path: root/src/stdio
AgeCommit message (Collapse)AuthorLines
2012-06-19stdio: handle file position correctly at program exitRich Felker-3/+35
for seekable files, posix imposed requirements on the offset of the underlying open file description after a stream is closed. this was correctly handled (as a side effect of the unconditional fflush call) when streams were explicitly closed by fclose, but was not handled correctly at program exit time, where fflush(0) was being used. the weak symbol hackery is to pull in __stdio_exit if either of __toread or __towrite is used, but avoid calling it twice so we don't have to keep extra state. the new __stdio_exit is a streamlined fflush variant that avoids performing any unnecessary operations and which never unlocks the files or open file list, so we can be sure no other threads write new data to a stream's buffer after it's already flushed.
2012-06-19minor cleanup in fflushRich Felker-5/+1
2012-06-19remove flush hook cruft that was never used from stdioRich Felker-4/+0
there is no need/use for a flush hook. the write function serves this purpose already. i originally created the hook for implementing mem streams based on a mistaken reading of posix, and later realized it wasn't useful but never removed it until now.
2012-06-17change stdio_ext __freading/__fwriting semantics slightlyRich Felker-2/+2
the old behavior was to only consider a stream to be "reading" or "writing" if it had buffered, unread/unwritten data. this reportedly differs from the traditional behavior of these functions, which is essentially to return true as much as possible without creating the possibility that both __freading and __fwriting could return true. gnulib expects __fwriting to return true as soon as a file is opened write-only, and possibly expects other cases that depend on the traditional behavior. and since these functions exist mostly for gnulib (does anything else use them??), they should match the expected behavior to avoid even more ugly hacks and workarounds...
2012-06-17fdopen should set errno when it fails due to invalid mode stringRich Felker-1/+4
2012-06-08fix %ls breakage in last printf fixRich Felker-2/+2
signedness issue kept %ls with no precision from working at all
2012-06-08fix printf %ls with precision limit over-read issueRich Felker-2/+2
printf was not printing too many characters, but it was reading one too many wchar_t elements from the input. this could lead to crashes if running off the page, or spurious failure if the conversion of the extra wchar_t resulted in EILSEQ.
2012-06-07fix scanf bug reading literals after width-limited fieldRich Felker-0/+1
the field width limit was not being cleared before reading the literal, causing spurious failures in scanf in cases like "%2d:" scanning "00:".
2012-06-02add some ugly aliases for LSB ABI compatibilityRich Felker-0/+8
for some nonsensical reason, glibc's headers use inline functions that redirect some of the standard functions to ugly nonstandard names (and likewise for some of their nonstandard functions).
2012-05-25avoid using pthread cleanup push/pop in stdio when not neededRich Felker-6/+14
unfortunately in dynamic-linked programs, these macros cause pthread_self to be initialized, which costs a couple syscalls, and (much worse) would necessarily fail, crash, and burn on ancient (2.4 and earlier) kernels where setting up a thread pointer does not work. i'd like to do this in a more generic way that avoids all use of cleanup push/pop before pthread_self has been successfully called and avoids ugly if/else constructs like the one in this commit, but for now, this will suffice.
2012-05-04fix uninitialized var in vfwprintf printing 0-prec stringRich Felker-1/+1
this could lead to spurious failures of wide printf functions
2012-04-19fix really bad breakage in strtol, etc.: failure to accept leading spacesRich Felker-1/+1
2012-04-17fix wide scanf's handling of input failure on %c, and simplify %[Rich Felker-5/+6
2012-04-17fix failure to distinguish input/match failure in wide %[ scanfRich Felker-2/+4
this also includes a related fix for vswscanf's read function, which was returning a spurious (uninitialized) character for empty strings.
2012-04-17fix over-read in %ls with non-wide scanfRich Felker-0/+1
2012-04-17fix broken %s and %[ with no width specifier in wide scanfRich Felker-3/+7
2012-04-17make wide scanf %[ respect widthRich Felker-2/+3
2012-04-17fix wide scanf to respect field width for stringsRich Felker-4/+7
2012-04-17fix some bugs in scanf %[ handling detected while writing the wide versionRich Felker-4/+4
2012-04-17introduce new wide scanf code and remove the last remnants of old scanfRich Felker-524/+312
at this point, strto* and all scanf family functions are using the new unified integer and floating point parser/converter code. the wide scanf is largely a wrapper for ordinary byte-based scanf; since numbers can only contain ascii characters, only strings need to be handled specially.
2012-04-17avoid depending on POSIX symbol in code used from plain C functionsRich Felker-1/+3
2012-04-17avoid null pointer dereference on %*p fields in scanfRich Felker-1/+1
2012-04-17also ensure that write buffer is bounded when __stdio_write returnsRich Felker-0/+1
assuming other code is correct, this should be a no-op, but better to be safe...
2012-04-17fix buffer overflow in vfprintf on long writes to unbuffered filesRich Felker-1/+2
vfprintf temporarily swaps in a local buffer (for the duration of the operation) when the target stream is unbuffered; this both simplifies the implementation of functions like dprintf (they don't need their own buffers) and eliminates the pathologically bad performance of writing the formatted output with one or more write syscalls per formatting field. in cases like dprintf where we are dealing with a virgin FILE structure, everything worked correctly. however for long-lived files (like stderr), it's possible that the buffer bounds were already set for the internal zero-size buffer. on the next write, __stdio_write would pick up and use the new buffer provided by vfprintf, but the bound (wend) field was still pointing at the internal zero-size buffer's end. this in turn allowed unbounded writes to the temporary buffer.
