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Re: Adjust empty class parameter passing ABI (PR c++/60336)
- From: Richard Biener <rguenther at suse dot de>
- To: Marek Polacek <polacek at redhat dot com>
- Cc: GCC Patches <gcc-patches at gcc dot gnu dot org>, Jason Merrill <jason at redhat dot com>, Joseph Myers <joseph at codesourcery dot com>, "H.J. Lu" <hjl dot tools at gmail dot com>
- Date: Fri, 27 Oct 2017 12:31:46 +0200 (CEST)
- Subject: Re: Adjust empty class parameter passing ABI (PR c++/60336)
- Authentication-results: sourceware.org; auth=none
- References: <20171027100056.GE12792@redhat.com>
On Fri, 27 Oct 2017, Marek Polacek wrote:
> This is my attempt at the empty class ABI change. To recap quickly, the C++
> compiler has used a different calling convention for passing empty classes,
> because C++ says they have size 1, while the GCC C extension gives them size 0.
> But this difference doesn't mean that they need to be passed differently; in
> either case there's no actual data involved.
>
> I've made use of all the previous patches:
> <https://gcc.gnu.org/ml/gcc-patches/2015-11/msg02064.html>
> <https://gcc.gnu.org/ml/gcc-patches/2016-03/msg00183.html>
> <https://gcc.gnu.org/ml/gcc-patches/2016-04/msg00559.html>
> but this approach uses two target hooks which check whether a type is an empty
> type according to the x86_64 psABI, and the second implements the warning for it.
> It also uses a lang hook to determine whether to print a -Wabi warning. The
> new passing can be turned back into the old passing using -fabi-version=11. So
> I had to use the new langhook, otherwise I wouldn't be able make it dependent
> on the C++ ABI verison.
>
> Some earlier comments from Jason:
> > I'm still uneasy about how much this requires generic code to think
> > about empty types specifically. I'd prefer to encapsulate this as
> > much as possible. Rather than places saying (empty ? 0 :
> > int_size_in_bytes), I figured that would all be hidden in the target
> > code, along with the warning. Places where you currently emit a
> > warning from generic code ought to come from a target hook, either an
> > existing one or a new one called something like
> > warn_parameter_passing_abi.
>
> I hope I've improved this now. I've introduced two new wrappers,
> maybe_empty_type_size, and int_maybe_empty_type_size. I've moved the
> warning to its own target hook with a new field in CUMULATIVE_ARGS; that
> seems to work well.
>
> > Note that nothing in gcc/ currently refers to warn_abi or warn_psabi,
> > which are both c-common flags; some targets refer to warn_psabi.
>
> True.
>
> > > It also uses a lang hook to determine
> > > whether to print a -Wabi warning. The new passing can be turned back into
> > > the old passing using -fabi-version=11. So I had to use a new langhook,
> > > otherwise I couldn't make it dependent on the C++ ABI verison.
> >
> > Hmm, that's unfortunate.
>
> It is, but the possibility of using -fabi-version=11 to revert to the old
> behavior seems useful.
>
> > > The users will get the new empty records passing even with -m32.
> >
> > I thought we only wanted to make the change for -m64; -m32 is a legacy
> > ABI at this point, it doesn't seem advisable to change it.
>
> Sure thing, done (using the TARGET_64BIT check in ix86_is_empty_record_p).
>
> > > One thing I wasn't sure about is what to do with a struct that contains
> > > a zero-length array. We should consider it an empty type, but my
> > > is_empty_record_p won't do that, the reason is that there doesn't seem
> > > to be any change regarding passing: older GCCs wouldn't pass such a struct
> > > via stack. So there's no warning for that, either.
> >
> > Not warning for that makes sense. Doing that by making
> > is_empty_record_p give the wrong answer seems unwise.
>
> is_empty_record_p should now give the correct answer. As I said yesterday,
> I think we shouldn't consider struct S { struct { } a; int b[0]; } as empty,
> because [0] is a GNU extension and struct S { struct { } a; int b[]; } is
> considered non-empty. Also, for the record, the struct with the flexible array
> member [0] broke struct-layout when considered empty. Thus the uglyfying of
> is_empty_record_p. empty23.C and empty24.C test that.
>
> > Also, you need to handled unnamed bit-fields, as they aren't data members.
>
> Here's another hiccup: e.g. struct S { unsigned : 15; }; are considered empty,
> but they were considered empty even before my change (so we probably shouldn't
> warn), with "unsigned : 0;" it's different and there seems to be a change in
> how we pass that. So I kept the warning. Not sure how important this is.
>
> Any other concerns?
I fear it doesn't work at all with LTO (you'll always get the old ABI
if I read the patch correctly). This is because the function
computing the size looks at flag_abi_version which isn't saved
per function / TU.
Similarly you'll never get the ABI warning with LTO (less of a big
deal of course) because the langhook doesn't reflect things correctly
either.
So... can we instead compute whether a type is "empty" according
to the ABI early and store the result in the type (thinking of
doing this in layout_type?). Similarly set a flag whether to
warn. Why do you warn from backends / code emission and not
from the FEs? Is that to avoid warnings for calls that got inlined?
Maybe the FE could set a flag on the call itself (ok, somewhat
awkward to funnel through gimple).
Richard.
> Bootstrapped/regtested on x86_64-linux, ppc64-linux, and aarch64-linux.
>
> 2017-10-27 Marek Polacek <polacek@redhat.com>
> H.J. Lu <hongjiu.lu@intel.com>
> Jason Merrill <jason@redhat.com>
>
> PR c++/60336
> PR middle-end/67239
> PR target/68355
> * calls.c (initialize_argument_information): Call
> warn_parameter_passing_abi target hook.
> (store_one_arg): Use 0 for empty record size. Don't push 0 size
> argument onto stack.
> (must_pass_in_stack_var_size_or_pad): Return false for empty types.
> * common.opt: Update -fabi-version description.
> * config/i386/i386.c (init_cumulative_args): Set cum->warn_empty.
> (ix86_function_arg_advance): Skip empty records.
> (ix86_return_in_memory): Return false for empty types.
> (ix86_gimplify_va_arg): Call int_maybe_empty_type_size instead of
> int_size_in_bytes.
> (ix86_is_empty_record_p): New function.
> (ix86_warn_parameter_passing_abi): New function.
> (TARGET_EMPTY_RECORD_P): Redefine.
> (TARGET_WARN_PARAMETER_PASSING_ABI): Redefine.
> * config/i386/i386.h (CUMULATIVE_ARGS): Add warn_empty.
> * doc/tm.texi: Regenerated.
> * doc/tm.texi.in (TARGET_EMPTY_RECORD_P,
> TARGET_WARN_PARAMETER_PASSING_ABI): Add.
> * explow.c (hard_function_value): Call int_maybe_empty_type_size
> instead of int_size_in_bytes.
> * expr.c (copy_blkmode_to_reg): Likewise.
> * function.c (assign_parm_find_entry_rtl): Call
> warn_parameter_passing_abi target hook.
> (locate_and_pad_parm): Call maybe_empty_type_size instead
> size_in_bytes.
> * langhooks-def.h (LANG_HOOKS_WARN_EMPTY_CLASS_ABI): Define.
> * langhooks.h (struct lang_hooks): Add warn_empty_class_abi.
> * target.def (empty_record_p, warn_parameter_passing_abi): New target
> hook.
> * targhooks.c (hook_void_CUMULATIVE_ARGS_tree): New hook.
> (std_gimplify_va_arg_expr): Skip empty records. Call
> maybe_empty_type_size instead size_in_bytes.
> * targhooks.h (hook_void_CUMULATIVE_ARGS_tree): Declare.
> * tree.c (array_type_nelts_top): New function.
> (is_empty_type): New function.
> (is_empty_record_p): New function.
> (int_maybe_empty_type_size): New function.
> (maybe_empty_type_size): New function.
> * tree.h (array_type_nelts_top, is_empty_record_p,
> int_maybe_empty_type_size, maybe_empty_type_size): Declare.
>
> * cp-lang.c: Include "flags.h".
> (LANG_HOOKS_WARN_EMPTY_CLASS_ABI): Redefine.
> (cxx_warn_empty_class_abi): New function.
> * cp-tree.h (array_type_nelts_top): Remove declaration.
> * tree.c (array_type_nelts_top): Move to tree.c.
>
> * testsuite/g++.dg/abi/empty12.C: New test.
> * testsuite/g++.dg/abi/empty12.h: New test.
> * testsuite/g++.dg/abi/empty12a.c: New test.
> * testsuite/g++.dg/abi/empty13.C: New test.
> * testsuite/g++.dg/abi/empty13.h: New test.
> * testsuite/g++.dg/abi/empty13a.c: New test.
> * testsuite/g++.dg/abi/empty14.C: New test.
> * testsuite/g++.dg/abi/empty14.h: New test.
> * testsuite/g++.dg/abi/empty14a.c: New test.
> * testsuite/g++.dg/abi/empty15.C: New test.
> * testsuite/g++.dg/abi/empty15.h: New test.
> * testsuite/g++.dg/abi/empty15a.c: New test.
> * testsuite/g++.dg/abi/empty16.C: New test.
> * testsuite/g++.dg/abi/empty16.h: New test.
> * testsuite/g++.dg/abi/empty16a.c: New test.
> * testsuite/g++.dg/abi/empty17.C: New test.
> * testsuite/g++.dg/abi/empty17.h: New test.
> * testsuite/g++.dg/abi/empty17a.c: New test.
> * testsuite/g++.dg/abi/empty18.C: New test.
> * testsuite/g++.dg/abi/empty18.h: New test.
> * testsuite/g++.dg/abi/empty18a.c: New test.
> * testsuite/g++.dg/abi/empty19.C: New test.
> * testsuite/g++.dg/abi/empty19.h: New test.
> * testsuite/g++.dg/abi/empty19a.c: New test.
> * testsuite/g++.dg/abi/empty20.C: New test.
> * testsuite/g++.dg/abi/empty21.C: New test.
> * testsuite/g++.dg/abi/empty22.C: New test.
> * testsuite/g++.dg/abi/empty22.h: New test.
