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>

37 files changed, 143 insertions, 304 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 {
diff --git a/config/cmake/H5pubconf.h.in b/config/cmake/H5pubconf.h.in
index 9a581cb..4b2d2ee 100644
--- a/config/cmake/H5pubconf.h.in
+++ b/config/cmake/H5pubconf.h.in
@@ -464,9 +464,6 @@
 /* Define Fortran Maximum Real Decimal Precision */
 #define H5_PAC_FC_MAX_REAL_PRECISION @H5_PAC_FC_MAX_REAL_PRECISION@
 
-/* Width for printf() for type `long long' or `__int64', use `ll' */
-#cmakedefine H5_PRINTF_LL_WIDTH @H5_PRINTF_LL_WIDTH@
-
 /* The size of `bool', as computed by sizeof. */
 #cmakedefine H5_SIZEOF_BOOL @H5_SIZEOF_BOOL@
 
@@ -559,8 +556,7 @@
 
 #endif
 
-/* Define size of long long and/or __int64 bit integer type only if the type
-   exists.  */
+/* The size of `long long', as computed by sizeof. */
 #if !defined(__APPLE__)
  #cmakedefine H5_SIZEOF_LONG_LONG @H5_SIZEOF_LONG_LONG@
 #else
@@ -627,9 +623,6 @@
 /* The size of `__float128', as computed by sizeof. */
 #define H5_SIZEOF___FLOAT128 @H5_SIZEOF___FLOAT128@
 
-/* The size of `__int64', as computed by sizeof. */
-#define H5_SIZEOF___INT64 @H5_SIZEOF___INT64@
-
 /* Define if strict file format checks are enabled */
 #cmakedefine H5_STRICT_FORMAT_CHECKS @H5_STRICT_FORMAT_CHECKS@
 
diff --git a/config/cmake_ext_mod/ConfigureChecks.cmake b/config/cmake_ext_mod/ConfigureChecks.cmake
index 6242b12..c4516c7 100644
--- a/config/cmake_ext_mod/ConfigureChecks.cmake
+++ b/config/cmake_ext_mod/ConfigureChecks.cmake
@@ -326,10 +326,6 @@ if (NOT APPLE)
   HDF_CHECK_TYPE_SIZE (long         ${HDF_PREFIX}_SIZEOF_LONG)
 endif ()
 HDF_CHECK_TYPE_SIZE ("long long"    ${HDF_PREFIX}_SIZEOF_LONG_LONG)
-HDF_CHECK_TYPE_SIZE (__int64        ${HDF_PREFIX}_SIZEOF___INT64)
-if (NOT ${HDF_PREFIX}_SIZEOF___INT64)
-  set (${HDF_PREFIX}_SIZEOF___INT64 0)
-endif ()
 
 HDF_CHECK_TYPE_SIZE (float          ${HDF_PREFIX}_SIZEOF_FLOAT)
 HDF_CHECK_TYPE_SIZE (double         ${HDF_PREFIX}_SIZEOF_DOUBLE)
@@ -567,54 +563,6 @@ if (WINDOWS)
   endif ()
 endif ()
 
-#-----------------------------------------------------------------------------
-# Check how to print a Long Long integer
-#-----------------------------------------------------------------------------
-if (NOT ${HDF_PREFIX}_PRINTF_LL_WIDTH OR ${HDF_PREFIX}_PRINTF_LL_WIDTH MATCHES "unknown")
-  set (PRINT_LL_FOUND 0)
-  if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-    message (VERBOSE "Checking for appropriate format for 64 bit long:")
-  endif ()
-  set (CURRENT_TEST_DEFINITIONS "-DPRINTF_LL_WIDTH")
-  if (${HDF_PREFIX}_SIZEOF_LONG_LONG)
-    set (CURRENT_TEST_DEFINITIONS "${CURRENT_TEST_DEFINITIONS} -DHAVE_LONG_LONG")
-  endif ()
-  TRY_RUN (${HDF_PREFIX}_PRINTF_LL_TEST_RUN   ${HDF_PREFIX}_PRINTF_LL_TEST_COMPILE
-      ${CMAKE_BINARY_DIR}
-      ${HDF_RESOURCES_EXT_DIR}/HDFTests.c
-      COMPILE_DEFINITIONS "${CURRENT_TEST_DEFINITIONS}"
-      RUN_OUTPUT_VARIABLE OUTPUT
-  )
-  if (${HDF_PREFIX}_PRINTF_LL_TEST_COMPILE)
-    if (${HDF_PREFIX}_PRINTF_LL_TEST_RUN MATCHES 0)
-      string(REGEX REPLACE ".*PRINTF_LL_WIDTH=\\[(.*)\\].*" "\\1" ${HDF_PREFIX}_PRINTF_LL "${OUTPUT}")
-      set (${HDF_PREFIX}_PRINTF_LL_WIDTH "\"${${HDF_PREFIX}_PRINTF_LL}\"" CACHE INTERNAL "Width for printf for type `long long' or `__int64', us. `ll")
-      set (PRINT_LL_FOUND 1)
-    else ()
-      if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-        message (VERBOSE "Width test failed with result: ${${HDF_PREFIX}_PRINTF_LL_TEST_RUN}")
-      endif ()
-    endif ()
-  else ()
-    file (APPEND ${CMAKE_BINARY_DIR}/CMakeFiles/CMakeError.log
-        "Test ${HDF_PREFIX}_PRINTF_LL_WIDTH failed\n"
-    )
-  endif ()
-
-  if (PRINT_LL_FOUND)
-    if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-      message (VERBOSE "Checking for appropriate format for 64 bit long: found ${${HDF_PREFIX}_PRINTF_LL_WIDTH}")
-    endif ()
-  else ()
-    if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-      message (VERBOSE "Checking for appropriate format for 64 bit long: not found")
-    endif ()
-    set (${HDF_PREFIX}_PRINTF_LL_WIDTH "\"unknown\"" CACHE INTERNAL
-        "Width for printf for type `long long' or `__int64', us. `ll"
-    )
-  endif ()
-endif ()
-
 # ----------------------------------------------------------------------
 # Set the flag to indicate that the machine can handle converting
 # denormalized floating-point values.
diff --git a/config/cmake_ext_mod/HDFTests.c b/config/cmake_ext_mod/HDFTests.c
index 2b2a202..16686ba 100644
--- a/config/cmake_ext_mod/HDFTests.c
+++ b/config/cmake_ext_mod/HDFTests.c
@@ -80,54 +80,6 @@ SIMPLE_TEST(timezone=0);
 
 #endif /* HAVE_TIMEZONE */
 
-#ifdef PRINTF_LL_WIDTH
-
-#ifdef HAVE_LONG_LONG
-#  define LL_TYPE long long
-#else /* HAVE_LONG_LONG */
-#  define LL_TYPE __int64
-#endif /* HAVE_LONG_LONG */
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-
-#if defined(_MSC_VER) && defined(_DEBUG)
-# include <crtdbg.h>
-int DebugReport(int reportType, char* message, int* returnValue)
-{
-  (void)reportType;
-  (void)message;
-  (void)returnValue;
-  return 1; /* no further handling required */
-}
-#endif
-
-int main(void)
-{
-  char *llwidthArgs[] = { "I64", "l64", "ll", "l", "L", "q", NULL };
-  char *s = malloc(128);
-  char **currentArg = NULL;
-  LL_TYPE x = (LL_TYPE)1048576 * (LL_TYPE)1048576;
-  #if defined(_MSC_VER) && defined(_DEBUG)
-    _CrtSetReportHook(DebugReport);
-  #endif
-  for (currentArg = llwidthArgs; *currentArg != NULL; currentArg++)
-    {
-    char formatString[64];
-    snprintf(formatString, sizeof(formatString), "%%%sd", *currentArg);
-    snprintf(s, 128, formatString, x);
-    if (strcmp(s, "1099511627776") == 0)
-      {
-      printf("PRINTF_LL_WIDTH=[%s]\n", *currentArg);
-      return 0;
-      }
-    }
-  return 1;
-}
-
-#endif /* PRINTF_LL_WIDTH */
-
 #ifdef SYSTEM_SCOPE_THREADS
 #include <stdlib.h>
 #include <pthread.h>
diff --git a/config/ibm-aix b/config/ibm-aix
index f48f9d8..9f261e3 100644
--- a/config/ibm-aix
+++ b/config/ibm-aix
@@ -149,8 +149,6 @@ ac_cv_sizeof_char=${ac_cv_sizeof_char=1}
 ac_cv_sizeof_short=${ac_cv_sizeof_short=2}
 ac_cv_sizeof_int=${ac_cv_sizeof_int=4}
 ac_cv_sizeof_long_long=${ac_cv_sizeof_long_long=8}
-# Do not cache __int64 since it is not a standard C type and some compilers
-# (e.g., gcc) does not support it.
 ac_cv_sizeof_float=${ac_cv_sizeof_float=4}
 ac_cv_sizeof_double=${ac_cv_sizeof_double=8}
 ac_cv_sizeof_long_double=${ac_cv_sizeof_long_double=8}
diff --git a/configure.ac b/configure.ac
index 4fea5c4..575628f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -522,7 +522,6 @@ AC_CHECK_SIZEOF([int])
 AC_CHECK_SIZEOF([unsigned])
 AC_CHECK_SIZEOF([long])
 AC_CHECK_SIZEOF([long long])
-AC_CHECK_SIZEOF([__int64])
 AC_CHECK_SIZEOF([float])
 AC_CHECK_SIZEOF([double])
 AC_CHECK_SIZEOF([long double])
@@ -2146,33 +2145,6 @@ AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]], [[
                [AC_MSG_RESULT([no])])
 
