This converts to TEST macro where it is trivial.
Some additional notable changes:
- simplify HAVE_LIBIDN #ifdef in test-dns-domain.c
- use saved_argc/saved_argv in test-copy.c, test-path-util.c,
test-tmpfiles.c and test-unit-file.c
This macro is like JSON_BUILD_STRING() but uses our json library's
ability to use literal strings directly as JsonVariant objects.
The changes all our codebase to use this new macro whenever we build
JSON objects from literal strings.
(I tried to make this automatic, i.e. to detect in JSON_BUILD_STRING()
whether something is a literal string nicely and thus do this stuff
automatically, but I couldn't find a way.)
This should reduce memory usage of our JSON code a bit. Constant strings
we use very often will now be shared and mapped directly from the ELF
image.
The rest of our JSON code tries hard to magically convert NULL inputs
into "null" JSON objects, let's make sure this also works with
json_variant_set_field().
We were already asserting that the intmax_t and uintmax_t types
are the same as int64_t and uint64_t. Pretty much everywhere in
the code base we use the latter types. In principle intmax_t could
be something different on some new architecture, and then the code would
fail to compile or behave differently. We actually do not want the code
to behave differently on those architectures, because that'd break
interoperability. So let's just use int64_t/uint64_t since that's what
we indend to use.
It seems that the implementation of long double on ppc64el doesn't really work:
long double cast to integer and back compares as unequal to itself. Strangely,
this effect happens without optimization and both with gcc and clang, so it
seems to be an effect of how long double is implemented by the architecture.
Dumping the values shows the following pattern:
00 00 00 00 00 00 24 40 00 00 00 00 00 00 00 00 # long double v = 10;
00 00 00 00 00 00 24 40 00 00 00 00 00 00 80 39 # (long double)(intmax_t) v
Instead of trying to make this work, I think it's most reasonable to switch to
normal doubles. Notably, we had no tests for floating point behaviour. The
first test we added (for values even not in the range outside of double),
showed failures.
Common implementations of JSON (in particular JavaScript) use 64 bit double.
If we stick to this, users are likely to be happy when they exchange data with
those tools. Exporting values that cannot be represented in other tools would
just cause interop problems.
I don't think the extra precision would be much used. Long double seems to make
most sense as a transient format used in calculations to get extra precision in
operations, and not a storage or exchange format. So I expect low-level
numerical routines that have to know about hardware to make use of it, but it
shouldn't be used by our (higher-level) system library. In particular, we would
have to add tests for implementations conforming to IEEE 754, and those that
don't conform, and account for various implementation differences. It just
doesn't seem worth the effort.
https://en.wikipedia.org/wiki/Long_double#Implementations shows that the
situation is "complicated":
> On the x86 architecture, most C compilers implement long double as the 80-bit
> extended precision type supported by x86 hardware. An exception is Microsoft
> Visual C++ for x86, which makes long double a synonym for double. The Intel
> C++ compiler on Microsoft Windows supports extended precision, but requires
> the /Qlong‑double switch for long double to correspond to the hardware's
> extended precision format.
> Compilers may also use long double for the IEEE 754 quadruple-precision
> binary floating-point format (binary128). This is the case on HP-UX,
> Solaris/SPARC, MIPS with the 64-bit or n32 ABI, 64-bit ARM (AArch64) (on
> operating systems using the standard AAPCS calling conventions, such as
> Linux), and z/OS with FLOAT(IEEE). Most implementations are in software, but
> some processors have hardware support.
> On some PowerPC and SPARCv9 machines, long double is implemented as a
> double-double arithmetic, where a long double value is regarded as the exact
> sum of two double-precision values, giving at least a 106-bit precision; with
> such a format, the long double type does not conform to the IEEE
> floating-point standard. Otherwise, long double is simply a synonym for
> double (double precision), e.g. on 32-bit ARM, 64-bit ARM (AArch64) (on
> Windows and macOS) and on 32-bit MIPS (old ABI, a.k.a. o32).
> With the GNU C Compiler, long double is 80-bit extended precision on x86
> processors regardless of the physical storage used for the type (which can be
> either 96 or 128 bits). On some other architectures, long double can be
> double-double (e.g. on PowerPC) or 128-bit quadruple precision (e.g. on
> SPARC). As of gcc 4.3, a quadruple precision is also supported on x86, but as
> the nonstandard type __float128 rather than long double.
> Although the x86 architecture, and specifically the x87 floating-point
> instructions on x86, supports 80-bit extended-precision operations, it is
> possible to configure the processor to automatically round operations to
> double (or even single) precision. Conversely, in extended-precision mode,
> extended precision may be used for intermediate compiler-generated
> calculations even when the final results are stored at a lower precision
> (i.e. FLT_EVAL_METHOD == 2). With gcc on Linux, 80-bit extended precision is
> the default; on several BSD operating systems (FreeBSD and OpenBSD),
> double-precision mode is the default, and long double operations are
> effectively reduced to double precision. (NetBSD 7.0 and later, however,
> defaults to 80-bit extended precision). However, it is possible to override
> this within an individual program via the FLDCW "floating-point load
> control-word" instruction. On x86_64, the BSDs default to 80-bit extended
> precision. Microsoft Windows with Visual C++ also sets the processor in
> double-precision mode by default, but this can again be overridden within an
> individual program (e.g. by the _controlfp_s function in Visual C++). The
> Intel C++ Compiler for x86, on the other hand, enables extended-precision
> mode by default. On IA-32 OS X, long double is 80-bit extended precision.
So, in short, the only thing that can be said is that nothing can be said. In
common scenarios, we are getting only a bit of extra precision (80 bits instead
of 64), but use space for padding. In other scenarios we are getting no extra
precision. And the variance in implementations is a big issue: we can expect
strange differences in behaviour between architectures, systems, compiler
versions, compilation options, and even the other things that the program is
doing.
Fixes#21390.
JSON strings must be utf-8-clean. We also verify this in json_parse_string()
so we would reject a message with invalid utf-8 anyway.
It would probably be slightly cheaper to detect non-conformaning strings in
serialization, but then we'd have to fail serialization. By doing this early,
we give the caller a chance to handle the error nicely.
The test is adjusted to contain a valid utf-8 string after decoding of the
utf-32 encoding in json ("विवेकख्यातिरविप्लवा हानोपायः।", something about the
cessation of ignorance).
Let's add a concept of normalization: as preparation for signing json
records let's add a mechanism to bring JSON records into a well-defined
order so that we can safely validate JSON records.
This adds two booleans to each JsonVariant object: "sorted" and
"normalized". The latter indicates whether a variant is fully sorted
(i.e. all keys of objects listed in alphabetical order) recursively down
the tree. The former is a weaker property: it only checks whether the
keys of the object itself are sorted. All variants which are
"normalized" are also "sorted", but not vice versa.
The knowledge of the "sorted" property is then used to optimize
searching for keys in the variant by using bisection.
Both properties are determined at the moment the variants are allocated.
Since our objects are immutable this is safe.
This will call json_variant_sensitive() internally while parsing for
each allocated sub-variant. This is better than calling it a posteriori
at the end, because partially parsed variants will always be properly
erased from memory this way.
Should finally fix oss-fuzz-14688.
8688c29b5a wasn't enough.
The buffer retrieved from memstream has the size that the same as the written
data. When we write do write(f, s, strlen(s)), then no terminating NUL is written,
and the buffer is not (necessarilly) a proper C string.
Fixes#11600.
The code was effectively doing:
json_build(..., ({ char **_x = ((char**) ((const char*[]) {"one", "two", "three", "four", NULL })); _x; }));
but there was no guarantee that the storage for the array that _x points to
survives pass the end of the block. Essentially, STRV_MAKE cannot be used
inline inside of a block like this.
Found by inspecting results of running this small program:
int main(int argc, const char **argv) {
for (int i = 1; i < argc; i++) {
FILE *f;
char line[1024], prev[1024], *r;
int lineno;
prev[0] = '\0';
lineno = 1;
f = fopen(argv[i], "r");
if (!f)
exit(1);
do {
r = fgets(line, sizeof(line), f);
if (!r)
break;
if (strcmp(line, prev) == 0)
printf("%s:%d: error: dup %s", argv[i], lineno, line);
lineno++;
strcpy(prev, line);
} while (!feof(f));
fclose(f);
}
}
The test fails under valgrind, so there was an exception for valgrind.
Unfortunately that check only works when valgrind-devel headers are
available during build. But it is possible to have just valgrind installed,
or simply install it after the build, and then "valgrind test-json" would
fail.
It also seems that even without valgrind, this fails on some arm32 CPUs.
Let's do the usual-style test for absolute and relative differences.
Quite often when we generate objects some fields should only be
generated in some conditions. Let's add high-level support for that.
Matching the existing JSON_BUILD_PAIR() this adds
JSON_BUILD_PAIR_CONDITIONAL() which is very similar, but takes an
additional parameter: a boolean condition. If "true" this acts like
JSON_BUILD_PAIR(), but if false then the whole pair is suppressed.
This sounds simply, but requires a tiny bit of complexity: when complex
sub-variants are used in fields, then we also need to suppress them.
This is a nice little optimization when using static const strings: we
can now use them directly as JsonVariant objecs, without any additional
allocation.
Simply as a safety precaution so that json objects we read are not
arbitrary amounts deep, so that code that processes json objects
recursively can't be easily exploited (by hitting stack limits).
Follow-up for oss-fuzz#10908
(Nice is that we can accomodate for this counter without increasing the
size of the JsonVariant object.)
This was used by the dkr logic, which is gone now, hence remove this too.
Should we need it one day again the git history never forgets...
Note that this only covers the JSON parser. The JSON generator used by
"journalctl -o json" remains, as its much much simpler and requires no
infrastructure except printf() and the most basic escaping.
There are more than enough calls doing string manipulations to deserve
its own files, hence do something about it.
This patch also sorts the #include blocks of all files that needed to be
updated, according to the sorting suggestions from CODING_STYLE. Since
pretty much every file needs our string manipulation functions this
effectively means that most files have sorted #include blocks now.
Also touches a few unrelated include files.
This patch removes includes that are not used. The removals were found with
include-what-you-use which checks if any of the symbols from a header is
in use.
We originally only supported escaping ucs2 encoded characters (as \uxxxx). This
only covers the BMP. Support escaping also utf16 surrogate pairs (on the form
\uxxxx\uyyyy) to cover all of unicode.
