6 thoughts on “how to compile ruby with gprof”

1. on mingw by default you’ll get

   sh-3.1$ make
   gcc -shared -Wl,–enable-auto-image-base,–enable-auto-import -Wl,–out-implib=libmsvcrt-ruby191.dll.a msvcrt-ruby191.def dln.o encoding.o prelude.o array.o bignum.o class.o compar.o complex.o dir.o enum.o enumerator.o error.o eval.o load.o proc.o file.o gc.o hash.o inits.o io.o marshal.o math.o numeric.o object.o pack.o parse.o process.o random.o range.o rational.o re.o regcomp.o regenc.o regerror.o regexec.o regparse.o regsyntax.o ruby.o safe.o signal.o sprintf.o st.o strftime.o string.o struct.o time.o transcode.o util.o variable.o version.o compile.o debug.o iseq.o vm.o vm_dump.o thread.o cont.o ascii.o us_ascii.o unicode.o utf_8.o newline.o langinfo.o fileblocks.o crypt.o lgamma_r.o strlcpy.o strlcat.o win32.o dmyext.o msvcrt-ruby191.res.o -lshell32 -lws2_32 -o msvcrt-ruby191.dll
   Creating library file: libmsvcrt-ruby191.dll.a
   dln.o: In function `fprintf’:
   C:/installs/build_env/mingw/bin/../lib/gcc/mingw32/3.4.5/../../../../include/stdio.h:243: undefined reference to `mcount’
   dln.o: In function `sprintf’:
   C:/installs/build_env/mingw/bin/../lib/gcc/mingw32/3.4.5/../../../../include/stdio.h:263: undefined reference to `mcount’
   dln.o: In function `dln_load’:
   C:/dev/ruby/downloads/ruby_trunk/dln.c:1206: undefined reference to `mcount’
   dln.o: In function `dln_find_1′:
   C:/dev/ruby/downloads/ruby_trunk/dln.c:1521: undefined reference to `mcount’
   dln.o: In function `dln_find_file_r’:
   C:/dev/ruby/downloads/ruby_trunk/dln.c:1499: undefined reference to `mcount’
   dln.o:C:/dev/ruby/downloads/ruby_trunk/dln.c:1514: more undefined references to `mcount’ follow
   collect2: ld returned 1 exit status
   make: *** [msvcrt-ruby191.dll] Error 1

   which means “you need to link with -pg, too!” (LDFLAGS and all its siblings, within Makefile)
   ref:
   http://lists-archives.org/mingw-users/01285-profiling-trouble-_monstartup-undefined.html

2. may want/need to edit Makefile and adding -pg to makefile, enc.mk

3. gcc -shared -o .ext/i386-mingw32/enc/encdb.so enc/encdb.o -L. -L. -L. -Wl,–enable-auto-image-base,–enable-auto-import -lmsvcrt-ruby191 -lshell32 -lws2_32
   enc/encdb.o: In function `Init_encdb’:
   C:/dev/ruby/downloads/ruby_trunk/./enc/encdb.c:23: undefined reference to `mcount’
   collect2: ld returned 1 exit status
   make[1]: *** [.ext/i386-mingw32/enc/encdb.so] Error 1

   meant “add -pg next to -lws2_32 in enc.mk”

4. http://github.com/hogelog/ruby-1.9.1-p0/tree/ee0f53e2559af9b564176f000ec4cd35e01ec06a/sample/_gprof_out

5. http://www.igvita.com/2009/06/13/profiling-ruby-with-googles-perftools/

6. note: to see any outputs you’ll want to analyze like
   C:> gprof msvcrt-ruby191.dll gmon.out