src: fix --disable-single-executable-application

Previously it would not compile if the build is configured with
--disable-single-executable-application because we use directives
to exclude the definition of SEA-related code completely. This patch
changes them so that the SEA code are still compiled and internals
still check whether the executable is an SEA. If future modifications
to the C++ code attempt to load the SEA blob when SEA is disabled,
UNREACHABLE() would be raised. If user attempt to generate the
SEA blob with --experimental-sea-config with an executable that
disables SEA, they would get an error.

src/node.cc

@@ -1403,13 +1403,16 @@ static ExitCode StartInternal(int argc, char** argv) {
   });
 
   uv_loop_configure(uv_default_loop(), UV_METRICS_IDLE_TIME);
-
   std::string sea_config = per_process::cli_options->experimental_sea_config;
   if (!sea_config.empty()) {
+#if !defined(DISABLE_SINGLE_EXECUTABLE_APPLICATION)
     return sea::BuildSingleExecutableBlob(
         sea_config, result->args(), result->exec_args());
+#else
+    fprintf(stderr, "Single executable application is disabled.\n");
+    return ExitCode::kGenericUserError;
+#endif  // !defined(DISABLE_SINGLE_EXECUTABLE_APPLICATION)
   }
-
   // --build-snapshot indicates that we are in snapshot building mode.
   if (per_process::cli_options->per_isolate->build_snapshot) {
     if (per_process::cli_options->per_isolate->build_snapshot_config.empty() &&

src/node_sea.cc

@@ -27,8 +27,6 @@
 #include <tuple>
 #include <vector>
 
-#if !defined(DISABLE_SINGLE_EXECUTABLE_APPLICATION)
-
 using node::ExitCode;
 using v8::ArrayBuffer;
 using v8::BackingStore;
@@ -189,6 +187,7 @@ SeaResource SeaDeserializer::Read() {
 }
 
 std::string_view FindSingleExecutableBlob() {
+#if !defined(DISABLE_SINGLE_EXECUTABLE_APPLICATION)
   CHECK(IsSingleExecutable());
   static const std::string_view result = []() -> std::string_view {
     size_t size;
@@ -209,6 +208,9 @@ std::string_view FindSingleExecutableBlob() {
                      result.data(),
                      result.size());
   return result;
+#else
+  UNREACHABLE();
+#endif  // !defined(DISABLE_SINGLE_EXECUTABLE_APPLICATION)
 }
 
 }  // anonymous namespace
@@ -668,5 +670,3 @@ void RegisterExternalReferences(ExternalReferenceRegistry* registry) {
 
 NODE_BINDING_CONTEXT_AWARE_INTERNAL(sea, node::sea::Initialize)
 NODE_BINDING_EXTERNAL_REFERENCE(sea, node::sea::RegisterExternalReferences)
-
-#endif  // !defined(DISABLE_SINGLE_EXECUTABLE_APPLICATION)

src/node_sea.h

@@ -3,8 +3,6 @@
 
 #if defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS
 
-#if !defined(DISABLE_SINGLE_EXECUTABLE_APPLICATION)
-
 #include <cinttypes>
 #include <optional>
 #include <string>
@@ -52,8 +50,6 @@ node::ExitCode BuildSingleExecutableBlob(
 }  // namespace sea
 }  // namespace node
 
-#endif  // !defined(DISABLE_SINGLE_EXECUTABLE_APPLICATION)
-
 #endif  // defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS
 
 #endif  // SRC_NODE_SEA_H_