New wrapper macro for printf("%zu"), for old VS compat.

A user reports that Visual Studio 2013 and earlier have printf
implementations in their C library that don't support the 'z' modifier
to indicate that an integer argument is size_t. The 'I' modifier
apparently works in place of it.

To avoid littering ifdefs everywhere, I've invented my own inttypes.h
style macros to wrap size_t formatting directives, which are defined
to %zu and %zx normally, or %Iu and %Ix in old-VS mode. Those are in
defs.h, and they're used everywhere that a %z might otherwise get into
the Windows build.

(cherry picked from commit 82a7e8c4ac)

defs.h

@@ -22,9 +22,16 @@
 #define PRIdMAX "I64d"
 #define PRIXMAX "I64X"
 #define SCNu64 "I64u"
+#define SIZEx "Ix"
+#define SIZEu "Iu"
 uintmax_t strtoumax(const char *nptr, char **endptr, int base);
 #else
 #include <inttypes.h>
+/* Because we still support older MSVC libraries which don't recognise the
+ * standard C "z" modifier for size_t-sized integers, we must use an
+ * inttypes.h-style macro for those */
+#define SIZEx "zx"
+#define SIZEu "zu"
 #endif
 
 #if defined __GNUC__ || defined __clang__

logging.c

@@ -344,7 +344,7 @@ void log_packet(LogContext *ctx, int direction, int type,
         /* If we're about to stop omitting, it's time to say how
          * much we omitted. */
         if ((blktype != PKTLOG_OMIT) && omitted) {
-            logprintf(ctx, "  (%zu byte%s omitted)\r\n",
+            logprintf(ctx, "  (%"SIZEu" byte%s omitted)\r\n",
                       omitted, (omitted==1?"":"s"));
             omitted = 0;
         }
@@ -352,7 +352,8 @@ void log_packet(LogContext *ctx, int direction, int type,
         /* (Re-)initialise dumpdata as necessary
          * (start of row, or if we've just stopped omitting) */
         if (!output_pos && !omitted)
-            sprintf(dumpdata, "  %08zx%*s\r\n", p-(p%16), 1+3*16+2+16, "");
+            sprintf(dumpdata, "  %08"SIZEx"%*s\r\n",
+                    p-(p%16), 1+3*16+2+16, "");
 
         /* Deal with the current byte. */
         if (blktype == PKTLOG_OMIT) {
@@ -387,7 +388,7 @@ void log_packet(LogContext *ctx, int direction, int type,
 
     /* Tidy up */
     if (omitted)
-        logprintf(ctx, "  (%zu byte%s omitted)\r\n",
+        logprintf(ctx, "  (%"SIZEu" byte%s omitted)\r\n",
                   omitted, (omitted==1?"":"s"));
     logflush(ctx);
 }

sshprng.c

@@ -177,7 +177,7 @@ static void prng_seed_BinarySink_write(
     prng *pr = BinarySink_DOWNCAST(bs, prng);
     prng_impl *pi = container_of(pr, prng_impl, Prng);
     assert(pi->keymaker);
-    prngdebug("prng: got %zu bytes of seed\n", len);
+    prngdebug("prng: got %"SIZEu" bytes of seed\n", len);
     put_data(pi->keymaker, data, len);
 }
 
@@ -228,7 +228,7 @@ void prng_read(prng *pr, void *vout, size_t size)
 
     assert(!pi->keymaker);
 
-    prngdebug("prng_read %zu\n", size);
+    prngdebug("prng_read %"SIZEu"\n", size);
 
     uint8_t *out = (uint8_t *)vout;
     for (; size > 0; size--) {
@@ -256,7 +256,7 @@ void prng_add_entropy(prng *pr, unsigned source_id, ptrlen data)
         index++;
     }
 
