/* Exception Handling interface routines.
- Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001
- Free Software Foundation, Inc.
+ Copyright (C) 1996-2015 Free Software Foundation, Inc.
Contributed by Mike Stump <mrs@cygnus.com>.
-This file is part of GNU CC.
+This file is part of GCC.
-GNU CC 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 2, or (at your option)
-any later version.
+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.
-GNU CC 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.
+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 GNU CC; see the file COPYING. If not, write to
-the Free Software Foundation, 59 Temple Place - Suite 330,
-Boston, MA 02111-1307, USA. */
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
+/* No include guards here, but define an include file marker anyway, so
+ that the compiler can keep track of where this file is included. This
+ is e.g. used to avoid including this file in front-end specific files. */
+#ifndef GCC_EXCEPT_H
+#define GCC_EXCEPT_H
-#ifndef TREE_CODE
-union tree_node;
-#define tree union tree_node *
-#endif
-
-#ifndef RTX_CODE
-struct rtx_def;
-#define rtx struct rtx_def *
-#endif
-
-#ifndef GCC_VARRAY_H
-struct varray_head_tag;
-#define varray_type struct varray_head_tag *
-#endif
-
-
-/* Per-function EH data. Used only in except.c, but GC and others
- manipulate pointers to the opaque type. */
-struct eh_status;
-
-/* Internal structure describing a region. */
-struct eh_region;
-
-/* Test: is exception handling turned on? */
-extern int doing_eh PARAMS ((int));
-
-/* Start an exception handling region. All instructions emitted after
- this point are considered to be part of the region until an
- expand_eh_region_end variant is invoked. */
-extern void expand_eh_region_start PARAMS ((void));
-
-/* End an exception handling region for a cleanup. HANDLER is an
- expression to expand for the cleanup. */
-extern void expand_eh_region_end_cleanup PARAMS ((tree));
-
-/* End an exception handling region for a try block, and prepares
- for subsequent calls to expand_start_catch. */
-extern void expand_start_all_catch PARAMS ((void));
-
-/* Begin a catch clause. TYPE is an object to be matched by the
- runtime, or null if this is a catch-all clause. */
-extern void expand_start_catch PARAMS ((tree));
-
-/* End a catch clause. Control will resume after the try/catch block. */
-extern void expand_end_catch PARAMS ((void));
-
-/* End a sequence of catch handlers for a try block. */
-extern void expand_end_all_catch PARAMS ((void));
-
-/* End an exception region for an exception type filter. ALLOWED is a
- TREE_LIST of TREE_VALUE objects to be matched by the runtime.
- FAILURE is a function to invoke if a mismatch ocurrs. */
-extern void expand_eh_region_end_allowed PARAMS ((tree, tree));
-
-/* End an exception region for a must-not-throw filter. FAILURE is a
- function to invoke if an uncaught exception propagates this far. */
-extern void expand_eh_region_end_must_not_throw PARAMS ((tree));
-
-/* End an exception region for a throw. No handling goes on here,
- but it's the easiest way for the front-end to indicate what type
- is being thrown. */
-extern void expand_eh_region_end_throw PARAMS ((tree));
-
-/* End a fixup region. Within this region the cleanups for the immediately
- enclosing region are _not_ run. This is used for goto cleanup to avoid
- destroying an object twice. */
-extern void expand_eh_region_end_fixup PARAMS ((tree));
-
-/* Begin a region that will contain entries created with
- add_partial_entry. */
-extern void begin_protect_partials PARAMS ((void));
-
-/* Create a new exception region and add the handler for the region
- onto a list. These regions will be ended (and their handlers emitted)
- when end_protect_partials is invoked. */
-extern void add_partial_entry PARAMS ((tree));
-
-/* End all of the pending exception regions that have handlers added with
- add_partial_entry. */
