Change the callback function to use void**.

NOTE: This change breaks backwards-compatibility by default.
If you have old callback functions, you can define PB_OLD_CALLBACK_STYLE
to retain the old behaviour.

If you want to convert your old callbacks to new signature, you need
to do the following:

1) Change decode callback argument to   void **arg
      and encode callback argument to   void * const *arg.

2) Change any reference to arg into *arg.

The rationale for making the new behaviour the default is that it
simplifies the common case of "allocate some memory in decode callback".

Update issue 69
Status: FixedInGit

4 files changed, 16 insertions, 16 deletions

diff --git a/tests/decode_unittests.c b/tests/decode_unittests.c
index 039c9fa4..1e74c34d 100644
--- a/tests/decode_unittests.c
+++ b/tests/decode_unittests.c
@@ -19,11 +19,11 @@ bool stream_callback(pb_istream_t *stream, uint8_t *buf, size_t count)
 }
 
 /* Verifies that the stream passed to callback matches the byte array pointed to by arg. */
-bool callback_check(pb_istream_t *stream, const pb_field_t *field, void *arg)
+bool callback_check(pb_istream_t *stream, const pb_field_t *field, void **arg)
 {
     int i;
     uint8_t byte;
-    pb_bytes_array_t *ref = (pb_bytes_array_t*) arg;
+    pb_bytes_array_t *ref = (pb_bytes_array_t*) *arg;
     
     for (i = 0; i < ref->size; i++)
     {
diff --git a/tests/encode_unittests.c b/tests/encode_unittests.c
index 9cdbc66e..3078998e 100644
--- a/tests/encode_unittests.c
+++ b/tests/encode_unittests.c
@@ -17,7 +17,7 @@ bool streamcallback(pb_ostream_t *stream, const uint8_t *buf, size_t count)
     return true;
 }
 
-bool fieldcallback(pb_ostream_t *stream, const pb_field_t *field, const void *arg)
+bool fieldcallback(pb_ostream_t *stream, const pb_field_t *field, void * const *arg)
 {
     int value = 0x55;
     if (!pb_encode_tag_for_field(stream, field))
@@ -25,7 +25,7 @@ bool fieldcallback(pb_ostream_t *stream, const pb_field_t *field, const void *ar
     return pb_encode_varint(stream, value);
 }
 
-bool crazyfieldcallback(pb_ostream_t *stream, const pb_field_t *field, const void *arg)
+bool crazyfieldcallback(pb_ostream_t *stream, const pb_field_t *field, void * const *arg)
 {
     /* This callback writes different amount of data the second time. */
     uint32_t *state = (uint32_t*)arg;
diff --git a/tests/test_decode_callbacks.c b/tests/test_decode_callbacks.c
index 95824d1a..7ce4ec0b 100644
--- a/tests/test_decode_callbacks.c
+++ b/tests/test_decode_callbacks.c
@@ -6,7 +6,7 @@
 #include <pb_decode.h>
 #include "callbacks.pb.h"
 
-bool print_string(pb_istream_t *stream, const pb_field_t *field, void *arg)
+bool print_string(pb_istream_t *stream, const pb_field_t *field, void **arg)
 {
     uint8_t buffer[1024] = {0};
     
@@ -20,37 +20,37 @@ bool print_string(pb_istream_t *stream, const pb_field_t *field, void *arg)
     /* Print the string, in format comparable with protoc --decode.
      * Format comes from the arg defined in main().
      */
-    printf((char*)arg, buffer);
+    printf((char*)*arg, buffer);
     return true;
 }
 
-bool print_int32(pb_istream_t *stream, const pb_field_t *field, void *arg)
+bool print_int32(pb_istream_t *stream, const pb_field_t *field, void **arg)
 {
     uint64_t value;
     if (!pb_decode_varint(stream, &value))
         return false;
     
-    printf((char*)arg, (long)value);
+    printf((char*)*arg, (long)value);
     return true;
 }
 
-bool print_fixed32(pb_istream_t *stream, const pb_field_t *field, void *arg)
+bool print_fixed32(pb_istream_t *stream, const pb_field_t *field, void **arg)
 {
     uint32_t value;
     if (!pb_decode_fixed32(stream, &value))
         return false;
     
-    printf((char*)arg, (long)value);
+    printf((char*)*arg, (long)value);
     return true;
 }
 
-bool print_fixed64(pb_istream_t *stream, const pb_field_t *field, void *arg)
+bool print_fixed64(pb_istream_t *stream, const pb_field_t *field, void **arg)
 {
     uint64_t value;
     if (!pb_decode_fixed64(stream, &value))
         return false;
     
-    printf((char*)arg, (long long)value);
+    printf((char*)*arg, (long long)value);
     return true;
 }
 
diff --git a/tests/test_encode_callbacks.c b/tests/test_encode_callbacks.c
index 7fa017f9..afab48e8 100644
--- a/tests/test_encode_callbacks.c
+++ b/tests/test_encode_callbacks.c
@@ -5,7 +5,7 @@
 #include <pb_encode.h>
 #include "callbacks.pb.h"
 
-bool encode_string(pb_ostream_t *stream, const pb_field_t *field, const void *arg)
+bool encode_string(pb_ostream_t *stream, const pb_field_t *field, void * const *arg)
 {
     char *str = "Hello world!";
     
@@ -15,7 +15,7 @@ bool encode_string(pb_ostream_t *stream, const pb_field_t *field, const void *ar
     return pb_encode_string(stream, (uint8_t*)str, strlen(str));
 }
 
-bool encode_int32(pb_ostream_t *stream, const pb_field_t *field, const void *arg)
+bool encode_int32(pb_ostream_t *stream, const pb_field_t *field, void * const *arg)
 {
     if (!pb_encode_tag_for_field(stream, field))
         return false;
@@ -23,7 +23,7 @@ bool encode_int32(pb_ostream_t *stream, const pb_field_t *field, const void *arg
     return pb_encode_varint(stream, 42);
 }
 
-bool encode_fixed32(pb_ostream_t *stream, const pb_field_t *field, const void *arg)
+bool encode_fixed32(pb_ostream_t *stream, const pb_field_t *field, void * const *arg)
 {
     if (!pb_encode_tag_for_field(stream, field))
         return false;
@@ -32,7 +32,7 @@ bool encode_fixed32(pb_ostream_t *stream, const pb_field_t *field, const void *a
     return pb_encode_fixed32(stream, &value);
 }
 
-bool encode_fixed64(pb_ostream_t *stream, const pb_field_t *field, const void *arg)
+bool encode_fixed64(pb_ostream_t *stream, const pb_field_t *field, void * const *arg)
 {
     if (!pb_encode_tag_for_field(stream, field))
         return false;