squashme: fix for cmake builds and openssl forks

- For cmake only build dllmain.c for SHARED builds.

- For DllMain do not call OPENSSL_thread_stop for OpenSSL forks.

lib/CMakeLists.txt

@@ -31,9 +31,12 @@ configure_file(curl_config.h.cmake
 transform_makefile_inc("Makefile.inc" "${CMAKE_CURRENT_BINARY_DIR}/Makefile.inc.cmake")
 include(${CMAKE_CURRENT_BINARY_DIR}/Makefile.inc.cmake)
 
-list(APPEND HHEADERS
- ${CMAKE_CURRENT_BINARY_DIR}/curl_config.h
- )
+# DllMain is added later for DLL builds only.
+list(REMOVE_ITEM CSOURCES dllmain.c)
+set_source_files_properties(dllmain.c PROPERTIES
+ COMPILE_FLAGS -DCURL_CMAKE_DLLMAIN)
+
+list(APPEND HHEADERS ${CMAKE_CURRENT_BINARY_DIR}/curl_config.h)
 
 # The rest of the build
 
@@ -64,9 +67,10 @@ if(ENABLE_CURLDEBUG)
 endif()
 
 if(CYGWIN)
- # for cygwin compile dllmain.c separately since it includes windows.h, which
- # shouldn't be included for other units.
- set_source_files_properties(dllmain.c PROPERTIES SKIP_UNITY_BUILD_INCLUSION ON)
+ # For cygwin always compile dllmain.c as a separate unit since it includes
+ # windows.h, which shouldn't be included in other units.
+ set_source_files_properties(dllmain.c PROPERTIES
+ SKIP_UNITY_BUILD_INCLUSION ON)
 endif()
 
 if(BUILD_TESTING)
@@ -187,6 +191,9 @@ if(BUILD_SHARED_LIBS)
  list(APPEND libcurl_export ${LIB_SHARED})
  add_library(${LIB_SHARED} SHARED ${LIB_SOURCE})
  add_library(${PROJECT_NAME}::${LIB_SHARED} ALIAS ${LIB_SHARED})
+ if(WIN32 OR CYGWIN)
+ set_property(TARGET ${LIB_SHARED} APPEND PROPERTY SOURCES dllmain.c)
+ endif()
  if(WIN32)
  set_property(TARGET ${LIB_SHARED} APPEND PROPERTY SOURCES libcurl.rc)
  if(HIDES_CURL_PRIVATE_SYMBOLS)

lib/dllmain.c

@@ -24,22 +24,37 @@
 
 #include "curl_setup.h"
 
-#if (defined(_WIN32) || defined(__CYGWIN__)) && !defined(CURL_STATICLIB)
-
-/* WARNING: Including Cygwin windows.h may define _WIN32 in old versions or
- may have unexpected behavior in unity builds (where all source files are
- bundled into a single unit). For that reason, this source file must be
- compiled separately for Cygwin unity builds. */
+#ifdef USE_OPENSSL
+#include <openssl/crypto.h>
+#endif
 
+/* The fourth-to-last include */
 #ifdef __CYGWIN__
 #define WIN32_LEAN_AND_MEAN
 #include <windows.h>
+#ifdef _WIN32
+#undef _WIN32
 #endif
-
-#ifdef USE_OPENSSL
-#include <openssl/crypto.h>
 #endif
 
+/* The last 3 #include files should be in this order */
+#include "curl_printf.h"
+#include "curl_memory.h"
+#include "memdebug.h"
+
+/*
+ * DllMain() must only be defined for Windows and Cygwin DLL builds. For most
+ * build systems that means CURL_STATICLIB is not defined. However, CMake
+ * defines CURL_STATICLIB always for Windows builds (discussion in #12408).
+ * CMake builds dllmain.c only for Windows and Cygwin DLL builds and defines
+ * CURL_CMAKE_DLLMAIN.
+ */
+
+#if (defined(_WIN32) || defined(__CYGWIN__)) && \
+ (!defined(CURL_STATICLIB) || defined(CURL_CMAKE_DLLMAIN))
+
+BOOL WINAPI DllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved);
+
 BOOL WINAPI DllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved)
 {
  (void)hinstDLL;
@@ -53,7 +68,12 @@ BOOL WINAPI DllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved)
  case DLL_THREAD_ATTACH:
  break;
  case DLL_THREAD_DETACH:
-#if defined(USE_OPENSSL) && (OPENSSL_VERSION_NUMBER >= 0x10100000L)
+ MessageBoxA(NULL, "test", "", 0);
+#if defined(USE_OPENSSL) && \
+ !defined(OPENSSL_IS_AWSLC) && \
+ !defined(OPENSSL_IS_BORINGSSL) && \
+ !defined(LIBRESSL_VERSION_NUMBER) && \
+ (OPENSSL_VERSION_NUMBER >= 0x10100000L)
  /* Call OPENSSL_thread_stop to prevent a memory leak in case OpenSSL is
  linked statically.
  https://github.com/curl/curl/issues/12327#issuecomment-1826405944 */
@@ -64,4 +84,4 @@ BOOL WINAPI DllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved)
  return TRUE;
 }
 
-#endif /* (_WIN32 || __CYGWIN__) && !CURL_STATICLIB */
+#endif /* DLL build */