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2026-04-06tools/nolibc: add support for asprintf()Thomas Weißschuh1-0/+50
Add support for dynamically allocating formatted strings through asprintf() and vasprintf(). Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Acked-by: Willy Tarreau <w@1wt.eu> Link: https://patch.msgid.link/20260401-nolibc-asprintf-v1-3-46292313439f@weissschuh.net
2026-04-01tools/nolibc/printf: Support negative variable width and precisionDavid Laight1-30/+38
For (eg) "%*.*s" treat a negative field width as a request to left align the output (the same as the '-' flag), and a negative precision to request the default precision. Set the default precision to -1 (not INT_MAX) and add explicit checks to the string handling for negative values (makes the tet unsigned). For numeric output check for 'precision >= 0' instead of testing _NOLIBC_PF_FLAGS_CONTAIN(flags, '.'). This needs an inverted test, some extra goto and removes an indentation. The changed conditionals fix printf("%0-#o", 0) - but '0' and '-' shouldn't both be specified. Signed-off-by: David Laight <david.laight.linux@gmail.com> Link: https://patch.msgid.link/20260323112247.3196-1-david.laight.linux@gmail.com Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2026-03-20tools/nolibc/printf: Add support for octal outputDavid Laight1-15/+35
Octal output isn't often used, but adding it costs very little. Supporting "%#o" is mildly annoying, it has to add a leading '0' if there isn't one present. In simple cases this is the same as adding a sign of '0' - but that adds an extra '0' in a few places. So you need 3 tests, %o, # and no leading '0' (which can only be checked after the zero pad for precision). If all the test are deferred until after zero padding then too many values are 'live' across the call to _nolibc_u64toa_base() and get spilled to stack. Hence the check that ignores the 'sign' if it is the same as the first character of the output string. Add tests for octal output. Signed-off-by: David Laight <david.laight.linux@gmail.com> Acked-by: Willy Tarreau <w@1wt.eu> Link: https://patch.msgid.link/20260308113742.12649-17-david.laight.linux@gmail.com [Thomas: avoid a -Wsign-compare] Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2026-03-20tools/nolibc/printf: Add support for zero padding and field precisionDavid Laight1-16/+64
Includes support for variable field widths (eg "%*.*d"). Zero padding is limited to 31 zero characters. This is wider than the largest numeric field so shouldn't be a problem. All the standard printf formats are now supported except octal and floating point. Add tests for new features Signed-off-by: David Laight <david.laight.linux@gmail.com> Acked-by: Willy Tarreau <w@1wt.eu> Link: https://patch.msgid.link/20260308113742.12649-16-david.laight.linux@gmail.com [Thomas: fixup testcases for musl libc] Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2026-03-20tools/nolibc/printf: Add support for left aligning fieldsDavid Laight1-1/+5
Output the characters before or after the pad - writing the pad takes more code. Include additional/changed tests Signed-off-by: David Laight <david.laight.linux@gmail.com> Acked-by: Willy Tarreau <w@1wt.eu> Link: https://patch.msgid.link/20260308113742.12649-15-david.laight.linux@gmail.com Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2026-03-20tools/nolibc/printf: Special case 0 and add support for %#xDavid Laight1-11/+27
The output for %#x is almost the same as that for %p, both output in hexadecimal with a leading "0x". However for zero %#x should just output "0" (the same as decimal and ocal). For %p match glibc and output "(nil)" rather than "0x0" or "0". Add tests for "%#x", "% d", "%+d" and passing NULL to "%p". Signed-off-by: David Laight <david.laight.linux@gmail.com> Acked-by: Willy Tarreau <w@1wt.eu> Link: https://patch.msgid.link/20260308113742.12649-14-david.laight.linux@gmail.com [Thomas: fix up testcases for musl libc] Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2026-03-20tools/nolibc/printf: Add support for conversion flags space and plusDavid Laight1-1/+5
Flags ' ' and '+' are sign characters for positive numbers. Signed-off-by: David Laight <david.laight.linux@gmail.com> Acked-by: Willy Tarreau <w@1wt.eu> Link: https://patch.msgid.link/20260308113742.12649-13-david.laight.linux@gmail.com Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2026-03-20tools/nolibc/printf: Prepend sign to converted numberDavid Laight1-9/+27
