conf_inc, plugins_common_inc]
-all_deps = [wlroots, pixman, wfconfig, wftouch, json]
+all_deps = [wlroots, pixman, wfconfig, wftouch, json, plugin_pch_dep]
 
 shared_module('ipc-rules', ['ipc-rules.cpp'],
         include_directories: all_include_dirs,
+        cpp_args: plugin_pch_args,
         dependencies: all_deps,
         install: true,
         install_dir: conf_data.get('PLUGIN_PATH'))

plugins/ipc/ipc-helpers.hpp

@@ -7,7 +7,7 @@
 #include <wayfire/core.hpp>
 #include <wayfire/output-layout.hpp>
 #include <wayfire/core.hpp>
-#include <nlohmann/json.hpp>
+#include <nlohmann/json.hpp> // IWYU pragma: keep
 
 namespace wf
 {

plugins/ipc/ipc-method-repository.hpp

@@ -1,6 +1,6 @@
 #pragma once
 
-#include <nlohmann/json.hpp>
+#include <nlohmann/json.hpp> // IWYU pragma: keep
 #include <functional>
 #include <map>
 #include "wayfire/signal-provider.hpp"

plugins/ipc/ipc.hpp

@@ -1,6 +1,6 @@
 #pragma once
 
-#include <nlohmann/json.hpp>
+#include <nlohmann/json.hpp> // IWYU pragma: keep
 #include <sys/un.h>
 #include <wayfire/object.hpp>
 #include <wayland-server.h>

plugins/ipc/meson.build

@@ -5,21 +5,24 @@ ipc_include_dirs = include_directories('.')
 ipc = shared_module('ipc',
     ['ipc.cpp'],
     include_directories: [wayfire_api_inc, wayfire_conf_inc, plugins_common_inc],
-    dependencies: [wlroots, pixman, wfconfig, wftouch, json, evdev],
+    dependencies: [wlroots, pixman, wfconfig, wftouch, json, evdev, plugin_pch_dep],
+    cpp_args: plugin_pch_args,
     install: true,
     install_dir: conf_data.get('PLUGIN_PATH'))
 
 stipc = shared_module('stipc',
     ['stipc.cpp'],
     include_directories: [wayfire_api_inc, wayfire_conf_inc, plugins_common_inc],
-    dependencies: [wlroots, pixman, wfconfig, wftouch, json, evdev],
+    dependencies: [wlroots, pixman, wfconfig, wftouch, json, evdev, plugin_pch_dep],
+    cpp_args: plugin_pch_args,
     install: true,
     install_dir: conf_data.get('PLUGIN_PATH'))
 
 demoipc = shared_module('demo-ipc',
     ['demo-ipc.cpp'],
     include_directories: [wayfire_api_inc, wayfire_conf_inc, plugins_common_inc],
-    dependencies: [wlroots, pixman, wfconfig, wftouch, json, evdev],
+    dependencies: [wlroots, pixman, wfconfig, wftouch, json, evdev, plugin_pch_dep],
+    cpp_args: plugin_pch_args,
     install: true,
     install_dir: conf_data.get('PLUGIN_PATH'))
 

plugins/meson.build

@@ -1,4 +1,37 @@
 subdir('common')
+
+if get_option('custom_pch')
+  cc = meson.get_compiler('cpp')
+
+  pch_file = meson.current_source_dir() / 'pch/pch.hpp'
+  if cc.get_id() == 'clang'
+    add_flags = []
+    if get_option('buildtype') == 'debugoptimized' or get_option('buildtype') == 'release'
+      add_flags += ['-O2']
+    endif
+
+    if has_asan
+      add_flags += ['-fsanitize=address']
+    endif
+
+    pch = custom_target('plugin_pch',
+        input: pch_file,
+        output: 'plugin_pch.hpp.pch',
+        command: cc.cmd_array() + ['@INPUT@', '-c', '-o', '@OUTPUT@',
+          '-std=c++17', '-pthread', '-fPIC'] + add_flags)
+
+    plugin_pch_args = ['-include-pch', pch.full_path(), '-pthread']
+    plugin_pch_dep = declare_dependency(sources: pch)
+  elif cc.get_id() == 'gcc'
+    error('TODO: CUSTOM PCH FOR GCC')
+  else
+    error('Unsupported compiler for custom pch: ' + cc.get_id())
+  endif
+else
+  plugin_pch_args = []
+  plugin_pch_dep = declare_dependency()
+endif
+
 subdir('ipc')
 subdir('protocols')
 subdir('vswitch')

