5 files changed, 27 insertions, 19 deletions
diff --git a/src/H5FDsubfiling/H5FDioc.c b/src/H5FDsubfiling/H5FDioc.c
index 39766de..80771c0 100644
--- a/src/H5FDsubfiling/H5FDioc.c
+++ b/src/H5FDsubfiling/H5FDioc.c
@@ -32,8 +32,6 @@
 #include "H5MMprivate.h"  /* Memory management        */
 #include "H5Pprivate.h"   /* Property lists           */
 
-#define CANBE_UNUSED(X) (void)(X)
-
 /* The driver identification number, initialized at runtime */
 static hid_t H5FD_IOC_g = H5I_INVALID_HID;
 
@@ -1219,13 +1217,14 @@ static herr_t
 H5FD__ioc_read(H5FD_t *_file, H5FD_mem_t H5_ATTR_UNUSED type, hid_t H5_ATTR_UNUSED dxpl_id, haddr_t addr,
                size_t size, void *buf)
 {
-    H5FD_ioc_t *file      = (H5FD_ioc_t *)_file;
-    herr_t      ret_value = SUCCEED;
+#ifndef NDEBUG
+    H5FD_ioc_t *file = (H5FD_ioc_t *)_file;
+#endif
+    herr_t ret_value = SUCCEED;
 
     H5FD_IOC_LOG_CALL(__func__);
 
     assert(file && file->pub.cls);
-    CANBE_UNUSED(file);
     assert(buf);
 
     /* Check for overflow conditions */
diff --git a/src/H5FDsubfiling/H5FDioc_int.c b/src/H5FDsubfiling/H5FDioc_int.c
index 674b08d..5528fc8 100644
--- a/src/H5FDsubfiling/H5FDioc_int.c
+++ b/src/H5FDsubfiling/H5FDioc_int.c
@@ -423,8 +423,14 @@ ioc__async_completion(MPI_Request *mpi_reqs, size_t num_reqs)
     assert(mpi_reqs);
 
     H5_CHECK_OVERFLOW(num_reqs, size_t, int);
+
+    /* Have to supppress gcc warnings regarding MPI_STATUSES_IGNORE
+     * with MPICH (https://github.com/pmodels/mpich/issues/5687)
+     */
+    H5_GCC_DIAG_OFF("stringop-overflow")
     if (MPI_SUCCESS != (mpi_code = MPI_Waitall((int)num_reqs, mpi_reqs, MPI_STATUSES_IGNORE)))
         H5_SUBFILING_MPI_GOTO_ERROR(FAIL, "MPI_Waitall failed", mpi_code);
+    H5_GCC_DIAG_ON("stringop-overflow")
 
 done:
     H5_SUBFILING_FUNC_LEAVE;
diff --git a/src/H5FDsubfiling/H5FDsubfile_int.c b/src/H5FDsubfiling/H5FDsubfile_int.c
index cb210b6..a7dd864 100644
--- a/src/H5FDsubfiling/H5FDsubfile_int.c
+++ b/src/H5FDsubfiling/H5FDsubfile_int.c
@@ -143,17 +143,19 @@ H5FD__subfiling__truncate_sub_files(hid_t context_id, int64_t logical_file_eof,
         }
 
         /* Wait for truncate operations to complete */
+        H5_GCC_DIAG_OFF("stringop-overflow")
         if (MPI_SUCCESS != (mpi_code = MPI_Waitall(num_subfiles_owned, recv_reqs, MPI_STATUSES_IGNORE)))
             H5_SUBFILING_MPI_GOTO_ERROR(FAIL, "MPI_Waitall", mpi_code);
-
-            /* sanity check -- compute the file eof using the same mechanism used to
-             * compute the subfile eof.  Assert that the computed value and the
-             * actual value match.
-             *
-             * Do this only for debug builds -- probably delete this before release.
-             *
-             *                                           JRM -- 12/15/21
-             */
+        H5_GCC_DIAG_ON("stringop-overflow")
+
+        /* sanity check -- compute the file eof using the same mechanism used to
+         * compute the subfile eof.  Assert that the computed value and the
+         * actual value match.
+         *
+         * Do this only for debug builds -- probably delete this before release.
+         *
+         *                                           JRM -- 12/15/21
+         */
 