 ## ----------------------------------------------------------------------
-## Try to figure out how to print `long long'.  Some machines use `%lld'
-## and others use `%qd'.  There may be more!  The final `l' is a
-## default in case none of the others work.
-##
-AC_MSG_CHECKING([how to print long long])
-AC_CACHE_VAL([hdf5_cv_printf_ll], [
-
-for hdf5_cv_printf_ll in ll l L q unknown; do
-   AC_RUN_IFELSE(
-        [AC_LANG_PROGRAM([
-            #include <stdio.h>
-            #include <stdlib.h>
-            #include <string.h>
-        ],[[
-            char *s = malloc(128);
-            long long x = (long long)1048576 * (long long)1048576;
-            snprintf(s,128,"%${hdf5_cv_printf_ll}d",x);
-            exit(strcmp(s,"1099511627776"));
-        ]])]
-   , [break],,[continue])
-done])
-
-AC_MSG_RESULT([%${hdf5_cv_printf_ll}d and %${hdf5_cv_printf_ll}u])
-AC_DEFINE_UNQUOTED([PRINTF_LL_WIDTH], ["$hdf5_cv_printf_ll"],
-                   [Width for printf() for type `long long' or `__int64', use `ll'])
-
-## ----------------------------------------------------------------------
 ## Remove old ways of determining debug/production build.
 ## These were used in 1.8.x and earlier. We should probably keep these checks
 ## around to help people migrate to 1.10.x and newer versions.
diff --git a/hl/c++/src/H5PacketTable.h b/hl/c++/src/H5PacketTable.h
index c1f1eb5..e395e5a 100644
--- a/hl/c++/src/H5PacketTable.h
+++ b/hl/c++/src/H5PacketTable.h
@@ -163,7 +163,7 @@ class H5_HLCPPDLL FL_PacketTable : virtual public PacketTable {
     /* Destructor
      * Cleans up the packet table
      */
-    virtual ~FL_PacketTable()
+    ~FL_PacketTable() override
     {
     }
 
diff --git a/java/src/jni/h5util.c b/java/src/jni/h5util.c
index 2de5d87..7ea09c8 100644
--- a/java/src/jni/h5util.c
+++ b/java/src/jni/h5util.c
@@ -211,9 +211,9 @@ h5str_convert(JNIEnv *env, char **in_str, hid_t container, hid_t tid, void *out_
 
     /* Build default formats for long long types */
     if (!fmt_llong[0]) {
-        if (HDsnprintf(fmt_llong, sizeof(fmt_llong), "%%%sd", H5_PRINTF_LL_WIDTH) < 0)
+        if (HDsnprintf(fmt_llong, sizeof(fmt_llong), "%%lld") < 0)
             H5_JNI_FATAL_ERROR(ENVONLY, "h5str_convert: HDsnprintf failure");
-        if (HDsnprintf(fmt_ullong, sizeof(fmt_ullong), "%%%su", H5_PRINTF_LL_WIDTH) < 0)
+        if (HDsnprintf(fmt_ullong, sizeof(fmt_ullong), "%%llu") < 0)
             H5_JNI_FATAL_ERROR(ENVONLY, "h5str_convert: HDsnprintf failure");
     } /* end if */
 
@@ -781,9 +781,9 @@ h5str_sprintf(JNIEnv *env, h5str_t *out_str, hid_t container, hid_t tid, void *i
 
     /* Build default formats for long long types */
     if (!fmt_llong[0]) {
-        if (HDsnprintf(fmt_llong, sizeof(fmt_llong), "%%%sd", H5_PRINTF_LL_WIDTH) < 0)
+        if (HDsnprintf(fmt_llong, sizeof(fmt_llong), "%%lld") < 0)
             H5_JNI_FATAL_ERROR(ENVONLY, "h5str_sprintf: HDsnprintf failure");
-        if (HDsnprintf(fmt_ullong, sizeof(fmt_ullong), "%%%su", H5_PRINTF_LL_WIDTH) < 0)
+        if (HDsnprintf(fmt_ullong, sizeof(fmt_ullong), "%%llu") < 0)
             H5_JNI_FATAL_ERROR(ENVONLY, "h5str_sprintf: HDsnprintf failure");
     } /* end if */
     switch (tclass) {
diff --git a/release_docs/RELEASE.txt b/release_docs/RELEASE.txt
index c8ecbd1..69d9780 100644
--- a/release_docs/RELEASE.txt
+++ b/release_docs/RELEASE.txt
@@ -109,7 +109,7 @@ New Features
 
     Internal header file:
     ---------------------
-    -
+    - All the #defines named H5FD_CTL__* were renamed to H5FD_CTL_*, i.e. the double underscore was reduced to a single underscore.
 
 
     Documentation:
diff --git a/src/H5Dcompact.c b/src/H5Dcompact.c
index 92252dc..94dc64d 100644
--- a/src/H5Dcompact.c
+++ b/src/H5Dcompact.c
@@ -285,7 +285,7 @@ H5D__compact_iovv_memmanage_cb(hsize_t dst_off, hsize_t src_off, size_t len, voi
         HGOTO_ERROR(H5E_IO, H5E_CANTGET, FAIL, "can't get file handle")
 
     /* Setup operation flags and arguments */
-    op_flags = H5FD_CTL__ROUTE_TO_TERMINAL_VFD_FLAG | H5FD_CTL__FAIL_IF_UNKNOWN_FLAG;
+    op_flags = H5FD_CTL_ROUTE_TO_TERMINAL_VFD_FLAG | H5FD_CTL_FAIL_IF_UNKNOWN_FLAG;
 
     op_args.dstbuf  = udata->dstbuf;
     op_args.dst_off = dst_off;
@@ -294,7 +294,7 @@ H5D__compact_iovv_memmanage_cb(hsize_t dst_off, hsize_t src_off, size_t len, voi
     op_args.len     = len;
 
     /* Make request to file driver */
-    if (H5FD_ctl(file_handle, H5FD_CTL__MEM_COPY, op_flags, &op_args, NULL) < 0)
+    if (H5FD_ctl(file_handle, H5FD_CTL_MEM_COPY, op_flags, &op_args, NULL) < 0)
         HGOTO_ERROR(H5E_IO, H5E_FCNTL, FAIL, "VFD memcpy request failed")
 
 done:
diff --git a/src/H5ESdevelop.h b/src/H5ESdevelop.h
index 2fb9aeb..5bbf74e 100644
--- a/src/H5ESdevelop.h
+++ b/src/H5ESdevelop.h
@@ -15,8 +15,8 @@
  *      support routines.
  */
 
-#ifndef _H5ESdevelop_H
-#define _H5ESdevelop_H
+#ifndef H5ESdevelop_H
+#define H5ESdevelop_H
 
