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[/] [openrisc/] [trunk/] [gnu-dev/] [or1k-gcc/] [gcc/] [except.c] - Rev 796
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/* Implements exception handling. Copyright (C) 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc. Contributed by Mike Stump <mrs@cygnus.com>. This file is part of GCC. GCC is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version. GCC is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GCC; see the file COPYING3. If not see <http://www.gnu.org/licenses/>. */ /* An exception is an event that can be "thrown" from within a function. This event can then be "caught" by the callers of the function. The representation of exceptions changes several times during the compilation process: In the beginning, in the front end, we have the GENERIC trees TRY_CATCH_EXPR, TRY_FINALLY_EXPR, WITH_CLEANUP_EXPR, CLEANUP_POINT_EXPR, CATCH_EXPR, and EH_FILTER_EXPR. During initial gimplification (gimplify.c) these are lowered to the GIMPLE_TRY, GIMPLE_CATCH, and GIMPLE_EH_FILTER nodes. The WITH_CLEANUP_EXPR and CLEANUP_POINT_EXPR nodes are converted into GIMPLE_TRY_FINALLY nodes; the others are a more direct 1-1 conversion. During pass_lower_eh (tree-eh.c) we record the nested structure of the TRY nodes in EH_REGION nodes in CFUN->EH->REGION_TREE. We expand the eh_protect_cleanup_actions langhook into MUST_NOT_THROW regions at this time. We can then flatten the statements within the TRY nodes to straight-line code. Statements that had been within TRY nodes that can throw are recorded within CFUN->EH->THROW_STMT_TABLE, so that we may remember what action is supposed to be taken if a given statement does throw. During this lowering process, we create an EH_LANDING_PAD node for each EH_REGION that has some code within the function that needs to be executed if a throw does happen. We also create RESX statements that are used to transfer control from an inner EH_REGION to an outer EH_REGION. We also create EH_DISPATCH statements as placeholders for a runtime type comparison that should be made in order to select the action to perform among different CATCH and EH_FILTER regions. During pass_lower_eh_dispatch (tree-eh.c), which is run after all inlining is complete, we are able to run assign_filter_values, which allows us to map the set of types manipulated by all of the CATCH and EH_FILTER regions to a set of integers. This set of integers will be how the exception runtime communicates with the code generated within the function. We then expand the GIMPLE_EH_DISPATCH statements to a switch or conditional branches that use the argument provided by the runtime (__builtin_eh_filter) and the set of integers we computed in assign_filter_values. During pass_lower_resx (tree-eh.c), which is run near the end of optimization, we expand RESX statements. If the eh region that is outer to the RESX statement is a MUST_NOT_THROW, then the RESX expands to some form of abort statement. If the eh region that is outer to the RESX statement is within the current function, then the RESX expands to a bookkeeping call (__builtin_eh_copy_values) and a goto. Otherwise, the next handler for the exception must be within a function somewhere up the call chain, so we call back into the exception runtime (__builtin_unwind_resume). During pass_expand (cfgexpand.c), we generate REG_EH_REGION notes that create an rtl to eh_region mapping that corresponds to the gimple to eh_region mapping that had been recorded in the THROW_STMT_TABLE. During pass_rtl_eh (except.c), we generate the real landing pads to which the runtime will actually transfer control. These new landing pads perform whatever bookkeeping is needed by the target backend in order to resume execution within the current function. Each of these new landing pads falls through into the post_landing_pad label which had been used within the CFG up to this point. All exception edges within the CFG are redirected to the new landing pads. If the target uses setjmp to implement exceptions, the various extra calls into the runtime to register and unregister the current stack frame are emitted at this time. During pass_convert_to_eh_region_ranges (except.c), we transform the REG_EH_REGION notes attached to individual insns into non-overlapping ranges of insns bounded by NOTE_INSN_EH_REGION_BEG and NOTE_INSN_EH_REGION_END. Each insn within such ranges has the same associated action within the exception region tree, meaning that (1) the exception is caught by the same landing pad within the current function, (2) the exception is blocked by the runtime with a MUST_NOT_THROW region, or (3) the exception is not handled at all within the current function. Finally, during assembly generation, we call output_function_exception_table (except.c) to emit the tables with which the exception runtime can determine if a given stack frame handles a given exception, and if so what filter value to provide to the function when the non-local control transfer is effected. If the target uses dwarf2 unwinding to implement exceptions, then output_call_frame_info (dwarf2out.c) emits the required unwind data. */ #include "config.h" #include "system.h" #include "coretypes.h" #include "tm.h" #include "rtl.h" #include "tree.h" #include "flags.h" #include "function.h" #include "expr.h" #include "libfuncs.h" #include "insn-config.h" #include "except.h" #include "integrate.h" #include "hard-reg-set.h" #include "basic-block.h" #include "output.h" #include "dwarf2asm.h" #include "dwarf2out.h" #include "dwarf2.h" #include "toplev.h" #include "hashtab.h" #include "intl.h" #include "ggc.h" #include "tm_p.h" #include "target.h" #include "common/common-target.h" #include "langhooks.h" #include "cgraph.h" #include "diagnostic.h" #include "tree-pretty-print.h" #include "tree-pass.h" #include "timevar.h" #include "tree-flow.h" /* Provide defaults for stuff that may not be defined when using sjlj exceptions. */ #ifndef EH_RETURN_DATA_REGNO #define EH_RETURN_DATA_REGNO(N) INVALID_REGNUM #endif static GTY(()) int call_site_base; static GTY ((param_is (union tree_node))) htab_t type_to_runtime_map; /* Describe the SjLj_Function_Context structure. */ static GTY(()) tree sjlj_fc_type_node; static int sjlj_fc_call_site_ofs; static int sjlj_fc_data_ofs; static int sjlj_fc_personality_ofs; static int sjlj_fc_lsda_ofs; static int sjlj_fc_jbuf_ofs; struct GTY(()) call_site_record_d { rtx landing_pad; int action; }; static bool get_eh_region_and_lp_from_rtx (const_rtx, eh_region *, eh_landing_pad *); static int t2r_eq (const void *, const void *); static hashval_t t2r_hash (const void *); static int ttypes_filter_eq (const void *, const void *); static hashval_t ttypes_filter_hash (const void *); static int ehspec_filter_eq (const void *, const void *); static hashval_t ehspec_filter_hash (const void *); static int add_ttypes_entry (htab_t, tree); static int add_ehspec_entry (htab_t, htab_t, tree); static void dw2_build_landing_pads (void); static int action_record_eq (const void *, const void *); static hashval_t action_record_hash (const void *); static int add_action_record (htab_t, int, int); static int collect_one_action_chain (htab_t, eh_region); static int add_call_site (rtx, int, int); static void push_uleb128 (VEC (uchar, gc) **, unsigned int); static void push_sleb128 (VEC (uchar, gc) **, int); #ifndef HAVE_AS_LEB128 static int dw2_size_of_call_site_table (int); static int sjlj_size_of_call_site_table (void); #endif static void dw2_output_call_site_table (int, int); static void sjlj_output_call_site_table (void); void init_eh (void) { if (! flag_exceptions) return; type_to_runtime_map = htab_create_ggc (31, t2r_hash, t2r_eq, NULL); /* Create the SjLj_Function_Context structure. This should match the definition in unwind-sjlj.c. */ if (targetm_common.except_unwind_info (&global_options) == UI_SJLJ) { tree f_jbuf, f_per, f_lsda, f_prev, f_cs, f_data, tmp; sjlj_fc_type_node = lang_hooks.types.make_type (RECORD_TYPE); f_prev = build_decl (BUILTINS_LOCATION, FIELD_DECL, get_identifier ("__prev"), build_pointer_type (sjlj_fc_type_node)); DECL_FIELD_CONTEXT (f_prev) = sjlj_fc_type_node; f_cs = build_decl (BUILTINS_LOCATION, FIELD_DECL, get_identifier ("__call_site"), integer_type_node); DECL_FIELD_CONTEXT (f_cs) = sjlj_fc_type_node; tmp = build_index_type (size_int (4 - 1)); tmp = build_array_type (lang_hooks.types.type_for_mode (targetm.unwind_word_mode (), 1), tmp); f_data = build_decl (BUILTINS_LOCATION, FIELD_DECL, get_identifier ("__data"), tmp); DECL_FIELD_CONTEXT (f_data) = sjlj_fc_type_node; f_per = build_decl (BUILTINS_LOCATION, FIELD_DECL, get_identifier ("__personality"), ptr_type_node); DECL_FIELD_CONTEXT (f_per) = sjlj_fc_type_node; f_lsda = build_decl (BUILTINS_LOCATION, FIELD_DECL, get_identifier ("__lsda"), ptr_type_node); DECL_FIELD_CONTEXT (f_lsda) = sjlj_fc_type_node; #ifdef DONT_USE_BUILTIN_SETJMP #ifdef JMP_BUF_SIZE tmp = size_int (JMP_BUF_SIZE - 1); #else /* Should be large enough for most systems, if it is not, JMP_BUF_SIZE should be defined with the proper value. It will also tend to be larger than necessary for most systems, a more optimal port will define JMP_BUF_SIZE. */ tmp = size_int (FIRST_PSEUDO_REGISTER + 2 - 1); #endif #else /* builtin_setjmp takes a pointer to 5 words. */ tmp = size_int (5 * BITS_PER_WORD / POINTER_SIZE - 1); #endif tmp = build_index_type (tmp); tmp = build_array_type (ptr_type_node, tmp); f_jbuf = build_decl (BUILTINS_LOCATION, FIELD_DECL, get_identifier ("__jbuf"), tmp); #ifdef DONT_USE_BUILTIN_SETJMP /* We don't know what the alignment requirements of the runtime's jmp_buf has. Overestimate. */ DECL_ALIGN (f_jbuf) = BIGGEST_ALIGNMENT; DECL_USER_ALIGN (f_jbuf) = 1; #endif DECL_FIELD_CONTEXT (f_jbuf) = sjlj_fc_type_node; TYPE_FIELDS (sjlj_fc_type_node) = f_prev; TREE_CHAIN (f_prev) = f_cs; TREE_CHAIN (f_cs) = f_data; TREE_CHAIN (f_data) = f_per; TREE_CHAIN (f_per) = f_lsda; TREE_CHAIN (f_lsda) = f_jbuf; layout_type (sjlj_fc_type_node); /* Cache the interesting field offsets so that we have easy access from rtl. */ sjlj_fc_call_site_ofs = (tree_low_cst (DECL_FIELD_OFFSET (f_cs), 1) + tree_low_cst (DECL_FIELD_BIT_OFFSET (f_cs), 1) / BITS_PER_UNIT); sjlj_fc_data_ofs = (tree_low_cst (DECL_FIELD_OFFSET (f_data), 1) + tree_low_cst (DECL_FIELD_BIT_OFFSET (f_data), 