From be366e5afac1d9f5b3958bd3899a389308d5d9d3 Mon Sep 17 00:00:00 2001 From: Ron Yorston Date: Thu, 27 Jul 2017 13:53:39 +0100 Subject: [PATCH] ash: support platforms that don't have '%m' printf specifier The '%m' conversion specifier prints an error message based on the current value of 'errno'. It is available in the GNU C library, Cygwin (since 2012), uClibc and musl. It is not available in various BSDs, BSD-derived systems (MacOS, Android) or Microsoft Windows. Use a symbol defined in platform.h to control how error messages can be formatted to display the 'errno' message. On platforms that support it use '%m'; on other platforms use '%s' and strerror(). On platforms that have '%m' there is essentially no change in the size of the binary. Otherwise: function old new delta redirect 1287 1310 +23 xtcsetpgrp 27 44 +17 dup2_or_raise 34 51 +17 setinputfile 267 275 +8 .rodata 163379 163371 -8 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 4/1 up/down: 65/-8) Total: 57 bytes Signed-off-by: Ron Yorston Signed-off-by: Denys Vlasenko --- include/platform.h | 4 ++++ shell/ash.c | 22 +++++++++++++++++----- 2 files changed, 21 insertions(+), 5 deletions(-) diff --git a/include/platform.h b/include/platform.h index ea49c7e92..b81c59d4e 100644 --- a/include/platform.h +++ b/include/platform.h @@ -406,6 +406,7 @@ typedef unsigned smalluint; #define HAVE_MNTENT_H 1 #define HAVE_NET_ETHERNET_H 1 #define HAVE_SYS_STATFS_H 1 +#define HAVE_PRINTF_PERCENTM 1 #if defined(__UCLIBC__) # if UCLIBC_VERSION < KERNEL_VERSION(0, 9, 32) @@ -461,6 +462,7 @@ typedef unsigned smalluint; # undef HAVE_DPRINTF # undef HAVE_UNLOCKED_STDIO # undef HAVE_UNLOCKED_LINE_OPS +# undef HAVE_PRINTF_PERCENTM #endif #if defined(__dietlibc__) @@ -483,6 +485,7 @@ typedef unsigned smalluint; # undef HAVE_STRVERSCMP # undef HAVE_XTABS # undef HAVE_UNLOCKED_LINE_OPS +# undef HAVE_PRINTF_PERCENTM # include # if __FreeBSD_version < 1000029 # undef HAVE_STRCHRNUL /* FreeBSD added strchrnul() between 1000028 and 1000029 */ @@ -517,6 +520,7 @@ typedef unsigned smalluint; # undef HAVE_STRVERSCMP # undef HAVE_UNLOCKED_LINE_OPS # undef HAVE_NET_ETHERNET_H +# undef HAVE_PRINTF_PERCENTM #endif /* diff --git a/shell/ash.c b/shell/ash.c index 1f5a8dae0..f9c78ee78 100644 --- a/shell/ash.c +++ b/shell/ash.c @@ -1306,6 +1306,18 @@ ash_msg_and_raise_error(const char *msg, ...) va_end(ap); } +/* + * Use '%m' to append error string on platforms that support it, '%s' and + * strerror() on those that don't. + * + * 'fmt' must be a string literal. + */ +#ifdef HAVE_PRINTF_PERCENTM +#define ash_msg_and_raise_perror(fmt, ...) ash_msg_and_raise_error(fmt ": %m", ##__VA_ARGS__) +#else +#define ash_msg_and_raise_perror(fmt, ...) ash_msg_and_raise_error(fmt ": %s", ##__VA_ARGS__, strerror(errno)) +#endif + static void raise_error_syntax(const char *) NORETURN; static void raise_error_syntax(const char *msg) @@ -3827,7 +3839,7 @@ static void xtcsetpgrp(int fd, pid_t pgrp) { if (tcsetpgrp(fd, pgrp)) - ash_msg_and_raise_error("can't set tty process group (%m)"); + ash_msg_and_raise_perror("can't set tty process group"); } /* @@ -5313,7 +5325,7 @@ savefd(int from) err = newfd < 0 ? errno : 0; if (err != EBADF) { if (err) - ash_msg_and_raise_error("%d: %m", from); + ash_msg_and_raise_perror("%d", from); close(from); fcntl(newfd, F_SETFD, FD_CLOEXEC); } @@ -5328,7 +5340,7 @@ dup2_or_raise(int from, int to) newfd = (from != to) ? dup2(from, to) : to; if (newfd < 0) { /* Happens when source fd is not open: try "echo >&99" */ - ash_msg_and_raise_error("%d: %m", from); + ash_msg_and_raise_perror("%d", from); } return newfd; } @@ -5459,7 +5471,7 @@ redirect(union node *redir, int flags) /* "echo >&10" and 10 is a fd opened to a sh script? */ if (is_hidden_fd(sv, right_fd)) { errno = EBADF; /* as if it is closed */ - ash_msg_and_raise_error("%d: %m", right_fd); + ash_msg_and_raise_perror("%d", right_fd); } newfd = -1; } else { @@ -5493,7 +5505,7 @@ redirect(union node *redir, int flags) if (newfd >= 0) close(newfd); errno = i; - ash_msg_and_raise_error("%d: %m", fd); + ash_msg_and_raise_perror("%d", fd); /* NOTREACHED */ } /* EBADF: it is not open - good, remember to close it */