 /* Include package's public header */
 #include "H5ESpublic.h"
@@ -49,4 +49,4 @@ H5_DLL herr_t H5ESget_requests(hid_t es_id, H5_iter_order_t order, hid_t *connec
 }
 #endif
 
-#endif /* _H5ESdevelop_H */
+#endif /* H5ESdevelop_H */
diff --git a/src/H5FD.c b/src/H5FD.c
index 6584843..162e27f 100644
--- a/src/H5FD.c
+++ b/src/H5FD.c
@@ -2180,7 +2180,7 @@ H5FD_ctl(H5FD_t *file, uint64_t op_code, uint64_t flags, const void *input, void
 
     /* Dispatch to driver if the ctl function exists.
      *
-     * If it doesn't, fail if the H5FD_CTL__FAIL_IF_UNKNOWN_FLAG is set.
+     * If it doesn't, fail if the H5FD_CTL_FAIL_IF_UNKNOWN_FLAG is set.
      *
      * Otherwise, report success.
      */
@@ -2190,7 +2190,7 @@ H5FD_ctl(H5FD_t *file, uint64_t op_code, uint64_t flags, const void *input, void
 
             HGOTO_ERROR(H5E_VFL, H5E_FCNTL, FAIL, "VFD ctl request failed")
     }
-    else if (flags & H5FD_CTL__FAIL_IF_UNKNOWN_FLAG) {
+    else if (flags & H5FD_CTL_FAIL_IF_UNKNOWN_FLAG) {
 
         HGOTO_ERROR(H5E_VFL, H5E_FCNTL, FAIL,
                     "VFD ctl request failed (no ctl callback and fail if unknown flag is set)")
diff --git a/src/H5FDdevelop.h b/src/H5FDdevelop.h
index f5b32ed..50eae1f 100644
--- a/src/H5FDdevelop.h
+++ b/src/H5FDdevelop.h
@@ -15,8 +15,8 @@
  *      support routines.
  */
 
-#ifndef _H5FDdevelop_H
-#define _H5FDdevelop_H
+#ifndef H5FDdevelop_H
+#define H5FDdevelop_H
 
 /* Include package's public header */
 #include "H5FDpublic.h"
@@ -292,4 +292,4 @@ H5_DLL herr_t  H5FDctl(H5FD_t *file, uint64_t op_code, uint64_t flags, const voi
 }
 #endif
 
-#endif /* _H5FDdevelop_H */
+#endif /* H5FDdevelop_H */
diff --git a/src/H5FDmpi.c b/src/H5FDmpi.c
index 7eb1463..45791e8 100644
--- a/src/H5FDmpi.c
+++ b/src/H5FDmpi.c
@@ -57,7 +57,7 @@ int
 H5FD_mpi_get_rank(H5FD_t *file)
 {
     const H5FD_class_t *cls;
-    uint64_t            flags    = H5FD_CTL__FAIL_IF_UNKNOWN_FLAG | H5FD_CTL__ROUTE_TO_TERMINAL_VFD_FLAG;
+    uint64_t            flags    = H5FD_CTL_FAIL_IF_UNKNOWN_FLAG | H5FD_CTL_ROUTE_TO_TERMINAL_VFD_FLAG;
     int                 rank     = -1;
     void *              rank_ptr = (void *)(&rank);
     int                 ret_value;
@@ -70,7 +70,7 @@ H5FD_mpi_get_rank(H5FD_t *file)
     HDassert(cls->ctl); /* All MPI drivers must implement this */
 
     /* Dispatch to driver */
-    if ((cls->ctl)(file, H5FD_CTL__GET_MPI_RANK_OPCODE, flags, NULL, &rank_ptr) < 0)
+    if ((cls->ctl)(file, H5FD_CTL_GET_MPI_RANK_OPCODE, flags, NULL, &rank_ptr) < 0)
         HGOTO_ERROR(H5E_VFL, H5E_CANTGET, FAIL, "driver get_rank request failed")
 
     HDassert(rank >= 0);
@@ -109,7 +109,7 @@ int
 H5FD_mpi_get_size(H5FD_t *file)
 {
     const H5FD_class_t *cls;
-    uint64_t            flags    = H5FD_CTL__FAIL_IF_UNKNOWN_FLAG | H5FD_CTL__ROUTE_TO_TERMINAL_VFD_FLAG;
+    uint64_t            flags    = H5FD_CTL_FAIL_IF_UNKNOWN_FLAG | H5FD_CTL_ROUTE_TO_TERMINAL_VFD_FLAG;
     int                 size     = 0;
     void *              size_ptr = (void *)(&size);
     int                 ret_value;
@@ -122,7 +122,7 @@ H5FD_mpi_get_size(H5FD_t *file)
     HDassert(cls->ctl); /* All MPI drivers must implement this */
 
     /* Dispatch to driver */
-    if ((cls->ctl)(file, H5FD_CTL__GET_MPI_SIZE_OPCODE, flags, NULL, &size_ptr) < 0)
+    if ((cls->ctl)(file, H5FD_CTL_GET_MPI_SIZE_OPCODE, flags, NULL, &size_ptr) < 0)
         HGOTO_ERROR(H5E_VFL, H5E_CANTGET, FAIL, "driver get_size request failed")
 
     if (0 >= size)
@@ -162,7 +162,7 @@ MPI_Comm
 H5FD_mpi_get_comm(H5FD_t *file)
 {
     const H5FD_class_t *cls;
-    uint64_t            flags    = H5FD_CTL__FAIL_IF_UNKNOWN_FLAG | H5FD_CTL__ROUTE_TO_TERMINAL_VFD_FLAG;
+    uint64_t            flags    = H5FD_CTL_FAIL_IF_UNKNOWN_FLAG | H5FD_CTL_ROUTE_TO_TERMINAL_VFD_FLAG;
     MPI_Comm            comm     = MPI_COMM_NULL;
     void *              comm_ptr = (void *)(&comm);
     MPI_Comm            ret_value;
@@ -175,7 +175,7 @@ H5FD_mpi_get_comm(H5FD_t *file)
     HDassert(cls->ctl); /* All MPI drivers must implement this */
 
     /* Dispatch to driver */
-    if ((cls->ctl)(file, H5FD_CTL__GET_MPI_COMMUNICATOR_OPCODE, flags, NULL, &comm_ptr) < 0)
+    if ((cls->ctl)(file, H5FD_CTL_GET_MPI_COMMUNICATOR_OPCODE, flags, NULL, &comm_ptr) < 0)
         HGOTO_ERROR(H5E_VFL, H5E_CANTGET, MPI_COMM_NULL, "driver get_comm request failed")
 
     if (comm == MPI_COMM_NULL)
diff --git a/src/H5FDmpio.c b/src/H5FDmpio.c
index 1be4779..ce32bc7 100644
--- a/src/H5FDmpio.c
+++ b/src/H5FDmpio.c
@@ -3017,9 +3017,9 @@ done:
  *
  *              At present, the supported op codes are:
  *
- *                  H5FD_CTL__GET_MPI_COMMUNICATOR_OPCODE
- *                  H5FD_CTL__GET_MPI_RANK_OPCODE
- *                  H5FD_CTL__GET_MPI_SIZE_OPCODE
+ *                  H5FD_CTL_GET_MPI_COMMUNICATOR_OPCODE
+ *                  H5FD_CTL_GET_MPI_RANK_OPCODE
+ *                  H5FD_CTL_GET_MPI_SIZE_OPCODE
  *
  *              Note that these opcodes must be supported by all VFDs that
  *              support MPI.
@@ -3045,26 +3045,26 @@ H5FD__mpio_ctl(H5FD_t *_file, uint64_t op_code, uint64_t flags, const void H5_AT
 
     switch (op_code) {
 
-        case H5FD_CTL__GET_MPI_COMMUNICATOR_OPCODE:
+        case H5FD_CTL_GET_MPI_COMMUNICATOR_OPCODE:
             HDassert(output);
             HDassert(*output);
             **((MPI_Comm **)output) = file->comm;
             break;
 
