Merge pull request #1764 in HDFFV/hdf5 from ~KOZIOL/hdf5:feature/update_gcc_flags to develop

Updated CMake bulids, too.

* commit '17ae90917856e4cbab5a2f1c597197ee98802fc7':
  Update GCC 6 & 7 flags for CMake builds
  Move -Wnormalized down into GCC 6.x flags
  Add support for GCC 7.x warnings, update warnhist script to account for them, clean up warnings.

61 files changed, 278 insertions, 175 deletions

diff --git a/bin/warnhist b/bin/warnhist
index 6b7ef73..5750c77 100755
--- a/bin/warnhist
+++ b/bin/warnhist
@@ -155,6 +155,7 @@ while (<>) {
     my $toss;
     my $offset;
     my $warning;
+    my $extra;
 
     # Retain last FORTRAN compile line, which comes a few lines before warning
     if($_ =~ /.*\.[fF]90:.*/) {
@@ -176,12 +177,12 @@ while (<>) {
     if($_ =~ /^cc1: warning:.*/) {
         $name = $last_c_name;
         $line = "??";
-        ($toss, $toss, $warning) = split /\:/, $_;
+        ($toss, $toss, $warning, $extra) = split /\:/, $_;
     # Check for FORTRAN warning output
     } elsif($_ =~ /^Warning:.*/) {
         $name = $last_fort_name;
         $line = $last_fort_line;
-        ($toss, $warning) = split /\:/, $_;
+        ($toss, $warning, $extra) = split /\:/, $_;
 #print "1:",$.,":",$_;
 #        $_ = <>;
 #print "2:",$.,":",$_;
@@ -203,12 +204,19 @@ while (<>) {
     } else {
         # Check for 'character offset' field
         if($_ =~ /^.*[0-9]+\:[0-9]+\:/) {
-            ($name, $line, $offset, $toss, $warning) = split /\:/, $_;
+            ($name, $line, $offset, $toss, $warning, $extra) = split /\:/, $_;
         } else {
-            ($name, $line, $toss, $warning) = split /\:/, $_;
+            ($name, $line, $toss, $warning, $extra) = split /\:/, $_;
         }
     }
 
+    # Check for extra ':' followed by more text in original warning string,
+    #  and append the ':' and text back onto the parsed warning
+    #  (Use 'length $extra' idiom to avoid warning when $extra is undefined)
+    if(length $extra ) {
+        $warning = join ':', $warning, $extra;
+    }
+
     # Trim leading '..' paths from filename
     while($name =~ /^\.\.\//) {
         $name =~ s/^\.\.\///g;
@@ -401,6 +409,28 @@ while (<>) {
     } elsif($warning =~ /function might be candidate for attribute '[A-Za-z_0-9]*' \[-Wsuggest-attribute=[A-Za-z_0-9]*\].*/) {
         $warning =~ s/'[A-Za-z_0-9]*'/'-'/g;
         $warning =~ s/=[A-Za-z_0-9]*\]/=-\]/g;
+    } elsif($warning =~ /passing argument [0-9]+ of '[A-Za-z_0-9]*' makes integer from pointer without a cast \[-Wint-conversion\].*/) {
+        $warning =~ s/'[A-Za-z_0-9]*'/'-'/g;
+        $warning =~ s/[0-9]+/-/g;
+    } elsif($warning =~ /function '[A-Za-z_0-9]*' might be a candidate for '[A-Za-z_0-9]*' format attribute \[-Wsuggest-attribute=format\].*/) {
+        $warning =~ s/'[A-Za-z_0-9]*'/'-'/g;
+    } elsif($warning =~ /inlining failed in call to '[A-Za-z_0-9]*': call is unlikely and code size would grow \[-Winline\].*/) {
+        $warning =~ s/'[A-Za-z_0-9]*'/'-'/g;
+    } elsif($warning =~ /'%[0-9]*[\.\*]*[0-9]*[dfsu]' directive writing between [0-9]+ and [0-9]+ bytes into a region of size [0-9]+ \[-Wformat-overflow=\].*/) {
+        $warning =~ s/'%[0-9]*[\.\*]*[0-9]*[dfsu]'/'-'/g;
+        $warning =~ s/[0-9]+/-/g;
+    } elsif($warning =~ /'%[0-9]*[\.\*]*[0-9]*[dfsu]' directive writing between [0-9]+ and [0-9]+ bytes into a region of size between [0-9]+ and [0-9]+ \[-Wformat-overflow=\].*/) {
+        $warning =~ s/'%[0-9]*[\.\*]*[0-9]*[dfsu]'/'-'/g;
+        $warning =~ s/[0-9]+/-/g;
+    } elsif($warning =~ /'%[0-9]*[\.\*]*[0-9]*[dfsu]' directive output may be truncated writing between [0-9]+ and [0-9]+ bytes into a region of size [0-9]+ \[-Wformat-truncation=\].*/) {
+        $warning =~ s/'%[0-9]*[\.\*]*[0-9]*[dfsu]'/'-'/g;
+        $warning =~ s/[0-9]+/-/g;
+    } elsif($warning =~ /'%[0-9]*[\.\*]*[0-9]*[dfsu]' directive output may be truncated writing up to [0-9]+ bytes into a region of size [0-9]+ \[-Wformat-truncation=\].*/) {
+        $warning =~ s/'%[0-9]*[\.\*]*[0-9]*[dfsu]'/'-'/g;
+        $warning =~ s/[0-9]+/-/g;
+    } elsif($warning =~ /'%[0-9]*[\.\*]*[0-9]*[dfsu]' directive output may be truncated writing between [0-9]+ and [0-9]+ bytes into a region of size between [0-9]+ and [0-9]+ \[-Wformat-truncation=\].*/) {
+        $warning =~ s/'%[0-9]*[\.\*]*[0-9]*[dfsu]'/'-'/g;
+        $warning =~ s/[0-9]+/-/g;
     }
 
     # Increment count for [generic] warning
diff --git a/config/cmake/HDFCompilerFlags.cmake b/config/cmake/HDFCompilerFlags.cmake
index 0a39568..4712f50 100644
--- a/config/cmake/HDFCompilerFlags.cmake
+++ b/config/cmake/HDFCompilerFlags.cmake
@@ -195,7 +195,12 @@ if (NOT MSVC AND CMAKE_COMPILER_IS_GNUCC)
 
     # Append more extra warning flags that only gcc 6.x+ know about
     if (CMAKE_C_COMPILER_ID STREQUAL "GNU" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 6.0)
-      set (H5_CFLAGS4 "${H5_CFLAGS4} -Wnull-dereference -Wunused-const-variable -Wduplicated-cond -Whsa")
+      set (H5_CFLAGS4 "${H5_CFLAGS4} -Wnull-dereference -Wunused-const-variable -Wduplicated-cond -Whsa -Wnormalized")
+    endif ()
+
+    # Append more extra warning flags that only gcc 7.x+ know about
+    if (CMAKE_C_COMPILER_ID STREQUAL "GNU" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 7.0)
+      set (H5_CFLAGS4 "${H5_CFLAGS4} -Walloc-zero -Walloca -Wduplicated-branches -Wformat-overflow=2 -Wformat-truncation=2 -Wimplicit-fallthrough=5 -Wrestrict")
     endif ()
 
 endif ()
diff --git a/config/gnu-flags b/config/gnu-flags
index 7df72c7..c55391d 100644
--- a/config/gnu-flags
+++ b/config/gnu-flags
@@ -117,7 +117,7 @@ case "$cc_vendor-$cc_version" in
     H5_CFLAGS="$H5_CFLAGS -Wcast-qual -Wconversion -Wdeclaration-after-statement -Wdisabled-optimization -Wfloat-equal"
     H5_CFLAGS="$H5_CFLAGS -Wformat=2 -Winit-self -Winvalid-pch -Wmissing-declarations -Wmissing-include-dirs"
     H5_CFLAGS="$H5_CFLAGS -Wmissing-prototypes -Wnested-externs -Wold-style-definition -Wpacked -Wpointer-arith"
-    H5_CFLAGS="$H5_CFLAGS -Wredundant-decls -Wshadow -Wstrict-prototypes -Wswitch-default -Wswitch-enum"
+    H5_CFLAGS="$H5_CFLAGS -Wredundant-decls -Wshadow -Wstrict-prototypes -Wswitch-enum -Wswitch-default"
     H5_CFLAGS="$H5_CFLAGS -Wundef -Wunused-macros -Wunsafe-loop-optimizations -Wwrite-strings"
 
     # Production
@@ -187,10 +187,10 @@ esac
 # the information from the previous version and adding modifications to that.
 case "$cc_vendor-$cc_version" in
 
-# When the gcc 7.x release is out, we should check for additional flags to
+# When the gcc 8.x release is out, we should check for additional flags to
 # include and break it out into it's own section, like the other versions
 # below. -QAK
-  gcc-[6789].*)
+  gcc-[789].*)
     # Append warning flags that only gcc 4.2+ knows about
     # (none, or incorporated in -Wall / -Wextra now)
 
@@ -227,7 +227,51 @@ case "$cc_vendor-$cc_version" in
     H5_CFLAGS="$H5_CFLAGS -Warray-bounds=2 -Wc99-c11-compat"
 
