Further improve the working of the exception mechanism.

git-svn-id: https://svn.dealii.org/trunk@5370 0785d39b-7218-0410-832d-ea1e28bc413d

diff --git a/deal.II/base/include/base/exceptions.h b/deal.II/base/include/base/exceptions.h
index e0c21fbc882569203b00800a32a0f27b5c576621..3fade7e8f56819001c087200354cb7ed91e30ee3 100644 (file)
--- a/deal.II/base/include/base/exceptions.h
+++ b/deal.II/base/include/base/exceptions.h
@@ -180,6 +180,12 @@
  *  not terminate the program to allow that the thrown exception
  *  propagates to some place where its message can be displayed.
  *
+ *  Since it is common that one failed assertion leads to a whole
+ *  chain of others, we only ever print the very first message. If the
+ *  program is then aborted, that is no problem. If it is not (since a
+ *  C++ exception is active), only the first is displayed and a
+ *  message about suppressed follow-up messages is shown.
+ *
  *
  *  @sect2{Use of run-time exceptions}
  *
@@ -394,6 +400,28 @@ class ExceptionBase : public std::exception
                                      * Name of the exception and call sequence.
                                      */
     const char  *exc;
+
+                                    /**
+                                     * Number of exceptions dealt
+                                     * with so far. Zero at program
+                                     * start. Messages are only
+                                     * displayed if the value is
+                                     * zero.
+                                     */
+    static unsigned int n_treated_exceptions;
+
+                                    /**
+                                     * Make this function a friend
+                                     * since it needs access to the
+                                     * @p{n_treated_exceptions}
+                                     * variable.
+                                     */
+    template <class exc> friend void __IssueError_Assert (const char *file,
+                                                         int         line,
+                                                         const char *function,
+                                                         const char *cond,
+                                                         const char *exc_name,
+                                                         exc         e);
 };
 
 
@@ -413,16 +441,37 @@ void __IssueError_Assert (const char *file,
                          const char *exc_name,
                          exc         e)
 {
-                                  // Fill the fields of the exception object
+                                  // fill the fields of the exception object
   e.SetFields (file, line, function, cond, exc_name);
-  std::cerr << "--------------------------------------------------------"
-           << std::endl;
-                                  // print out general data
-  e.PrintExcData (std::cerr);
-                                  // print out exception specific data
-  e.PrintInfo (std::cerr);
-  std::cerr << "--------------------------------------------------------"
-           << std::endl;
+
+                                  // if no other exception has been
+                                  // displayed before, show this one
+  if (ExceptionBase::n_treated_exceptions == 0)
+    {
+      std::cerr << "--------------------------------------------------------"
+               << std::endl;
+                                      // print out general data
+      e.PrintExcData (std::cerr);
+                                      // print out exception specific data
+      e.PrintInfo (std::cerr);
+      std::cerr << "--------------------------------------------------------"
+               << std::endl;
+    }
+  else
+    {
+                                      // if this is the first
+                                      // follow-up message, display a
+                                      // message that further
+                                      // exceptions are suppressed
+      if (ExceptionBase::n_treated_exceptions == 1)
+       std::cerr << "******** More assertions fail but messages are suppressed! ********"
+                 << std::endl;
+    };
+
+                                  // increase number of treated
+                                  // exceptions by one
+  ExceptionBase::n_treated_exceptions++;
+      
 
                                   // abort the program now since
                                   // something has gone horribly
@@ -435,7 +484,7 @@ void __IssueError_Assert (const char *file,
                                   // see the original exception. in
                                   // that case indicate that the
                                   // program is not aborted due to
-                                  // this reason
+                                  // this reason.
   if (std::uncaught_exception() == true)
     std::cerr << "******** Program is not aborted since another exception is active! ********"
              << std::endl;

diff --git a/deal.II/base/source/exceptions.cc b/deal.II/base/source/exceptions.cc
index 0f8eca90a20ed5ecdbe4c6670464ab834596f426..18e293694fa9d9f8babeced520168da9f0fe8266 100644 (file)
--- a/deal.II/base/source/exceptions.cc
+++ b/deal.II/base/source/exceptions.cc
@@ -25,6 +25,9 @@
 #endif
 
 
+unsigned int ExceptionBase::n_treated_exceptions;
+
+
 ExceptionBase::ExceptionBase () :
                file(""), line(0), function(""), cond(""), exc("")
 {};