Several changes:

 - Merges from master:
  - Make WPopupMenu pop up above other popups
  - Added support for using libunwind to print stacktraces

Author: RockinRoel

CMakeLists.txt

@@ -115,6 +115,7 @@ OPTION(WT_NO_STD_LOCALE "Build Wt to run on a system without std::locale support
 OPTION(WT_NO_STD_WSTRING "Build Wt to run on a system without std::wstring support" OFF)
 OPTION(ENABLE_OPENGL "Build Wt with support for server-side opengl rendering" ON)
 OPTION(WT_WARN_HEADER_MISSING_H "Output a warning if a Wt header without .h extension is included (deprecated since Wt 4.0.0)" ON)
+OPTION(ENABLE_UNWIND "Build Wt with stacktrace support using libunwind" OFF)
 
 IF(NOT CMAKE_CXX_STANDARD)
   SET(CMAKE_CXX_STANDARD 11)
@@ -290,6 +291,8 @@ SET(SKIA_PREFIX ${USERLIB_PREFIX} CACHE PATH
   "Prefix of skia library (overrides USERLIB_PREFIX)")
 SET(ASIO_PREFIX ${USERLIB_PREFIX} CACHE PATH
   "Prefix of Asio (overrides USERLIB_PREFIX), only used when WT_ASIO_IMPLEMENTATION is standalone")
+SET(UNWIND_PREFIX ${UNWIND_PREFIX} CACHE PATH
+  "Prefix of unwind library (overrides USERLIB_PREFIX)")
 
 OPTION(DEBUG "Support for debugging, must be enabled also in wt_config.xml" OFF)
 
@@ -338,6 +341,10 @@ INCLUDE(cmake/WtFindGm.txt)
 INCLUDE(cmake/WtFindGL.txt)
 INCLUDE(cmake/WtFindSkia.txt)
 
+IF (ENABLE_UNWIND)
+  INCLUDE(cmake/WtFindUnwind.txt)
+ENDIF (ENABLE_UNWIND)
+
 IF (ENABLE_PANGO)
   INCLUDE(cmake/WtFindPangoFt2.txt)
 ENDIF (ENABLE_PANGO)
@@ -615,6 +622,10 @@ IF(ENABLE_OPENGL AND GL_FOUND AND WT_HAS_WRASTERIMAGE)
   SET(HAVE_GL TRUE)
 ENDIF(ENABLE_OPENGL AND GL_FOUND AND WT_HAS_WRASTERIMAGE)
 
+IF(ENABLE_UNWIND AND UNWIND_FOUND)
+  SET(HAVE_UNWIND ON)
+ENDIF(ENABLE_UNWIND AND UNWIND_FOUND)
+
 # Compile time constants & make sure our build finds it
 FILE(MAKE_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/Wt)
 SET(WCONFIG_H_PATH ${CMAKE_CURRENT_BINARY_DIR}/Wt/WConfig.h)

cmake/WtFindUnwind.txt

@@ -0,0 +1,20 @@
+FIND_PATH(UNWIND_INCLUDE libunwind.h
+  ${UNWIND_PREFIX}/include
+  /usr/include
+)
+
+FIND_LIBRARY(UNWIND_LIB
+  NAMES
+      unwind
+  PATHS
+      ${UNWIND_PREFIX}/lib
+      /usr/lib
+  )
+
+IF(UNWIND_INCLUDE AND UNWIND_LIB)
+  SET(UNWIND_FOUND TRUE)
+  SET(UNWIND_INCLUDE_DIRS ${UNWIND_INCLUDE})
+  SET(UNWIND_LIBRARIES ${UNWIND_LIB})
+ELSE(UNWIND_INCLUDE AND UNWIND_LIB)
+  SET(UNWIND_FOUND FALSE)
+ENDIF(UNWIND_INCLUDE AND UNWIND_LIB)

src/CMakeLists.txt

@@ -579,6 +579,17 @@ ELSEIF(WT_FONTSUPPORT_DIRECTWRITE)
   MESSAGE("** Enabling advanced font support using DirectWrite")
 ENDIF(WT_FONTSUPPORT_SIMPLE)
 
+IF(HAVE_UNWIND)
+  ADD_DEFINITIONS(-DWT_WITH_UNWIND)
+  TARGET_LINK_LIBRARIES(wt PRIVATE ${UNWIND_LIBRARIES})
+  INCLUDE_DIRECTORIES(${UNWIND_INCLUDE_DIRS})
+  MESSAGE("** Enabling stacktrace prints using libunwind")
+ELSE(HAVE_UNWIND)
+  IF(ENABLE_UNWIND)
+    MESSAGE("** Disabling stacktrace prints: could not find libunwind")
+  ENDIF(ENABLE_UNWIND)
+ENDIF(HAVE_UNWIND)
+
 IF(MULTI_THREADED_BUILD)
   TARGET_LINK_LIBRARIES(wt PRIVATE ${CMAKE_THREAD_LIBS_INIT})
 ENDIF(MULTI_THREADED_BUILD)

src/Wt/Auth/Dbo/UserDatabase

@@ -10,6 +10,7 @@
 #include <Wt/Auth/AbstractUserDatabase.h>
 #include <Wt/Auth/AuthService.h>
 #include <Wt/Auth/Dbo/AuthInfo.h>
+#include <Wt/WException.h>
 #include <Wt/WLogger.h>
 
 namespace Wt {
@@ -298,7 +299,7 @@ public:
     if (session_.find<AuthTokenType>().where("\"value\" = ?")
 	.bind(token.hash())
 	.resultList().size() > 0)
-      throw std::runtime_error("Token hash collision");
+      throw WException("Token hash collision");
 
