On Mon, Dec 5, 2016 at 1:29 PM, Lynn A. Boger <labo...@linux.vnet.ibm.com> wrote: > I think you mean https://github.com/golang/go/issues/18200.
Yes, thanks, I meant to write https://golang.org/issue/18200. Ian > On 12/05/2016 02:52 PM, Ian Lance Taylor wrote: >> >> On Sun, Sep 4, 2016 at 1:10 PM, Eric Botcazou <ebotca...@adacore.com> >> wrote: >>> >>> 2016-07-04 Eric Botcazou <ebotca...@adacore.com> >>> >>> PR ada/37139 >>> PR ada/67205 >>> * common.opt (-ftrampolines): New option. >>> * doc/invoke.texi (Code Gen Options): Document it. >>> * doc/tm.texi.in (Trampolines): >>> AddTARGET_CUSTOM_FUNCTION_DESCRIPTORS >>> * doc/tm.texi: Regenerate. >>> * builtins.def: Add init_descriptor and adjust_descriptor. >>> * builtins.c (expand_builtin_init_trampoline): Do not issue a >>> warning >>> on platforms with descriptors. >>> (expand_builtin_init_descriptor): New function. >>> (expand_builtin_adjust_descriptor): Likewise. >>> (expand_builtin) <BUILT_IN_INIT_DESCRIPTOR>: New case. >>> <BUILT_IN_ADJUST_DESCRIPTOR>: Likewise. >>> * calls.c (prepare_call_address): Remove SIBCALLP parameter and >>> add >>> FLAGS parameter. Deal with indirect calls by descriptor and >>> adjust. >>> Set STATIC_CHAIN_REG_P on the static chain register, if any. >>> (call_expr_flags): Set ECF_BY_DESCRIPTOR for calls by >>> descriptor. >>> (expand_call): Likewise. Move around call to >>> prepare_call_address >>> and pass all flags to it. >>> * cfgexpand.c (expand_call_stmt): Reinstate >>> CALL_EXPR_BY_DESCRIPTOR. >>> * gimple.h (enum gf_mask): New GF_CALL_BY_DESCRIPTOR value. >>> (gimple_call_set_by_descriptor): New setter. >>> (gimple_call_by_descriptor_p): New getter. >>> * gimple.c (gimple_build_call_from_tree): >>> SetCALL_EXPR_BY_DESCRIPTOR. >>> (gimple_call_flags): Deal with GF_CALL_BY_DESCRIPTOR. >>> * langhooks.h (struct lang_hooks): Add >>> custom_function_descriptors. >>> * langhooks-def.h (LANG_HOOKS_CUSTOM_FUNCTION_DESCRIPTORS): >>> Define. >>> (LANG_HOOKS_INITIALIZER): Add >>> LANG_HOOKS_CUSTOM_FUNCTION_DESCRIPTORS. >>> * rtl.h (STATIC_CHAIN_REG_P): New macro. >>> * rtlanal.c (find_first_parameter_load): Skip static chain >>> registers. >>> * target.def (custom_function_descriptors): New POD hook. >>> * tree.h (FUNC_ADDR_BY_DESCRIPTOR): New flag on ADDR_EXPR. >>> (CALL_EXPR_BY_DESCRIPTOR): New flag on CALL_EXPR. >>> * tree-core.h (ECF_BY_DESCRIPTOR): New mask. >>> Document FUNC_ADDR_BY_DESCRIPTOR and CALL_EXPR_BY_DESCRIPTOR. >>> * tree.c (make_node_stat) <tcc_declaration>: Use >>> FUNCTION_ALIGNMENT. >>> (build_common_builtin_nodes): Initialize init_descriptor and >>> adjust_descriptor. >>> * tree-nested.c: Include target.h. >>> (struct nesting_info): Add 'any_descr_created' field. >>> (get_descriptor_type): New function. >>> (lookup_element_for_decl): New function extracted from... >>> (create_field_for_decl): Likewise. >>> (lookup_tramp_for_decl): ...here. Adjust. >>> (lookup_descr_for_decl): New function. >>> (convert_tramp_reference_op): Deal with descriptors. >>> (build_init_call_stmt): New function extracted from... >>> (finalize_nesting_tree_1): ...here. Adjust and deal >>> withdescriptors. >>> * defaults.h (FUNCTION_ALIGNMENT): Define. >>> (TRAMPOLINE_ALIGNMENT): Set to above instead of >>> FUNCTION_BOUNDARY. >> >> According to https://golang.org/cl/18200, this change broke Go on PPC64le. >> >> I haven't investigated myself and I don't know why. Go does not use >> stack trampolines for function closures. It does use function >> closures, but they are built on the heap. It also uses closures >> mediated by libffi. The Go frontend does not enable custom function >> descriptors. >> >> It should be possible to recreate the problem by configuring with >> --enable-languages=go and running `make >> RUNTESTFLAGS="go-test.exp=recover.go" check-gcc-go`. >> >> Ian >> >> >
