Attachment 53577 Details for Bug 11191 – [1/2] Promote DBusBasicValue and DBus8ByteStruct to be API

[patch] [1/2] Promote DBusBasicValue and DBus8ByteStruct to be API

0001-Promote-DBusBasicValue-and-DBus8ByteStruct-to-be-API.patch (text/plain), 7.65 KB, created by Simon McVittie on 2011-11-15 08:38:15 UTC

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Creator: Simon McVittie

Created: 2011-11-15 08:38:15 UTC

Size: 7.65 KB

patch

obsolete

>From c6040e8d49d235f2071fa995e9f8fbeb28556862 Mon Sep 17 00:00:00 2001
>From: Simon McVittie <simon.mcvittie@collabora.co.uk>
>Date: Mon, 10 Oct 2011 11:20:31 +0100
>Subject: [PATCH 1/2] Promote DBusBasicValue and DBus8ByteStruct to be API
>
>In practice, D-Bus bindings end up reinventing DBusBasicValue anyway,
>so it might as well be API.
>
>Also stop claiming that all basic-typed values are guaranteed to fit in
>8 bytes - this is not true if your platform has more than 8-byte pointers
>(I'm not aware of any such platform now, but let's not rule it out).
>
>Bug: https://bugs.freedesktop.org/show_bug.cgi?id=11191
>Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
>---
> dbus/dbus-marshal-basic.c          |   13 +++++++++--
> dbus/dbus-marshal-basic.h          |   34 ---------------------------------
> dbus/dbus-marshal-recursive-util.c |    8 +++---
> dbus/dbus-message.c                |   16 +++++++-------
> dbus/dbus-types.h                  |   37 ++++++++++++++++++++++++++++++++++++
> 5 files changed, 59 insertions(+), 49 deletions(-)
>
>diff --git a/dbus/dbus-marshal-basic.c b/dbus/dbus-marshal-basic.c
>index b139853..2534b61 100644
>--- a/dbus/dbus-marshal-basic.c
>+++ b/dbus/dbus-marshal-basic.c
>@@ -65,6 +65,13 @@ _DBUS_STATIC_ASSERT (sizeof (dbus_uint64_t) == 8);
> _DBUS_ASSERT_ALIGNMENT (dbus_uint64_t, <=, 8);
> #endif
> 
>+_DBUS_STATIC_ASSERT (sizeof (DBusBasicValue) >= 8);
>+/* The alignment of a DBusBasicValue might conceivably be > 8 because of the
>+ * pointer, so we don't assert about it */
>+
>+_DBUS_STATIC_ASSERT (sizeof (DBus8ByteStruct) == 8);
>+_DBUS_ASSERT_ALIGNMENT (DBus8ByteStruct, <=, 8);
>+
> /**
>  * @defgroup DBusMarshal marshaling and unmarshaling
>  * @ingroup  DBusInternals
>@@ -119,7 +126,7 @@ pack_8_octets (DBusBasicValue     value,
>   else
>     *((dbus_uint64_t*)(data)) = DBUS_UINT64_TO_BE (value.u64);
> #else
>-  *(DBus8ByteStruct*)data = value.u64;
>+  *(DBus8ByteStruct*)data = value.eight;
>   swap_8_octets ((DBusBasicValue*)data, byte_order);
> #endif
> }
>@@ -169,7 +176,7 @@ swap_8_octets (DBusBasicValue    *value,
> #ifdef DBUS_HAVE_INT64
>       value->u64 = DBUS_UINT64_SWAP_LE_BE (value->u64);
> #else
>-      swap_bytes ((unsigned char *)value, 8);
>+      swap_bytes (&value->bytes, 8);
> #endif
>     }
> }
>@@ -190,7 +197,7 @@ unpack_8_octets (int                  byte_order,
>   else
>     r.u64 = DBUS_UINT64_FROM_BE (*(dbus_uint64_t*)data);
> #else
>-  r.u64 = *(DBus8ByteStruct*)data;
>+  r.eight = *(DBus8ByteStruct*)data;
>   swap_8_octets (&r, byte_order);
> #endif
> 
>diff --git a/dbus/dbus-marshal-basic.h b/dbus/dbus-marshal-basic.h
>index 0c27fc9..95547ef 100644
>--- a/dbus/dbus-marshal-basic.h
>+++ b/dbus/dbus-marshal-basic.h
>@@ -146,40 +146,6 @@
> #  define DBUS_UINT64_FROM_BE(val) (DBUS_UINT64_TO_BE (val))
> #endif /* DBUS_HAVE_INT64 */
> 
>-#ifndef DBUS_HAVE_INT64
>-/**
>- * An 8-byte struct you could use to access int64 without having
>- * int64 support
>- */
>-typedef struct
>-{
>-  dbus_uint32_t first32;  /**< first 32 bits in the 8 bytes (beware endian issues) */
>-  dbus_uint32_t second32; /**< second 32 bits in the 8 bytes (beware endian issues) */
>-} DBus8ByteStruct;
>-#endif /* DBUS_HAVE_INT64 */
>-
>-/**
>- * A simple 8-byte value union that lets you access 8 bytes as if they
>- * were various types; useful when dealing with basic types via
>- * void pointers and varargs.
>- */
>-typedef union
>-{
>-  dbus_int16_t  i16;   /**< as int16 */
>-  dbus_uint16_t u16;   /**< as int16 */
>-  dbus_int32_t  i32;   /**< as int32 */
>-  dbus_uint32_t u32;   /**< as int32 */
>-#ifdef DBUS_HAVE_INT64
>-  dbus_int64_t  i64;   /**< as int64 */
>-  dbus_uint64_t u64;   /**< as int64 */
>-#else
>-  DBus8ByteStruct u64; /**< as 8-byte-struct */
>-#endif
>-  double dbl;          /**< as double */
