X-Git-Url: http://drtracing.org/?a=blobdiff_plain;f=gdb%2Fdwarf2loc.c;h=e8d39feb8e4b93cba688bba384ba67491f763d66;hb=ffda88b4801e1ea163e7eb0962008c60f353c229;hp=a5d10f59de1d07da326f29f5e97ce87fadef4e06;hpb=947bb88ff5da0770e9d6a238b54b7053ba8bd6fb;p=deliverable%2Fbinutils-gdb.git diff --git a/gdb/dwarf2loc.c b/gdb/dwarf2loc.c index a5d10f59de..e8d39feb8e 100644 --- a/gdb/dwarf2loc.c +++ b/gdb/dwarf2loc.c @@ -1,7 +1,6 @@ /* DWARF 2 location expression support for GDB. - Copyright (C) 2003, 2005, 2007, 2008, 2009, 2010 - Free Software Foundation, Inc. + Copyright (C) 2003, 2005, 2007-2012 Free Software Foundation, Inc. Contributed by Daniel Jacobowitz, MontaVista Software, Inc. @@ -33,6 +32,7 @@ #include "objfiles.h" #include "exceptions.h" #include "block.h" +#include "gdbcmd.h" #include "dwarf2.h" #include "dwarf2expr.h" @@ -42,11 +42,156 @@ #include "gdb_string.h" #include "gdb_assert.h" -static void -dwarf_expr_frame_base_1 (struct symbol *framefunc, CORE_ADDR pc, - const gdb_byte **start, size_t *length); +DEF_VEC_I(int); + +extern int dwarf2_always_disassemble; + +static void dwarf_expr_frame_base_1 (struct symbol *framefunc, CORE_ADDR pc, + const gdb_byte **start, size_t *length); + +static const struct dwarf_expr_context_funcs dwarf_expr_ctx_funcs; + +static struct value *dwarf2_evaluate_loc_desc_full (struct type *type, + struct frame_info *frame, + const gdb_byte *data, + size_t size, + struct dwarf2_per_cu_data *per_cu, + LONGEST byte_offset); + +/* Until these have formal names, we define these here. + ref: http://gcc.gnu.org/wiki/DebugFission + Each entry in .debug_loc.dwo begins with a byte that describes the entry, + and is then followed by data specific to that entry. */ + +enum debug_loc_kind +{ + /* Indicates the end of the list of entries. */ + DEBUG_LOC_END_OF_LIST = 0, + + /* This is followed by an unsigned LEB128 number that is an index into + .debug_addr and specifies the base address for all following entries. */ + DEBUG_LOC_BASE_ADDRESS = 1, + + /* This is followed by two unsigned LEB128 numbers that are indices into + .debug_addr and specify the beginning and ending addresses, and then + a normal location expression as in .debug_loc. */ + DEBUG_LOC_START_END = 2, + + /* This is followed by an unsigned LEB128 number that is an index into + .debug_addr and specifies the beginning address, and a 4 byte unsigned + number that specifies the length, and then a normal location expression + as in .debug_loc. */ + DEBUG_LOC_START_LENGTH = 3, + + /* An internal value indicating there is insufficient data. */ + DEBUG_LOC_BUFFER_OVERFLOW = -1, + + /* An internal value indicating an invalid kind of entry was found. */ + DEBUG_LOC_INVALID_ENTRY = -2 +}; + +/* Decode the addresses in a non-dwo .debug_loc entry. + A pointer to the next byte to examine is returned in *NEW_PTR. + The encoded low,high addresses are return in *LOW,*HIGH. + The result indicates the kind of entry found. */ + +static enum debug_loc_kind +decode_debug_loc_addresses (const gdb_byte *loc_ptr, const gdb_byte *buf_end, + const gdb_byte **new_ptr, + CORE_ADDR *low, CORE_ADDR *high, + enum bfd_endian byte_order, + unsigned int addr_size, + int signed_addr_p) +{ + CORE_ADDR base_mask = ~(~(CORE_ADDR)1 << (addr_size * 8 - 1)); + + if (buf_end - loc_ptr < 2 * addr_size) + return DEBUG_LOC_BUFFER_OVERFLOW; + + if (signed_addr_p) + *low = extract_signed_integer (loc_ptr, addr_size, byte_order); + else + *low = extract_unsigned_integer (loc_ptr, addr_size, byte_order); + loc_ptr += addr_size; + + if (signed_addr_p) + *high = extract_signed_integer (loc_ptr, addr_size, byte_order); + else + *high = extract_unsigned_integer (loc_ptr, addr_size, byte_order); + loc_ptr += addr_size; + + *new_ptr = loc_ptr; + + /* A base-address-selection entry. */ + if ((*low & base_mask) == base_mask) + return DEBUG_LOC_BASE_ADDRESS; + + /* An end-of-list entry. */ + if (*low == 0 && *high == 0) + return DEBUG_LOC_END_OF_LIST; + + return DEBUG_LOC_START_END; +} + +/* Decode the addresses in .debug_loc.dwo entry. + A pointer to the next