Many fixes to various compiler warnings (#3124)

* Fixed various -Wmissing-variable-declarations by adding static keyword
* In a few cases, renamed the variable suffix from _g to _s.
* Fixed some -Wmissing-variable-declarations by using different declaration macros
* Fixed various -Wconditional-uninitialized warnings by just initializing variable to zero
* Fixed various -Wcomma warnings
* Fixed clang -Wstrict-prototypes warnings
* Fixed various -Wunused-variable warnings
* Updated some casts to fix the only 3 -Wcast-qual warnings
* Fixed the only -Wsometimes-uninitialized warning

2 files changed, 9 insertions, 8 deletions

diff --git a/c++/examples/h5tutr_extend.cpp b/c++/examples/h5tutr_extend.cpp
index ff5ddab..3916f9a 100644
--- a/c++/examples/h5tutr_extend.cpp
+++ b/c++/examples/h5tutr_extend.cpp
@@ -99,7 +99,7 @@ main(void)
         // ---------------------------------------
 
         int     rdata[10][3];
-        int     i, j, rank, rank_chunk;
+        int     i, j, rank;
         hsize_t chunk_dimsr[2], dimsr[2];
 
         // Open the file and dataset.
@@ -111,12 +111,13 @@ main(void)
         prop      = dataset->getCreatePlist();
 
         // Get information to obtain memory dataspace.
-        rank            = filespace->getSimpleExtentNdims();
-        herr_t status_n = filespace->getSimpleExtentDims(dimsr);
+        rank = filespace->getSimpleExtentNdims();
+        (void)filespace->getSimpleExtentDims(dimsr);
 
-        if (H5D_CHUNKED == prop.getLayout())
-            rank_chunk = prop.getChunk(rank, chunk_dimsr);
-        cout << "rank chunk = " << rank_chunk << endl;
+        if (H5D_CHUNKED == prop.getLayout()) {
+            int rank_chunk = prop.getChunk(rank, chunk_dimsr);
+            cout << "rank chunk = " << rank_chunk << endl;
+        }
 
         memspace = new DataSpace(rank, dimsr, NULL);
         dataset->read(rdata, PredType::NATIVE_INT, *memspace, *filespace);
diff --git a/c++/examples/readdata.cpp b/c++/examples/readdata.cpp
index 1deed36..bfc03ee 100644
--- a/c++/examples/readdata.cpp
+++ b/c++/examples/readdata.cpp
@@ -84,7 +84,7 @@ main(void)
              * Get order of datatype and print message if it's a little endian.
              */
             H5std_string order_string;
-            H5T_order_t  order = intype.getOrder(order_string);
+            (void)intype.getOrder(order_string);
             cout << order_string << endl;
 
             /*
@@ -109,7 +109,7 @@ main(void)
          * display them.
          */
         hsize_t dims_out[2];
-        int     ndims = dataspace.getSimpleExtentDims(dims_out, NULL);
+        (void)dataspace.getSimpleExtentDims(dims_out, NULL);
         cout << "rank " << rank << ", dimensions " << (unsigned long)(dims_out[0]) << " x "
              << (unsigned long)(dims_out[1]) << endl;