> * testsuite/g++.dg/abi/empty22a.c: New test.
> * testsuite/g++.dg/abi/empty23.C: New test.
> * testsuite/g++.dg/abi/empty24.C: New test.
> * testsuite/g++.dg/abi/pr60336-1.C: New test.
> * testsuite/g++.dg/abi/pr60336-10.C: New test.
> * testsuite/g++.dg/abi/pr60336-11.C: New test.
> * testsuite/g++.dg/abi/pr60336-12.C: New test.
> * testsuite/g++.dg/abi/pr60336-2.C: New test.
> * testsuite/g++.dg/abi/pr60336-3.C: New test.
> * testsuite/g++.dg/abi/pr60336-4.C: New test.
> * testsuite/g++.dg/abi/pr60336-5.C: New test.
> * testsuite/g++.dg/abi/pr60336-6.C: New test.
> * testsuite/g++.dg/abi/pr60336-7.C: New test.
> * testsuite/g++.dg/abi/pr60336-8.C: New test.
> * testsuite/g++.dg/abi/pr60336-9.C: New test.
> * testsuite/g++.dg/abi/pr68355.C: New test.
>
> diff --git gcc/calls.c gcc/calls.c
> index 3730f43c7a9..29f547942d8 100644
> --- gcc/calls.c
> +++ gcc/calls.c
> @@ -1850,6 +1850,8 @@ initialize_argument_information (int num_actuals ATTRIBUTE_UNUSED,
> args[i].unsignedp = unsignedp;
> args[i].mode = mode;
>
> + targetm.calls.warn_parameter_passing_abi (args_so_far, type);
> +
> args[i].reg = targetm.calls.function_arg (args_so_far, mode, type,
> argpos < n_named_args);
>
> @@ -5358,7 +5360,11 @@ store_one_arg (struct arg_data *arg, rtx argblock, int flags,
> Note that in C the default argument promotions
> will prevent such mismatches. */
>
> - size = GET_MODE_SIZE (arg->mode);
> + if (targetm.calls.empty_record_p (TREE_TYPE (pval)))
> + size = 0;
> + else
> + size = GET_MODE_SIZE (arg->mode);
> +
> /* Compute how much space the push instruction will push.
> On many machines, pushing a byte will advance the stack
> pointer by a halfword. */
> @@ -5390,10 +5396,12 @@ store_one_arg (struct arg_data *arg, rtx argblock, int flags,
>
> /* This isn't already where we want it on the stack, so put it there.
> This can either be done with push or copy insns. */
> - if (!emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), NULL_RTX,
> - parm_align, partial, reg, used - size, argblock,
> - ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
> - ARGS_SIZE_RTX (arg->locate.alignment_pad), true))
> + if (used
> + && !emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval),
> + NULL_RTX, parm_align, partial, reg, used - size,
> + argblock, ARGS_SIZE_RTX (arg->locate.offset),
> + reg_parm_stack_space,
> + ARGS_SIZE_RTX (arg->locate.alignment_pad), true))
> sibcall_failure = 1;
>
> /* Unless this is a partially-in-register argument, the argument is now
> @@ -5426,9 +5434,9 @@ store_one_arg (struct arg_data *arg, rtx argblock, int flags,
> /* PUSH_ROUNDING has no effect on us, because emit_push_insn
> for BLKmode is careful to avoid it. */
> excess = (arg->locate.size.constant
> - - int_size_in_bytes (TREE_TYPE (pval))
> + - int_maybe_empty_type_size (TREE_TYPE (pval))
> + partial);
> - size_rtx = expand_expr (size_in_bytes (TREE_TYPE (pval)),
> + size_rtx = expand_expr (maybe_empty_type_size (TREE_TYPE (pval)),
> NULL_RTX, TYPE_MODE (sizetype),
> EXPAND_NORMAL);
> }
> @@ -5504,10 +5512,12 @@ store_one_arg (struct arg_data *arg, rtx argblock, int flags,
> }
> }
>
> - emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
> - parm_align, partial, reg, excess, argblock,
> - ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
> - ARGS_SIZE_RTX (arg->locate.alignment_pad), false);
> + if (!CONST_INT_P (size_rtx) || INTVAL (size_rtx) != 0)
> + emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
> + parm_align, partial, reg, excess, argblock,
> + ARGS_SIZE_RTX (arg->locate.offset),
> + reg_parm_stack_space,
> + ARGS_SIZE_RTX (arg->locate.alignment_pad), false);
>
> /* Unless this is a partially-in-register argument, the argument is now
> in the stack.
> @@ -5585,6 +5595,9 @@ must_pass_in_stack_var_size_or_pad (machine_mode mode, const_tree type)
> if (TREE_ADDRESSABLE (type))
> return true;
>
> + if (targetm.calls.empty_record_p (type))
> + return false;
> +
> /* If the padding and mode of the type is such that a copy into
> a register would put it into the wrong part of the register. */
> if (mode == BLKmode
> diff --git gcc/common.opt gcc/common.opt
> index 836f05b95a2..41d97ae7475 100644
> --- gcc/common.opt
> +++ gcc/common.opt
> @@ -932,7 +932,7 @@ Driver Undocumented
> ; Default in G++ 7.
> ;
> ; 12: Corrects the calling convention for classes with only deleted copy/move
> -; constructors.
> +; constructors and changes passing/returning of empty records.
> ; Default in G++ 8.
> ;
> ; Additional positive integers will be assigned as new versions of
> diff --git gcc/config/i386/i386.c gcc/config/i386/i386.c
> index 1facf121987..c7058ac5638 100644
> --- gcc/config/i386/i386.c
> +++ gcc/config/i386/i386.c
> @@ -7186,6 +7186,26 @@ init_cumulative_args (CUMULATIVE_ARGS *cum, /* Argument info to initialize */
> cum->force_bnd_pass = 0;
> cum->decl = fndecl;
>
> + cum->warn_empty = !warn_abi || cum->stdarg;
> + if (!cum->warn_empty && fntype)
> + {
> + function_args_iterator iter;
> + tree argtype;
> + bool seen_empty_type = false;
> + FOREACH_FUNCTION_ARGS (fntype, argtype, iter)
> + {
> + if (VOID_TYPE_P (argtype))
> + break;
> + if (targetm.calls.empty_record_p (argtype))
> + seen_empty_type = true;
> + else if (seen_empty_type)
> + {
> + cum->warn_empty = true;
> + break;
> + }
> + }
> + }
> +
> if (!TARGET_64BIT)
> {
> /* If there are variable arguments, then we won't pass anything
> @@ -8327,6 +8347,10 @@ ix86_function_arg_advance (cumulative_args_t cum_v, machine_mode mode,
> if (!cum->caller && cfun->machine->func_type != TYPE_NORMAL)
> return;
>
> + /* Skip empty records because they won't be passed. */
> + if (type && targetm.calls.empty_record_p (type))
> + return;
> +
> if (mode == BLKmode)
> bytes = int_size_in_bytes (type);
> else
> @@ -9293,6 +9317,10 @@ ix86_return_in_memory (const_tree type, const_tree fntype ATTRIBUTE_UNUSED)
> if (POINTER_BOUNDS_TYPE_P (type))
> return false;
>
> + /* Empty records are never passed in memory. */
> + if (type && targetm.calls.empty_record_p (type))
> + return false;
> +
> if (TARGET_64BIT)
> {
> if (ix86_function_type_abi (fntype) == MS_ABI)
> @@ -9873,7 +9901,7 @@ ix86_gimplify_va_arg (tree valist, tree type, gimple_seq *pre_p,
> indirect_p = pass_by_reference (NULL, TYPE_MODE (type), type, false);
> if (indirect_p)
> type = build_pointer_type (type);
> - size = int_size_in_bytes (type);
> + size = int_maybe_empty_type_size (type);
> rsize = CEIL (size, UNITS_PER_WORD);
>
> nat_mode = type_natural_mode (type, NULL, false);
> @@ -28772,6 +28800,44 @@ ix86_constant_alignment (const_tree exp, HOST_WIDE_INT align)
> return align;
> }
>
> +/* Implement TARGET_EMPTY_RECORD_P. */
> +
> +static bool
> +ix86_is_empty_record_p (const_tree type)
> +{
> + if (!TARGET_64BIT)
> + return false;
> + return is_empty_record_p (type);
> +}
> +
> +/* Implement TARGET_WARN_PARAMETER_PASSING_ABI. */
> +
> +static void
> +ix86_warn_parameter_passing_abi (cumulative_args_t cum_v, tree type)
> +{
> + CUMULATIVE_ARGS *cum = get_cumulative_args (cum_v);
> +
> + if (!cum->warn_empty)
> + return;
> +
> + if (!targetm.calls.empty_record_p (type))
> + return;
> +
> + if (!lang_hooks.warn_empty_class_abi ())
> + return;
> +
> + /* If the actual size of the type is zero, then there is no change
> + in how objects of this size are passed. */
