Unfortunately it's not that easy, although I'd love to fix it if I can
figure out how.
OS X 10.3 does have dlfcn.h and dlopen() - for 10.3, they added the
dlcompat library that uses the OS X NSLink* stuff to support dlopen and
dlsym. configure seems to pick that up fine.
It seems like the code that's there already should work fine, so I'm
not sure where else to look.
I'm not a C++ guru, so if there's C++ linking difficulties or something
I'm not sure I'll be able to figure that out without help.
I used the following short code to test loading the .dylib, and dlopen
works fine, but dlsym is less pretty - on OS X, it automatically
prepends an underscore to the symbol, which means that if you are
looking for main(), you ask for "main" and it looks for
"_main", which
is how the symbols are named in Mach-O.
This could be the source of a problem - how does GetAddressOfSymbol in
DynamicLinker.cpp use dlsym?
Does it assume anything about the symbol names?
#include <dlfcn.h> // dlcompat
int main(int argc, const char **argv){
void *obj = dlopen(argv[1], RTLD_NOW | RTLD_GLOBAL);
void * sym = dlsym(obj,argv[2]);
printf("done: obj was %x sym was %x %s\n", obj, sym , dlerror());
return 0;
}
-mike
On Jun 19, 2004, at 2:07 PM, Chris Lattner wrote:
> On Sat, 19 Jun 2004, Michael McCracken wrote:
>
>> Hi, I can't get opt to list (in -help) passes that I load using
-load.
>> I see in the list archives that a similar problem has been brought up
>> before but I didn't see whether it was resolved. Also, this is on
Mac
>> OS X, and the previous question was about Linux.
>
> The problem is that this has not been implemented yet on Mac OSX. If
> you're familiar with the OS/X interfaces for loading .so files, it
> should
> be pretty easy. Take a look at lib/Support/DynamicLinker.cpp. I think
> that OS/X doesn't have windows.h :), and it also doesn't have
dlopen.
> If
> you can provide the necessary magic for your platform, it should just
> work.
>
> -Chris
>
>
>
>
>> This problem happens with the Hello pass, so I'll use that to
>> illustrate. I'm using LLVM 1.2.
>> The plugin loads with no complaints, so dlopen() is returning success,
>> and OS X's dlcompat probably isn't the problem.
>> However, it never gets registered. I've included a transcript
below.
>>
>> I also included some info about the compiler versions, etc. - It's
OS
>> X
>> 10.3.4.
>> Note that on OS X, 'libtool' isn't gnu libtool - that's
called
>> 'glibtool', if that matters.
>>
>> Does anyone have some hints on how to get this working? Thanks.
>>
>> transcript:
>>
>> % cd llvm/lib/Transforms/Hello/
>> % make
>> Compiling Hello.cpp
>> Linking hello dynamic debug library
>> ----------------------------------------------------------------------
>> Libraries have been installed in:
>> /Users/mike/Documents/hpcl/LLVM/llvm/lib/Debug
>>
>> If you ever happen to want to link against installed libraries
>> in a given directory, LIBDIR, you must either use libtool, and
>> specify the full pathname of the library, or use the `-LLIBDIR'
>> flag during linking and do at least one of the following:
>> - add LIBDIR to the `DYLD_LIBRARY_PATH' environment variable
>> during execution
>>
>> See any operating system documentation about shared libraries for
>> more information, such as the ld(1) and ld.so(8) manual pages.