1) / BITS_PER_UNIT); sjlj_fc_personality_ofs = (tree_low_cst (DECL_FIELD_OFFSET (f_per), 1) + tree_low_cst (DECL_FIELD_BIT_OFFSET (f_per), 1) / BITS_PER_UNIT); sjlj_fc_lsda_ofs = (tree_low_cst (DECL_FIELD_OFFSET (f_lsda), 1) + tree_low_cst (DECL_FIELD_BIT_OFFSET (f_lsda), 1) / BITS_PER_UNIT); sjlj_fc_jbuf_ofs = (tree_low_cst (DECL_FIELD_OFFSET (f_jbuf), 1) + tree_low_cst (DECL_FIELD_BIT_OFFSET (f_jbuf), 1) / BITS_PER_UNIT); } } void init_eh_for_function (void) { cfun->eh = ggc_alloc_cleared_eh_status (); /* Make sure zero'th entries are used. */ VEC_safe_push (eh_region, gc, cfun->eh->region_array, NULL); VEC_safe_push (eh_landing_pad, gc, cfun->eh->lp_array, NULL); } /* Routines to generate the exception tree somewhat directly. These are used from tree-eh.c when processing exception related nodes during tree optimization. */ static eh_region gen_eh_region (enum eh_region_type type, eh_region outer) { eh_region new_eh; /* Insert a new blank region as a leaf in the tree. */ new_eh = ggc_alloc_cleared_eh_region_d (); new_eh->type = type; new_eh->outer = outer; if (outer) { new_eh->next_peer = outer->inner; outer->inner = new_eh; } else { new_eh->next_peer = cfun->eh->region_tree; cfun->eh->region_tree = new_eh; } new_eh->index = VEC_length (eh_region, cfun->eh->region_array); VEC_safe_push (eh_region, gc, cfun->eh->region_array, new_eh); /* Copy the language's notion of whether to use __cxa_end_cleanup. */ if (targetm.arm_eabi_unwinder && lang_hooks.eh_use_cxa_end_cleanup) new_eh->use_cxa_end_cleanup = true; return new_eh; } eh_region gen_eh_region_cleanup (eh_region outer) { return gen_eh_region (ERT_CLEANUP, outer); } eh_region gen_eh_region_try (eh_region outer) { return gen_eh_region (ERT_TRY, outer); } eh_catch gen_eh_region_catch (eh_region t, tree type_or_list) { eh_catch c, l; tree type_list, type_node; gcc_assert (t->type == ERT_TRY); /* Ensure to always end up with a type list to normalize further processing, then register each type against the runtime types map. */ type_list = type_or_list; if (type_or_list) { if (TREE_CODE (type_or_list) != TREE_LIST) type_list = tree_cons (NULL_TREE, type_or_list, NULL_TREE); type_node = type_list; for (; type_node; type_node = TREE_CHAIN (type_node)) add_type_for_runtime (TREE_VALUE (type_node)); } c = ggc_alloc_cleared_eh_catch_d (); c->type_list = type_list; l = t->u.eh_try.last_catch; c->prev_catch = l; if (l) l->next_catch = c; else t->u.eh_try.first_catch = c; t->u.eh_try.last_catch = c; return c; } eh_region gen_eh_region_allowed (eh_region outer, tree allowed) { eh_region region = gen_eh_region (ERT_ALLOWED_EXCEPTIONS, outer); region->u.allowed.type_list = allowed; for (; allowed ; allowed = TREE_CHAIN (allowed)) add_type_for_runtime (TREE_VALUE (allowed)); return region; } eh_region gen_eh_region_must_not_throw (eh_region outer) { return gen_eh_region (ERT_MUST_NOT_THROW, outer); } eh_landing_pad gen_eh_landing_pad (eh_region region) { eh_landing_pad lp = ggc_alloc_cleared_eh_landing_pad_d (); lp->next_lp = region->landing_pads; lp->region = region; lp->index = VEC_length (eh_landing_pad, cfun->eh->lp_array); region->landing_pads = lp; VEC_safe_push (eh_landing_pad, gc, cfun->eh->lp_array, lp); return lp; } eh_region get_eh_region_from_number_fn (struct function *ifun, int i) { return VEC_index (eh_region, ifun->eh->region_array, i); } eh_region get_eh_region_from_number (int i) { return get_eh_region_from_number_fn (cfun, i); } eh_landing_pad get_eh_landing_pad_from_number_fn (struct function *ifun, int i) { return VEC_index (eh_landing_pad, ifun->eh->lp_array, i); } eh_landing_pad get_eh_landing_pad_from_number (int i) { return get_eh_landing_pad_from_number_fn (cfun, i); } eh_region get_eh_region_from_lp_number_fn (struct function *ifun, int i) { if (i < 0) return VEC_index (eh_region, ifun->eh->region_array, -i); else if (i == 0) return NULL; else { eh_landing_pad lp; lp = VEC_index (eh_landing_pad, ifun->eh->lp_array, i); return lp->region; } } eh_region get_eh_region_from_lp_number (int i) { return get_eh_region_from_lp_number_fn (cfun, i); } /* Returns true if the current function has exception handling regions. */ bool current_function_has_exception_handlers (void) { return cfun->eh->region_tree != NULL; } /* A subroutine of duplicate_eh_regions. Copy the eh_region tree at OLD. Root it at OUTER, and apply LP_OFFSET to the lp numbers. */ struct duplicate_eh_regions_data { duplicate_eh_regions_map label_map; void *label_map_data; struct pointer_map_t *eh_map; }; static void duplicate_eh_regions_1 (struct duplicate_eh_regions_data *data, eh_region old_r, eh_region outer) { eh_landing_pad old_lp, new_lp; eh_region new_r; void **slot; new_r = gen_eh_region (old_r->type, outer); slot = pointer_map_insert (data->eh_map, (void *)old_r); gcc_assert (*slot == NULL); *slot = (void *)new_r; switch (old_r->type) { case ERT_CLEANUP: break; case ERT_TRY: { eh_catch oc, nc; for (oc = old_r->u.eh_try.first_catch; oc ; oc = oc->next_catch) { /* We should be doing all our region duplication before and during inlining, which is before filter lists are created. */ gcc_assert (oc->filter_list == NULL); nc = gen_eh_region_catch (new_r, oc->type_list); nc->label = data->label_map (oc->label, data->label_map_data); } } break; case ERT_ALLOWED_EXCEPTIONS: new_r->u.allowed.type_list = old_r->u.allowed.type_list; if (old_r->u.allowed.label) new_r->u.allowed.label = data->label_map (old_r->u.allowed.label, data->label_map_data); else new_r->u.allowed.label = NULL_TREE; break; case ERT_MUST_NOT_THROW: new_r->u.must_not_throw = old_r->u.must_not_throw; break; } for (old_lp = old_r->landing_pads; old_lp ; old_lp = old_lp->next_lp) { /* Don't bother copying unused landing pads. */ if (old_lp->post_landing_pad == NULL) continue; new_lp = gen_eh_landing_pad (new_r); slot = pointer_map_insert (data->eh_map, (void *)old_lp); gcc_assert (*slot == NULL); *slot = (void *)new_lp; new_lp->post_landing_pad = data->label_map (old_lp->post_landing_pad, data->label_map_data); EH_LANDING_PAD_NR (new_lp->post_landing_pad) = new_lp->index; } /* Make sure to preserve the original use of __cxa_end_cleanup. */ new_r->use_cxa_end_cleanup = old_r->use_cxa_end_cleanup; for (old_r = old_r->inner; old_r ; old_r = old_r->next_peer) duplicate_eh_regions_1 (data, old_r, new_r); } /* Duplicate the EH regions from IFUN rooted at COPY_REGION into the current function and root the tree below OUTER_REGION. The special case of COPY_REGION of NULL means all regions. Remap labels using MAP/MAP_DATA callback. Return a pointer map that allows the caller to remap uses of both EH regions and EH landing pads. */ struct pointer_map_t * duplicate_eh_regions (struct function *ifun, eh_region copy_region, int outer_lp, duplicate_eh_regions_map map, void *map_data) { struct duplicate_eh_regions_data data; eh_region outer_region; #ifdef ENABLE_CHECKING verify_eh_tree (ifun); #endif data.label_map = map; data.label_map_data = map_data; data.eh_map = pointer_map_create (); outer_region = get_eh_region_from_lp_number (outer_lp); /* Copy all the regions in the subtree. */ if (copy_region) duplicate_eh_regions_1 (&data, copy_region, outer_region); else { eh_region r; for (r = ifun->eh->region_tree; r ; r = r->next_peer) duplicate_eh_regions_1 (&data, r, outer_region); } #ifdef ENABLE_CHECKING verify_eh_tree (cfun); #endif return data.eh_map; } /* Return the region that is outer to both REGION_A and REGION_B in IFUN. */ eh_region eh_region_outermost (struct function *ifun, eh_region region_a, eh_region region_b) { sbitmap b_outer; gcc_assert (ifun->eh->region_array); gcc_assert (ifun->eh->region_tree); b_outer = sbitmap_alloc (VEC_length (eh_region, ifun->eh->region_array)); sbitmap_zero (b_outer); do { SET_BIT (b_outer, region_b->index); region_b = region_b->outer; } while (region_b); do { if (TEST_BIT (b_outer, region_a->index)) break; region_a = region_a->outer; } while (region_a); sbitmap_free (b_outer); return region_a; } static int t2r_eq (const void *pentry, const void *pdata) { const_tree const entry = (const_tree) pentry; const_tree const data = (const_tree) pdata; return TREE_PURPOSE (entry) == data; } static hashval_t t2r_hash (const void *pentry) { const_tree const entry = (const_tree) pentry; return TREE_HASH (TREE_PURPOSE (entry)); } void add_type_for_runtime (tree type) { tree *slot; /* If TYPE is NOP_EXPR, it means that it already is a runtime type. */ if (TREE_CODE (type) == NOP_EXPR) return; slot = (tree *) htab_find_slot_with_hash (type_to_runtime_map, type, TREE_HASH (type), INSERT); if (*slot == NULL) { tree runtime = lang_hooks.eh_runtime_type (type); *slot = tree_cons (type, runtime, NULL_TREE); } } tree lookup_type_for_runtime (tree type) { tree *slot; /* If TYPE is NOP_EXPR, it means that it already is a runtime type. */ if (TREE_CODE (type) == NOP_EXPR) return type; slot = (tree *) htab_find_slot_with_hash (type_to_runtime_map, type, TREE_HASH (type), NO_INSERT); /* We should have always inserted the data earlier. */ return TREE_VALUE (*slot); } /* Represent an entry in @TTypes for either catch actions or exception filter actions. */ struct ttypes_filter { tree t; int filter; }; /* Compare ENTRY (a ttypes_filter entry in the hash table) with DATA (a tree) for a @TTypes type node we are thinking about adding. */ static int ttypes_filter_eq (const void *pentry, const void *pdata) { const struct ttypes_filter *const entry = (const struct ttypes_filter *) pentry; const_tree const data = (const_tree) pdata; return entry->t == data; } static hashval_t ttypes_filter_hash (const void *pentry) { const struct ttypes_filter *entry = (const struct ttypes_filter *) pentry; return TREE_HASH (entry->t); } /* Compare ENTRY with DATA (both struct ttypes_filter) for a @TTypes exception specification list we are thinking about adding. */ /* ??? Currently we use the type lists in the order given. Someone should put these in some canonical order. */ static int ehspec_filter_eq (const void *pentry, const void *pdata) { const struct ttypes_filter *entry = (const struct ttypes_filter *) pentry; const struct ttypes_filter *data = (const struct ttypes_filter *) pdata; return type_list_equal (entry->t, data->t); } /* Hash function for exception specification lists. */ static hashval_t ehspec_filter_hash (const void *pentry) { const struct ttypes_filter *entry = (const struct ttypes_filter *) pentry; hashval_t h = 0; tree list; for (list = entry->t; list ; list = TREE_CHAIN (list)) h = (h << 5) + (h >> 27) + TREE_HASH (TREE_VALUE (list)); return h; } /* Add TYPE (which may be NULL) to cfun->eh->ttype_data, using TYPES_HASH to speed up the search. Return the filter value to be used. */ static int add_ttypes_entry (htab_t ttypes_hash, tree type) { struct ttypes_filter **slot, *n; slot = (struct ttypes_filter **) htab_find_slot_with_hash (ttypes_hash, type, TREE_HASH (type), INSERT); if ((n = *slot) == NULL) { /* Filter value is a 1 based table index. */ n = XNEW (struct ttypes_filter); n->t = type; n->filter = VEC_length (tree, cfun->eh->ttype_data) + 1; *slot = n; VEC_safe_push (tree, gc, cfun->eh->ttype_data, type); } return n->filter; } /* Add LIST to cfun->eh->ehspec_data, using EHSPEC_HASH and TYPES_HASH to speed up the search. Return the filter value to be used. */ static int add_ehspec_entry (htab_t ehspec_hash, htab_t ttypes_hash, tree list) { struct ttypes_filter **slot, *n; struct ttypes_filter dummy; dummy.t = list; slot = (struct ttypes_filter **) htab_find_slot (ehspec_hash, &dummy, INSERT); if ((n = *slot) == NULL) { int len; if (targetm.arm_eabi_unwinder) len = VEC_length (tree, cfun->eh->ehspec_data.arm_eabi); else len = VEC_length (uchar, cfun->eh->ehspec_data.other); /* Filter value is a -1 based byte index into a uleb128 buffer. */ n = XNEW (struct ttypes_filter); n->t = list; n->filter = -(len + 1); *slot = n; /* Generate a 0 terminated list of filter values. */ for (; list ; list = TREE_CHAIN (list)) { if (targetm.arm_eabi_unwinder) VEC_safe_push (tree, gc, cfun->eh->ehspec_data.arm_eabi, TREE_VALUE (list)); else { /* Look up each type in the list and encode its filter value as a uleb128. */ push_uleb128 (&cfun->eh->ehspec_data.other, add_ttypes_entry (ttypes_hash, TREE_VALUE (list))); } } if (targetm.arm_eabi_unwinder) VEC_safe_push (tree, gc, cfun->eh->ehspec_data.arm_eabi, NULL_TREE); else VEC_safe_push (uchar, gc, cfun->eh->ehspec_data.other, 0); } return n->filter; } /* Generate the action filter values to be used for CATCH and ALLOWED_EXCEPTIONS regions. When using dwarf2 exception regions, we use lots of landing pads, and so every type or list can share the same filter value, which saves table space. */ void assign_filter_values (void) { int i; htab_t ttypes, ehspec; eh_region r; eh_catch c; cfun->eh->ttype_data = VEC_alloc (tree, gc, 16); if (targetm.arm_eabi_unwinder) cfun->eh->ehspec_data.arm_eabi = VEC_alloc (tree, gc, 64); else cfun->eh->ehspec_data.other = VEC_alloc (uchar, gc, 64); ttypes = htab_create (31, ttypes_filter_hash, ttypes_filter_eq, free); ehspec = htab_create (31, ehspec_filter_hash, ehspec_filter_eq, free); for (i = 1; VEC_iterate (eh_region, cfun->eh->region_array, i, r); ++i) { if (r == NULL) continue; switch (r->type) { case ERT_TRY: for (c = r->u.eh_try.first_catch; c ; c = c->next_catch) { /* Whatever type_list is (NULL or true list), we build a list of filters for the region. */ c->filter_list = NULL_TREE; if (c->type_list != NULL) { /* Get a filter value for each of the types caught and store them in the region's dedicated list. */ tree tp_node = c->type_list; for ( ; tp_node; tp_node = TREE_CHAIN (tp_node)) { int flt = add_ttypes_entry (ttypes, TREE_VALUE (tp_node)); tree flt_node = build_int_cst (integer_type_node, flt); c->filter_list = tree_cons (NULL_TREE, flt_node, c->filter_list); } } else { /* Get a filter value for the NULL list also since it will need an action record anyway. */ int flt = add_ttypes_entry (ttypes, NULL); tree flt_node = build_int_cst (integer_type_node, flt); c->filter_list = tree_cons (NULL_TREE, flt_node, NULL); } } break; case ERT_ALLOWED_EXCEPTIONS: r->u.allowed.filter = add_ehspec_entry (ehspec, ttypes, r->u.allowed.type_list); break; default: break; } } htab_delete (ttypes); htab_delete (ehspec); } /* Emit SEQ into basic block just before INSN (that is assumed to be first instruction of some existing BB and return the newly produced block. */ static basic_block emit_to_new_bb_before (rtx seq, rtx insn) { rtx last; basic_block bb; edge e; edge_iterator ei; /* If there happens to be a fallthru edge (possibly created by cleanup_cfg call), we don't want it to go into newly created landing pad or other EH construct. */ for (ei = ei_start (BLOCK_FOR_INSN (insn)->preds); (e = ei_safe_edge (ei)); ) if (e->flags & EDGE_FALLTHRU) force_nonfallthru (e); else ei_next (&ei); last = emit_insn_before (seq, insn); if (BARRIER_P (last)) last = PREV_INSN (last); bb = create_basic_block (seq, last, BLOCK_FOR_INSN (insn)->prev_bb); update_bb_for_insn (bb); bb->flags |= BB_SUPERBLOCK; return bb; } /* A subroutine of dw2_build_landing_pads, also used for edge splitting at the rtl level. Emit the code required by the target at a landing pad for the given region. */ void expand_dw2_landing_pad_for_region (eh_region region) { #ifdef HAVE_exception_receiver if (HAVE_exception_receiver) emit_insn (gen_exception_receiver ()); else #endif #ifdef HAVE_nonlocal_goto_receiver if (HAVE_nonlocal_goto_receiver) emit_insn (gen_nonlocal_goto_receiver ()); else #endif { /* Nothing */ } if (region->exc_ptr_reg) emit_move_insn (region->exc_ptr_reg, gen_rtx_REG (ptr_mode, EH_RETURN_DATA_REGNO (0))); if (region->filter_reg) emit_move_insn (region->filter_reg, gen_rtx_REG (targetm.eh_return_filter_mode (), EH_RETURN_DATA_REGNO (1))); } /* Expand the extra code needed at landing pads for dwarf2 unwinding. */ static void dw2_build_landing_pads (void) { int i; eh_landing_pad lp; int e_flags = EDGE_FALLTHRU; /* If we're going to partition blocks, we need to be able to add new landing pads later, which means that we need to hold on to the post-landing-pad block. Prevent it from being merged away. We'll remove this bit after partitioning. */ if (flag_reorder_blocks_and_partition) e_flags |= EDGE_PRESERVE; for (i = 1; VEC_iterate (eh_landing_pad, cfun->eh->lp_array, i, lp); ++i) { basic_block bb; rtx seq; edge e; if (lp == NULL || lp->post_landing_pad == NULL) continue; start_sequence (); lp->landing_pad = gen_label_rtx (); emit_label (lp->landing_pad); LABEL_PRESERVE_P (lp->landing_pad) = 1; expand_dw2_landing_pad_for_region (lp->region); seq = get_insns (); end_sequence (); bb = emit_to_new_bb_before (seq, label_rtx (lp->post_landing_pad)); e = make_edge (bb, bb->next_bb, e_flags); e->count = bb->count; e->probability = REG_BR_PROB_BASE; } } static VEC (int, heap) *sjlj_lp_call_site_index; /* Process all active landing pads. Assign each one a compact dispatch index, and a call-site index. */ static int sjlj_assign_call_site_values (void) { htab_t ar_hash; int i, disp_index; eh_landing_pad lp; crtl->eh.action_record_data = VEC_alloc (uchar, gc, 64); ar_hash = htab_create (31, action_record_hash, action_record_eq, free); disp_index = 0; call_site_base = 1; for (i = 1; VEC_iterate (eh_landing_pad, cfun->eh->lp_array, i, lp); ++i) if (lp && lp->post_landing_pad) { int action, call_site; /* First: build the action table. */ action = collect_one_action_chain (ar_hash, lp->region); /* Next: assign call-site values. If dwarf2 terms, this would be the region number assigned by convert_to_eh_region_ranges, but handles no-action and must-not-throw differently. */ /* Map must-not-throw to otherwise unused call-site index 0. */ if (action == -2) call_site = 0; /* Map no-action to otherwise unused call-site index -1. */ else if (action == -1) call_site = -1; /* Otherwise, look it up in the table. */ else call_site = add_call_site (GEN_INT (disp_index), action, 0); VEC_replace (int, sjlj_lp_call_site_index, i, call_site); disp_index++; } htab_delete (ar_hash); return disp_index; } /* Emit code to record the current call-site index before every insn that can throw. */ static void sjlj_mark_call_sites (void) { int last_call_site = -2; rtx insn, mem; for (insn = get_insns (); insn ; insn = NEXT_INSN (insn)) { eh_landing_pad lp; eh_region r; bool nothrow; int this_call_site; rtx before, p; /* Reset value tracking at extended basic block boundaries. */ if (LABEL_P (insn)) last_call_site = -2; if (! INSN_P (insn)) continue; nothrow = get_eh_region_and_lp_from_rtx (insn, &r, &lp); if (nothrow) continue; if (lp) this_call_site = VEC_index (int, sjlj_lp_call_site_index, lp->index); else if (r == NULL) { /* Calls (and trapping insns) without notes are outside any exception handling region in this function. Mark them as no action. */ this_call_site = -1; } else { gcc_assert (r->type == ERT_MUST_NOT_THROW); this_call_site = 0; } if (this_call_site != -1) crtl->uses_eh_lsda = 1; if (this_call_site == last_call_site) continue; /* Don't separate a call from it's argument loads. */ before = insn; if (CALL_P (insn)) before = find_first_parameter_load (insn, NULL_RTX); start_sequence (); mem = adjust_address (crtl->eh.sjlj_fc, TYPE_MODE (integer_type_node), sjlj_fc_call_site_ofs); emit_move_insn (mem, GEN_INT (this_call_site)); p = get_insns (); end_sequence (); emit_insn_before (p, before); last_call_site = this_call_site; } } /* Construct the SjLj_Function_Context. */ static void sjlj_emit_function_enter (rtx dispatch_label) { rtx fn_begin, fc, mem, seq; bool fn_begin_outside_block; rtx personality = get_personality_function (current_function_decl); fc = crtl->eh.sjlj_fc; start_sequence (); /* We're storing this libcall's address into memory instead of calling it directly. Thus, we must call assemble_external_libcall here, as we can not depend on emit_library_call to do it for us. */ assemble_external_libcall (personality); mem = adjust_address (fc, Pmode, sjlj_fc_personality_ofs); emit_move_insn (mem, personality); mem = adjust_address (fc, Pmode, sjlj_fc_lsda_ofs); if (crtl->uses_eh_lsda) { char buf[20]; rtx sym; ASM_GENERATE_INTERNAL_LABEL (buf, "LLSDA", current_function_funcdef_no); sym = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (buf)); SYMBOL_REF_FLAGS (sym) = SYMBOL_FLAG_LOCAL; emit_move_insn (mem, sym); } else emit_move_insn (mem, const0_rtx); if (dispatch_label) { #ifdef DONT_USE_BUILTIN_SETJMP rtx x, last; x = emit_library_call_value (setjmp_libfunc, NULL_RTX, LCT_RETURNS_TWICE, TYPE_MODE (integer_type_node), 1, plus_constant (XEXP (fc, 0), sjlj_fc_jbuf_ofs), Pmode); emit_cmp_and_jump_insns (x, const0_rtx, NE, 0, TYPE_MODE (integer_type_node), 0, dispatch_label); last = get_last_insn (); if (JUMP_P (last) && any_condjump_p (last)) { gcc_assert (!find_reg_note (last, REG_BR_PROB, 0)); add_reg_note (last, REG_BR_PROB, GEN_INT (REG_BR_PROB_BASE / 100)); } #else expand_builtin_setjmp_setup (plus_constant (XEXP (fc, 0), sjlj_fc_jbuf_ofs), dispatch_label); #endif } emit_library_call (unwind_sjlj_register_libfunc, LCT_NORMAL, VOIDmode, 1, XEXP (fc, 0), Pmode); seq = get_insns (); end_sequence (); /* ??? Instead of doing this at the beginning of the function, do this in a block that is at loop level 0 and dominates all can_throw_internal instructions. */ fn_begin_outside_block = true; for (fn_begin = get_insns (); ; fn_begin = NEXT_INSN (fn_begin)) if (NOTE_P (fn_begin)) { if (NOTE_KIND (fn_begin) == NOTE_INSN_FUNCTION_BEG) break; else if (NOTE_INSN_BASIC_BLOCK_P (fn_begin)) fn_begin_outside_block = false; } if (fn_begin_outside_block) insert_insn_on_edge (seq, single_succ_edge (ENTRY_BLOCK_PTR)); else emit_insn_after (seq, fn_begin); } /* Call back from expand_function_end to know where we should put the call to unwind_sjlj_unregister_libfunc if needed. */ void sjlj_emit_function_exit_after (rtx after) { crtl->eh.sjlj_exit_after = after; } static void sjlj_emit_function_exit (void) { rtx seq, insn; start_sequence (); emit_library_call (unwind_sjlj_unregister_libfunc, LCT_NORMAL, VOIDmode, 1, XEXP (crtl->eh.sjlj_fc, 0), Pmode); seq = get_insns (); end_sequence (); /* ??? Really this can be done in any block at loop level 0 that post-dominates all can_throw_internal instructions. This is the last possible moment. */ insn = crtl->eh.sjlj_exit_after; if (LABEL_P (insn)) insn = NEXT_INSN (insn); emit_insn_after (seq, insn); } static void sjlj_emit_dispatch_table (rtx dispatch_label, int num_dispatch) { enum machine_mode unwind_word_mode = targetm.unwind_word_mode (); enum machine_mode filter_mode = targetm.eh_return_filter_mode (); eh_landing_pad lp; rtx mem, seq, fc, before, exc_ptr_reg, filter_reg; rtx first_reachable_label; basic_block bb; eh_region r; edge e; int i, disp_index; gimple switch_stmt; fc = crtl->eh.sjlj_fc; start_sequence (); emit_label (dispatch_label); #ifndef DONT_USE_BUILTIN_SETJMP expand_builtin_setjmp_receiver (dispatch_label); /* The caller of expand_builtin_setjmp_receiver is responsible for making sure that the label doesn't vanish. The only other caller is the expander for __builtin_setjmp_receiver, which places this label on the nonlocal_goto_label list. Since we're modeling these CFG edges more exactly, we can use the forced_labels list instead. */ LABEL_PRESERVE_P (dispatch_label) = 1; forced_labels = gen_rtx_EXPR_LIST (VOIDmode, dispatch_label, forced_labels); #endif /* Load up exc_ptr and filter values from the function context. */ mem = adjust_address (fc, unwind_word_mode, sjlj_fc_data_ofs); if (unwind_word_mode != ptr_mode) { #ifdef POINTERS_EXTEND_UNSIGNED mem = convert_memory_address (ptr_mode, mem); #else mem = convert_to_mode (ptr_mode, mem, 0); #endif } exc_ptr_reg = force_reg (ptr_mode, mem); mem = adjust_address (fc, unwind_word_mode, sjlj_fc_data_ofs + GET_MODE_SIZE (unwind_word_mode)); if (unwind_word_mode != filter_mode) mem = convert_to_mode (filter_mode, mem, 0); filter_reg = force_reg (filter_mode, mem); /* Jump to one of the directly reachable regions. */ disp_index = 0; first_reachable_label = NULL; /* If there's exactly one call site in the function, don't bother generating a switch statement. */ switch_stmt = NULL; if (num_dispatch > 1) { tree disp; mem = adjust_address (fc, TYPE_MODE (integer_type_node), sjlj_fc_call_site_ofs); disp = make_tree (integer_type_node, mem); switch_stmt = gimple_build_switch_nlabels (num_dispatch, disp, NULL); } for (i = 1; VEC_iterate (eh_landing_pad, cfun->eh->lp_array, i, lp); ++i) if (lp && lp->post_landing_pad) { rtx seq2, label; start_sequence (); lp->landing_pad = dispatch_label; if (num_dispatch > 1) { tree t_label, case_elt, t; t_label = create_artificial_label (UNKNOWN_LOCATION); t = build_int_cst (integer_type_node, disp_index); case_elt = build_case_label (t, NULL, t_label); gimple_switch_set_label (switch_stmt, disp_index, case_elt); label = label_rtx (t_label); } else label = gen_label_rtx (); if (disp_index == 0) first_reachable_label = label; emit_label (label); r = lp->region; if (r->exc_ptr_reg) emit_move_insn (r->exc_ptr_reg, exc_ptr_reg); if (r->filter_reg) emit_move_insn (r->filter_reg, filter_reg); seq2 = get_insns (); end_sequence (); before = label_rtx (lp->post_landing_pad); bb = emit_to_new_bb_before (seq2, before); e = make_edge (bb, bb->next_bb, EDGE_FALLTHRU); e->count = bb->count; e->probability = REG_BR_PROB_BASE; disp_index++; } gcc_assert (disp_index == num_dispatch); if (num_dispatch > 1) { expand_case (switch_stmt); expand_builtin_trap (); } seq = get_insns (); end_sequence (); bb = emit_to_new_bb_before (seq, first_reachable_label); if (num_dispatch == 1) { e = make_edge (bb, bb->next_bb, EDGE_FALLTHRU); e->count = bb->count; e->probability = REG_BR_PROB_BASE; } } static void sjlj_build_landing_pads (void) { int num_dispatch; num_dispatch = VEC_length (eh_landing_pad, cfun->eh->lp_array); if (num_dispatch == 0) return; VEC_safe_grow (int, heap, sjlj_lp_call_site_index, num_dispatch); num_dispatch = sjlj_assign_call_site_values (); if (num_dispatch > 0) { rtx dispatch_label = gen_label_rtx (); int align = STACK_SLOT_ALIGNMENT (sjlj_fc_type_node, TYPE_MODE (sjlj_fc_type_node), TYPE_ALIGN (sjlj_fc_type_node)); crtl->eh.sjlj_fc = assign_stack_local (TYPE_MODE (sjlj_fc_type_node), int_size_in_bytes (sjlj_fc_type_node), align); sjlj_mark_call_sites (); sjlj_emit_function_enter (dispatch_label); sjlj_emit_dispatch_table (dispatch_label, num_dispatch); sjlj_emit_function_exit (); } /* If we do not have any landing pads, we may still need to register a personality routine and (empty) LSDA to handle must-not-throw regions. */ else if (function_needs_eh_personality (cfun) != eh_personality_none) { int align = STACK_SLOT_ALIGNMENT (sjlj_fc_type_node, TYPE_MODE (sjlj_fc_type_node), TYPE_ALIGN (sjlj_fc_type_node)); crtl->eh.sjlj_fc = assign_stack_local (TYPE_MODE (sjlj_fc_type_node), int_size_in_bytes (sjlj_fc_type_node), align); sjlj_mark_call_sites (); sjlj_emit_function_enter (NULL_RTX); sjlj_emit_function_exit (); } VEC_free (int, heap, sjlj_lp_call_site_index); } /* After initial rtl generation, call back to finish generating exception support code. */ static void finish_eh_generation (void) { basic_block bb; /* Construct the landing pads. */ if (targetm_common.except_unwind_info (&global_options) == UI_SJLJ) sjlj_build_landing_pads (); else dw2_build_landing_pads (); break_superblocks (); if (targetm_common.except_unwind_info (&global_options) == UI_SJLJ /* Kludge for Alpha/Tru64 (see alpha_gp_save_rtx). */ || single_succ_edge (ENTRY_BLOCK_PTR)->insns.r) commit_edge_insertions (); /* Redirect all EH edges from the post_landing_pad to the landing pad. */ FOR_EACH_BB (bb) { eh_landing_pad lp; edge_iterator ei; edge e; lp = get_eh_landing_pad_from_rtx (BB_END (bb)); FOR_EACH_EDGE (e, ei, bb->succs) if (e->flags & EDGE_EH) break; /* We should not have generated any new throwing insns during this pass, and we should not have lost any EH edges, so we only need to handle two cases here: (1) reachable handler and an existing edge to post-landing-pad, (2) no reachable handler and no edge. */ gcc_assert ((lp != NULL) == (e != NULL)); if (lp != NULL) { gcc_assert (BB_HEAD (e->dest) == label_rtx (lp->post_landing_pad)); redirect_edge_succ (e, BLOCK_FOR_INSN (lp->landing_pad)); e->flags |= (CALL_P (BB_END (bb)) ? EDGE_ABNORMAL | EDGE_ABNORMAL_CALL : EDGE_ABNORMAL); } } } static bool gate_handle_eh (void) { /* Nothing to do if no regions created. */ return cfun->eh->region_tree != NULL; } /* Complete generation of exception handling code. */ static unsigned int rest_of_handle_eh (void) { finish_eh_generation (); cleanup_cfg (CLEANUP_NO_INSN_DEL); return 0; } struct rtl_opt_pass pass_rtl_eh = { { RTL_PASS, "rtl_eh", /* name */ gate_handle_eh, /* gate */ rest_of_handle_eh, /* execute */ NULL, /* sub */ NULL, /* next */ 0, /* static_pass_number */ TV_JUMP, /* tv_id */ 0, /* properties_required */ 0, /* properties_provided */ 0, /* properties_destroyed */ 0, /* todo_flags_start */ 0 /* todo_flags_finish */ } }; /* This section handles removing dead code for flow. */ void remove_eh_landing_pad (eh_landing_pad lp) { eh_landing_pad *pp; for (pp = &lp->region->landing_pads; *pp != lp; pp = &(*pp)->next_lp) continue; *pp = lp->next_lp; if (lp->post_landing_pad) EH_LANDING_PAD_NR (lp->post_landing_pad) = 0; VEC_replace (eh_landing_pad, cfun->eh->lp_array, lp->index, NULL); } /* Splice REGION from the region tree. */ void remove_eh_handler (eh_region region) { eh_region *pp, *pp_start, p, outer; eh_landing_pad lp; for (lp = region->landing_pads; lp ; lp = lp->next_lp) { if (lp->post_landing_pad) EH_LANDING_PAD_NR (lp->post_landing_pad) = 0; VEC_replace (eh_landing_pad, cfun->eh->lp_array, lp->index, NULL); } outer = region->outer; if (outer) pp_start = &outer->inner; else pp_start = &cfun->eh->region_tree; for (pp = pp_start, p = *pp; p != region; pp = &p->next_peer, p = *pp) continue; if (region->inner) { *pp = p = region->inner; do { p->outer = outer; pp = &p->next_peer; p = *pp; } while (p); } *pp = region->next_peer; VEC_replace (eh_region, cfun->eh->region_array, region->index, NULL); } /* Invokes CALLBACK for every exception handler landing pad label. Only used by reload hackery; should not be used by new code. */ void for_each_eh_label (void (*callback) (rtx)) { eh_landing_pad lp; int i; for (i = 1; VEC_iterate (eh_landing_pad, cfun->eh->lp_array, i, lp); ++i) { if (lp) { rtx lab = lp->landing_pad; if (lab && LABEL_P (lab)) (*callback) (lab); } } } /* Create the REG_EH_REGION note for INSN, given its ECF_FLAGS for a call insn. At the gimple level, we use LP_NR > 0 : The statement transfers to landing pad LP_NR = 0 : The statement is outside any EH region < 0 : The statement is within MUST_NOT_THROW region -LP_NR. At the rtl level, we use LP_NR > 0 : The insn transfers to landing pad LP_NR = 0 : The insn cannot throw < 0 : The insn is within MUST_NOT_THROW region -LP_NR = INT_MIN : The insn cannot throw or execute a nonlocal-goto. missing note: The insn is outside any EH region. ??? This difference probably ought to be