Hi Guenter, On Wed, 19 Dec 2012 17:07:33 -0800, Guenter Roeck wrote: > Seen with latest i2c-tools from svn repository. With the subversion repository having gone on vacation, "latest" doesn't mean much :( > gcc 4.6: > > gcc-4.6 -Llib -li2c -o tools/i2cdetect tools/i2cdetect.o tools/i2cbusses.o > tools/i2cdetect.o: In function `main': > i2cdetect.c:(.text.startup+0x557): undefined reference to `i2c_smbus_write_quick' > i2cdetect.c:(.text.startup+0x5e9): undefined reference to `i2c_smbus_read_byte' > collect2: ld returned 1 exit status > make: *** [tools/i2cdetect] Error 1 > > gcc-4.4: > gcc-4.4 -Llib -li2c -o tools/i2cdetect tools/i2cdetect.o tools/i2cbusses.o > > [ no error ] > > Any idea ? I'm using gcc 4.6.2 (from openSUSE 12.1) and "the latest i2c-tools" (that would be from October 25th if I can trust the CHANGES timestamp) builds just fine for me. OTOH this is a linking problem, not building problem, so the version of "ld" may be more relevant. Are you using the same version of "ld" in both cases? The error messages suggest that gcc (and subsequently ld) doesn't find the symbols exported by libi2c. I can't figure out any reason why it would be so. Can you show us the output of "nm lib/libi2c.so.0.1.0"? This is what I get here: 0000000000201e30 a _DYNAMIC 0000000000201fe8 a _GLOBAL_OFFSET_TABLE_ w _Jv_RegisterClasses 0000000000201e10 d __CTOR_END__ 0000000000201e08 d __CTOR_LIST__ 0000000000201e20 d __DTOR_END__ 0000000000201e18 d __DTOR_LIST__ 0000000000000f10 r __FRAME_END__ 0000000000201e28 d __JCR_END__ 0000000000201e28 d __JCR_LIST__ 0000000000202028 a __bss_start w __cxa_finalize@@GLIBC_2.2.5 0000000000000c90 t __do_global_ctors_aux 0000000000000850 t __do_global_dtors_aux 0000000000202020 d __dso_handle U __errno_location@@GLIBC_2.2.5 w __gmon_start__ 0000000000202028 a _edata 0000000000202038 a _end 0000000000000cc8 t _fini 00000000000007c8 t _init 0000000000000cd8 t _real_fini 0000000000000830 t call_gmon_start 0000000000202028 b completed.5890 0000000000202030 b dtor_idx.5892 00000000000008d0 t frame_dummy 0000000000000900 T i2c_smbus_access 0000000000000c00 T i2c_smbus_block_process_call 0000000000000a40 T i2c_smbus_process_call 0000000000000a70 T i2c_smbus_read_block_data 0000000000000950 T i2c_smbus_read_byte 00000000000009a0 T i2c_smbus_read_byte_data 0000000000000b30 T i2c_smbus_read_i2c_block_data 00000000000009f0 T i2c_smbus_read_word_data 0000000000000ad0 T i2c_smbus_write_block_data 0000000000000980 T i2c_smbus_write_byte 00000000000009d0 T i2c_smbus_write_byte_data 0000000000000ba0 T i2c_smbus_write_i2c_block_data 0000000000000940 T i2c_smbus_write_quick 0000000000000a20 T i2c_smbus_write_word_data U ioctl@@GLIBC_2.2.5 This could also be a Makefile dependency issue... I can't remember what, if anything, guarantees that the library is built before the tools which use it. -- Jean Delvare -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html