Hi all, A couple months ago I created a patch for movable initializer lists, as proposed in N4166. (A few additional details appeared during implementation, which I can document if anyone asks.) Reference: http://open-std.org/JTC1/SC22/WG21/docs/papers/2014/n4166.pdf
As I was in the final stages of debugging and running the full testsuite, my
motherboard burned out. Now I’m trying to get back into it, but the "make
check" targets won’t do anything at all. This problem has happened before, and
sometimes resolves itself mysteriously. I can’t do a proper clean reinstall now
because Clang (I’m on OS X) won’t build GCC; it seems to be confused by C++
source files named with .c. So, everything is getting bootstrapped from a trunk
version of GCC that I had sitting around. That’s probably not the problem,
though; something must be wrong with DejaGnu or the makefiles.
I’m sure I’m close to the finish line, but constantly reinstalling,
clean-rebuilding, and trying to diagnose tool failures seems like a waste of
time and an undue strain on my laptop. I would greatly appreciate help from a
more experienced contributor, or even just access to a proper build process on
a fast CPU. Or even just any kind of support or compensation for my GCC efforts
in general. There are several more proposals I should prototype, and I’ll be
getting either a lot more involved in GCC or a lot less.
(Yes, I know that a “compile farm” exists. It appears to be obsolete; perhaps
someone could vouch for it?)
The patch is missing testcases. Any contributions, review, or feedback would be
appreciated. To summarize its contents:
- gcc/cp/call.c:
build_list_conv: Allow rvalue reference tag in std::initializer_list.
convert_like_real: Support sequence-owning std::initializer_list:
Detect rvalue reference tag indicating ownership.
Initialize by constructor instead of as aggregate.
Disable static storage optimization for an owning list.
Disable the cleanup of the array of an owning list.
Disable the destructor of an owning list of trivial sequence.
compare_ics: Conversion of a list to owning/non-owning
std::initializer_list is preferred for nontrivial/trivial move constructor,
respectively.
set_up_extended_ref_temp: Do not build a destructor for a TARGET_EXPR with
no cleanup.
extend_ref_init_temps: Process a constructor call for
std::initializer_list, not aggregate initialization.
- gcc/cp/init.c:
perform_member_init: Process a constructor call for std::initializer_list,
not aggregate initialization.
- gcc/cp/class.c:
finish_struct: Accept new format of std::initializer_list<T&&>.
- gcc/cp/decl.c:
cp_finish_decl: Reject owning initializer lists as nonstatic members.
- gcc/cp/typeck.c:
check_return_expr: Reject owning initializer lists as return values.
- gcc/cp/pt.c:
unify: Deduction of T in std::initializer_list<T&&> ignores the rvalue
reference specifier.
- gcc/cp/search.c:
accessible_p: std::initializer_list is exempt from access checking.
- gcc/cp/semantics.c:
trait_expr_value: Owning initializer list is trivially destructible if its
sequence is.
- libstdc++-v3/libsupc++/initializer_list
class initializer_list<T>:
Preserve internal modifiable access to sequence.
Disable move assignment operator. (CWG DR 2432)
class initializer_list<T&&>: New.
- gcc/testsuite/g++.dg/cpp0x/pr57101.C: Emulate new <initializer_list>.
- gcc/testsuite/g++.dg/cpp1z/initlist-owned.C: Check order of destruction
functionality.
Incomplete.
- libstdc++-v3/testsuite/20_util/is_assignable/value.cc
Reverse availability checks on std::initializer_list value assignability.
Add checks for owning initializer lists.
- libstdc++-v3/testsuite/util/testsuite_random.h
Remove std::initializer_list assignment operation, and UB due to reliance
on unspecified storage of temporary values.
- Thanks,
David
movil.patch
Description: Binary data
