Guard all examples to avoid errors with --disable-optional.

This way we can still run "make check" successfully even though it
doesn't really check much of anything.

examples/adaptivity/adaptivity_ex1/adaptivity_ex1.C

@@ -65,6 +65,10 @@ int main(int argc, char ** argv)
   // finalized.
   LibMeshInit init (argc, argv);
 
+  // This example requires a linear solver package.
+  libmesh_example_requires(libMesh::default_solver_package() != INVALID_SOLVER_PACKAGE,
+                           "--enable-petsc, --enable-trilinos, or --enable-eigen");
+
   // Skip adaptive examples on a non-adaptive libMesh build
 #ifndef LIBMESH_ENABLE_AMR
   libmesh_example_requires(false, "--enable-amr");

examples/adaptivity/adaptivity_ex2/adaptivity_ex2.C

@@ -119,6 +119,10 @@ int main (int argc, char ** argv)
   // Initialize libMesh.
   LibMeshInit init (argc, argv);
 
+  // This example requires a linear solver package.
+  libmesh_example_requires(libMesh::default_solver_package() != INVALID_SOLVER_PACKAGE,
+                           "--enable-petsc, --enable-trilinos, or --enable-eigen");
+
 #ifndef LIBMESH_ENABLE_AMR
   libmesh_example_requires(false, "--enable-amr");
 #else

examples/adaptivity/adaptivity_ex3/adaptivity_ex3.C

@@ -118,6 +118,10 @@ int main(int argc, char ** argv)
   // Initialize libMesh.
   LibMeshInit init (argc, argv);
 
+  // This example requires a linear solver package.
+  libmesh_example_requires(libMesh::default_solver_package() != INVALID_SOLVER_PACKAGE,
+                           "--enable-petsc, --enable-trilinos, or --enable-eigen");
+
   // Single precision is inadequate for p refinement
   libmesh_example_requires(sizeof(Real) > 4, "--disable-singleprecision");
 

examples/adaptivity/adaptivity_ex4/adaptivity_ex4.C

@@ -152,6 +152,10 @@ int main(int argc, char ** argv)
   // Initialize libMesh.
   LibMeshInit init (argc, argv);
 
+  // This example requires a linear solver package.
+  libmesh_example_requires(libMesh::default_solver_package() != INVALID_SOLVER_PACKAGE,
+                           "--enable-petsc, --enable-trilinos, or --enable-eigen");
+
   // Adaptive constraint calculations for fine Hermite elements seems
   // to require half-decent precision
 #ifdef LIBMESH_DEFAULT_SINGLE_PRECISION

examples/adaptivity/adaptivity_ex5/adaptivity_ex5.C

@@ -129,6 +129,10 @@ int main (int argc, char ** argv)
   // Initialize libMesh.
   LibMeshInit init (argc, argv);
 
+  // This example requires a linear solver package.
+  libmesh_example_requires(libMesh::default_solver_package() != INVALID_SOLVER_PACKAGE,
+                           "--enable-petsc, --enable-trilinos, or --enable-eigen");
+
   // Skip this 2D example if libMesh was compiled as 1D-only.
   libmesh_example_requires(2 <= LIBMESH_DIM, "2D support");
 

examples/adjoints/adjoints_ex1/adjoints_ex1.C

@@ -236,6 +236,10 @@ int main (int argc, char ** argv)
   // Initialize libMesh.
   LibMeshInit init (argc, argv);
 
+  // This example requires a linear solver package.
+  libmesh_example_requires(libMesh::default_solver_package() != INVALID_SOLVER_PACKAGE,
+                           "--enable-petsc, --enable-trilinos, or --enable-eigen");
+
   // Skip adaptive examples on a non-adaptive libMesh build
 #ifndef LIBMESH_ENABLE_AMR
   libmesh_example_requires(false, "--enable-amr");

examples/adjoints/adjoints_ex2/adjoints_ex2.C

@@ -236,6 +236,10 @@ int main (int argc, char ** argv)
   // Initialize libMesh.
   LibMeshInit init (argc, argv);
 
+  // This example requires a linear solver package.
+  libmesh_example_requires(libMesh::default_solver_package() != INVALID_SOLVER_PACKAGE,
+                           "--enable-petsc, --enable-trilinos, or --enable-eigen");
+
   // Skip adaptive examples on a non-adaptive libMesh build
 #ifndef LIBMESH_ENABLE_AMR
   libmesh_example_requires(false, "--enable-amr");

examples/adjoints/adjoints_ex4/adjoints_ex4.C

@@ -205,6 +205,10 @@ int main (int argc, char** argv)
   // Initialize libMesh.
   LibMeshInit init (argc, argv);
 
