Avoid linking in printf/bsearch if possible. -20k for static bbox with

"basename", "true" and "false" only.

function                                             old     new   delta
full_write2_str                                        -      25     +25
bb_show_usage                                        183     202     +19
main                                                 883     898     +15
run_applet_and_exit                                  501     507      +6
This commit is contained in:
Denis Vlasenko 2008-04-08 21:13:28 +00:00
parent 643dcf00e3
commit 79cedcb2c0
2 changed files with 83 additions and 27 deletions

View File

@ -47,6 +47,7 @@ int main(int argc, char **argv)
{
int i;
int ofs;
unsigned MAX_APPLET_NAME_LEN = 1;
qsort(applets, NUM_APPLETS, sizeof(applets[0]), cmp_name);
@ -71,18 +72,21 @@ int main(int argc, char **argv)
puts("/* This is a generated file, don't edit */\n");
printf("#define NUM_APPLETS %u\n", NUM_APPLETS);
if (NUM_APPLETS == 1) {
printf("#define SINGLE_APPLET_STR \"%s\"\n", applets[0].name);
printf("#define SINGLE_APPLET_MAIN %s_main\n\n", applets[0].name);
printf("#define SINGLE_APPLET_MAIN %s_main\n", applets[0].name);
}
puts("const char applet_names[] ALIGN1 = \"\"");
puts("\nconst char applet_names[] ALIGN1 = \"\"");
for (i = 0; i < NUM_APPLETS; i++) {
printf("\"%s\" \"\\0\"\n", applets[i].name);
if (MAX_APPLET_NAME_LEN < strlen(applets[i].name))
MAX_APPLET_NAME_LEN = strlen(applets[i].name);
}
puts(";");
puts("int (*const applet_main[])(int argc, char **argv) = {");
puts("\nint (*const applet_main[])(int argc, char **argv) = {");
for (i = 0; i < NUM_APPLETS; i++) {
printf("%s_main,\n", applets[i].main);
}
@ -113,8 +117,10 @@ int main(int argc, char **argv)
printf("0x%02x,\n", v);
i++;
}
puts("};");
puts("};\n");
#endif
printf("#define MAX_APPLET_NAME_LEN %u\n", MAX_APPLET_NAME_LEN);
return 0;
}