> + if (int_size_in_bytes (type) == 0)
> + return;
> +
> + warning (OPT_Wabi, "empty class %qT parameter passing ABI "
> + "changes in -fabi-version=12 (GCC 8)", type);
> +
> + /* Only warn once. */
> + cum->warn_empty = false;
> +}
> +
> /* Compute the alignment for a variable for Intel MCU psABI. TYPE is
> the data type, and ALIGN is the alignment that the object would
> ordinarily have. */
> @@ -50311,6 +50377,12 @@ ix86_run_selftests (void)
> #undef TARGET_CONSTANT_ALIGNMENT
> #define TARGET_CONSTANT_ALIGNMENT ix86_constant_alignment
>
> +#undef TARGET_EMPTY_RECORD_P
> +#define TARGET_EMPTY_RECORD_P ix86_is_empty_record_p
> +
> +#undef TARGET_WARN_PARAMETER_PASSING_ABI
> +#define TARGET_WARN_PARAMETER_PASSING_ABI ix86_warn_parameter_passing_abi
> +
> #if CHECKING_P
> #undef TARGET_RUN_TARGET_SELFTESTS
> #define TARGET_RUN_TARGET_SELFTESTS selftest::ix86_run_selftests
> diff --git gcc/config/i386/i386.h gcc/config/i386/i386.h
> index 837906b5169..7f5d245b568 100644
> --- gcc/config/i386/i386.h
> +++ gcc/config/i386/i386.h
> @@ -1633,6 +1633,8 @@ typedef struct ix86_args {
> int warn_avx; /* True when we want to warn about AVX ABI. */
> int warn_sse; /* True when we want to warn about SSE ABI. */
> int warn_mmx; /* True when we want to warn about MMX ABI. */
> + int warn_empty; /* True when we want to warn about empty classes
> + passing ABI change. */
> int sse_regno; /* next available sse register number */
> int mmx_words; /* # mmx words passed so far */
> int mmx_nregs; /* # mmx registers available for passing */
> diff --git gcc/cp/cp-lang.c gcc/cp/cp-lang.c
> index 805319a4185..78336730a94 100644
> --- gcc/cp/cp-lang.c
> +++ gcc/cp/cp-lang.c
> @@ -26,6 +26,7 @@ along with GCC; see the file COPYING3. If not see
> #include "langhooks.h"
> #include "langhooks-def.h"
> #include "cp-objcp-common.h"
> +#include "flags.h"
>
> enum c_language_kind c_language = clk_cxx;
> static void cp_init_ts (void);
> @@ -35,6 +36,7 @@ static tree cp_eh_personality (void);
> static tree get_template_innermost_arguments_folded (const_tree);
> static tree get_template_argument_pack_elems_folded (const_tree);
> static tree cxx_enum_underlying_base_type (const_tree);
> +static bool cxx_warn_empty_class_abi (void);
>
> /* Lang hooks common to C++ and ObjC++ are declared in cp/cp-objcp-common.h;
> consequently, there should be very few hooks below. */
> @@ -78,6 +80,8 @@ static tree cxx_enum_underlying_base_type (const_tree);
> #define LANG_HOOKS_EH_RUNTIME_TYPE build_eh_type_type
> #undef LANG_HOOKS_ENUM_UNDERLYING_BASE_TYPE
> #define LANG_HOOKS_ENUM_UNDERLYING_BASE_TYPE cxx_enum_underlying_base_type
> +#undef LANG_HOOKS_WARN_EMPTY_CLASS_ABI
> +#define LANG_HOOKS_WARN_EMPTY_CLASS_ABI cxx_warn_empty_class_abi
>
> #if CHECKING_P
> #undef LANG_HOOKS_RUN_LANG_SELFTESTS
> @@ -234,6 +238,15 @@ tree cxx_enum_underlying_base_type (const_tree type)
> return underlying_type;
> }
>
> +/* Return true if we should warn about the change in empty class parameter
> + passing ABI. */
> +
> +static bool
> +cxx_warn_empty_class_abi (void)
> +{
> + return warn_abi && abi_version_crosses (12);
> +}
> +
> #if CHECKING_P
>
> namespace selftest {
> diff --git gcc/cp/cp-tree.h gcc/cp/cp-tree.h
> index f2570b00386..45f5d82be03 100644
> --- gcc/cp/cp-tree.h
> +++ gcc/cp/cp-tree.h
> @@ -6916,7 +6916,6 @@ extern tree canonical_eh_spec (tree);
> extern tree build_exception_variant (tree, tree);
> extern tree bind_template_template_parm (tree, tree);
> extern tree array_type_nelts_total (tree);
> -extern tree array_type_nelts_top (tree);
> extern tree break_out_target_exprs (tree);
> extern tree build_ctor_subob_ref (tree, tree, tree);
> extern tree replace_placeholders (tree, tree, bool * = NULL);
> diff --git gcc/cp/tree.c gcc/cp/tree.c
> index 48d40945af3..8a878d70e34 100644
> --- gcc/cp/tree.c
> +++ gcc/cp/tree.c
> @@ -2834,19 +2834,6 @@ cxx_print_statistics (void)
> }
>
> /* Return, as an INTEGER_CST node, the number of elements for TYPE
> - (which is an ARRAY_TYPE). This counts only elements of the top
> - array. */
> -
> -tree
> -array_type_nelts_top (tree type)
> -{
> - return fold_build2_loc (input_location,
> - PLUS_EXPR, sizetype,
> - array_type_nelts (type),
> - size_one_node);
> -}
> -
> -/* Return, as an INTEGER_CST node, the number of elements for TYPE
> (which is an ARRAY_TYPE). This one is a recursive count of all
> ARRAY_TYPEs that are clumped together. */
>
> diff --git gcc/doc/tm.texi gcc/doc/tm.texi
> index c02f4d35116..9c4405a4cb5 100644
> --- gcc/doc/tm.texi
> +++ gcc/doc/tm.texi
> @@ -4548,6 +4548,16 @@ This target hook returns the mode to be used when accessing raw return registers
> This target hook returns the mode to be used when accessing raw argument registers in @code{__builtin_apply_args}. Define this macro if the value in @var{reg_raw_mode} is not correct.
> @end deftypefn
>
> +@deftypefn {Target Hook} bool TARGET_EMPTY_RECORD_P (const_tree @var{type})
> +This target hook returns true if the type is an empty record. The default
> +is to return @code{false}.
> +@end deftypefn
> +
> +@deftypefn {Target Hook} void TARGET_WARN_PARAMETER_PASSING_ABI (cumulative_args_t @var{ca}, tree @var{type})
> +This target hook warns about the change in empty class parameter passing
> +ABI.
> +@end deftypefn
> +
> @node Caller Saves
> @subsection Caller-Saves Register Allocation
>
> diff --git gcc/doc/tm.texi.in gcc/doc/tm.texi.in
> index 37308e1e551..8b6b64f542f 100644
> --- gcc/doc/tm.texi.in
> +++ gcc/doc/tm.texi.in
> @@ -3437,6 +3437,10 @@ nothing when you use @option{-freg-struct-return} mode.
>
> @hook TARGET_GET_RAW_ARG_MODE
>
> +@hook TARGET_EMPTY_RECORD_P
> +
> +@hook TARGET_WARN_PARAMETER_PASSING_ABI
> +
> @node Caller Saves
> @subsection Caller-Saves Register Allocation
>
> diff --git gcc/explow.c gcc/explow.c
> index 662865d2808..5c864fedd1b 100644
> --- gcc/explow.c
> +++ gcc/explow.c
> @@ -2166,7 +2166,7 @@ hard_function_value (const_tree valtype, const_tree func, const_tree fntype,
> if (REG_P (val)
> && GET_MODE (val) == BLKmode)
> {
> - unsigned HOST_WIDE_INT bytes = int_size_in_bytes (valtype);
> + unsigned HOST_WIDE_INT bytes = int_maybe_empty_type_size (valtype);
> opt_scalar_int_mode tmpmode;
>
> /* int_size_in_bytes can return -1. We don't need a check here
> diff --git gcc/expr.c gcc/expr.c
> index 496d492c9fa..337bd6de579 100644
> --- gcc/expr.c
> +++ gcc/expr.c
> @@ -2746,7 +2746,7 @@ copy_blkmode_to_reg (machine_mode mode, tree src)
>
> x = expand_normal (src);
>
> - bytes = int_size_in_bytes (TREE_TYPE (src));
> + bytes = int_maybe_empty_type_size (TREE_TYPE (src));
> if (bytes == 0)
> return NULL_RTX;
>
> diff --git gcc/function.c gcc/function.c
> index 339419ee1da..b7f97bf0ae5 100644
> --- gcc/function.c
> +++ gcc/function.c
> @@ -2528,6 +2528,9 @@ assign_parm_find_entry_rtl (struct assign_parm_data_all *all,
> return;
> }
>
> + targetm.calls.warn_parameter_passing_abi (all->args_so_far,
> + data->passed_type);
> +
> entry_parm = targetm.calls.function_incoming_arg (all->args_so_far,
> data->promoted_mode,
> data->passed_type,
> @@ -4140,8 +4143,9 @@ locate_and_pad_parm (machine_mode passed_mode, tree type, int in_regs,
>
> part_size_in_regs = (reg_parm_stack_space == 0 ? partial : 0);
>
> - sizetree