plugins/pch/pch.hpp

@@ -0,0 +1,13 @@
+#include <wayland-server.h>
+#include <glm/glm.hpp>
+
+#include <string>
+#include <vector>
+#include <utility>
+#include <memory>
+#include <functional>
+#include <algorithm>
+#include <sstream>
+#include <map>
+#include <cmath>
+#include <cstddef>

plugins/protocols/meson.build

@@ -4,12 +4,13 @@ protocol_plugins = [
 ]
 
 all_include_dirs = [wayfire_api_inc, wayfire_conf_inc, plugins_common_inc]
-all_deps = [wlroots, pixman, wfconfig, wf_protos, json, cairo, pango, pangocairo]
+all_deps = [wlroots, pixman, wfconfig, wf_protos, json, cairo, pango, pangocairo, plugin_pch_dep]
 
 foreach plugin : protocol_plugins
   shared_module(plugin, plugin + '.cpp',
       include_directories: all_include_dirs,
       dependencies: all_deps,
+      cpp_args: plugin_pch_args,
       install: true,
       install_dir: conf_data.get('PLUGIN_PATH'))
 endforeach

plugins/scale/meson.build

@@ -1,15 +1,17 @@
 all_include_dirs = [wayfire_api_inc, wayfire_conf_inc, plugins_common_inc, vswitch_inc, wobbly_inc, include_directories('.')]
-all_deps = [wlroots, pixman, wfconfig, wftouch, cairo, pango, pangocairo, json]
+all_deps = [wlroots, pixman, wfconfig, wftouch, cairo, pango, pangocairo, json, plugin_pch_dep]
 
 shared_module('scale', ['scale.cpp', 'scale-title-overlay.cpp'],
         include_directories: all_include_dirs,
         dependencies: all_deps,
+        cpp_args: plugin_pch_args,
         install: true,
         install_dir: conf_data.get('PLUGIN_PATH'))
 
 shared_module('scale-title-filter', 'scale-title-filter.cpp',
         include_directories: all_include_dirs,
         dependencies: all_deps,
+        cpp_args: plugin_pch_args,
         install: true,
         install_dir: conf_data.get('PLUGIN_PATH'))
 

plugins/single_plugins/meson.build

@@ -6,12 +6,13 @@ plugins = [
 ]
 
 all_include_dirs = [wayfire_api_inc, wayfire_conf_inc, plugins_common_inc, vswitch_inc, wobbly_inc, grid_inc]
-all_deps = [wlroots, pixman, wfconfig, wftouch, cairo, pango, pangocairo, json]
+all_deps = [wlroots, pixman, wfconfig, wftouch, cairo, pango, pangocairo, json, plugin_pch_dep]
 
 foreach plugin : plugins
   shared_module(plugin, plugin + '.cpp',
       include_directories: all_include_dirs,
       dependencies: all_deps,
+      cpp_args: plugin_pch_args,
       install: true,
       install_dir: conf_data.get('PLUGIN_PATH'))
 endforeach

plugins/tile/meson.build

@@ -1,7 +1,8 @@
 tile = shared_module('simple-tile',
         ['tile-plugin.cpp', 'tree.cpp', 'tree-controller.cpp'],
         include_directories: [wayfire_api_inc, wayfire_conf_inc, plugins_common_inc, grid_inc, wobbly_inc, ipc_include_dirs],
-        dependencies: [wlroots, pixman, wfconfig, json],
+        dependencies: [wlroots, pixman, wfconfig, json, plugin_pch_dep],
+        cpp_args: plugin_pch_args,
         install: true,
         install_dir: join_paths(get_option('libdir'), 'wayfire'))
 

plugins/tile/tile-ipc.hpp

@@ -4,7 +4,6 @@
 #include <wayfire/workspace-set.hpp>
 #include <wayfire/toplevel-view.hpp>
 #include "tree.hpp"
-#include <nlohmann/json.hpp>
 #include "plugins/ipc/ipc-helpers.hpp"
 #include "plugins/ipc/ipc-method-repository.hpp"
 #include "tile-wset.hpp"