     # Append warning flags that only gcc 6.x+ knows about
-    H5_CFLAGS="$H5_CFLAGS -Wnull-dereference -Wunused-const-variable -Wduplicated-cond -Whsa"
+    H5_CFLAGS="$H5_CFLAGS -Wnull-dereference -Wunused-const-variable -Wduplicated-cond -Whsa -Wnormalized"
+
+    # Append warning flags that only gcc 7.x+ knows about
+    DEVELOPER_WARNING_CFLAGS="$DEVELOPER_WARNING_CFLAGS -Wstringop-overflow=2"
+    H5_CFLAGS="$H5_CFLAGS -Walloc-zero -Walloca -Wduplicated-branches -Wformat-overflow=2 -Wformat-truncation=2 -Wimplicit-fallthrough=5 -Wrestrict"
+    ;;
+
+  gcc-6*)
+    # Append warning flags that only gcc 4.2+ knows about
+    # (none, or incorporated in -Wall / -Wextra now)
+
+    # Append warning flags that only gcc 4.3+ knows about
+    #
+    # Technically, variable-length arrays are part of the C99 standard, but
+    #   we should approach them a bit cautiously... -QAK
+    H5_CFLAGS="$H5_CFLAGS -Wlogical-op -Wlarger-than=2048 -Wvla"
+
+    # Append warning flags that only gcc 4.4+ knows about
+    H5_CFLAGS="$H5_CFLAGS -Wsync-nand -Wframe-larger-than=16384 -Wpacked-bitfield-compat"
+
+    # Append warning flags that only gcc 4.5+ knows about
+    H5_CFLAGS="$H5_CFLAGS -Wstrict-overflow=5 -Wjump-misses-init -Wunsuffixed-float-constants"
+
+    # Append warning flags that only gcc 4.6+ knows about
+    H5_CFLAGS="$H5_CFLAGS -Wdouble-promotion -Wtrampolines"
+    DEVELOPER_WARNING_CFLAGS="$DEVELOPER_WARNING_CFLAGS -Wsuggest-attribute=const"
+    NO_DEVELOPER_WARNING_CFLAGS="$NO_DEVELOPER_WARNING_CFLAGS -Wno-suggest-attribute=const"
+
+    # Append warning flags that only gcc 4.7+ knows about
+    H5_CFLAGS="$H5_CFLAGS -Wstack-usage=8192 -Wvector-operation-performance"
+    DEVELOPER_WARNING_CFLAGS="$DEVELOPER_WARNING_CFLAGS -Wsuggest-attribute=pure -Wsuggest-attribute=noreturn"
+    NO_DEVELOPER_WARNING_CFLAGS="$NO_DEVELOPER_WARNING_CFLAGS -Wno-suggest-attribute=pure -Wno-suggest-attribute=noreturn"
+
+    # Append warning flags that only gcc 4.8+ knows about
+    DEVELOPER_WARNING_CFLAGS="$DEVELOPER_WARNING_CFLAGS -Wsuggest-attribute=format"
+    NO_DEVELOPER_WARNING_CFLAGS="$NO_DEVELOPER_WARNING_CFLAGS -Wno-suggest-attribute=format"
+
+    # Append warning flags that only gcc 4.9+ knows about
+    H5_CFLAGS="$H5_CFLAGS -Wdate-time"
+
+    # Append warning flags that only gcc 5.x+ knows about
+    H5_CFLAGS="$H5_CFLAGS -Warray-bounds=2 -Wc99-c11-compat"
+
+    # Append warning flags that only gcc 6.x+ knows about
+    H5_CFLAGS="$H5_CFLAGS -Wnull-dereference -Wunused-const-variable -Wduplicated-cond -Whsa -Wnormalized"
     ;;
 
   gcc-5*)
diff --git a/fortran/src/H5Fff.F90 b/fortran/src/H5Fff.F90
index ac3a1c0..8574c06 100644
--- a/fortran/src/H5Fff.F90
+++ b/fortran/src/H5Fff.F90
@@ -591,7 +591,6 @@ CONTAINS
                                            ! is an HDF5 file
     INTEGER, INTENT(OUT) :: hdferr         ! Error code
 !*****
-    INTEGER(HID_T) :: access_prp_default
     CHARACTER(LEN=LEN_TRIM(name)+1,KIND=C_CHAR) :: c_name
     INTEGER(C_INT) :: flag    ! "TRUE/FALSE/ERROR" flag from C routine
                               ! to define status value.
diff --git a/fortran/src/H5VLff.F90 b/fortran/src/H5VLff.F90
index 9abc157..e21f38f 100644
--- a/fortran/src/H5VLff.F90
+++ b/fortran/src/H5VLff.F90
@@ -217,7 +217,6 @@ CONTAINS
 !*****
     CHARACTER(LEN=1,KIND=C_CHAR), DIMENSION(1:LEN(name)+1), TARGET :: c_name
     INTEGER(SIZE_T) :: l
-    TYPE(C_PTR) :: f_ptr
 
     INTERFACE
        INTEGER(SIZE_T) FUNCTION H5VLget_connector_name(obj_id, name, size) BIND(C,NAME='H5VLget_connector_name')
diff --git a/fortran/test/tH5O_F03.F90 b/fortran/test/tH5O_F03.F90
index d1a9ddb..78b6453 100644
--- a/fortran/test/tH5O_F03.F90
+++ b/fortran/test/tH5O_F03.F90
@@ -270,8 +270,6 @@ CONTAINS
 ! A(8) = tm_yday  int   days since January 1       0-365
 ! A(9) = tm_isdst int   Daylight Saving Time flag
 !
-    INTEGER(C_INT), DIMENSION(:), POINTER :: c_atime, c_btime, c_ctime, c_mtime
-    INTEGER(C_INT), DIMENSION(1:8) :: atime, btime, ctime, mtime
     INTEGER :: len, i
     INTEGER :: idx
     INTEGER :: ierr
diff --git a/hl/fortran/src/H5TBff.F90 b/hl/fortran/src/H5TBff.F90
index d18d023..40adf95 100644
--- a/hl/fortran/src/H5TBff.F90
+++ b/hl/fortran/src/H5TBff.F90
@@ -939,10 +939,10 @@ CONTAINS
     INTEGER(size_t),  DIMENSION(nfields), INTENT(inout) :: field_offsets  ! field offsets
     INTEGER(size_t),  INTENT(inout):: type_size                           ! type size
     INTEGER :: errcode                                                    ! error code
-    INTEGER, OPTIONAL :: maxlen_out                                       ! maximum character len of the field names
+    INTEGER(size_t), OPTIONAL :: maxlen_out                               ! maximum character len of the field names
     INTEGER(size_t) :: namelen                                            ! name length
     INTEGER(size_t), DIMENSION(nfields) :: namelen2                       ! name lengths
-    INTEGER(hsize_t) :: i                                                          ! general purpose integer
+    INTEGER(hsize_t) :: i                                                 ! general purpose integer
     INTEGER(size_t) :: maxlen
     INTEGER(size_t) :: c_maxlen_out
     
diff --git a/hl/fortran/test/tstimage.F90 b/hl/fortran/test/tstimage.F90
index d6bd1e2..8586e68 100644
--- a/hl/fortran/test/tstimage.F90
+++ b/hl/fortran/test/tstimage.F90
@@ -62,7 +62,7 @@ character(len=4), parameter :: dsetname2 = "img2"    ! dataset name
 character(len=15), parameter :: il ="INTERLACE_PIXEL"! dataset name
 integer(hid_t) :: file_id                            ! file identifier
 integer(hsize_t), parameter :: width  = 500          ! width of image
-integer(hsize_t), parameter :: height = 200          ! height of image
+integer(hsize_t), parameter :: height = 270          ! height of image
 integer, parameter :: pal_entries = 9                ! palette number of entries
 integer, dimension(width*height) :: buf1             ! data buffer
 integer, dimension(width*height) :: bufr1            ! data buffer
diff --git a/hl/fortran/test/tsttable.F90 b/hl/fortran/test/tsttable.F90
index 38cfa86..840d33d 100644
--- a/hl/fortran/test/tsttable.F90
+++ b/hl/fortran/test/tsttable.F90
@@ -93,7 +93,7 @@ SUBROUTINE test_table1()
   INTEGER(SIZE_T),  DIMENSION(1:nfields) :: field_offsetr ! field offset
   INTEGER(SIZE_T),  DIMENSION(1:nfields) :: field_sizesr  ! field sizes
   INTEGER(SIZE_T)  :: type_sizeout = 0                    ! size of the datatype
-  INTEGER :: maxlen = 0                                   ! max chararter length of a field name
+  INTEGER(SIZE_T)  :: maxlen = 0                          ! max character length of a field name
   INTEGER :: Cs_sizeof_double = H5_SIZEOF_DOUBLE          ! C's sizeof double
   INTEGER :: SIZEOF_X
   LOGICAL :: Exclude_double
diff --git a/hl/src/H5LT.c b/hl/src/H5LT.c
index 0074d02..3ebca95 100644
--- a/hl/src/H5LT.c
+++ b/hl/src/H5LT.c
@@ -2264,7 +2264,7 @@ out:
 *-------------------------------------------------------------------------
 */
 static char* 
-realloc_and_append(hbool_t _no_user_buf, size_t *len, char *buf, char *str_to_add)
+realloc_and_append(hbool_t _no_user_buf, size_t *len, char *buf, const char *str_to_add)
 {
     size_t size_str_to_add, size_str;
 
@@ -2360,7 +2360,6 @@ print_enum(hid_t type, char* str, size_t *str_len, hbool_t no_ubuf, size_t indt)
 {
     char           **name = NULL;   /*member names                   */
     unsigned char   *value = NULL;  /*value array                    */
-    unsigned char   *copy = NULL;   /*a pointer to value array       */
     int              nmembs;        /*number of members              */
     char             tmp_str[TMP_LEN];
     int              nchars;        /*number of output characters    */
@@ -2418,17 +2417,15 @@ print_enum(hid_t type, char* str, size_t *str_len, hbool_t no_ubuf, size_t indt)
         nchars = HDsnprintf(tmp_str, TMP_LEN, "\"%s\"", name[i]);
         if(!(str = realloc_and_append(no_ubuf, str_len, str, tmp_str)))
             goto out;
-        HDsnprintf(tmp_str, TMP_LEN, "%*s   ", MAX(0, 16 - nchars), "");
+        HDmemset(tmp_str, ' ', (size_t)MAX(3, 19 - nchars) + 1);
+        tmp_str[MAX(3, 19 - nchars)] = '\0';
         if(!(str = realloc_and_append(no_ubuf, str_len, str, tmp_str)))
             goto out;
 
-        /*On SGI Altix(cobalt), wrong values were printed out with "value+i*dst_size"
-         *strangely, unless use another pointer "copy".*/
-        copy = value + (size_t)i * dst_size;
         if (H5T_SGN_NONE == H5Tget_sign(native))
-            HDsnprintf(tmp_str, TMP_LEN, "%u", *((unsigned int*)((void *)copy)));
+            HDsnprintf(tmp_str, TMP_LEN, "%u", *((unsigned int*)(value + (size_t)i * dst_size)));
         else
-            HDsnprintf(tmp_str, TMP_LEN, "%d", *((int*)((void *)copy)));
+            HDsnprintf(tmp_str, TMP_LEN, "%d", *((int*)(value + (size_t)i * dst_size)));
         if(!(str = realloc_and_append(no_ubuf, str_len, str, tmp_str)))
             goto out;
 
