diff --git a/examples/h5_attribute.c b/examples/h5_attribute.c
index 340015102d5..97be7f5bece 100644
--- a/examples/h5_attribute.c
+++ b/examples/h5_attribute.c
@@ -235,7 +235,7 @@ attr_info(hid_t loc_id, const char *name, const H5A_info_t *ainfo, void *opdata)
     float * float_array; /* Pointer to the array attribute. */
 
     /* avoid warnings */
-    opdata = opdata;
+    (void)opdata;
 
     /*
      * Open the attribute using its name.
diff --git a/examples/h5_group.c b/examples/h5_group.c
index 4b489f046cd..40acafece7d 100644
--- a/examples/h5_group.c
+++ b/examples/h5_group.c
@@ -171,9 +171,9 @@ static herr_t
 file_info(hid_t loc_id, const char *name, const H5L_info2_t *linfo, void *opdata)
 {
     /* avoid compiler warnings */
-    loc_id = loc_id;
-    opdata = opdata;
-    linfo  = linfo;
+    (void)loc_id;
+    (void)opdata;
+    (void)linfo;
 
     /*
      * Display group name. The name is passed to the function by
@@ -198,8 +198,8 @@ group_info(hid_t loc_id, const char *name, const H5L_info2_t *linfo, void *opdat
     int         rank_chunk;
 
     /* avoid warnings */
-    opdata = opdata;
-    linfo  = linfo;
+    (void)opdata;
+    (void)linfo;
 
     /*
      * Open the datasets using their names.
diff --git a/hl/src/H5LT.c b/hl/src/H5LT.c
index 6478a96f4cf..33af7d8f00a 100644
--- a/hl/src/H5LT.c
+++ b/hl/src/H5LT.c
@@ -1309,6 +1309,10 @@ find_dataset(H5_ATTR_UNUSED hid_t loc_id, const char *name, H5_ATTR_UNUSED const
     if (name == NULL)
         return ret;
 
+    /* Shut the compiler up */
+    (void)loc_id;
+    (void)linfo;
+
     /* Define a positive value for return value if the dataset was found. This will
      * cause the iterator to immediately return that positive value,
      * indicating short-circuit success
diff --git a/hl/test/test_ds.c b/hl/test/test_ds.c
index 90110a4449a..20e3e826bd4 100644
--- a/hl/test/test_ds.c
+++ b/hl/test/test_ds.c
@@ -3554,9 +3554,9 @@ verify_scale(hid_t dset, unsigned dim, hid_t scale_id, void *visitor_data)
     int ret = 0;
 
     /* unused */
-    dset         = dset;
-    dim          = dim;
-    visitor_data = visitor_data;
+    (void)dset;
+    (void)dim;
+    (void)visitor_data;
 
     /* define a positive value for return value. This will cause the iterator to
     immediately return that positive value, indicating short-circuit success
@@ -3602,8 +3602,8 @@ read_scale(hid_t dset, unsigned dim, hid_t scale_id, void *visitor_data)
     char *   data = (char *)visitor_data;
 
     /* unused */
-    dset = dset;
-    dim  = dim;
+    (void)dset;
+    (void)dim;
 
     /* get space */
     if ((sid = H5Dget_space(scale_id)) < 0)
@@ -3691,7 +3691,7 @@ match_dim_scale(hid_t did, unsigned dim, hid_t dsid, void *visitor_data)
     hsize_t  storage_size;
 
     /* Stop compiler from whining about "unused parameters" */
-    visitor_data = visitor_data;
+    (void)visitor_data;
 