> - = type ? size_in_bytes (type) : size_int (GET_MODE_SIZE (passed_mode));
> + sizetree = (type
> + ? maybe_empty_type_size (type)
> + : size_int (GET_MODE_SIZE (passed_mode)));
> where_pad = targetm.calls.function_arg_padding (passed_mode, type);
> boundary = targetm.calls.function_arg_boundary (passed_mode, type);
> round_boundary = targetm.calls.function_arg_round_boundary (passed_mode,
> diff --git gcc/langhooks-def.h gcc/langhooks-def.h
> index 61b081bd7cc..4cb31a68d3d 100644
> --- gcc/langhooks-def.h
> +++ gcc/langhooks-def.h
> @@ -132,6 +132,7 @@ extern int lhd_type_dwarf_attribute (const_tree, int);
> #define LANG_HOOKS_CUSTOM_FUNCTION_DESCRIPTORS false
> #define LANG_HOOKS_RUN_LANG_SELFTESTS lhd_do_nothing
> #define LANG_HOOKS_GET_SUBSTRING_LOCATION lhd_get_substring_location
> +#define LANG_HOOKS_WARN_EMPTY_CLASS_ABI hook_bool_void_false
>
> /* Attribute hooks. */
> #define LANG_HOOKS_ATTRIBUTE_TABLE NULL
> @@ -344,7 +345,8 @@ extern void lhd_end_section (void);
> LANG_HOOKS_DEEP_UNSHARING, \
> LANG_HOOKS_CUSTOM_FUNCTION_DESCRIPTORS, \
> LANG_HOOKS_RUN_LANG_SELFTESTS, \
> - LANG_HOOKS_GET_SUBSTRING_LOCATION \
> + LANG_HOOKS_GET_SUBSTRING_LOCATION, \
> + LANG_HOOKS_WARN_EMPTY_CLASS_ABI \
> }
>
> #endif /* GCC_LANG_HOOKS_DEF_H */
> diff --git gcc/langhooks.h gcc/langhooks.h
> index d1288f1965d..ed79b2d8626 100644
> --- gcc/langhooks.h
> +++ gcc/langhooks.h
> @@ -538,6 +538,9 @@ struct lang_hooks
> const char *(*get_substring_location) (const substring_loc &,
> location_t *out_loc);
>
> + /* Return true when we should warn about the empty class ABI change. */
> + bool (*warn_empty_class_abi) (void);
> +
> /* Whenever you add entries here, make sure you adjust langhooks-def.h
> and langhooks.c accordingly. */
> };
> diff --git gcc/target.def gcc/target.def
> index 6a1cd31f2ac..9445a412689 100644
> --- gcc/target.def
> +++ gcc/target.def
> @@ -5043,6 +5043,22 @@ DEFHOOK
> machine_mode, (int regno),
> default_get_reg_raw_mode)
>
> +/* Return true if a type is an empty record. */
> +DEFHOOK
> +(empty_record_p,
> + "This target hook returns true if the type is an empty record. The default\n\
> +is to return @code{false}.",
> + bool, (const_tree type),
> + hook_bool_const_tree_false)
> +
> +/* Warn about the change in empty class parameter passing ABI. */
> +DEFHOOK
> +(warn_parameter_passing_abi,
> + "This target hook warns about the change in empty class parameter passing\n\
> +ABI.",
> + void, (cumulative_args_t ca, tree type),
> + hook_void_CUMULATIVE_ARGS_tree)
> +
> HOOK_VECTOR_END (calls)
>
> DEFHOOK
> diff --git gcc/targhooks.c gcc/targhooks.c
> index 92ecc90d4d4..f117382d565 100644
> --- gcc/targhooks.c
> +++ gcc/targhooks.c
> @@ -734,6 +734,12 @@ hook_int_CUMULATIVE_ARGS_mode_tree_bool_0 (
> }
>
> void
> +hook_void_CUMULATIVE_ARGS_tree (cumulative_args_t ca ATTRIBUTE_UNUSED,
> + tree ATTRIBUTE_UNUSED)
> +{
> +}
> +
> +void
> default_function_arg_advance (cumulative_args_t ca ATTRIBUTE_UNUSED,
> machine_mode mode ATTRIBUTE_UNUSED,
> const_tree type ATTRIBUTE_UNUSED,
> @@ -2084,6 +2090,7 @@ std_gimplify_va_arg_expr (tree valist, tree type, gimple_seq *pre_p,
> /* va_list pointer is aligned to PARM_BOUNDARY. If argument actually
> requires greater alignment, we must perform dynamic alignment. */
> if (boundary > align
> + && !targetm.calls.empty_record_p (type)
> && !integer_zerop (TYPE_SIZE (type)))
> {
> t = build2 (MODIFY_EXPR, TREE_TYPE (valist), valist_tmp,
> @@ -2110,7 +2117,7 @@ std_gimplify_va_arg_expr (tree valist, tree type, gimple_seq *pre_p,
> }
>
> /* Compute the rounded size of the type. */
> - type_size = size_in_bytes (type);
> + type_size = maybe_empty_type_size (type);
> rounded_size = round_up (type_size, align);
>
> /* Reduce rounded_size so it's sharable with the postqueue. */
> diff --git gcc/targhooks.h gcc/targhooks.h
> index f60bca257f7..722608f35cc 100644
> --- gcc/targhooks.h
> +++ gcc/targhooks.h
> @@ -134,6 +134,8 @@ extern bool hook_bool_CUMULATIVE_ARGS_mode_tree_bool_true
> (cumulative_args_t, machine_mode, const_tree, bool);
> extern int hook_int_CUMULATIVE_ARGS_mode_tree_bool_0
> (cumulative_args_t, machine_mode, tree, bool);
> +extern void hook_void_CUMULATIVE_ARGS_tree
> + (cumulative_args_t, tree);
> extern const char *hook_invalid_arg_for_unprototyped_fn
> (const_tree, const_tree, const_tree);
> extern void default_function_arg_advance
> diff --git gcc/testsuite/g++.dg/abi/empty12.C gcc/testsuite/g++.dg/abi/empty12.C
> index e69de29bb2d..20d85ff873e 100644
> --- gcc/testsuite/g++.dg/abi/empty12.C
> +++ gcc/testsuite/g++.dg/abi/empty12.C
> @@ -0,0 +1,17 @@
> +// PR c++/60336
> +// { dg-do run { target { { i?86-*-* x86_64-*-* } && { ! { ia32 } } } } }
> +// { dg-options "-Wabi=11 -x c" }
> +// { dg-additional-sources "empty12a.c" }
> +// { dg-prune-output "command line option" }
> +
> +#include "empty12.h"
> +extern "C" void fun(struct dummy, struct foo);
> +
> +int main()
> +{
> + struct dummy d;
> + struct foo f = { -1, -2, -3, -4, -5 };
> +
> + fun(d, f); // { dg-warning "empty" }
> + return 0;
> +}
> diff --git gcc/testsuite/g++.dg/abi/empty12.h gcc/testsuite/g++.dg/abi/empty12.h
> index e69de29bb2d..c61afcda0fb 100644
> --- gcc/testsuite/g++.dg/abi/empty12.h
> +++ gcc/testsuite/g++.dg/abi/empty12.h
> @@ -0,0 +1,9 @@
> +struct dummy { };
> +struct foo
> +{
> + int i1;
> + int i2;
> + int i3;
> + int i4;
> + int i5;
> +};
> diff --git gcc/testsuite/g++.dg/abi/empty12a.c gcc/testsuite/g++.dg/abi/empty12a.c
> index e69de29bb2d..34a25bad75d 100644
> --- gcc/testsuite/g++.dg/abi/empty12a.c
> +++ gcc/testsuite/g++.dg/abi/empty12a.c
> @@ -0,0 +1,6 @@
> +#include "empty12.h"
> +void fun(struct dummy d, struct foo f)
> +{
> + if (f.i1 != -1)
> + __builtin_abort();
> +}
> diff --git gcc/testsuite/g++.dg/abi/empty13.C gcc/testsuite/g++.dg/abi/empty13.C
> index e69de29bb2d..0cb9a373e35 100644
> --- gcc/testsuite/g++.dg/abi/empty13.C
> +++ gcc/testsuite/g++.dg/abi/empty13.C
> @@ -0,0 +1,17 @@
> +// PR c++/60336
> +// { dg-do run { target { { i?86-*-* x86_64-*-* } && { ! { ia32 } } } } }
> +// { dg-options "-x c -fabi-version=11" }
> +// { dg-additional-sources "empty13a.c" }
> +// { dg-prune-output "command line option" }
> +
> +#include "empty13.h"
> +extern "C" void fun(struct dummy, struct foo);
> +
> +int main()
> +{
> + struct dummy d;
> + struct foo f = { -1, -2, -3, -4, -5 };
> +
> + fun(d, f);
> + return 0;
> +}
> diff --git gcc/testsuite/g++.dg/abi/empty13.h gcc/testsuite/g++.dg/abi/empty13.h
> index e69de29bb2d..c61afcda0fb 100644
> --- gcc/testsuite/g++.dg/abi/empty13.h
> +++ gcc/testsuite/g++.dg/abi/empty13.h
> @@ -0,0 +1,9 @@
> +struct dummy { };
> +struct foo
> +{
> + int i1;
> + int i2;
> + int i3;
> + int i4;
> + int i5;
> +};
> diff --git gcc/testsuite/g++.dg/abi/empty13a.c gcc/testsuite/g++.dg/abi/empty13a.c
> index e69de29bb2d..b4303a63826 100644
> --- gcc/testsuite/g++.dg/abi/empty13a.c
> +++ gcc/testsuite/g++.dg/abi/empty13a.c
> @@ -0,0 +1,6 @@
> +#include "empty13.h"
> +void fun(struct dummy d, struct foo f)
> +{
> + if (f.i1 == -1)
> + __builtin_abort();
> +}
> diff --git gcc/testsuite/g++.dg/abi/empty14.C gcc/testsuite/g++.dg/abi/empty14.C
> index e69de29bb2d..2868d8ad3f3 100644
> --- gcc/testsuite/g++.dg/abi/empty14.C
> +++ gcc/testsuite/g++.dg/abi/empty14.C
> @@ -0,0 +1,17 @@
> +// PR c++/60336