@@ -2450,8 +2447,12 @@ print_enum(hid_t type, char* str, size_t *str_len, hbool_t no_ubuf, size_t indt)
 out:
 
     if(0 == nmembs) {
-        HDsnprintf(tmp_str, TMP_LEN, "\n%*s <empty>", (int)(indt + 4), "");
+        str = realloc_and_append(no_ubuf, str_len, str, "\n");
+        HDassert((indt + 4) < TMP_LEN);
+        HDmemset(tmp_str, ' ', (indt + 4) + 1);
+        tmp_str[(indt + 4)] = '\0';
         str = realloc_and_append(no_ubuf, str_len, str, tmp_str);
+        str = realloc_and_append(no_ubuf, str_len, str, " <empty>");
     } /* end if */
 
     /* Release resources */
diff --git a/hl/test/test_ds.c b/hl/test/test_ds.c
index 95178fc..d7af9e9 100644
--- a/hl/test/test_ds.c
+++ b/hl/test/test_ds.c
@@ -1138,7 +1138,7 @@ static int test_detachscales(void)
     int     rank3 = 3;
     hsize_t dims[] = {1,2,3}; /*some bogus numbers, not important for the test*/
     int     *buf = NULL;
-    char    dname[10];
+    char    dname[16];
     int     i;
 
     /* This tests creates two three dimensional datasets; then it creates
diff --git a/src/H5Clog_trace.c b/src/H5Clog_trace.c
index 7c1305c..713f333 100644
--- a/src/H5Clog_trace.c
+++ b/src/H5Clog_trace.c
@@ -41,7 +41,7 @@
 /****************/
 
 /* Max log message size */
-#define H5C_MAX_TRACE_LOG_MSG_SIZE 2048
+#define H5C_MAX_TRACE_LOG_MSG_SIZE 4096
 
 
 /******************/
diff --git a/src/H5Dint.c b/src/H5Dint.c
index 220f026..63d1160 100644
--- a/src/H5Dint.c
+++ b/src/H5Dint.c
@@ -1095,7 +1095,6 @@ H5D__build_file_prefix(const H5D_t *dset, H5F_prefix_open_t prefix_type, char **
     size_t          filepath_len;         /* length of file path                            */
     size_t          prefix_len;           /* length of prefix                               */
     size_t          file_prefix_len;      /* length of expanded prefix                      */
-    H5P_genplist_t  *plist = NULL;        /* Property list pointer                          */
     herr_t          ret_value = SUCCEED;  /* Return value                                   */
 
     FUNC_ENTER_STATIC
diff --git a/src/H5Fint.c b/src/H5Fint.c
index ee9afed..030fda8 100644
--- a/src/H5Fint.c
+++ b/src/H5Fint.c
@@ -509,6 +509,7 @@ H5F__get_objects_cb(void *obj_ptr, hid_t obj_id, void *key)
             case H5I_ERROR_CLASS:
             case H5I_ERROR_MSG:
             case H5I_ERROR_STACK:
+            case H5I_SPACE_SEL_ITER:
             case H5I_NTYPES:
             default:
                 HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5_ITER_ERROR, "unknown or invalid data object")
@@ -3610,6 +3611,7 @@ H5F__get_file(void *obj, H5I_type_t type)
         case H5I_ERROR_CLASS:
         case H5I_ERROR_MSG:
         case H5I_ERROR_STACK:
+        case H5I_SPACE_SEL_ITER:
         case H5I_NTYPES:
         default:
             HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "not a file or file object")
diff --git a/src/H5Fprivate.h b/src/H5Fprivate.h
index 0fa2214..e9b6c32 100644
--- a/src/H5Fprivate.h
+++ b/src/H5Fprivate.h
@@ -160,16 +160,16 @@ typedef struct H5F_t H5F_t;
    (i) |= (uint16_t)((*(p) & 0xff) << 8); (p)++;                  \
 }
 
-#  define INT32DECODE(p, i) {                              \
-   (i)    = ((int32_t)(*(p) & (unsigned)0xff));      (p)++;              \
-   (i) |= ((int32_t)(*(p) & (unsigned)0xff) <<  8); (p)++;              \
-   (i) |= ((int32_t)(*(p) & (unsigned)0xff) << 16); (p)++;              \
-   (i) |= ((int32_t)(((*(p) & (unsigned)0xff) << 24) |                        \
-                   ((*(p) & (unsigned)0x80) ? (unsigned)(~0xffffffff) : (unsigned)0x0))); (p)++; \
+#  define INT32DECODE(p, i) {                                \
+   (i)  = ((int32_t)(*(p) & 0xff));      (p)++;              \
+   (i) |= ((int32_t)(*(p) & 0xff) <<  8); (p)++;             \
+   (i) |= ((int32_t)(*(p) & 0xff) << 16); (p)++;             \
+   (i) |= ((int32_t)(((*(p) & (unsigned)0xff) << 24) |                 \
+            ((*(p) & 0x80) ? ~0xffffffffULL : 0x0ULL))); (p)++;    \
 }
 
-#  define UINT32DECODE(p, i) {                              \
-   (i)    =  (uint32_t)(*(p) & 0xff);       (p)++;                  \
+#  define UINT32DECODE(p, i) {                                     \
+   (i)  =  (uint32_t)(*(p) & 0xff);       (p)++;                   \
    (i) |= ((uint32_t)(*(p) & 0xff) <<  8); (p)++;                  \
    (i) |= ((uint32_t)(*(p) & 0xff) << 16); (p)++;                  \
    (i) |= ((uint32_t)(*(p) & 0xff) << 24); (p)++;                  \
diff --git a/src/H5Fsuper.c b/src/H5Fsuper.c
index aa5a85d..ef52844 100644
--- a/src/H5Fsuper.c
+++ b/src/H5Fsuper.c
@@ -513,15 +513,12 @@ H5F__super_read(H5F_t *f, H5P_genplist_t *fa_plist, hbool_t initial_read)
 #endif /* H5_HAVE_PARALLEL */
 
     /* Check if superblock address is different from base address and adjust
-     * base address and "end of address" address if so.
+     * base address and "end of file" address if so.
      */
     if(!H5F_addr_eq(super_addr, sblock->base_addr)) {
-        /* Check if the superblock moved earlier in the file */
-        if(H5F_addr_lt(super_addr, sblock->base_addr))
-            udata.stored_eof -= (sblock->base_addr - super_addr);
-        else
-            /* The superblock moved later in the file */
-            udata.stored_eof += (super_addr - sblock->base_addr);
+        /* If the superblock moved in the file, adjust the EOF */
+        /* (Handles moving earlier & later) */
+        udata.stored_eof -= (sblock->base_addr - super_addr);
 
         /* Adjust base address for offsets of the HDF5 data in the file */
         sblock->base_addr = super_addr;
diff --git a/src/H5Gloc.c b/src/H5Gloc.c
index 5724031..e47d3be 100644
--- a/src/H5Gloc.c
+++ b/src/H5Gloc.c
@@ -226,7 +226,10 @@ H5G_loc_real(void *obj, H5I_type_t type, H5G_loc_t *loc)
             HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "unable to get group location of a virtual file driver (VFD)")
 
         case H5I_VOL:
-            HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "unable to get group location of a virtual object layer (VOL) driver")
+            HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "unable to get group location of a virtual object layer (VOL) connector")
+
+        case H5I_SPACE_SEL_ITER:
+            HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "unable to get group location of a dataspace selection iterator")
 
         case H5I_UNINIT:
         case H5I_BADID:
diff --git a/src/H5Gname.c b/src/H5Gname.c
index fa0a925..16c1ca7 100644
--- a/src/H5Gname.c
+++ b/src/H5Gname.c
@@ -828,6 +828,7 @@ H5G_name_replace_cb(void *obj_ptr, hid_t obj_id, void *key)
         case H5I_ERROR_CLASS:
         case H5I_ERROR_MSG:
         case H5I_ERROR_STACK:
+        case H5I_SPACE_SEL_ITER:
         case H5I_NTYPES:
         default:
             HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "unknown data object")
diff --git a/src/H5Gtest.c b/src/H5Gtest.c
index af6acb3..0b431b1 100644
--- a/src/H5Gtest.c
+++ b/src/H5Gtest.c
@@ -616,6 +616,7 @@ H5G__user_path_test(hid_t obj_id, char *user_path, size_t *user_path_len, unsign
         case H5I_ERROR_CLASS:
         case H5I_ERROR_MSG:
         case H5I_ERROR_STACK:
+        case H5I_SPACE_SEL_ITER:
         case H5I_NTYPES:
         default:
             HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "unknown data object type")
diff --git a/src/H5I.c b/src/H5I.c
index 87ff04a..cdc849b 100644
--- a/src/H5I.c
+++ b/src/H5I.c
@@ -2171,7 +2171,6 @@ H5Iget_name(hid_t id, char *name/*out*/, size_t size)
 {
     H5VL_object_t *vol_obj;     /* Object token of loc_id */
     H5VL_loc_params_t loc_params;
-    H5G_loc_t     loc;          /* Object location */
     ssize_t       ret_value;    /* Return value */
 