Instead of appending the converted number to the sign, convert first and then prepend the sign (or "0x"). Use the length returned by u64toh_r() instead of calling strlen(). Needed so that zero padding can be inserted between the sign and digits in an upcoming patch. Signed-off-by: David Laight <david.laight.linux@gmail.com> Acked-by: Willy Tarreau <w@1wt.eu> Link: https://patch.msgid.link/20260308113742.12649-12-david.laight.linux@gmail.com Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2026-03-20tools/nolibc/printf: Handle "%s" with the numeric formatsDavid Laight1-10/+11
Avoids the extra va_arg() call with is non-trivial on a lot of modern ABI. Signed-off-by: David Laight <david.laight.linux@gmail.com> Acked-by: Willy Tarreau <w@1wt.eu> Link: https://patch.msgid.link/20260308113742.12649-11-david.laight.linux@gmail.com Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2026-03-20tools/nolibc/printf: Add support for length modifiers tzqL and formats iXDavid Laight1-11/+16
Length modifiers t (ptrdiff_t) and z (size_t) are aliases for l (long), q and L are 64bit the same as j (intmax). Format i is an alias for d and X similar to x but upper case. Supporting them is mostly just adding the relevant bit to the bit pattern used for matching characters. Although %X is detected the output will be lower case. Change/add tests to use conversions i and X, and length modifiers L and ll. Use the correct minimum value for "%Li". Signed-off-by: David Laight <david.laight.linux@gmail.com> Acked-by: Willy Tarreau <w@1wt.eu> Link: https://patch.msgid.link/20260308113742.12649-10-david.laight.linux@gmail.com [Thomas: Fix up testcases for musl libc] Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2026-03-20tools/nolibc/printf: Use bit-masks to hold requested flag, length and ↵David Laight1-48/+106
conversion chars Use flags bits (1u << (ch & 31)) for the flags, length modifiers, and conversion specifiers. This makes it easy to test for multiple values at once. Detect the conversion flags " #+-0" although they are currently all ignored. Unconditionally generate the signed values (for %d) to remove a second set of checks for the size. Separate out the formatting of single characters from numbers. Output the sign for negative values then negate and treat as unsigned. Signed-off-by: David Laight <david.laight.linux@gmail.com> Acked-by: Willy Tarreau <w@1wt.eu> Link: https://patch.msgid.link/20260308113742.12649-9-david.laight.linux@gmail.com Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2026-03-20tools/nolibc/printf: Use goto and reduce indentationDavid Laight1-78/+93
Upcoming changes will need to use goto to jump to the code that outputs characters. Use 'goto do_output' to output a known number of characters. Use 'goto do_strlen_output' to output a '\0' terminated string. Removes a level of indentation from the format processing code. The change is best reviewed using 'git diff -b' after applying it. Signed-off-by: David Laight <david.laight.linux@gmail.com> Acked-by: Willy Tarreau <w@1wt.eu> Link: https://patch.msgid.link/20260308113742.12649-8-david.laight.linux@gmail.com Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2026-03-20tools/nolibc/printf: Simplify __nolibc_printf()David Laight1-51/+53
Move the check for the length modifiers into the format processing between the field width and conversion specifier. This lets the loop be simplified and a 'fast scan' for a format start used. If an error is detected (eg an invalid conversion specifier) then copy the invalid format to the output buffer. Reduces code size by about 10% on x86-64. Some versions of gcc bloat this version by generating a jump table. All goes away in the later patches. Signed-off-by: David Laight <david.laight.linux@gmail.com> Acked-by: Willy Tarreau <w@1wt.eu> Link: https://patch.msgid.link/20260308113742.12649-7-david.laight.linux@gmail.com Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2026-03-20tools/nolibc/printf: Output pad characters in 16 byte chunksDavid Laight1-5/+9
Simple to do and saves calls to the callback function. Change variables written, width and len to 'signed int' to get better code. Signed-off-by: David Laight <david.laight.linux@gmail.com> Acked-by: Willy Tarreau <w@1wt.eu> Link: https://patch.msgid.link/20260308113742.12649-6-david.laight.linux@gmail.com Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2026-03-20tools/nolibc: Rename the 'errnum' parameter to strerror()David Laight1-2/+2
Change the parameter variable name from 'errno' to 'errnum'. Matches any documentation and avoids any issues that might happen if errno is actually a #define (which is not uncommon). Signed-off-by: David Laight <david.laight.linux@gmail.com> Acked-by: Willy Tarreau <w@1wt.eu> Link: https://patch.msgid.link/20260308113742.12649-5-david.laight.linux@gmail.com Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2026-03-20tools/nolibc: Implement strerror() in terms of strerror_r()David Laight1-3/+19
