Original bug ID: 4114
Reporter: weimer
Status: closed (set by @xavierleroy on 2006-09-20T17:41:03Z)
Resolution: fixed
Priority: normal
Severity: crash
Version: 3.09.2
Category: ~DO NOT USE (was: OCaml general)
Related to: #4036

Bug description

The i386/OS X native code gc chokes on large arrays that are handled fine on win32 or linux.

The example code below compiles fine with ocamlopt.opt under i386 OS X (3.09.2 compiled from the source tarball today). It also compiles fine on i386/win32 (for example, the mingw 3.09.0 binaries) and i386/linux (fedora core, whatever).

It runs correctly on i386/win32 and i386/linux but it crashes with "illegal instruction" on i386/osx. GDB:

Starting program: /Users/weimer/src/a.out
Reading symbols for shared libraries . done
*** You'll see this message, but no others.

Program received signal EXC_BAD_INSTRUCTION, Illegal instruction/operand.
0x0000da26 in caml_empty_minor_heap ()
(gdb) bt
#0 0x0000da26 in caml_empty_minor_heap ()
#1 0x0000dac0 in caml_minor_collection ()
#2 0x0000c302 in caml_garbage_collection ()
#3 0x000198fc in caml_call_gc ()
#4 0x0000b647 in main ()
(gdb) quit

The problem is not with my ocaml setup in general -- other programs work fine, and even the first printf in this program works fine.

Yes, it's a big array. This particular one was generated by a GLR parser generator.

To reproduce:

$ ocamlopt.opt small-example.ml
$ ./a.out

Sadly, this "small example" can't actually be made much smaller (the big arrays seem to be the problem) but I have removed all of the unnecessary code -- it's just a data structure definition sandwiched between two printfs. I have searched for similar bug reports but did not find anything; my apologies if this is a duplicate.

File attachments

• small-example.ml