> +// { dg-do run { target { { i?86-*-* x86_64-*-* } && { ! { ia32 } } } } }
> +// { dg-options "-Wabi=11 -x c" }
> +// { dg-additional-sources "empty14a.c" }
> +// { dg-prune-output "command line option" }
> +
> +#include "empty14.h"
> +extern "C" void fun(struct dummy, struct foo);
> +
> +int main()
> +{
> + struct dummy d;
> + struct foo f = { -1, -2, -3, -4, -5 };
> +
> + fun(d, f); // { dg-warning "empty" }
> + return 0;
> +}
> diff --git gcc/testsuite/g++.dg/abi/empty14.h gcc/testsuite/g++.dg/abi/empty14.h
> index e69de29bb2d..5842279cf37 100644
> --- gcc/testsuite/g++.dg/abi/empty14.h
> +++ gcc/testsuite/g++.dg/abi/empty14.h
> @@ -0,0 +1,10 @@
> +struct dummy0 { };
> +struct dummy { struct dummy0 d[140]; };
> +struct foo
> +{
> + int i1;
> + int i2;
> + int i3;
> + int i4;
> + int i5;
> +};
> diff --git gcc/testsuite/g++.dg/abi/empty14a.c gcc/testsuite/g++.dg/abi/empty14a.c
> index e69de29bb2d..8b3d7800c36 100644
> --- gcc/testsuite/g++.dg/abi/empty14a.c
> +++ gcc/testsuite/g++.dg/abi/empty14a.c
> @@ -0,0 +1,6 @@
> +#include "empty14.h"
> +void fun(struct dummy d, struct foo f)
> +{
> + if (f.i1 != -1)
> + __builtin_abort();
> +}
> diff --git gcc/testsuite/g++.dg/abi/empty15.C gcc/testsuite/g++.dg/abi/empty15.C
> index e69de29bb2d..12385f78c78 100644
> --- gcc/testsuite/g++.dg/abi/empty15.C
> +++ gcc/testsuite/g++.dg/abi/empty15.C
> @@ -0,0 +1,17 @@
> +// PR c++/60336
> +// { dg-do run { target { { i?86-*-* x86_64-*-* } && { ! { ia32 } } } } }
> +// { dg-options "-Wabi=11 -x c" }
> +// { dg-additional-sources "empty15a.c" }
> +// { dg-prune-output "command line option" }
> +
> +#include "empty15.h"
> +extern "C" void fun(struct dummy, struct foo);
> +
> +int main()
> +{
> + struct dummy d;
> + struct foo f = { -1, -2, -3, -4, -5 };
> +
> + fun(d, f); // { dg-warning "empty" }
> + return 0;
> +}
> diff --git gcc/testsuite/g++.dg/abi/empty15.h gcc/testsuite/g++.dg/abi/empty15.h
> index e69de29bb2d..1c6f26f5ae8 100644
> --- gcc/testsuite/g++.dg/abi/empty15.h
> +++ gcc/testsuite/g++.dg/abi/empty15.h
> @@ -0,0 +1,30 @@
> +struct A1 {};
> +struct A2 {};
> +struct B1 { struct A1 a; struct A2 b; };
> +struct B2 { struct A1 a; struct A2 b; };
> +struct C1 { struct B1 a; struct B2 b; };
> +struct C2 { struct B1 a; struct B2 b; };
> +struct D1 { struct C1 a; struct C2 b; };
> +struct D2 { struct C1 a; struct C2 b; };
> +struct E1 { struct D1 a; struct D2 b; };
> +struct E2 { struct D1 a; struct D2 b; };
> +struct F1 { struct E1 a; struct E2 b; };
> +struct F2 { struct E1 a; struct E2 b; };
> +struct G1 { struct F1 a; struct F2 b; };
> +struct G2 { struct F1 a; struct F2 b; };
> +struct H1 { struct G1 a; struct G2 b; };
> +struct H2 { struct G1 a; struct G2 b; };
> +struct I1 { struct H1 a; struct H2 b; };
> +struct I2 { struct H1 a; struct H2 b; };
> +struct J1 { struct I1 a; struct I2 b; };
> +struct J2 { struct I1 a; struct I2 b; };
> +struct dummy { struct J1 a; struct J2 b; };
> +
> +struct foo
> +{
> + int i1;
> + int i2;
> + int i3;
> + int i4;
> + int i5;
> +};
> diff --git gcc/testsuite/g++.dg/abi/empty15a.c gcc/testsuite/g++.dg/abi/empty15a.c
> index e69de29bb2d..325b2c5ba09 100644
> --- gcc/testsuite/g++.dg/abi/empty15a.c
> +++ gcc/testsuite/g++.dg/abi/empty15a.c
> @@ -0,0 +1,6 @@
> +#include "empty15.h"
> +void fun(struct dummy d, struct foo f)
> +{
> + if (f.i1 != -1)
> + __builtin_abort();
> +}
> diff --git gcc/testsuite/g++.dg/abi/empty16.C gcc/testsuite/g++.dg/abi/empty16.C
> index e69de29bb2d..1ca52f9011e 100644
> --- gcc/testsuite/g++.dg/abi/empty16.C
> +++ gcc/testsuite/g++.dg/abi/empty16.C
> @@ -0,0 +1,17 @@
> +// PR c++/60336
> +// { dg-do run { target { { i?86-*-* x86_64-*-* } && { ! { ia32 } } } } }
> +// { dg-options "-Wabi=11 -x c" }
> +// { dg-additional-sources "empty16a.c" }
> +// { dg-prune-output "command line option" }
> +
> +#include "empty16.h"
> +extern "C" void fun(struct dummy, struct foo);
> +
> +int main()
> +{
> + struct dummy d;
> + struct foo f = { -1, -2, -3, -4, -5 };
> +
> + fun(d, f); // { dg-warning "empty" }
> + return 0;
> +}
> diff --git gcc/testsuite/g++.dg/abi/empty16.h gcc/testsuite/g++.dg/abi/empty16.h
> index e69de29bb2d..7552ae06576 100644
> --- gcc/testsuite/g++.dg/abi/empty16.h
> +++ gcc/testsuite/g++.dg/abi/empty16.h
> @@ -0,0 +1,16 @@
> +#ifdef __cplusplus
> +struct A1 {};
> +struct A2 {};
> +struct dummy : A1, A2 {} ;
> +#else
> +struct dummy {};
> +#endif
> +
> +struct foo
> +{
> + int i1;
> + int i2;
> + int i3;
> + int i4;
> + int i5;
> +};
> diff --git gcc/testsuite/g++.dg/abi/empty16a.c gcc/testsuite/g++.dg/abi/empty16a.c
> index e69de29bb2d..6cb7fbccecc 100644
> --- gcc/testsuite/g++.dg/abi/empty16a.c
> +++ gcc/testsuite/g++.dg/abi/empty16a.c
> @@ -0,0 +1,6 @@
> +#include "empty16.h"
> +void fun(struct dummy d, struct foo f)
> +{
> + if (f.i1 != -1)
> + __builtin_abort();
> +}
> diff --git gcc/testsuite/g++.dg/abi/empty17.C gcc/testsuite/g++.dg/abi/empty17.C
> index e69de29bb2d..d386e5481af 100644
> --- gcc/testsuite/g++.dg/abi/empty17.C
> +++ gcc/testsuite/g++.dg/abi/empty17.C
> @@ -0,0 +1,17 @@
> +// PR c++/60336
> +// { dg-do run { target { { i?86-*-* x86_64-*-* } && { ! { ia32 } } } } }
> +// { dg-options "-Wabi=11 -x c" }
> +// { dg-additional-sources "empty17a.c" }
> +// { dg-prune-output "command line option" }
> +
> +#include "empty17.h"
> +extern "C" void fun(struct dummy, struct foo);
> +
> +int main()
> +{
> + struct dummy d;
> + struct foo f = { -1, -2, -3, -4, -5 };
> +
> + fun(d, f); // { dg-warning "empty" }
> + return 0;
> +}
> diff --git gcc/testsuite/g++.dg/abi/empty17.h gcc/testsuite/g++.dg/abi/empty17.h
> index e69de29bb2d..9cf72baca2e 100644
> --- gcc/testsuite/g++.dg/abi/empty17.h
> +++ gcc/testsuite/g++.dg/abi/empty17.h
> @@ -0,0 +1,27 @@
> +#ifdef __cplusplus
> +struct A1
> +{
> + void foo (void);
> + unsigned int : 15;
> +};
> +struct A2
> +{
> + void bar (void);
> + unsigned int : 15;
> +};
> +struct dummy : A1, A2
> +{
> + unsigned int : 15;
> +};
> +#else
> +struct dummy {};
> +#endif
> +
> +struct foo
> +{
> + int i1;
> + int i2;
> + int i3;
> + int i4;
> + int i5;
> +};
> diff --git gcc/testsuite/g++.dg/abi/empty17a.c gcc/testsuite/g++.dg/abi/empty17a.c
> index e69de29bb2d..24408fde09c 100644
> --- gcc/testsuite/g++.dg/abi/empty17a.c
> +++ gcc/testsuite/g++.dg/abi/empty17a.c
> @@ -0,0 +1,6 @@
> +#include "empty17.h"
> +void fun(struct dummy d, struct foo f)
> +{
> + if (f.i1 != -1)
> + __builtin_abort();
> +}
> diff --git gcc/testsuite/g++.dg/abi/empty18.C gcc/testsuite/g++.dg/abi/empty18.C
> index e69de29bb2d..be69c6a2115 100644
> --- gcc/testsuite/g++.dg/abi/empty18.C
> +++ gcc/testsuite/g++.dg/abi/empty18.C
> @@ -0,0 +1,17 @@
> +// PR c++/60336
> +// { dg-do run { target { { i?86-*-* x86_64-*-* } && { ! { ia32 } } } } }
> +// { dg-options "-Wabi=11 -x c" }
> +// { dg-additional-sources "empty18a.c" }
> +// { dg-prune-output "command line option" }
> +
> +#include "empty18.h"
> +extern "C" void fun(struct dummy, struct foo);
> +
> +int main()
> +{
> + struct dummy d;
> + struct foo f = { -1, -2, -3, -4, -5 };
> +
> + fun(d, f);
> + return 0;
> +}
> diff --git gcc/testsuite/g++.dg/abi/empty18.h gcc/testsuite/g++.dg/abi/empty18.h
> index e69de29bb2d..86e7ecdd211 100644
> --- gcc/testsuite/g++.dg/abi/empty18.h
> +++ gcc/testsuite/g++.dg/abi/empty18.h
> @@ -0,0 +1,9 @@