     /*-------------------------------------------------------------------------
      * get DID (dataset) space info
@@ -3766,9 +3766,9 @@ static herr_t
 op_continue(hid_t dset, unsigned dim, hid_t scale_id, void *visitor_data)
 {
     /* Stop compiler from whining about "unused parameters" */
-    dset     = dset;
-    dim      = dim;
-    scale_id = scale_id;
+    (void)dset;
+    (void)dim;
+    (void)scale_id;
 
     if (visitor_data != NULL) {
         (*(int *)visitor_data)++;
@@ -3799,9 +3799,9 @@ static herr_t
 op_stop(hid_t dset, unsigned dim, hid_t scale_id, void *visitor_data)
 {
     /* Stop compiler from whining about "unused parameters" */
-    dset     = dset;
-    dim      = dim;
-    scale_id = scale_id;
+    (void)dset;
+    (void)dim;
+    (void)scale_id;
 
     if (visitor_data != NULL) {
         (*(int *)visitor_data)++;
diff --git a/test/cache.c b/test/cache.c
index 767bae00f6f..06a862737b4 100644
--- a/test/cache.c
+++ b/test/cache.c
@@ -27297,7 +27297,7 @@ check_metadata_blizzard_absence(hbool_t fill_via_insertion, unsigned paged)
 
         /* Fill out the rest of the cache with entries */
         /* Verify expected status of entries after each insertion */
-        for (entry_idx = entry_idx; entry_idx < 50; entry_idx++) {
+        for ( ; entry_idx < 50; entry_idx++) {
 
             if (fill_via_insertion) {
                 insert_entry(file_ptr,           /* H5F_t * file_ptr */
@@ -27431,7 +27431,7 @@ check_metadata_blizzard_absence(hbool_t fill_via_insertion, unsigned paged)
          * After each insertion, verify the expected status of the
          * entries in the cache.
          */
-        for (entry_idx = entry_idx; entry_idx < 100; entry_idx++) {
+        for ( ; entry_idx < 100; entry_idx++) {
 
             if (fill_via_insertion) {
                 insert_entry(file_ptr,           /* H5F_t * file_ptr */
@@ -33243,7 +33243,7 @@ check_metadata_cork(hbool_t fill_via_insertion, unsigned paged)
 
         /* Fill out the rest of the cache with entries */
         /* Verify expected status of entries after each insertion */
-        for (entry_idx = entry_idx; entry_idx < 50; entry_idx++) {
+        for ( ; entry_idx < 50; entry_idx++) {
 
             if (fill_via_insertion) {
                 insert_entry(file_ptr,           /* H5F_t * file_ptr */
@@ -33304,7 +33304,7 @@ check_metadata_cork(hbool_t fill_via_insertion, unsigned paged)
     if (pass) {
 
         /* Insert 50 more entries (indices 50-99) into the cache.  */
-        for (entry_idx = entry_idx; entry_idx < 100; entry_idx++) {
+        for ( ; entry_idx < 100; entry_idx++) {
 
             if (fill_via_insertion) {
                 insert_entry(file_ptr,           /* H5F_t * file_ptr */
diff --git a/test/filter_plugin2_dsets.c b/test/filter_plugin2_dsets.c
index 08be78cee39..4a881aa8f9d 100644
--- a/test/filter_plugin2_dsets.c
+++ b/test/filter_plugin2_dsets.c
@@ -73,7 +73,7 @@ mult_div_value(unsigned int flags, size_t cd_nelmts, const unsigned int *cd_valu
         return 0;
 
     /* Assignment to eliminate unused parameter warning */
-    cd_values = cd_values;
+    (void)cd_values;
 
     if (flags & H5Z_FLAG_REVERSE) {
         /* READ - Divide the original value by MULTIPLIER */
diff --git a/test/filter_plugin4_groups.c b/test/filter_plugin4_groups.c
index 237642d2009..c948491d80c 100644
--- a/test/filter_plugin4_groups.c
+++ b/test/filter_plugin4_groups.c
@@ -74,7 +74,7 @@ append_to_group_name(unsigned int flags, size_t cd_nelmts, const unsigned int *c
         return 0;
 
     /* Assignment to eliminate unused parameter warning. */
-    cd_values = cd_values;
+    (void)cd_values;
 
     if (flags & H5Z_FLAG_REVERSE) {
         /* READ - Remove the suffix from the group name */
diff --git a/test/ros3.c b/test/ros3.c
index 9fb3ebe51ff..827fff80c91 100644
--- a/test/ros3.c
+++ b/test/ros3.c
@@ -865,7 +865,7 @@ test_vfd_open(void)
         if (T.which_fapl == FAPL_FILE_ACCESS)
             _fapl_id = fapl_file_access;
         else if (T.which_fapl == FAPL_ROS3_ANON)
-            _fapl_id = fapl_id;
+             _fapl_id = fapl_id;
 
