kc3-lang/dlfcn-win32

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 48945b2..a13cf99 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -63,6 +63,8 @@ if (BUILD_TESTS)
   enable_testing()
   add_library(testdll SHARED testdll.c)
   set_target_properties(testdll PROPERTIES PREFIX "")
+  add_library(testdll3 SHARED testdll3.c)
+  set_target_properties(testdll3 PROPERTIES PREFIX "")
   add_executable(t_dlfcn test.c)
   target_link_libraries(t_dlfcn dl)
   add_test (NAME t_dlfcn COMMAND t_dlfcn)
diff --git a/Makefile b/Makefile
index c02dce0..a0f5cb9 100644
--- a/Makefile
+++ b/Makefile
@@ -66,7 +66,10 @@ test.exe: test.o $(TARGETS)
 testdll.dll: testdll.c
 	$(CC) -shared -o $@ $^
 
-test: $(TARGETS) test.exe testdll.dll
+testdll3.dll: testdll3.c
+	$(CC) -shared -o $@ $^
+
+test: $(TARGETS) test.exe testdll.dll testdll3.dll
 	$(WINE) test.exe
 
 clean::
@@ -74,7 +77,7 @@ clean::
 		dlfcn.o \
 		libdl.dll libdl.a libdl.def libdl.dll.a libdl.lib libdl.exp \
 		tmptest.c tmptest.dll \
-		test.exe testdll.dll
+		test.exe testdll.dll testdll3.dll
 
 distclean: clean
 	rm -f config.mak
diff --git a/cmake-test/CMakeLists.txt b/cmake-test/CMakeLists.txt
index 532f2b8..b853920 100644
--- a/cmake-test/CMakeLists.txt
+++ b/cmake-test/CMakeLists.txt
@@ -8,6 +8,8 @@ find_package(dlfcn-win32 REQUIRED)
 
 add_library(testdll SHARED ../testdll.c)
 set_target_properties(testdll PROPERTIES PREFIX "")
+add_library(testdll3 SHARED ../testdll3.c)
+set_target_properties(testdll3 PROPERTIES PREFIX "")
 add_executable(t_dlfcn ../test.c)
 target_link_libraries(t_dlfcn dlfcn-win32::dl)
 enable_testing()
diff --git a/dlfcn.c b/dlfcn.c
index b356558..1e706f0 100644
--- a/dlfcn.c
+++ b/dlfcn.c
@@ -2,6 +2,7 @@
  * dlfcn-win32
  * Copyright (c) 2007 Ramiro Polla
  * Copyright (c) 2015 Tiancheng "Timothy" Gu
+ * Copyright (c) 2019 Pali Rohár <pali.rohar@gmail.com>
  *
  * dlfcn-win32 is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -52,57 +53,48 @@
  * any kind of thread safety.
  */
 
-typedef struct global_object {
+typedef struct local_object {
     HMODULE hModule;
-    struct global_object *previous;
-    struct global_object *next;
-} global_object;
+    struct local_object *previous;
+    struct local_object *next;
+} local_object;
 
-static global_object first_object;
-static global_object first_automatic_object;
-static int auto_ref_count = 0;
+static local_object first_object;
 
-/* These functions implement a double linked list for the global objects. */
-static global_object *global_search( global_object *start, HMODULE hModule )
+/* These functions implement a double linked list for the local objects. */
+static local_object *local_search( HMODULE hModule )
 {
-    global_object *pobject;
+    local_object *pobject;
 
     if( hModule == NULL )
         return NULL;
 
-    for( pobject = start; pobject; pobject = pobject->next )
+    for( pobject = &first_object; pobject; pobject = pobject->next )
         if( pobject->hModule == hModule )
             return pobject;
 
     return NULL;
 }
 
-static void global_add( global_object *start, HMODULE hModule )
+static void local_add( HMODULE hModule )
 {
-    global_object *pobject;
-    global_object *nobject;
+    local_object *pobject;
+    local_object *nobject;
 
     if( hModule == NULL )
         return;
 
-    pobject = global_search( start, hModule );
+    pobject = local_search( hModule );
 