-extern void end_protect_partials PARAMS ((void));
-
-
-/* A list of labels used for exception handlers. */
-extern rtx exception_handler_labels;
-
-/* Determine if the given INSN can throw an exception. */
-extern bool can_throw_internal PARAMS ((rtx));
-extern bool can_throw_external PARAMS ((rtx));
-
-/* Return nonzero if nothing in this function can throw. */
-extern bool nothrow_function_p PARAMS ((void));
-
-/* After initial rtl generation, call back to finish generating
- exception support code. */
-extern void finish_eh_generation PARAMS ((void));
-
-extern void init_eh PARAMS ((void));
-extern void init_eh_for_function PARAMS ((void));
-
-extern rtx reachable_handlers PARAMS ((rtx));
-extern void maybe_remove_eh_handler PARAMS ((rtx));
-
-extern void convert_from_eh_region_ranges PARAMS ((void));
-extern void convert_to_eh_region_ranges PARAMS ((void));
-extern void find_exception_handler_labels PARAMS ((void));
-extern void output_function_exception_table PARAMS ((void));
-
-extern void expand_builtin_unwind_init PARAMS ((void));
-extern rtx expand_builtin_eh_return_data_regno PARAMS ((tree));
-extern rtx expand_builtin_extract_return_addr PARAMS ((tree));
-extern void expand_builtin_init_dwarf_reg_sizes PARAMS ((tree));
-extern rtx expand_builtin_frob_return_addr PARAMS ((tree));
-extern rtx expand_builtin_dwarf_fp_regnum PARAMS ((void));
-extern void expand_builtin_eh_return PARAMS ((tree, tree));
-extern void expand_eh_return PARAMS ((void));
-
-extern rtx get_exception_pointer PARAMS ((struct function *));
struct function;
-struct inline_remap;
-extern int duplicate_eh_regions PARAMS ((struct function *,
- struct inline_remap *));
-
-extern void sjlj_emit_function_exit_after PARAMS ((rtx));
-
-
-/* If non-NULL, this is a function that returns an expression to be
- executed if an unhandled exception is propogated out of a cleanup
- region. For example, in C++, an exception thrown by a destructor
- during stack unwinding is required to result in a call to
- `std::terminate', so the C++ version of this function returns a
- CALL_EXPR for `std::terminate'. */
-extern tree (*lang_protect_cleanup_actions) PARAMS ((void));
-
-/* Return true if type A catches type B. */
-extern int (*lang_eh_type_covers) PARAMS ((tree a, tree b));
-
-/* Map a type to a runtime object to match type. */
-extern tree (*lang_eh_runtime_type) PARAMS ((tree));
-
-#ifndef TREE_CODE
-#undef tree
-#endif
-
-#ifndef RTX_CODE
-#undef rtx
-#endif
-
-#ifndef GCC_VARRAY_H
-#undef varray_type
-#endif
-
-
-/* Just because the user configured --with-sjlj-exceptions=no doesn't
- mean that we can use call frame exceptions. Detect that the target
- has appropriate support. */
-
-#if ! (defined (EH_RETURN_DATA_REGNO) \
- && (defined (IA64_UNWIND_INFO) \
- || (defined (DWARF2_UNWIND_INFO) \
- && defined (EH_RETURN_STACKADJ_RTX) \
- && (defined (EH_RETURN_HANDLER_RTX) \
- || defined (HAVE_eh_return)))))
-#define MUST_USE_SJLJ_EXCEPTIONS 1
-#else
-#define MUST_USE_SJLJ_EXCEPTIONS 0
-#endif
+struct eh_region_d;
+
+/* The type of an exception region. */
+enum eh_region_type
+{
+ /* CLEANUP regions implement e.g. destructors run when exiting a block.
+ They can be generated from both GIMPLE_TRY_FINALLY and GIMPLE_TRY_CATCH
+ nodes. It is expected by the runtime that cleanup regions will *not*
+ resume normal program flow, but will continue propagation of the
+ exception. */
+ ERT_CLEANUP,
+
+ /* TRY regions implement catching an exception. The list of types associated
+ with the attached catch handlers is examined in order by the runtime and
+ control is transferred to the appropriate handler. Note that a NULL type
+ list is a catch-all handler, and that it will catch *all* exceptions
+ including those originating from a different language. */
+ ERT_TRY,
+
+ /* ALLOWED_EXCEPTIONS regions implement exception filtering, e.g. the
+ throw(type-list) specification that can be added to C++ functions.
