1: #include <petsc/private/petscimpl.h>

  3: static PetscInt petsc_checkpointer_intensity = 1;

  5: /*@
  6:   PetscCheckPointerSetIntensity - Set the intensity of debug pointer checks

  8:   Not Collective

 10:   Input Parameter:
 11: . intensity - how much to check pointers for validity

 13:   Options Database Key:
 14: . -check_pointer_intensity - intensity (0, 1, or 2)

 16:   Level: advanced

 18:   Notes:
 19:   An intense pointer check registers a signal handler and attempts to dereference to confirm
 20:   whether the address is valid.  An intensity of 0 never uses signal handlers, 1 uses them when
 21:   not in a "hot" function, and intensity of 2 always uses a signal handler.

 23: .seealso: `PetscCheckPointer()`, `PetscFunctionBeginHot()`
 24: @*/
 25: PetscErrorCode PetscCheckPointerSetIntensity(PetscInt intensity)
 26: {
 27:   PetscFunctionBegin;
 28:   PetscCheck((intensity >= 0) && (intensity <= 2), PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Intensity %" PetscInt_FMT " not in [0,2]", intensity);
 29:   petsc_checkpointer_intensity = intensity;
 30:   PetscFunctionReturn(PETSC_SUCCESS);
 31: }

 33: #if PetscDefined(HAVE_SETJMP_H)
 34:   #include <setjmp.h>
 35: static jmp_buf   PetscSegvJumpBuf;
 36: static PetscBool PetscSegvJumpBuf_set;

 38: /*@C
 39:   PetscSignalSegvCheckPointerOrMpi - To be called from a signal handler for SIGSEGV.

 41:   Not Collective, No Fortran Support

 43:   Level: developer

 45:   Note:
 46:   If the signal was received while executing `PetscCheckPointer()`, this function longjmps back
 47:   there, otherwise it returns with no effect. This function is called automatically by
 48:   `PetscSignalHandlerDefault()`.

 50: .seealso: `PetscPushSignalHandler()`
 51: @*/
 52: void PetscSignalSegvCheckPointerOrMpi(void)
 53: {
 54:   if (PetscSegvJumpBuf_set) longjmp(PetscSegvJumpBuf, 1);
 55: }

 57: /*@C
 58:   PetscCheckPointer - Returns `PETSC_TRUE` if a pointer points to accessible data

 60:   Not Collective, No Fortran Support

 62:   Input Parameters:
 63: + ptr   - the pointer
 64: - dtype - the type of data the pointer is suppose to point to

 66:   Level: developer

 68:   Notes:
 69:   This is a non-standard PETSc function in that it returns the result and does not return an error code.

 71:   This function always returns true when running under Valgrind, or when compiled with asan options.

 73: .seealso: `PetscCheckPointerSetIntensity()`
 74: @*/
 75: PetscBool PetscCheckPointer(const void *ptr, PetscDataType dtype)
 76: {
 77:   if (PETSC_RUNNING_ON_VALGRIND) return PETSC_TRUE;
 78:   if (!ptr) return PETSC_FALSE;
 79:   if (petsc_checkpointer_intensity < 1) return PETSC_TRUE;
 80:   if (PetscDefined(HAVE_SANITIZER)) return PETSC_TRUE;

 82:   #if PetscDefined(USE_DEBUG) && !PetscDefined(HAVE_THREADSAFETY)
 83:   /* Skip the verbose check if we are inside a hot function. */
 84:   if (petscstack.hotdepth > 0 && petsc_checkpointer_intensity < 2) return PETSC_TRUE;
 85:   #endif

 87:   PetscSegvJumpBuf_set = PETSC_TRUE;

 89:   if (setjmp(PetscSegvJumpBuf)) {
 90:     /* A segv was triggered in the code below hence we return with an error code */
 91:     PetscSegvJumpBuf_set = PETSC_FALSE;
 92:     return PETSC_FALSE;
 93:   } else {
 94:     switch (dtype) {
 95:     case PETSC_INT: {
 96:       PETSC_UNUSED PetscInt x = *(volatile PetscInt *)ptr;
 97:       break;
 98:     }
 99:   #if defined(PETSC_USE_COMPLEX)
100:     case PETSC_SCALAR: { /* C++ is seriously dysfunctional with volatile std::complex. */
101:     #if defined(PETSC_USE_CXXCOMPLEX)
102:       PetscReal                         xreal = ((volatile PetscReal *)ptr)[0], ximag = ((volatile PetscReal *)ptr)[1];
103:       PETSC_UNUSED volatile PetscScalar x = xreal + PETSC_i * ximag;
104:     #else
105:       PETSC_UNUSED PetscScalar x = *(volatile PetscScalar *)ptr;
106:     #endif
107:       break;
108:     }
109:   #endif
110:     case PETSC_REAL: {
111:       PETSC_UNUSED PetscReal x = *(volatile PetscReal *)ptr;
112:       break;
113:     }
114:     case PETSC_BOOL: {
115:       PETSC_UNUSED PetscBool x = *(volatile PetscBool *)ptr;
116:       break;
117:     }
118:     case PETSC_ENUM: {
119:       PETSC_UNUSED PetscEnum x = *(volatile PetscEnum *)ptr;
120:       break;
121:     }
122:     case PETSC_CHAR: {
123:       PETSC_UNUSED char x = *(volatile char *)ptr;
124:       break;
125:     }
126:     case PETSC_OBJECT: {
127:       PETSC_UNUSED volatile PetscClassId classid = ((PetscObject)ptr)->classid;
128:       break;
129:     }
130:     default:;
131:     }
132:   }
133:   PetscSegvJumpBuf_set = PETSC_FALSE;
134:   return PETSC_TRUE;
135: }
136: #endif