strerror() can be the only part of a program that has a .data section. This requires 4k in the program file. Add a simple implementation of strerror_r() and use that in strerror() so that the "errno=" string is copied at run-time. Use __builtin_memcpy() because that optimises away the input string and just writes the required constants to the target buffer. Code size change largely depends on whether the inlining decision for strerror() changes. Change the tests to use the normal EXPECT_VFPRINTF() when testing %m. Skip the tests when !is_nolibc. Signed-off-by: David Laight <david.laight.linux@gmail.com> Acked-by: Willy Tarreau <w@1wt.eu> Link: https://patch.msgid.link/20260308113742.12649-4-david.laight.linux@gmail.com Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2026-03-20tools/nolibc/printf: Move snprintf length check to callbackDavid Laight1-27/+67
Move output truncation to the snprintf() callback. This simplifies the main code and fixes truncation of padded fields. Add a zero length callback to 'finalise' the buffer rather than doing it in snprintf() itself. Fixes: e90ce42e81381 ("tools/nolibc: implement width padding in printf()") Signed-off-by: David Laight <david.laight.linux@gmail.com> Acked-by: Willy Tarreau <w@1wt.eu> Link: https://patch.msgid.link/20260302101815.3043-3-david.laight.linux@gmail.com [Thomas: clean up Fixes trailer] Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2026-03-20tools/nolibc/printf: Change variables 'c' to 'ch' and 'tmpbuf[]' to 'outbuf[]'David Laight1-19/+19
Changing 'c' makes the code slightly easier to read because the variable stands out from the single character literals (especially 'c'). Change tmpbuf[] to outbuf[] because 'out' points into it. The following patches pretty much rewrite the function so the churn is limited. Signed-off-by: David Laight <david.laight.linux@gmail.com> Acked-by: Willy Tarreau <w@1wt.eu> Link: https://patch.msgid.link/20260223101735.2922-7-david.laight.linux@gmail.com Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2026-01-11tools/nolibc: Add fseek() to stdio.hDaniel Palmer1-0/+19
A very basic wrapper around lseek() that implements fseek(). Signed-off-by: Daniel Palmer <daniel@thingy.jp> Link: https://patch.msgid.link/20260105023629.1502801-3-daniel@thingy.jp Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2026-01-11tools/nolibc: Add fread() to stdio.hDaniel Palmer1-1/+33
Add a very basic version of fread() like we already have for fwrite(). Signed-off-by: Daniel Palmer <daniel@thingy.jp> Link: https://patch.msgid.link/20260105023629.1502801-2-daniel@thingy.jp Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2025-10-29tools/nolibc: implement %m if errno is not definedBenjamin Berg1-2/+4
For improved compatibility, print %m as "unknown error" when nolibc is compiled using NOLIBC_IGNORE_ERRNO. Signed-off-by: Benjamin Berg <benjamin.berg@intel.com> Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2025-10-29tools/nolibc/stdio: let perror work when NOLIBC_IGNORE_ERRNO is setBenjamin Berg1-0/+4
There is no errno variable when NOLIBC_IGNORE_ERRNO is defined. As such, simply print the message with "unknown error" rather than the integer value of errno. Fixes: acab7bcdb1bc ("tools/nolibc/stdio: add perror() to report the errno value") Signed-off-by: Benjamin Berg <benjamin.berg@intel.com> Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2025-07-06selftests/nolibc: correctly report errors from printf() and friendsThomas Weißschuh1-2/+2
When an error is encountered by printf() it needs to be reported. errno() is already set by the callback. sprintf() is different, but that keeps working and is already tested. Also add a new test. Fixes: 7e4346f4a3a6 ("tools/nolibc/stdio: add a minimal [vf]printf() implementation") Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Acked-by: Willy Tarreau <w@1wt.eu> Link: https://lore.kernel.org/r/20250704-nolibc-printf-error-v1-2-74b7a092433b@linutronix.de Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2025-05-21tools/nolibc: add fopen()Thomas Weißschuh1-0/+27
This is used in various selftests and will be handy when integrating those with nolibc. Only the standard POSIX modes are supported. No extensions nor the (noop) "b" from ISO C are accepted. Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Acked-by: Willy Tarreau <w@1wt.eu> Link: https://lore.kernel.org/r/20250428-nolibc-misc-v2-13-3c043eeab06c@linutronix.de Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2025-05-21tools/nolibc: add %m printf formatThomas Weißschuh1-0/+7