avoided. We could stand to record nothrow for arbitrary gimple statements, and so avoid some moderately complex lookups in stmt_could_throw_p. Perhaps NOTHROW should be mapped on both sides to INT_MIN. Perhaps the no-nonlocal-goto property should be recorded elsewhere as a bit on the call_insn directly. Perhaps we should make more use of attaching the trees to call_insns (reachable via symbol_ref in direct call cases) and just pull the data out of the trees. */ void make_reg_eh_region_note (rtx insn, int ecf_flags, int lp_nr) { rtx value; if (ecf_flags & ECF_NOTHROW) value = const0_rtx; else if (lp_nr != 0) value = GEN_INT (lp_nr); else return; add_reg_note (insn, REG_EH_REGION, value); } /* Create a REG_EH_REGION note for a CALL_INSN that cannot throw nor perform a non-local goto. Replace the region note if it already exists. */ void make_reg_eh_region_note_nothrow_nononlocal (rtx insn) { rtx note = find_reg_note (insn, REG_EH_REGION, NULL_RTX); rtx intmin = GEN_INT (INT_MIN); if (note != 0) XEXP (note, 0) = intmin; else add_reg_note (insn, REG_EH_REGION, intmin); } /* Return true if INSN could throw, assuming no REG_EH_REGION note to the contrary. */ bool insn_could_throw_p (const_rtx insn) { if (!flag_exceptions) return false; if (CALL_P (insn)) return true; if (INSN_P (insn) && cfun->can_throw_non_call_exceptions) return may_trap_p (PATTERN (insn)); return false; } /* Copy an REG_EH_REGION note to each insn that might throw beginning at FIRST and ending at LAST. NOTE_OR_INSN is either the source insn to look for a note, or the note itself. */ void copy_reg_eh_region_note_forward (rtx note_or_insn, rtx first, rtx last) { rtx insn, note = note_or_insn; if (INSN_P (note_or_insn)) { note = find_reg_note (note_or_insn, REG_EH_REGION, NULL_RTX); if (note == NULL) return; } note = XEXP (note, 0); for (insn = first; insn != last ; insn = NEXT_INSN (insn)) if (!find_reg_note (insn, REG_EH_REGION, NULL_RTX) && insn_could_throw_p (insn)) add_reg_note (insn, REG_EH_REGION, note); } /* Likewise, but iterate backward. */ void copy_reg_eh_region_note_backward (rtx note_or_insn, rtx last, rtx first) { rtx insn, note = note_or_insn; if (INSN_P (note_or_insn)) { note = find_reg_note (note_or_insn, REG_EH_REGION, NULL_RTX); if (note == NULL) return; } note = XEXP (note, 0); for (insn = last; insn != first; insn = PREV_INSN (insn)) if (insn_could_throw_p (insn)) add_reg_note (insn, REG_EH_REGION, note); } /* Extract all EH information from INSN. Return true if the insn was marked NOTHROW. */ static bool get_eh_region_and_lp_from_rtx (const_rtx insn, eh_region *pr, eh_landing_pad *plp) { eh_landing_pad lp = NULL; eh_region r = NULL; bool ret = false; rtx note; int lp_nr; if (! INSN_P (insn)) goto egress; if (NONJUMP_INSN_P (insn) && GET_CODE (PATTERN (insn)) == SEQUENCE) insn = XVECEXP (PATTERN (insn), 0, 0); note = find_reg_note (insn, REG_EH_REGION, NULL_RTX); if (!note) { ret = !insn_could_throw_p (insn); goto egress; } lp_nr = INTVAL (XEXP (note, 0)); if (lp_nr == 0 || lp_nr == INT_MIN) { ret = true; goto egress; } if (lp_nr < 0) r = VEC_index (eh_region, cfun->eh->region_array, -lp_nr); else { lp = VEC_index (eh_landing_pad, cfun->eh->lp_array, lp_nr); r = lp->region; } egress: *plp = lp; *pr = r; return ret; } /* Return the landing pad to which INSN may go, or NULL if it does not have a reachable landing pad within this function. */ eh_landing_pad get_eh_landing_pad_from_rtx (const_rtx insn) { eh_landing_pad lp; eh_region r; get_eh_region_and_lp_from_rtx (insn, &r, &lp); return lp; } /* Return the region to which INSN may go, or NULL if it does not have a reachable region within this function. */ eh_region get_eh_region_from_rtx (const_rtx insn) { eh_landing_pad lp; eh_region r; get_eh_region_and_lp_from_rtx (insn, &r, &lp); return r; } /* Return true if INSN throws and is caught by something in this function. */ bool can_throw_internal (const_rtx insn) { return get_eh_landing_pad_from_rtx (insn) != NULL; } /* Return true if INSN throws and escapes from the current function. */ bool can_throw_external (const_rtx insn) { eh_landing_pad lp; eh_region r; bool nothrow; if (! INSN_P (insn)) return false; if (NONJUMP_INSN_P (insn) && GET_CODE (PATTERN (insn)) == SEQUENCE) { rtx seq = PATTERN (insn); int i, n = XVECLEN (seq, 0); for (i = 0; i < n; i++) if (can_throw_external (XVECEXP (seq, 0, i))) return true; return false; } nothrow = get_eh_region_and_lp_from_rtx (insn, &r, &lp); /* If we can't throw, we obviously can't throw external. */ if (nothrow) return false; /* If we have an internal landing pad, then we're not external. */ if (lp != NULL) return false; /* If we're not within an EH region, then we are external. */ if (r == NULL) return true; /* The only thing that ought to be left is MUST_NOT_THROW regions, which don't always have landing pads. */ gcc_assert (r->type == ERT_MUST_NOT_THROW); return false; } /* Return true if INSN cannot throw at all. */ bool insn_nothrow_p (const_rtx insn) { eh_landing_pad lp; eh_region r; if (! INSN_P (insn)) return true; if (NONJUMP_INSN_P (insn) && GET_CODE (PATTERN (insn)) == SEQUENCE) { rtx seq = PATTERN (insn); int i, n = XVECLEN (seq, 0); for (i = 0; i < n; i++) if (!insn_nothrow_p (XVECEXP (seq, 0, i))) return false; return true; } return get_eh_region_and_lp_from_rtx (insn, &r, &lp); } /* Return true if INSN can perform a non-local goto. */ /* ??? This test is here in this file because it (ab)uses REG_EH_REGION. */ bool can_nonlocal_goto (const_rtx insn) { if (nonlocal_goto_handler_labels && CALL_P (insn)) { rtx note = find_reg_note (insn, REG_EH_REGION, NULL_RTX); if (!note || INTVAL (XEXP (note, 0)) != INT_MIN) return true; } return false; } /* Set TREE_NOTHROW and crtl->all_throwers_are_sibcalls. */ static unsigned int set_nothrow_function_flags (void) { rtx insn; crtl->nothrow = 1; /* Assume crtl->all_throwers_are_sibcalls until we encounter something that can throw an exception. We specifically exempt CALL_INSNs that are SIBLING_CALL_P, as these are really jumps, and can't throw. Most CALL_INSNs are not SIBLING_CALL_P, so this is optimistic. */ crtl->all_throwers_are_sibcalls = 1; /* If we don't know that this implementation of the function will actually be used, then we must not set TREE_NOTHROW, since callers must not assume that this function does not throw. */ if (TREE_NOTHROW (current_function_decl)) return 0; if (! flag_exceptions) return 0; for (insn = get_insns (); insn; insn = NEXT_INSN (insn)) if (can_throw_external (insn)) { crtl->nothrow = 0; if (!CALL_P (insn) || !SIBLING_CALL_P (insn)) { crtl->all_throwers_are_sibcalls = 0; return 0; } } for (insn = crtl->epilogue_delay_list; insn; insn = XEXP (insn, 1)) if (can_throw_external (insn)) { crtl->nothrow = 0; if (!CALL_P (insn) || !SIBLING_CALL_P (insn)) { crtl->all_throwers_are_sibcalls = 0; return 0; } } if (crtl->nothrow && (cgraph_function_body_availability (cgraph_get_node (current_function_decl)) >= AVAIL_AVAILABLE)) { struct cgraph_node *node = cgraph_get_node (current_function_decl); struct cgraph_edge *e; for (e = node->callers; e; e = e->next_caller) e->can_throw_external = false; cgraph_set_nothrow_flag (node, true); if (dump_file) fprintf (dump_file, "Marking function nothrow: %s\n\n", current_function_name ()); } return 0; } struct rtl_opt_pass pass_set_nothrow_function_flags = { { RTL_PASS, "nothrow", /* name */ NULL, /* gate */ set_nothrow_function_flags, /* execute */ NULL, /* sub */ NULL, /* next */ 0, /* static_pass_number */ TV_NONE, /* tv_id */ 0, /* properties_required */ 0, /* properties_provided */ 0, /* properties_destroyed */ 0, /* todo_flags_start */ 0 /* todo_flags_finish */ } }; /* Various hooks for unwind library. */ /* Expand the EH support builtin functions: __builtin_eh_pointer and __builtin_eh_filter. */ static eh_region expand_builtin_eh_common (tree region_nr_t) { HOST_WIDE_INT region_nr; eh_region region; gcc_assert (host_integerp (region_nr_t, 0)); region_nr = tree_low_cst (region_nr_t, 0); region = VEC_index (eh_region, cfun->eh->region_array, region_nr); /* ??? We shouldn't have been able to delete a eh region without deleting all the code that depended on it. */ gcc_assert (region != NULL); return region; } /* Expand to the exc_ptr value from the given eh region. */ rtx expand_builtin_eh_pointer (tree exp) { eh_region region = expand_builtin_eh_common (CALL_EXPR_ARG (exp, 0)); if (region->exc_ptr_reg == NULL) region->exc_ptr_reg = gen_reg_rtx (ptr_mode); return region->exc_ptr_reg; } /* Expand to the filter value from the given eh region. */ rtx expand_builtin_eh_filter (tree exp) { eh_region region = expand_builtin_eh_common (CALL_EXPR_ARG (exp, 0)); if (region->filter_reg == NULL) region->filter_reg = gen_reg_rtx (targetm.eh_return_filter_mode ()); return region->filter_reg; } /* Copy the exc_ptr and filter values from one landing pad's registers to another. This is used to inline the resx statement. */ rtx expand_builtin_eh_copy_values (tree exp) { eh_region dst = expand_builtin_eh_common (CALL_EXPR_ARG (exp, 0)); eh_region src = expand_builtin_eh_common (CALL_EXPR_ARG (exp, 1)); enum machine_mode fmode = targetm.eh_return_filter_mode (); if (dst->exc_ptr_reg == NULL) dst->exc_ptr_reg = gen_reg_rtx (ptr_mode); if (src->exc_ptr_reg == NULL) src->exc_ptr_reg = gen_reg_rtx (ptr_mode); if (dst->filter_reg == NULL) dst->filter_reg = gen_reg_rtx (fmode); if (src->filter_reg == NULL) src->filter_reg = gen_reg_rtx (fmode); emit_move_insn (dst->exc_ptr_reg, src->exc_ptr_reg); emit_move_insn (dst->filter_reg, src->filter_reg); return const0_rtx; } /* Do any necessary initialization to access arbitrary stack frames. On the SPARC, this means flushing the register windows. */ void expand_builtin_unwind_init (void) { /* Set this so all the registers get saved in our frame; we need to be able to copy the saved values for any registers from frames we unwind. */ crtl->saves_all_registers = 1; #ifdef SETUP_FRAME_ADDRESSES SETUP_FRAME_ADDRESSES (); #endif } /* Map a non-negative number to an eh return data register number; expands to -1 if no return data register is associated with the input number. At least the inputs 0 and 1 must be mapped; the target may provide more. */ rtx expand_builtin_eh_return_data_regno (tree exp) { tree which = CALL_EXPR_ARG (exp, 0); unsigned HOST_WIDE_INT iwhich; if (TREE_CODE (which) != INTEGER_CST) { error ("argument of %<__builtin_eh_return_regno%> must be constant"); return constm1_rtx; } iwhich = tree_low_cst (which, 1); iwhich = EH_RETURN_DATA_REGNO (iwhich); if (iwhich == INVALID_REGNUM) return constm1_rtx; #ifdef DWARF_FRAME_REGNUM iwhich = DWARF_FRAME_REGNUM (iwhich); #else iwhich = DBX_REGISTER_NUMBER (iwhich); #endif return GEN_INT (iwhich); } /* Given a value extracted from the return address register or stack slot, return the actual address encoded in that value. */ rtx expand_builtin_extract_return_addr (tree addr_tree) { rtx addr = expand_expr (addr_tree, NULL_RTX, Pmode, EXPAND_NORMAL); if (GET_MODE (addr) != Pmode && GET_MODE (addr) != VOIDmode) { #ifdef POINTERS_EXTEND_UNSIGNED addr = convert_memory_address (Pmode, addr); #else addr = convert_to_mode (Pmode, addr, 0); #endif } /* First mask out any unwanted bits. */ #ifdef MASK_RETURN_ADDR expand_and (Pmode, addr, MASK_RETURN_ADDR, addr); #endif /* Then adjust to find the real return address. */ #if defined (RETURN_ADDR_OFFSET) addr = plus_constant (addr, RETURN_ADDR_OFFSET); #endif return addr; } /* Given an actual address in addr_tree, do any necessary encoding and return the value to be stored in the return address register or stack slot so the epilogue will return to that address. */ rtx expand_builtin_frob_return_addr (tree addr_tree) { rtx addr = expand_expr (addr_tree, NULL_RTX, ptr_mode, EXPAND_NORMAL); addr = convert_memory_address (Pmode, addr); #ifdef RETURN_ADDR_OFFSET addr = force_reg (Pmode, addr); addr = plus_constant (addr, -RETURN_ADDR_OFFSET); #endif return addr; } /* Set up the epilogue with the magic bits we'll need to return to the exception handler. */ void expand_builtin_eh_return (tree stackadj_tree ATTRIBUTE_UNUSED, tree handler_tree) { rtx tmp; #ifdef EH_RETURN_STACKADJ_RTX tmp = expand_expr (stackadj_tree, crtl->eh.ehr_stackadj, VOIDmode, EXPAND_NORMAL); tmp = convert_memory_address (Pmode, tmp); if (!crtl->eh.ehr_stackadj) crtl->eh.ehr_stackadj = copy_to_reg (tmp); else if (tmp != crtl->eh.ehr_stackadj) emit_move_insn (crtl->eh.ehr_stackadj, tmp); #endif tmp = expand_expr (handler_tree, crtl->eh.ehr_handler, VOIDmode, EXPAND_NORMAL); tmp = convert_memory_address (Pmode, tmp); if (!crtl->eh.ehr_handler) crtl->eh.ehr_handler = copy_to_reg (tmp); else if (tmp != crtl->eh.ehr_handler) emit_move_insn (crtl->eh.ehr_handler, tmp); if (!crtl->eh.ehr_label) crtl->eh.ehr_label = gen_label_rtx (); emit_jump (crtl->eh.ehr_label); } /* Expand __builtin_eh_return. This exit path from the function loads up the eh return data registers, adjusts the stack, and branches to a given PC other than the normal return address. */ void expand_eh_return (void) { rtx around_label; if (! crtl->eh.ehr_label) return; crtl->calls_eh_return = 1; #ifdef EH_RETURN_STACKADJ_RTX emit_move_insn (EH_RETURN_STACKADJ_RTX, const0_rtx); #endif around_label = gen_label_rtx (); emit_jump (around_label); emit_label (crtl->eh.ehr_label); clobber_return_register (); #ifdef EH_RETURN_STACKADJ_RTX emit_move_insn (EH_RETURN_STACKADJ_RTX, crtl->eh.ehr_stackadj); #endif #ifdef HAVE_eh_return if (HAVE_eh_return) emit_insn (gen_eh_return (crtl->eh.ehr_handler)); else #endif { #ifdef EH_RETURN_HANDLER_RTX emit_move_insn (EH_RETURN_HANDLER_RTX, crtl->eh.ehr_handler); #else error ("__builtin_eh_return not supported on this target"); #endif } emit_label (around_label); } /* Convert a ptr_mode address ADDR_TREE to a Pmode address controlled by POINTERS_EXTEND_UNSIGNED and return it. */ rtx expand_builtin_extend_pointer (tree addr_tree) { rtx addr = expand_expr (addr_tree, NULL_RTX, ptr_mode, EXPAND_NORMAL); int extend; #ifdef POINTERS_EXTEND_UNSIGNED extend = POINTERS_EXTEND_UNSIGNED; #else /* The previous EH code did an unsigned extend by default, so we do this also for consistency. */ extend = 1; #endif return convert_modes (targetm.unwind_word_mode (), ptr_mode, addr, extend); } /* In the following functions, we represent entries in the action table as 1-based indices. Special cases are: 0: null action record, non-null landing pad; implies cleanups -1: null action record, null landing pad; implies no action -2: no call-site entry; implies must_not_throw -3: we have yet to process outer regions Further, no special cases apply to the "next" field of the record. For next, 0 means end of list. */ struct action_record { int offset; int filter; int next; }; static int action_record_eq (const void *pentry, const void *pdata) { const struct action_record *entry = (const struct action_record *) pentry; const struct action_record *data = (const struct action_record *) pdata; return entry->filter == data->filter && entry->next == data->next; } static hashval_t action_record_hash (const void *pentry) { const struct action_record *entry = (const struct action_record *) pentry; return entry->next * 1009 + entry->filter; } static int add_action_record (htab_t ar_hash, int filter, int next) { struct action_record **slot, *new_ar, tmp; tmp.filter = filter; tmp.next = next; slot = (struct action_record **) htab_find_slot (ar_hash, &tmp, INSERT); if ((new_ar = *slot) == NULL) { new_ar = XNEW (struct action_record); new_ar->offset = VEC_length (uchar, crtl->eh.action_record_data) + 1; new_ar->filter = filter; new_ar->next = next; *slot = new_ar; /* The filter value goes in untouched. The link to the next record is a "self-relative" byte offset, or zero to indicate that there is no next record. So convert the absolute 1 based indices we've been carrying around into a displacement. */ push_sleb128 (&crtl->eh.action_record_data, filter); if (next) next -= VEC_length (uchar, crtl->eh.action_record_data) + 1; push_sleb128 (&crtl->eh.action_record_data, next); } return new_ar->offset; } static int collect_one_action_chain (htab_t ar_hash, eh_region region) { int next; /* If we've reached the top of the region chain, then we have no actions, and require no landing pad. */ if (region == NULL) return -1; switch (region->type) { case ERT_CLEANUP: { eh_region r; /* A cleanup adds a zero filter to the beginning of the chain, but there are special cases to look out for. If there are *only* cleanups along a path, then it compresses to a zero action. Further, if there are multiple cleanups along a path, we only need to represent one of them, as that is enough to trigger entry to the landing pad at runtime. */ next = collect_one_action_chain (ar_hash, region->outer); if (next <= 0) return 0; for (r = region->outer; r ; r = r->outer) if (r->type == ERT_CLEANUP) return next; return add_action_record (ar_hash, 0, next); } case ERT_TRY: { eh_catch c; /* Process the associated catch regions in reverse order. If there's a catch-all handler, then we don't need to search outer regions. Use a magic -3 value to record that we haven't done the outer search. */ next = -3; for (c = region->u.eh_try.last_catch; c ; c = c->prev_catch) { if (c->type_list == NULL) { /* Retrieve the filter from the head of the filter list where we have stored it (see assign_filter_values). */ int filter = TREE_INT_CST_LOW (TREE_VALUE (c->filter_list)); next = add_action_record (ar_hash, filter, 0); } else { /* Once the outer search is done, trigger an action record for each filter we have. */ tree flt_node; if (next == -3) { next = collect_one_action_chain (ar_hash, region->outer); /* If there is no next action, terminate the chain. */ if (next == -1) next = 0; /* If all outer actions are cleanups or must_not_throw, we'll have no action record for it, since we had wanted to encode these states in the call-site record directly. Add a cleanup action to the chain to catch these. */ else if (next <= 0) next = add_action_record (ar_hash, 0, 0); } flt_node = c->filter_list; for (; flt_node; flt_node = TREE_CHAIN (flt_node)) { int filter = TREE_INT_CST_LOW (TREE_VALUE (flt_node)); next = add_action_record (ar_hash, filter, next); } } } return next; } case ERT_ALLOWED_EXCEPTIONS: /* An exception specification adds its filter to the beginning of the chain. */ next = collect_one_action_chain (ar_hash, region->outer); /* If there is no next action, terminate the chain. */ if (next == -1) next = 0; /* If all outer actions are cleanups or must_not_throw, we'll have no action record for it, since we had wanted to encode these states in the call-site record directly. Add a cleanup action to the chain to catch these. */ else if (next <= 0) next = add_action_record (ar_hash, 0, 0); return add_action_record (ar_hash, region->u.allowed.filter, next); case ERT_MUST_NOT_THROW: /* A must-not-throw region with no inner handlers or cleanups requires no call-site entry. Note that this differs from the no handler or cleanup case in that we do require an lsda to be generated. Return a magic -2 value to record this. */ return -2; } gcc_unreachable (); } static int add_call_site (rtx landing_pad, int action, int section) { call_site_record record; record = ggc_alloc_call_site_record_d (); record->landing_pad = landing_pad; record->action = action; VEC_safe_push (call_site_record, gc, crtl->eh.call_site_record[section], record); return call_site_base + VEC_length (call_site_record, crtl->eh.call_site_record[section]) - 1; } /* Turn REG_EH_REGION notes back into NOTE_INSN_EH_REGION notes. The new note numbers will not refer to region numbers, but instead to call site entries. */ static unsigned int convert_to_eh_region_ranges (void) { rtx insn, iter, note; htab_t ar_hash; int last_action = -3; rtx last_action_insn = NULL_RTX; rtx last_landing_pad = NULL_RTX; rtx first_no_action_insn = NULL_RTX; int call_site = 0; int cur_sec = 0; rtx section_switch_note = NULL_RTX; rtx first_no_action_insn_before_switch = NULL_RTX; rtx last_no_action_insn_before_switch = NULL_RTX; int saved_call_site_base = call_site_base; crtl->eh.action_record_data = VEC_alloc (uchar, gc, 64); ar_hash = htab_create (31, action_record_hash, action_record_eq, free); for (iter = get_insns (); iter ; iter = NEXT_INSN (iter)) if (INSN_P (iter)) { eh_landing_pad lp; eh_region region; bool nothrow; int this_action; rtx this_landing_pad; insn = iter; if (NONJUMP_INSN_P (insn) && GET_CODE (PATTERN (insn)) == SEQUENCE) insn = XVECEXP (PATTERN (insn), 0, 0); nothrow = get_eh_region_and_lp_from_rtx (insn, ®ion, &lp); if (nothrow) continue; if (region) this_action = collect_one_action_chain (ar_hash, region); else this_action = -1; /* Existence of catch handlers, or must-not-throw regions implies that an lsda is needed (even if empty). */ if (this_action != -1) crtl->uses_eh_lsda = 1; /* Delay creation of region notes for no-action regions until we're sure that an lsda will be required. */ else if (last_action == -3) { first_no_action_insn = iter; last_action = -1; } if (this_action >= 0) this_landing_pad = lp->landing_pad; else this_landing_pad = NULL_RTX; /* Differing actions or landing pads implies a change in call-site info, which implies some EH_REGION note should be emitted. */ if (last_action != this_action || last_landing_pad != this_landing_pad) { /* If there is a queued no-action region in the other section with hot/cold partitioning, emit it now. */ if (first_no_action_insn_before_switch) { gcc_assert (this_action != -1 && last_action == (first_no_action_insn ? -1 : -3)); call_site = add_call_site (NULL_RTX, 0, 0); note = emit_note_before (NOTE_INSN_EH_REGION_BEG, first_no_action_insn_before_switch); NOTE_EH_HANDLER (note) = call_site; note = emit_note_after (NOTE_INSN_EH_REGION_END, last_no_action_insn_before_switch); NOTE_EH_HANDLER (note) = call_site; gcc_assert (last_action != -3 || (last_action_insn == last_no_action_insn_before_switch)); first_no_action_insn_before_switch = NULL_RTX; last_no_action_insn_before_switch = NULL_RTX; call_site_base++; } /* If we'd not seen a previous action (-3) or the previous action was must-not-throw (-2), then we do not need an end note. */ if (last_action >= -1) { /* If we delayed the creation of the begin, do it now. */ if (first_no_action_insn) { call_site = add_call_site (NULL_RTX, 0, cur_sec); note = emit_note_before (NOTE_INSN_EH_REGION_BEG, first_no_action_insn); NOTE_EH_HANDLER (note) = call_site; first_no_action_insn = NULL_RTX; } note = emit_note_after (NOTE_INSN_EH_REGION_END, last_action_insn); NOTE_EH_HANDLER (note) = call_site; } /* If the new action is must-not-throw, then no region notes are created. */ if (this_action >= -1) { call_site = add_call_site (this_landing_pad, this_action < 0 ? 0 : this_action, cur_sec); note = emit_note_before (NOTE_INSN_EH_REGION_BEG, iter); NOTE_EH_HANDLER (note) = call_site; } last_action = this_action; last_landing_pad = this_landing_pad; } last_action_insn = iter; } else if (NOTE_P (iter) && NOTE_KIND (iter) == NOTE_INSN_SWITCH_TEXT_SECTIONS) { gcc_assert (section_switch_note == NULL_RTX); gcc_assert (flag_reorder_blocks_and_partition); section_switch_note = iter; if (first_no_action_insn) { first_no_action_insn_before_switch = first_no_action_insn; last_no_action_insn_before_switch = last_action_insn; first_no_action_insn = NULL_RTX; gcc_assert (last_action == -1); last_action = -3; } /* Force closing of current EH region before section switch and opening a new one afterwards. */ else if (last_action != -3) last_landing_pad = pc_rtx; call_site_base += VEC_length (call_site_record, crtl->eh.call_site_record[cur_sec]); cur_sec++; gcc_assert (crtl->eh.call_site_record[cur_sec] == NULL); crtl->eh.call_site_record[cur_sec] = VEC_alloc (call_site_record, gc, 10); } if (last_action >= -1 && ! first_no_action_insn) { note = emit_note_after (NOTE_INSN_EH_REGION_END, last_action_insn); NOTE_EH_HANDLER (note) = call_site; } call_site_base = saved_call_site_base; htab_delete (ar_hash); return 0; } static bool gate_convert_to_eh_region_ranges (void) { /* Nothing to do for SJLJ exceptions or if no regions created. */ if (cfun->eh->region_tree == NULL) return false; if (targetm_common.except_unwind_info (&global_options) == UI_SJLJ) return false; return true; } struct rtl_opt_pass pass_convert_to_eh_region_ranges = { { RTL_PASS, "eh_ranges", /* name */ gate_convert_to_eh_region_ranges, /* gate */ convert_to_eh_region_ranges, /* execute */ NULL, /* sub */ NULL, /* next */ 0, /* static_pass_number */ TV_NONE, /* tv_id */ 0, /* properties_required */ 0, /* properties_provided */ 0, /* properties_destroyed */ 0, /* todo_flags_start */ 0 /* todo_flags_finish */ } }; static void push_uleb128 (VEC (uchar, gc) **data_area, unsigned int value) { do { unsigned char byte = value & 0x7f; value >>= 7; if (value) byte |= 0x80; VEC_safe_push (uchar, gc, *data_area, byte); } while (value); } static void push_sleb128 (VEC (uchar, gc) **data_area, int value) { unsigned char byte; int more; do { byte = value & 0x7f; value >>= 7; more = ! ((value == 0 && (byte & 0x40) == 0) || (value == -1 && (byte & 0x40) != 0)); if (more) byte |= 0x80; VEC_safe_push (uchar, gc, *data_area, byte); } while (more); } #ifndef HAVE_AS_LEB128 static int dw2_size_of_call_site_table (int section) { int n = VEC_length (call_site_record, crtl->eh.call_site_record[section]); int size = n * (4 + 4 + 4); int i; for (i = 0; i < n; ++i) { struct call_site_record_d *cs = VEC_index (call_site_record, crtl->eh.call_site_record[section], i); size += size_of_uleb128 (cs->action); } return size; } static int sjlj_size_of_call_site_table (void) { int n = VEC_length (call_site_record, crtl->eh.call_site_record[0]); int size = 0; int i; for (i = 0; i < n; ++i) { struct call_site_record_d *cs = VEC_index (call_site_record, crtl->eh.call_site_record[0], i); size += size_of_uleb128 (INTVAL (cs->landing_pad)); size += size_of_uleb128 (cs->action); } return size; } #endif static void dw2_output_call_site_table (int cs_format, int section) { int n = VEC_length (call_site_record, crtl->eh.call_site_record[section]); int i; const char *begin; if (section == 0) begin = current_function_func_begin_label; else if (first_function_block_is_cold) begin = crtl->subsections.hot_section_label; else begin = crtl->subsections.cold_section_label; for (i = 0; i < n; ++i) { struct call_site_record_d *cs = VEC_index (call_site_record, crtl->eh.call_site_record[section], i); char reg_start_lab[32]; char reg_end_lab[32]; char landing_pad_lab[32]; ASM_GENERATE_INTERNAL_LABEL (reg_start_lab, "LEHB", call_site_base + i); ASM_GENERATE_INTERNAL_LABEL (reg_end_lab, "LEHE", call_site_base + i); if (cs->landing_pad) ASM_GENERATE_INTERNAL_LABEL (landing_pad_lab, "L", CODE_LABEL_NUMBER (cs->landing_pad)); /* ??? Perhaps use insn length scaling if the assembler supports generic arithmetic. */ /* ??? Perhaps use attr_length to choose data1 or data2 instead of data4 if the function is small enough. */ if (cs_format == DW_EH_PE_uleb128) { dw2_asm_output_delta_uleb128 (reg_start_lab, begin, "region %d start", i); dw2_asm_output_delta_uleb128 (reg_end_lab, reg_start_lab, "length"); if (cs->landing_pad) dw2_asm_output_delta_uleb128 (landing_pad_lab, begin, "landing pad"); else dw2_asm_output_data_uleb128 (0, "landing pad"); } else { dw2_asm_output_delta (4, reg_start_lab, begin, "region %d start", i); dw2_asm_output_delta (4, reg_end_lab, reg_start_lab, "length"); if (cs->landing_pad) dw2_asm_output_delta (4, landing_pad_lab, begin, "landing pad"); else dw2_asm_output_data (4, 0, "landing pad"); } dw2_asm_output_data_uleb128 (cs->action, "action"); } call_site_base += n; } static void sjlj_output_call_site_table (void) { int n = VEC_length (call_site_record, crtl->eh.call_site_record[0]); int i; for (i = 0; i < n; ++i) { struct call_site_record_d *cs = VEC_index (call_site_record, crtl->eh.call_site_record[0], i); dw2_asm_output_data_uleb128 (INTVAL (cs->landing_pad), "region %d landing pad", i); dw2_asm_output_data_uleb128 (cs->action, "action"); } call_site_base += n; } /* Switch to the section that should be used for exception tables. */ static void switch_to_exception_section (const char * ARG_UNUSED (fnname)) { section *s; if (exception_section) s = exception_section; else { /* Compute the section and cache it into exception_section, unless it depends on the function name. */ if (targetm_common.have_named_sections) { int flags; if (EH_TABLES_CAN_BE_READ_ONLY) { int tt_format = ASM_PREFERRED_EH_DATA_FORMAT (/*code=*/0, /*global=*/1); flags = ((! flag_pic || ((tt_format & 0x70) != DW_EH_PE_absptr && (tt_format & 0x70) != DW_EH_PE_aligned)) ? 0 : SECTION_WRITE); } else flags = SECTION_WRITE; #ifdef HAVE_LD_EH_GC_SECTIONS if (flag_function_sections) { char *section_name = XNEWVEC (char, strlen (fnname) + 32); sprintf (section_name, ".gcc_except_table.%s", fnname); s = get_section (section_name, flags, NULL); free (section_name); } else #endif exception_section = s = get_section (".gcc_except_table", flags, NULL); } else exception_section = s = flag_pic ? data_section : readonly_data_section; } switch_to_section (s); } /* Output a reference from an exception table to the type_info object TYPE. TT_FORMAT and TT_FORMAT_SIZE describe the DWARF encoding method used for the value. */ static void output_ttype (tree type, int tt_format, int tt_format_size) { rtx value; bool is_public = true; if (type == NULL_TREE) value = const0_rtx; else { struct varpool_node *node; /* FIXME lto. pass_ipa_free_lang_data changes all types to runtime types so TYPE should already be a runtime type reference. When pass_ipa_free_lang data is made a default pass, we can then remove the call to lookup_type_for_runtime below. */ if (TYPE_P (type)) type = lookup_type_for_runtime (type); value = expand_expr (type, NULL_RTX, VOIDmode, EXPAND_INITIALIZER); /* Let cgraph know that the rtti decl is used. Not all of the paths below go through assemble_integer, which would take care of this for us. */ STRIP_NOPS (type); if (TREE_CODE (type) == ADDR_EXPR) { type = TREE_OPERAND (type, 0); if (TREE_CODE (type) == VAR_DECL) { node = varpool_node (type); if (node) varpool_mark_needed_node (node); is_public = TREE_PUBLIC (type); } } else gcc_assert (TREE_CODE (type) == INTEGER_CST); } /* Allow the target to override the type table entry format. */ if (targetm.asm_out.ttype (value)) return; if (tt_format == DW_EH_PE_absptr || tt_format == DW_EH_PE_aligned) assemble_integer (value, tt_format_size, tt_format_size * BITS_PER_UNIT, 1); else dw2_asm_output_encoded_addr_rtx (tt_format, value, is_public, NULL); } static void output_one_function_exception_table (int section) { int tt_format, cs_format, lp_format, i; #ifdef HAVE_AS_LEB128 char ttype_label[32]; char cs_after_size_label[32]; char cs_end_label[32]; #else int call_site_len; #endif int have_tt_data; int tt_format_size = 0; have_tt_data = (VEC_length (tree, cfun->eh->ttype_data) || (targetm.arm_eabi_unwinder ? VEC_length (tree, cfun->eh->ehspec_data.arm_eabi) : VEC_length (uchar, cfun->eh->ehspec_data.other))); /* Indicate the format of the @TType entries. */ if (! have_tt_data) tt_format = DW_EH_PE_omit; else { tt_format = ASM_PREFERRED_EH_DATA_FORMAT (/*code=*/0, /*global=*/1); #ifdef HAVE_AS_LEB128 ASM_GENERATE_INTERNAL_LABEL (ttype_label, section ? "LLSDATTC" : "LLSDATT", current_function_funcdef_no); #endif tt_format_size = size_of_encoded_value (tt_format); assemble_align (tt_format_size * BITS_PER_UNIT); } targetm.asm_out.internal_label (asm_out_file, section ? "LLSDAC" : "LLSDA", current_function_funcdef_no); /* The LSDA header. */ /* Indicate the format of the landing pad start pointer. An omitted field implies @LPStart == @Start. */ /* Currently we always put @LPStart == @Start. This field would be most useful in moving the landing pads completely out of line to another section, but it could also be used to minimize the size of uleb128 landing pad offsets. */ lp_format = DW_EH_PE_omit; dw2_asm_output_data (1, lp_format, "@LPStart format (%s)", eh_data_format_name (lp_format)); /* @LPStart pointer would go here. */ dw2_asm_output_data (1, tt_format, "@TType format (%s)", eh_data_format_name (tt_format)); #ifndef HAVE_AS_LEB128 if (targetm_common.except_unwind_info (&global_options) == UI_SJLJ) call_site_len = sjlj_size_of_call_site_table (); else call_site_len = dw2_size_of_call_site_table (section); #endif /* A pc-relative 4-byte displacement to the @TType data. */ if (have_tt_data) { #ifdef HAVE_AS_LEB128 char ttype_after_disp_label[32]; ASM_GENERATE_INTERNAL_LABEL (ttype_after_disp_label, section ? "LLSDATTDC" : "LLSDATTD", current_function_funcdef_no); dw2_asm_output_delta_uleb128 (ttype_label, ttype_after_disp_label, "@TType base offset"); ASM_OUTPUT_LABEL (asm_out_file, ttype_after_disp_label); #else /* Ug. Alignment queers things. */ unsigned int before_disp, after_disp, last_disp, disp; before_disp = 1 + 1; after_disp = (1 + size_of_uleb128 (call_site_len) + call_site_len + VEC_length (uchar, crtl->eh.action_record_data) + (VEC_length (tree, cfun->eh->ttype_data) * tt_format_size)); disp = after_disp; do { unsigned int disp_size, pad; last_disp = disp; disp_size = size_of_uleb128 (disp); pad = before_disp + disp_size + after_disp; if (pad % tt_format_size) pad = tt_format_size - (pad % tt_format_size); else pad = 0; disp = after_disp + pad; } while (disp != last_disp); dw2_asm_output_data_uleb128 (disp, "@TType base offset"); #endif } /* Indicate the format of the call-site offsets. */ #ifdef HAVE_AS_LEB128 cs_format = DW_EH_PE_uleb128; #else cs_format = DW_EH_PE_udata4; #endif dw2_asm_output_data (1, cs_format, "call-site format (%s)", eh_data_format_name (cs_format)); #ifdef HAVE_AS_LEB128 ASM_GENERATE_INTERNAL_LABEL (cs_after_size_label, section ? "LLSDACSBC" : "LLSDACSB", current_function_funcdef_no); ASM_GENERATE_INTERNAL_LABEL (cs_end_label, section ? "LLSDACSEC" : "LLSDACSE", current_function_funcdef_no); dw2_asm_output_delta_uleb128 (cs_end_label, cs_after_size_label, "Call-site table length"); ASM_OUTPUT_LABEL (asm_out_file, cs_after_size_label); if (targetm_common.except_unwind_info (&global_options) == UI_SJLJ) sjlj_output_call_site_table (); else dw2_output_call_site_table (cs_format, section); ASM_OUTPUT_LABEL (asm_out_file, cs_end_label); #else dw2_asm_output_data_uleb128 (call_site_len, "Call-site table length"); if (targetm_common.except_unwind_info (&global_options) == UI_SJLJ) sjlj_output_call_site_table (); else dw2_output_call_site_table (cs_format, section); #endif /* ??? Decode and interpret the data for flag_debug_asm. */ { uchar uc; FOR_EACH_VEC_ELT (uchar, crtl->eh.action_record_data, i, uc) dw2_asm_output_data (1, uc, i ? NULL : "Action record table"); } if (have_tt_data) assemble_align (tt_format_size * BITS_PER_UNIT); i = VEC_length (tree, cfun->eh->ttype_data); while (i-- > 0) { tree type = VEC_index (tree, cfun->eh->ttype_data, i); output_ttype (type, tt_format, tt_format_size); } #ifdef HAVE_AS_LEB128 if (have_tt_data) ASM_OUTPUT_LABEL (asm_out_file, ttype_label); #endif /* ??? Decode and interpret the data for flag_debug_asm. */ if (targetm.arm_eabi_unwinder) { tree type; for (i = 0; VEC_iterate (tree, cfun->eh->ehspec_data.arm_eabi, i, type); ++i) output_ttype (type, tt_format, tt_format_size); } else { uchar uc; for (i = 0; VEC_iterate (uchar, cfun->eh->ehspec_data.other, i, uc); ++i) dw2_asm_output_data (1, uc, i ? NULL : "Exception specification table"); } } void output_function_exception_table (const char *fnname) { rtx personality = get_personality_function (current_function_decl); /* Not all functions need anything. */ if (! crtl->uses_eh_lsda) return; if (personality) { assemble_external_libcall (personality); if (targetm.asm_out.emit_except_personality) targetm.asm_out.emit_except_personality (personality); } switch_to_exception_section (fnname); /* If the target wants a label to begin the table, emit it here. */ targetm.asm_out.emit_except_table_label (asm_out_file); output_one_function_exception_table (0); if (crtl->eh.call_site_record[1] != NULL) output_one_function_exception_table (1); switch_to_section (current_function_section ()); } void set_eh_throw_stmt_table (struct function *fun, struct htab *table) { fun->eh->throw_stmt_table = table; } htab_t get_eh_throw_stmt_table (struct function *fun) { return fun->eh->throw_stmt_table; } /* Determine if the function needs an EH personality function. */ enum eh_personality_kind function_needs_eh_personality (struct function *fn) { enum eh_personality_kind kind = eh_personality_none; eh_region i; FOR_ALL_EH_REGION_FN (i, fn) { switch (i->type) { case ERT_CLEANUP: /* Can do with any personality including the generic C one. */ kind = eh_personality_any; break; case ERT_TRY: case ERT_ALLOWED_EXCEPTIONS: /* Always needs a EH personality function. The generic C personality doesn't handle these even for empty type lists. */ return eh_personality_lang; case ERT_MUST_NOT_THROW: /* Always needs a EH personality function. The language may specify what abort routine that must be used, e.g. std::terminate. */ return eh_personality_lang; } } return kind; } /* Dump EH information to OUT. */ void dump_eh_tree (FILE * out, struct function *fun) { eh_region i; int depth = 0; static const char *const type_name[] = { "cleanup", "try", "allowed_exceptions", "must_not_throw" }; i = fun->eh->region_tree; if (!i) return; fprintf (out, "Eh tree:\n"); while (1) { fprintf (out, " %*s %i %s", depth * 2, "", i->index, type_name[(int) i->type]); if (i->landing_pads) { eh_landing_pad lp; fprintf (out, " land:"); if (current_ir_type () == IR_GIMPLE) { for (lp = i->landing_pads; lp ; lp = lp->next_lp) { fprintf (out, "{%i,", lp->index); print_generic_expr (out, lp->post_landing_pad, 0); fputc ('}', out); if (lp->next_lp) fputc (',', out); } } else { for (lp = i->landing_pads; lp ; lp = lp->next_lp) { fprintf (out, "{%i,", lp->index); if (lp->landing_pad) fprintf (out, "%i%s,", INSN_UID (lp->landing_pad), NOTE_P (lp->landing_pad) ? "(del)" : ""); else fprintf (out, "(nil),"); if (lp->post_landing_pad) { rtx lab = label_rtx (lp->post_landing_pad); fprintf (out, "%i%s}", INSN_UID (lab), NOTE_P (lab) ? "(del)" : ""); } else fprintf (out, "(nil)}"); if (lp->next_lp) fputc (',', out); } } } switch (i->type) { case ERT_CLEANUP: case ERT_MUST_NOT_THROW: break; case ERT_TRY: { eh_catch c; fprintf (out, " catch:"); for (c = i->u.eh_try.first_catch; c; c = c->next_catch) { fputc ('{', out); if (c->label) { fprintf (out, "lab:"); print_generic_expr (out, c->label, 0); fputc (';', out); } print_generic_expr (out, c->type_list, 0); fputc ('}', out); if (c->next_catch) fputc (',', out); } } break; case ERT_ALLOWED_EXCEPTIONS: fprintf (out, " filter :%i types:", i->u.allowed.filter); print_generic_expr (out, i->u.allowed.type_list, 0); break; } fputc ('\n', out); /* If there are sub-regions, process them. */ if (i->inner) i = i->inner, depth++; /* If there are peers, process them. */ else if (i->next_peer) i = i->next_peer; /* Otherwise, step back up the tree to the next peer. */ else { do { i = i->outer; depth--; if (i == NULL) return; } while (i->next_peer == NULL); i = i->next_peer; } } } /* Dump the EH tree for FN on stderr. */ DEBUG_FUNCTION void debug_eh_tree (struct function *fn) { dump_eh_tree (stderr, fn); } /* Verify invariants on EH datastructures. */ DEBUG_FUNCTION void verify_eh_tree (struct function *fun) { eh_region r, outer; int nvisited_lp, nvisited_r; int count_lp, count_r, depth, i; eh_landing_pad lp; bool err = false; if (!fun->eh->region_tree) return; count_r = 0; for (i = 1; VEC_iterate (eh_region, fun->eh->region_array, i, r); ++i) if (r) { if (r->index == i) count_r++; else { error ("region_array is corrupted for region %i", r->index); err = true; } } count_lp = 0; for (i = 1; VEC_iterate (eh_landing_pad, fun->eh->lp_array, i, lp); ++i) if (lp) { if (lp->index == i) count_lp++; else { error ("lp_array is corrupted for lp %i", lp->index); err = true; } } depth = nvisited_lp = nvisited_r = 0; outer = NULL; r = fun->eh->region_tree; while (1) { if (VEC_index (eh_region, fun->eh->region_array, r->index) != r) { error ("region_array is corrupted for region %i", r->index); err = true; } if (r->outer != outer) { error ("outer block of region %i is wrong", r->index); err = true; } if (depth < 0) { error ("negative nesting depth of region %i", r->index); err = true; } nvisited_r++; for (lp = r->landing_pads; lp ; lp = lp->next_lp) { if (VEC_index (eh_landing_pad, fun->eh->lp_array, lp->index) != lp) { error ("lp_array is corrupted for lp %i", lp->index); err = true; } if (lp->region != r) { error ("region of lp %i is wrong", lp->index); err = true; } nvisited_lp++; } if (r->inner) outer = r, r = r->inner, depth++; else if (r->next_peer) r = r->next_peer; else { do { r = r->outer; if (r == NULL) goto region_done; depth--; outer = r->outer; } while (r->next_peer == NULL); r = r->next_peer; } } region_done: if (depth != 0) { error ("tree list ends on depth %i", depth); err = true; } if (count_r != nvisited_r) { error ("region_array does not match region_tree"); err = true; } if (count_lp != nvisited_lp) { error ("lp_array does not match region_tree"); err = true; } if (err) { dump_eh_tree (stderr, fun); internal_error ("verify_eh_tree failed"); } } #include "gt-except.h"
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