Break out DllMain from crypto/cryptlib.c and use it in shared libs only

Reviewed-by: Andy Polyakov <appro@openssl.org>

crypto/build.info

@@ -31,3 +31,7 @@ GENERATE[arm64cpuid.S]=arm64cpuid.pl $(PERLASM_SCHEME)
 INCLUDE[arm64cpuid.o]=.
 GENERATE[armv4cpuid.S]=armv4cpuid.pl $(PERLASM_SCHEME)
 INCLUDE[armv4cpuid.o]=.
+
+IF[{- $config{target} =~ /^(?:Cygwin|mingw|VC-)/ -}]
+  SHARED_SOURCE[../libcrypto]=dllmain.c
+ENDIF

crypto/cryptlib.c

@@ -195,55 +195,6 @@ void OPENSSL_cpuid_setup(void)
 }
 #endif
 
-#if (defined(_WIN32) || defined(__CYGWIN__)) && defined(_WINDLL)
-# ifdef __CYGWIN__
-/* pick DLL_[PROCESS|THREAD]_[ATTACH|DETACH] definitions */
-#  include <windows.h>
-/*
- * this has side-effect of _WIN32 getting defined, which otherwise is
- * mutually exclusive with __CYGWIN__...
- */
-# endif
-
-/*
- * All we really need to do is remove the 'error' state when a thread
- * detaches
- */
-
-BOOL WINAPI DllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved);
-BOOL WINAPI DllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved)
-{
-    switch (fdwReason) {
-    case DLL_PROCESS_ATTACH:
-        OPENSSL_cpuid_setup();
-# if defined(_WIN32_WINNT)
-        {
-            IMAGE_DOS_HEADER *dos_header = (IMAGE_DOS_HEADER *) hinstDLL;
-            IMAGE_NT_HEADERS *nt_headers;
-
-            if (dos_header->e_magic == IMAGE_DOS_SIGNATURE) {
-                nt_headers = (IMAGE_NT_HEADERS *) ((char *)dos_header
-                                                   + dos_header->e_lfanew);
-                if (nt_headers->Signature == IMAGE_NT_SIGNATURE &&
-                    hinstDLL !=
-                    (HINSTANCE) (nt_headers->OptionalHeader.ImageBase))
-                    OPENSSL_NONPIC_relocated = 1;
-            }
-        }
-# endif
-        break;
-    case DLL_THREAD_ATTACH:
-        break;
-    case DLL_THREAD_DETACH:
-        OPENSSL_thread_stop();
-        break;
-    case DLL_PROCESS_DETACH:
-        break;
-    }
-    return (TRUE);
-}
-#endif
-
 #if defined(_WIN32) && !defined(__CYGWIN__)
 # include <tchar.h>
 # include <signal.h>

crypto/dllmain.c

@@ -0,0 +1,51 @@
+#include "internal/cryptlib_int.h"
+
+#if defined(_WIN32) || defined(__CYGWIN__)
+# ifdef __CYGWIN__
+/* pick DLL_[PROCESS|THREAD]_[ATTACH|DETACH] definitions */
+#  include <windows.h>
+/*
+ * this has side-effect of _WIN32 getting defined, which otherwise is
+ * mutually exclusive with __CYGWIN__...
+ */
+# endif
+
+/*
+ * All we really need to do is remove the 'error' state when a thread
+ * detaches
+ */
+
+BOOL WINAPI DllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved);
+BOOL WINAPI DllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved)
+{
+    switch (fdwReason) {
+    case DLL_PROCESS_ATTACH:
+        OPENSSL_cpuid_setup();
+# if defined(_WIN32_WINNT)
+        {
+            IMAGE_DOS_HEADER *dos_header = (IMAGE_DOS_HEADER *) hinstDLL;
+            IMAGE_NT_HEADERS *nt_headers;
+
+            if (dos_header->e_magic == IMAGE_DOS_SIGNATURE) {
+                nt_headers = (IMAGE_NT_HEADERS *) ((char *)dos_header
+                                                   + dos_header->e_lfanew);
+                if (nt_headers->Signature == IMAGE_NT_SIGNATURE &&
+                    hinstDLL !=
+                    (HINSTANCE) (nt_headers->OptionalHeader.ImageBase))
+                    OPENSSL_NONPIC_relocated = 1;
+            }
+        }
+# endif
+        break;
+    case DLL_THREAD_ATTACH:
+        break;
+    case DLL_THREAD_DETACH:
+        OPENSSL_thread_stop();
+        break;
+    case DLL_PROCESS_DETACH:
+        break;
+    }
+    return (TRUE);
+}
+#endif
+