Index: openmp/trunk/runtime/CMakeLists.txt
===================================================================
--- openmp/trunk/runtime/CMakeLists.txt
+++ openmp/trunk/runtime/CMakeLists.txt
@@ -273,7 +273,6 @@
 endif()
 
 # OMPT-support
-# TODO: Make this a real feature check
 set(LIBOMP_OMPT_SUPPORT FALSE CACHE BOOL
   "OMPT-support?")
 set(LIBOMP_OMPT_BLAME TRUE CACHE BOOL
Index: openmp/trunk/runtime/cmake/LibompMicroTests.cmake
===================================================================
--- openmp/trunk/runtime/cmake/LibompMicroTests.cmake
+++ openmp/trunk/runtime/cmake/LibompMicroTests.cmake
@@ -175,6 +175,7 @@
   set(libomp_expected_library_deps /usr/lib/libSystem.B.dylib)
 elseif(WIN32)
   set(libomp_expected_library_deps kernel32.dll)
+  libomp_append(libomp_expected_library_deps psapi.dll LIBOMP_OMPT_SUPPORT)
 else()
   if(${MIC})
     set(libomp_expected_library_deps libc.so.6 libpthread.so.0 libdl.so.2)
Index: openmp/trunk/runtime/cmake/config-ix.cmake
===================================================================
--- openmp/trunk/runtime/cmake/config-ix.cmake
+++ openmp/trunk/runtime/cmake/config-ix.cmake
@@ -13,6 +13,7 @@
 include(CheckCSourceCompiles)
 include(CheckCXXCompilerFlag)
 include(CheckLibraryExists)
+include(CheckIncludeFiles)
 include(LibompCheckLinkerFlag)
 include(LibompCheckFortranFlag)
 
@@ -187,8 +188,26 @@
 endif()
 
 # Check if OMPT support is available
-if(NOT WIN32)
-  set(LIBOMP_HAVE_OMPT_SUPPORT TRUE)
-else()
+# Currently, __builtin_frame_address() is required for OMPT
+# Weak attribute is required for Unices, LIBPSAPI is used for Windows
+check_c_source_compiles("int main(int argc, char** argv) {
+  void* p = __builtin_frame_address(0);
+  return 0;}" LIBOMP_HAVE___BUILTIN_FRAME_ADDRESS)
+check_c_source_compiles("__attribute__ ((weak)) int foo(int a) { return a*a; }
+  int main(int argc, char** argv) {
+  return foo(argc);}" LIBOMP_HAVE_WEAK_ATTRIBUTE)
+check_include_files("windows.h;psapi.h" LIBOMP_HAVE_PSAPI_H)
+check_library_exists(psapi EnumProcessModules "" LIBOMP_HAVE_LIBPSAPI)
+if(LIBOMP_HAVE_PSAPI_H AND LIBOMP_HAVE_LIBPSAPI)
+  set(LIBOMP_HAVE_PSAPI TRUE)
+endif()
+if(NOT LIBOMP_HAVE___BUILTIN_FRAME_ADDRESS)
   set(LIBOMP_HAVE_OMPT_SUPPORT FALSE)
+else()
+  if(LIBOMP_HAVE_WEAK_ATTRIBUTE OR LIBOMP_HAVE_PSAPI)
+    set(LIBOMP_HAVE_OMPT_SUPPORT TRUE)
+  else()
+    set(LIBOMP_HAVE_OMPT_SUPPORT FALSE)
+  endif()
 endif()
+
Index: openmp/trunk/runtime/src/kmp_config.h.cmake
===================================================================
--- openmp/trunk/runtime/src/kmp_config.h.cmake
+++ openmp/trunk/runtime/src/kmp_config.h.cmake
@@ -27,6 +27,10 @@
 #if LIBOMP_USE_VERSION_SYMBOLS
 # define KMP_USE_VERSION_SYMBOLS
 #endif
+#cmakedefine01 LIBOMP_HAVE_WEAK_ATTRIBUTE
+#define KMP_HAVE_WEAK_ATTRIBUTE LIBOMP_HAVE_WEAK_ATTRIBUTE
+#cmakedefine01 LIBOMP_HAVE_PSAPI
+#define KMP_HAVE_PSAPI LIBOMP_HAVE_PSAPI
 #cmakedefine01 LIBOMP_STATS
 #define KMP_STATS_ENABLED LIBOMP_STATS
 #cmakedefine01 LIBOMP_USE_DEBUGGER
Index: openmp/trunk/runtime/src/ompt-general.c
===================================================================
--- openmp/trunk/runtime/src/ompt-general.c
+++ openmp/trunk/runtime/src/ompt-general.c
@@ -15,7 +15,6 @@
  * ompt include files
  ****************************************************************************/
 
-#include "kmp_config.h"
 #include "ompt-internal.h"
 #include "ompt-specific.c"
 
@@ -32,6 +31,9 @@
 
 #define OMPT_API_ROUTINE static
 
+#ifndef OMPT_STR_MATCH
+#define OMPT_STR_MATCH(haystack, needle) (!strcasecmp(haystack, needle))
+#endif
 
 
 /*****************************************************************************
@@ -87,17 +89,93 @@
 OMPT_API_ROUTINE ompt_thread_id_t ompt_get_thread_id(void);
 
 
-
 /*****************************************************************************
  * initialization and finalization (private operations)
  ****************************************************************************/
 
