From 8b4c281377822f1289d8db884eb70efa022407f8 Mon Sep 17 00:00:00 2001
From: Siddharth Chandrasekaran <sidcha.dev@gmail.com>
Date: Thu, 21 Mar 2024 12:42:13 +0100
Subject: [PATCH] cmake: Fix MSVC OSDP_EXPORT macro issue

Signed-off-by: Siddharth Chandrasekaran <sidcha.dev@gmail.com>
---
 CMakeLists.txt     |  4 +---
 src/CMakeLists.txt | 44 +++++++++++++++++++++++++++-----------------
 2 files changed, 28 insertions(+), 20 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index c76db21..65f38d8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -26,9 +26,7 @@ include(BuildType)
 include(GNUInstallDirs)
 
 ## Global settings
-if(MSVC)
-	add_compile_options(/W4 /WX)
-else()
+if(NOT MSVC)
 	add_compile_options(-Wall -Wextra)
 endif()
 
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 530bda4..d752c0c 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -161,15 +161,6 @@ install(
 	ARCHIVE DESTINATION ${LIBOSDP_LIBRARY_DIR}
 	PUBLIC_HEADER DESTINATION include/libosdp
 )
-
-# generate osdp_export.h for OSDP_EXPORT() macro
-# must be placed after the target definitions.
-include(GenerateExportHeader)
-generate_export_header(${LIB_OSDP_STATIC}
-	BASE_NAME OSDP
-	EXPORT_FILE_NAME ${CMAKE_CURRENT_BINARY_DIR}/osdp_export.h
-)
-
 endif() # CONFIG_BUILD_STATIC
 
 ################################################
@@ -230,16 +221,35 @@ install(
 	PUBLIC_HEADER DESTINATION include/libosdp
 )
 
-# generate osdp_export.h for OSDP_EXPORT() macro
-# must be placed after the target definitions.
-include(GenerateExportHeader)
-generate_export_header(${LIB_OSDP_SHARED}
-	BASE_NAME OSDP
-	EXPORT_FILE_NAME ${CMAKE_CURRENT_BINARY_DIR}/osdp_export.h
-)
-
 endif() # CONFIG_BUILD_SHARED
 
+if (MSVC)
+	# MSVC expects the function declation to match the definition.
+	# This requires osdp.h also have a lot of OSDP_EXPORT prefixes which
+	# looks ugly. So for now, we will just disable this entirely.
+	string(CONCAT EXPORT_CONTENT
+		"#ifndef OSDP_EXPORT_H\n"
+		"#define OSDP_EXPORT_H\n"
+		"\n"
+		"#define OSDP_EXPORT\n"
+		"#define OSDP_NO_EXPORT\n"
+		"#define OSDP_DEPRECATED_EXPORT\n"
+		"#endif"
+	)
+	file(
+		GENERATE OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/osdp_export.h
+		CONTENT "${EXPORT_CONTENT}"
+	)
+else()
+	# generate osdp_export.h for OSDP_EXPORT macro
+	# must be placed after the target definitions.
+	include(GenerateExportHeader)
+	generate_export_header(${LIB_TARGET}
+		BASE_NAME OSDP
+		EXPORT_FILE_NAME ${CMAKE_CURRENT_BINARY_DIR}/osdp_export.h
+	)
+endif() # MSVC
+
 # pkg-config file
 configure_file(
 	${PROJECT_SOURCE_DIR}/misc/libosdp.pc.in