 #ifndef NDEBUG
         {
@@ -339,15 +341,18 @@ H5FD__subfiling__get_real_eof(hid_t context_id, int64_t *logical_eof_ptr)
     }
 
     /* Wait for EOF communication to complete */
+    H5_GCC_DIAG_OFF("stringop-overflow")
     if (MPI_SUCCESS != (mpi_code = MPI_Waitall(num_subfiles, recv_reqs, MPI_STATUSES_IGNORE)))
         H5_SUBFILING_MPI_GOTO_ERROR(FAIL, "MPI_Waitall", mpi_code);
+    H5_GCC_DIAG_ON("stringop-overflow")
 
     for (int i = 0; i < num_subfiles; i++) {
+#ifndef NDEBUG
         int ioc_rank = (int)recv_msg[3 * i];
+#endif
 
         assert(ioc_rank >= 0);
         assert(ioc_rank < n_io_concentrators);
-        CANBE_UNUSED(ioc_rank);
         assert(sf_eofs[i] == -1);
 
         sf_eofs[i] = recv_msg[(3 * i) + 1];
diff --git a/src/H5FDsubfiling/H5FDsubfiling.c b/src/H5FDsubfiling/H5FDsubfiling.c
index d8616c8..a2daba0 100644
--- a/src/H5FDsubfiling/H5FDsubfiling.c
+++ b/src/H5FDsubfiling/H5FDsubfiling.c
@@ -1556,7 +1556,7 @@ H5FD__subfiling_read(H5FD_t *_file, H5FD_mem_t type, hid_t H5_ATTR_UNUSED dxpl_i
         H5_SUBFILING_GOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "addr undefined, addr = %" PRIuHADDR, addr);
     if (REGION_OVERFLOW(addr, size))
         H5_SUBFILING_GOTO_ERROR(H5E_ARGS, H5E_OVERFLOW, FAIL,
-                                "addr overflow, addr = %" PRIuHADDR ", size = %" PRIuHADDR, addr, size);
+                                "addr overflow, addr = %" PRIuHADDR ", size = %zu", addr, size);
 
     /* Temporarily reject collective I/O until support is implemented (unless types are simple MPI_BYTE) */
     {
@@ -1789,7 +1789,7 @@ H5FD__subfiling_write(H5FD_t *_file, H5FD_mem_t type, hid_t H5_ATTR_UNUSED dxpl_
         H5_SUBFILING_GOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "addr undefined, addr = %" PRIuHADDR, addr);
     if (REGION_OVERFLOW(addr, size))
         H5_SUBFILING_GOTO_ERROR(H5E_ARGS, H5E_OVERFLOW, FAIL,
-                                "addr overflow, addr = %" PRIuHADDR ", size = %" PRIuHADDR, addr, size);
+                                "addr overflow, addr = %" PRIuHADDR ", size = %zu", addr, size);
 
     /* Temporarily reject collective I/O until support is implemented (unless types are simple MPI_BYTE) */
     {
diff --git a/src/H5FDsubfiling/H5FDsubfiling_priv.h b/src/H5FDsubfiling/H5FDsubfiling_priv.h
index 9cc32f1..08fef7d 100644
--- a/src/H5FDsubfiling/H5FDsubfiling_priv.h
+++ b/src/H5FDsubfiling/H5FDsubfiling_priv.h
@@ -63,6 +63,4 @@ H5_DLL herr_t H5FD__subfiling__get_real_eof(hid_t context_id, int64_t *logical_e
 }
 #endif
 
-#define CANBE_UNUSED(X) (void)(X)
-
 #endif /* H5FDsubfiling_priv_H */