     /*
      * Prevent a user from piling up the database with tokens

src/Wt/Auth/HashFunction.C

@@ -100,12 +100,12 @@ std::string BCryptHashFunction::compute(const std::string& msg,
 
   if (!crypt_gensalt_rn("$2y$", count_, c_salt, 16, setting, 32)) {
     std::perror("crypt_gen_salt_rn");
-    throw std::runtime_error("bcrypt() gensalt internal error");
+    throw WException("bcrypt() gensalt internal error");
   } else {
     char result[64];
     if (!crypt_rn(msg.c_str(), setting, result, 64)) {
       std::perror("crypt_rn");
-      throw std::runtime_error("bcrypt() internal error");
+      throw WException("bcrypt() internal error");
     }
     return result;
   }
@@ -119,7 +119,7 @@ bool BCryptHashFunction::verify(const std::string& msg,
 
   if (!crypt_rn(msg.c_str(), hash.c_str(), result, 64)) {
     std::perror("crypt_rn");
-    throw std::runtime_error("bcrypt() internal error");
+    throw WException("bcrypt() internal error");
   }
 
   return result == hash;

src/Wt/Dbo/CMakeLists.txt

@@ -31,6 +31,10 @@ IF(ENABLE_LIBWTDBO)
     StringStream.C
   )
 
+  IF(HAVE_UNWIND)
+    TARGET_LINK_LIBRARIES(wtdbo PRIVATE ${UNWIND_LIBRARIES})
+  ENDIF(HAVE_UNWIND)
+
   IF(MSVC)
     #win32 links automatically against boost libs; specifying too much causes
     #trouble

src/Wt/Dbo/Exception

@@ -14,6 +14,8 @@
 namespace Wt {
   namespace Dbo {
 
+extern WTDBO_API std::string backtrace();
+
 /*! \class Exception Wt/Dbo/Exception.h Wt/Dbo/Exception.h
  *  \brief %Exception base class for %Wt::%Dbo.
  *

src/Wt/Dbo/Exception.C

@@ -6,13 +6,86 @@
 
 #include "Wt/Dbo/Exception.h"
 
+#ifdef WT_WITH_UNWIND
+#define UNW_LOCAL_ONLY
+
+#include <cxxabi.h>
+#include <libunwind.h>
+#include <cstdio>
+#include <cstdlib>
+
+namespace Wt {
+  namespace Dbo {
+
+std::string backtrace() {
+  unw_cursor_t cursor;
+  unw_context_t context;
+
+  // Initialize cursor to current frame for local unwinding.
+  unw_getcontext(&context);
+  unw_init_local(&cursor, &context);
+
+  std::stringstream ss;
+  
+  // Unwind frames one by one, going up the frame stack.
+  while (unw_step(&cursor) > 0) {
+    unw_word_t offset, pc;
+    unw_get_reg(&cursor, UNW_REG_IP, &pc);
+    if (pc == 0) {
+      break;
+    }
+
+    ss << "0x" << std::hex << pc;
+    
+    char sym[256];
+    if (unw_get_proc_name(&cursor, sym, sizeof(sym), &offset) == 0) {
+      char* nameptr = sym;
+      int status;
+      char* demangled = abi::__cxa_demangle(sym, nullptr, nullptr, &status);
+      if (status == 0) {
+        nameptr = demangled;
+      }
+
+      ss << " (" << nameptr << "+0x" << std::hex << offset << ")" << std::endl;
+      
+      std::free(demangled);
+    } else {
+      ss << " -- error: unable to obtain symbol name for this frame" << std::endl;
+    }
+  }
+
+  return ss.str();
+}
+
+  }
+}
+
+#else
+
+namespace Wt {
+  namespace Dbo {
+
+std::string backtrace() {
+  return "N/A";
+}
+
+  }
+}
+
+#endif
+
 namespace Wt {
   namespace Dbo {
 
 Exception::Exception(const std::string& error, const std::string& code)
+#ifdef WT_WITH_UNWIND
+  : std::runtime_error(error + " at\n" + backtrace()),
+#else
   : std::runtime_error(error),
+#endif
     code_(code)
-{ }
+{
+}
 
 Exception::~Exception() throw() { }
 

src/Wt/Dbo/QueryModel_impl.h

@@ -286,7 +286,6 @@ void QueryModel<Result>::cacheRow(int row) const
 
     Transaction transaction(query_.session());
 
-    std::cerr << "Fetching offset=" << qOffset << ", limit=" << qLimit << std::endl;
     collection<Result> results = query_.resultList();
     cache_.clear();
     cache_.insert(cache_.end(), results.begin(), results.end());   

src/Wt/Dbo/Transaction.C

@@ -54,7 +54,7 @@ Transaction::~Transaction() noexcept(false)
 	  if (impl_->transactionCount_ == 1)
 	    rollback();
 	} catch (...) {
-	  std::cerr << "Unexpected transaction during Transaction::rollback()"
+	  std::cerr << "Unexpected exception during Transaction::rollback()"
 		    << std::endl;
 	}