-        case H5FD_CTL__GET_MPI_RANK_OPCODE:
+        case H5FD_CTL_GET_MPI_RANK_OPCODE:
             HDassert(output);
             HDassert(*output);
             **((int **)output) = file->mpi_rank;
             break;
 
-        case H5FD_CTL__GET_MPI_SIZE_OPCODE:
+        case H5FD_CTL_GET_MPI_SIZE_OPCODE:
             HDassert(output);
             HDassert(*output);
             **((int **)output) = file->mpi_size;
             break;
 
         default: /* unknown op code */
-            if (flags & H5FD_CTL__FAIL_IF_UNKNOWN_FLAG) {
+            if (flags & H5FD_CTL_FAIL_IF_UNKNOWN_FLAG) {
 
                 HGOTO_ERROR(H5E_VFL, H5E_FCNTL, FAIL, "unknown op_code and fail if unknown")
             }
diff --git a/src/H5FDmulti.c b/src/H5FDmulti.c
index 20c538f..0d5bedf 100644
--- a/src/H5FDmulti.c
+++ b/src/H5FDmulti.c
@@ -2268,7 +2268,7 @@ H5FD_multi_ctl(H5FD_t *_file, uint64_t op_code, uint64_t flags, const void *inpu
     switch (op_code) {
         /* Unknown op code */
         default:
-            if (flags & H5FD_CTL__FAIL_IF_UNKNOWN_FLAG)
+            if (flags & H5FD_CTL_FAIL_IF_UNKNOWN_FLAG)
                 H5Epush_ret(func, H5E_ERR_CLS, H5E_VFL, H5E_FCNTL,
                             "VFD ctl request failed (unknown op code and fail if unknown flag is set)", -1);
 
diff --git a/src/H5FDpublic.h b/src/H5FDpublic.h
index 221f569..5221e35 100644
--- a/src/H5FDpublic.h
+++ b/src/H5FDpublic.h
@@ -188,14 +188,14 @@
     (H5FD_CTL_OPC_RESERVED + 511) /* Maximum opcode value available for experimental use */
 
 /* ctl function op codes: */
-#define H5FD_CTL__INVALID_OPCODE              0
-#define H5FD_CTL__TEST_OPCODE                 1
-#define H5FD_CTL__GET_MPI_COMMUNICATOR_OPCODE 2
-#define H5FD_CTL__GET_MPI_RANK_OPCODE         3
-#define H5FD_CTL__GET_MPI_SIZE_OPCODE         4
-#define H5FD_CTL__MEM_ALLOC                   5
-#define H5FD_CTL__MEM_FREE                    6
-#define H5FD_CTL__MEM_COPY                    7
+#define H5FD_CTL_INVALID_OPCODE              0
+#define H5FD_CTL_TEST_OPCODE                 1
+#define H5FD_CTL_GET_MPI_COMMUNICATOR_OPCODE 2
+#define H5FD_CTL_GET_MPI_RANK_OPCODE         3
+#define H5FD_CTL_GET_MPI_SIZE_OPCODE         4
+#define H5FD_CTL_MEM_ALLOC                   5
+#define H5FD_CTL_MEM_FREE                    6
+#define H5FD_CTL_MEM_COPY                    7
 
 /* ctl function flags: */
 
@@ -227,7 +227,7 @@
  */
 
 /* Unknown op codes should be ignored silently unless the
- * H5FD_CTL__FAIL_IF_UNKNOWN_FLAG is set.
+ * H5FD_CTL_FAIL_IF_UNKNOWN_FLAG is set.
  *
  * On terminal VFDs, unknown op codes should generate an
  * error unconditionally if this flag is set.
@@ -237,9 +237,9 @@
  * flags.  In the absence of such flags, the VFD should
  * generate an error.
  */
-#define H5FD_CTL__FAIL_IF_UNKNOWN_FLAG 0x0001
+#define H5FD_CTL_FAIL_IF_UNKNOWN_FLAG 0x0001
 
-/* The H5FD_CTL__ROUTE_TO_TERMINAL_VFD_FLAG is used only
+/* The H5FD_CTL_ROUTE_TO_TERMINAL_VFD_FLAG is used only
  * by non-ternminal VFDs, and only applies to unknown
  * opcodes. (known op codes should be handled as
  * appropriate.)
@@ -249,9 +249,9 @@
  * the VFD stack en-route to the terminal VFD.
  * If that VFD does not support the ctl call, the
  * pass through VFD should fail or succeed as directed
- * by the  H5FD_CTL__FAIL_IF_UNKNOWN_FLAG.
+ * by the  H5FD_CTL_FAIL_IF_UNKNOWN_FLAG.
  */
-#define H5FD_CTL__ROUTE_TO_TERMINAL_VFD_FLAG 0x0002
+#define H5FD_CTL_ROUTE_TO_TERMINAL_VFD_FLAG 0x0002
 
 /*******************/
 /* Public Typedefs */
diff --git a/src/H5FDsec2.c b/src/H5FDsec2.c
index acc705e..1d97f83 100644
--- a/src/H5FDsec2.c
+++ b/src/H5FDsec2.c
@@ -1086,7 +1086,7 @@ H5FD__sec2_ctl(H5FD_t *_file, uint64_t H5_ATTR_UNUSED op_code, uint64_t flags,
     HDassert(_file);
 
     /* No op codes are understood. */
-    if (flags & H5FD_CTL__FAIL_IF_UNKNOWN_FLAG)
+    if (flags & H5FD_CTL_FAIL_IF_UNKNOWN_FLAG)
         HGOTO_ERROR(H5E_VFL, H5E_FCNTL, FAIL, "unknown op_code and fail if unknown flag is set")
 
 done:
diff --git a/src/H5FDsplitter.c b/src/H5FDsplitter.c
index 3d7093a..48de4e6 100644
--- a/src/H5FDsplitter.c
+++ b/src/H5FDsplitter.c
@@ -1325,16 +1325,16 @@ H5FD__splitter_ctl(H5FD_t *_file, uint64_t op_code, uint64_t flags, const void *
     switch (op_code) {
         /* Unknown op code */
         default:
-            if (flags & H5FD_CTL__ROUTE_TO_TERMINAL_VFD_FLAG) {
+            if (flags & H5FD_CTL_ROUTE_TO_TERMINAL_VFD_FLAG) {
                 /* Pass ctl call down to R/W channel VFD */
                 if (H5FDctl(file->rw_file, op_code, flags, input, output) < 0)
                     HGOTO_ERROR(H5E_VFL, H5E_FCNTL, FAIL, "VFD ctl request failed")
             }
             else {
                 /* If no valid VFD routing flag is specified, fail for unknown op code
-                 * if H5FD_CTL__FAIL_IF_UNKNOWN_FLAG flag is set.
+                 * if H5FD_CTL_FAIL_IF_UNKNOWN_FLAG flag is set.
                  */
-                if (flags & H5FD_CTL__FAIL_IF_UNKNOWN_FLAG)
+                if (flags & H5FD_CTL_FAIL_IF_UNKNOWN_FLAG)
                     HGOTO_ERROR(H5E_VFL, H5E_FCNTL, FAIL,
                                 "VFD ctl request failed (unknown op code and fail if unknown flag is set)")
             }
diff --git a/src/H5Idevelop.h b/src/H5Idevelop.h
index 3cd951e..13e3a83 100644
--- a/src/H5Idevelop.h
+++ b/src/H5Idevelop.h
@@ -15,8 +15,8 @@
  *      support routines.
  */
 
-#ifndef _H5Idevelop_H
-#define _H5Idevelop_H
+#ifndef H5Idevelop_H
+#define H5Idevelop_H
 
 /* Include package's public header */
 #include "H5Ipublic.h" /* ID management */
@@ -136,4 +136,4 @@ H5_DLL hid_t H5Iregister_future(H5I_type_t type, const void *object, H5I_future_
 }
 #endif
 
-#endif /* _H5Idevelop_H */
+#endif /* H5Idevelop_H */
diff --git a/src/H5Ldevelop.h b/src/H5Ldevelop.h
index 43ed7de..96b2ec3 100644
--- a/src/H5Ldevelop.h
+++ b/src/H5Ldevelop.h
@@ -15,8 +15,8 @@
  *      support routines.
  */
 