     FUNC_ENTER_API((-1))
@@ -2384,6 +2383,7 @@ H5I__id_dump_cb(void *_item, void H5_ATTR_UNUSED *_key, void *_udata)
         case H5I_ERROR_CLASS:
         case H5I_ERROR_MSG:
         case H5I_ERROR_STACK:
+        case H5I_SPACE_SEL_ITER:
         case H5I_NTYPES:
         default:
             break;   /* Other types of IDs are not stored in files */
diff --git a/src/H5O.c b/src/H5O.c
index 0fdb9be..093d429 100644
--- a/src/H5O.c
+++ b/src/H5O.c
@@ -1102,6 +1102,7 @@ H5Oclose(hid_t object_id)
         case H5I_ERROR_CLASS:
         case H5I_ERROR_MSG:
         case H5I_ERROR_STACK:
+        case H5I_SPACE_SEL_ITER:
         case H5I_NTYPES:
         default:
             HGOTO_ERROR(H5E_ARGS, H5E_CANTRELEASE, FAIL, "not a valid file object ID (dataset, group, or datatype)")
diff --git a/src/H5Oflush.c b/src/H5Oflush.c
index da9d1d0..f5ede4a 100644
--- a/src/H5Oflush.c
+++ b/src/H5Oflush.c
@@ -491,6 +491,7 @@ H5O_refresh_metadata_reopen(hid_t oid, H5G_loc_t *obj_loc, H5VL_t *vol_connector
         case H5I_ERROR_CLASS:
         case H5I_ERROR_MSG:
         case H5I_ERROR_STACK:
+        case H5I_SPACE_SEL_ITER:
         case H5I_NTYPES:
         default:
             HGOTO_ERROR(H5E_OHDR, H5E_BADTYPE, FAIL, "not a valid file object ID (dataset, group, or datatype)")
diff --git a/src/H5Oint.c b/src/H5Oint.c
index 60aae45..45a8046 100644
--- a/src/H5Oint.c
+++ b/src/H5Oint.c
@@ -1848,6 +1848,7 @@ H5O_get_loc(hid_t object_id)
         case H5I_ERROR_CLASS:
         case H5I_ERROR_MSG:
         case H5I_ERROR_STACK:
+        case H5I_SPACE_SEL_ITER:
         case H5I_NTYPES:
         default:
             HGOTO_ERROR(H5E_OHDR, H5E_BADTYPE, NULL, "invalid object type")
diff --git a/src/H5Opkg.h b/src/H5Opkg.h
index 668f4f0..4afa452 100644
--- a/src/H5Opkg.h
+++ b/src/H5Opkg.h
@@ -134,9 +134,9 @@
                 ) : 0))							      \
     )
 #define H5O_SIZEOF_MSGHDR_OH(O)						      \
-    H5O_SIZEOF_MSGHDR_VERS((O)->version, (O)->flags & H5O_HDR_ATTR_CRT_ORDER_TRACKED)
+    (unsigned)H5O_SIZEOF_MSGHDR_VERS((O)->version, (O)->flags & H5O_HDR_ATTR_CRT_ORDER_TRACKED)
 #define H5O_SIZEOF_MSGHDR_F(F, C)						      \
-    H5O_SIZEOF_MSGHDR_VERS(MAX((H5F_STORE_MSG_CRT_IDX(F) ? H5O_VERSION_LATEST : H5O_VERSION_1), (uint8_t)H5O_obj_ver_bounds[H5F_LOW_BOUND(F)]), (C))
+    (unsigned)H5O_SIZEOF_MSGHDR_VERS(MAX((H5F_STORE_MSG_CRT_IDX(F) ? H5O_VERSION_LATEST : H5O_VERSION_1), (uint8_t)H5O_obj_ver_bounds[H5F_LOW_BOUND(F)]), (C))
 
 /*
  * Size of chunk "header" for each chunk
diff --git a/src/H5SM.c b/src/H5SM.c
index 3946f51..290e575 100644
--- a/src/H5SM.c
+++ b/src/H5SM.c
@@ -274,6 +274,7 @@ H5SM__type_to_flag(unsigned type_id, unsigned *type_flag)
         case H5O_FILL_ID:
             type_id = H5O_FILL_NEW_ID;
             /* Fall through... */
+            H5_ATTR_FALLTHROUGH
 
         case H5O_SDSPACE_ID:
         case H5O_DTYPE_ID:
diff --git a/src/H5Shyper.c b/src/H5Shyper.c
index 4c8e458..2acc135 100644
--- a/src/H5Shyper.c
+++ b/src/H5Shyper.c
@@ -2142,18 +2142,25 @@ loc += fast_dim_buf_off;
                     do
                       {
                         DUFF_GUTS
+                        H5_ATTR_FALLTHROUGH
                 case 7:
                         DUFF_GUTS
+                        H5_ATTR_FALLTHROUGH
                 case 6:
                         DUFF_GUTS
+                        H5_ATTR_FALLTHROUGH
                 case 5:
                         DUFF_GUTS
+                        H5_ATTR_FALLTHROUGH
                 case 4:
                         DUFF_GUTS
+                        H5_ATTR_FALLTHROUGH
                 case 3:
                         DUFF_GUTS
+                        H5_ATTR_FALLTHROUGH
                 case 2:
                         DUFF_GUTS
+                        H5_ATTR_FALLTHROUGH
                 case 1:
                         DUFF_GUTS
                   } while (--duffs_index > 0);
@@ -10013,6 +10020,7 @@ H5S_select_hyperslab(H5S_t *space, H5S_seloper_t op, const hsize_t start[],
             if(op == H5S_SELECT_SET)      /* Allow only "set" operation to proceed */
                 break;
             /* Else fall through to error */
+            H5_ATTR_FALLTHROUGH
 
         case H5S_SEL_ERROR:
         case H5S_SEL_N:
diff --git a/src/H5T.c b/src/H5T.c
index 8c8a9b7..3098325 100644
--- a/src/H5T.c
+++ b/src/H5T.c
@@ -1738,6 +1738,7 @@ H5Tcopy(hid_t type_id)
         case H5I_ERROR_CLASS:
         case H5I_ERROR_MSG:
         case H5I_ERROR_STACK:
+        case H5I_SPACE_SEL_ITER:
         case H5I_NTYPES:
         default:
             HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "not a datatype or dataset")
diff --git a/src/H5Tnative.c b/src/H5Tnative.c
index 3554f75..f40d81b 100644
--- a/src/H5Tnative.c
+++ b/src/H5Tnative.c
@@ -551,6 +551,9 @@ H5T__get_native_integer(size_t prec, H5T_sign_t sign, H5T_direction_t direction,
     FUNC_ENTER_STATIC
 
     if(direction == H5T_DIR_DEFAULT || direction == H5T_DIR_ASCEND) {
+/* Disable warning for intentional identical branches here -QAK */
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wduplicated-branches"
         if(prec <= H5T_get_precision((H5T_t *)H5I_object(H5T_NATIVE_SCHAR_g))) {
             match = H5T_NATIVE_INT_MATCH_CHAR;
             native_size = sizeof(char);
@@ -570,6 +573,7 @@ H5T__get_native_integer(size_t prec, H5T_sign_t sign, H5T_direction_t direction,
             match = H5T_NATIVE_INT_MATCH_LLONG;
             native_size = sizeof(long long);
         }
+#pragma GCC diagnostic pop
     } else if(direction == H5T_DIR_DESCEND) {
         if(prec > H5T_get_precision((H5T_t *)H5I_object(H5T_NATIVE_LONG_g))) {
             match = H5T_NATIVE_INT_MATCH_LLONG;
@@ -694,6 +698,9 @@ H5T__get_native_float(size_t size, H5T_direction_t direction, size_t *struct_ali
     HDassert(size>0);
 
     if(direction == H5T_DIR_DEFAULT || direction == H5T_DIR_ASCEND) {
+/* Disable warning for intentional identical branches here -QAK */
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wduplicated-branches"
         if(size<=sizeof(float)) {
             match=H5T_NATIVE_FLOAT_MATCH_FLOAT;
 	    native_size = sizeof(float);
@@ -717,6 +724,7 @@ H5T__get_native_float(size_t size, H5T_direction_t direction, size_t *struct_ali
             native_size = sizeof(double);
 #endif
 	}
+#pragma GCC diagnostic pop
     } else {
 #if H5_SIZEOF_LONG_DOUBLE !=0
         if(size>sizeof(double)) {
@@ -810,6 +818,9 @@ H5T__get_native_bitfield(size_t prec, H5T_direction_t direction,
     FUNC_ENTER_STATIC
 