+ The runtime examines the thrown exception vs the type list, and if
+ the exception does not match, transfers control to the handler. The
+ normal handler for C++ calls __cxa_call_unexpected. */
+ ERT_ALLOWED_EXCEPTIONS,
+
+ /* MUST_NOT_THROW regions prevent all exceptions from propagating. This
+ region type is used in C++ to surround destructors being run inside a
+ CLEANUP region. This differs from an ALLOWED_EXCEPTIONS region with
+ an empty type list in that the runtime is prepared to terminate the
+ program directly. We only generate code for MUST_NOT_THROW regions
+ along control paths that are already handling an exception within the
+ current function. */
+ ERT_MUST_NOT_THROW
+};
+
+
+/* A landing pad for a given exception region. Any transfer of control
+ from the EH runtime to the function happens at a landing pad. */
+
+struct GTY(()) eh_landing_pad_d
+{
+ /* The linked list of all landing pads associated with the region. */
+ struct eh_landing_pad_d *next_lp;
+
+ /* The region with which this landing pad is associated. */
+ struct eh_region_d *region;
+
+ /* At the gimple level, the location to which control will be transferred
+ for this landing pad. There can be both EH and normal edges into the
+ block containing the post-landing-pad label. */
+ tree post_landing_pad;
+
+ /* At the rtl level, the location to which the runtime will transfer
+ control. This differs from the post-landing-pad in that the target's
+ EXCEPTION_RECEIVER pattern will be expanded here, as well as other
+ bookkeeping specific to exceptions. There must not be normal edges
+ into the block containing the landing-pad label. */
+ rtx_code_label *landing_pad;
+
+ /* The index of this landing pad within fun->eh->lp_array. */
+ int index;
+};
+
+/* A catch handler associated with an ERT_TRY region. */
+
+struct GTY(()) eh_catch_d
+{
+ /* The double-linked list of all catch handlers for the region. */
+ struct eh_catch_d *next_catch;
+ struct eh_catch_d *prev_catch;
+
+ /* A TREE_LIST of runtime type objects that this catch handler
+ will catch, or NULL if all exceptions are caught. */
+ tree type_list;
+
+ /* A TREE_LIST of INTEGER_CSTs that correspond to the type_list entries,
+ having been mapped by assign_filter_values. These integers are to be
+ compared against the __builtin_eh_filter value. */
+ tree filter_list;
+
+ /* The code that should be executed if this catch handler matches the
+ thrown exception. This label is only maintained until
+ pass_lower_eh_dispatch, at which point it is cleared. */
+ tree label;
+};
+
+/* Describes one exception region. */
+
+struct GTY(()) eh_region_d
+{
+ /* The immediately surrounding region. */
+ struct eh_region_d *outer;
+
+ /* The list of immediately contained regions. */
+ struct eh_region_d *inner;
+ struct eh_region_d *next_peer;
+
+ /* The index of this region within fun->eh->region_array. */
+ int index;
+
+ /* Each region does exactly one thing. */
+ enum eh_region_type type;
+
+ /* Holds the action to perform based on the preceding type. */
+ union eh_region_u {
+ struct eh_region_u_try {
+ /* The double-linked list of all catch handlers for this region. */
+ struct eh_catch_d *first_catch;
+ struct eh_catch_d *last_catch;
+ } GTY ((tag ("ERT_TRY"))) eh_try;
+
+ struct eh_region_u_allowed {
+ /* A TREE_LIST of runtime type objects allowed to pass. */
+ tree type_list;
+ /* The code that should be executed if the thrown exception does
+ not match the type list. This label is only maintained until
+ pass_lower_eh_dispatch, at which point it is cleared. */
+ tree label;
+ /* The integer that will be passed by the runtime to signal that
+ we should execute the code at LABEL. This integer is assigned
+ by assign_filter_values and is to be compared against the
+ __builtin_eh_filter value. */
+ int filter;
+ } GTY ((tag ("ERT_ALLOWED_EXCEPTIONS"))) allowed;
+
+ struct eh_region_u_must_not_throw {
+ /* A function decl to be invoked if this region is actually reachable
+ from within the function, rather than implementable from the runtime.