> +struct dummy { int d[0]; };
> +struct foo
> +{
> + int i1;
> + int i2;
> + int i3;
> + int i4;
> + int i5;
> +};
> diff --git gcc/testsuite/g++.dg/abi/empty18a.c gcc/testsuite/g++.dg/abi/empty18a.c
> index e69de29bb2d..902860bdc01 100644
> --- gcc/testsuite/g++.dg/abi/empty18a.c
> +++ gcc/testsuite/g++.dg/abi/empty18a.c
> @@ -0,0 +1,6 @@
> +#include "empty18.h"
> +void fun(struct dummy d, struct foo f)
> +{
> + if (f.i1 != -1)
> + __builtin_abort();
> +}
> diff --git gcc/testsuite/g++.dg/abi/empty19.C gcc/testsuite/g++.dg/abi/empty19.C
> index e69de29bb2d..84f5b75558b 100644
> --- gcc/testsuite/g++.dg/abi/empty19.C
> +++ gcc/testsuite/g++.dg/abi/empty19.C
> @@ -0,0 +1,17 @@
> +// PR c++/60336
> +// { dg-do run { target { { i?86-*-* x86_64-*-* } && { ! { ia32 } } } } }
> +// { dg-options "-Wabi=11 -x c" }
> +// { dg-additional-sources "empty19a.c" }
> +// { dg-prune-output "command line option" }
> +
> +#include "empty19.h"
> +extern "C" void fun(struct dummy, struct foo);
> +
> +int main()
> +{
> + struct dummy d;
> + struct foo f = { -1, -2, -3, -4, -5 };
> +
> + fun(d, f);
> + return 0;
> +}
> diff --git gcc/testsuite/g++.dg/abi/empty19.h gcc/testsuite/g++.dg/abi/empty19.h
> index e69de29bb2d..616b87bdd93 100644
> --- gcc/testsuite/g++.dg/abi/empty19.h
> +++ gcc/testsuite/g++.dg/abi/empty19.h
> @@ -0,0 +1,10 @@
> +struct dummy0 { };
> +struct dummy { struct dummy0 d[0]; };
> +struct foo
> +{
> + int i1;
> + int i2;
> + int i3;
> + int i4;
> + int i5;
> +};
> diff --git gcc/testsuite/g++.dg/abi/empty19a.c gcc/testsuite/g++.dg/abi/empty19a.c
> index e69de29bb2d..767b1eb7320 100644
> --- gcc/testsuite/g++.dg/abi/empty19a.c
> +++ gcc/testsuite/g++.dg/abi/empty19a.c
> @@ -0,0 +1,6 @@
> +#include "empty19.h"
> +void fun(struct dummy d, struct foo f)
> +{
> + if (f.i1 != -1)
> + __builtin_abort();
> +}
> diff --git gcc/testsuite/g++.dg/abi/empty20.C gcc/testsuite/g++.dg/abi/empty20.C
> index e69de29bb2d..5022033f669 100644
> --- gcc/testsuite/g++.dg/abi/empty20.C
> +++ gcc/testsuite/g++.dg/abi/empty20.C
> @@ -0,0 +1,19 @@
> +// PR c++/60336
> +// { dg-options "-Wabi=11 -O0" }
> +
> +struct A { };
> +
> +void f(A, A) { } // No warning, trailing parms all empty
> +void f(A, A, int) { } // { dg-warning "ABI" "" { target { { i?86-*-* x86_64-*-* } && { ! { ia32 } } } } }
> +__attribute__ ((always_inline))
> +inline void f(A a, int i) // No warning, always inlined
> +{
> + f(a,a,i); // { dg-warning "ABI" "" { target { { i?86-*-* x86_64-*-* } && { ! { ia32 } } } } }
> +}
> +int main()
> +{
> + A a;
> + f(a,a);
> + f(a,a,42); // { dg-warning "ABI" "" { target { { i?86-*-* x86_64-*-* } && { ! { ia32 } } } } }
> + f(a,42);
> +}
> diff --git gcc/testsuite/g++.dg/abi/empty21.C gcc/testsuite/g++.dg/abi/empty21.C
> index e69de29bb2d..3b2e3b836b1 100644
> --- gcc/testsuite/g++.dg/abi/empty21.C
> +++ gcc/testsuite/g++.dg/abi/empty21.C
> @@ -0,0 +1,23 @@
> +// PR c++/60336
> +// { dg-options "-Wabi=11" }
> +
> +#include <stdarg.h>
> +
> +struct A { };
> +
> +void f(int i, ...)
> +{
> + va_list ap;
> + va_start (ap, i);
> + if (i >= 1)
> + va_arg (ap, A);
> + if (i >= 2)
> + va_arg (ap, int);
> +}
> +
> +int main()
> +{
> + f(0);
> + f(1, A()); // { dg-warning "ABI" "" { target { { i?86-*-* x86_64-*-* } && { ! { ia32 } } } } }
> + f(2, A(), 42); // { dg-warning "ABI" "" { target { { i?86-*-* x86_64-*-* } && { ! { ia32 } } } } }
> +}
> diff --git gcc/testsuite/g++.dg/abi/empty22.C gcc/testsuite/g++.dg/abi/empty22.C
> index e69de29bb2d..f4f4a02bf31 100644
> --- gcc/testsuite/g++.dg/abi/empty22.C
> +++ gcc/testsuite/g++.dg/abi/empty22.C
> @@ -0,0 +1,17 @@
> +// PR c++/60336
> +// { dg-do run { target { { i?86-*-* x86_64-*-* } && { ! { ia32 } } } } }
> +// { dg-options "-Wabi=11 -x c" }
> +// { dg-additional-sources "empty22a.c" }
> +// { dg-prune-output "command line option" }
> +
> +#include "empty22.h"
> +extern "C" void fun(struct dummy, struct foo);
> +
> +int main()
> +{
> + struct dummy d;
> + struct foo f = { -1, -2, -3, -4, -5 };
> +
> + fun(d, f); // { dg-warning "empty" }
> + return 0;
> +}
> diff --git gcc/testsuite/g++.dg/abi/empty22.h gcc/testsuite/g++.dg/abi/empty22.h
> index e69de29bb2d..8d54dc74519 100644
> --- gcc/testsuite/g++.dg/abi/empty22.h
> +++ gcc/testsuite/g++.dg/abi/empty22.h
> @@ -0,0 +1,27 @@
> +#ifdef __cplusplus
> +struct A1
> +{
> + void foo (void);
> + unsigned int : 0;
> +};
> +struct A2
> +{
> + void bar (void);
> + unsigned int : 0;
> +};
> +struct dummy : A1, A2
> +{
> + unsigned int : 0;
> +};
> +#else
> +struct dummy {};
> +#endif
> +
> +struct foo
> +{
> + int i1;
> + int i2;
> + int i3;
> + int i4;
> + int i5;
> +};
> diff --git gcc/testsuite/g++.dg/abi/empty22a.c gcc/testsuite/g++.dg/abi/empty22a.c
> index e69de29bb2d..7606c524263 100644
> --- gcc/testsuite/g++.dg/abi/empty22a.c
> +++ gcc/testsuite/g++.dg/abi/empty22a.c
> @@ -0,0 +1,6 @@
> +#include "empty22.h"
> +void fun(struct dummy d, struct foo f)
> +{
> + if (f.i1 != -1)
> + __builtin_abort();
> +}
> diff --git gcc/testsuite/g++.dg/abi/empty23.C gcc/testsuite/g++.dg/abi/empty23.C
> index e69de29bb2d..b97d2804529 100644
> --- gcc/testsuite/g++.dg/abi/empty23.C
> +++ gcc/testsuite/g++.dg/abi/empty23.C
> @@ -0,0 +1,25 @@
> +// PR c++/60336
> +// { dg-do run }
> +// { dg-options "-Wabi=11" }
> +
> +struct S
> +{
> + struct { } a;
> + __extension__ int b[0];
> +};
> +
> +struct S s;
> +struct S a[5];
> +
> +void
> +foo (struct S, struct S *arg1, struct S)
> +{
> + if (arg1 != &a[1])
> + __builtin_abort ();
> +}
> +
> +int
> +main ()
> +{
> + foo (s, &a[1], a[2]);
> +}
> diff --git gcc/testsuite/g++.dg/abi/empty24.C gcc/testsuite/g++.dg/abi/empty24.C
> index e69de29bb2d..81deb36ff9f 100644
> --- gcc/testsuite/g++.dg/abi/empty24.C
> +++ gcc/testsuite/g++.dg/abi/empty24.C
> @@ -0,0 +1,25 @@
> +// PR c++/60336
> +// { dg-do run }
> +// { dg-options "-Wabi=11" }
> +
> +struct S
> +{
> + struct { } a;
> + __extension__ int b[];
> +};
> +
> +struct S s;
> +struct S a[5];
> +
> +void
> +foo (struct S, struct S *arg1, struct S)
> +{
> + if (arg1 != &a[1])
> + __builtin_abort ();
> +}
> +
> +int
> +main ()
> +{
> + foo (s, &a[1], a[2]);
> +}
> diff --git gcc/testsuite/g++.dg/abi/pr60336-1.C gcc/testsuite/g++.dg/abi/pr60336-1.C
> index e69de29bb2d..59447890cec 100644
> --- gcc/testsuite/g++.dg/abi/pr60336-1.C
> +++ gcc/testsuite/g++.dg/abi/pr60336-1.C
> @@ -0,0 +1,17 @@
> +// { dg-do compile }
> +// { dg-options "-O2 -std=c++11 -fno-pic" }
> +// { dg-require-effective-target fpic }
> +
> +struct dummy { };
> +struct true_type { struct dummy i; };
> +
> +extern true_type y;
> +extern void xxx (true_type c);
> +
> +void
> +yyy (void)
> +{
> + xxx (y);
> +}
> +
> +// { dg-final { scan-assembler "jmp\[\t \]+\[^\$\]*?_Z3xxx9true_type" { target { { i?86-*-* x86_64-*-* } && { ! { ia32 } } } } } }
> diff --git gcc/testsuite/g++.dg/abi/pr60336-10.C gcc/testsuite/g++.dg/abi/pr60336-10.C
> index e69de29bb2d..960cc2307d1 100644
> --- gcc/testsuite/g++.dg/abi/pr60336-10.C
> +++ gcc/testsuite/g++.dg/abi/pr60336-10.C
> @@ -0,0 +1,50 @@
> +// { dg-do run { target { { i?86-*-* x86_64-*-* } && { ! { ia32 } } } } }
> +// { dg-options "-O2" }
> +
> +#include <stdarg.h>
> +
> +struct dummy0 { };
> +struct dummy1 { };
> +struct dummy : dummy0, dummy1 { };
> +
> +void
> +test (struct dummy a, int m, ...)
