William Hu wrote: > Hi David, > > > What were the missing symbols? With the OCaml 4.10 package, I hit > problems with this: > > > > echo 'print_endline "hello, world"' > hello.ml > > > > ocamlc -custom -runtime-variant _shared -o hello.exe hello.ml > > > > I think that may be an issue upstream (libasmrun_shared.so IIRC is > broken on all platforms - on Cygwin, you can just about to persuade it to > get to the same symbol errors because of the extra .dll.a file which gets > generated). > > It's a very long list of missing symbols (~400) so it's included as an > attachment in case the mailing list truncates extremely lengthy emails. > Also, just to note, the .dll.a file doesn't seem to be automatically > generated by upstream OCaml.
I think this down to neglect - the PIC/shared versions of the runtime were contributed for a specific purpose and aren't properly maintained/tested AFAICT. I'm not sure that libcamlrun_shared can ever have worked on Cygwin, at least certainly not since OCaml 3.11 (which is a loooong time ago). The patch builds cygcamlrun_shared.dll as a plugin DLL - so the symbols will have been stripped and moved into symtbl (hence the huge number of missing symbols when linking against it when it gets passed to a normal linker). What normally happens with flexlink is that either an executable or a "main program DLL" (compiled with flexlink -maindll) would receive that symtbl from a DLL it flexdll_dlopen's and the DLL receives static_symtbl from the executable. That then means that the DLL can relocate any symbols it expected from the main executable and any other flexdll_dlopen'd DLLs. However, that's all meant to happen at runtime - I don't think flexlink has ever supported compiling an executable _itself_ which must flexdll_dlopen DLLs _before_ its main function. I think it's quite feasible to add that to flexlink, but it's not a small piece of work - in the meantime I'd suggest instead deleting the BYTECODE_SHARED_LIBRARIES += and NATIVE_SHARED_LIBRARIES += lines in runtime/Makefile instead of patching them. > > What's the full configuration command and what gets inferred for the > build, host and target triplets? fma should work without emulation in > Cygwin32 and it should be detecting as failing on Cygwin64 but the > emulation should be enabled by default unless you explicitly passed -- > disable-imprecise-c99-float-ops. > > Configuration command: > ./configure --prefix=/usr --enable-ocamltest > > If it's relevant, I'm compiling on a 64-bit machine with Cygwin32 > installed to compile the 32-bit version. Inferred build/host/target: > configure:2779: Configuring OCaml version 4.14.0 > configure:3007: checking build system type > configure:3021: result: i686-pc-cygwin > configure:3041: checking host system type > configure:3054: result: i686-pc-cygwin > configure:3074: checking target system type > configure:3087: result: i686-pc-cygwin > > On Cygwin64, the test does fail and emulate by default: > > configure:14872: result: no > configure:14896: WARNING: fma does not work; emulation enabled > > However, on Cygwin32, I get > > configure:14872: result: no > configure:14894: error: fma does not work, enable emulation with --enable- > imprecise-c99-float-ops > > config.log conveniently includes the program that fails, so I copy-pasted > some very redundant code (attached) and ran it on the different > architectures: > > Cygwin64: > t264| ans: 0x0p+0 accept: 0x1.0989687cp-1044 0x1.09df287cp-1044 0x1.0ap- > 1044 > t264| pass?: 0 > t265| ans: 0x0p+0 accept: 0x1.0988p-1060 0x1.09ep-1060 0x1.0ap-1060 > t265| pass?: 0 > t266| ans: 0x1p-1074 accept: 0x1p-1073 > t266| pass?: 0 > > Cygwin32: > t264| ans: 0x1.0ap-1044 accept: 0x1.0989687cp-1044 0x1.09df287cp-1044 > 0x1.0ap-1044 > t264| pass?: 1 > t265| ans: 0x1.0ap-1060 accept: 0x1.0988p-1060 0x1.09ep-1060 0x1.0ap- > 1060 > t265| pass?: 1 > t266| ans: 0x1p-1073 accept: 0x1p-1073 > t266| pass?: 1 > > The numbers look like they agree but configure doesn't think so for some > reason. Would you be able to send the entire config.log file (off-list is fine!). I'm not seeing this at all in Cygwin32 here! All best, David