         H5E_BEGIN_TRY { fd = H5FDopen(T.url, T.flags, _fapl_id, T.maxaddr); }
         H5E_END_TRY;
diff --git a/tools/test/h5copy/dynlib_copy.c b/tools/test/h5copy/dynlib_copy.c
index 57de3bc15a8..56be5a62947 100644
--- a/tools/test/h5copy/dynlib_copy.c
+++ b/tools/test/h5copy/dynlib_copy.c
@@ -70,7 +70,7 @@ H5Z_filter_dynlibud(unsigned int flags, size_t cd_nelmts, const unsigned int *cd
         return (0);
 
     /* Assignment to eliminate unused parameter warning. */
-    cd_values = cd_values;
+    (void)cd_values;
 
     if (flags & H5Z_FLAG_REVERSE) { /*read*/
         /* Subtract the original value with MULTIPLIER */
diff --git a/tools/test/h5diff/dynlib_diff.c b/tools/test/h5diff/dynlib_diff.c
index 4568ca17981..cebe53c0f9d 100644
--- a/tools/test/h5diff/dynlib_diff.c
+++ b/tools/test/h5diff/dynlib_diff.c
@@ -70,7 +70,7 @@ H5Z_filter_dynlibud(unsigned int flags, size_t cd_nelmts, const unsigned int *cd
         return (0);
 
     /* Assignment to eliminate unused parameter warning. */
-    cd_values = cd_values;
+    (void)cd_values;
 
     if (flags & H5Z_FLAG_REVERSE) { /*read*/
         /* Subtract the original value with MULTIPLIER */
diff --git a/tools/test/h5dump/dynlib_dump.c b/tools/test/h5dump/dynlib_dump.c
index 4568ca17981..cebe53c0f9d 100644
--- a/tools/test/h5dump/dynlib_dump.c
+++ b/tools/test/h5dump/dynlib_dump.c
@@ -70,7 +70,7 @@ H5Z_filter_dynlibud(unsigned int flags, size_t cd_nelmts, const unsigned int *cd
         return (0);
 
     /* Assignment to eliminate unused parameter warning. */
-    cd_values = cd_values;
+    (void)cd_values;
 
     if (flags & H5Z_FLAG_REVERSE) { /*read*/
         /* Subtract the original value with MULTIPLIER */
diff --git a/tools/test/h5dump/h5dumpgentest.c b/tools/test/h5dump/h5dumpgentest.c
index 5507ede1b7e..162dabeed3a 100644
--- a/tools/test/h5dump/h5dumpgentest.c
+++ b/tools/test/h5dump/h5dumpgentest.c
@@ -10921,7 +10921,7 @@ H5Z_filter_dynlibud(unsigned int flags, size_t cd_nelmts, const unsigned int *cd
         return (0);
 
     /* Assignment to eliminate unused parameter warning. */
-    cd_values = cd_values;
+    (void)cd_values;
 
     if (flags & H5Z_FLAG_REVERSE) { /*read*/
         /* Subtract the original value with MULTIPLIER */
diff --git a/tools/test/h5ls/dynlib_ls.c b/tools/test/h5ls/dynlib_ls.c
index 4568ca17981..cebe53c0f9d 100644
--- a/tools/test/h5ls/dynlib_ls.c
+++ b/tools/test/h5ls/dynlib_ls.c
@@ -70,7 +70,7 @@ H5Z_filter_dynlibud(unsigned int flags, size_t cd_nelmts, const unsigned int *cd
         return (0);
 
     /* Assignment to eliminate unused parameter warning. */
-    cd_values = cd_values;
+    (void)cd_values;
 
     if (flags & H5Z_FLAG_REVERSE) { /*read*/
         /* Subtract the original value with MULTIPLIER */