Handle PETSc signature change for FormFunctionForColoring

CMakeLists.txt

@@ -523,10 +523,8 @@ if (BOUT_ENABLE_WARNINGS)
    )
 
  include(EnableCXXWarningIfSupport)
- # Note we explicitly turn off -Wcast-function-type as PETSc *requires*
- # we cast a function to the wrong type in MatFDColoringSetFunction
  target_enable_cxx_warning_if_supported(bout++
-   FLAGS -Wnull-dereference -Wno-cast-function-type
+   FLAGS -Wnull-dereference
    )
 endif()
 

src/solver/impls/imex-bdf2/imex-bdf2.cxx

@@ -118,7 +118,25 @@ static PetscErrorCode FormFunctionForColoring(SNES UNUSED(snes), Vec x, Vec f,
   return static_cast<IMEXBDF2*>(ctx)->snes_function(x, f, true);
 }
 
-static PetscErrorCode imexbdf2PCapply(PC pc, Vec x, Vec y) {
+// Global context to store IMEXBDF2 instance
+static void* imexbdf2_ctx = nullptr;
+
+#if PETSC_VERSION_GE(3, 24, 0) || PETSC_VERSION_RELEASE == 0
+// Wrapper for PETSc 3.24 and later (signature: PetscErrorCode (*)(void*, Vec, Vec, void*))
+static PetscErrorCode FormFunctionForColoringWrapper(void*, Vec x, Vec y, void* ctx) {
+  SNES dummy_snes = nullptr;
+  return FormFunctionForColoring(dummy_snes, x, y, ctx);
+}
+#else
+// Wrapper for PETSc < 3.20 (signature: PetscErrorCode (*)(void))
+static PetscErrorCode FormFunctionForColoringWrapper() {
+  SNES dummy_snes = nullptr;
+  Vec dummy_vec = nullptr;
+  return FormFunctionForColoring(dummy_snes, dummy_vec, dummy_vec, imexbdf2_ctx);
+}
+#endif
+
+PetscErrorCode imexbdf2PCapply(PC pc, Vec x, Vec y) {
   int ierr;
 
   // Get the context
@@ -651,9 +669,8 @@ void IMEXBDF2::constructSNES(SNES* snesIn) {
       // Create data structure for SNESComputeJacobianDefaultColor
       MatFDColoringCreate(Jmf, iscoloring, &fdcoloring);
       // Set the function to difference
-      MatFDColoringSetFunction(
-          fdcoloring, reinterpret_cast<PetscErrorCode (*)()>(FormFunctionForColoring),
-          this);
+      imexbdf2_ctx = this;
+      MatFDColoringSetFunction(fdcoloring, FormFunctionForColoringWrapper, this);
       MatFDColoringSetFromOptions(fdcoloring);
       MatFDColoringSetUp(Jmf, iscoloring, fdcoloring);
       ISColoringDestroy(&iscoloring);

src/solver/impls/petsc/petsc.cxx

@@ -61,6 +61,26 @@ extern PetscErrorCode PhysicsPCApply(PC, Vec x, Vec y);
 extern PetscErrorCode PhysicsJacobianApply(Mat J, Vec x, Vec y);
 extern PetscErrorCode PhysicsSNESApply(SNES, Vec);
 
+// Global context to store PetscSolver instance
+static void* petsc_ctx = nullptr;
+
+#if PETSC_VERSION_GE(3, 24, 0) || PETSC_VERSION_RELEASE == 0
+// Wrapper for PETSc 3.24 and later (signature: PetscErrorCode (*)(void*, Vec, Vec, void*))
+static PetscErrorCode FormFunctionForColoringWrapper(void*, Vec x, Vec y, void* ctx) {
+  TS dummy_ts = nullptr;
+  BoutReal dummy_time = 0.0;
+  return solver_f(dummy_ts, dummy_time, x, y, ctx);
+}
+#else
+// Wrapper for PETSc < 3.20 (signature: PetscErrorCode (*)(void))
+static PetscErrorCode FormFunctionForColoringWrapper() {
+  TS dummy_ts = nullptr;
+  BoutReal dummy_time = 0.0;
+  Vec dummy_vec = nullptr;
+  return solver_f(dummy_ts, dummy_time, dummy_vec, dummy_vec, petsc_ctx);
+}
+#endif
+
 PetscSolver::PetscSolver(Options* opts)
     : Solver(opts),
       diagnose(
@@ -514,8 +534,8 @@ int PetscSolver::init() {
   CHKERRQ(ierr);
   ierr = ISColoringDestroy(&iscoloring);
   CHKERRQ(ierr);
-  ierr = MatFDColoringSetFunction(matfdcoloring,
-                                  reinterpret_cast<PetscErrorCode (*)()>(solver_f), this);
+  petsc_ctx = this;
+  ierr = MatFDColoringSetFunction(matfdcoloring, FormFunctionForColoringWrapper, this);
   CHKERRQ(ierr);
   ierr = SNESSetJacobian(snes, J, J, SNESComputeJacobianDefaultColor, matfdcoloring);
   CHKERRQ(ierr);

src/solver/impls/snes/snes.cxx

@@ -86,6 +86,24 @@ static PetscErrorCode FormFunctionForColoring(SNES UNUSED(snes), Vec x, Vec f,
   return static_cast<SNESSolver*>(ctx)->snes_function(x, f, true);
 }
 
+// Global context to store SNESSolver instance
+static void* snes_ctx = nullptr;
+
+#if PETSC_VERSION_GE(3, 24, 0) || PETSC_VERSION_RELEASE == 0
+// Wrapper for PETSc 3.24 and later (signature: PetscErrorCode (*)(void*, Vec, Vec, void*))
+static PetscErrorCode FormFunctionForColoringWrapper(void*, Vec x, Vec y, void* ctx) {
+  SNES dummy_snes = nullptr;
+  return FormFunctionForColoring(dummy_snes, x, y, ctx);
+}
+#else
+// Wrapper for PETSc < 3.20 (signature: PetscErrorCode (*)(void))
+static PetscErrorCode FormFunctionForColoringWrapper() {
+  SNES dummy_snes = nullptr;
+  Vec dummy_vec = nullptr;
+  return FormFunctionForColoring(dummy_snes, dummy_vec, dummy_vec, snes_ctx);
+}
+#endif
+
 static PetscErrorCode snesPCapply(PC pc, Vec x, Vec y) {
   int ierr;
 
@@ -1291,8 +1309,8 @@ void SNESSolver::updateColoring() {
   // Replace the old coloring with the new one
   MatFDColoringDestroy(&fdcoloring);
   MatFDColoringCreate(Jfd, iscoloring, &fdcoloring);
-  MatFDColoringSetFunction(
-      fdcoloring, reinterpret_cast<PetscErrorCode (*)()>(FormFunctionForColoring), this);
+  snes_ctx = this;
+  MatFDColoringSetFunction(fdcoloring, FormFunctionForColoringWrapper, this);
   MatFDColoringSetFromOptions(fdcoloring);
   MatFDColoringSetUp(Jfd, iscoloring, fdcoloring);
   ISColoringDestroy(&iscoloring);