     /* Do not add object again if it's already on the list */
     if( pobject )
         return;
 
-    if( start == &first_automatic_object )
-    {
-        pobject = global_search( &first_object, hModule );
-        if( pobject )
-            return;
-    }
-
-    for( pobject = start; pobject->next; pobject = pobject->next );
+    for( pobject = &first_object; pobject->next; pobject = pobject->next );
 
-    nobject = (global_object*) malloc( sizeof( global_object ) );
+    nobject = (local_object*) malloc( sizeof( local_object ) );
 
-    /* Should this be enough to fail global_add, and therefore also fail
+    /* Should this be enough to fail local_add, and therefore also fail
      * dlopen?
      */
     if( !nobject )
@@ -114,14 +106,14 @@ static void global_add( global_object *start, HMODULE hModule )
     nobject->hModule = hModule;
 }
 
-static void global_rem( global_object *start, HMODULE hModule )
+static void local_rem( HMODULE hModule )
 {
-    global_object *pobject;
+    local_object *pobject;
 
     if( hModule == NULL )
         return;
 
-    pobject = global_search( start, hModule );
+    pobject = local_search( hModule );
 
     if( !pobject )
         return;
@@ -224,10 +216,6 @@ void *dlopen( const char *file, int mode )
 
     if( file == 0 )
     {
-        HMODULE hAddtnlMods[1024]; // Already loaded modules
-        HANDLE hCurrentProc = GetCurrentProcess( );
-        DWORD cbNeeded;
-
         /* POSIX says that if the value of file is 0, a handle on a global
          * symbol object must be provided. That object must be able to access
          * all symbols from the original program file, and any objects loaded
@@ -242,27 +230,13 @@ void *dlopen( const char *file, int mode )
 
         if( !hModule )
             save_err_ptr_str( file );
-
-
-        /* GetModuleHandle( NULL ) only returns the current program file. So
-         * if we want to get ALL loaded module including those in linked DLLs,
-         * we have to use EnumProcessModules( ).
-         */
-        if( EnumProcessModules( hCurrentProc, hAddtnlMods,
-            sizeof( hAddtnlMods ), &cbNeeded ) != 0 )
-        {
-            DWORD i;
-            for( i = 0; i < cbNeeded / sizeof( HMODULE ); i++ )
-            {
-                global_add( &first_automatic_object, hAddtnlMods[i] );
-            }
-        }
-        auto_ref_count++;
     }
     else
     {
+        HANDLE hCurrentProc;
+        DWORD dwProcModsBefore, dwProcModsAfter;
         CHAR lpFileName[MAX_PATH];
-        int i;
+        size_t i;
 
         /* MSDN says backslashes *must* be used instead of forward slashes. */
         for( i = 0 ; i < sizeof(lpFileName) - 1 ; i ++ )
@@ -276,6 +250,11 @@ void *dlopen( const char *file, int mode )
         }
         lpFileName[i] = '\0';
 
+        hCurrentProc = GetCurrentProcess( );
+
+        if( EnumProcessModules( hCurrentProc, NULL, 0, &dwProcModsBefore ) == 0 )
+            dwProcModsBefore = 0;
+
         /* POSIX says the search path is implementation-defined.
          * LOAD_WITH_ALTERED_SEARCH_PATH is used to make it behave more closely
          * to UNIX's search paths (start with system folders instead of current
@@ -284,17 +263,24 @@ void *dlopen( const char *file, int mode )
         hModule = LoadLibraryEx(lpFileName, NULL, 
                                 LOAD_WITH_ALTERED_SEARCH_PATH );
 