-#ifndef _H5Ldevelop_H
-#define _H5Ldevelop_H
+#ifndef H5Ldevelop_H
+#define H5Ldevelop_H
 
 /* Include package's public header */
 #include "H5Lpublic.h"
@@ -311,4 +311,4 @@ typedef struct {
 
 #endif /* H5_NO_DEPRECATED_SYMBOLS */
 
-#endif /* _H5Ldevelop_H */
+#endif /* H5Ldevelop_H */
diff --git a/src/H5Tdevelop.h b/src/H5Tdevelop.h
index e642d7c..2ae4178 100644
--- a/src/H5Tdevelop.h
+++ b/src/H5Tdevelop.h
@@ -15,8 +15,8 @@
  *      support routines.
  */
 
-#ifndef _H5Tdevelop_H
-#define _H5Tdevelop_H
+#ifndef H5Tdevelop_H
+#define H5Tdevelop_H
 
 /* Include package's public header */
 #include "H5Tpublic.h"
@@ -224,4 +224,4 @@ H5_DLL htri_t H5Tcompiler_conv(hid_t src_id, hid_t dst_id);
 
 #endif /* H5_NO_DEPRECATED_SYMBOLS */
 
-#endif /* _H5Tdevelop_H */
+#endif /* H5Tdevelop_H */
diff --git a/src/H5Zdevelop.h b/src/H5Zdevelop.h
index 328e221..0f5e3e9 100644
--- a/src/H5Zdevelop.h
+++ b/src/H5Zdevelop.h
@@ -15,8 +15,8 @@
  *      support routines.
  */
 
-#ifndef _H5Zdevelop_H
-#define _H5Zdevelop_H
+#ifndef H5Zdevelop_H
+#define H5Zdevelop_H
 
 /* Include package's public header */
 #include "H5Zpublic.h"
@@ -418,4 +418,4 @@ typedef struct H5Z_class1_t {
 
 #endif /* H5_NO_DEPRECATED_SYMBOLS */
 
-#endif /* _H5Zdevelop_H */
+#endif /* H5Zdevelop_H */
diff --git a/src/H5public.h b/src/H5public.h
index 0be303b..26239d0 100644
--- a/src/H5public.h
+++ b/src/H5public.h
@@ -37,9 +37,10 @@
 
 /* C library header files for things that appear in HDF5 public headers */
 #ifdef __cplusplus
-#define __STDC_FORMAT_MACROS
-#endif
+#include <cinttypes>
+#else
 #include <inttypes.h>
+#endif
 #include <limits.h>
 #include <stdarg.h>
 #include <stdbool.h>
diff --git a/test/dt_arith.c b/test/dt_arith.c
index 3601b95..ae48045 100644
--- a/test/dt_arith.c
+++ b/test/dt_arith.c
@@ -2462,11 +2462,11 @@ test_conv_int_1(const char *name, hid_t src, hid_t dst)
                 break;
             case INT_LLONG:
                 HDmemcpy(aligned, saved + j * sizeof(long long), sizeof(long long));
-                HDfprintf(stdout, " %29" H5_PRINTF_LL_WIDTH "d\n", *((long long *)aligned));
+                HDfprintf(stdout, " %29lld\n", *((long long *)aligned));
                 break;
             case INT_ULLONG:
                 HDmemcpy(aligned, saved + j * sizeof(unsigned long long), sizeof(unsigned long long));
-                HDfprintf(stdout, " %29" H5_PRINTF_LL_WIDTH "u\n", *((unsigned long long *)aligned));
+                HDfprintf(stdout, " %29llu\n", *((unsigned long long *)aligned));
                 break;
             case FLT_FLOAT:
             case FLT_DOUBLE:
@@ -2516,11 +2516,11 @@ test_conv_int_1(const char *name, hid_t src, hid_t dst)
                 break;
             case INT_LLONG:
                 HDmemcpy(aligned, buf + j * sizeof(long long), sizeof(long long));
-                HDfprintf(stdout, " %29" H5_PRINTF_LL_WIDTH "d\n", *((long long *)aligned));
+                HDfprintf(stdout, " %29lld\n", *((long long *)aligned));
                 break;
             case INT_ULLONG:
                 HDmemcpy(aligned, buf + j * sizeof(long long), sizeof(unsigned long long));
-                HDfprintf(stdout, " %29" H5_PRINTF_LL_WIDTH "u\n", *((unsigned long long *)aligned));
+                HDfprintf(stdout, " %29llu\n", *((unsigned long long *)aligned));
                 break;
             case FLT_FLOAT:
             case FLT_DOUBLE:
@@ -2561,10 +2561,10 @@ test_conv_int_1(const char *name, hid_t src, hid_t dst)
                 HDprintf(" %29lu\n", *((unsigned long *)((void *)hw)));
                 break;
             case INT_LLONG:
-                HDfprintf(stdout, " %29" H5_PRINTF_LL_WIDTH "d\n", *((long long *)((void *)hw)));
+                HDfprintf(stdout, " %29lld\n", *((long long *)((void *)hw)));
                 break;
             case INT_ULLONG:
-                HDfprintf(stdout, " %29" H5_PRINTF_LL_WIDTH "u\n", *((unsigned long long *)((void *)hw)));
+                HDfprintf(stdout, " %29llu\n", *((unsigned long long *)((void *)hw)));
                 break;
             case FLT_FLOAT:
             case FLT_DOUBLE:
@@ -4398,11 +4398,11 @@ test_conv_int_fp(const char *name, int run_test, hid_t src, hid_t dst)
                 break;
             case INT_LLONG:
                 HDmemcpy(aligned, saved + j * sizeof(long long), sizeof(long long));
-                HDfprintf(stdout, " %29" H5_PRINTF_LL_WIDTH "d\n", *((long long *)aligned));
+                HDfprintf(stdout, " %29lld\n", *((long long *)aligned));
                 break;
             case INT_ULLONG:
                 HDmemcpy(aligned, saved + j * sizeof(unsigned long long), sizeof(unsigned long long));
-                HDfprintf(stdout, " %29" H5_PRINTF_LL_WIDTH "u\n", *((unsigned long long *)aligned));
+                HDfprintf(stdout, " %29llu\n", *((unsigned long long *)aligned));
                 break;
             case FLT_FLOAT:
                 HDmemcpy(aligned, saved + j * sizeof(float), sizeof(float));
@@ -4461,11 +4461,11 @@ test_conv_int_fp(const char *name, int run_test, hid_t src, hid_t dst)
                 break;
             case INT_LLONG:
                 HDmemcpy(aligned, buf + j * sizeof(long long), sizeof(long long));
-                HDfprintf(stdout, " %29" H5_PRINTF_LL_WIDTH "d\n", *((long long *)aligned));
+                HDfprintf(stdout, " %29lld\n", *((long long *)aligned));
                 break;
             case INT_ULLONG:
                 HDmemcpy(aligned, buf + j * sizeof(unsigned long long), sizeof(unsigned long long));
-                HDfprintf(stdout, " %29" H5_PRINTF_LL_WIDTH "u\n", *((unsigned long long *)aligned));
+                HDfprintf(stdout, " %29llu\n", *((unsigned long long *)aligned));
                 break;
             case FLT_FLOAT:
                 HDmemcpy(aligned, buf + j * sizeof(float), sizeof(float));
@@ -4515,10 +4515,10 @@ test_conv_int_fp(const char *name, int run_test, hid_t src, hid_t dst)
                 HDprintf(" %29lu\n", *((unsigned long *)((void *)hw)));
                 break;
             case INT_LLONG:
-                HDfprintf(stdout, " %29" H5_PRINTF_LL_WIDTH "d\n", *((long long *)((void *)hw)));
+                HDfprintf(stdout, " %29lld\n", *((long long *)((void *)hw)));
                 break;
             case INT_ULLONG:
-                HDfprintf(stdout, " %29" H5_PRINTF_LL_WIDTH "u\n", *((unsigned long long *)((void *)hw)));
+                HDfprintf(stdout, " %29llu\n", *((unsigned long long *)((void *)hw)));
                 break;
             case FLT_FLOAT:
                 HDprintf(" %29f\n", (double)*((float *)((void *)hw)));
diff --git a/test/tconfig.c b/test/tconfig.c
index 8bd625f..8cffd54 100644
--- a/test/tconfig.c
+++ b/test/tconfig.c
@@ -161,11 +161,6 @@ test_config_ctypes(void)
     vrfy_cint_type(int_least64_t, uint_least64_t, H5_SIZEOF_INT_LEAST64_T);
 #endif
 