2012-04-16fix %lf, etc. with printfRich Felker-0/+2
the l prefix is redundant/no-op with printf, since default promotions always promote floats to double; however, it is valid, and printf was wrongly rejecting it.
2012-04-16new scanf implementation and corresponding integer parser/converterRich Felker-30/+343
advantages over the old code: - correct results for floating point (old code was bogus) - wide/regular scanf separated so scanf does not pull in wide code - well-defined behavior on integers that overflow dest type - support for %[a-b] ranges with %[ (impl-defined by widely used) - no intermediate conversion of fmt string to wide string - cleaner, easier to share code with strto* functions - better standards conformance for corner cases the old code remains in the source tree, as the wide versions of the scanf-family functions are still using it. it will be removed when no longer needed.
2012-03-13fix scanf handling of "0" (followed by immediate EOF) with "%x"Rich Felker-11/+6
other cases with %x were probably broken too. I would actually like to go ahead and replace this code in scanf with calls to the new __intparse framework, but for now this calls for a quick and unobtrusive fix without the risk of breaking other things.
2012-02-02make stdio open, read, and write operations cancellation pointsRich Felker-5/+28
it should be noted that only the actual underlying buffer flush and fill operations are cancellable, not reads from or writes to the buffer. this behavior is compatible with POSIX, which makes all cancellation points in stdio optional, and it achieves the goal of allowing cancellation of a thread that's "stuck" on IO (due to a non-responsive socket/pipe peer, slow/stuck hardware, etc.) without imposing any measurable performance cost.
2011-10-14simplify atexit and fflush-on-exit handlingRich Felker-1/+4
2011-09-28don't crash on null strings in printfRich Felker-1/+1
passing null pointer for %s is UB but lots of broken programs do it anyway
2011-09-21avoid setting FILE lock count when not using flockfileRich Felker-1/+1
for now this is just a tiny optimization, but later if we support cancellation from __stdio_read and __stdio_write, it will be necessary for the recusrive lock count to be zero in order for these functions to know they are responsible for unlocking the FILE on cancellation.
2011-09-04more fmemopen null termination fixesRich Felker-2/+3
null termination is only added when current size grows. in update modes, null termination is not added if it does not fit (i.e. it is not allowed to clobber data). these rules make very little sense, but that's how it goes..
2011-09-04fix some fmemopen behaviorsRich Felker-4/+7
read should not be allowed past "current size". append mode should write at "current size", not buffer size. null termination should not be written except when "current size" grows.
2011-09-04fmemopen: fix eof handling, hopefully right this timeRich Felker-3/+4
2011-09-04fmemopen fixesRich Felker-1/+3
disallow seek past end of buffer (per posix) fix position accounting to include data buffered for read don't set eof flag when no data was requested
2011-09-04memstreams: fix incorrect handling of file pos > current sizeRich Felker-4/+4
the addition is safe and cannot overflow because both operands are positive when considered as signed quantities.
2011-09-04optimize seek function for memory streamsRich Felker-24/+6
2011-09-04fix twos complement overflow bug in mem streams boundary checkRich Felker-2/+2
the expression -off is not safe in case off is the most-negative value. instead apply - to base which is known to be non-negative and bounded within sanity.
2011-09-03implement fmemopenRich Felker-18/+66
testing so far has been minimal. may need further work.
2011-09-03fix some length calculations in memory streamsRich Felker-3/+3
2011-09-03implement open_wmemstreamRich Felker-0/+95
not heavily tested, but it seems to be correct, including the odd behavior that seeking is in terms of wide character count. this precludes any simple buffering, so we just make the stream unbuffered.
2011-09-03implement open_memstreamRich Felker-0/+94
this is the first attempt, and may have bugs. only minimal testing has been performed.
2011-08-01fix crash in dns code with new stdio locking codeRich Felker-0/+1
2011-07-30add proper fuxed-based locking for stdioRich Felker-39/+44
previously, stdio used spinlocks, which would be unacceptable if we ever add support for thread priorities, and which yielded pathologically bad performance if an application attempted to use flockfile on a key file as a major/primary locking mechanism. i had held off on making this change for fear that it would hurt performance in the non-threaded case, but actually support for recursive locking had already inflicted that cost. by having the internal locking functions store a flag indicating whether they need to perform unlocking, rather than using the actual recursive lock counter, i was able to combine the conditionals at unlock time, eliminating any additional cost, and also avoid a nasty corner case where a huge number of calls to ftrylockfile could cause deadlock later at the point of internal locking. this commit also fixes some issues with usage of pthread_self conflicting with __attribute__((const)) which resulted in crashes with some compiler versions/optimizations, mainly in flockfile prior to pthread_create.
2011-07-30eliminate dependence of perror on printfRich Felker-10/+5
2011-07-16fix logic error in freadRich Felker-6/+1
fread was calling f->read without checking that the file was in reading mode. this could: 1. crash, if f->read was a null pointer 2. cause unwanted blocking on a terminal already at eof 3. allow reading on a write-only file
2011-07-04printf: "if a precision is specified, the '0' flag shall be ignored."Rich Felker-1/+1
2011-07-04zero precision with zero value should not inhibit prefix/width printingRich Felker-1/+4
2011-07-04printf("%#x",0) should print 0 not 0x0Rich Felker-1/+1
2011-06-30fix logic in __fwritingRich Felker-1/+1