-        /* If the object was loaded with RTLD_GLOBAL, add it to list of global
-         * objects, so that its symbols may be retrieved even if the handle for
+        if( EnumProcessModules( hCurrentProc, NULL, 0, &dwProcModsAfter ) == 0 )
+            dwProcModsAfter = 0;
+
+        /* If the object was loaded with RTLD_LOCAL, add it to list of local
+         * objects, so that its symbols cannot be retrieved even if the handle for
          * the original program file is passed. POSIX says that if the same
          * file is specified in multiple invocations, and any of them are
          * RTLD_GLOBAL, even if any further invocations use RTLD_LOCAL, the
-         * symbols will remain global.
+         * symbols will remain global. If number of loaded modules was not
+         * changed after calling LoadLibraryEx(), it means that library was
+         * already loaded.
          */
         if( !hModule )
             save_err_str( lpFileName );
-        else if( (mode & RTLD_GLOBAL) )
-            global_add( &first_object, hModule );
+        else if( (mode & RTLD_LOCAL) && dwProcModsBefore != dwProcModsAfter )
+            local_add( hModule );
+        else if( !(mode & RTLD_LOCAL) && dwProcModsBefore == dwProcModsAfter )
+            local_rem( hModule );
     }
 
     /* Return to previous state of the error-mode bit flags. */
@@ -303,21 +289,6 @@ void *dlopen( const char *file, int mode )
     return (void *) hModule;
 }
 
-static void free_auto( )
-{
-    global_object *pobject = first_automatic_object.next;
-    if( pobject )
-    {
-        global_object *next;
-        for ( ; pobject; pobject = next )
-        {
-            next = pobject->next;
-            free( pobject );
-        }
-        first_automatic_object.next = NULL;
-    }
-}
-
 int dlclose( void *handle )
 {
     HMODULE hModule = (HMODULE) handle;
@@ -327,22 +298,11 @@ int dlclose( void *handle )
 
     ret = FreeLibrary( hModule );
 
-    /* If the object was loaded with RTLD_GLOBAL, remove it from list of global
+    /* If the object was loaded with RTLD_LOCAL, remove it from list of local
      * objects.
      */
     if( ret )
-    {
-        HMODULE cur = GetModuleHandle( NULL );
-        global_rem( &first_object, hModule );
-        if( hModule == cur )
-        {
-            auto_ref_count--;
-            if( auto_ref_count < 0 )
-                auto_ref_count = 0;
-            if( !auto_ref_count )
-                free_auto( );
-        }
-    }
+        local_rem( hModule );
     else
         save_err_ptr_str( handle );
 
@@ -356,6 +316,7 @@ void *dlsym( void *handle, const char *name )
 {
     FARPROC symbol;
     HMODULE hModule;
+    HANDLE hCurrentProc;
 
 #ifdef UNICODE
     wchar_t namew[MAX_PATH];
@@ -363,6 +324,7 @@ void *dlsym( void *handle, const char *name )
 #endif
 
     current_error = NULL;
+    hCurrentProc = GetCurrentProcess( );
 
     symbol = GetProcAddress( (HMODULE) handle, name );
 
@@ -377,25 +339,33 @@ void *dlsym( void *handle, const char *name )
 
     if( hModule == handle )
     {
-        global_object *pobject;
-
-        for( pobject = &first_object; pobject; pobject = pobject->next )
-        {
-            if( pobject->hModule )
-            {
-                symbol = GetProcAddress( pobject->hModule, name );
-                if( symbol != NULL )
-                    goto end;
-            }
-        }
+        HMODULE *modules;
+        DWORD cbNeeded;
+        DWORD dwSize;
+        size_t i;
 
