[Bug #19575]
struct vtm is packed causing it to have a size that is not aligned on
32-bit systems. When allocating it on the stack, it will have unaligned
addresses which means that the fields won't be marked by the GC when
scanning the stack (since the GC only marks aligned addresses). This can
cause crashes when the fields are heap allocated objects like Bignums.
This commit moves the flags in struct time_object into struct vtm for
space efficiency and removes the need for packing.
This is an example of a crash:
ruby(rb_print_backtrace+0xd) [0x56848945] ../src/vm_dump.c:785
ruby(rb_vm_bugreport) ../src/vm_dump.c:1101
ruby(rb_assert_failure+0x7a) [0x56671857] ../src/error.c:878
ruby(vm_search_cc+0x0) [0x56666e47] ../src/vm_method.c:1366
ruby(rb_vm_search_method_slowpath) ../src/vm_insnhelper.c:2090
ruby(callable_method_entry+0x5) [0x568232d3] ../src/vm_method.c:1406
ruby(rb_callable_method_entry) ../src/vm_method.c:1413
ruby(gccct_method_search_slowpath) ../src/vm_eval.c:427
ruby(gccct_method_search+0x20f) [0x568237ef] ../src/vm_eval.c:476
ruby(opt_equality_by_mid_slowpath+0x2c) [0x5682388c] ../src/vm_insnhelper.c:2338
ruby(rb_equal+0x37) [0x566fe577] ../src/object.c:133
ruby(rb_big_eq+0x34) [0x56876ee4] ../src/bignum.c:5554
ruby(rb_int_equal+0x14) [0x566f3ed4] ../src/numeric.c:4640
ruby(rb_int_equal) ../src/numeric.c:4634
ruby(vm_call0_cfunc_with_frame+0x6d) [0x568303c2] ../src/vm_eval.c:148
ruby(vm_call0_cfunc) ../src/vm_eval.c:162
ruby(vm_call0_body) ../src/vm_eval.c:208
ruby(rb_funcallv_scope+0xd1) [0x56833971] ../src/vm_eval.c:85
ruby(RB_TEST+0x0) [0x567e8488] ../src/time.c:78
ruby(eq) ../src/time.c:78
ruby(small_vtm_sub) ../src/time.c:1523
ruby(timelocalw+0x23b) [0x567f3e9b] ../src/time.c:1593
ruby(time_s_alloc+0x0) [0x567f536b] ../src/time.c:3698
ruby(time_new_timew) ../src/time.c:2694
ruby(time_s_mktime) ../src/time.c:3698
Saves comitters' daily life by avoid #include-ing everything from
internal.h to make each file do so instead. This would significantly
speed up incremental builds.
We take the following inclusion order in this changeset:
1. "ruby/config.h", where _GNU_SOURCE is defined (must be the very
first thing among everything).
2. RUBY_EXTCONF_H if any.
3. Standard C headers, sorted alphabetically.
4. Other system headers, maybe guarded by #ifdef
5. Everything else, sorted alphabetically.
Exceptions are those win32-related headers, which tend not be self-
containing (headers have inclusion order dependencies).
Because hard to specify commits related to r67479 only.
So please commit again.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@67499 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
There's no point in having separate types depending on C dialect
when using bitfields, "unsigned int" bitfields are bitfields
anywhere.
Note: we also have test_memsize in test_time.rb in case
users of other platforms want to enable size assertions
if they don't trust their compiler.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@61870 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
To be precise C90 says "A bit-field may have type int, unsigned
int, or signed int". It is clear that char or enum are NG.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@61554 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
struct time_object shrinks from 88 to 46 bytes on my 64-bit system.
* configure.in: use -Wno-packed-bitfield-compat for GCC 4.4+
use __attribute__((packed)) if available
* timev.h: shrink and pack struct vtm
* time.c: pack struct time_object and adjust/introduce helpers
[ruby-core:60794]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@45155 b2dd03c8-39d4-4d8f-98ff-823fe69b080e