-    /* pseudo standard basic types */
-#if H5_SIZEOF___INT64 > 0
-    vrfy_cint_type(__int64, unsigned __int64, H5_SIZEOF___INT64);
-#endif
-
 #if H5_SIZEOF_OFF_T > 0
     vrfy_ctype(off_t, H5_SIZEOF_OFF_T);
 #endif
diff --git a/test/vfd.c b/test/vfd.c
index 412f202..d6f6d61 100644
--- a/test/vfd.c
+++ b/test/vfd.c
@@ -3581,12 +3581,12 @@ H5FD__ctl_test_vfd_ctl(H5FD_t H5_ATTR_UNUSED *_file, uint64_t op_code, uint64_t
 
     switch (op_code) {
         /* Op code for testing purposes */
-        case H5FD_CTL__TEST_OPCODE:
+        case H5FD_CTL_TEST_OPCODE:
             break;
 
         /* Unknown op code */
         default:
-            if (flags & H5FD_CTL__FAIL_IF_UNKNOWN_FLAG)
+            if (flags & H5FD_CTL_FAIL_IF_UNKNOWN_FLAG)
                 ret_value = FAIL;
             break;
     }
@@ -3660,8 +3660,8 @@ run_ctl_test(uint64_t op_code, uint64_t flags, ctl_test_opc_type opc_type, hid_t
     char    filename[1024];
 
     /* Check for a few ctl function flags */
-    fail_if_unknown  = (flags & H5FD_CTL__FAIL_IF_UNKNOWN_FLAG);
-    routing_flag_set = (flags & H5FD_CTL__ROUTE_TO_TERMINAL_VFD_FLAG);
+    fail_if_unknown  = (flags & H5FD_CTL_FAIL_IF_UNKNOWN_FLAG);
+    routing_flag_set = (flags & H5FD_CTL_ROUTE_TO_TERMINAL_VFD_FLAG);
 
     /* Determine if the top-level VFD is a passthrough VFD */
     if ((driver_id = H5Pget_driver(fapl_id)) < 0)
@@ -3761,7 +3761,7 @@ test_ctl(void)
 
     TESTING_2("known op code to terminal VFD (without fail on unknown flag)");
 
-    op_code = H5FD_CTL__TEST_OPCODE;
+    op_code = H5FD_CTL_TEST_OPCODE;
     flags   = 0;
 
     /* H5FDctl call should succeed normally */
@@ -3772,8 +3772,8 @@ test_ctl(void)
 
     TESTING_2("known op code to terminal VFD (with fail on unknown flag)");
 
-    op_code = H5FD_CTL__TEST_OPCODE;
-    flags   = H5FD_CTL__FAIL_IF_UNKNOWN_FLAG;
+    op_code = H5FD_CTL_TEST_OPCODE;
+    flags   = H5FD_CTL_FAIL_IF_UNKNOWN_FLAG;
 
     /* H5FDctl call should succeed normally */
     if (run_ctl_test(op_code, flags, CTL_OPC_KNOWN_TERMINAL, fapl_id) < 0)
@@ -3783,8 +3783,8 @@ test_ctl(void)
 
     TESTING_2("known op code to terminal VFD (without fail on unknown flag/route to terminal VFD)");
 
-    op_code = H5FD_CTL__TEST_OPCODE;
-    flags   = H5FD_CTL__ROUTE_TO_TERMINAL_VFD_FLAG;
+    op_code = H5FD_CTL_TEST_OPCODE;
+    flags   = H5FD_CTL_ROUTE_TO_TERMINAL_VFD_FLAG;
 
     /* H5FDctl call should succeed normally */
     if (run_ctl_test(op_code, flags, CTL_OPC_KNOWN_TERMINAL, fapl_id) < 0)
@@ -3794,8 +3794,8 @@ test_ctl(void)
 
     TESTING_2("known op code to terminal VFD (with fail on unknown flag/route to terminal VFD)");
 
-    op_code = H5FD_CTL__TEST_OPCODE;
-    flags   = H5FD_CTL__FAIL_IF_UNKNOWN_FLAG | H5FD_CTL__ROUTE_TO_TERMINAL_VFD_FLAG;
+    op_code = H5FD_CTL_TEST_OPCODE;
+    flags   = H5FD_CTL_FAIL_IF_UNKNOWN_FLAG | H5FD_CTL_ROUTE_TO_TERMINAL_VFD_FLAG;
 
     /* H5FDctl call should succeed normally */
     if (run_ctl_test(op_code, flags, CTL_OPC_KNOWN_TERMINAL, fapl_id) < 0)
@@ -3817,7 +3817,7 @@ test_ctl(void)
     TESTING_2("unknown op code to terminal VFD (with fail on unknown flag)");
 
     op_code = H5FD_CTL_OPC_RESERVED;
-    flags   = H5FD_CTL__FAIL_IF_UNKNOWN_FLAG;
+    flags   = H5FD_CTL_FAIL_IF_UNKNOWN_FLAG;
 
     /* H5FDctl call should fail due to 'fail if unknown' flag being specified */
     if (run_ctl_test(op_code, flags, CTL_OPC_UNKNOWN, fapl_id) < 0)
@@ -3828,7 +3828,7 @@ test_ctl(void)
     TESTING_2("unknown op code to terminal VFD (without fail on unknown flag/route to terminal VFD)");
 
     op_code = H5FD_CTL_OPC_RESERVED;
-    flags   = H5FD_CTL__ROUTE_TO_TERMINAL_VFD_FLAG;
+    flags   = H5FD_CTL_ROUTE_TO_TERMINAL_VFD_FLAG;
 
     /* H5FDctl call should silently ignore unknown op code and succeed */
     if (run_ctl_test(op_code, flags, CTL_OPC_UNKNOWN, fapl_id) < 0)
@@ -3839,7 +3839,7 @@ test_ctl(void)
     TESTING_2("unknown op code to terminal VFD (with fail on unknown flag/route to terminal VFD)");
 
     op_code = H5FD_CTL_OPC_RESERVED;
-    flags   = H5FD_CTL__FAIL_IF_UNKNOWN_FLAG | H5FD_CTL__ROUTE_TO_TERMINAL_VFD_FLAG;
+    flags   = H5FD_CTL_FAIL_IF_UNKNOWN_FLAG | H5FD_CTL_ROUTE_TO_TERMINAL_VFD_FLAG;
 
     /* H5FDctl call should fail due to 'fail if unknown' flag being specified */
     if (run_ctl_test(op_code, flags, CTL_OPC_UNKNOWN, fapl_id) < 0)
@@ -3870,7 +3870,7 @@ test_ctl(void)
     TESTING_2("known op code through passthrough VFD to terminal VFD (without fail on unknown flag/no "
               "routing flag)");
 
-    op_code = H5FD_CTL__TEST_OPCODE;
+    op_code = H5FD_CTL_TEST_OPCODE;
     flags   = 0;
 
     /*
@@ -3886,8 +3886,8 @@ test_ctl(void)
     TESTING_2(
         "known op code through passthrough VFD to terminal VFD (with fail on unknown flag/no routing flag)");
 
-    op_code = H5FD_CTL__TEST_OPCODE;
-    flags   = H5FD_CTL__FAIL_IF_UNKNOWN_FLAG;
+    op_code = H5FD_CTL_TEST_OPCODE;
+    flags   = H5FD_CTL_FAIL_IF_UNKNOWN_FLAG;
 
     /*
      * H5FDctl call should fail since op code is unknown to
@@ -3903,8 +3903,8 @@ test_ctl(void)
     TESTING_2("known op code through passthrough VFD to terminal VFD (without fail on unknown flag/route to "
               "terminal VFD)");
 
-    op_code = H5FD_CTL__TEST_OPCODE;
-    flags   = H5FD_CTL__ROUTE_TO_TERMINAL_VFD_FLAG;
+    op_code = H5FD_CTL_TEST_OPCODE;
+    flags   = H5FD_CTL_ROUTE_TO_TERMINAL_VFD_FLAG;
 