> +{
> + va_list va_arglist;
> + int i;
> + int count = 0;
> +
> + if (m == 0)
> + count++;
> + va_start (va_arglist, m);
> + i = va_arg (va_arglist, int);
> + if (i == 1)
> + count++;
> + i = va_arg (va_arglist, int);
> + if (i == 2)
> + i = va_arg (va_arglist, int);
> + count++;
> + if (i == 3)
> + count++;
> + i = va_arg (va_arglist, int);
> + if (i == 4)
> + count++;
> + i = va_arg (va_arglist, int);
> + if (i == 5)
> + count++;
> + i = va_arg (va_arglist, int);
> + if (i == 6)
> + count++;
> + va_end (va_arglist);
> + if (count != 7)
> + __builtin_abort ();
> +}
> +
> +struct dummy a0;
> +
> +int
> +main ()
> +{
> + test (a0, 0, 1, 2, 3, 4, 5, 6);
> + return 0;
> +}
> diff --git gcc/testsuite/g++.dg/abi/pr60336-11.C gcc/testsuite/g++.dg/abi/pr60336-11.C
> index e69de29bb2d..14cd6d0ff3d 100644
> --- gcc/testsuite/g++.dg/abi/pr60336-11.C
> +++ gcc/testsuite/g++.dg/abi/pr60336-11.C
> @@ -0,0 +1,56 @@
> +// { dg-do run { target { { i?86-*-* x86_64-*-* } && { ! { ia32 } } } } }
> +// { dg-options "-O2" }
> +
> +#include <stdarg.h>
> +
> +struct dummy0
> +{
> + void bar (void);
> +};
> +struct dummy1
> +{
> + void foo (void);
> +};
> +struct dummy : dummy0, dummy1 { };
> +
> +void
> +test (struct dummy a, int m, ...)
> +{
> + va_list va_arglist;
> + int i;
> + int count = 0;
> +
> + if (m == 0)
> + count++;
> + va_start (va_arglist, m);
> + i = va_arg (va_arglist, int);
> + if (i == 1)
> + count++;
> + i = va_arg (va_arglist, int);
> + if (i == 2)
> + i = va_arg (va_arglist, int);
> + count++;
> + if (i == 3)
> + count++;
> + i = va_arg (va_arglist, int);
> + if (i == 4)
> + count++;
> + i = va_arg (va_arglist, int);
> + if (i == 5)
> + count++;
> + i = va_arg (va_arglist, int);
> + if (i == 6)
> + count++;
> + va_end (va_arglist);
> + if (count != 7)
> + __builtin_abort ();
> +}
> +
> +struct dummy a0;
> +
> +int
> +main ()
> +{
> + test (a0, 0, 1, 2, 3, 4, 5, 6);
> + return 0;
> +}
> diff --git gcc/testsuite/g++.dg/abi/pr60336-12.C gcc/testsuite/g++.dg/abi/pr60336-12.C
> index e69de29bb2d..09917547930 100644
> --- gcc/testsuite/g++.dg/abi/pr60336-12.C
> +++ gcc/testsuite/g++.dg/abi/pr60336-12.C
> @@ -0,0 +1,57 @@
> +// { dg-do run { target { { i?86-*-* x86_64-*-* } && { ! { ia32 } } } } }
> +// { dg-options "-O2" }
> +
> +#include <stdarg.h>
> +
> +struct dummy0
> +{
> +};
> +struct dummy1
> +{
> + unsigned : 15;
> +};
> +struct dummy : dummy0, dummy1
> +{
> +};
> +
> +void
> +test (struct dummy a, int m, ...)
> +{
> + va_list va_arglist;
> + int i;
> + int count = 0;
> +
> + if (m == 0)
> + count++;
> + va_start (va_arglist, m);
> + i = va_arg (va_arglist, int);
> + if (i == 1)
> + count++;
> + i = va_arg (va_arglist, int);
> + if (i == 2)
> + i = va_arg (va_arglist, int);
> + count++;
> + if (i == 3)
> + count++;
> + i = va_arg (va_arglist, int);
> + if (i == 4)
> + count++;
> + i = va_arg (va_arglist, int);
> + if (i == 5)
> + count++;
> + i = va_arg (va_arglist, int);
> + if (i == 6)
> + count++;
> + va_end (va_arglist);
> + if (count != 7)
> + __builtin_abort ();
> +}
> +
> +struct dummy a0;
> +
> +int
> +main ()
> +{
> + test (a0, 0, 1, 2, 3, 4, 5, 6);
> + return 0;
> +}
> diff --git gcc/testsuite/g++.dg/abi/pr60336-2.C gcc/testsuite/g++.dg/abi/pr60336-2.C
> index e69de29bb2d..1c6c3eb8f01 100644
> --- gcc/testsuite/g++.dg/abi/pr60336-2.C
> +++ gcc/testsuite/g++.dg/abi/pr60336-2.C
> @@ -0,0 +1,48 @@
> +// { dg-do run { target { { i?86-*-* x86_64-*-* } && { ! { ia32 } } } } }
> +// { dg-options "-O2 -Wabi=11" }
> +
> +#include <stdarg.h>
> +
> +struct dummy { };
> +
> +void
> +test (struct dummy a, int m, ...) // { dg-warning "empty" }
> +{
> + va_list va_arglist;
> + int i;
> + int count = 0;
> +
> + if (m == 0)
> + count++;
> + va_start (va_arglist, m);
> + i = va_arg (va_arglist, int);
> + if (i == 1)
> + count++;
> + i = va_arg (va_arglist, int);
> + if (i == 2)
> + i = va_arg (va_arglist, int);
> + count++;
> + if (i == 3)
> + count++;
> + i = va_arg (va_arglist, int);
> + if (i == 4)
> + count++;
> + i = va_arg (va_arglist, int);
> + if (i == 5)
> + count++;
> + i = va_arg (va_arglist, int);
> + if (i == 6)
> + count++;
> + va_end (va_arglist);
> + if (count != 7)
> + __builtin_abort ();
> +}
> +
> +struct dummy a0;
> +
> +int
> +main ()
> +{
> + test (a0, 0, 1, 2, 3, 4, 5, 6); // { dg-warning "empty" }
> + return 0;
> +}
> diff --git gcc/testsuite/g++.dg/abi/pr60336-3.C gcc/testsuite/g++.dg/abi/pr60336-3.C
> index e69de29bb2d..4157e553b6b 100644
> --- gcc/testsuite/g++.dg/abi/pr60336-3.C
> +++ gcc/testsuite/g++.dg/abi/pr60336-3.C
> @@ -0,0 +1,15 @@
> +// { dg-do compile }
> +// { dg-options "-O2 -Wabi=11" }
> +
> +struct dummy { struct { } __attribute__((aligned (4))) a[7]; };
> +
> +extern void test1 (struct dummy, ...);
> +extern void (*test2) (struct dummy, ...);
> +
> +void
> +foo ()
> +{
> + struct dummy a0;
> + test1 (a0, 42); // { dg-warning "ABI" "" { target { { i?86-*-* x86_64-*-* } && { ! { ia32 } } } } }
> + test2 (a0, 42); // { dg-warning "ABI" "" { target { { i?86-*-* x86_64-*-* } && { ! { ia32 } } } } }
> +}
> diff --git gcc/testsuite/g++.dg/abi/pr60336-4.C gcc/testsuite/g++.dg/abi/pr60336-4.C
> index e69de29bb2d..266f67a537d 100644
> --- gcc/testsuite/g++.dg/abi/pr60336-4.C
> +++ gcc/testsuite/g++.dg/abi/pr60336-4.C
> @@ -0,0 +1,48 @@
> +// { dg-do run { target { { i?86-*-* x86_64-*-* } && { ! { ia32 } } } } }
> +// { dg-options "-O2 -fabi-version=11" }
> +
> +#include <stdarg.h>
> +
> +struct dummy { };
> +
> +void
> +test (struct dummy a, int m, ...)
