MINOR: flags/http_ana: use flag dumping for txn flags

The new function is txn_show_flags(). It dumps the TXN flags
as well as the client and server cookie types.
diff --git a/dev/flags/flags.c b/dev/flags/flags.c
index c24bde8..9c6a71b 100644
--- a/dev/flags/flags.c
+++ b/dev/flags/flags.c
@@ -90,55 +90,8 @@
 
 void show_txn_flags(unsigned int f)
 {
-	printf("txn->flags  = ");
-
-	if (!f) {
-		printf("0\n");
-		return;
-	}
-
-	SHOW_FLAG(f, TX_L7_RETRY);
-	SHOW_FLAG(f, TX_D_L7_RETRY);
-	SHOW_FLAG(f, TX_NOT_FIRST);
-	SHOW_FLAG(f, TX_USE_PX_CONN);
-	SHOW_FLAG(f, TX_CACHE_HAS_SEC_KEY);
-	SHOW_FLAG(f, TX_CON_WANT_TUN);
-
-	SHOW_FLAG(f, TX_CACHE_IGNORE);
-	SHOW_FLAG(f, TX_CACHE_COOK);
-	SHOW_FLAG(f, TX_CACHEABLE);
-	SHOW_FLAG(f, TX_SCK_PRESENT);
-
-	//printf("%s", f ? "" : " | ");
-	switch (f & TX_SCK_MASK) {
-	case TX_SCK_NONE:                        f &= ~TX_SCK_MASK ; /*printf("TX_SCK_NONE%s",     f ? " | " : "");*/ break;
-	case TX_SCK_FOUND:                       f &= ~TX_SCK_MASK ; printf("TX_SCK_FOUND%s",    f ? " | " : ""); break;
-	case TX_SCK_DELETED:                     f &= ~TX_SCK_MASK ; printf("TX_SCK_DELETED%s",  f ? " | " : ""); break;
-	case TX_SCK_INSERTED:                    f &= ~TX_SCK_MASK ; printf("TX_SCK_INSERTED%s", f ? " | " : ""); break;
-	case TX_SCK_REPLACED:                    f &= ~TX_SCK_MASK ; printf("TX_SCK_REPLACED%s", f ? " | " : ""); break;
-	case TX_SCK_UPDATED:                     f &= ~TX_SCK_MASK ; printf("TX_SCK_UPDATED%s",  f ? " | " : ""); break;
-	default: printf("TX_SCK_MASK(%02x)", f); f &= ~TX_SCK_MASK ; printf("%s",                f ? " | " : ""); break;
-	}
-
-	//printf("%s", f ? "" : " | ");
-	switch (f & TX_CK_MASK) {
-	case TX_CK_NONE:                        f &= ~TX_CK_MASK ; /*printf("TX_CK_NONE%s",    f ? " | " : "");*/ break;
-	case TX_CK_INVALID:                     f &= ~TX_CK_MASK ; printf("TX_CK_INVALID%s", f ? " | " : ""); break;
-	case TX_CK_DOWN:                        f &= ~TX_CK_MASK ; printf("TX_CK_DOWN%s",    f ? " | " : ""); break;
-	case TX_CK_VALID:                       f &= ~TX_CK_MASK ; printf("TX_CK_VALID%s",   f ? " | " : ""); break;
-	case TX_CK_EXPIRED:                     f &= ~TX_CK_MASK ; printf("TX_CK_EXPIRED%s", f ? " | " : ""); break;
-	case TX_CK_OLD:                         f &= ~TX_CK_MASK ; printf("TX_CK_OLD%s",     f ? " | " : ""); break;
-	case TX_CK_UNUSED:                      f &= ~TX_CK_MASK ; printf("TX_CK_UNUSED%s",  f ? " | " : ""); break;
-	default: printf("TX_CK_MASK(%02x)", f); f &= ~TX_CK_MASK ; printf("%s",              f ? " | " : ""); break;
-	}
-
-	SHOW_FLAG(f, TX_CLTARPIT);
-	SHOW_FLAG(f, TX_CONST_REPLY);
-
-	if (f) {
-		printf("EXTRA(0x%08x)", f);
-	}
-	putchar('\n');
+	txn_show_flags(tmpbuf, sizeof(tmpbuf), " | ", f);
+	printf("txn->flags = %s\n", tmpbuf);
 }
 
 void show_strm_flags(unsigned int f)
diff --git a/include/haproxy/http_ana-t.h b/include/haproxy/http_ana-t.h
index b267ebe..735a2fb 100644
--- a/include/haproxy/http_ana-t.h
+++ b/include/haproxy/http_ana-t.h
@@ -28,7 +28,9 @@
 
 /* These are the flags that are found in txn->flags */
 
-/* action flags */
+/* action flags.
+ * Please also update the txn_show_flags() function below in case of changes.
+ */
 /* Unusued: 0x00000001..0x00000004 */
 #define TX_CONST_REPLY  0x00000008      /* The http reply must not be rewritten (don't eval after-response ruleset) */
 #define TX_CLTARPIT	0x00000010	/* the transaction is tarpitted (anti-dos) */
@@ -73,6 +75,40 @@
 
 #define TX_L7_RETRY     0x000800000     /* The transaction may attempt L7 retries */
 #define TX_D_L7_RETRY   0x001000000     /* Disable L7 retries on this transaction, even if configured to do it */
+
+/* This function is used to report flags in debugging tools. Please reflect
+ * below any single-bit flag addition above in the same order via the
+ * __APPEND_FLAG and __APPEND_ENUM macros. The new end of the buffer is
+ * returned.
+ */
+static forceinline char *txn_show_flags(char *buf, size_t len, const char *delim, uint flg)
+{
+#define _(f, ...)     __APPEND_FLAG(buf, len, delim, flg, f, #f, __VA_ARGS__)
+#define _e(m, e, ...) __APPEND_ENUM(buf, len, delim, flg, m, e, #e, __VA_ARGS__)
+	/* prologue */
+	_(0);
+	/* flags & enums */
+	_(TX_SCK_PRESENT, _(TX_CACHEABLE, _(TX_CACHE_COOK, _(TX_CACHE_IGNORE,
+	_(TX_CON_WANT_TUN, _(TX_CACHE_HAS_SEC_KEY, _(TX_USE_PX_CONN,
+	_(TX_NOT_FIRST, _(TX_L7_RETRY, _(TX_D_L7_RETRY))))))))));
+
+	_e(TX_SCK_MASK, TX_SCK_FOUND,     _e(TX_SCK_MASK, TX_SCK_DELETED,
+	_e(TX_SCK_MASK, TX_SCK_INSERTED,  _e(TX_SCK_MASK, TX_SCK_REPLACED,
+	_e(TX_SCK_MASK, TX_SCK_UPDATED)))));
+
+	_e(TX_CK_MASK, TX_CK_INVALID,     _e(TX_CK_MASK, TX_CK_DOWN,
+	_e(TX_CK_MASK, TX_CK_VALID,       _e(TX_CK_MASK, TX_CK_EXPIRED,
+	_e(TX_CK_MASK, TX_CK_OLD,         _e(TX_CK_MASK, TX_CK_UNUSED))))));
+
+	_(TX_CONST_REPLY, _(TX_CLTARPIT));
+	/* epilogue */
+	_(~0U);
+	return buf;
+#undef _e
+#undef _
+}
+
+
 /*
  * HTTP message status flags (msg->flags)
  */