Add struct spa_error_location that holds information about some parsing
context such as the line and column number, error and line fragment
with the error.
Make spa_json_get_error() fill in the spa_error_location instead. Add
some error codes to the error state and use this to add a parsing reason
to the location.
Add a debug function to log the error location in a nice way. Also
add a FILE based debug context to log to any FILE.
Replace pw_properties_check_string() with
pw_properties_update_string_checked() and add
pw_properties_new_string_checked(). The check string behaviour can still
be done by setting props to NULL but the main purpose is to be able to
avoid parsing the json file twice in the future.
When using the old pw_properties_update_string(), log a warning to the
log when we fail to parse the complete string.
Use the new checked functions and the debug functions to report about
parsing errors in the tools and conf parsing.
This gives errors like:
```
> pw-loopback --playback-props '{ foo = [ f : g ] }'
error: syntax error in --playback-props: Invalid array separator
line: 1 | { foo = [ f : g ] }
col: 14 | ^
```
Check each object key is associated with value. Disallow object or
array valued keys.
Add flag tracking whether the parser is at global top-level or not, as
there we may either be in object context or in a single-value context.
Save depth=0 array flag bit in state, so that spa_json_next preserves
its complete state across calls. The higher-depth flag bits can be in
temporary stack as they are not needed across calls.
Control characters probably are an error. We also are not validating any
utf8 here, so disallow bare utf8 too --- one likely should use strings
for such content anyway as spaces are not allowed otherwise.
Disallow = and : as bare items in [] containers, as that likely is
"[ { foo = bar } ]" mistyped as "[ foo = bar ]".
Disallow nesting errors, eg. "[ foo bar" or "[ foo bar }".
Fix handling of ", \ and # in bare strings.
Fix ignoring trailing comments.
Add a fixed-size stack (128 levels) to the tokenizer, so that it can
check these at levels below its depth.
When the tokenizer encounters an error, make it and its parents enter
error state where no further input will be processed. This allows caller
to check for parse errors later as convenient.
The error state can be queried using spa_json_get_error, which also
looks up the error line/column position.
spa_json_parse_float/int receive non nul-terminated string, so calling
string functions assuming nul-termination is invalid.
Fix by copying data to a buffer before doing parsing.
We need exactly 4 hex characters, everything else is refused. We
also copy those characters directly to the output string without
assuming any encoding.
See #2337
And use this in spa_json_format_float() where we also avoid invalid
json floats.
Use json float format in some places where we serialize json floats.
Add a unit test.
See #2223
