Various warning fixes (#1812)

* Fixed -Wreserved-id-macro warnings from header include guards

* Removed all __int64 and LL suffix stuff now that C99 is minimum requirement

* Rename `H5FD_CTL__` to `H5FD_CTL_` to fix -Wreserved-id-macro warnings

Double underscore is reserved in C++ and this public header should be C++ compatible.

* Never define __STDC_FORMAT_MACROS anymore

Defining it causes a -Wreserved-id-macro.

Happily, according to the C++11 standard:

"The macros defined by <stdint> are provided unconditionally. In particular, the symbols __STDC_LIMIT_MACROS and __STDC_CONSTANT_MACROS (mentioned in C99 footnotes 219, 220, and 222) play no role in C++."

https://cplusplus.github.io/LWG/issue984

So looks like it's not necessary to define it with reasonably new toolchains.

* Fixed some -Wunused-macros warnings, removed dead code

* Fixed all -Wdouble-promotion warnings in C++ files

* Fixed remaining -Wsuggest-destructor-override warnings

* Committing clang-format changes

Co-authored-by: github-actions <41898282+github-actions[bot]@users.noreply.github.com>

5 files changed, 7 insertions, 19 deletions

diff --git a/c++/test/dsets.cpp b/c++/test/dsets.cpp
index 55ffd67..6e170bf 100644
--- a/c++/test/dsets.cpp
+++ b/c++/test/dsets.cpp
@@ -1201,7 +1201,7 @@ test_chunk_cache(const FileAccPropList &fapl)
 
         // Retrieve and verify the raw data chunk cache parameters
         nslots_4 = nbytes_4 = 0;
-        w0_4                = 0.0F;
+        w0_4                = 0.0;
         dapl2.getChunkCache(nslots_4, nbytes_4, w0_4);
         verify_val(nslots_2, nslots_4, "DSetCreatPropList::getChunkCache", __LINE__, __FILE__);
         verify_val(nbytes_2, nbytes_4, "DSetCreatPropList::getChunkCache", __LINE__, __FILE__);
diff --git a/c++/test/h5cpputil.h b/c++/test/h5cpputil.h
index 444bc68..86bc9d7 100644
--- a/c++/test/h5cpputil.h
+++ b/c++/test/h5cpputil.h
@@ -50,14 +50,14 @@ class InvalidActionException : public Exception {
   public:
     InvalidActionException(const H5std_string &func_name, const H5std_string &message = DEFAULT_MSG);
     InvalidActionException();
-    virtual ~InvalidActionException() throw();
+    ~InvalidActionException() throw() override;
 };
 
 class TestFailedException : public Exception {
   public:
     TestFailedException(const H5std_string &func_name, const H5std_string &message = DEFAULT_MSG);
     TestFailedException();
-    virtual ~TestFailedException() throw();
+    ~TestFailedException() throw() override;
 };
 
 // Overloaded/Template functions to verify values and display proper info
diff --git a/c++/test/tfilter.cpp b/c++/test/tfilter.cpp
index e89838c..b5073e8 100644
--- a/c++/test/tfilter.cpp
+++ b/c++/test/tfilter.cpp
@@ -27,8 +27,10 @@ using namespace H5;
 #include "h5test.h"
 #include "h5cpputil.h" // C++ utilility header file
 
-#define DSET_DIM1         100
-#define DSET_DIM2         200
+#ifdef H5_HAVE_FILTER_SZIP
+#define DSET_DIM1 100
+#define DSET_DIM2 200
+#endif
 #define FILTER_CHUNK_DIM1 2
 #define FILTER_CHUNK_DIM2 25
 
diff --git a/c++/test/trefer.cpp b/c++/test/trefer.cpp
index 53a4ed3..66fa040 100644
--- a/c++/test/trefer.cpp
+++ b/c++/test/trefer.cpp
@@ -395,7 +395,6 @@ test_reference_obj()
 #define GROUPNAME3 "group3"
 #define DSETNAME   "/dset"
 #define DSETNAME2  "dset2"
-#define NAME_SIZE  16
 
 static void
 test_reference_group()
diff --git a/c++/test/ttypes.cpp b/c++/test/ttypes.cpp
index 8afb4bb..794820e 100644
--- a/c++/test/ttypes.cpp
+++ b/c++/test/ttypes.cpp
@@ -28,12 +28,6 @@ using namespace H5;
 #include "h5cpputil.h" // C++ utilility header file
 
 /*
- * Offset from aligned memory returned by malloc().  This can be used to test
- * that type conversions handle non-aligned buffers correctly.
- */
-#define ALIGNMENT 1
-
-/*
  * Define if you want to test alignment code on a machine that doesn't
  * normally require alignment. When set, all native datatypes must be aligned
  * on a byte boundary equal to the data size.
@@ -53,13 +47,6 @@ using namespace H5;
 
 const char *FILENAME[] = {"dtypes1.h5", "dtypes2.h5", "dtypes3.h5", "dtypes4.h5", NULL};
 
-/*
- * Count up or down depending on whether the machine is big endian or little
- * endian.  If local variable `endian' is H5T_ORDER_BE then the result will
- * be I, otherwise the result will be Z-(I+1).
- */
-#define ENDIAN(Z, I) (H5T_ORDER_BE == endian ? (I) : (Z) - ((I) + 1))
-
 typedef enum flt_t { FLT_FLOAT, FLT_DOUBLE, FLT_LDOUBLE, FLT_OTHER } flt_t;
 
 typedef enum int_t {