> +{
> + va_list va_arglist;
> + int i;
> + int count = 0;
> +
> + if (m == 0)
> + count++;
> + va_start (va_arglist, m);
> + i = va_arg (va_arglist, int);
> + if (i == 1)
> + count++;
> + i = va_arg (va_arglist, int);
> + if (i == 2)
> + i = va_arg (va_arglist, int);
> + count++;
> + if (i == 3)
> + count++;
> + i = va_arg (va_arglist, int);
> + if (i == 4)
> + count++;
> + i = va_arg (va_arglist, int);
> + if (i == 5)
> + count++;
> + i = va_arg (va_arglist, int);
> + if (i == 6)
> + count++;
> + va_end (va_arglist);
> + if (count == 7)
> + __builtin_abort ();
> +}
> +
> +struct dummy a0;
> +
> +int
> +main ()
> +{
> + test (a0, 0, 1, 2, 3, 4, 5, 6);
> + return 0;
> +}
> diff --git gcc/testsuite/g++.dg/abi/pr60336-5.C gcc/testsuite/g++.dg/abi/pr60336-5.C
> index e69de29bb2d..fe838750f55 100644
> --- gcc/testsuite/g++.dg/abi/pr60336-5.C
> +++ gcc/testsuite/g++.dg/abi/pr60336-5.C
> @@ -0,0 +1,17 @@
> +// { dg-do compile }
> +// { dg-options "-O2 -std=c++11 -fno-pic" }
> +// { dg-require-effective-target fpic }
> +
> +struct dummy { };
> +struct true_type { struct dummy i; struct dummy j; };
> +
> +extern true_type y;
> +extern void xxx (true_type c);
> +
> +void
> +yyy (void)
> +{
> + xxx (y);
> +}
> +
> +// { dg-final { scan-assembler "jmp\[\t \]+\[^\$\]*?_Z3xxx9true_type" { target { { i?86-*-* x86_64-*-* } && { ! { ia32 } } } } } }
> diff --git gcc/testsuite/g++.dg/abi/pr60336-6.C gcc/testsuite/g++.dg/abi/pr60336-6.C
> index e69de29bb2d..6e08c8f06fa 100644
> --- gcc/testsuite/g++.dg/abi/pr60336-6.C
> +++ gcc/testsuite/g++.dg/abi/pr60336-6.C
> @@ -0,0 +1,17 @@
> +// { dg-do compile }
> +// { dg-options "-O2 -std=c++11 -fno-pic" }
> +// { dg-require-effective-target fpic }
> +
> +struct dummy { };
> +struct true_type { struct dummy i1; struct dummy i2; };
> +
> +extern true_type y;
> +extern void xxx (true_type c);
> +
> +void
> +yyy (void)
> +{
> + xxx (y);
> +}
> +
> +// { dg-final { scan-assembler "jmp\[\t \]+\[^\$\]*?_Z3xxx9true_type" { target { { i?86-*-* x86_64-*-* } && { ! { ia32 } } } } } }
> diff --git gcc/testsuite/g++.dg/abi/pr60336-7.C gcc/testsuite/g++.dg/abi/pr60336-7.C
> index e69de29bb2d..3b8b8ba6f35 100644
> --- gcc/testsuite/g++.dg/abi/pr60336-7.C
> +++ gcc/testsuite/g++.dg/abi/pr60336-7.C
> @@ -0,0 +1,17 @@
> +// { dg-do compile }
> +// { dg-options "-O2 -std=c++11 -fno-pic" }
> +// { dg-require-effective-target fpic }
> +
> +struct dummy { };
> +struct true_type { struct dummy i[120]; };
> +
> +extern true_type y;
> +extern void xxx (true_type c);
> +
> +void
> +yyy (void)
> +{
> + xxx (y);
> +}
> +
> +// { dg-final { scan-assembler "jmp\[\t \]+\[^\$\]*?_Z3xxx9true_type" { target { { i?86-*-* x86_64-*-* } && { ! { ia32 } } } } } }
> diff --git gcc/testsuite/g++.dg/abi/pr60336-8.C gcc/testsuite/g++.dg/abi/pr60336-8.C
> index e69de29bb2d..a1ffb64ef02 100644
> --- gcc/testsuite/g++.dg/abi/pr60336-8.C
> +++ gcc/testsuite/g++.dg/abi/pr60336-8.C
> @@ -0,0 +1,15 @@
> +// { dg-do compile }
> +// { dg-options "-O2 -Wabi=11" }
> +
> +struct dummy { struct{} a[7][3]; };
> +
> +extern void test1 (struct dummy, ...);
> +extern void (*test2) (struct dummy, ...);
> +
> +void
> +foo ()
> +{
> + struct dummy a0;
> + test1 (a0, 42); // { dg-warning "ABI" "" { target { { i?86-*-* x86_64-*-* } && { ! { ia32 } } } } }
> + test2 (a0, 42); // { dg-warning "ABI" "" { target { { i?86-*-* x86_64-*-* } && { ! { ia32 } } } } }
> +}
> diff --git gcc/testsuite/g++.dg/abi/pr60336-9.C gcc/testsuite/g++.dg/abi/pr60336-9.C
> index e69de29bb2d..393f02b62f0 100644
> --- gcc/testsuite/g++.dg/abi/pr60336-9.C
> +++ gcc/testsuite/g++.dg/abi/pr60336-9.C
> @@ -0,0 +1,28 @@
> +// { dg-do compile }
> +// { dg-options "-O2 -std=c++11 -fno-pic" }
> +// { dg-require-effective-target fpic }
> +
> +struct A1 {}; struct A2 {};
> +struct B1 { A1 a; A2 b; }; struct B2 { A1 a; A2 b; };
> +struct C1 { B1 a; B2 b; }; struct C2 { B1 a; B2 b; };
> +struct D1 { C1 a; C2 b; }; struct D2 { C1 a; C2 b; };
> +struct E1 { D1 a; D2 b; }; struct E2 { D1 a; D2 b; };
> +struct F1 { E1 a; E2 b; }; struct F2 { E1 a; E2 b; };
> +struct G1 { F1 a; F2 b; }; struct G2 { F1 a; F2 b; };
> +struct H1 { G1 a; G2 b; }; struct H2 { G1 a; G2 b; };
> +struct I1 { H1 a; H2 b; }; struct I2 { H1 a; H2 b; };
> +struct J1 { I1 a; I2 b; }; struct J2 { I1 a; I2 b; };
> +struct dummy { J1 a; J2 b; };
> +
> +struct true_type { struct dummy i; };
> +
> +extern true_type y;
> +extern void xxx (true_type c);
> +
> +void
> +yyy (void)
> +{
> + xxx (y);
> +}
> +
> +// { dg-final { scan-assembler "jmp\[\t \]+\[^\$\]*?_Z3xxx9true_type" { target { { i?86-*-* x86_64-*-* } && { ! { ia32 } } } } } }
> diff --git gcc/testsuite/g++.dg/abi/pr68355.C gcc/testsuite/g++.dg/abi/pr68355.C
> index e69de29bb2d..1354fc497b5 100644
> --- gcc/testsuite/g++.dg/abi/pr68355.C
> +++ gcc/testsuite/g++.dg/abi/pr68355.C
> @@ -0,0 +1,24 @@
> +// { dg-do compile }
> +// { dg-options "-O2 -std=c++11 -fno-pic" }
> +// { dg-require-effective-target fpic }
> +
> +template<typename _Tp, _Tp __v>
> +struct integral_constant
> +{
> + static constexpr _Tp value = __v;
> + typedef _Tp value_type;
> + typedef integral_constant<_Tp, __v> type;
> + constexpr operator value_type() const { return value; }
> +};
> +
> +typedef integral_constant<bool, true> true_type;
> +extern void xxx (true_type c);
> +
> +void
> +yyy (void)
> +{
> + true_type y;
> + xxx (y);
> +}
> +
> +// { dg-final { scan-assembler "jmp\[\t \]+\[^\$\]*?_Z3xxx17integral_constantIbLb1EE" { target i?86-*-* x86_64-*-* } } }
> diff --git gcc/tree.c gcc/tree.c
> index fa6fcb1da71..a32c238de5d 100644
> --- gcc/tree.c
> +++ gcc/tree.c
> @@ -3135,6 +3135,20 @@ array_type_nelts (const_tree type)
> ? max
> : fold_build2 (MINUS_EXPR, TREE_TYPE (max), max, min));
> }
> +
> +/* Return, as an INTEGER_CST node, the number of elements for TYPE
> + (which is an ARRAY_TYPE). This counts only elements of the top
> + array. */
> +
> +tree
> +array_type_nelts_top (const_tree type)
> +{
> + return fold_build2_loc (input_location,
> + PLUS_EXPR, sizetype,
> + array_type_nelts (type),
> + size_one_node);
> +}
> +
>
> /* If arg is static -- a reference to an object in static storage -- then
> return the object. This is not the same as the C meaning of `static'.
> @@ -13811,6 +13825,89 @@ get_nonnull_args (const_tree fntype)
> return argmap;
> }
>
> +/* Returns true if TYPE is a type where it and all of its subobjects
> + (recursively) are of structure, union, or array type. */
> +
> +static bool
> +is_empty_type (tree type)
> +{
> + if (RECORD_OR_UNION_TYPE_P (type))
> + {
> + for (tree field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field))
> + {
> + if (TREE_CODE (field) == FIELD_DECL)
> + {
> + tree ftype = TREE_TYPE (field);
> + /* Don't consider struct S { struct { } a; int b[0]; };
> + an empty type. */
> + if (TREE_CODE (ftype) == ARRAY_TYPE
> + && integer_zerop (array_type_nelts_top (ftype)))
> + {
> + tree t = DECL_CHAIN (field);
> + bool found = false;
> + /* See if the zero-length array is followed by another
> + FIELD_DECL. */
> + while (t)
> + {
> + if (TREE_CODE (t) == FIELD_DECL)
> + {
> + found = true;
> + break;
> + }
> + t = DECL_CHAIN (t);
> + }
> + if (!found)
> + return false;
> + }
> + if ((DECL_NAME (field) || RECORD_OR_UNION_TYPE_P (ftype))
> + && !is_empty_type (ftype))
> + return false;
> + }
> + }
> + return true;
> + }
> + else if (TREE_CODE (type) == ARRAY_TYPE)
> + return (integer_zerop (array_type_nelts_top (type))
> + || is_empty_type (TREE_TYPE (type)));
> + return false;
> +}
> +
> +/* Implement TARGET_EMPTY_RECORD_P. Return true if TYPE is an empty type
> + that shouldn't be passed via stack. */
> +
> +bool
> +is_empty_record_p (const_tree type)
> +{
> + if (!abi_version_at_least (12))
> + return false;
> +
> + if (type == error_mark_node)
> + return false;
> +
> + if (TREE_ADDRESSABLE (type))
> + return false;
> +
> + return is_empty_type (TYPE_MAIN_VARIANT (type));
> +}
> +
> +/* Like int_size_in_bytes, but handle empty records specially. */
> +
> +HOST_WIDE_INT
> +int_maybe_empty_type_size (const_tree type)
> +{
> + return (targetm.calls.empty_record_p (type)
> + ? 0 : int_size_in_bytes (type));
> +}
> +
> +/* Like size_in_bytes, but handle empty records specially. */
> +
> +tree
> +maybe_empty_type_size (const_tree type)
> +{
> + return (targetm.calls.empty_record_p (type)
> + ? size_zero_node : size_in_bytes (type));
> +}
> +
> /* List of pointer types used to declare builtins before we have seen their
> real declaration.
>
> diff --git gcc/tree.h gcc/tree.h
> index 7214ae2275c..fb8af8bac7d 100644
> --- gcc/tree.h
> +++ gcc/tree.h
> @@ -4099,6 +4099,7 @@ extern tree build_method_type (tree, tree);
> extern tree build_offset_type (tree, tree);
> extern tree build_complex_type (tree, bool named = false);
> extern tree array_type_nelts (const_tree);
> +extern tree array_type_nelts_top (const_tree);
>
> extern tree value_member (tree, tree);
> extern tree purpose_member (const_tree, tree);
> @@ -5434,6 +5435,9 @@ extern void gt_pch_nx (tree &, gt_pointer_operator, void *);
>
> extern bool nonnull_arg_p (const_tree);
> extern bool is_redundant_typedef (const_tree);
> +extern bool is_empty_record_p (const_tree);
> +extern HOST_WIDE_INT int_maybe_empty_type_size (const_tree);
> +extern tree maybe_empty_type_size (const_tree);
>
> extern location_t
> set_source_range (tree expr, location_t start, location_t finish);
>
> Marek
>
>
--
Richard Biener <rguenther@suse.de>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nuernberg)