I've added the gcc-style attribute("printf") to a lot of printf-shaped
functions in this code base that didn't have it. To make that easier,
I moved the wrapping macro into defs.h, and also enabled it if we
detect the __clang__ macro as well as __GNU__ (hence, it will be used
when building for Windows using clang-cl).
The result is that a great many format strings in the code are now
checked by the compiler, where they were previously not. This causes
build failures, which I'll fix in the next commit.
When I'm declaring a local instance of some context structure type to
pass to a function which will pass it in turn to a callback, I've
tended to use a declaration of the form
struct context actx, *ctx = &actx;
so that the outermost caller can initialise the context, and/or read
out fields of it afterwards, by the same syntax 'ctx->foo' that the
callback function will be using. So you get visual consistency between
the two functions that share this context.
It only just occurred to me that there's a much neater way to declare
a context struct of this kind, which still makes 'ctx' behave like a
pointer in the owning function, and doesn't need all that weird
verbiage or a spare variable name:
struct context ctx[1];
That's much nicer! I've switched to doing that in all existing cases I
could find, and also in a couple of cases where I hadn't previously
bothered to do the previous more cumbersome idiom.
The number of people has been steadily increasing who read our source
code with an editor that thinks tab stops are 4 spaces apart, as
opposed to the traditional tty-derived 8 that the PuTTY code expects.
So I've been wondering for ages about just fixing it, and switching to
a spaces-only policy throughout the code. And I recently found out
about 'git blame -w', which should make this change not too disruptive
for the purposes of source-control archaeology; so perhaps now is the
time.
While I'm at it, I've also taken the opportunity to remove all the
trailing spaces from source lines (on the basis that git dislikes
them, and is the only thing that seems to have a strong opinion one
way or the other).
Apologies to anyone downstream of this code who has complicated patch
sets to rebase past this change. I don't intend it to be needed again.
This fixes a batch of clang-analyzer warnings of the form 'you
declared / assigned this variable and then never use it'. It doesn't
fix _all_ of them - some are there so that when I add code in the
future _it_ can use the variable without me having to remember to
start setting it - but these are the ones I thought it would make the
code better instead of worse to fix.
My normal habit these days, in new code, is to treat int and bool as
_almost_ completely separate types. I'm still willing to use C's
implicit test for zero on an integer (e.g. 'if (!blob.len)' is fine,
no need to spell it out as blob.len != 0), but generally, if a
variable is going to be conceptually a boolean, I like to declare it
bool and assign to it using 'true' or 'false' rather than 0 or 1.
PuTTY is an exception, because it predates the C99 bool, and I've
stuck to its existing coding style even when adding new code to it.
But it's been annoying me more and more, so now that I've decided C99
bool is an acceptable thing to require from our toolchain in the first
place, here's a quite thorough trawl through the source doing
'boolification'. Many variables and function parameters are now typed
as bool rather than int; many assignments of 0 or 1 to those variables
are now spelled 'true' or 'false'.
I managed this thorough conversion with the help of a custom clang
plugin that I wrote to trawl the AST and apply heuristics to point out
where things might want changing. So I've even managed to do a decent
job on parts of the code I haven't looked at in years!
To make the plugin's work easier, I pushed platform front ends
generally in the direction of using standard 'bool' in preference to
platform-specific boolean types like Windows BOOL or GTK's gboolean;
I've left the platform booleans in places they _have_ to be for the
platform APIs to work right, but variables only used by my own code
have been converted wherever I found them.
In a few places there are int values that look very like booleans in
_most_ of the places they're used, but have a rarely-used third value,
or a distinction between different nonzero values that most users
don't care about. In these cases, I've _removed_ uses of 'true' and
'false' for the return values, to emphasise that there's something
more subtle going on than a simple boolean answer:
- the 'multisel' field in dialog.h's list box structure, for which
the GTK front end in particular recognises a difference between 1
and 2 but nearly everything else treats as boolean
- the 'urgent' parameter to plug_receive, where 1 vs 2 tells you
something about the specific location of the urgent pointer, but
most clients only care about 0 vs 'something nonzero'
- the return value of wc_match, where -1 indicates a syntax error in
the wildcard.