     if(direction == H5T_DIR_DEFAULT || direction == H5T_DIR_ASCEND) {
+/* Disable warning for intentional identical branches here -QAK */
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wduplicated-branches"
         if(prec<=H5T_get_precision((H5T_t *)H5I_object(H5T_NATIVE_B8_g))) {
             tid = H5T_NATIVE_B8;
             native_size = 1;
@@ -831,6 +842,7 @@ H5T__get_native_bitfield(size_t prec, H5T_direction_t direction,
             native_size = 8;
             align = H5T_NATIVE_UINT64_ALIGN_g;
         }
+#pragma GCC diagnostic pop
     } else if(direction == H5T_DIR_DESCEND) {
         if(prec>H5T_get_precision((H5T_t *)H5I_object(H5T_NATIVE_B32_g))) {
             tid = H5T_NATIVE_B64;
diff --git a/src/H5VLint.c b/src/H5VLint.c
index 1b735f5..884b2f6 100644
--- a/src/H5VLint.c
+++ b/src/H5VLint.c
@@ -1437,6 +1437,7 @@ H5VL__object(hid_t id, H5I_type_t obj_type)
         case H5I_ERROR_CLASS:
         case H5I_ERROR_MSG:
         case H5I_ERROR_STACK:
+        case H5I_SPACE_SEL_ITER:
         case H5I_NTYPES:
         default:
             HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "unknown data object type")
diff --git a/src/H5Zshuffle.c b/src/H5Zshuffle.c
index e70ef33..b1d0722 100644
--- a/src/H5Zshuffle.c
+++ b/src/H5Zshuffle.c
@@ -185,18 +185,25 @@ H5Z_filter_shuffle(unsigned flags, size_t cd_nelmts, const unsigned cd_values[],
                         do
                           {
                             DUFF_GUTS
+                            H5_ATTR_FALLTHROUGH
                     case 7:
                             DUFF_GUTS
+                            H5_ATTR_FALLTHROUGH
                     case 6:
                             DUFF_GUTS
+                            H5_ATTR_FALLTHROUGH
                     case 5:
                             DUFF_GUTS
+                            H5_ATTR_FALLTHROUGH
                     case 4:
                             DUFF_GUTS
+                            H5_ATTR_FALLTHROUGH
                     case 3:
                             DUFF_GUTS
+                            H5_ATTR_FALLTHROUGH
                     case 2:
                             DUFF_GUTS
+                            H5_ATTR_FALLTHROUGH
                     case 1:
                             DUFF_GUTS
                       } while (--duffs_index > 0);
@@ -243,18 +250,25 @@ H5Z_filter_shuffle(unsigned flags, size_t cd_nelmts, const unsigned cd_values[],
                         do
                           {
                             DUFF_GUTS
+                            H5_ATTR_FALLTHROUGH
                     case 7:
                             DUFF_GUTS
+                            H5_ATTR_FALLTHROUGH
                     case 6:
                             DUFF_GUTS
+                            H5_ATTR_FALLTHROUGH
                     case 5:
                             DUFF_GUTS
+                            H5_ATTR_FALLTHROUGH
                     case 4:
                             DUFF_GUTS
+                            H5_ATTR_FALLTHROUGH
                     case 3:
                             DUFF_GUTS
+                            H5_ATTR_FALLTHROUGH
                     case 2:
                             DUFF_GUTS
+                            H5_ATTR_FALLTHROUGH
                     case 1:
                             DUFF_GUTS
                       } while (--duffs_index > 0);
diff --git a/src/H5checksum.c b/src/H5checksum.c
index 64d527e..4e98976 100644
--- a/src/H5checksum.c
+++ b/src/H5checksum.c
@@ -407,16 +407,27 @@ H5_checksum_lookup3(const void *key, size_t length, uint32_t initval)
     switch(length)                   /* all the case statements fall through */
     {
         case 12: c+=((uint32_t)k[11])<<24;
+                H5_ATTR_FALLTHROUGH
         case 11: c+=((uint32_t)k[10])<<16;
+                H5_ATTR_FALLTHROUGH
         case 10: c+=((uint32_t)k[9])<<8;
+                H5_ATTR_FALLTHROUGH
         case 9 : c+=k[8];
+                H5_ATTR_FALLTHROUGH
         case 8 : b+=((uint32_t)k[7])<<24;
+                H5_ATTR_FALLTHROUGH
         case 7 : b+=((uint32_t)k[6])<<16;
+                H5_ATTR_FALLTHROUGH
         case 6 : b+=((uint32_t)k[5])<<8;
+                H5_ATTR_FALLTHROUGH
         case 5 : b+=k[4];
+                H5_ATTR_FALLTHROUGH
         case 4 : a+=((uint32_t)k[3])<<24;
+                H5_ATTR_FALLTHROUGH
         case 3 : a+=((uint32_t)k[2])<<16;
+                H5_ATTR_FALLTHROUGH
         case 2 : a+=((uint32_t)k[1])<<8;
+                H5_ATTR_FALLTHROUGH
         case 1 : a+=k[0];
                  break;
         case 0 : goto done;
diff --git a/src/H5private.h b/src/H5private.h
index dad2d94..86cd615 100644
--- a/src/H5private.h
+++ b/src/H5private.h
@@ -309,6 +309,7 @@
 #   define H5_ATTR_NORETURN     /*void*/
 #   define H5_ATTR_CONST        /*void*/
 #   define H5_ATTR_PURE         /*void*/
+#   define H5_ATTR_FALLTHROUGH  /*void*/
 #else /* __cplusplus */
 #if defined(H5_HAVE_ATTRIBUTE) && !defined(__SUNPRO_C)
 #   define H5_ATTR_FORMAT(X,Y,Z)  __attribute__((format(X, Y, Z)))
@@ -316,12 +317,14 @@
 #   define H5_ATTR_NORETURN     __attribute__((noreturn))
 #   define H5_ATTR_CONST        __attribute__((const))
 #   define H5_ATTR_PURE         __attribute__((pure))
+#   define H5_ATTR_FALLTHROUGH  __attribute__((fallthrough));
 #else
 #   define H5_ATTR_FORMAT(X,Y,Z)  /*void*/
 #   define H5_ATTR_UNUSED       /*void*/
 #   define H5_ATTR_NORETURN     /*void*/
 #   define H5_ATTR_CONST        /*void*/
 #   define H5_ATTR_PURE         /*void*/
+#   define H5_ATTR_FALLTHROUGH  /*void*/
 #endif
 #endif /* __cplusplus */
 
diff --git a/src/H5trace.c b/src/H5trace.c
index 9c858fc..c5d14f5 100644
--- a/src/H5trace.c
+++ b/src/H5trace.c
@@ -173,7 +173,7 @@ H5_trace(const double *returning, const char *func, const char *type, ...)
         if(current_depth < last_call_depth) {
             /* We are at the beginning of a line */
             if(H5_debug_g.ttimes) {
-                char tmp[128];
+                char tmp[320];
 
                 HDsprintf(tmp, "%.6f", event_time.etime-first_time.etime);
                 HDfprintf(out, " %*s ", (int)HDstrlen(tmp), "");
diff --git a/test/cache_logging.c b/test/cache_logging.c
index 6fd48d8..c43609b 100644
--- a/test/cache_logging.c
+++ b/test/cache_logging.c
@@ -43,7 +43,7 @@ test_logging_api(void)
     hid_t       fid = -1;
     hid_t       gid = -1;
     hbool_t     is_currently_logging;
-    char        group_name[8];
+    char        group_name[12];
     char        filename[1024];
     int         i;
 
@@ -111,8 +111,8 @@ test_logging_api(void)
 
     /* Perform some manipulations */
     for(i = 0; i < N_GROUPS; i++) {
-        HDmemset(group_name, 0, 8);
-        HDsnprintf(group_name, 8, "%d", i);
+        HDmemset(group_name, 0, sizeof(group_name));
+        HDsnprintf(group_name, sizeof(group_name), "%d", i);
         if((gid = H5Gcreate2(fid, group_name, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0)
             TEST_ERROR;
         if(H5Gclose(gid) < 0)
diff --git a/test/cache_tagging.c b/test/cache_tagging.c
index e03defa..734c760 100644
--- a/test/cache_tagging.c
+++ b/test/cache_tagging.c
@@ -741,7 +741,7 @@ check_multi_group_creation_tags(void)
     hid_t fid = -1;          /* File Identifier */
     hid_t gid = -1;          /* Group Identifier */
     int verbose = FALSE;     /* verbose file outout */
-    char gname[10];          /* group name buffer */
+    char gname[16];          /* group name buffer */
     int i = 0;               /* iterator */
     hid_t fapl = -1;         /* File access prop list */
     haddr_t g_tag = 0;       /* Group tag value */
diff --git a/test/cmpd_dset.c b/test/cmpd_dset.c
index a8baeac..1944ce1 100644
--- a/test/cmpd_dset.c
+++ b/test/cmpd_dset.c
@@ -1808,7 +1808,7 @@ test_pack_ooo(void)
     unsigned    free_order[PACK_NMEMBS]; /* Index of remaining free slots in order */
     unsigned    num_free;           /* Number of free slots in order */
     unsigned    sub_cmpd_order;     /* Order to insert the inner compound */
-    char        name[6];            /* Member name */
+    char        name[16];           /* Member name */
     unsigned    extra_space;        /* Whether to add extra space to the end of
                                      * the compound */
     unsigned    i, j;               /* Indices */
diff --git a/test/direct_chunk.c b/test/direct_chunk.c
index 8de923e..9ea814c 100644
--- a/test/direct_chunk.c
+++ b/test/direct_chunk.c
@@ -2008,11 +2008,11 @@ error:
 static int
 test_single_chunk(unsigned config)
 {
-    hid_t fid;              /* File ID */
-    hid_t fapl;             /* File access property list ID */
-    hid_t sid;              /* Dataspace ID */
-    hid_t did;              /* Dataset ID */
-    hid_t dcpl;             /* Dataset creation property list */
+    hid_t fid = H5I_INVALID_HID;            /* File ID */
+    hid_t fapl = H5I_INVALID_HID;           /* File access property list ID */
+    hid_t sid = H5I_INVALID_HID;            /* Dataspace ID */
+    hid_t did = H5I_INVALID_HID;            /* Dataset ID */
+    hid_t dcpl = H5I_INVALID_HID;           /* Dataset creation property list */
     hsize_t dims[2] = {DIM0, DIM1};         /* Dimension sizes */
     hsize_t chunk[2] = {CHUNK0, CHUNK1};    /* Chunk dimension sizes */
     hsize_t offset[2] = {0,0};              /* Offset for writing */
diff --git a/test/dsets.c b/test/dsets.c
index a317f14..603f785 100644
--- a/test/dsets.c
+++ b/test/dsets.c
@@ -1233,14 +1233,19 @@ test_conv_buffer(hid_t fid)
     CmpField     *cf = NULL;
     CmpFieldR    *cfrR = NULL;
 
-    hid_t       dataset = -1; /* dataset ID             */
-    hid_t       space   = -1; /* data space ID          */
-    hid_t       ctype1, ctype2; /* data type ID           */
-    hid_t       arr_type1, arr_type2, arr_type3, arr_type4, arr_type5;
+    hid_t       dataset = H5I_INVALID_HID; /* dataset ID             */
+    hid_t       space   = H5I_INVALID_HID; /* data space ID          */
+    hid_t       ctype1 = H5I_INVALID_HID,
+                ctype2 = H5I_INVALID_HID; /* data type ID           */
+    hid_t       arr_type1 = H5I_INVALID_HID,
+                arr_type2 = H5I_INVALID_HID,
+                arr_type3 = H5I_INVALID_HID,
+                arr_type4 = H5I_INVALID_HID,
+                arr_type5 = H5I_INVALID_HID;
     hsize_t     dimsa[3];
     hsize_t     dimsb[1];
     hsize_t     dimsc[1];
-    hid_t       xfer_list;
+    hid_t       xfer_list = H5I_INVALID_HID;
     size_t      size;
 
     TESTING("data type conversion buffer size");
@@ -12920,7 +12925,6 @@ test_versionbounds(void)
     hid_t vspace = -1;    /* Virtual dset dataspaces */
     hid_t srcdset = -1;   /* Source datset */
     hid_t vdset = -1;     /* Virtual dataset */
-    hid_t null_dspace = -1;     /* Data space of H5S_NULL */
     hsize_t dims[1] = {3};      /* Data space current size */
     char  srcfilename[FILENAME_BUF_SIZE];
     char  vfilename1[FILENAME_BUF_SIZE];
diff --git a/test/evict_on_close.c b/test/evict_on_close.c
index 9918829..b7d30a9 100644
--- a/test/evict_on_close.c
+++ b/test/evict_on_close.c
@@ -73,7 +73,7 @@ const char *FILENAMES[] = {
 #define SUBGROUP_NAME_SIZE          16
 
