build,tools: fix shared library cross-compile

[PickBas]

Fix Windows DLL build

Fixes building Node.js as a shared library on Windows, including cross-compiling (e.g. arm64 on an x64 host).

• tools/gen_node_def: parse the PE export table statically instead of LoadLibrary/GetProcAddress, so a host-arch tool can read a cross-compiled target-arch libnode.dll. Output is byte-identical to the old tool on native x64 builds.
• node.gyp: when cross-compiling, build gen_node_def for the host so it can run during the build, and have generate_node_def depend on that host build. Also link Dbghelp.lib, winmm.lib, and Ws2_32.lib into the shared library, and don't define BUILDING_NODE_EXTENSION for node_mksnapshot (it links node_base statically, so its symbols must not be marked dllimport).

Testing

Comparing the original gen_node_def with changed (x64):

C:\dev\node_projects\node> cl /EHsc gen_node_def_orig.cc /Fe:gen_node_def_orig.exe
Microsoft (R) C/C++ Optimizing Compiler Version 19.51.36244 for x64
Copyright (C) Microsoft Corporation.  All rights reserved.

gen_node_def_orig.cc
Microsoft (R) Incremental Linker Version 14.51.36244.0
Copyright (C) Microsoft Corporation.  All rights reserved.

/out:gen_node_def_orig.exe
gen_node_def_orig.obj

C:\dev\node_projects\node>gen_node_def_orig.exe out\Release\libnode.dll old.def

C:\dev\node_projects\node>fc old.def out\Release\node.def
Comparing files old.def and OUT\RELEASE\NODE.DEF
FC: no differences encountered

Attempt of .def file generation of the original gen_node_def (arm64):

C:\dev\node_projects\node>gen_node_def_orig.exe out\Release\libnode.dll old.def
ERROR: Failed to load out\Release\libnode.dll

Fixes: #52664

[nodejs-github-bot]

Review requested:

• @nodejs/gyp

[nodejs-github-bot]

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----------------------------------- PR info ------------------------------------
Title      build,tools: fix shared library cross-compile (#63963)
   ⚠  Could not retrieve the email or name of the PR author's from user's GitHub profile!
Branch     PickBas:win-dll-fix -> nodejs:main
Labels     build, tools, needs-ci
Commits    1
 - build,tools: fix shared library cross-compile
Committers 1
 - PickBas <sayed.kirill@gmail.com>
PR-URL: https://github.com/nodejs/node/pull/63963
Fixes: https://github.com/nodejs/node/issues/52664
Reviewed-By: Stefan Stojanovic <stefan.stojanovic@janeasystems.com>
------------------------------ Generated metadata ------------------------------
PR-URL: https://github.com/nodejs/node/pull/63963
Fixes: https://github.com/nodejs/node/issues/52664
Reviewed-By: Stefan Stojanovic <stefan.stojanovic@janeasystems.com>
--------------------------------------------------------------------------------
   ℹ  This PR was created on Wed, 17 Jun 2026 12:31:08 GMT
   ✔  Approvals: 1
   ✔  - Stefan Stojanovic (@StefanStojanovic): https://github.com/nodejs/node/pull/63963#pullrequestreview-4644512383
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CI: https://ci.nodejs.org/job/node-test-pull-request/74807/

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/74813/