On 12 Mar 2014, at 2:30, Robert Mustacchi <[email protected]> wrote: > On 03/10/2014 10:34 PM, Daniel O'Connor wrote: >> >> On 11 Mar 2014, at 15:34, Prashanth Kumar <[email protected]> wrote: >>> If the binary being traced has static symbols in its symbol table, DTrace >>> should >>> be able to trace the function. Can you describe the example where you found >>> this >>> difference in FreeBSD and OSX? >> >> Unfortunately the static symbols don't show up in the symbol table (as shown >> by nm). >> >> Is there a compile or link flag which will change that? > > Because it's a static function the compiler may inline it, which may be > why you don't actually see an entry in nm nor that it can be found by > DTrace. You'll want to look at the disassembled output of your program > to see if it was inlined. Different compilers can and will do different > things. There generally are flags you can pass to the compiler to tell > it not to inline it, but that's compiler specific.
I just realised that my test contradicted the statement I made earlier.. However I checked my test program (static.c) and it the functions definitely appear in the symbol table. [mdtest 21:13] ~ >nm static|egrep '(foo|bar)' 0000000000400600 T bar 0000000000400620 t foo I also added the noinline attribute for good measure. It seems that _nothing_ shows up for executables, only shared libraries, this is OK for me since my code resides in a library but it is a bit surprised nonetheless.. >> (I'm not sure what the various numbers mean) > > The pid provider can instrument any instruction in a function, those are > the instruction offsets. Ahh, thanks. -- Daniel O'Connor software and network engineer for Genesis Software - http://www.gsoft.com.au "The nice thing about standards is that there are so many of them to choose from." -- Andrew Tanenbaum GPG Fingerprint - 5596 B766 97C0 0E94 4347 295E E593 DC20 7B3F CE8C
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