From: Ryan Roberts Date: Wed, 26 Jul 2023 07:06:55 +0000 (+0100) Subject: tools/nolibc/stdio: add setvbuf() to set buffering mode X-Git-Tag: v6.6.17~4111^2~32 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=4893c22eb2f4364bc037e9451dfc3bd36a231901;p=platform%2Fkernel%2Flinux-rpi.git tools/nolibc/stdio: add setvbuf() to set buffering mode 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 :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 Reported-by: Linux Kernel Functional Testing Link: https://lore.kernel.org/linux-kselftest/CA+G9fYus3Z8r2cg3zLv8uH8MRrzLFVWdnor02SNr=rCz+_WGVg@mail.gmail.com/ Reviewed-by: Mark Brown Signed-off-by: Willy Tarreau --- diff --git a/tools/include/nolibc/stdio.h b/tools/include/nolibc/stdio.h index 0eef91d..a3778af 100644 --- a/tools/include/nolibc/stdio.h +++ b/tools/include/nolibc/stdio.h @@ -21,6 +21,11 @@ #define EOF (-1) #endif +/* Buffering mode used by setvbuf. */ +#define _IOFBF 0 /* Fully buffered. */ +#define _IOLBF 1 /* Line buffered. */ +#define _IONBF 2 /* No buffering. */ + /* just define FILE as a non-empty type. The value of the pointer gives * the FD: FILE=~fd for fd>=0 or NULL for fd<0. This way positive FILE * are immediately identified as abnormal entries (i.e. possible copies @@ -350,6 +355,25 @@ void perror(const char *msg) fprintf(stderr, "%s%serrno=%d\n", (msg && *msg) ? msg : "", (msg && *msg) ? ": " : "", errno); } +static __attribute__((unused)) +int setvbuf(FILE *stream, char *buf, int mode, size_t size) +{ + /* + * nolibc does not support buffering so this is a nop. Just check mode + * is valid as required by the spec. + */ + switch (mode) { + case _IOFBF: + case _IOLBF: + case _IONBF: + break; + default: + return EOF; + } + + return 0; +} + /* make sure to include all global symbols */ #include "nolibc.h"