From 2471001648cbc12462f0754a5e1c4b0db414c7b7 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Tue, 19 May 2026 21:25:44 +0000
Subject: [PATCH 1/2] Initial plan


From 8a8b080edbbdf75fc081538624aa45b279c430aa Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Tue, 19 May 2026 21:28:42 +0000
Subject: [PATCH 2/2] Fix LNK4006 duplicate symbol warning in Windows static
 CMake builds

Replace `#ifndef hidapi_winapi_EXPORTS` guard in windows/hid.c with
`#ifndef HIDAPI_CMAKE_V0_BUILD`, and define HIDAPI_CMAKE_V0_BUILD as a
PRIVATE compile definition on the hidapi_winapi CMake target.

When building with CMake, hidapi_descriptor_reconstruct.c is compiled as
a separate translation unit. The old guard relied on hidapi_winapi_EXPORTS
which is only set for shared (DLL) builds, causing the file to be compiled
twice in static builds and producing a benign-but-noisy LNK4006 warning.

The new HIDAPI_CMAKE_V0_BUILD define is set for all CMake builds (both
shared and static), so hid.c never #includes the .c file when using CMake.
Legacy build systems that don't define HIDAPI_CMAKE_V0_BUILD continue to
work as before because hid.c still #includes the file in that case.

Agent-Logs-Url: https://github.com/libusb/hidapi/sessions/a624aff3-07ad-401b-8587-87bc5203841b

Co-authored-by: Youw <5939659+Youw@users.noreply.github.com>
---
 windows/CMakeLists.txt | 6 ++++++
 windows/hid.c          | 4 +++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/windows/CMakeLists.txt b/windows/CMakeLists.txt
index c8228bc84..d230c703b 100644
--- a/windows/CMakeLists.txt
+++ b/windows/CMakeLists.txt
@@ -22,6 +22,12 @@ target_link_libraries(hidapi_winapi
     PUBLIC hidapi_include
 )
 
+target_compile_definitions(hidapi_winapi
+    # CMake compiles hidapi_descriptor_reconstruct.c as a separate translation unit,
+    # so hid.c must not #include it (to avoid duplicate symbol LNK4006 in static builds).
+    PRIVATE HIDAPI_CMAKE_V0_BUILD
+)
+
 if(NOT BUILD_SHARED_LIBS)
     target_compile_definitions(hidapi_winapi
         # prevent marking functions as __declspec(dllexport) for static library build
diff --git a/windows/hid.c b/windows/hid.c
index 1e27f10a4..705847e0b 100644
--- a/windows/hid.c
+++ b/windows/hid.c
@@ -1607,7 +1607,9 @@ HID_API_EXPORT const wchar_t * HID_API_CALL  hid_error(hid_device *dev)
 	return last_global_error_str;
 }
 
-#ifndef hidapi_winapi_EXPORTS
+#ifndef HIDAPI_CMAKE_V0_BUILD
+/* Include the descriptor reconstruction code when NOT building with CMake.
+   CMake builds compile hidapi_descriptor_reconstruct.c as a separate translation unit. */
 #include "hidapi_descriptor_reconstruct.c"
 #endif