path: root/networking/udhcp/common.h
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authorGravatar James Byrne <james.byrne@origamienergy.com>2019-07-02 11:35:03 +0200
committerGravatar Denys Vlasenko <vda.linux@googlemail.com>2019-07-02 11:35:03 +0200
commit6937487be73cd4563b876413277a295a5fe2f32c (patch)
treef16cc9999a7c827891e6ec8d99c699fc791008ee /networking/udhcp/common.h
parentcaecfdc20d450686cd1f7e9b5f650322f894b3c2 (diff)
libbb: reduce the overhead of single parameter bb_error_msg() calls
Back in 2007, commit 0c97c9d43707 ("'simple' error message functions by Loic Grenie") introduced bb_simple_perror_msg() to allow for a lower overhead call to bb_perror_msg() when only a string was being printed with no parameters. This saves space for some CPU architectures because it avoids the overhead of a call to a variadic function. However there has never been a simple version of bb_error_msg(), and since 2007 many new calls to bb_perror_msg() have been added that only take a single parameter and so could have been using bb_simple_perror_message(). This changeset introduces 'simple' versions of bb_info_msg(), bb_error_msg(), bb_error_msg_and_die(), bb_herror_msg() and bb_herror_msg_and_die(), and replaces all calls that only take a single parameter, or use something like ("%s", arg), with calls to the corresponding 'simple' version. Since it is likely that single parameter calls to the variadic functions may be accidentally reintroduced in the future a new debugging config option WARN_SIMPLE_MSG has been introduced. This uses some macro magic which will cause any such calls to generate a warning, but this is turned off by default to avoid use of the unpleasant macros in normal circumstances. This is a large changeset due to the number of calls that have been replaced. The only files that contain changes other than simple substitution of function calls are libbb.h, libbb/herror_msg.c, libbb/verror_msg.c and libbb/xfuncs_printf.c. In miscutils/devfsd.c, networking/udhcp/common.h and util-linux/mdev.c additonal macros have been added for logging so that single parameter and multiple parameter logging variants exist. The amount of space saved varies considerably by architecture, and was found to be as follows (for 'defconfig' using GCC 7.4): Arm: -92 bytes MIPS: -52 bytes PPC: -1836 bytes x86_64: -938 bytes Note that for the MIPS architecture only an exception had to be made disabling the 'simple' calls for 'udhcp' (in networking/udhcp/common.h) because it made these files larger on MIPS. Signed-off-by: James Byrne <james.byrne@origamienergy.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Diffstat (limited to 'networking/udhcp/common.h')
1 files changed, 19 insertions, 0 deletions
diff --git a/networking/udhcp/common.h b/networking/udhcp/common.h
index bba3d6037..60255eefa 100644
--- a/networking/udhcp/common.h
+++ b/networking/udhcp/common.h
@@ -267,26 +267,45 @@ struct option_set *udhcp_find_option(struct option_set *opt_list, uint8_t code)
# define IF_UDHCP_VERBOSE(...) __VA_ARGS__
extern unsigned dhcp_verbose;
# define log1(...) do { if (dhcp_verbose >= 1) bb_info_msg(__VA_ARGS__); } while (0)
+# define log1s(msg) do { if (dhcp_verbose >= 1) bb_simple_info_msg(msg); } while (0)
void udhcp_dump_packet(struct dhcp_packet *packet) FAST_FUNC;
# define log2(...) do { if (dhcp_verbose >= 2) bb_info_msg(__VA_ARGS__); } while (0)
+# define log2s(msg) do { if (dhcp_verbose >= 2) bb_simple_info_msg(msg); } while (0)
# else
# define udhcp_dump_packet(...) ((void)0)
# define log2(...) ((void)0)
+# define log2s(msg) ((void)0)
# endif
# define log3(...) do { if (dhcp_verbose >= 3) bb_info_msg(__VA_ARGS__); } while (0)
+# define log3s(msg) do { if (dhcp_verbose >= 3) bb_simple_info_msg(msg); } while (0)
# else
# define log3(...) ((void)0)
+# define log3s(msg) ((void)0)
# endif
# define IF_UDHCP_VERBOSE(...)
# define udhcp_dump_packet(...) ((void)0)
# define log1(...) ((void)0)
+# define log1s(msg) ((void)0)
# define log2(...) ((void)0)
+# define log2s(msg) ((void)0)
# define log3(...) ((void)0)
+# define log3s(msg) ((void)0)
+#if defined(__mips__)
+ * The 'simple' message functions have a negative impact on the size of the
+ * DHCP code when compiled for MIPS, so don't use them in this case.
+ */
+#define bb_simple_info_msg bb_info_msg
+#define bb_simple_error_msg bb_error_msg
+#define bb_simple_perror_msg_and_die bb_perror_msg_and_die
+#undef log1s
+#define log1s log1
/*** Other shared functions ***/