-_OMP_EXTERN __attribute__ (( weak ))
+/* On Unix-like systems that support weak symbols the following implementation
+ * of ompt_tool() will be used in case no tool-supplied implementation of
+ * this function is present in the address space of a process.
+ *
+ * On Windows, the ompt_tool_windows function is used to find the
+ * ompt_tool symbol across all modules loaded by a process. If ompt_tool is
+ * found, ompt_tool's return value is used to initialize the tool. Otherwise,
+ * NULL is returned and OMPT won't be enabled */
+#if OMPT_HAVE_WEAK_ATTRIBUTE
+_OMP_EXTERN 
+__attribute__ (( weak ))
 ompt_initialize_t ompt_tool()
 {
+#if OMPT_DEBUG
+    printf("ompt_tool() is called from the RTL\n");
+#endif
     return NULL;
 }
 
+#elif OMPT_HAVE_PSAPI
+
+#include <psapi.h>
+#pragma comment(lib, "psapi.lib")
+#define ompt_tool ompt_tool_windows
+
+// The number of loaded modules to start enumeration with EnumProcessModules()
+#define NUM_MODULES 128
+
+static
+ompt_initialize_t ompt_tool_windows()
+{
+    int i;
+    DWORD needed, new_size;
+    HMODULE *modules;
+    HANDLE  process = GetCurrentProcess();
+    modules = (HMODULE*)malloc( NUM_MODULES * sizeof(HMODULE) );
+    ompt_initialize_t (*ompt_tool_p)() = NULL;
+
+#if OMPT_DEBUG
+    printf("ompt_tool_windows(): looking for ompt_tool\n");
+#endif
+    if( !EnumProcessModules( process, modules, NUM_MODULES * sizeof(HMODULE),
+                             &needed ) ) {
+        // Regardless of the error reason use the stub initialization function
+        return NULL;
+    }
+    // Check if NUM_MODULES is enough to list all modules
+    new_size = needed / sizeof(HMODULE);
+    if( new_size > NUM_MODULES ) {
+#if OMPT_DEBUG
+    printf("ompt_tool_windows(): resize buffer to %d bytes\n", needed);
+#endif
+        modules = (HMODULE*)realloc( modules, needed );
+        // If resizing failed use the stub function.
+        if( !EnumProcessModules( process, modules, needed, &needed ) ) {
+            return NULL;
+        }
+    }
+    for( i = 0; i < new_size; ++i ) {
+        (FARPROC &)ompt_tool_p = GetProcAddress(modules[i], "ompt_tool");
+        if( ompt_tool_p ) {
+#if OMPT_DEBUG
+            TCHAR modName[MAX_PATH];
+            if( GetModuleFileName(modules[i], modName, MAX_PATH))
+                printf("ompt_tool_windows(): ompt_tool found in module %s\n",
+                       modName);
+#endif
+            return ompt_tool_p();
+        }
+#if OMPT_DEBUG
+        else {
+            TCHAR modName[MAX_PATH];
+            if( GetModuleFileName(modules[i], modName, MAX_PATH) )
+                printf("ompt_tool_windows(): ompt_tool not found in module %s\n",
+                       modName);
+        }
+#endif
+    }
+    return NULL;
+}
+#else
+# error Either __attribute__((weak)) or psapi.dll are required for OMPT support
+#endif // OMPT_HAVE_WEAK_ATTRIBUTE
 
 void ompt_pre_init()
 {
@@ -118,11 +196,14 @@
 
     if (!ompt_env_var  || !strcmp(ompt_env_var, ""))
         tool_setting = omp_tool_unset;
-    else if (!strcasecmp(ompt_env_var, "disabled"))
+    else if (OMPT_STR_MATCH(ompt_env_var, "disabled"))
         tool_setting = omp_tool_disabled;
-    else if (!strcasecmp(ompt_env_var, "enabled"))
+    else if (OMPT_STR_MATCH(ompt_env_var, "enabled"))
         tool_setting = omp_tool_enabled;
 
+#if OMPT_DEBUG
+    printf("ompt_pre_init(): tool_setting = %d\n", tool_setting);
+#endif
     switch(tool_setting) {
     case omp_tool_disabled:
         break;
@@ -142,7 +223,9 @@
             "\"enabled\").\n", ompt_env_var);
         break;
     }
-
+#if OMPT_DEBUG
+    printf("ompt_pre_init():ompt_enabled = %d\n", ompt_enabled);
+#endif
 }
 
 
Index: openmp/trunk/runtime/src/ompt-specific.h
===================================================================
--- openmp/trunk/runtime/src/ompt-specific.h
+++ openmp/trunk/runtime/src/ompt-specific.h
@@ -34,6 +34,14 @@
 ompt_frame_t *__ompt_get_task_frame_internal(int depth);
 
 
+/*****************************************************************************
+ * macros
+ ****************************************************************************/
+#define OMPT_DEBUG KMP_DEBUG
+#define OMPT_HAVE_WEAK_ATTRIBUTE KMP_HAVE_WEAK_ATTRIBUTE
+#define OMPT_HAVE_PSAPI KMP_HAVE_PSAPI
+#define OMPT_STR_MATCH(haystack, needle) __kmp_str_match(haystack, 0, needle)
+
 
 //******************************************************************************
 // inline functions
Index: openmp/trunk/runtime/src/ompt-specific.c
===================================================================
--- openmp/trunk/runtime/src/ompt-specific.c
+++ openmp/trunk/runtime/src/ompt-specific.c
@@ -29,7 +29,7 @@
 #define NEXT_ID(id_ptr,tid) \
   ((KMP_TEST_THEN_INC64(id_ptr) << OMPT_THREAD_ID_BITS) | (tid))
 #else
-#define NEXT_ID(id_ptr,tid) (KMP_TEST_THEN_INC64(id_ptr))
+#define NEXT_ID(id_ptr,tid) (KMP_TEST_THEN_INC64((volatile kmp_int64 *)id_ptr))
 #endif
 
 //******************************************************************************