+  // This example requires a linear solver package.
+  libmesh_example_requires(libMesh::default_solver_package() != INVALID_SOLVER_PACKAGE,
+                           "--enable-petsc, --enable-trilinos, or --enable-eigen");
+
   // Skip adaptive examples on a non-adaptive libMesh build
 #ifndef LIBMESH_ENABLE_AMR
   libmesh_example_requires(false, "--enable-amr");

examples/fem_system/fem_system_ex1/fem_system_ex1.C

@@ -55,6 +55,10 @@ int main (int argc, char ** argv)
   // Initialize libMesh.
   LibMeshInit init (argc, argv);
 
+  // This example requires a linear solver package.
+  libmesh_example_requires(libMesh::default_solver_package() != INVALID_SOLVER_PACKAGE,
+                           "--enable-petsc, --enable-trilinos, or --enable-eigen");
+
   // This example fails without at least double precision FP
 #ifdef LIBMESH_DEFAULT_SINGLE_PRECISION
   libmesh_example_requires(false, "--disable-singleprecision");

examples/fem_system/fem_system_ex2/fem_system_ex2.C

@@ -149,6 +149,10 @@ int main(int argc, char ** argv)
   // Initialize libMesh and any dependent libraries
   LibMeshInit init(argc, argv);
 
+  // This example requires a linear solver package.
+  libmesh_example_requires(libMesh::default_solver_package() != INVALID_SOLVER_PACKAGE,
+                           "--enable-petsc, --enable-trilinos, or --enable-eigen");
+
   // Skip this example if we do not meet certain requirements
 #ifndef LIBMESH_HAVE_VTK
   libmesh_example_requires(false, "--enable-vtk");

examples/fem_system/fem_system_ex3/fem_system_ex3.C

@@ -60,6 +60,10 @@ int main (int argc, char ** argv)
   // Initialize libMesh.
   LibMeshInit init (argc, argv);
 
+  // This example requires a linear solver package.
+  libmesh_example_requires(libMesh::default_solver_package() != INVALID_SOLVER_PACKAGE,
+                           "--enable-petsc, --enable-trilinos, or --enable-eigen");
+
   // Parse the input file
   GetPot infile("fem_system_ex3.in");
 

examples/fem_system/fem_system_ex4/fem_system_ex4.C

@@ -59,6 +59,10 @@ int main (int argc, char ** argv)
   // Initialize libMesh.
   LibMeshInit init (argc, argv);
 
+  // This example requires a linear solver package.
+  libmesh_example_requires(libMesh::default_solver_package() != INVALID_SOLVER_PACKAGE,
+                           "--enable-petsc, --enable-trilinos, or --enable-eigen");
+
 #ifndef LIBMESH_ENABLE_AMR
   libmesh_example_requires(false, "--enable-amr");
 #else

examples/introduction/introduction_ex2/introduction_ex2.C

@@ -71,6 +71,10 @@ int main (int argc, char ** argv)
   // Skip this 2D example if libMesh was compiled as 1D-only.
   libmesh_example_requires(2 <= LIBMESH_DIM, "2D support");
 
+  // This example requires a linear solver package.
+  libmesh_example_requires(libMesh::default_solver_package() != INVALID_SOLVER_PACKAGE,
+                           "--enable-petsc, --enable-trilinos, or --enable-eigen");
+
   // A brief message to the user to inform her of the
   // exact name of the program being run, and its command line.
   libMesh::out << "Running " << argv[0];

examples/introduction/introduction_ex3/introduction_ex3.C

@@ -81,6 +81,10 @@ int main (int argc, char ** argv)
   // Initialize libraries, like in example 2.
   LibMeshInit init (argc, argv);
 
+  // This example requires a linear solver package.
+  libmesh_example_requires(libMesh::default_solver_package() != INVALID_SOLVER_PACKAGE,
+                           "--enable-petsc, --enable-trilinos, or --enable-eigen");
+
   // Brief message to the user regarding the program name
   // and command line arguments.
   libMesh::out << "Running " << argv[0];

examples/introduction/introduction_ex4/introduction_ex4.C

@@ -118,6 +118,10 @@ int main (int argc, char ** argv)
   // Initialize libMesh and any dependent libaries, like in example 2.
   LibMeshInit init (argc, argv);
 