 /* Prototypes */
-static hbool_t verify_tag_not_in_cache(H5F_t *f, haddr_t tag);
+static hbool_t verify_tag_not_in_cache(const H5F_t *f, haddr_t tag);
 static herr_t check_evict_on_close_api(void);
 static hid_t generate_eoc_test_file(hid_t fapl_id);
 static herr_t check_dset_scheme(hid_t fid, const char *dset_name);
@@ -90,8 +90,8 @@ static herr_t check_group_layout(hid_t fid, const char *group_name);
  *
  *-------------------------------------------------------------------------
  */
-static hbool_t
-verify_tag_not_in_cache(H5F_t *f, haddr_t tag)
+static H5_ATTR_PURE hbool_t
+verify_tag_not_in_cache(const H5F_t *f, haddr_t tag)
 {
     H5C_t *cache_ptr = NULL;                /* cache pointer                */
     int i = 0;                              /* iterator                     */
diff --git a/test/external_common.h b/test/external_common.h
index cc2b5fb..1e4fe7a 100644
--- a/test/external_common.h
+++ b/test/external_common.h
@@ -33,11 +33,6 @@ static const char *EXT_FNAME[] = {
     NULL
 };
 
-static const char *EXT_ENV_FNAME[] = {
-    "extern_env_dir/env_file_1",
-    NULL
-};
-
 /* A similar collection of files is used for the tests that
  * perform file I/O.
  */
diff --git a/test/external_env.c b/test/external_env.c
index 55f68be..1bf0cf0 100644
--- a/test/external_env.c
+++ b/test/external_env.c
@@ -16,6 +16,11 @@
  */
 #include "external_common.h"
 
+static const char *EXT_ENV_FNAME[] = {
+    "extern_env_dir/env_file_1",
+    NULL
+};
+
 
 /*-------------------------------------------------------------------------
  * Function:    test_path_env
diff --git a/test/fheap.c b/test/fheap.c
index c7f6ff0..846f03e 100644
--- a/test/fheap.c
+++ b/test/fheap.c
@@ -7599,7 +7599,7 @@ test_man_incr_insert_remove(hid_t fapl, H5HF_create_t *cparam, fheap_test_param_
     unsigned char heap_id[100][MAX_HEAP_ID_LEN]; /* Heap ID for object inserted */
     struct a_type_t1 {
         char a[10];
-        char b[29];
+        char b[40];
     } obj1, obj2;                       /* Objects to insert/remove */
     size_t      id_len;                 /* Size of fractal heap IDs */
     fheap_heap_state_t state;           /* State of fractal heap */
@@ -7640,14 +7640,14 @@ test_man_incr_insert_remove(hid_t fapl, H5HF_create_t *cparam, fheap_test_param_
      */
     TESTING("incremental object insertion and removal")
 
+    HDmemset(&obj1, 0, sizeof(obj1));
+    HDmemset(&obj2, 0, sizeof(obj2));
     for(i = 0; i < 100; i++) {
-        HDsprintf(obj1.b, "%s%d", "ABCDEFGHIJKLMNOPQRSTUVWXYZ", i);
-
         for(j = 0; j < i; j++) {
-            HDsprintf(obj2.b, "%s%d", "ABCDEFGHIJKLMNOPQRSTUVWXYZ", j);
-
             if(H5HF_remove(fh, heap_id[j]) < 0)
                 FAIL_STACK_ERROR
+
+            HDsprintf(obj2.b, "%s%2d", "ABCDEFGHIJKLMNOPQRSTUVWXYZ", j);
             if(H5HF_insert(fh, (sizeof(obj2)), &obj2, heap_id[j]) < 0)
                 FAIL_STACK_ERROR
         } /* end for */
@@ -7658,6 +7658,7 @@ test_man_incr_insert_remove(hid_t fapl, H5HF_create_t *cparam, fheap_test_param_
 
         /* Insert object */
         HDmemset(heap_id[i], 0, id_len);
+        HDsprintf(obj1.b, "%s%2d", "ABCDEFGHIJKLMNOPQRSTUVWXYZ", i);
         if(H5HF_insert(fh, (sizeof(obj1)), &obj1, heap_id[i]) < 0)
             FAIL_STACK_ERROR
     } /* end for */
diff --git a/test/file_image.c b/test/file_image.c
index 0dba236..86dd13e 100644
--- a/test/file_image.c
+++ b/test/file_image.c
@@ -580,7 +580,7 @@ test_core(void)
     file = H5Fopen(copied_filename, H5F_ACC_RDONLY, fapl);
     VERIFY(file >= 0, "H5Fopen failed");
     VERIFY((udata->used_callbacks == MALLOC) || 
-            (udata->used_callbacks == MALLOC | UDATA_COPY | UDATA_FREE), "opening a core file used the wrong callbacks");
+            (udata->used_callbacks == (MALLOC | UDATA_COPY | UDATA_FREE)), "opening a core file used the wrong callbacks");
     VERIFY(udata->malloc_src == H5FD_FILE_IMAGE_OP_FILE_OPEN, "Malloc callback came from wrong sourc in core open");
 
     /* Close file */
diff --git a/test/flush1.c b/test/flush1.c
index fefa8d0..ac5f9ef 100644
--- a/test/flush1.c
+++ b/test/flush1.c
@@ -73,7 +73,7 @@ create_file(const char *filename, hid_t fapl_id, hbool_t swmr)
     hid_t   fid = -1;               /* file ID                          */
     hid_t   top_gid = -1;           /* containing group ID              */
     hid_t   gid = -1;               /* subgroup ID                      */
-    char    group_name[16];         /* group name                       */
+    char    group_name[32];         /* group name                       */
     unsigned    flags;              /* file open flags                  */
     int     i;                      /* iterator                         */
 
diff --git a/test/flush2.c b/test/flush2.c
index 6e8aee7..8ebfb75 100644
--- a/test/flush2.c
+++ b/test/flush2.c
@@ -135,7 +135,7 @@ file_ok(const char *filename, hid_t fapl_id, hbool_t check_second_dset)
     hid_t   fid = -1;               /* file ID                          */
     hid_t   top_gid = -1;           /* containing group ID              */
     hid_t   gid = -1;               /* subgroup ID                      */
-    char    group_name[16];         /* group name                       */
+    char    group_name[32];         /* group name                       */
     int     i;                      /* iterator                         */
 
     /* open file */
diff --git a/test/hyperslab.c b/test/hyperslab.c
index feb96bd..d8c00c9 100644
--- a/test/hyperslab.c
+++ b/test/hyperslab.c
@@ -819,12 +819,8 @@ test_transpose(size_t nx, size_t ny)
     dst_stride[1] = (hsize_t)(nx * sizeof(*src));
 
     /* Copy and transpose */
-    if(nx == ny)
-        H5VM_stride_copy(2, (hsize_t)sizeof(*src), size, dst_stride, dst,
-                src_stride, src);
-    else
-        H5VM_stride_copy(2, (hsize_t)sizeof(*src), size, dst_stride, dst,
-                src_stride, src);
+    H5VM_stride_copy(2, (hsize_t)sizeof(*src), size, dst_stride, dst,
+            src_stride, src);
 
     /* Check */
     for(i = 0; i < nx; i++) {
diff --git a/test/links.c b/test/links.c
index 520f784..3166954 100644
--- a/test/links.c
+++ b/test/links.c
@@ -7759,6 +7759,7 @@ done:
             case H5I_ERROR_CLASS:
             case H5I_ERROR_MSG:
             case H5I_ERROR_STACK:
+            case H5I_SPACE_SEL_ITER:
             case H5I_NTYPES:
             default:
               return -1;
@@ -7847,6 +7848,7 @@ done:
             case H5I_ERROR_CLASS:
             case H5I_ERROR_MSG:
             case H5I_ERROR_STACK:
+            case H5I_SPACE_SEL_ITER:
             case H5I_NTYPES:
             default:
                 return -1;
diff --git a/test/page_buffer.c b/test/page_buffer.c
index b9b31f8..e11a6d6 100644
--- a/test/page_buffer.c
+++ b/test/page_buffer.c
@@ -98,7 +98,7 @@ create_file(char *filename, hid_t fcpl, hid_t fapl)
     int         i;
     int         num_elements;
     int         j;
-    char        dset_name[10];
+    char        dset_name[32];
 
     if((file_id = H5Fcreate(filename, H5F_ACC_TRUNC, fcpl, fapl)) < 0)
         FAIL_STACK_ERROR;
@@ -235,7 +235,7 @@ open_file(char *filename, hid_t fapl, hsize_t page_size,
     int         i;
     int         j;
     int         num_elements;
-    char        dset_name[10];
+    char        dset_name[32];
     H5F_t       *f = NULL;
 
     if((file_id = H5Fopen(filename, H5F_ACC_RDONLY, fapl)) < 0)
diff --git a/test/tattr.c b/test/tattr.c
index b83ed9f..c7a2c23 100644
--- a/test/tattr.c
+++ b/test/tattr.c
@@ -10065,7 +10065,7 @@ test_attr_bug2(hid_t fcpl, hid_t fapl)
     hid_t   tid;            /* Datatype ID */
     hid_t   gcpl;           /* Group creation property list */
     hsize_t dims[2] = {10, 100}; /* Attribute dimensions */
-    char    aname[4];       /* Attribute name */
+    char    aname[16];       /* Attribute name */
     unsigned i;             /* index */
     herr_t  ret;            /* Generic return status */
     htri_t  tri_ret;        /* htri_t return status */
diff --git a/test/tfile.c b/test/tfile.c
index 140bd14..c15064a 100644
--- a/test/tfile.c
+++ b/test/tfile.c
@@ -1446,6 +1446,7 @@ test_obj_count_and_id(hid_t fid1, hid_t fid2, hid_t did, hid_t gid1,
                     case H5I_ERROR_CLASS:
                     case H5I_ERROR_MSG:
                     case H5I_ERROR_STACK:
+                    case H5I_SPACE_SEL_ITER:
                     case H5I_NTYPES:
                     default:
                         ERROR("H5Fget_obj_ids");
diff --git a/test/th5s.c b/test/th5s.c
index 6632a4c..c5dfa97 100644
--- a/test/th5s.c
+++ b/test/th5s.c
@@ -30,6 +30,7 @@
  * This file also needs to access the dataspace testing code.
  */
 #define H5S_FRIEND      /*suppress error about including H5Spkg   */
+#define H5S_TESTING	/*suppress warning about H5S testing funcs*/
 #include "H5Spkg.h"     /* Dataspaces               */
 