The %m format can be used to format the current errno. It is non-standard but supported by other commonly used libcs like glibc and musl, so applications do rely on them. Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Acked-by: Willy Tarreau <w@1wt.eu> Link: https://lore.kernel.org/r/20250428-nolibc-misc-v2-2-3c043eeab06c@linutronix.de Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2025-05-21tools/nolibc: include nolibc.h early from all header filesThomas Weißschuh1-3/+3
Inclusion of any nolibc header file should also bring all other headers. On the other hand it should also be possible to include any nolibc header files in any order. Currently this is implemented by including the catch-all nolibc.h after the headers own definitions. This is problematic if one nolibc header depends on another one. The first header has to include the other one before defining any symbols. That in turn will include the rest of nolibc while the current header has not defined anything yet. If any other part of nolibc depends on definitions from the current header, errors are encountered. This is already the case today. Effectively nolibc can only be included in the order of nolibc.h. Restructure the way "nolibc.h" is included. Move it to the beginning of the header files and before the include guards. Now any header will behave exactly like "nolibc.h" while the include guards prevent any duplicate definitions. Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Acked-by: Willy Tarreau <w@1wt.eu> Link: https://lore.kernel.org/r/20250424-nolibc-header-check-v1-2-011576b6ed6f@linutronix.de
2025-04-22tools/nolibc: implement width padding in printf()Thomas Weißschuh1-1/+16
printf can pad each argument to a certain width. Implement this for compatibility with the kselftest harness. Currently only padding with spaces is supported. Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Acked-by: Willy Tarreau <w@1wt.eu>
2025-04-22tools/nolibc: add snprintf() and friendsThomas Weißschuh1-0/+55
Add more of the printf() functions. Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Acked-by: Willy Tarreau <w@1wt.eu>
2025-04-22tools/nolibc: allow limiting of printf destination sizeThomas Weißschuh1-6/+10
snprintf() allows limiting the output buffer, while still returning the number of all bytes that would have been written. Implement the limitation logic in preparation for snprintf(). Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Acked-by: Willy Tarreau <w@1wt.eu>
2025-04-22tools/nolibc: allow different write callbacks in printfThomas Weißschuh1-4/+17
Decouple the formatting logic from the writing logic to later enable writing straight to a buffer in sprintf(). Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Acked-by: Willy Tarreau <w@1wt.eu>
2025-04-22tools/nolibc: add dprintf() and vdprintf()Thomas Weißschuh1-0/+24
dprintf() and vdprintf() are printf() variants printing directly into a filedescriptor. As FILE in nolibc is based directly on filedescriptors, the implementation is trivial. Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Acked-by: Willy Tarreau <w@1wt.eu>
2025-04-22tools/nolibc: handle intmax_t/uintmax_t in printfThomas Weißschuh1-0/+2
In nolibc intmax_t and uintmax_t are always the same as (unsigned) long long/uint64_t as 128bit numbers are not supported. Even libcs that do support 128bit numbers often fix intmax_t to 64bit as it is used in ABIs and any change would break those. Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Acked-by: Willy Tarreau <w@1wt.eu>
2025-02-26tools/nolibc: add support for [v]sscanf()Thomas Weißschuh1-0/+98
These functions are used often, also in selftests. sscanf() itself is also used by kselftest.h itself. The implementation is limited and only supports numeric arguments. Acked-by: Willy Tarreau <w@1wt.eu> Link: https://lore.kernel.org/r/20250209-nolibc-scanf-v2-1-c29dea32f1cd@weissschuh.net Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2024-10-07tools/nolibc: compiler: add macro __nolibc_fallthroughThomas Weißschuh1-1/+2
Recent version of GCC and clang gained -Wimplicit-fallthrough, warning about implicit fall-through between switch labels. As nolibc does not control the compilation flags, this can trigger warnings for when built by the user. Make use of the "fallthrough" attribute to explicitly annotate the expected fall-throughs and silence the warning. Link: https://lore.kernel.org/r/20240930-nolibc-fallthrough-v2-1-2e8d10fe3430@weissschuh.net Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2024-06-29tools/nolibc: implement strerror()Thomas Weißschuh1-0/+10