- the return values from SSH-1 RSA-key loading functions, which use
-1 for 'wrong passphrase' and 0 for all other failures (so any
caller which already knows it's not loading an _encrypted private_
key can treat them as boolean)
- term->esc_query, and the 'query' parameter in toggle_mode in
terminal.c, which _usually_ hold 0 for ESC[123h or 1 for ESC[?123h,
but can also hold -1 for some other intervening character that we
don't support.
In a few places there's an integer that I haven't turned into a bool
even though it really _can_ only take values 0 or 1 (and, as above,
tried to make the call sites consistent in not calling those values
true and false), on the grounds that I thought it would make it more
confusing to imply that the 0 value was in some sense 'negative' or
bad and the 1 positive or good:
- the return value of plug_accepting uses the POSIXish convention of
0=success and nonzero=error; I think if I made it bool then I'd
also want to reverse its sense, and that's a job for a separate
piece of work.
- the 'screen' parameter to lineptr() in terminal.c, where 0 and 1
represent the default and alternate screens. There's no obvious
reason why one of those should be considered 'true' or 'positive'
or 'success' - they're just indices - so I've left it as int.
ssh_scp_recv had particularly confusing semantics for its previous int
return value: its call sites used '<= 0' to check for error, but it
never actually returned a negative number, just 0 or 1. Now the
function and its call sites agree that it's a bool.
In a couple of places I've renamed variables called 'ret', because I
don't like that name any more - it's unclear whether it means the
return value (in preparation) for the _containing_ function or the
return value received from a subroutine call, and occasionally I've
accidentally used the same variable for both and introduced a bug. So
where one of those got in my way, I've renamed it to 'toret' or 'retd'
(the latter short for 'returned') in line with my usual modern
practice, but I haven't done a thorough job of finding all of them.
Finally, one amusing side effect of doing this is that I've had to
separate quite a few chained assignments. It used to be perfectly fine
to write 'a = b = c = TRUE' when a,b,c were int and TRUE was just a
the 'true' defined by stdbool.h, that idiom provokes a warning from
gcc: 'suggest parentheses around assignment used as truth value'!
This is a thing I've been meaning to set up for a while: it's a
pull-based search system (that is, the caller takes each step of the
search manually, rather than providing a callback), which lets the
caller inspect every step of the search, including the index of each
candidate element in the tree. This allows flexible kinds of query
that play the element and its index off against each other.
I've also rewritten the existing findrelpos234() search function using
the new one as a primitive, because that simplifies it a lot!
Added a missing #include of string.h; arranged that the test program
reports the number of errors detected at the end so I don't have to
search its entire output for "ERROR"; made the test program return a
nonzero exit status if any error was found.
Oops - I found this in an editor autosave file after pushing the
previous commit. I meant it to be part of the previous commit. Oh
well, better late than never.
(Since we choose to compile with -Werror, this is particularly important.)
I haven't yet checked that the resulting source actually compiles cleanly with
GCC 4, hence not marking `gcc4-warnings' as fixed just yet.
[originally from svn r7041]
malloc functions, which automatically cast to the same type they're
allocating the size of. Should prevent any future errors involving
mallocing the size of the wrong structure type, and will also make
life easier if we ever need to turn the PuTTY core code from real C
into C++-friendly C. I haven't touched the Mac frontend in this
checkin because I couldn't compile or test it.
[originally from svn r3014]
smalloc() macros and thence to the safemalloc() functions in misc.c.
This should allow me to plug in a debugging allocator and track
memory leaks and segfaults and things.
[originally from svn r818]
can do that. The bad case happens when you have a root node containing
only one actual element, and its two child nodes have only one element
each, and you try to delete the element in the root.
[originally from svn r660]