+  // This example requires a linear solver package.
+  libmesh_example_requires(libMesh::default_solver_package() != INVALID_SOLVER_PACKAGE,
+                           "--enable-petsc, --enable-trilinos, or --enable-eigen");
+
   // Declare a performance log for the main program
   // PerfLog perf_main("Main Program");
 

examples/introduction/introduction_ex5/introduction_ex5.C

@@ -100,6 +100,10 @@ int main (int argc, char ** argv)
   // Initialize libMesh and any dependent libaries, like in example 2.
   LibMeshInit init (argc, argv);
 
+  // This example requires a linear solver package.
+  libmesh_example_requires(libMesh::default_solver_package() != INVALID_SOLVER_PACKAGE,
+                           "--enable-petsc, --enable-trilinos, or --enable-eigen");
+
   // Check for proper usage.  The quadrature rule
   // must be given at run time.
   if (argc < 3)

examples/miscellaneous/miscellaneous_ex10/miscellaneous_ex10.C

@@ -73,6 +73,10 @@ int main (int argc, char ** argv)
   START_LOG("Initialize and create cubes", "main");
   LibMeshInit init (argc, argv);
 
+  // This example requires a linear solver package.
+  libmesh_example_requires(libMesh::default_solver_package() != INVALID_SOLVER_PACKAGE,
+                           "--enable-petsc, --enable-trilinos, or --enable-eigen");
+
   // Create a GetPot object to parse the command line
   GetPot command_line (argc, argv);
 

examples/miscellaneous/miscellaneous_ex11/miscellaneous_ex11.C

@@ -79,6 +79,10 @@ int main (int argc, char ** argv)
   // Initialize libMesh.
   LibMeshInit init (argc, argv);
 
+  // This example requires a linear solver package.
+  libmesh_example_requires(libMesh::default_solver_package() != INVALID_SOLVER_PACKAGE,
+                           "--enable-petsc, --enable-trilinos, or --enable-eigen");
+
   // Skip this 3D example if libMesh was compiled as 1D/2D-only.
   libmesh_example_requires (3 == LIBMESH_DIM, "3D support");
 

examples/miscellaneous/miscellaneous_ex5/miscellaneous_ex5.C

@@ -500,6 +500,10 @@ int main (int argc, char** argv)
 {
   LibMeshInit init(argc, argv);
 
+  // This example requires a linear solver package.
+  libmesh_example_requires(libMesh::default_solver_package() != INVALID_SOLVER_PACKAGE,
+                           "--enable-petsc, --enable-trilinos, or --enable-eigen");
+
   // Skip adaptive examples on a non-adaptive libMesh build
 #ifndef LIBMESH_ENABLE_AMR
   libmesh_example_requires(false, "--enable-amr");

examples/reduced_basis/reduced_basis_ex1/reduced_basis_ex1.C

@@ -78,6 +78,10 @@ int main (int argc, char ** argv)
   // Initialize libMesh.
   LibMeshInit init (argc, argv);
 
+  // This example requires a linear solver package.
+  libmesh_example_requires(libMesh::default_solver_package() != INVALID_SOLVER_PACKAGE,
+                           "--enable-petsc, --enable-trilinos, or --enable-eigen");
+
 #if !defined(LIBMESH_HAVE_XDR)
   // We need XDR support to write out reduced bases
   libmesh_example_requires(false, "--enable-xdr");

examples/reduced_basis/reduced_basis_ex4/reduced_basis_ex4.C

@@ -59,6 +59,10 @@ int main (int argc, char ** argv)
   // Initialize libMesh.
   LibMeshInit init (argc, argv);
 
+  // This example requires a linear solver package.
+  libmesh_example_requires(libMesh::default_solver_package() != INVALID_SOLVER_PACKAGE,
+                           "--enable-petsc, --enable-trilinos, or --enable-eigen");
+
 #if !defined(LIBMESH_HAVE_XDR)
   // We need XDR support to write out reduced bases
   libmesh_example_requires(false, "--enable-xdr");

examples/reduced_basis/reduced_basis_ex5/reduced_basis_ex5.C

@@ -84,6 +84,10 @@ int main(int argc, char ** argv)
   // Initialize libMesh.
   LibMeshInit init (argc, argv);
 