-    prngdebug("prng_add_entropy source=%u size=%zu -> collector %zi\n",
+    prngdebug("prng_add_entropy source=%u size=%"SIZEu" -> collector %zi\n",
               source_id, data.len, index);
 
     put_datapl(pi->collectors[index], data);
@@ -272,7 +272,7 @@ void prng_add_entropy(prng *pr, unsigned source_id, ptrlen data)
         uint32_t reseed_index = ++pi->reseeds;
         prngdebug("prng entropy reseed #%"PRIu32"\n", reseed_index);
         for (size_t i = 0; i < NCOLLECTORS; i++) {
-            prngdebug("emptying collector %zu\n", i);
+            prngdebug("emptying collector %"SIZEu"\n", i);
             ssh_hash_final(pi->collectors[i], pi->pending_output);
             put_data(&pi->Prng, pi->pending_output, pi->hashalg->hlen);
             pi->collectors[i] = ssh_hash_new(pi->hashalg);

sshpubk.c

@@ -1362,8 +1362,8 @@ char *ssh1_pubkey_str(RSAKey *key)
 
     dec1 = mp_get_decimal(key->exponent);
     dec2 = mp_get_decimal(key->modulus);
-    buffer = dupprintf("%zd %s %s%s%s", mp_get_nbits(key->modulus), dec1, dec2,
-                       key->comment ? " " : "",
+    buffer = dupprintf("%"SIZEu" %s %s%s%s", mp_get_nbits(key->modulus),
+                       dec1, dec2, key->comment ? " " : "",
                        key->comment ? key->comment : "");
     sfree(dec1);
     sfree(dec2);

sshrsa.c

@@ -296,7 +296,7 @@ char *rsa_ssh1_fingerprint(RSAKey *key)
     ssh_hash_final(hash, digest);
 
     out = strbuf_new();
-    strbuf_catf(out, "%zu ", mp_get_nbits(key->modulus));
+    strbuf_catf(out, "%"SIZEu" ", mp_get_nbits(key->modulus));
     for (i = 0; i < 16; i++)
         strbuf_catf(out, "%s%02x", i ? ":" : "", digest[i]);
     if (key->comment)
@@ -779,7 +779,7 @@ char *rsa2_invalid(ssh_key *key, unsigned flags)
     const ssh_hashalg *halg = rsa2_hash_alg_for_flags(flags, &sign_alg_name);
     if (nbytes < rsa_pkcs1_length_of_fixed_parts(halg)) {
         return dupprintf(
-            "%zu-bit RSA key is too short to generate %s signatures",
+            "%"SIZEu"-bit RSA key is too short to generate %s signatures",
             bits, sign_alg_name);
     }
 

testcrypt.c

@@ -1115,7 +1115,7 @@ int main(int argc, char **argv)
         for (size_t i = 0; i < sb->len; i++)
             if (sb->s[i] == '\n')
                 lines++;
-        fprintf(outfp, "%zu\n%s", lines, sb->s);
+        fprintf(outfp, "%"SIZEu"\n%s", lines, sb->s);
         fflush(outfp);
         strbuf_free(sb);
         sfree(line);

testsc.c

@@ -160,7 +160,7 @@ VOLATILE_WRAPPED_DEFN(, void, log_to_file, (const char *filename))
 static const char *outdir = NULL;
 char *log_filename(const char *basename, size_t index)
 {
-    return dupprintf("%s/%s.%04zu", outdir, basename, index);
+    return dupprintf("%s/%s.%04"SIZEu, outdir, basename, index);
 }
 
 static char *last_filename;
@@ -1574,7 +1574,7 @@ int main(int argc, char **argv)
         printf("All tests passed\n");
         return 0;
     } else {
-        printf("%zu tests failed\n", nrun - npass);
+        printf("%"SIZEu" tests failed\n", nrun - npass);
         return 1;
     }
 }

windows/winpgnt.c

@@ -884,7 +884,7 @@ static char *answer_filemapping_message(const char *mapname)
         mapsize = mbi.RegionSize;
     }
 #ifdef DEBUG_IPC
-    debug("region size = %zd\n", mapsize);
+    debug("region size = %"SIZEu"\n", mapsize);
 #endif
     if (mapsize < 5) {
         err = dupstr("mapping smaller than smallest possible request");