-        for( pobject = &first_automatic_object; pobject; pobject = pobject->next )
+        /* GetModuleHandle( NULL ) only returns the current program file. So
+         * if we want to get ALL loaded module including those in linked DLLs,
+         * we have to use EnumProcessModules( ).
+         */
+        if( EnumProcessModules( hCurrentProc, NULL, 0, &dwSize ) != 0 )
         {
-            if( pobject->hModule )
+            modules = malloc( dwSize );
+            if( modules )
             {
-                symbol = GetProcAddress( pobject->hModule, name );
-                if( symbol != NULL )
-                    goto end;
+                if( EnumProcessModules( hCurrentProc, modules, dwSize, &cbNeeded ) != 0 && dwSize == cbNeeded )
+                {
+                    for( i = 0; i < dwSize / sizeof( HMODULE ); i++ )
+                    {
+                        if( local_search( modules[i] ) )
+                            continue;
+                        symbol = GetProcAddress( modules[i], name );
+                        if( symbol != NULL )
+                            goto end;
+                    }
+
+                }
+                free( modules );
             }
         }
     }
@@ -472,18 +442,8 @@ char *dlerror( void )
 BOOL WINAPI DllMain( HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved )
 {
     (void) hinstDLL;
-    /*
-     * https://msdn.microsoft.com/en-us/library/windows/desktop/ms682583(v=vs.85).aspx 
-     *
-     *     When handling DLL_PROCESS_DETACH, a DLL should free resources such as heap
-     *     memory only if the DLL is being unloaded dynamically (the lpReserved
-     *     parameter is NULL).
-     */
-    if( fdwReason == DLL_PROCESS_DETACH && !lpvReserved )
-    {
-        auto_ref_count = 0;
-        free_auto( );
-    }
+    (void) fdwReason;
+    (void) lpvReserved;
     return TRUE;
 }
 #endif
diff --git a/test.c b/test.c
index ba440da..10c655e 100644
--- a/test.c
+++ b/test.c
@@ -2,6 +2,7 @@
  * dlfcn-win32
  * Copyright (c) 2007-2009 Ramiro Polla
  * Copyright (c) 2014      Tiancheng "Timothy" Gu
+ * Copyright (c) 2019      Pali Rohár <pali.rohar@gmail.com>
  *
  * dlfcn-win32 is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -25,6 +26,7 @@
 #endif
 #include <stdio.h>
 #include <string.h>
+#include <windows.h>
 #include "dlfcn.h"
 
 /* If these dlclose's fails, we don't care as the handles are going to be
@@ -77,6 +79,7 @@ int main()
     size_t (*fwrite_local) ( const void *, size_t, size_t, FILE * );
     int (*nonexistentfunction)( void );
     int ret;
+    HMODULE library3;
 
 #ifdef _DEBUG
     _CrtSetReportMode(_CRT_WARN, _CRTDBG_MODE_FILE);
@@ -335,6 +338,15 @@ int main()
         printf("SUCCESS\tGot symbol from global handle: %p\n", function);
     
 
+    library3 = LoadLibraryA("testdll3.dll");
+    if (!library3)
+    {
+        printf( "ERROR\tCould not open library3 via WINAPI\n" );
+        RETURN_ERROR;
+    }
+    else
+        printf( "SUCCESS\tOpened library3 via WINAPI: %p\n", library3 );
+
     ret = dlclose( library );
     if( ret )
     {
@@ -346,6 +358,21 @@ int main()
     else
         printf( "SUCCESS\tClosed library.\n" );
 
+    function = dlsym(global, "function3");
+    if (!function)
+    {
+        error = dlerror();
+        printf("ERROR\tCould not get symbol from global handle: %s\n",
+            error ? error : "");
+        CLOSE_LIB;
+        CLOSE_GLOBAL;
+        RETURN_ERROR;
+    }
+    else
+        printf("SUCCESS\tGot symbol from global handle: %p\n", function);
+
+    RUNFUNC;
+
     ret = dlclose( global );
     if( ret )
     {
diff --git a/testdll3.c b/testdll3.c
new file mode 100644
index 0000000..3906e48
--- /dev/null
+++ b/testdll3.c
@@ -0,0 +1,38 @@
+/*
+ * dlfcn-win32
+ * Copyright (c) 2007 Ramiro Polla
+ * Copyright (c) 2019 Pali Rohár <pali.rohar@gmail.com>
+ *
+ * dlfcn-win32 is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * dlfcn-win32 is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with dlfcn-win32; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#ifdef _DEBUG
+#define _CRTDBG_MAP_ALLOC
+#include <stdlib.h>
+#include <crtdbg.h>
+#endif
+#include <stdio.h>
+
+#if defined(_WIN32)
+#define EXPORT __declspec(dllexport)
+#else
+#define EXPORT
+#endif
+
+EXPORT int function3( void )
+{
+    printf( "Hello, world!\n" );
+    return 0;
+}