From: Wayne Davison <wayned@samba.org>
Date: Wed, 14 Oct 2009 04:07:46 +0000 (-0700)
Subject: Avoid type-punned compiler warnings for the byteorder.h macros
X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/commitdiff_plain/df6350a8b83a9e669f5e5c822bf2dc929526a128

Avoid type-punned compiler warnings for the byteorder.h macros
by using inline functions for the 4-char <-> uint32 conversions.
---

diff --git a/byteorder.h b/byteorder.h
index 6dd9b459..146b861f 100644
--- a/byteorder.h
+++ b/byteorder.h
@@ -19,6 +19,7 @@
  */
 
 #undef CAREFUL_ALIGNMENT
+#undef AVOID_BYTEORDER_INLINE
 
 /* We know that the x86 can handle misalignment and has the same
  * byte order (LSB-first) as the 32-bit numbers we transmit. */
@@ -32,21 +33,68 @@
 
 #define CVAL(buf,pos) (((unsigned char *)(buf))[pos])
 #define UVAL(buf,pos) ((uint32)CVAL(buf,pos))
-#define SCVAL(buf,pos,val) (CVAL(buf,pos) = (val))
 
 #if CAREFUL_ALIGNMENT
+
 #define PVAL(buf,pos) (UVAL(buf,pos)|UVAL(buf,(pos)+1)<<8)
 #define IVAL(buf,pos) (PVAL(buf,pos)|PVAL(buf,(pos)+2)<<16)
 #define SSVALX(buf,pos,val) (CVAL(buf,pos)=(val)&0xFF,CVAL(buf,pos+1)=(val)>>8)
 #define SIVALX(buf,pos,val) (SSVALX(buf,pos,val&0xFFFF),SSVALX(buf,pos+2,val>>16))
 #define SIVAL(buf,pos,val) SIVALX((buf),(pos),((uint32)(val)))
-#else
-/* this handles things for architectures like the 386 that can handle
-   alignment errors */
-/*
-   WARNING: This section is dependent on the length of int32
-   being correct. set CAREFUL_ALIGNMENT if it is not.
-*/
+
+#define IVALu(buf,pos) IVAL(buf,pos)
+#define SIVALu(buf,pos,val) SIVAL(buf,pos,val)
+
+#else /* !CAREFUL_ALIGNMENT */
+
+/* This handles things for architectures like the 386 that can handle alignment errors.
+ * WARNING: This section is dependent on the length of an int32 (and thus a uint32)
+ * being correct (4 bytes)!  Set CAREFUL_ALIGNMENT if it is not. */
+
+# ifdef AVOID_BYTEORDER_INLINE
+
 #define IVAL(buf,pos) (*(uint32 *)((char *)(buf) + (pos)))
 #define SIVAL(buf,pos,val) IVAL(buf,pos)=((uint32)(val))
-#endif
+
+#define IVALu(buf,pos) IVAL(buf,pos)
+#define SIVALu(buf,pos,val) SIVAL(buf,pos,val)
+
+# else /* !AVOID_BYTEORDER_INLINE */
+
+static inline uint32
+IVALu(const uchar *buf, int pos)
+{
+	union {
+		const uchar *b;
+		const uint32 *num;
+	} u;
+	u.b = buf + pos;
+	return *u.num;
+}
+
+static inline void
+SIVALu(uchar *buf, int pos, uint32 val)
+{
+	union {
+		uchar *b;
+		uint32 *num;
+	} u;
+	u.b = buf + pos;
+	*u.num = val;
+}
+
+static inline uint32
+IVAL(const char *buf, int pos)
+{
+	return IVALu((uchar*)buf, pos);
+}
+
+static inline void
+SIVAL(char *buf, int pos, uint32 val)
+{
+	SIVALu((uchar*)buf, pos, val);
+}
+
+# endif /* !AVOID_BYTEORDER_INLINE */
+
+#endif /* !CAREFUL_ALIGNMENT */
diff --git a/checksum.c b/checksum.c
index 811b5b60..90d6ee3a 100644
--- a/checksum.c
+++ b/checksum.c
@@ -56,7 +56,7 @@ void get_checksum2(char *buf, int32 len, char *sum)
 		md5_begin(&m);
 		md5_update(&m, (uchar *)buf, len);
 		if (checksum_seed) {
-			SIVAL(seedbuf, 0, checksum_seed);
+			SIVALu(seedbuf, 0, checksum_seed);
 			md5_update(&m, seedbuf, 4);
 		}
 		md5_result(&m, (uchar *)sum);
diff --git a/hashtable.c b/hashtable.c
index d5f1d110..219210de 100644
--- a/hashtable.c
+++ b/hashtable.c
@@ -106,7 +106,7 @@ void *hashtable_find(struct hashtable *tbl, int64 key, int allocate_if_missing)
 		uchar buf[4], *keyp = buf;
 		int i;
 