+ The normal way for this to happen is for there to be a CLEANUP region
+ contained within this MUST_NOT_THROW region. Note that if the
+ runtime handles the MUST_NOT_THROW region, we have no control over
+ what termination function is called; it will be decided by the
+ personality function in effect for this CIE. */
+ tree failure_decl;
+ /* The location assigned to the call of FAILURE_DECL, if expanded. */
+ location_t failure_loc;
+ } GTY ((tag ("ERT_MUST_NOT_THROW"))) must_not_throw;
+ } GTY ((desc ("%0.type"))) u;
+
+ /* The list of landing pads associated with this region. */
+ struct eh_landing_pad_d *landing_pads;
+
+ /* EXC_PTR and FILTER values copied from the runtime for this region.
+ Each region gets its own psuedos so that if there are nested exceptions
+ we do not overwrite the values of the first exception. */
+ rtx exc_ptr_reg, filter_reg;
+
+ /* True if this region should use __cxa_end_cleanup instead
+ of _Unwind_Resume. */
+ bool use_cxa_end_cleanup;
+};
+
+typedef struct eh_landing_pad_d *eh_landing_pad;
+typedef struct eh_catch_d *eh_catch;
+typedef struct eh_region_d *eh_region;
+
+
+
+
+/* The exception status for each function. */
+
+struct GTY(()) eh_status
+{
+ /* The tree of all regions for this function. */
+ eh_region region_tree;
+
+ /* The same information as an indexable array. */
+ vec<eh_region, va_gc> *region_array;
+
+ /* The landing pads as an indexable array. */
+ vec<eh_landing_pad, va_gc> *lp_array;
+
+ /* At the gimple level, a mapping from gimple statement to landing pad
+ or must-not-throw region. See record_stmt_eh_region. */
+ hash_map<gimple, int> *GTY(()) throw_stmt_table;
+
+ /* All of the runtime type data used by the function. These objects
+ are emitted to the lang-specific-data-area for the function. */
+ vec<tree, va_gc> *ttype_data;
+
+ /* The table of all action chains. These encode the eh_region tree in
+ a compact form for use by the runtime, and is also emitted to the
+ lang-specific-data-area. Note that the ARM EABI uses a different
+ format for the encoding than all other ports. */
+ union eh_status_u {
+ vec<tree, va_gc> *GTY((tag ("1"))) arm_eabi;
+ vec<uchar, va_gc> *GTY((tag ("0"))) other;
+ } GTY ((desc ("targetm.arm_eabi_unwinder"))) ehspec_data;
+};
+
+
+/* Invokes CALLBACK for every exception handler label. Only used by old
+ loop hackery; should not be used by new code. */
+extern void for_each_eh_label (void (*) (rtx));
+
+extern void init_eh_for_function (void);
+
+extern void remove_eh_landing_pad (eh_landing_pad);
+extern void remove_eh_handler (eh_region);
+extern void remove_unreachable_eh_regions (sbitmap);
+
+extern bool current_function_has_exception_handlers (void);
+extern void output_function_exception_table (const char *);
+
+extern rtx expand_builtin_eh_pointer (tree);
+extern rtx expand_builtin_eh_filter (tree);
+extern rtx expand_builtin_eh_copy_values (tree);
+extern void expand_builtin_unwind_init (void);
+extern rtx expand_builtin_eh_return_data_regno (tree);
+extern rtx expand_builtin_extract_return_addr (tree);
+extern void expand_builtin_init_dwarf_reg_sizes (tree);
+extern rtx expand_builtin_frob_return_addr (tree);
+extern rtx expand_builtin_dwarf_sp_column (void);
+extern void expand_builtin_eh_return (tree, tree);
+extern void expand_eh_return (void);
+extern rtx expand_builtin_extend_pointer (tree);
+extern void expand_dw2_landing_pad_for_region (eh_region);
+
