From: Timo Heister <timo.heister@gmail.com>
Date: Sun, 24 Jan 2016 17:05:13 +0000 (+0100)
Subject: fix crash in petsc step-40
X-Git-Tag: v8.4.0-rc2~56^2
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=refs%2Fpull%2F2111%2Fhead;p=dealii.git

fix crash in petsc step-40

fix:

An error occurred in line <96> of file </ssd/deal-
git/source/lac/petsc_solver.cc> in function
    void dealii::PETScWrappers::SolverBase::solve(const
dealii::PETScWrappers::MatrixBase&, dealii::PETScWrappers::VectorBase&,
const dealii::PETScWrappers::VectorBase&, const
dealii::PETScWrappers::PreconditionerBase&)
The violated condition was:
    ierr == 0
The name and call sequence of the exception was:
    ExcPETScError(ierr)
Additional Information:
An error with error number 80 occurred while calling a PETSc function
---

diff --git a/examples/step-40/step-40.cc b/examples/step-40/step-40.cc
index 52b02b2bd4..3181164a2a 100644
--- a/examples/step-40/step-40.cc
+++ b/examples/step-40/step-40.cc
@@ -34,15 +34,18 @@
 // and you prefer using Trilinos in this example:
 // #define FORCE_USE_OF_TRILINOS
 
-// This will either import PETSc or TrilinosWrappers into the namespace LA:
+// This will either import PETSc or TrilinosWrappers into the namespace
+// LA. Note that we are defining the macro USE_PETSC_LA so that we can detect
+// if we are using PETSc (see solve() for an example where this is necessary)
 namespace LA
 {
 #if defined(DEAL_II_WITH_PETSC) && !(defined(DEAL_II_WITH_TRILINOS) && defined(FORCE_USE_OF_TRILINOS))
   using namespace dealii::LinearAlgebraPETSc;
+#  define USE_PETSC_LA
 #elif defined(DEAL_II_WITH_TRILINOS)
   using namespace dealii::LinearAlgebraTrilinos;
 #else
-#error DEAL_II_WITH_PETSC or DEAL_II_WITH_TRILINOS required
+#  error DEAL_II_WITH_PETSC or DEAL_II_WITH_TRILINOS required
 #endif
 }