Fixes various warnings noticed on Windows (#425)

* Fixes various warnings noticed on Windows

- Adds a prototype for our implementation of vasprintf
- Return type of H5_get_utf16_str() is now non-const
- Fixes possible uninitialized return type in Wremove_utf8
- Better isolation of fork() code in accum.c:test_swmr_write_big()
- Better isolation of non-zlib code in dsets.c:test_filter_delete()
- Removed unused variable in trefer.c:test_reference_cmpnd_obj()

* Fixes clang-format issues

1 files changed, 10 insertions, 15 deletions

diff --git a/test/accum.c b/test/accum.c
index e9542cf..08fe926 100644
--- a/test/accum.c
+++ b/test/accum.c
@@ -2092,6 +2092,7 @@ error:
 unsigned
 test_swmr_write_big(hbool_t newest_format)
 {
+#if defined(H5_HAVE_FORK) && defined(H5_HAVE_WAITPID) && defined(H5_HAVE_UNISTD_H)
     hid_t    fid  = -1;   /* File ID */
     hid_t    fapl = -1;   /* File access property list */
     H5F_t *  rf   = NULL; /* File pointer */
@@ -2099,26 +2100,16 @@ test_swmr_write_big(hbool_t newest_format)
     uint8_t *wbuf2 = NULL, *rbuf = NULL; /* Buffers for reading & writing */
     uint8_t  wbuf[1024];                 /* Buffer for reading & writing */
     unsigned u;                          /* Local index variable */
-#ifdef H5_HAVE_UNISTD_H
-    pid_t pid;                      /* Process ID */
-#endif                              /* H5_HAVE_UNISTD_H */
-    int     status;                 /* Status returned from child process */
-    char *  driver         = NULL;  /* VFD string (from env variable) */
-    hbool_t api_ctx_pushed = FALSE; /* Whether API context pushed */
+    pid_t    pid;                        /* Process ID */
+    int      status;                     /* Status returned from child process */
+    char *   driver         = NULL;      /* VFD string (from env variable) */
+    hbool_t  api_ctx_pushed = FALSE;     /* Whether API context pushed */
 
     if (newest_format)
         TESTING("SWMR write of large metadata: with latest format")
     else
         TESTING("SWMR write of large metadata: with non-latest-format")
 
-#if !(defined(H5_HAVE_FORK) && defined(H5_HAVE_WAITPID))
-
-    SKIPPED();
-    HDputs("    Test skipped due to fork or waitpid not defined.");
-    return 0;
-
-#else /* defined(H5_HAVE_FORK && defined(H5_HAVE_WAITPID) */
-
     /* Skip this test if SWMR I/O is not supported for the VFD specified
      * by the environment variable.
      */
@@ -2296,7 +2287,11 @@ error:
 
     return 1;
 
-#endif
+#else
+    SKIPPED();
+    HDputs("    Test skipped due to fork, waitpid, or pid_t not defined.");
+    return 0;
+#endif /* defined(H5_HAVE_FORK) && defined(H5_HAVE_WAITPID) && defined(H5_HAVE_UNISTD_H) */
 
 } /* end test_swmr_write_big() */