     /*
      * H5Dctl call should succeed since the passthrough VFD
@@ -3919,8 +3919,8 @@ test_ctl(void)
     TESTING_2("known op code through passthrough VFD to terminal VFD (with fail on unknown flag/route to "
               "terminal VFD)");
 
-    op_code = H5FD_CTL__TEST_OPCODE;
-    flags   = H5FD_CTL__FAIL_IF_UNKNOWN_FLAG | H5FD_CTL__ROUTE_TO_TERMINAL_VFD_FLAG;
+    op_code = H5FD_CTL_TEST_OPCODE;
+    flags   = H5FD_CTL_FAIL_IF_UNKNOWN_FLAG | H5FD_CTL_ROUTE_TO_TERMINAL_VFD_FLAG;
 
     /*
      * H5Dctl call should succeed since the passthrough VFD
@@ -3950,7 +3950,7 @@ test_ctl(void)
     TESTING_2("unknown op code to passthrough VFD (with fail on unknown flag)");
 
     op_code = H5FD_CTL_OPC_RESERVED;
-    flags   = H5FD_CTL__FAIL_IF_UNKNOWN_FLAG;
+    flags   = H5FD_CTL_FAIL_IF_UNKNOWN_FLAG;
 
     /*
      * H5FDctl call should fail since op code is unknown to
@@ -3965,7 +3965,7 @@ test_ctl(void)
     TESTING_2("unknown op code to passthrough VFD (without fail on unknown flag/route to terminal VFD)");
 
     op_code = H5FD_CTL_OPC_RESERVED;
-    flags   = H5FD_CTL__ROUTE_TO_TERMINAL_VFD_FLAG;
+    flags   = H5FD_CTL_ROUTE_TO_TERMINAL_VFD_FLAG;
 
     /*
      * H5Dctl call should succeed since the passthrough VFD
@@ -3983,7 +3983,7 @@ test_ctl(void)
     TESTING_2("unknown op code to passthrough VFD (with fail on unknown flag/route to terminal VFD)");
 
     op_code = H5FD_CTL_OPC_RESERVED;
-    flags   = H5FD_CTL__FAIL_IF_UNKNOWN_FLAG | H5FD_CTL__ROUTE_TO_TERMINAL_VFD_FLAG;
+    flags   = H5FD_CTL_FAIL_IF_UNKNOWN_FLAG | H5FD_CTL_ROUTE_TO_TERMINAL_VFD_FLAG;
 
     /*
      * H5Dctl call should fail since the passthrough VFD
diff --git a/tools/lib/h5diff_array.c b/tools/lib/h5diff_array.c
index a7156b5..9fa3ccc 100644
--- a/tools/lib/h5diff_array.c
+++ b/tools/lib/h5diff_array.c
@@ -31,33 +31,29 @@
 #define UI_FORMAT   "%-15u %-15u %-15u\n"
 #define LI_FORMAT   "%-15ld %-15ld %-15ld\n"
 #define ULI_FORMAT  "%-15lu %-15lu %-15lu\n"
-#define LLI_FORMAT  "%-15" H5_PRINTF_LL_WIDTH "d %-15" H5_PRINTF_LL_WIDTH "d %-15" H5_PRINTF_LL_WIDTH "d\n"
-#define ULLI_FORMAT "%-15" H5_PRINTF_LL_WIDTH "u %-15" H5_PRINTF_LL_WIDTH "u %-15" H5_PRINTF_LL_WIDTH "u\n"
+#define LLI_FORMAT  "%-15lld %-15lld %-15lld\n"
+#define ULLI_FORMAT "%-15llu %-15llu %-15llu\n"
 
 /* with -p option */
-#define F_FORMAT_P   "%-15.10g %-15.10g %-15.10g %-14.10g\n"
-#define LD_FORMAT_P  "%-15.10Lg %-15.10Lg %-15.10Lg %-14.10Lg\n"
-#define I_FORMAT_P   "%-15d %-15d %-15d %-14f\n"
-#define UI_FORMAT_P  "%-15u %-15u %-15u %-14f\n"
-#define LI_FORMAT_P  "%-15ld %-15ld %-15ld %-14f\n"
-#define ULI_FORMAT_P "%-15lu %-15lu %-15lu %-14f\n"
-#define LLI_FORMAT_P                                                                                         \
-    "%-15" H5_PRINTF_LL_WIDTH "d %-15" H5_PRINTF_LL_WIDTH "d %-15" H5_PRINTF_LL_WIDTH "d %-14f\n"
-#define ULLI_FORMAT_P                                                                                        \
-    "%-15" H5_PRINTF_LL_WIDTH "u %-15" H5_PRINTF_LL_WIDTH "u %-15" H5_PRINTF_LL_WIDTH "d %-14f\n"
-#define SPACES "          "
+#define F_FORMAT_P    "%-15.10g %-15.10g %-15.10g %-14.10g\n"
+#define LD_FORMAT_P   "%-15.10Lg %-15.10Lg %-15.10Lg %-14.10Lg\n"
+#define I_FORMAT_P    "%-15d %-15d %-15d %-14f\n"
+#define UI_FORMAT_P   "%-15u %-15u %-15u %-14f\n"
+#define LI_FORMAT_P   "%-15ld %-15ld %-15ld %-14f\n"
+#define ULI_FORMAT_P  "%-15lu %-15lu %-15lu %-14f\n"
+#define LLI_FORMAT_P  "%-15lld %-15lld %-15lld %-14f\n"
+#define ULLI_FORMAT_P "%-15llu %-15llu %-15lld %-14f\n"
+#define SPACES        "          "
 
 /* not comparable */
-#define F_FORMAT_P_NOTCOMP   "%-15.10g %-15.10g %-15.10g not comparable\n"
-#define LD_FORMAT_P_NOTCOMP  "%-15.10Lg %-15.10Lg %-15.10Lg not comparable\n"
-#define I_FORMAT_P_NOTCOMP   "%-15d %-15d %-15d not comparable\n"
-#define UI_FORMAT_P_NOTCOMP  "%-15u %-15u %-15u not comparable\n"
-#define LI_FORMAT_P_NOTCOMP  "%-15ld %-15ld %-15ld not comparable\n"
-#define ULI_FORMAT_P_NOTCOMP "%-15lu %-15lu %-15lu not comparable\n"
-#define LLI_FORMAT_P_NOTCOMP                                                                                 \
-    "%-15" H5_PRINTF_LL_WIDTH "d %-15" H5_PRINTF_LL_WIDTH "d %-15" H5_PRINTF_LL_WIDTH "d not comparable\n"
-#define ULLI_FORMAT_P_NOTCOMP                                                                                \
-    "%-15" H5_PRINTF_LL_WIDTH "u %-15" H5_PRINTF_LL_WIDTH "u %-15" H5_PRINTF_LL_WIDTH "d not comparable\n"
+#define F_FORMAT_P_NOTCOMP    "%-15.10g %-15.10g %-15.10g not comparable\n"
+#define LD_FORMAT_P_NOTCOMP   "%-15.10Lg %-15.10Lg %-15.10Lg not comparable\n"
+#define I_FORMAT_P_NOTCOMP    "%-15d %-15d %-15d not comparable\n"
+#define UI_FORMAT_P_NOTCOMP   "%-15u %-15u %-15u not comparable\n"
+#define LI_FORMAT_P_NOTCOMP   "%-15ld %-15ld %-15ld not comparable\n"
+#define ULI_FORMAT_P_NOTCOMP  "%-15lu %-15lu %-15lu not comparable\n"
+#define LLI_FORMAT_P_NOTCOMP  "%-15lld %-15lld %-15lld not comparable\n"
+#define ULLI_FORMAT_P_NOTCOMP "%-15llu %-15llu %-15lld not comparable\n"
 
