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mirror of https://git.tartarus.org/simon/putty.git synced 2025-01-09 09:27:59 +00:00
putty-source/misc.h
Simon Tatham 3214563d8e Convert a lot of 'int' variables to 'bool'.
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'!
2018-11-03 13:45:00 +00:00

259 lines
8.7 KiB
C

/*
* Header for misc.c.
*/
#ifndef PUTTY_MISC_H
#define PUTTY_MISC_H
#include "defs.h"
#include "puttymem.h"
#include "marshal.h"
#include <stdio.h> /* for FILE * */
#include <stdarg.h> /* for va_list */
#include <time.h> /* for struct tm */
unsigned long parse_blocksize(const char *bs);
char ctrlparse(char *s, char **next);
size_t host_strcspn(const char *s, const char *set);
char *host_strchr(const char *s, int c);
char *host_strrchr(const char *s, int c);
char *host_strduptrim(const char *s);
char *dupstr(const char *s);
char *dupcat(const char *s1, ...);
char *dupprintf(const char *fmt, ...)
#ifdef __GNUC__
__attribute__ ((format (printf, 1, 2)))
#endif
;
char *dupvprintf(const char *fmt, va_list ap);
void burnstr(char *string);
struct strbuf {
char *s;
unsigned char *u;
int len;
BinarySink_IMPLEMENTATION;
/* (also there's a surrounding implementation struct in misc.c) */
};
strbuf *strbuf_new(void);
void strbuf_free(strbuf *buf);
void *strbuf_append(strbuf *buf, size_t len);
char *strbuf_to_str(strbuf *buf); /* does free buf, but you must free result */
void strbuf_catf(strbuf *buf, const char *fmt, ...);
void strbuf_catfv(strbuf *buf, const char *fmt, va_list ap);
strbuf *strbuf_new_for_agent_query(void);
void strbuf_finalise_agent_query(strbuf *buf);
/* String-to-Unicode converters that auto-allocate the destination and
* work around the rather deficient interface of mb_to_wc.
*
* These actually live in miscucs.c, not misc.c (the distinction being
* that the former is only linked into tools that also have the main
* Unicode support). */
wchar_t *dup_mb_to_wc_c(int codepage, int flags, const char *string, int len);
wchar_t *dup_mb_to_wc(int codepage, int flags, const char *string);
int toint(unsigned);
char *fgetline(FILE *fp);
char *chomp(char *str);
bool strstartswith(const char *s, const char *t);
bool strendswith(const char *s, const char *t);
void base64_encode_atom(const unsigned char *data, int n, char *out);
int base64_decode_atom(const char *atom, unsigned char *out);
struct bufchain_granule;
struct bufchain_tag {
struct bufchain_granule *head, *tail;
int buffersize; /* current amount of buffered data */
IdempotentCallback *ic;
};
void bufchain_init(bufchain *ch);
void bufchain_clear(bufchain *ch);
int bufchain_size(bufchain *ch);
void bufchain_add(bufchain *ch, const void *data, int len);
void bufchain_prefix(bufchain *ch, void **data, int *len);
void bufchain_consume(bufchain *ch, int len);
void bufchain_fetch(bufchain *ch, void *data, int len);
void bufchain_fetch_consume(bufchain *ch, void *data, int len);
bool bufchain_try_fetch_consume(bufchain *ch, void *data, int len);
void sanitise_term_data(bufchain *out, const void *vdata, int len);
bool validate_manual_hostkey(char *key);
struct tm ltime(void);
/*
* Special form of strcmp which can cope with NULL inputs. NULL is
* defined to sort before even the empty string.
*/
int nullstrcmp(const char *a, const char *b);
ptrlen make_ptrlen(const void *ptr, size_t len);
ptrlen ptrlen_from_asciz(const char *str);
ptrlen ptrlen_from_strbuf(strbuf *sb);
bool ptrlen_eq_string(ptrlen pl, const char *str);
bool ptrlen_eq_ptrlen(ptrlen pl1, ptrlen pl2);
bool ptrlen_startswith(ptrlen whole, ptrlen prefix, ptrlen *tail);
char *mkstr(ptrlen pl);
int string_length_for_printf(size_t);
/* Derive two printf arguments from a ptrlen, suitable for "%.*s" */
#define PTRLEN_PRINTF(pl) \
string_length_for_printf((pl).len), (const char *)(pl).ptr
/* Make a ptrlen out of a compile-time string literal. We try to
* enforce that it _is_ a string literal by token-pasting "" on to it,
* which should provoke a compile error if it's any other kind of
* string. */
#define PTRLEN_LITERAL(stringlit) \
TYPECHECK("" stringlit "", make_ptrlen(stringlit, sizeof(stringlit)-1))
/* Wipe sensitive data out of memory that's about to be freed. Simpler
* than memset because we don't need the fill char parameter; also
* attempts (by fiddly use of volatile) to inhibit the compiler from
* over-cleverly trying to optimise the memset away because it knows
* the variable is going out of scope. */
void smemclr(void *b, size_t len);
/* Compare two fixed-length chunks of memory for equality, without
* data-dependent control flow (so an attacker with a very accurate
* stopwatch can't try to guess where the first mismatching byte was).
* Returns false for mismatch or true for equality (unlike memcmp),
* hinted at by the 'eq' in the name. */
bool smemeq(const void *av, const void *bv, size_t len);
char *buildinfo(const char *newline);
/*
* Debugging functions.
*
* Output goes to debug.log
*
* debug(()) (note the double brackets) is like printf().
*
* dmemdump() and dmemdumpl() both do memory dumps. The difference
* is that dmemdumpl() is more suited for when the memory address is
* important (say because you'll be recording pointer values later
* on). dmemdump() is more concise.