 /*
diff --git a/test/tselect.c b/test/tselect.c
index d912df5..ad435cb 100644
--- a/test/tselect.c
+++ b/test/tselect.c
@@ -10546,7 +10546,7 @@ test_shape_same_dr__full_space_vs_slice(int test_num,
                                         hbool_t expected_result)
 {
     char	test_desc_0[128];
-    char	test_desc_1[128];
+    char	test_desc_1[256];
     int         i;
     hid_t	n_cube_0_sid;  /* the fully selected hyper cube */
     hid_t	n_cube_1_sid;  /* the hyper cube in which a slice is selected */
@@ -10831,7 +10831,7 @@ test_shape_same_dr__checkerboard(int test_num,
                                  hbool_t expected_result)
 {
     char	test_desc_0[128];
-    char	test_desc_1[128];
+    char	test_desc_1[256];
     int         i;
     int		dims_selected = 0;
     hid_t	n_cube_0_sid;  /* the checker board selected
@@ -11443,7 +11443,7 @@ test_shape_same_dr__irregular(int test_num,
                               hbool_t expected_result)
 {
     char	test_desc_0[128];
-    char	test_desc_1[128];
+    char	test_desc_1[256];
     int		edge_size = 10;
     int         i;
     int         j;
diff --git a/tools/lib/h5diff.c b/tools/lib/h5diff.c
index 594bf51..3ee5393 100644
--- a/tools/lib/h5diff.c
+++ b/tools/lib/h5diff.c
@@ -1344,7 +1344,6 @@ diff_match(hid_t file1_id, const char *grp1, trav_info_t *info1,
     }
 #endif /* H5_HAVE_PARALLEL */
 
-out:
     opts->err_stat = opts->err_stat | ret_value;
 
 /* free table */
diff --git a/tools/lib/h5diff_array.c b/tools/lib/h5diff_array.c
index 9d5f062..0169131 100644
--- a/tools/lib/h5diff_array.c
+++ b/tools/lib/h5diff_array.c
@@ -783,12 +783,11 @@ static hsize_t diff_datum(
                 }
 
                 /* check object type */
-                if (ret_value >= 0)
-                    if (obj1_type != obj2_type) {
-                        parallel_print("Different object types referenced: <%s> and <%s>", obj1, obj2);
-                        opts->not_cmp = 1;
-                        HGOTO_DONE (opts->err_stat);
-                    }
+                if (obj1_type != obj2_type) {
+                    parallel_print("Different object types referenced: <%s> and <%s>", obj1, obj2);
+                    opts->not_cmp = 1;
+                    HGOTO_DONE (opts->err_stat);
+                }
 
                 if ((obj1_id = H5Rdereference2(container1_id, H5P_DEFAULT, H5R_OBJECT, _mem1)) < 0) {
                     opts->err_stat = 1;
diff --git a/tools/src/h5repack/h5repack.c b/tools/src/h5repack/h5repack.c
index a63e56f..e96dea5 100644
--- a/tools/src/h5repack/h5repack.c
+++ b/tools/src/h5repack/h5repack.c
@@ -713,7 +713,7 @@ static int check_objects(const char* fname, pack_opt_t *options) {
     hid_t         did = -1;
     hid_t         sid = -1;
     unsigned int  i;
-    unsigned int  uf;
+    int  ifil;
     trav_table_t *travt = NULL;
 
     /* nothing to do */
@@ -747,7 +747,7 @@ static int check_objects(const char* fname, pack_opt_t *options) {
      */
 
     if (options->verbose)
-        printf("Opening file. Searching %d objects to modify ...\n", travt->nobjs);
+        printf("Opening file. Searching %zu objects to modify ...\n", travt->nobjs);
 
     for (i = 0; i < options->op_tbl->nelems; i++) {
         char* name = options->op_tbl->objs[i].path;
@@ -761,17 +761,17 @@ static int check_objects(const char* fname, pack_opt_t *options) {
         if (options->verbose)
             printf("...Found\n");
 
-        for (uf = 0; uf < options->op_tbl->objs[i].nfilters; uf++) {
-            if (options->op_tbl->objs[i].filter[uf].filtn < 0)
+        for (ifil = 0; ifil < options->op_tbl->objs[i].nfilters; ifil++) {
+            if (options->op_tbl->objs[i].filter[ifil].filtn < 0)
                 HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "invalid filter");
             /* check for extra filter conditions */
-            switch (options->op_tbl->objs[i].filter[uf].filtn) {
+            switch (options->op_tbl->objs[i].filter[ifil].filtn) {
             /* chunk size must be smaller than pixels per block */
             case H5Z_FILTER_SZIP:
                 {
                     int j;
                     hsize_t csize = 1;
-                    unsigned ppb = options->op_tbl->objs[i].filter[uf].cd_values[0];
+                    unsigned ppb = options->op_tbl->objs[i].filter[ifil].cd_values[0];
                     hsize_t dims[H5S_MAX_RANK];
                     int rank;
 
@@ -807,7 +807,7 @@ static int check_objects(const char* fname, pack_opt_t *options) {
             default:
                 break;
             }
-        } /* for uf */
+        } /* for ifil */
     } /* for i */
 
 done:
diff --git a/tools/src/h5repack/h5repack_copy.c b/tools/src/h5repack/h5repack_copy.c
index 0567269..8122d6d 100644
--- a/tools/src/h5repack/h5repack_copy.c
+++ b/tools/src/h5repack/h5repack_copy.c
@@ -33,20 +33,6 @@
 /* size of buffer/# of bytes to xfer at a time when copying userblock */
 #define USERBLOCK_XFER_SIZE     512
 
-/* check H5Dread()/H5Dwrite() error, e.g. memory allocation error inside the library. */
-#define CHECK_H5DRW_ERROR(_fun, _fail, _did, _mtid, _msid, _fsid, _pid, _buf)  {  \
-    H5E_BEGIN_TRY {  \
-        if(_fun(_did, _mtid, _msid, _fsid, _pid, _buf) < 0) {  \
-            hid_t _err_num = 0; \
-            char _msg[80]; \
-            H5Ewalk2(H5E_DEFAULT, H5E_WALK_DOWNWARD, walk_error_callback, &_err_num); \
-            H5Eget_msg(_err_num, NULL, _msg, (size_t)80); \
-            error_msg("%s %s -- %s\n", #_fun, "failed", _msg); \
-            HGOTO_DONE(_fail) \
-        } \
-    } H5E_END_TRY; \
-}
-
 /*-------------------------------------------------------------------------
  * local functions
  *-------------------------------------------------------------------------
@@ -61,15 +47,7 @@ static int copy_user_block(const char *infile, const char *outfile,
 #if defined (H5REPACK_DEBUG_USER_BLOCK)
 static void print_user_block(const char *filename, hid_t fid);
 #endif
-static herr_t walk_error_callback(unsigned n, const H5E_error2_t *err_desc, void *udata);
 
-/* get the major number from the error stack. */
-static herr_t walk_error_callback(H5_ATTR_UNUSED unsigned n, const H5E_error2_t *err_desc, void *udata) {
-    if (err_desc)
-        *((hid_t *) udata) = err_desc->maj_num;
-
-    return 0;
-}
 
 /*-------------------------------------------------------------------------
  * Function: copy_objects
@@ -634,7 +612,7 @@ int do_copy_objects(hid_t fidin, hid_t fidout, trav_table_t *travt,
     unsigned crt_order_flags; /* group creation order flag */
     unsigned i;
     unsigned u;
-    unsigned uf;
+    int ifil;
     int is_ref = 0;
     htri_t is_named;
     hbool_t limit_maxdims;
@@ -740,8 +718,8 @@ int do_copy_objects(hid_t fidin, hid_t fidout, trav_table_t *travt,
                 if (options->op_tbl->objs) {
                     for (u = 0; u < options->op_tbl->nelems; u++) {
                         if (HDstrcmp(travt->objs[i].name, options->op_tbl->objs[u].path) == 0)
-                            for (uf = 0; uf < options->op_tbl->objs[uf].nfilters; uf++) {
-                                if (options->op_tbl->objs[u].filter[uf].filtn > 0)
+                            for (ifil = 0; ifil < options->op_tbl->objs[ifil].nfilters; ifil++) {
+                                if (options->op_tbl->objs[u].filter[ifil].filtn > 0)
                                     req_filter = 1;
                             }
                     }
@@ -1350,7 +1328,7 @@ print_dataset_info(hid_t dcpl_id, char *objname, double ratio, int pr)
     if (!pr)
         printf(FORMAT_OBJ, "dset", objname);
     else {
-        char str[255], temp[28];
+        char str[512], temp[512];
 
         HDstrcpy(str, "dset     ");
         HDstrcat(str, strfilter);
diff --git a/tools/src/h5repack/h5repack_filters.c b/tools/src/h5repack/h5repack_filters.c
index 3d9472a..7e32def 100644
--- a/tools/src/h5repack/h5repack_filters.c
+++ b/tools/src/h5repack/h5repack_filters.c
@@ -42,7 +42,8 @@ static int aux_copy_obj(hid_t dcpl_id, /* dataset creation property list */
     H5D_layout_t layout;
     int          rank;           /* rank of dataset */
     hsize_t      chsize[64];     /* chunk size in elements */
-    unsigned int i;
+    int i;
+    unsigned u;
 
     /* get information about input filters */
     if ((nfilters = H5Pget_nfilters(dcpl_id)) < 0)
@@ -65,8 +66,8 @@ static int aux_copy_obj(hid_t dcpl_id, /* dataset creation property list */
         if ((rank = H5Pget_chunk(dcpl_id, NELMTS(chsize), chsize/*out*/)) < 0)
             HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Pget_chunk failed");
         objout->chunk.rank = rank;
-        for (i = 0; i < rank; i++)
-            objout->chunk.chunk_lengths[i] = chsize[i];
+        for (u = 0; u < (unsigned)rank; u++)
+            objout->chunk.chunk_lengths[u] = chsize[u];
     }
 
 done:
@@ -85,8 +86,7 @@ static int aux_find_obj(const char* name, /* object name from traverse list */
         pack_info_t *obj                  /*OUT*/) /* info about object to filter */
 {
     char         *pdest = NULL;
-    char         *pname = NULL;
-    int          result;
+    const char   *pname = NULL;
     unsigned int i;
 
     for (i = 0; i < options->op_tbl->nelems; i++) {
diff --git a/tools/src/h5stat/h5stat.c b/tools/src/h5stat/h5stat.c
index 8109b93..450f731 100644
--- a/tools/src/h5stat/h5stat.c
+++ b/tools/src/h5stat/h5stat.c
@@ -509,8 +509,7 @@ dataset_stats(iter_t *iter, const char *name, const H5O_info_t *oi)
         HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "attribute_stats() failed");
 
