diff options
| -rw-r--r-- | Makefile.am | 2 | ||||
| -rw-r--r-- | bits.c | 77 | ||||
| -rw-r--r-- | bits.h | 42 |
3 files changed, 120 insertions, 1 deletions
diff --git a/Makefile.am b/Makefile.am index 727bda5b..528b099d 100644 --- a/Makefile.am +++ b/Makefile.am @@ -14,7 +14,7 @@ INCLUDES = $(DBUS_CFLAGS) endif bin_PROGRAMS = $(BUILD_PROGS) sirfmon -check_PROGRAMS = gpsmm_test +check_PROGRAMS = gpsmm_test bits bin_SCRIPTS = gpsprof gpsfake # @@ -0,0 +1,77 @@ +/* test harness for bits.h */ + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include "bits.h" + +int main (int argc, char *argv[]) + +{ + unsigned char buf[80]; + union int_float i_f; + union long_double l_d; + char sb1,sb2; + unsigned char ub1,ub2; + short sw1,sw2; + unsigned short uw1,uw2; + int sl1,sl2; + unsigned int ul1,ul2; + long long sL1,sL2; + unsigned long long uL1,uL2; + float f1; + double d1; + + memcpy(buf,"\x01\x02\x03\x04\x05\x06\x07\x08",8); + memcpy(buf+8,"\xff\xfe\xfd\xfc\xfb\xfa\xf9\xf8",8); + memcpy(buf+16,"\x40\x09\x21\xfb\x54\x44\x2d\x18",8); + memcpy(buf+24,"\x40\x49\x0f\xdb",4); + + sb1 = getsb(0); + sb2 = getsb(8); + ub1 = getub(0); + ub2 = getub(8); + sw1 = getsw(0); + sw2 = getsw(8); + uw1 = getuw(0); + uw2 = getuw(8); + sl1 = getsl(0); + sl2 = getsl(8); + ul1 = getul(0); + ul2 = getul(8); + sL1 = getsL(0); + sL2 = getsL(8); + uL1 = getuL(0); + uL2 = getuL(8); + f1 = getf(24); + d1 = getd(16); + + printf("getsb: %016llx %016llx %016llx %016llx\n", + (unsigned long long)sb1, (unsigned long long)sb2, + (unsigned long long)getsb(0), (unsigned long long)getsb(8)); + printf("getub: %016llx %016llx %016llx %016llx\n", + (unsigned long long)ub1, (unsigned long long)ub2, + (unsigned long long)getub(0), (unsigned long long)getub(8)); + printf("getsw: %016llx %016llx %016llx %016llx\n", + (unsigned long long)sw1, (unsigned long long)sw2, + (unsigned long long)getsw(0), (unsigned long long)getsw(8)); + printf("getuw: %016llx %016llx %016llx %016llx\n", + (unsigned long long)uw1, (unsigned long long)uw2, + (unsigned long long)getuw(0), (unsigned long long)getuw(8)); + printf("getsl: %016llx %016llx %016llx %016llx\n", + (unsigned long long)sl1, (unsigned long long)sl2, + (unsigned long long)getsl(0), (unsigned long long)getsl(8)); + printf("getul: %016llx %016llx %016llx %016llx\n", + (unsigned long long)ul1, (unsigned long long)ul2, + (unsigned long long)getul(0), (unsigned long long)getul(8)); + printf("getsL: %016llx %016llx %016llx %016llx\n", + (unsigned long long)sL1, (unsigned long long)sL2, + (unsigned long long)getsL(0), (unsigned long long)getsL(8)); + printf("getuL: %016llx %016llx %016llx %016llx\n", + (unsigned long long)uL1, (unsigned long long)uL2, + (unsigned long long)getuL(0), (unsigned long long)getuL(8)); + printf("getf: %f %f\n", f1, getf(24)); + printf("getd: %.16f %.16f\n", d1, getd(16)); + + exit(0); +} @@ -0,0 +1,42 @@ +/* + * bits.h - extract binary data from message buffer + * + * these macros extract bytes, words, longwords, floats or doubles from + * a message that contains these items in MSB-first byte order. + * + * the macros access a local buffer named "buf" which must be declared + * as unsigned char buf[SIZE]; + * + * assumptions: + * char is 8 bits, short is 16 bits, int is 32 bits, long long is 64 bits, + * float is 32 bits IEEE754, double is 64 bits IEEE754. + * + * it would be possible to use types like int16_t from header files to enforce + * these assumptions, but splint does not understand those and will scream. + * also, using such explicitly sized types usually causes warnings at many + * other places in a program (like when calling library routines). we will + * need to consider this again when we want to port to an architecture which + * implements differently sized types. it looks like 64bit systems with + * gcc are OK. + */ + +union int_float { + int i; + float f; +}; + +union long_double { + long long l; + double d; +}; + +#define getsb(off) ((char)buf[off]) +#define getub(off) (buf[off]) +#define getsw(off) ((short)(((unsigned)getub(off) << 8) | (unsigned)getub(off+1))) +#define getuw(off) ((unsigned short)(((unsigned)getub(off) << 8) | (unsigned)getub(off+1))) +#define getsl(off) ((int)(((unsigned)getuw(off) << 16) | getuw(off+2))) +#define getul(off) ((unsigned int)(((unsigned)getuw(off) << 16) | getuw(off+2))) +#define getsL(off) ((long long)(((unsigned long long)getul(off) << 32) | getul(off+4))) +#define getuL(off) ((unsigned long long)(((unsigned long long)getul(off) << 32) | getul(off+4))) +#define getf(off) (i_f.i = getsl(off), i_f.f) +#define getd(off) (l_d.l = getsL(off), l_d.d) |