Added a free wrapper that lets us free constant pointers without

generating warnings.

Also, brought the const-ness of the VOL connector info in line with
the VFD info (not visible externally).

8 files changed, 62 insertions, 25 deletions

diff --git a/src/H5CX.c b/src/H5CX.c
index 160aa84..244439e 100644
--- a/src/H5CX.c
+++ b/src/H5CX.c
@@ -1034,6 +1034,7 @@ H5CX_restore_state(const H5CX_state_t *api_state)
  *
  *-------------------------------------------------------------------------
  */
+H5_GCC_DIAG_OFF(cast-qual)
 herr_t
 H5CX_free_state(H5CX_state_t *api_state)
 {
@@ -1071,9 +1072,9 @@ H5CX_free_state(H5CX_state_t *api_state)
 
     /* Release the VOL connector property, if it was set */
     if(api_state->vol_connector_prop.connector_id) {
-        /* Clean up any VOL connector info */
+        /* Clean up any VOL connector info, ignoring const-ness of connector info */
         if(api_state->vol_connector_prop.connector_info)
-            if(H5VL_free_connector_info(api_state->vol_connector_prop.connector_id, api_state->vol_connector_prop.connector_info) < 0)
+            if(H5VL_free_connector_info(api_state->vol_connector_prop.connector_id, (void *)api_state->vol_connector_prop.connector_info) < 0)
                 HGOTO_ERROR(H5E_CONTEXT, H5E_CANTRELEASE, FAIL, "unable to release VOL connector info object")
         /* Decrement connector ID */
         if(H5I_dec_ref(api_state->vol_connector_prop.connector_id) < 0)
@@ -1086,6 +1087,7 @@ H5CX_free_state(H5CX_state_t *api_state)
 done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5CX_free_state() */
+H5_GCC_DIAG_ON(cast-qual)
 
 
 /*-------------------------------------------------------------------------
diff --git a/src/H5Eint.c b/src/H5Eint.c
index e76db82..acd5b28 100644
--- a/src/H5Eint.c
+++ b/src/H5Eint.c
@@ -883,12 +883,12 @@ H5E__clear_entries(H5E_t *estack, size_t nentries)
 
         /* Release strings */
         if(error->func_name)
-            error->func_name = (const char *) H5MM_xfree((void *)error->func_name);        /* Casting away const OK - QAK */
+            error->func_name = (const char *) H5MM_xfree_const(error->func_name);
         if(error->file_name)
-            error->file_name = (const char *) H5MM_xfree((void *)error->file_name);        /* Casting away const OK - QAK */
+            error->file_name = (const char *) H5MM_xfree_const(error->file_name);
         if(error->desc)
-            error->desc = (const char *) H5MM_xfree((void *)error->desc);     /* Casting away const OK - QAK */
-    } /* end for */
+            error->desc = (const char *) H5MM_xfree_const(error->desc);
+    }
 
     /* Decrement number of errors on stack */
     estack->nused -= u;
diff --git a/src/H5FD.c b/src/H5FD.c
index 1a4ab4d..0cc5654 100644
--- a/src/H5FD.c
+++ b/src/H5FD.c
@@ -574,6 +574,7 @@ done:
  *
  *-------------------------------------------------------------------------
  */
+H5_GCC_DIAG_OFF(cast-qual)
 herr_t
 H5FD_fapl_close(hid_t driver_id, const void *driver_info)
 {
@@ -591,17 +592,19 @@ H5FD_fapl_close(hid_t driver_id, const void *driver_info)
         /* Allow driver to free info or do it ourselves */
         if(driver_info) {
             if(driver->fapl_free) {
-                if((driver->fapl_free)((void *)driver_info) < 0)        /* Casting away const OK -QAK */
+                /* Free the const pointer (why we turn off the diagnostic) */
+                if((driver->fapl_free)((void *)driver_info) < 0)
                     HGOTO_ERROR(H5E_VFL, H5E_CANTFREE, FAIL, "driver free request failed")
-            } /* end if */
+            }
             else
-                driver_info = H5MM_xfree((void *)driver_info);        /* Casting away const OK -QAK */
-        } /* end if */
-    } /* end if */
+                driver_info = H5MM_xfree_const(driver_info);
+        }
+    }
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5FD_fapl_close() */
+H5_GCC_DIAG_ON(cast-qual)
 