     /* Get storage info */
-    if((storage = H5Dget_storage_size(did)) < 0)
-        HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Dget_storage_size() failed");
+    storage = H5Dget_storage_size(did);
 
     /* Gather layout statistics */
     if((dcpl = H5Dget_create_plist(did)) < 0)
diff --git a/tools/test/h5dump/h5dumpgentest.c b/tools/test/h5dump/h5dumpgentest.c
index 946ca04..3a414d1 100644
--- a/tools/test/h5dump/h5dumpgentest.c
+++ b/tools/test/h5dump/h5dumpgentest.c
@@ -1889,7 +1889,7 @@ static void gent_str2(void)
 
 
     int i;
-    char buf[LENSTR+10];
+    char buf[LENSTR+20];
     char buf2[3*LENSTR2];
     hsize_t sdim;
 
@@ -1941,7 +1941,7 @@ static void gent_str2(void)
 
     for(i = 0; (hsize_t)i < sdim; i++) {
         start[0] = (hsize_t)i;
-        sprintf(buf, "This is row %1d of type H5T_STR_NULLTERM of", i);
+        sprintf(buf, "This is row %d of type H5T_STR_NULLTERM of", i);
         H5Tset_size(memtype, HDstrlen(buf)+1);
         H5Sselect_hyperslab(hyper_space, H5S_SELECT_SET, start, stride, count, block);
         H5Dwrite(dataset, memtype, mem_space, hyper_space, H5P_DEFAULT, buf);
@@ -1954,7 +1954,7 @@ static void gent_str2(void)
 
     for(i = 0; (hsize_t)i < sdim; i++) {
         start[0] = (hsize_t)i;
-        sprintf(buf, "This is row %1d of type H5T_STR_NULLTERM of string array", i);
+        sprintf(buf, "This is row %d of type H5T_STR_NULLTERM of string array", i);
         H5Tset_size(memtype, HDstrlen(buf)+1);
         H5Sselect_hyperslab(hyper_space, H5S_SELECT_SET, start, stride, count, block);
         H5Dwrite(dataset, memtype, mem_space, hyper_space, H5P_DEFAULT, buf);
@@ -1974,7 +1974,7 @@ static void gent_str2(void)
 
     for(i = 0;(hsize_t) i < sdim; i++) {
         start[0] = (hsize_t)i;
-        sprintf(buf, "This is row %1d of type H5T_STR_NULLPAD of", i);
+        sprintf(buf, "This is row %d of type H5T_STR_NULLPAD of", i);
         H5Tset_size(memtype, HDstrlen(buf)+1);
         H5Sselect_hyperslab(hyper_space, H5S_SELECT_SET, start, stride, count, block);
         H5Dwrite(dataset, memtype, mem_space, hyper_space, H5P_DEFAULT, buf);
@@ -1988,7 +1988,7 @@ static void gent_str2(void)
 
     for(i = 0; (hsize_t)i < sdim; i++) {
         start[0] = (hsize_t)i;
-        sprintf(buf, "This is row %1d of type H5T_STR_NULLPAD of string array", i);
+        sprintf(buf, "This is row %d of type H5T_STR_NULLPAD of string array", i);
         H5Tset_size(memtype, HDstrlen(buf)+1);
         H5Sselect_hyperslab(hyper_space, H5S_SELECT_SET, start, stride, count, block);
         H5Dwrite(dataset, memtype, mem_space, hyper_space, H5P_DEFAULT, buf);
@@ -2007,7 +2007,7 @@ static void gent_str2(void)
 
     for(i = 0; (hsize_t)i < sdim; i++) {
         start[0] = (hsize_t)i;
-        sprintf(buf, "This is row %1d of type H5T_STR_SPACEPAD of", i);
+        sprintf(buf, "This is row %d of type H5T_STR_SPACEPAD of", i);
         H5Tset_size(memtype, HDstrlen(buf) + 1);
         H5Sselect_hyperslab(hyper_space, H5S_SELECT_SET, start, stride, count, block);
         H5Dwrite(dataset, memtype, mem_space, hyper_space, H5P_DEFAULT, buf);
@@ -2021,7 +2021,7 @@ static void gent_str2(void)
 
     for(i = 0; (hsize_t)i < sdim; i++) {
         start[0] = (hsize_t)i;
-        sprintf(buf, "This is row %1d of type H5T_STR_SPACEPAD of string array", i);
+        sprintf(buf, "This is row %d of type H5T_STR_SPACEPAD of string array", i);
         H5Tset_size(memtype, HDstrlen(buf) + 1);
         H5Sselect_hyperslab(hyper_space, H5S_SELECT_SET, start, stride, count, block);
         H5Dwrite(dataset, memtype, mem_space, hyper_space, H5P_DEFAULT, buf);
@@ -7532,16 +7532,6 @@ gent_nodata(void)
 {
     hid_t fid, dataset, space;
     hsize_t dims[2];
-    uint8_t  dsetu8[F66_XDIM][F66_YDIM8],   valu8bits;
-    uint16_t dsetu16[F66_XDIM][F66_YDIM16], valu16bits;
-    uint32_t dsetu32[F66_XDIM][F66_YDIM32], valu32bits;
-    uint64_t dsetu64[F66_XDIM][F66_YDIM64], valu64bits;
-    int8_t  dset8[F66_XDIM][F66_YDIM8],   val8bits;
-    int16_t dset16[F66_XDIM][F66_YDIM16], val16bits;
-    int32_t dset32[F66_XDIM][F66_YDIM32], val32bits;
-    int64_t dset64[F66_XDIM][F66_YDIM64], val64bits;
-    double  dsetdbl[F66_XDIM][F66_YDIM8];
-    unsigned int i, j;
 
     fid = H5Fcreate(FILE87, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT);
 
diff --git a/tools/test/h5repack/h5repacktst.c b/tools/test/h5repack/h5repacktst.c
index 0ae570b..a89bf10 100644
--- a/tools/test/h5repack/h5repacktst.c
+++ b/tools/test/h5repack/h5repacktst.c
@@ -2907,10 +2907,10 @@ out:
 static
 int make_all_filters(hid_t loc_id)
 {
-    hid_t    dcpl; /* dataset creation property list */
-    hid_t    sid;  /* dataspace ID */
-    hid_t    dtid;
-    hid_t    dsid;
+    hid_t    dcpl = H5I_INVALID_HID; /* dataset creation property list */
+    hid_t    sid = H5I_INVALID_HID;  /* dataspace ID */
+    hid_t    dtid = H5I_INVALID_HID;
+    hid_t    dsid = H5I_INVALID_HID;
 #if defined (H5_HAVE_FILTER_SZIP)
     unsigned szip_options_mask=H5_SZIP_ALLOW_K13_OPTION_MASK|H5_SZIP_NN_OPTION_MASK;
     unsigned szip_pixels_per_block=8;
@@ -3083,7 +3083,7 @@ int make_early(void)
     hid_t   tid=-1;
     hid_t   dcpl=-1;
     int     i;
-    char    name[10];
+    char    name[16];
     int     iter=100;
 
     if ((fid = H5Fcreate(FNAME5, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT)) < 0)
@@ -3178,7 +3178,7 @@ int make_layout(hid_t loc_id)
     hsize_t  chunk_dims[RANK]={CDIM1,CDIM2};
     int      buf[DIM1][DIM2];
     int      i, j, n;
-    char     name[6];
+    char     name[16];
 
 
     for (i=n=0; i<DIM1; i++)
diff --git a/tools/test/perform/chunk_cache.c b/tools/test/perform/chunk_cache.c
index 429f70a..47734b6 100644
--- a/tools/test/perform/chunk_cache.c
+++ b/tools/test/perform/chunk_cache.c
@@ -106,8 +106,8 @@ cleanup (void)
  */
 static int create_dset1(hid_t file)
 {
-    hid_t        dataspace, dataset;
-    hid_t        dcpl;
+    hid_t        dataspace = H5I_INVALID_HID, dataset = H5I_INVALID_HID;
+    hid_t        dcpl = H5I_INVALID_HID;
     hsize_t      dims[RANK]  = {DSET1_DIM1, DSET1_DIM2};
     hsize_t      chunk_dims[RANK] = {CHUNK1_DIM1, CHUNK1_DIM2};
     int          data[DSET1_DIM1][DSET1_DIM2];    /* data for writing */
@@ -167,8 +167,8 @@ error:
  */
 static int create_dset2(hid_t file)
 {
-    hid_t        dataspace, dataset;
-    hid_t        dcpl;
+    hid_t        dataspace = H5I_INVALID_HID, dataset = H5I_INVALID_HID;
+    hid_t        dcpl = H5I_INVALID_HID;
     hsize_t      dims[RANK]  = {DSET2_DIM1, DSET2_DIM2};
     hsize_t      chunk_dims[RANK] = {CHUNK2_DIM1, CHUNK2_DIM2};
     int          data[DSET2_DIM1][DSET2_DIM2];    /* data for writing */
@@ -226,10 +226,10 @@ error:
  */
 static int check_partial_chunks_perf(hid_t file)
 {
-    hid_t        dataset;
-    hid_t        filespace;
-    hid_t        memspace;
-    hid_t        dapl;
+    hid_t        dataset = H5I_INVALID_HID;
+    hid_t        filespace = H5I_INVALID_HID;
+    hid_t        memspace = H5I_INVALID_HID;
+    hid_t        dapl = H5I_INVALID_HID;
     
     int          rdata[DSET1_DIM2];   /* data for reading */
     int          i;
@@ -297,10 +297,10 @@ error:
  */
 static int check_hash_value_perf(hid_t file)
 {
-    hid_t        dataset;
-    hid_t        filespace;
-    hid_t        memspace;
-    hid_t        dapl;
+    hid_t        dataset = H5I_INVALID_HID;
+    hid_t        filespace = H5I_INVALID_HID;
+    hid_t        memspace = H5I_INVALID_HID;
+    hid_t        dapl = H5I_INVALID_HID;
     
     int          rdata[DSET2_DIM1];   /* data for reading */
     int          i;