>> ----------------------------------------------------------------------
>> ======= Finished building hello dynamic debug library ======>>
Linking hello.o
>>
>> % opt -load ../../Debug/libhello.dylib -hello
>> Unknown command line argument '-hello'. Try: 'opt
--help'
>>
>> % g++ -v
>> Reading specs from /usr/libexec/gcc/darwin/ppc/3.3/specs
>> Thread model: posix
>> gcc version 3.3 20030304 (Apple Computer, Inc. build 1495)
>>
>> % glibtool --version
>> ltmain.sh (GNU libtool) 1.5 (1.1220 2003/04/05 19:32:58)
>>
>> _______________________________________________
>> LLVM Developers mailing list
>> LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu
>> http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev
>>
>
> -Chris
>
> --
> http://llvm.cs.uiuc.edu/
> http://www.nondot.org/~sabre/Projects/
>
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu
> http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev
>
On Sat, 19 Jun 2004, Michael McCracken wrote:> I used the following short code to test loading the .dylib, and dlopen > works fine, but dlsym is less pretty - on OS X, it automatically > prepends an underscore to the symbol, which means that if you are > looking for main(), you ask for "main" and it looks for "_main", which > is how the symbols are named in Mach-O. > This could be the source of a problem - how does GetAddressOfSymbol in > DynamicLinker.cpp use dlsym?I believe that GetAddressOfSymbol is only used by the JIT. The -load mechanism just dlopens a shared object. Shared objects for plugins have static constructors (".init" section) that are supposed to autoregister the pass when the plugin is loaded. I don't know anything about how dynamic object loading works on OS/X (obviously), but it sounds like it's not running the static constructor.> Does it assume anything about the symbol names?I don't know what it will take to get the JIT working on OS/X: it might have to autoprepend an _. Since we don't (yet) have a PPC JIT, this isn't an issue though. -Chris> On Jun 19, 2004, at 2:07 PM, Chris Lattner wrote: > > > On Sat, 19 Jun 2004, Michael McCracken wrote: > > > >> Hi, I can't get opt to list (in -help) passes that I load using -load. > >> I see in the list archives that a similar problem has been brought up > >> before but I didn't see whether it was resolved. Also, this is on Mac > >> OS X, and the previous question was about Linux. > > > > The problem is that this has not been implemented yet on Mac OSX. If > > you're familiar with the OS/X interfaces for loading .so files, it > > should > > be pretty easy. Take a look at lib/Support/DynamicLinker.cpp. I think > > that OS/X doesn't have windows.h :), and it also doesn't have dlopen. > > If > > you can provide the necessary magic for your platform, it should just > > work. > > > > -Chris > > > > > > > > > >> This problem happens with the Hello pass, so I'll use that to > >> illustrate. I'm using LLVM 1.2. > >> The plugin loads with no complaints, so dlopen() is returning success, > >> and OS X's dlcompat probably isn't the problem. > >> However, it never gets registered. I've included a transcript below. > >> > >> I also included some info about the compiler versions, etc. - It's OS > >> X > >> 10.3.4. > >> Note that on OS X, 'libtool' isn't gnu libtool - that's called > >> 'glibtool', if that matters. > >> > >> Does anyone have some hints on how to get this working? Thanks. > >> > >> transcript: > >> > >> % cd llvm/lib/Transforms/Hello/ > >> % make > >> Compiling Hello.cpp > >> Linking hello dynamic debug library > >> ---------------------------------------------------------------------- > >> Libraries have been installed in: > >> /Users/mike/Documents/hpcl/LLVM/llvm/lib/Debug > >> > >> If you ever happen to want to link against installed libraries > >> in a given directory, LIBDIR, you must either use libtool, and > >> specify the full pathname of the library, or use the `-LLIBDIR' > >> flag during linking and do at least one of the following: > >> - add LIBDIR to the `DYLD_LIBRARY_PATH' environment variable > >> during execution > >> > >> See any operating system documentation about shared libraries for > >> more information, such as the ld(1) and ld.so(8) manual pages. > >> ---------------------------------------------------------------------- > >> ======= Finished building hello dynamic debug library ======> >> Linking hello.o > >> > >> % opt -load ../../Debug/libhello.dylib -hello > >> Unknown command line argument '-hello'. Try: 'opt --help' > >> > >> % g++ -v > >> Reading specs from /usr/libexec/gcc/darwin/ppc/3.3/specs > >> Thread model: posix > >> gcc version 3.3 20030304 (Apple Computer, Inc. build 1495) > >> > >> % glibtool --version > >> ltmain.sh (GNU libtool) 1.5 (1.1220 2003/04/05 19:32:58) > >> > >> _______________________________________________ > >> LLVM Developers mailing list > >> LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu > >> http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev > >> > > > > -Chris > > > > -- > > http://llvm.cs.uiuc.edu/ > > http://www.nondot.org/~sabre/Projects/ > > > > _______________________________________________ > > LLVM Developers mailing list > > LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu > > http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev > > > > _______________________________________________ > LLVM Developers mailing list > LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu > http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev >-Chris -- http://llvm.cs.uiuc.edu/ http://www.nondot.org/~sabre/Projects/