 
 /*-------------------------------------------------------------------------
diff --git a/src/H5MM.c b/src/H5MM.c
index ac3c26e..dae3f81 100644
--- a/src/H5MM.c
+++ b/src/H5MM.c
@@ -566,6 +566,32 @@ H5MM_xfree(void *mem)
 
 
 /*-------------------------------------------------------------------------
+ * Function:    H5MM_xfree_const
+ *
+ * Purpose:     H5MM_xfree() wrapper that handles const pointers without
+ *              warnings. Used for freeing buffers that should be regarded
+ *              as const in use but need to be freed when no longer needed.
+ *
+ * Return:      Success:    NULL
+ *              Failure:    never fails
+ *
+ *-------------------------------------------------------------------------
+ */
+H5_GCC_DIAG_OFF(cast-qual)
+void *
+H5MM_xfree_const(const void *mem)
+{
+    /* Use FUNC_ENTER_NOAPI_NOINIT_NOERR here to avoid performance issues */
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+
+    H5MM_xfree((void *)mem);
+
+    FUNC_LEAVE_NOAPI(NULL)
+} /* end H5MM_xfree_const() */
+H5_GCC_DIAG_ON(cast-qual)
+
+
+/*-------------------------------------------------------------------------
  * Function:    H5MM_memcpy
  *
  * Purpose:     Like memcpy(3) but with sanity checks on the parameters,
diff --git a/src/H5MMprivate.h b/src/H5MMprivate.h
index 2053215..240b931 100644
--- a/src/H5MMprivate.h
+++ b/src/H5MMprivate.h
@@ -45,6 +45,7 @@ H5_DLL void *H5MM_realloc(void *mem, size_t size);
 H5_DLL char *H5MM_xstrdup(const char *s);
 H5_DLL char *H5MM_strdup(const char *s);
 H5_DLL void *H5MM_xfree(void *mem);
+H5_DLL void *H5MM_xfree_const(const void *mem);
 H5_DLL void *H5MM_memcpy(void *dest, const void *src, size_t n);
 #if defined H5_MEMORY_ALLOC_SANITY_CHECK
 H5_DLL void H5MM_sanity_check_all(void);
diff --git a/src/H5Pfapl.c b/src/H5Pfapl.c
index 3668229..f238466 100644
--- a/src/H5Pfapl.c
+++ b/src/H5Pfapl.c
@@ -1146,6 +1146,7 @@ done:
  *
  *-------------------------------------------------------------------------
  */
+H5_GCC_DIAG_OFF(cast-qual)
 static herr_t
 H5P__file_driver_free(void *value)
 {
@@ -1167,22 +1168,24 @@ H5P__file_driver_free(void *value)
 
                 /* Allow driver to free info or do it ourselves */
                 if(driver->fapl_free) {
-                    if((driver->fapl_free)((void *)info->driver_info) < 0)      /* Casting away const OK -QAK */
+                    /* Free the const pointer (why we turn off the diagnostic) */
+                    if((driver->fapl_free)((void *)info->driver_info) < 0)
                         HGOTO_ERROR(H5E_PLIST, H5E_CANTFREE, FAIL, "driver info free request failed")
-                } /* end if */
+                }
                 else
-                    H5MM_xfree((void *)info->driver_info);      /* Casting away const OK -QAK */
-            } /* end if */
+                    H5MM_xfree_const(info->driver_info);
+            }
 
             /* Decrement reference count for driver */
             if(H5I_dec_ref(info->driver_id) < 0)
                 HGOTO_ERROR(H5E_PLIST, H5E_CANTDEC, FAIL, "can't decrement reference count for driver ID")
-        } /* end if */
-    } /* end if */
+        }
+    }
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5P__file_driver_free() */
+H5_GCC_DIAG_ON(cast-qual)
 