strerror() is commonly used. For example in kselftest which currently needs to do an #ifdef NOLIBC to handle the lack of strerror(). Keep it simple and reuse the output format of perror() for strerror(). Acked-by: Shuah Khan <skhan@linuxfoundation.org> Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2023-12-11tools/nolibc: annotate va_list printf formatsThomas Weißschuh1-2/+2
__attribute__(format(printf)) can also be used for functions that take a va_list argument. As per the GCC docs: For functions where the arguments are not available to be checked (such as vprintf), specify the third parameter as zero. Link: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
2023-10-12tools/nolibc: add stdarg.h headerThomas Weißschuh1-2/+1
This allows nolic to work with `-nostdinc` avoiding any reliance on system headers. The implementation has been lifted from musl libc 1.2.4. There is already an implementation of stdarg.h in include/linux/stdarg.h but that is GPL licensed and therefore not suitable for nolibc. The used compiler builtins have been validated to be at least available since GCC 4.1.2 and clang 3.0.0. Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Signed-off-by: Willy Tarreau <w@1wt.eu>
2023-08-23tools/nolibc: setvbuf: avoid unused parameter warningsThomas Weißschuh1-1/+4
This warning will be enabled later so avoid triggering it. Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Signed-off-by: Willy Tarreau <w@1wt.eu>
2023-08-23tools/nolibc/stdio: add setvbuf() to set buffering modeRyan Roberts1-0/+24
Add a minimal implementation of setvbuf(), which error checks the mode argument (as required by spec) and returns. Since nolibc never buffers output, nothing needs to be done. The kselftest framework recently added a call to setvbuf(). As a result, any tests that use the kselftest framework and nolibc cause a compiler error due to missing function. This provides an urgent fix for the problem which is preventing arm64 testing on linux-next. Example: clang --target=aarch64-linux-gnu -fintegrated-as -Werror=unknown-warning-option -Werror=ignored-optimization-argument -Werror=option-ignored -Werror=unused-command-line-argument --target=aarch64-linux-gnu -fintegrated-as -fno-asynchronous-unwind-tables -fno-ident -s -Os -nostdlib \ -include ../../../../include/nolibc/nolibc.h -I../..\ -static -ffreestanding -Wall za-fork.c build/kselftest/arm64/fp/za-fork-asm.o -o build/kselftest/arm64/fp/za-fork In file included from <built-in>:1: In file included from ./../../../../include/nolibc/nolibc.h:97: In file included from ./../../../../include/nolibc/arch.h:25: ./../../../../include/nolibc/arch-aarch64.h:178:35: warning: unknown attribute 'optimize' ignored [-Wunknown-attributes] void __attribute__((weak,noreturn,optimize("omit-frame-pointer"))) __no_stack_protector _start(void) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ In file included from za-fork.c:12: ../../kselftest.h:123:2: error: call to undeclared function 'setvbuf'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration] setvbuf(stdout, NULL, _IOLBF, 0); ^ ../../kselftest.h:123:24: error: use of undeclared identifier '_IOLBF' setvbuf(stdout, NULL, _IOLBF, 0); ^ 1 warning and 2 errors generated. Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Reported-by: Linux Kernel Functional Testing <lkft@linaro.org> Link: https://lore.kernel.org/linux-kselftest/CA+G9fYus3Z8r2cg3zLv8uH8MRrzLFVWdnor02SNr=rCz+_WGVg@mail.gmail.com/ Reviewed-by: Mark Brown <broonie@kernel.org> Signed-off-by: Willy Tarreau <w@1wt.eu>
2023-06-09tools/nolibc: implement fd-based FILE streamsThomas Weißschuh1-27/+68
This enables the usage of the stream APIs with arbitrary filedescriptors. It will be used by a future testcase. Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-04-11tools/nolibc/stdio: Implement vprintf()Mark Brown1-0/+6
vprintf() is equivalent to vfprintf() to stdout so implement it as a simple wrapper for the existing vfprintf(), allowing us to build kselftest.h. Suggested-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Mark Brown <broonie@kernel.org> Acked-by: Willy Tarreau <w@1wt.eu> Acked-by: Paul E. McKenney <paulmck@kernel.org> Acked-by: Shuah Khan <skhan@linuxfoundation.org> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2023-01-09tools/nolibc: fix missing includes causing build issues at -O0Willy Tarreau1-0/+3