+  // This example requires a linear solver package.
+  libmesh_example_requires(libMesh::default_solver_package() != INVALID_SOLVER_PACKAGE,
+                           "--enable-petsc, --enable-trilinos, or --enable-eigen");
+
 #if !defined(LIBMESH_HAVE_XDR)
   // We need XDR support to write out reduced bases
   libmesh_example_requires(false, "--enable-xdr");

examples/reduced_basis/reduced_basis_ex6/reduced_basis_ex6.C

@@ -112,6 +112,10 @@ int main (int argc, char ** argv)
   // Initialize libMesh.
   LibMeshInit init (argc, argv);
 
+  // This example requires a linear solver package.
+  libmesh_example_requires(libMesh::default_solver_package() != INVALID_SOLVER_PACKAGE,
+                           "--enable-petsc, --enable-trilinos, or --enable-eigen");
+
 #if !defined(LIBMESH_HAVE_XDR)
   // We need XDR support to write out reduced bases
   libmesh_example_requires(false, "--enable-xdr");

examples/subdomains/subdomains_ex2/subdomains_ex2.C

@@ -93,6 +93,10 @@ int main (int argc, char ** argv)
   // Initialize libMesh and any dependent libaries, like in example 2.
   LibMeshInit init (argc, argv);
 
+  // This example requires a linear solver package.
+  libmesh_example_requires(libMesh::default_solver_package() != INVALID_SOLVER_PACKAGE,
+                           "--enable-petsc, --enable-trilinos, or --enable-eigen");
+
   // Declare a performance log for the main program
   // PerfLog perf_main("Main Program");
 

examples/systems_of_equations/systems_of_equations_ex1/systems_of_equations_ex1.C

@@ -69,6 +69,10 @@ int main (int argc, char ** argv)
   // Initialize libMesh.
   LibMeshInit init (argc, argv);
 
+  // This example requires a linear solver package.
+  libmesh_example_requires(libMesh::default_solver_package() != INVALID_SOLVER_PACKAGE,
+                           "--enable-petsc, --enable-trilinos, or --enable-eigen");
+
   // Skip this 2D example if libMesh was compiled as 1D-only.
   libmesh_example_requires(2 <= LIBMESH_DIM, "2D support");
 

examples/systems_of_equations/systems_of_equations_ex2/systems_of_equations_ex2.C

@@ -93,6 +93,10 @@ int main (int argc, char** argv)
   // Initialize libMesh.
   LibMeshInit init (argc, argv);
 
+  // This example requires a linear solver package.
+  libmesh_example_requires(libMesh::default_solver_package() != INVALID_SOLVER_PACKAGE,
+                           "--enable-petsc, --enable-trilinos, or --enable-eigen");
+
   // Skip this 2D example if libMesh was compiled as 1D-only.
   libmesh_example_requires(2 <= LIBMESH_DIM, "2D support");
 

examples/systems_of_equations/systems_of_equations_ex3/systems_of_equations_ex3.C

@@ -81,6 +81,10 @@ int main (int argc, char ** argv)
   // Initialize libMesh.
   LibMeshInit init (argc, argv);
 
+  // This example requires a linear solver package.
+  libmesh_example_requires(libMesh::default_solver_package() != INVALID_SOLVER_PACKAGE,
+                           "--enable-petsc, --enable-trilinos, or --enable-eigen");
+
   // Skip this 2D example if libMesh was compiled as 1D-only.
   libmesh_example_requires(2 <= LIBMESH_DIM, "2D support");
 

examples/systems_of_equations/systems_of_equations_ex4/systems_of_equations_ex4.C

@@ -77,6 +77,10 @@ int main (int argc, char ** argv)
   // Initialize libMesh and any dependent libaries
   LibMeshInit init (argc, argv);
 
+  // This example requires a linear solver package.
+  libmesh_example_requires(libMesh::default_solver_package() != INVALID_SOLVER_PACKAGE,
+                           "--enable-petsc, --enable-trilinos, or --enable-eigen");
+
   // Initialize the cantilever mesh
   const unsigned int dim = 2;
 

examples/systems_of_equations/systems_of_equations_ex5/systems_of_equations_ex5.C

@@ -81,6 +81,10 @@ int main (int argc, char ** argv)
   // Initialize libMesh and any dependent libaries
   LibMeshInit init (argc, argv);
 