*/
#ifdef DEBUG
void debug_printf(const char *fmt, ...);
void debug_memdump(const void *buf, int len, bool L);
#define debug(x) (debug_printf x)
#define dmemdump(buf,len) debug_memdump (buf, len, false);
#define dmemdumpl(buf,len) debug_memdump (buf, len, true);
#else
#define debug(x)
#define dmemdump(buf,len)
#define dmemdumpl(buf,len)
#endif
#ifndef lenof
#define lenof(x) ( (sizeof((x))) / (sizeof(*(x))))
#endif
#ifndef min
#define min(x,y) ( (x) < (y) ? (x) : (y) )
#endif
#ifndef max
#define max(x,y) ( (x) > (y) ? (x) : (y) )
#endif
#define GET_64BIT_LSB_FIRST(cp) \
(((uint64_t)(unsigned char)(cp)[0]) | \
((uint64_t)(unsigned char)(cp)[1] << 8) | \
((uint64_t)(unsigned char)(cp)[2] << 16) | \
((uint64_t)(unsigned char)(cp)[3] << 24) | \
((uint64_t)(unsigned char)(cp)[4] << 32) | \
((uint64_t)(unsigned char)(cp)[5] << 40) | \
((uint64_t)(unsigned char)(cp)[6] << 48) | \
((uint64_t)(unsigned char)(cp)[7] << 56))
#define PUT_64BIT_LSB_FIRST(cp, value) ( \
(cp)[0] = (unsigned char)(value), \
(cp)[1] = (unsigned char)((value) >> 8), \
(cp)[2] = (unsigned char)((value) >> 16), \
(cp)[3] = (unsigned char)((value) >> 24), \
(cp)[4] = (unsigned char)((value) >> 32), \
(cp)[5] = (unsigned char)((value) >> 40), \
(cp)[6] = (unsigned char)((value) >> 48), \
(cp)[7] = (unsigned char)((value) >> 56) )
#define GET_32BIT_LSB_FIRST(cp) \
(((uint32_t)(unsigned char)(cp)[0]) | \
((uint32_t)(unsigned char)(cp)[1] << 8) | \
((uint32_t)(unsigned char)(cp)[2] << 16) | \
((uint32_t)(unsigned char)(cp)[3] << 24))
#define PUT_32BIT_LSB_FIRST(cp, value) ( \
(cp)[0] = (unsigned char)(value), \
(cp)[1] = (unsigned char)((value) >> 8), \
(cp)[2] = (unsigned char)((value) >> 16), \
(cp)[3] = (unsigned char)((value) >> 24) )
#define GET_16BIT_LSB_FIRST(cp) \
(((unsigned long)(unsigned char)(cp)[0]) | \
((unsigned long)(unsigned char)(cp)[1] << 8))
#define PUT_16BIT_LSB_FIRST(cp, value) ( \
(cp)[0] = (unsigned char)(value), \
(cp)[1] = (unsigned char)((value) >> 8) )
#define GET_32BIT_MSB_FIRST(cp) \
(((uint32_t)(unsigned char)(cp)[0] << 24) | \
((uint32_t)(unsigned char)(cp)[1] << 16) | \
((uint32_t)(unsigned char)(cp)[2] << 8) | \
((uint32_t)(unsigned char)(cp)[3]))
#define GET_32BIT(cp) GET_32BIT_MSB_FIRST(cp)
#define PUT_32BIT_MSB_FIRST(cp, value) ( \
(cp)[0] = (unsigned char)((value) >> 24), \
(cp)[1] = (unsigned char)((value) >> 16), \
(cp)[2] = (unsigned char)((value) >> 8), \
(cp)[3] = (unsigned char)(value) )
#define PUT_32BIT(cp, value) PUT_32BIT_MSB_FIRST(cp, value)
#define GET_64BIT_MSB_FIRST(cp) \
(((uint64_t)(unsigned char)(cp)[0] << 56) | \
((uint64_t)(unsigned char)(cp)[1] << 48) | \
((uint64_t)(unsigned char)(cp)[2] << 40) | \
((uint64_t)(unsigned char)(cp)[3] << 32) | \
((uint64_t)(unsigned char)(cp)[4] << 24) | \
((uint64_t)(unsigned char)(cp)[5] << 16) | \
((uint64_t)(unsigned char)(cp)[6] << 8) | \
((uint64_t)(unsigned char)(cp)[7]))
#define PUT_64BIT_MSB_FIRST(cp, value) ( \
(cp)[0] = (unsigned char)((value) >> 56), \
(cp)[1] = (unsigned char)((value) >> 48), \
(cp)[2] = (unsigned char)((value) >> 40), \
(cp)[3] = (unsigned char)((value) >> 32), \
(cp)[4] = (unsigned char)((value) >> 24), \
(cp)[5] = (unsigned char)((value) >> 16), \
(cp)[6] = (unsigned char)((value) >> 8), \
(cp)[7] = (unsigned char)(value) )
#define GET_16BIT_MSB_FIRST(cp) \
(((unsigned long)(unsigned char)(cp)[0] << 8) | \
((unsigned long)(unsigned char)(cp)[1]))
#define PUT_16BIT_MSB_FIRST(cp, value) ( \
(cp)[0] = (unsigned char)((value) >> 8), \
(cp)[1] = (unsigned char)(value) )
/* Replace NULL with the empty string, permitting an idiom in which we
* get a string (pointer,length) pair that might be NULL,0 and can
* then safely say things like printf("%.*s", length, NULLTOEMPTY(ptr)) */
#define NULLTOEMPTY(s) ((s)?(s):"")
#endif