plugins/vswitch/meson.build

@@ -3,7 +3,8 @@ vswitch_inc = include_directories('.')
 vswitch = shared_module('vswitch',
     ['vswitch.cpp'],
     include_directories: [wayfire_api_inc, wayfire_conf_inc, plugins_common_inc, vswitch_inc, ipc_include_dirs],
-    dependencies: [wlroots, pixman, wfconfig, json],
+    dependencies: [wlroots, pixman, wfconfig, json, plugin_pch_dep],
+    cpp_args: plugin_pch_args,
     install: true,
     install_dir: join_paths(get_option('libdir'), 'wayfire'))
 

plugins/window-rules/meson.build

@@ -1,7 +1,7 @@
 window_rules  = shared_module('window-rules',
                               ['window-rules.cpp', 'view-action-interface.cpp'],
                               include_directories: [wayfire_api_inc, wayfire_conf_inc, grid_inc, plugins_common_inc],
-                              dependencies: [wlroots, pixman, wfconfig, wfutils],
+                              dependencies: [wlroots, pixman, wfconfig, wfutils, plugin_pch_dep],
+                              cpp_args: plugin_pch_args,
                               install: true,
-                              install_dir: join_paths(get_option('libdir'), 'wayfire')
-                              )
+                              install_dir: join_paths(get_option('libdir'), 'wayfire'))

plugins/wm-actions/meson.build

@@ -1,7 +1,8 @@
 wm_actions = shared_module('wm-actions',
                            ['wm-actions.cpp'],
                            include_directories: [wayfire_api_inc, wayfire_conf_inc, plugins_common_inc],
-                           dependencies: [wlroots, pixman, wfconfig, json],
+                           dependencies: [wlroots, pixman, wfconfig, json, plugin_pch_dep],
+                           cpp_args: plugin_pch_args,
                            install: true,
                            install_dir: join_paths(get_option('libdir'), 'wayfire'))
 

plugins/wobbly/meson.build

@@ -1,7 +1,11 @@
+wobbly_c_model = static_library('wobbly-c-model', ['wobbly.c'], install: false)
+
 wobbly = shared_module('wobbly',
-                       ['wobbly.cpp', 'wobbly.c'],
+                       ['wobbly.cpp'],
                        include_directories: [wayfire_api_inc, wayfire_conf_inc, plugins_common_inc],
-                       dependencies: [wlroots, pixman, wfconfig],
+                       dependencies: [wlroots, pixman, wfconfig, plugin_pch_dep],
+                       cpp_args: plugin_pch_args,
+                       link_with: wobbly_c_model,
                        install: true,
                        install_dir: join_paths(get_option('libdir'), 'wayfire'))
 

plugins/wobbly/wayfire/plugins/wobbly/wobbly-signal.hpp

@@ -1,4 +1,5 @@
 #pragma once
+
 #include <wayfire/signal-definitions.hpp>
 #include <wayfire/core.hpp>
 #include <wayfire/toplevel-view.hpp>

src/api/wayfire/nonstd/wlroots.hpp

@@ -1,7 +1,7 @@
 #pragma once
 
 #ifndef WLR_USE_UNSTABLE
-    #define WLR_USE_UNSTABLE
+    #define WLR_USE_UNSTABLE 1
 #endif
 
 /**

src/api/wayfire/per-output-plugin.hpp

@@ -1,3 +1,5 @@
+#pragma once
+
 #include "wayfire/signal-provider.hpp"
 #include <wayfire/plugin.hpp>
 #include <wayfire/core.hpp>

src/meson.build

@@ -81,8 +81,7 @@ else
 endif
 
 
-cxx_flags_asan = run_command('/bin/sh', '-c', 'echo $CXXFLAGS $CPPFLAGS | grep fsanitize', check: false)
-if get_option('b_sanitize').contains('address') or cxx_flags_asan.returncode() == 0
+if has_asan
   print_trace = false
   debug_arguments += ['-DHAS_ASAN=1']
   message('Address sanitizer enabled, disabling internal backtrace')