 /* if system EPSILON is defined, use the system EPSILON; otherwise, use
  constants that are close to most EPSILON values */
diff --git a/tools/lib/h5tools_str.c b/tools/lib/h5tools_str.c
index 5976044..5ade61f 100644
--- a/tools/lib/h5tools_str.c
+++ b/tools/lib/h5tools_str.c
@@ -660,8 +660,8 @@ h5tools_str_sprint(h5tools_str_t *str, const h5tool_format_t *info, hid_t contai
     H5TOOLS_START_DEBUG(" ");
     /* Build default formats for long long types */
     if (!fmt_llong[0]) {
-        HDsnprintf(fmt_llong, sizeof(fmt_llong), "%%%sd", H5_PRINTF_LL_WIDTH);
-        HDsnprintf(fmt_ullong, sizeof(fmt_ullong), "%%%su", H5_PRINTF_LL_WIDTH);
+        HDsnprintf(fmt_llong, sizeof(fmt_llong), "%%lld");
+        HDsnprintf(fmt_ullong, sizeof(fmt_ullong), "%%llu");
     }
 
     /* Append value depending on data type */
diff --git a/tools/src/h5perf/pio_engine.c b/tools/src/h5perf/pio_engine.c
index 1baaca2..9d08938 100644
--- a/tools/src/h5perf/pio_engine.c
+++ b/tools/src/h5perf/pio_engine.c
@@ -234,7 +234,7 @@ do_pio(parameters param)
     }
     if ((snbytes % pio_mpi_nprocs_g) != 0) {
         HDfprintf(stderr,
-                  "Dataset size (%" H5_PRINTF_LL_WIDTH "d) must be a multiple of the "
+                  "Dataset size (%lld) must be a multiple of the "
                   "number of processes (%d)\n",
                   (long long)snbytes, pio_mpi_nprocs_g);
         GOTOERROR(FAIL);
@@ -243,7 +243,7 @@ do_pio(parameters param)
     if (!param.dim2d) {
         if (((size_t)(snbytes / pio_mpi_nprocs_g) % buf_size) != 0) {
             HDfprintf(stderr,
-                      "Dataset size/process (%" H5_PRINTF_LL_WIDTH "d) must be a multiple of the "
+                      "Dataset size/process (%lld) must be a multiple of the "
                       "transfer buffer size (%zu)\n",
                       (long long)(snbytes / pio_mpi_nprocs_g), buf_size);
             GOTOERROR(FAIL);
@@ -252,7 +252,7 @@ do_pio(parameters param)
     else {
         if (((size_t)snbytes % buf_size) != 0) {
             HDfprintf(stderr,
-                      "Dataset side size (%" H5_PRINTF_LL_WIDTH "d) must be a multiple of the "
+                      "Dataset side size (%lld) must be a multiple of the "
                       "transfer buffer size (%zu)\n",
                       (long long)snbytes, buf_size);
             GOTOERROR(FAIL);
@@ -625,15 +625,13 @@ do_write(results *res, file_descr *fd, parameters *parms, long ndsets, off_t nby
         if (!parms->dim2d) {
             HDfprintf(output,
                       "Debug(do_write): "
-                      "buf_size=%zu, bytes_begin=%" H5_PRINTF_LL_WIDTH "d, bytes_count=%" H5_PRINTF_LL_WIDTH
-                      "d\n",
+                      "buf_size=%zu, bytes_begin=%lld, bytes_count=%lld\n",
                       buf_size, (long long)bytes_begin[0], (long long)bytes_count);
         }
         else {
             HDfprintf(output,
                       "Debug(do_write): "
-                      "linear buf_size=%zu, bytes_begin=(%" H5_PRINTF_LL_WIDTH "d,%" H5_PRINTF_LL_WIDTH
-                      "d), bytes_count=%" H5_PRINTF_LL_WIDTH "d\n",
+                      "linear buf_size=%zu, bytes_begin=(%lld,%lld), bytes_count=%lld\n",
                       buf_size * blk_size, (long long)bytes_begin[0], (long long)bytes_begin[1],
                       (long long)bytes_count);
         }
@@ -1640,15 +1638,13 @@ do_read(results *res, file_descr *fd, parameters *parms, long ndsets, off_t nbyt
         if (!parms->dim2d) {
             HDfprintf(output,
                       "Debug(do_write): "
-                      "buf_size=%zu, bytes_begin=%" H5_PRINTF_LL_WIDTH "d, bytes_count=%" H5_PRINTF_LL_WIDTH
-                      "d\n",
+                      "buf_size=%zu, bytes_begin=%lld, bytes_count=%lld\n",
                       buf_size, (long long)bytes_begin[0], (long long)bytes_count);
         }
         else {
             HDfprintf(output,
                       "Debug(do_write): "
-                      "linear buf_size=%zu, bytes_begin=(%" H5_PRINTF_LL_WIDTH "d,%" H5_PRINTF_LL_WIDTH
-                      "d), bytes_count=%" H5_PRINTF_LL_WIDTH "d\n",
+                      "linear buf_size=%zu, bytes_begin=(%lld,%lld), bytes_count=%lld\n",
                       buf_size * blk_size, (long long)bytes_begin[0], (long long)bytes_begin[1],
                       (long long)bytes_count);
         }
diff --git a/tools/src/h5perf/pio_perf.c b/tools/src/h5perf/pio_perf.c
index 003c4f2..7ebbefa 100644
--- a/tools/src/h5perf/pio_perf.c
+++ b/tools/src/h5perf/pio_perf.c
@@ -1121,25 +1121,25 @@ recover_size_and_print(long long val, const char *end)
         if (val >= ONE_MB && (val % ONE_MB) == 0) {
             if (val >= ONE_GB && (val % ONE_GB) == 0)
                 HDfprintf(output,
-                          "%" H5_PRINTF_LL_WIDTH "d"
+                          "%lld"
                           "GB%s",
                           val / ONE_GB, end);
             else
                 HDfprintf(output,
-                          "%" H5_PRINTF_LL_WIDTH "d"
+                          "%lld"
                           "MB%s",
                           val / ONE_MB, end);
         }
         else {
             HDfprintf(output,
-                      "%" H5_PRINTF_LL_WIDTH "d"
+                      "%lld"
                       "KB%s",
                       val / ONE_KB, end);
         }
     }
     else {
         HDfprintf(output,
-                  "%" H5_PRINTF_LL_WIDTH "d"
+                  "%lld"
                   "%s",
                   val, end);
     }
diff --git a/tools/src/h5perf/sio_engine.c b/tools/src/h5perf/sio_engine.c
index abf8b9a..c12e1da 100644
--- a/tools/src/h5perf/sio_engine.c
+++ b/tools/src/h5perf/sio_engine.c
@@ -179,7 +179,7 @@ do_sio(parameters param, results *res)
 
         if ((param.dset_size[i] % param.buf_size[i]) != 0) {
             HDfprintf(stderr,
-                      "Dataset size[%d] (%" H5_PRINTF_LL_WIDTH "d) must be a multiple of the "
+                      "Dataset size[%d] (%lld) must be a multiple of the "
                       "transfer buffer size[%d] (%zu)\n",
                       param.rank, (long long)param.dset_size[i], param.rank, param.buf_size[i]);
             GOTOERROR(FAIL);
diff --git a/tools/src/h5perf/sio_perf.c b/tools/src/h5perf/sio_perf.c
index dc2e15e..5432d6c 100644
--- a/tools/src/h5perf/sio_perf.c
+++ b/tools/src/h5perf/sio_perf.c
@@ -674,25 +674,25 @@ recover_size_and_print(long long val, const char *end)
         if (val >= ONE_MB && (val % ONE_MB) == 0) {
             if (val >= ONE_GB && (val % ONE_GB) == 0)
                 HDfprintf(output,
-                          "%" H5_PRINTF_LL_WIDTH "d"
+                          "%lld"
                           "GB%s",
                           val / ONE_GB, end);
             else
                 HDfprintf(output,
-                          "%" H5_PRINTF_LL_WIDTH "d"
+                          "%lld"
                           "MB%s",
                           val / ONE_MB, end);
         }
         else {
             HDfprintf(output,
-                      "%" H5_PRINTF_LL_WIDTH "d"
+                      "%lld"
                       "KB%s",
                       val / ONE_KB, end);
         }
     }
     else {
         HDfprintf(output,
-                  "%" H5_PRINTF_LL_WIDTH "d"
+                  "%lld"
                   "%s",
                   val, end);
     }