electron/patches/common/v8/build_gn.patch

diff --git a/BUILD.gn b/BUILD.gn
index 494ba22f29..6071422d7d 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -157,7 +157,7 @@ config("internal_config") {
 
   include_dirs = [ "." ]
 
-  if (is_component_build) {
+  if (is_component_build || is_electron_build) {
     defines = [ "BUILDING_V8_SHARED" ]
   }
 }
@@ -174,6 +174,20 @@ config("libplatform_config") {
   if (is_component_build) {
     defines = [ "USING_V8_PLATFORM_SHARED" ]
   }
+
+  # For Electron "static_library" all V8 symbols are together in one DLL.
+  # V8 targets which depend on libplatform need to be built with
+  # BUILDING_V8_PLATFORM_SHARED in order to declare its symbols as exported.
+  #
+  # Caveat:
+  # This setting applies to _all_ dependent targets, even those outside
+  # of V8! Currently there are no other targets dependent on v8_libplatform
+  # which Electron would consume, so we don't need to do more complicated tweaks
+  # but be aware of this and check that it's still the case when upgrading
+  # to newer Chromium version.
+  if (is_electron_build && !is_electron_gn_build && !is_component_build) {
+    defines = [ "BUILDING_V8_PLATFORM_SHARED" ]
+  }
 }
 
 # This config should be applied to code using the libbase.
@@ -185,6 +199,20 @@ config("libbase_config") {
   if (is_android && current_toolchain != host_toolchain) {
     libs += [ "log" ]
   }
+
+  # For Electron "static_library" all V8 symbols are together in one DLL.
+  # V8 targets which depend on libbase need to be built with
+  # BUILDING_V8_BASE_SHARED in order to declare its symbols as exported.
+  #
+  # Caveat:
+  # This setting applies to _all_ dependent targets, even those outside
+  # of V8! Currently there are no other targets dependent on v8_libbase
+  # which Electron would consume, so we don't need to do more complicated tweaks
+  # but be aware of this and check that it's still the case when upgrading
+  # to newer Chromium version.
+  if (is_electron_build && !is_electron_gn_build && !is_component_build) {
+    defines = [ "BUILDING_V8_BASE_SHARED" ]
+  }
 }
 
 # This config should be applied to code using the libsampler.
@@ -209,7 +209,7 @@ config("libsampler_config") {
 # itself.
 config("external_config") {
   defines = []
-  if (is_component_build) {
+  if (is_component_build || (is_electron_build && !is_electron_gn_build)) {
     defines += [ "USING_V8_SHARED" ]
   }
   if (v8_enable_v8_checks) {
@@ -2674,6 +2674,8 @@ if (current_toolchain == v8_snapshot_toolchain) {
 
     configs = [ ":internal_config" ]
 
+    configs += [ "//electron/build/config:build_time_executable" ]
+
     deps = [
       ":v8_base",
       ":v8_init",
@@ -2667,7 +2697,7 @@ group("v8_fuzzers") {
   ]
 }
 
-if (is_component_build) {
+if (is_component_build || (is_electron_build && !is_electron_gn_build)) {
   v8_component("v8") {
     sources = [
       "src/v8dll-main.cc",
@@ -2681,6 +2711,13 @@ if (is_component_build) {
     configs = [ ":internal_config" ]
 
     public_configs = [ ":external_config" ]
+
+    # For Electron "static_library" keep V8 as a shared library. This is only
+    # needed so that other targets in Chromium build cleanly. Electron doesn't
+    # need the DLL.
+    if (is_electron_build && !is_electron_gn_build && !is_component_build) {
+      static_component_type = "shared_library"
+    }
   }
 
   v8_component("v8_for_testing") {
diff --git a/gni/v8.gni b/gni/v8.gni
index 9a2bb3dff4..53be2017c7 100644
--- a/gni/v8.gni
+++ b/gni/v8.gni
@@ -164,6 +164,16 @@ template("v8_executable") {
 
 template("v8_component") {
   component(target_name) {
+    # If this is a non-component build, but this target forces itself to be
+    # a shared library, we must reset the default configs that were applied
+    # (see the set_defaults("component") statement in BUILDCONFIG.gn)
+    # and assign those for shared libraries.
+    if (defined(invoker.static_component_type) &&
+        invoker.static_component_type == "shared_library") {
+      configs = []
+      configs = default_shared_library_configs
+    }
+
     forward_variables_from(invoker, "*", [ "configs" ])
     configs += invoker.configs
     configs -= v8_remove_configs
diff --git a/src/inspector/BUILD.gn b/src/inspector/BUILD.gn
index 699b1bcbd4..11fc31d851 100644
--- a/src/inspector/BUILD.gn
+++ b/src/inspector/BUILD.gn
@@ -79,7 +79,7 @@ action("inspector_injected_script") {
 
 config("inspector_config") {
   visibility = [ ":*" ]  # Only targets in this file can depend on this.
-  if (is_component_build) {
+  if (is_component_build || is_electron_build) {
     defines = [ "BUILDING_V8_SHARED" ]
   }
 }