Thanks to Basile Starynkevitch for the suggestion and initial patch.
Thanks to Jonathan Landis and Deron Meranda for showing how this can
be utilized for implementing secure memory operations.
Functions taking va_args are munged to receive arguments of type
'__va_list_tag *'. This patch uses va_copy to coerce them to the expected type
so we don't get compiler errors.
Tested on x86_64, both 32-bit and 64-bit compiles.
Reported-By: Basile Starynkevitch <basile@starynkevitch.net>
Now, by default, unpacking doesn't check that all array and object
items are accessed. The check can be enabled globally by using the
JSON_STRICT flag (formerly JSON_UNPACK_ONLY), or on a per-value basis
by using the new '!' format character. The '*' format character is
still available to disable the global check on a per-value basis.
Expand the pack/unpack API: json_(un)pack is the simple version with
no error output, json_(un)pack_ex has error output and flags,
json_v(un)pack_ex is a va_list version of json_(un)pack_ex.
Implement unpacking flags:
- JSON_UNPACK_ONLY turns off extra validation, i.e. array and object
unpacking doesn't check that all items are unpacked. This is really
just convenience for not adding '*' after each object and array.
- JSON_VALIDATE_ONLY turns off unpacking, i.e. no varargs are expected
and nothing is unpacked.
* By default, json_unpack() now checks that all items of arrays and
objects are unpacked. This is useful for validation.
* Add format specifier '*' to suppress this check for individual
arrays and objects. '*' must appear as the last format specifier
before the closing ']' or '}'.
* Use the format string scanner from the previous commit (with the
simpler separator skipping semantics)
* Split json_vnunpack() to three separate functions for unpacking
objects, arrays and "simple" values
* Always return 0 on success, 1 on error
This shaves around 100 more lines from the original implementation.
* Implement a "scanner" that reads the format string, maintaining state
* Split json_vnpack() to three separate functions for packing objects,
arrays and simple values. This makes it more clear what is being
packed, and the object and array structures become more evident.
* Make the skipping of ignored character simpler, i.e. skip ':' and
',' independent of their context
This patch shaves around 80 lines of code from the original
implementation.
Note that we pass va_list pointers around instead of just va_lists, which
would seem more intuitive. This is necessary since the behaviour of va_lists
passed as function parameters is finicky. Quoth stdarg(3):
If ap is passed to a function that uses va_arg(ap,type) then the value
of ap is undefined after the return of that function.
The pointer-passing strategy is used by Python's Py_BuildValue() for the same
purpose.
This patch adds two new fields to the json_error_t struct: column and
source. It also adds functions to populate json_error_t internally.
The column field is not currently used, but it will be utilized in the
decoder and pack/unpack functions.
After looking at the new code for a few days, I didn't like it
anymore. To prepare for the future, a few fields will be added to the
json_error_t struct later.
This reverts commit 23dd078c8d. Some
adjustments were needed because of newer commits.
All decoding functions now accept a json_error_t** parameter and set
it to point to a heap-allocated json_error_t structure if an error
occurs. The contents of json_error_t are no longer exposed directly, a
few functions to do it have been added instead. If an error occurs,
the user must free the json_error_t value.
This makes it possible to enhance the error reporting facilities in
the future without breaking ABI compatibility with older versions.
This is a backwards incompatible change.
As of now, the parameter is unused, but may be needed in the future.
I'm adding it now so that in the future both API and ABI remain
backwards compatible as long as possible.
This is a backwards incompatible change.
This is to free up bits from the flags parameter of json_dump
functions. I'm pretty sure no-one needs 256 spaces of indentation when
pretty-printing JSON values...
This is a backwards incompatible change.
json_int_t is typedef'd to long long if it's supported, or long
otherwise. There's also some supporting things, like the
JSON_INTEGER_FORMAT macro that expands to the printf() conversion
specifier that corresponds to json_int_t's actual type.
This is a backwards incompatible change.
Replace all occurences of unsigned int and unsigned long with size_t.
This is a backwards incompatible change, as the signature of many API
functions changes.
When encoding an array or object ends in an error, the visited flag
wasn't zeroed, causing subsequent encoding attempts to fail. This
patch fixes the problem by always zeroing the visited flag.
Encoding an empty array or object worked, but encoding it again
(possibly after adding some items) failed, because the visited flag
(used for detecting circular references) wasn't zeroed.