OK, seems like I've got some more looking to do. From what I can find, the only difference with OS X and dynamic libraries is that you can't depend on the order of calling static constructors, but not that you can't depend on them getting called. :) If I find that library handling in LLVM needs changes to work with OS X, I'll send a patch. Thanks, -mike On Jun 19, 2004, at 3:25 PM, Chris Lattner wrote:> On Sat, 19 Jun 2004, Michael McCracken wrote: >> I used the following short code to test loading the .dylib, and dlopen >> works fine, but dlsym is less pretty - on OS X, it automatically >> prepends an underscore to the symbol, which means that if you are >> looking for main(), you ask for "main" and it looks for "_main", which >> is how the symbols are named in Mach-O. >> This could be the source of a problem - how does GetAddressOfSymbol in >> DynamicLinker.cpp use dlsym? > > I believe that GetAddressOfSymbol is only used by the JIT. The -load > mechanism just dlopens a shared object. Shared objects for plugins > have > static constructors (".init" section) that are supposed to autoregister > the pass when the plugin is loaded. > > I don't know anything about how dynamic object loading works on OS/X > (obviously), but it sounds like it's not running the static > constructor. > >> Does it assume anything about the symbol names? > > I don't know what it will take to get the JIT working on OS/X: it might > have to autoprepend an _. Since we don't (yet) have a PPC JIT, this > isn't > an issue though. > > -Chris > > > >> On Jun 19, 2004, at 2:07 PM, Chris Lattner wrote: >> >>> On Sat, 19 Jun 2004, Michael McCracken wrote: >>> >>>> Hi, I can't get opt to list (in -help) passes that I load using >>>> -load. >>>> I see in the list archives that a similar problem has been brought >>>> up >>>> before but I didn't see whether it was resolved. Also, this is on >>>> Mac >>>> OS X, and the previous question was about Linux. >>> >>> The problem is that this has not been implemented yet on Mac OSX. If >>> you're familiar with the OS/X interfaces for loading .so files, it >>> should >>> be pretty easy. Take a look at lib/Support/DynamicLinker.cpp. I >>> think >>> that OS/X doesn't have windows.h :), and it also doesn't have dlopen. >>> If >>> you can provide the necessary magic for your platform, it should just >>> work. >>> >>> -Chris >>> >>> >>> >>> >>>> This problem happens with the Hello pass, so I'll use that to >>>> illustrate. I'm using LLVM 1.2. >>>> The plugin loads with no complaints, so dlopen() is returning >>>> success, >>>> and OS X's dlcompat probably isn't the problem. >>>> However, it never gets registered. I've included a transcript below. >>>> >>>> I also included some info about the compiler versions, etc. - It's >>>> OS >>>> X >>>> 10.3.4. >>>> Note that on OS X, 'libtool' isn't gnu libtool - that's called >>>> 'glibtool', if that matters. >>>> >>>> Does anyone have some hints on how to get this working? Thanks. >>>> >>>> transcript: >>>> >>>> % cd llvm/lib/Transforms/Hello/ >>>> % make >>>> Compiling Hello.cpp >>>> Linking hello dynamic debug library >>>> -------------------------------------------------------------------- >>>> -- >>>> Libraries have been installed in: >>>> /Users/mike/Documents/hpcl/LLVM/llvm/lib/Debug >>>> >>>> If you ever happen to want to link against installed libraries >>>> in a given directory, LIBDIR, you must either use libtool, and >>>> specify the full pathname of the library, or use the `-LLIBDIR' >>>> flag during linking and do at least one of the following: >>>> - add LIBDIR to the `DYLD_LIBRARY_PATH' environment variable >>>> during execution >>>> >>>> See any operating system documentation about shared libraries for >>>> more information, such as the ld(1) and ld.so(8) manual pages. >>>> -------------------------------------------------------------------- >>>> -- >>>> ======= Finished building hello dynamic debug library ======>>>> Linking hello.o >>>> >>>> % opt -load ../../Debug/libhello.dylib -hello >>>> Unknown command line argument '-hello'. Try: 'opt --help' >>>> >>>> % g++ -v >>>> Reading specs from /usr/libexec/gcc/darwin/ppc/3.3/specs >>>> Thread model: posix >>>> gcc version 3.3 20030304 (Apple Computer, Inc. build 1495) >>>> >>>> % glibtool --version >>>> ltmain.sh (GNU libtool) 1.5 (1.1220 2003/04/05 19:32:58) >>>> >>>> _______________________________________________ >>>> LLVM Developers mailing list >>>> LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu >>>> http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev >>>> >>> >>> -Chris >>> >>> -- >>> http://llvm.cs.uiuc.edu/ >>> http://www.nondot.org/~sabre/Projects/ >>> >>> _______________________________________________ >>> LLVM Developers mailing list >>> LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu >>> http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev >>> >> >> _______________________________________________ >> LLVM Developers mailing list >> LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu >> http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev >> > > -Chris > > -- > http://llvm.cs.uiuc.edu/ > http://www.nondot.org/~sabre/Projects/ > > _______________________________________________ > LLVM Developers mailing list > LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu > http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev >