This macro will read a pointer of any type, return it, and set the
pointer to NULL. This is useful as an explicit concept of passing
ownership of a memory area between pointers.
This takes inspiration from Rust:
https://doc.rust-lang.org/std/option/enum.Option.html#method.take
and was suggested by Alan Jenkins (@sourcejedi).
It drops ~160 lines of code from our codebase, which makes me like it.
Also, I think it clarifies passing of ownership, and thus helps
readability a bit (at least for the initiated who know the new macro)
../src/basic/extract-word.c:255:22: warning: passing an object that undergoes default argument promotion to 'va_start' has undefined behavior [-Wvarargs]
va_start(ap, flags);
^
../src/basic/extract-word.c:244:77: note: parameter of type 'ExtractFlags' (aka 'enum ExtractFlags') is declared here
int extract_many_words(const char **p, const char *separators, ExtractFlags flags, ...) {
^
../src/basic/extract-word.c:286:22: warning: passing an object that undergoes default argument promotion to 'va_start' has undefined behavior [-Wvarargs]
va_start(ap, flags);
^
../src/basic/extract-word.c:244:77: note: parameter of type 'ExtractFlags' (aka 'enum ExtractFlags') is declared here
int extract_many_words(const char **p, const char *separators, ExtractFlags flags, ...) {
^
2 warnings generated.
I think the relevant part of C99 is 6.7.2.2 Enumeration specifiers:
Each enumerated type shall be compatible with char, a signed integer type, or
an unsigned integer type. The choice of type is implementation-defined, but
shall be capable of representing the values of all the members of the
enumeration.
and 7.16.1.4:
The parameter parmN is the identifier of the rightmost parameter in the
variable parameter list in the function definition (the one just before the
...). If the parameter parmN is declared with the register storage class, with
a function or array type, or with a type that is not compatible with the type
that results after application of the default argument promotions, the behavior
is undefined.
This might cause a real issue if the compiler chooses something that is not an
integer for ExtractFlags. Rework the code to avoid the warning, but add an
assert_cc in a large-valued ExtractFlags element is ever defined and the type
is bumped to something wider than an int.
Our warning message was misleading, because we wouldn't "correct" anything,
we'd just ignore unkown escapes. Update the message.
Also, print just the extracted word (which contains the offending sequences) in
the message, instead of the whole line.
Fixes#4697.
Throughout the tree there's spurious use of spaces separating ++ and --
operators from their respective operands. Make ++ and -- operator
consistent with the majority of existing uses; discard the spaces.
rework C11 utf8.[ch] to use char32_t instead of uint32_t when referring
to unicode chars, to make things more expressive.
[
@zonque:
* rebased to current master
* use AC_CHECK_DECLS to detect availibility of char{16,32}_t
* make utf8_encoded_to_unichar() return int
]
Not every byte sequence is valid utf8. We allow escaping of non-utf8
sequences in strings by using octal and hexadecimal escape sequences
(\123 and \0xAB) for bytes at or above 128. Users of cunescape_one
could infer whether such use occured when they received an answer
between 128 and 256 in *ret (a non-ascii one byte character). But this
is subtle and misleading: the comments were wrong, because ascii is a
subset of unicode, so c != 0 did not mean non-unicode, but rather
ascii-subset-of-unicode-or-raw-byte. This was all rather confusing, so
make the "single byte" condition explicit.
I'm not convinced that allowing non-utf8 sequences to be produced is
useful in all cases where we allow it (e.g. in config files), but that
behaviour is unchanged, just made more explicit.
This also fixes an (invalid) gcc warning about unitialized variable
(*ret_unicode) in callers of cunescape_one.
3d793d2905 broke parsing of unit file
names that include backslashes, as extract_first_word() strips those.
Fix this, by introducing a new EXTRACT_RETAIN_ESCAPE flag which disables
looking at any flags, thus being compatible with the classic
FOREACH_WORD() behaviour.
Just skip them in place, instead of setting separator=true. We only do
that in a single place (while finding a separator outside of quote or
backslash states) so we don't really need a separate state for it.
Tested that no regressions were introduced in test-extract-word. Ran a
full `make check` and also installed the binaries on a test system and
did not see any issues related to parsing unit files or starting units
after a reboot.
Use inner loops to keep processing the same state, except when there is
a state change, then break back to the outer loop so that the correct
branch can be selected again.
Tested that no regressions were introduced in test-extract-word.
This will make it easier to use inner loops to keep looping in the same
state, by just updating p and c in the same way in the inner loops.
Tested that no regressions were created in test-extract-word.
Using `goto` might be appropriate for the "finish" cases but it was
really not necessary at this point of the code... Just use if/else
blocks to accomplish the same.
Confirmed that the test cases in test-extract-word keep working as
expected.
This block runs once before all the other handling, so move it outside
the main loop and put it in its own loop until it's finished doing its
job.
Tested by confirming `make check` (and particularly test-extract-word)
still passes and by booting a system with binaries including this
commit.
- Really warn in all error cases, not just some. We need to make sure
that all errors are logged to not confuse the user.
- Explicitly check for EINVAL error code before claiming anything about
invalid escapes, could be ENOMEM after all.
Lennart Poettering