+  // This example requires a linear solver package.
+  libmesh_example_requires(libMesh::default_solver_package() != INVALID_SOLVER_PACKAGE,
+                           "--enable-petsc, --enable-trilinos, or --enable-eigen");
+
   // This example NaNs with the Eigen sparse linear solvers
   libmesh_example_requires(libMesh::default_solver_package() != EIGEN_SOLVERS, "--enable-petsc or --enable-laspack");
 

examples/systems_of_equations/systems_of_equations_ex6/systems_of_equations_ex6.C

@@ -430,6 +430,10 @@ int main (int argc, char ** argv)
   // Initialize libMesh and any dependent libraries
   LibMeshInit init (argc, argv);
 
+  // This example requires a linear solver package.
+  libmesh_example_requires(libMesh::default_solver_package() != INVALID_SOLVER_PACKAGE,
+                           "--enable-petsc, --enable-trilinos, or --enable-eigen");
+
   // Initialize the cantilever mesh
   const unsigned int dim = 3;
 

examples/transient/transient_ex1/transient_ex1.C

@@ -105,6 +105,10 @@ int main (int argc, char ** argv)
   // Initialize libMesh.
   LibMeshInit init (argc, argv);
 
+  // This example requires a linear solver package.
+  libmesh_example_requires(libMesh::default_solver_package() != INVALID_SOLVER_PACKAGE,
+                           "--enable-petsc, --enable-trilinos, or --enable-eigen");
+
   // This example requires Adaptive Mesh Refinement support - although
   // it only refines uniformly, the refinement code used is the same
   // underneath

examples/transient/transient_ex2/transient_ex2.C

@@ -101,6 +101,10 @@ int main (int argc, char** argv)
   // Initialize libraries, like in example 2.
   LibMeshInit init (argc, argv);
 
+  // This example requires a linear solver package.
+  libmesh_example_requires(libMesh::default_solver_package() != INVALID_SOLVER_PACKAGE,
+                           "--enable-petsc, --enable-trilinos, or --enable-eigen");
+
   // Check for proper usage.
   if (argc < 2)
     libmesh_error_msg("Usage: " << argv[0] << " [meshfile]");

examples/vector_fe/vector_fe_ex1/vector_fe_ex1.C

@@ -80,6 +80,10 @@ int main (int argc, char ** argv)
   // Initialize libraries.
   LibMeshInit init (argc, argv);
 
+  // This example requires a linear solver package.
+  libmesh_example_requires(libMesh::default_solver_package() != INVALID_SOLVER_PACKAGE,
+                           "--enable-petsc, --enable-trilinos, or --enable-eigen");
+
   // Brief message to the user regarding the program name
   // and command line arguments.
   libMesh::out << "Running " << argv[0];

examples/vector_fe/vector_fe_ex2/vector_fe_ex2.C

@@ -49,6 +49,10 @@ int main (int argc, char** argv)
   // Initialize libMesh.
   LibMeshInit init (argc, argv);
 
+  // This example requires a linear solver package.
+  libmesh_example_requires(libMesh::default_solver_package() != INVALID_SOLVER_PACKAGE,
+                           "--enable-petsc, --enable-trilinos, or --enable-eigen");
+
   // Parse the input file
   GetPot infile("vector_fe_ex2.in");
 

examples/vector_fe/vector_fe_ex3/vector_fe_ex3.C

@@ -49,6 +49,10 @@ int main (int argc, char ** argv)
   // Initialize libMesh.
   LibMeshInit init (argc, argv);
 
+  // This example requires a linear solver package.
+  libmesh_example_requires(libMesh::default_solver_package() != INVALID_SOLVER_PACKAGE,
+                           "--enable-petsc, --enable-trilinos, or --enable-eigen");
+
   // Parse the input file
   GetPot infile("vector_fe_ex3.in");
 

examples/vector_fe/vector_fe_ex4/vector_fe_ex4.C

@@ -49,6 +49,10 @@ int main (int argc, char ** argv)
   // Initialize libMesh.
   LibMeshInit init (argc, argv);
 
+  // This example requires a linear solver package.
+  libmesh_example_requires(libMesh::default_solver_package() != INVALID_SOLVER_PACKAGE,
+                           "--enable-petsc, --enable-trilinos, or --enable-eigen");
+
   // Parse the input file
   GetPot infile("vector_fe_ex4.in");