After the nolibc includes were split to facilitate portability from standard libcs, programs that include only what they need may miss some symbols which are needed by libgcc. This is the case for raise() which is needed by the divide by zero code in some architectures for example. Regardless, being able to include only the apparently needed files is convenient. Instead of trying to move all exported definitions to a single file, since this can change over time, this patch takes another approach consisting in including the nolibc header at the end of all standard include files. This way their types and functions are already known at the moment of inclusion, and including any single one of them is sufficient to bring all the required ones. Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-06-20tools/nolibc/stdio: Add format attribute to enable printf warningsAlviro Iskandar Setiawan1-2/+2
When we use printf and fprintf functions from the nolibc, we don't get any warning from the compiler if we have the wrong arguments. For example, the following calls will compile silently: ``` printf("%s %s\n", "aaa"); fprintf(stdout, "%s %s\n", "xxx", 1); ``` (Note the wrong arguments). Those calls are undefined behavior. The compiler can help us warn about the above mistakes by adding a `printf` format attribute to those functions declaration. This patch adds it, and now it yields these warnings for those mistakes: ``` warning: format `%s` expects a matching `char *` argument [-Wformat=] warning: format `%s` expects argument of type `char *`, but argument 4 has type `int` [-Wformat=] ``` [ ammarfaizi2: Simplify the attribute placement. ] Signed-off-by: Alviro Iskandar Setiawan <alviro.iskandar@gnuweeb.org> Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org> Acked-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20tools/nolibc/stdio: add support for '%p' to vfprintf()Willy Tarreau1-11/+19
%p remains quite useful in test code, and the code path can easily be merged with the existing "%x" thus only adds ~50 bytes, thus let's add it. Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20tools/nolibc/stdio: make printf(%s) accept NULLWilly Tarreau1-0/+2
It's often convenient to support this, especially in test programs where a NULL may correspond to an allocation error or a non-existing value. Let's make printf("%s") support being passed a NULL. In this case it prints "(null)" like glibc's printf(). Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20tools/nolibc/errno: extract errno.h from sys.hWilly Tarreau1-0/+1
This allows us to provide a minimal errno.h to ease porting applications that use it. Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20tools/nolibc/stdio: add perror() to report the errno valueWilly Tarreau1-0/+6
It doesn't contain the text for the error codes, but instead displays "errno=" followed by the errno value. Just like the regular errno, if a non-empty message is passed, it's placed followed with ": " on the output before the errno code. The message is emitted on stderr. Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20tools/nolibc/stdio: add a minimal [vf]printf() implementationWilly Tarreau1-0/+128
This adds a minimal vfprintf() implementation as well as the commonly used fprintf() and printf() that rely on it. For now the function supports: - formats: %s, %c, %u, %d, %x - modifiers: %l and %ll - unknown chars are considered as modifiers and are ignored It is designed to remain minimalist, despite this printf() is 549 bytes on x86_64. It would be wise not to add too many formats. Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20tools/nolibc/stdio: add fwrite() to stdioWilly Tarreau1-7/+28
We'll use it to write substrings. It relies on a simpler _fwrite() that only takes one size. fputs() was also modified to rely on it. Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20tools/nolibc/stdio: add stdin/stdout/stderr and fget*/fput* functionsWilly Tarreau1-6/+89
The standard puts() function always emits the trailing LF which makes it unconvenient for small string concatenation. fputs() ought to be used instead but it requires a FILE*. This adds 3 dummy FILE* values (stdin, stdout, stderr) which are in fact pointers to struct FILE of one byte. We reserve 3 pointer values for them, -3, -2 and -1, so that they are ordered, easing the tests and mapping to integer. >From this, fgetc(), fputc(), fgets() and fputs() were implemented, and the previous putchar() and getchar() now remap to these. The standard getc() and putc() macros were also implemented as pointing to these ones. There is absolutely no buffering, fgetc() and fgets() read one byte at a time, fputc() writes one byte at a time, and only fputs() which knows the string's length writes all of it at once. Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>