-		SIVAL(buf, 0, key);
+		SIVALu(buf, 0, key);
 		for (ndx = 0, i = 0; i < 4; i++) {
 			ndx += keyp[i];
 			ndx += (ndx << 10);
diff --git a/lib/md5.c b/lib/md5.c
index 2c5b9014..4baa9638 100644
--- a/lib/md5.c
+++ b/lib/md5.c
@@ -38,22 +38,22 @@ static void md5_process(md_context *ctx, const uchar data[CSUM_CHUNK])
 	C = ctx->C;
 	D = ctx->D;
 
-	X[0] = IVAL(data, 0);
-	X[1] = IVAL(data, 4);
-	X[2] = IVAL(data, 8);
-	X[3] = IVAL(data, 12);
-	X[4] = IVAL(data, 16);
-	X[5] = IVAL(data, 20);
-	X[6] = IVAL(data, 24);
-	X[7] = IVAL(data, 28);
-	X[8] = IVAL(data, 32);
-	X[9] = IVAL(data, 36);
-	X[10] = IVAL(data, 40);
-	X[11] = IVAL(data, 44);
-	X[12] = IVAL(data, 48);
-	X[13] = IVAL(data, 52);
-	X[14] = IVAL(data, 56);
-	X[15] = IVAL(data, 60);
+	X[0] = IVALu(data, 0);
+	X[1] = IVALu(data, 4);
+	X[2] = IVALu(data, 8);
+	X[3] = IVALu(data, 12);
+	X[4] = IVALu(data, 16);
+	X[5] = IVALu(data, 20);
+	X[6] = IVALu(data, 24);
+	X[7] = IVALu(data, 28);
+	X[8] = IVALu(data, 32);
+	X[9] = IVALu(data, 36);
+	X[10] = IVALu(data, 40);
+	X[11] = IVALu(data, 44);
+	X[12] = IVALu(data, 48);
+	X[13] = IVALu(data, 52);
+	X[14] = IVALu(data, 56);
+	X[15] = IVALu(data, 60);
 
 #define S(x,n) ((x << n) | ((x & 0xFFFFFFFF) >> (32 - n)))
 
@@ -192,8 +192,8 @@ void md5_result(md_context *ctx, uchar digest[MD5_DIGEST_LEN])
 	     | (ctx->totalN2 <<  3);
 	low  = (ctx->totalN <<  3);
 
-	SIVAL(msglen, 0, low);
-	SIVAL(msglen, 4, high);
+	SIVALu(msglen, 0, low);
+	SIVALu(msglen, 4, high);
 
 	last = ctx->totalN & 0x3F;
 	padn = last < 56 ? 56 - last : 120 - last;
@@ -201,10 +201,10 @@ void md5_result(md_context *ctx, uchar digest[MD5_DIGEST_LEN])
 	md5_update(ctx, md5_padding, padn);
 	md5_update(ctx, msglen, 8);
 
-	SIVAL(digest, 0, ctx->A);
-	SIVAL(digest, 4, ctx->B);
-	SIVAL(digest, 8, ctx->C);
-	SIVAL(digest, 12, ctx->D);
+	SIVALu(digest, 0, ctx->A);
+	SIVALu(digest, 4, ctx->B);
+	SIVALu(digest, 8, ctx->C);
+	SIVALu(digest, 12, ctx->D);
 }
 
 void get_md5(uchar *out, const uchar *input, int n)