+typedef tree (*duplicate_eh_regions_map) (tree, void *);
+extern hash_map<void *, void *> *duplicate_eh_regions
+ (struct function *, eh_region, int, duplicate_eh_regions_map, void *);
+
+extern void sjlj_emit_function_exit_after (rtx_insn *);
+extern void update_sjlj_context (void);
+
+extern eh_region gen_eh_region_cleanup (eh_region);
+extern eh_region gen_eh_region_try (eh_region);
+extern eh_region gen_eh_region_allowed (eh_region, tree);
+extern eh_region gen_eh_region_must_not_throw (eh_region);
+
+extern eh_catch gen_eh_region_catch (eh_region, tree);
+extern eh_landing_pad gen_eh_landing_pad (eh_region);
+
+extern eh_region get_eh_region_from_number_fn (struct function *, int);
+extern eh_region get_eh_region_from_number (int);
+extern eh_landing_pad get_eh_landing_pad_from_number_fn (struct function*,int);
+extern eh_landing_pad get_eh_landing_pad_from_number (int);
+extern eh_region get_eh_region_from_lp_number_fn (struct function *, int);
+extern eh_region get_eh_region_from_lp_number (int);
+
+extern eh_region eh_region_outermost (struct function *, eh_region, eh_region);
+
+extern void make_reg_eh_region_note (rtx_insn *insn, int ecf_flags, int lp_nr);
+extern void make_reg_eh_region_note_nothrow_nononlocal (rtx_insn *);
+
+extern void verify_eh_tree (struct function *);
+extern void dump_eh_tree (FILE *, struct function *);
+void debug_eh_tree (struct function *);
+extern void add_type_for_runtime (tree);
+extern tree lookup_type_for_runtime (tree);
+extern void assign_filter_values (void);
+
+extern eh_region get_eh_region_from_rtx (const_rtx);
+extern eh_landing_pad get_eh_landing_pad_from_rtx (const_rtx);
+
+extern void finish_eh_generation (void);
+
+struct GTY(()) throw_stmt_node {
+ gimple stmt;
+ int lp_nr;
+};
+
+extern hash_map<gimple, int> *get_eh_throw_stmt_table (struct function *);
+extern void set_eh_throw_stmt_table (function *, hash_map<gimple, int> *);
+
+enum eh_personality_kind {
+ eh_personality_none,
+ eh_personality_any,
+ eh_personality_lang
+};
+
+extern enum eh_personality_kind
+function_needs_eh_personality (struct function *);
+
+/* Pre-order iteration within the eh_region tree. */
+
+static inline eh_region
+ehr_next (eh_region r, eh_region start)
+{
+ if (r->inner)
+ r = r->inner;
+ else if (r->next_peer && r != start)
+ r = r->next_peer;
+ else
+ {
+ do
+ {
+ r = r->outer;
+ if (r == start)
+ return NULL;
+ }
+ while (r->next_peer == NULL);
+ r = r->next_peer;
+ }
+ return r;
+}
+
+#define FOR_ALL_EH_REGION_AT(R, START) \
+ for ((R) = (START); (R) != NULL; (R) = ehr_next (R, START))
+
+#define FOR_ALL_EH_REGION_FN(R, FN) \
+ for ((R) = (FN)->eh->region_tree; (R) != NULL; (R) = ehr_next (R, NULL))
+
+#define FOR_ALL_EH_REGION(R) FOR_ALL_EH_REGION_FN (R, cfun)
-#ifdef CONFIG_SJLJ_EXCEPTIONS
-# if CONFIG_SJLJ_EXCEPTIONS == 1
-# define USING_SJLJ_EXCEPTIONS 1
-# endif
-# if CONFIG_SJLJ_EXCEPTIONS == 0
-# define USING_SJLJ_EXCEPTIONS 0
-# ifndef EH_RETURN_DATA_REGNO
- #error "EH_RETURN_DATA_REGNO required"
-# endif
-# ifndef EH_RETURN_STACKADJ_RTX
- #error "EH_RETURN_STACKADJ_RTX required"
-# endif
-# if !defined(EH_RETURN_HANDLER_RTX) && !defined(HAVE_eh_return)
- #error "EH_RETURN_HANDLER_RTX or eh_return required"
-# endif
-# if !defined(DWARF2_UNWIND_INFO) && !defined(IA64_UNWIND_INFO)
- #error "{DWARF2,IA64}_UNWIND_INFO required"
-# endif
-# endif
-#else
-# define USING_SJLJ_EXCEPTIONS MUST_USE_SJLJ_EXCEPTIONS
#endif