 
 /*-------------------------------------------------------------------------
@@ -5407,7 +5410,7 @@ H5P_set_vol(H5P_genplist_t *plist, hid_t vol_id, const void *vol_info)
 
         /* Prepare the VOL connector property */
         vol_prop.connector_id = vol_id;
-        vol_prop.connector_info = (void *)vol_info;
+        vol_prop.connector_info = vol_info;
 
         /* Set the connector ID & info property */
         if(H5P_set(plist, H5F_ACS_VOL_CONN_NAME, &vol_prop) < 0)
diff --git a/src/H5VLint.c b/src/H5VLint.c
index 39b0f53..df1f7a4 100644
--- a/src/H5VLint.c
+++ b/src/H5VLint.c
@@ -318,7 +318,7 @@ H5VL__free_cls(H5VL_class_t *cls)
         HGOTO_ERROR(H5E_VOL, H5E_CANTCLOSEOBJ, FAIL, "VOL connector did not terminate cleanly")
 
     /* Release the class */
-    H5MM_xfree((void *)cls->name);      /* Casting away const OK -QAK */
+    H5MM_xfree_const(cls->name);
     H5FL_FREE(H5VL_class_t, cls);
 
 done:
@@ -670,6 +670,7 @@ done:
  *
  *-------------------------------------------------------------------------
  */
+H5_GCC_DIAG_OFF(cast-qual)
 herr_t
 H5VL_conn_free(const H5VL_connector_prop_t *connector_prop)
 {
@@ -681,19 +682,20 @@ H5VL_conn_free(const H5VL_connector_prop_t *connector_prop)
         /* Free the connector info (if it exists) and decrement the ID */
         if(connector_prop->connector_id > 0) {
             if(connector_prop->connector_info)
-                /* Free the connector info */
-                if(H5VL_free_connector_info(connector_prop->connector_id, (void *)connector_prop->connector_info) < 0)        /* Casting away const OK - QAK */
+                /* Free the connector info, ignoring the const */
+                if(H5VL_free_connector_info(connector_prop->connector_id, (void *)connector_prop->connector_info) < 0)
                     HGOTO_ERROR(H5E_VOL, H5E_CANTRELEASE, FAIL, "unable to release VOL connector info object")
 
             /* Decrement reference count for connector ID */
             if(H5I_dec_ref(connector_prop->connector_id) < 0)
                 HGOTO_ERROR(H5E_VOL, H5E_CANTDEC, FAIL, "can't decrement reference count for connector ID")
-        } /* end if */
-    } /* end if */
+        }
+    }
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5VL_conn_free() */
+H5_GCC_DIAG_ON(cast-qual)
 
 
 /*-------------------------------------------------------------------------
@@ -1144,7 +1146,7 @@ H5VL_register_connector(const void *_cls, hbool_t app_ref, hid_t vipl_id)
 done:
     if(ret_value < 0 && saved) {
         if(saved->name)
-            H5MM_xfree((void *)(saved->name));  /* Casting away const OK -QAK */
+            H5MM_xfree_const(saved->name);
 
         H5FL_FREE(H5VL_class_t, saved);
     } /* end if */
diff --git a/src/H5VLprivate.h b/src/H5VLprivate.h
index 24ae1f3..27dd18c 100644
--- a/src/H5VLprivate.h
+++ b/src/H5VLprivate.h
@@ -44,7 +44,7 @@ typedef struct H5VL_object_t {
 /* Internal structure to hold the connector ID & info for FAPLs */
 typedef struct H5VL_connector_prop_t {
     hid_t       connector_id;           /* VOL connector's ID                                   */
-    void        *connector_info;        /* VOL connector info, for open callbacks               */
+    const void  *connector_info;        /* VOL connector info, for open callbacks               */
 } H5VL_connector_prop_t;
 
 /* Which kind of VOL connector field to use for searching */