>-  unsigned char byt;   /**< as byte */
>-  char *str;           /**< as char* */
>-} DBusBasicValue;
>-
> #ifdef DBUS_DISABLE_ASSERT
> #define _dbus_unpack_uint16(byte_order, data)           \
>    (((byte_order) == DBUS_LITTLE_ENDIAN) ?              \
>diff --git a/dbus/dbus-marshal-recursive-util.c b/dbus/dbus-marshal-recursive-util.c
>index 3508bb0..f7d629a 100644
>--- a/dbus/dbus-marshal-recursive-util.c
>+++ b/dbus/dbus-marshal-recursive-util.c
>@@ -38,8 +38,8 @@ basic_value_zero (DBusBasicValue *value)
> #ifdef DBUS_HAVE_INT64
>   value->u64 = 0;
> #else
>-  value->u64.first32 = 0;
>-  value->u64.second32 = 0;
>+  value->eight.first32 = 0;
>+  value->eight.second32 = 0;
> #endif
> }
> 
>@@ -59,8 +59,8 @@ basic_value_equal (int             type,
> #ifdef DBUS_HAVE_INT64
>       return lhs->u64 == rhs->u64;
> #else
>-      return lhs->u64.first32 == rhs->u64.first32 &&
>-        lhs->u64.second32 == rhs->u64.second32;
>+      return lhs->eight.first32 == rhs->eight.first32 &&
>+        lhs->eight.second32 == rhs->eight.second32;
> #endif
>     }
> }
>diff --git a/dbus/dbus-message.c b/dbus/dbus-message.c
>index a95ad0f..33dab8a 100644
>--- a/dbus/dbus-message.c
>+++ b/dbus/dbus-message.c
>@@ -2129,22 +2129,22 @@ dbus_message_iter_get_signature (DBusMessageIter *iter)
>  * descriptors), you can get all the array elements at once with
>  * dbus_message_iter_get_fixed_array(). Otherwise, you have to iterate
>  * over the container's contents one value at a time.
>- * 
>- * All basic-typed values are guaranteed to fit in 8 bytes. So you can
>- * write code like this:
>+ *
>+ * All basic-typed values are guaranteed to fit in a #DBusBasicValue,
>+ * so in versions of libdbus that have that type, you can write code like this:
>  *
>  * @code
>- * dbus_uint64_t value;
>+ * DBusBasicValue value;
>  * int type;
>  * dbus_message_iter_get_basic (&read_iter, &value);
>  * type = dbus_message_iter_get_arg_type (&read_iter);
>  * dbus_message_iter_append_basic (&write_iter, type, &value);
>  * @endcode
>  *
>- * On some really obscure platforms dbus_uint64_t might not exist, if
>- * you need to worry about this you will know.  dbus_uint64_t is just
>- * one example of a type that's large enough to hold any possible
>- * value, you could use a struct or char[8] instead if you like.
>+ * (All D-Bus basic types are either numeric and 8 bytes or smaller, or
>+ * behave like a string; so in older versions of libdbus, DBusBasicValue
>+ * can be replaced with union { char *string; unsigned char bytes[8]; },
>+ * for instance.)
>  *
>  * @param iter the iterator
>  * @param value location to store the value
>diff --git a/dbus/dbus-types.h b/dbus/dbus-types.h
>index 54f348f..7251d65 100644
>--- a/dbus/dbus-types.h
>+++ b/dbus/dbus-types.h
>@@ -134,6 +134,43 @@ typedef dbus_uint32_t  dbus_bool_t;
>  * giving a literal such as "325145246765ULL"
>  */
> 
>+/**
>+ * An 8-byte struct you could use to access int64 without having
>+ * int64 support
>+ */
>+typedef struct
>+{
>+  dbus_uint32_t first32;  /**< first 32 bits in the 8 bytes (beware endian issues) */
>+  dbus_uint32_t second32; /**< second 32 bits in the 8 bytes (beware endian issues) */
>+} DBus8ByteStruct;
>+
>+/**
>+ * A simple value union that lets you access bytes as if they
>+ * were various types; useful when dealing with basic types via
>+ * void pointers and varargs.
>+ *
>+ * This union also contains a pointer member (which can be used
>+ * to retrieve a string from dbus_message_iter_get_basic(), for
>+ * instance), so on future platforms it could conceivably be larger
>+ * than 8 bytes.
>+ */
>+typedef union
>+{
>+  unsigned char bytes[8]; /**< as 8 individual bytes */
>+  dbus_int16_t  i16;   /**< as int16 */
>+  dbus_uint16_t u16;   /**< as int16 */
>+  dbus_int32_t  i32;   /**< as int32 */
>+  dbus_uint32_t u32;   /**< as int32 */
>+#ifdef DBUS_HAVE_INT64
>+  dbus_int64_t  i64;   /**< as int64 */
>+  dbus_uint64_t u64;   /**< as int64 */
>+#endif
>+  DBus8ByteStruct eight; /**< as 8-byte struct */
>+  double dbl;          /**< as double */
>+  unsigned char byt;   /**< as byte */
>+  char *str;           /**< as char* */
>+} DBusBasicValue;
>+
> /** @} */
> 
> #endif /* DBUS_TYPES_H */
>-- 
>1.7.7.2
>

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