Add PRIsize, to use as the print format for size_t, and use it.

size_t may be bigger than unsigned long, so don't just cast to unsigned
long and print with %lu".  (In practice, the value is unlikely to be
bigger, but this is cleaner.)

We could use %zu on UN*X, as we require C99 support and C99 requires
support for z as a size modifier, but MSVC doesn't support z as a size
modifier until Visual Studio 2017.

4 files changed, 29 insertions, 22 deletions

diff --git a/pcap/pcap-inttypes.h b/pcap/pcap-inttypes.h
index af2c23c8..8b1eb8b9 100644
--- a/pcap/pcap-inttypes.h
+++ b/pcap/pcap-inttypes.h
@@ -106,12 +106,23 @@
       #define PRIu64	"llu"
     #endif
   #endif
+
+  /*
+   * MSVC's support library doesn't support %zu to print a size_t until
+   * Visual Studio 2017, but supports %Iu earlier, so use that.
+   */
+  #define PRIsize	"Iu"
 #elif defined(__MINGW32__) || !defined(_WIN32)
   /*
    * Compiler is MinGW or target is UN*X or MS-DOS.  Just use
    * <inttypes.h>.
    */
   #include <inttypes.h>
+
+  /*
+   * Assume the support library supports %zu; it's required by C99.
+   */
+  #define PRIsize	"zu"
 #endif
 
 #endif /* pcap/pcap-inttypes.h */
diff --git a/savefile.c b/savefile.c
index ec44ef4f..830669ec 100644
--- a/savefile.c
+++ b/savefile.c
@@ -365,9 +365,8 @@ pcap_fopen_offline_with_tstamp_precision(FILE *fp, u_int precision,
 			    errno, "error reading dump file");
 		} else {
 			pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
-			    "truncated dump file; tried to read %lu file header bytes, only got %lu",
-			    (unsigned long)sizeof(magic),
-			    (unsigned long)amt_read);
+			    "truncated dump file; tried to read %" PRIsize " file header bytes, only got %" PRIsize,
+			    sizeof(magic), amt_read);
 		}
 		return (NULL);
 	}
diff --git a/sf-pcap.c b/sf-pcap.c
index 1e587cb1..b3260f9d 100644
--- a/sf-pcap.c
+++ b/sf-pcap.c
@@ -176,9 +176,8 @@ pcap_check_header(bpf_u_int32 magic, FILE *fp, u_int precision, char *errbuf,
 			    errno, "error reading dump file");
 		} else {
 			pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
-			    "truncated dump file; tried to read %lu file header bytes, only got %lu",
-			    (unsigned long)sizeof(hdr),
-			    (unsigned long)amt_read);
+			    "truncated dump file; tried to read %" PRIsize " file header bytes, only got %" PRIsize,
+			    sizeof(hdr), amt_read);
 		}
 		*err = 1;
 		return (NULL);
@@ -449,9 +448,8 @@ pcap_next_packet(pcap_t *p, struct pcap_pkthdr *hdr, u_char **data)
 		} else {
 			if (amt_read != 0) {
 				pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
-				    "truncated dump file; tried to read %lu header bytes, only got %lu",
-				    (unsigned long)ps->hdrsize,
-				    (unsigned long)amt_read);
+				    "truncated dump file; tried to read %" PRIsize " header bytes, only got %" PRIsize,
+				    ps->hdrsize, amt_read);
 				return (-1);
 			}
 			/* EOF */
@@ -610,8 +608,8 @@ pcap_next_packet(pcap_t *p, struct pcap_pkthdr *hdr, u_char **data)
 				 * the read finished.
 				 */
 				pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
-				    "truncated dump file; tried to read %u captured bytes, only got %lu",
-				    p->snapshot, (unsigned long)amt_read);
+				    "truncated dump file; tried to read %u captured bytes, only got %" PRIsize,
+				    p->snapshot, amt_read);
 			}
 			return (-1);
 		}
@@ -634,8 +632,8 @@ pcap_next_packet(pcap_t *p, struct pcap_pkthdr *hdr, u_char **data)
 					    "error reading dump file");
 				} else {
 					pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
-					    "truncated dump file; tried to read %u captured bytes, only got %lu",
-					    hdr->caplen, (unsigned long)bytes_read);
+					    "truncated dump file; tried to read %u captured bytes, only got %" PRIsize,
+					    hdr->caplen, bytes_read);
 				}
 				return (-1);
 			}
@@ -683,8 +681,8 @@ pcap_next_packet(pcap_t *p, struct pcap_pkthdr *hdr, u_char **data)
 				    "error reading dump file");
 			} else {
 				pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
-				    "truncated dump file; tried to read %u captured bytes, only got %lu",
-				    hdr->caplen, (unsigned long)amt_read);
+				    "truncated dump file; tried to read %u captured bytes, only got %" PRIsize,
+				    hdr->caplen, amt_read);
 			}
 			return (-1);
 		}
diff --git a/sf-pcapng.c b/sf-pcapng.c
index 970c675c..06c896ac 100644
--- a/sf-pcapng.c
+++ b/sf-pcapng.c
@@ -261,9 +261,8 @@ read_bytes(FILE *fp, void *buf, size_t bytes_to_read, int fail_on_eof,
 			if (amt_read == 0 && !fail_on_eof)
 				return (0);	/* EOF */
 			pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
-			    "truncated dump file; tried to read %lu bytes, only got %lu",
-			    (unsigned long)bytes_to_read,
-			    (unsigned long)amt_read);
+			    "truncated dump file; tried to read %" PRIsize " bytes, only got %" PRIsize,
+			    bytes_to_read, amt_read);
 		}
 		return (-1);
 	}
@@ -311,9 +310,9 @@ read_block(FILE *fp, pcap_t *p, struct block_cursor *cursor, char *errbuf)
 	if (bhdr.total_length < sizeof(struct block_header) +
 	    sizeof(struct block_trailer)) {
 		pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
-		    "block in pcapng dump file has a length of %u < %lu",
+		    "block in pcapng dump file has a length of %u < %" PRIsize,
 		    bhdr.total_length,
-		    (unsigned long)(sizeof(struct block_header) + sizeof(struct block_trailer)));
+		    sizeof(struct block_header) + sizeof(struct block_trailer));
 		return (-1);
 	}
 
@@ -831,9 +830,9 @@ pcap_ng_check_header(bpf_u_int32 magic, FILE *fp, u_int precision, char *errbuf,
 	 */
 	if (total_length < sizeof(*bhdrp) + sizeof(*shbp) + sizeof(struct block_trailer)) {
 		pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
-		    "Section Header Block in pcapng dump file has a length of %u < %lu",
+		    "Section Header Block in pcapng dump file has a length of %u < %" PRIsize,
 		    total_length,
-		    (unsigned long)(sizeof(*bhdrp) + sizeof(*shbp) + sizeof(struct block_trailer)));
+		    sizeof(*bhdrp) + sizeof(*shbp) + sizeof(struct block_trailer));
 		*err = 1;
 		return (NULL);
 	}