View File

@ -12,6 +12,21 @@
* Licensed under GPLv2 or later, see file License in this tarball for details.
*/
/* We are trying to not use printf, this benefits the case when selected
* applets are really simple. Example:
*
* $ ./busybox
* ...
* Currently defined functions:
* basename, false, true
*
* $ size busybox
* text data bss dec hex filename
* 4473 52 72 4597 11f5 busybox
*
* FEATURE_INSTALLER or FEATURE_SUID will still link printf routines in. :(
*/
#include <assert.h>
#include "busybox.h"
@ -81,6 +96,11 @@ static const char *unpack_usage_messages(void)
#endif /* FEATURE_COMPRESS_USAGE */
static void full_write2_str(const char *str)
{
full_write(2, str, strlen(str));
}
void bb_show_usage(void)
{
if (ENABLE_SHOW_USAGE) {
@ -90,18 +110,14 @@ void bb_show_usage(void)
const char *usage_string = p = unpack_usage_messages();
if (*p == '\b') {
write(2, "\nNo help available.\n\n",
sizeof("\nNo help available.\n\n") - 1);
full_write2_str("\nNo help available.\n\n");
} else {
write(2, "\nUsage: "SINGLE_APPLET_STR" ",
sizeof("\nUsage: "SINGLE_APPLET_STR" ") - 1);
write(2, p, strlen(p));
write(2, "\n\n", 2);
full_write2_str("\nUsage: "SINGLE_APPLET_STR" ");
full_write2_str(p);
full_write2_str("\n\n");
}
dealloc_usage_messages((char*)usage_string);
#else
// TODO: in this case, stdio is sucked in by busybox_main() anyway...
const char *format_string;
const char *p;
const char *usage_string = p = unpack_usage_messages();
int ap = find_applet_by_name(applet_name);
@ -112,32 +128,52 @@ void bb_show_usage(void)
while (*p++) continue;
ap--;
}
fprintf(stderr, "%s multi-call binary\n", bb_banner);
format_string = "\nUsage: %s %s\n\n";
full_write2_str(bb_banner);
full_write2_str(" multi-call binary\n");
if (*p == '\b')
format_string = "\nNo help available.\n\n";
fprintf(stderr, format_string, applet_name, p);
full_write2_str("\nNo help available.\n\n");
else {
full_write2_str("\nUsage: ");
full_write2_str(applet_name);
full_write2_str(" ");
full_write2_str(p);
full_write2_str("\n\n");
}
dealloc_usage_messages((char*)usage_string);
#endif
}
xfunc_die();
}
#if NUM_APPLETS > 8
/* NB: any char pointer will work as well, not necessarily applet_names */
static int applet_name_compare(const void *name, const void *v)
{
int i = (const char *)v - applet_names;
return strcmp(name, APPLET_NAME(i));
}
#endif
int find_applet_by_name(const char *name)
{
#if NUM_APPLETS > 8
/* Do a binary search to find the applet entry given the name. */
const char *p;
p = bsearch(name, applet_names, ARRAY_SIZE(applet_main), 1, applet_name_compare);
if (!p)
return -1;
return p - applet_names;
#else
/* A version which does not pull in bsearch */
int i = 0;
const char *p = applet_names;
while (i < NUM_APPLETS) {
if (strcmp(name, p) == 0)
return i;
p += strlen(p) + 1;
i++;
}
return -1;
#endif
}
@ -604,10 +640,11 @@ static int busybox_main(char **argv)
get_terminal_width_height(0, &output_width, NULL);
}
/* leading tab and room to wrap */
output_width -= sizeof("start-stop-daemon, ") + 8;
output_width -= MAX_APPLET_NAME_LEN + 8;
printf("%s multi-call binary\n", bb_banner); /* reuse const string... */
printf("Copyright (C) 1998-2007 Erik Andersen, Rob Landley, Denys Vlasenko\n"
full_write2_str(bb_banner); /* reuse const string... */
full_write2_str(" multi-call binary\n"
"Copyright (C) 1998-2007 Erik Andersen, Rob Landley, Denys Vlasenko\n"
"and others. Licensed under GPLv2.\n"
"See source distribution for full notice.\n"
"\n"
@ -623,14 +660,18 @@ static int busybox_main(char **argv)
col = 0;
a = applet_names;
while (*a) {
int len;
if (col > output_width) {
puts(",");
full_write2_str(",\n");
col = 0;
}
col += printf("%s%s", (col ? ", " : "\t"), a);
a += strlen(a) + 1;
full_write2_str(col ? ", " : "\t");
full_write2_str(a);
len = strlen(a);
col += len + 2;
a += len + 1;
}
puts("\n");
full_write2_str("\n\n");
return 0;
}
@ -659,7 +700,11 @@ static int busybox_main(char **argv)
* "#!/bin/busybox"-style wrappers */
applet_name = bb_get_last_path_component_nostrip(argv[0]);
run_applet_and_exit(applet_name, argv);
bb_error_msg_and_die("applet not found");
/*bb_error_msg_and_die("applet not found"); - sucks in printf */
full_write2_str(applet_name);
full_write2_str(": applet not found\n");
xfunc_die();
}
void run_applet_no_and_exit(int applet_no, char **argv)
@ -701,7 +746,8 @@ int main(int argc ATTRIBUTE_UNUSED, char **argv)
{
#if ENABLE_FEATURE_INDIVIDUAL
/* Only one applet is selected by the user! */
lbb_prepare(SINGLE_APPLET_STR USE_FEATURE_INDIVIDUAL(, argv));
/* applet_names in this case is just "applet\0\0" */
lbb_prepare(applet_names USE_FEATURE_INDIVIDUAL(, argv));
return SINGLE_APPLET_MAIN(argc, argv);
#else
lbb_prepare("busybox" USE_FEATURE_INDIVIDUAL(, argv));
@ -721,6 +767,10 @@ int main(int argc ATTRIBUTE_UNUSED, char **argv)
parse_config_file(); /* ...maybe, if FEATURE_SUID_CONFIG */
run_applet_and_exit(applet_name, argv);
bb_error_msg_and_die("applet not found");
/*bb_error_msg_and_die("applet not found"); - sucks in printf */
full_write2_str(applet_name);
full_write2_str(": applet not found\n");
xfunc_die();
#endif
}