byte to examine is returned in *NEW_PTR. + The encoded low,high addresses are return in *LOW,*HIGH. + The result indicates the kind of entry found. */ + +static enum debug_loc_kind +decode_debug_loc_dwo_addresses (struct dwarf2_per_cu_data *per_cu, + const gdb_byte *loc_ptr, + const gdb_byte *buf_end, + const gdb_byte **new_ptr, + CORE_ADDR *low, CORE_ADDR *high, + enum bfd_endian byte_order) +{ + uint64_t low_index, high_index; + + if (loc_ptr == buf_end) + return DEBUG_LOC_BUFFER_OVERFLOW; + + switch (*loc_ptr++) + { + case DEBUG_LOC_END_OF_LIST: + *new_ptr = loc_ptr; + return DEBUG_LOC_END_OF_LIST; + case DEBUG_LOC_BASE_ADDRESS: + *low = 0; + loc_ptr = gdb_read_uleb128 (loc_ptr, buf_end, &high_index); + if (loc_ptr == NULL) + return DEBUG_LOC_BUFFER_OVERFLOW; + *high = dwarf2_read_addr_index (per_cu, high_index); + *new_ptr = loc_ptr; + return DEBUG_LOC_BASE_ADDRESS; + case DEBUG_LOC_START_END: + loc_ptr = gdb_read_uleb128 (loc_ptr, buf_end, &low_index); + if (loc_ptr == NULL) + return DEBUG_LOC_BUFFER_OVERFLOW; + *low = dwarf2_read_addr_index (per_cu, low_index); + loc_ptr = gdb_read_uleb128 (loc_ptr, buf_end, &high_index); + if (loc_ptr == NULL) + return DEBUG_LOC_BUFFER_OVERFLOW; + *high = dwarf2_read_addr_index (per_cu, high_index); + *new_ptr = loc_ptr; + return DEBUG_LOC_START_END; + case DEBUG_LOC_START_LENGTH: + loc_ptr = gdb_read_uleb128 (loc_ptr, buf_end, &low_index); + if (loc_ptr == NULL) + return DEBUG_LOC_BUFFER_OVERFLOW; + *low = dwarf2_read_addr_index (per_cu, low_index); + if (loc_ptr + 4 > buf_end) + return DEBUG_LOC_BUFFER_OVERFLOW; + *high = *low; + *high += extract_unsigned_integer (loc_ptr, 4, byte_order); + *new_ptr = loc_ptr + 4; + return DEBUG_LOC_START_LENGTH; + default: + return DEBUG_LOC_INVALID_ENTRY; + } +} -/* A helper function for dealing with location lists. Given a +/* A function for dealing with location lists. Given a symbol baton (BATON) and a pc value (PC), find the appropriate location expression, set *LOCEXPR_LENGTH, and return a pointer to the beginning of the expression. Returns NULL on failure. @@ -54,50 +199,59 @@ dwarf_expr_frame_base_1 (struct symbol *framefunc, CORE_ADDR pc, For now, only return the first matching location expression; there can be more than one in the list. */ -static const gdb_byte * -find_location_expression (struct dwarf2_loclist_baton *baton, - size_t *locexpr_length, CORE_ADDR pc) +const gdb_byte * +dwarf2_find_location_expression (struct dwarf2_loclist_baton *baton, + size_t *locexpr_length, CORE_ADDR pc) { - CORE_ADDR low, high; - const gdb_byte *loc_ptr, *buf_end; - int length; struct objfile *objfile = dwarf2_per_cu_objfile (baton->per_cu); struct gdbarch *gdbarch = get_objfile_arch (objfile); enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); unsigned int addr_size = dwarf2_per_cu_addr_size (baton->per_cu); - CORE_ADDR base_mask = ~(~(CORE_ADDR)1 << (addr_size * 8 - 1)); + int signed_addr_p = bfd_get_sign_extend_vma (objfile->obfd); /* Adjust base_address for relocatable objects. */ - CORE_ADDR base_offset = ANOFFSET (objfile->section_offsets, - SECT_OFF_TEXT (objfile)); + CORE_ADDR base_offset = dwarf2_per_cu_text_offset (baton->per_cu); CORE_ADDR base_address = baton->base_address + base_offset; + const gdb_byte *loc_ptr, *buf_end; loc_ptr = baton->data; buf_end = baton->data + baton->size; while (1) { - if (buf_end - loc_ptr < 2 * addr_size) - error (_("find_location_expression: Corrupted DWARF expression.")); - - low = extract_unsigned_integer (loc_ptr, addr_size, byte_order); - loc_ptr += addr_size; - - /* A base-address-selection entry. */ - if (low == base_mask) + CORE_ADDR low = 0, high = 0; /* init for gcc -Wall */ + int length; + enum debug_loc_kind kind; + const gdb_byte *new_ptr = NULL; /* init for gcc -Wall */ + + if (baton->from_dwo) + kind = decode_debug_loc_dwo_addresses (baton->per_cu, + loc_ptr, buf_end, &new_ptr, + &low, &high, byte_order); + else + kind = decode_debug_loc_addresses (loc_ptr, buf_end, &new_ptr, + &low, &high, + byte_order, addr_size, + signed_addr_p); + loc_ptr = new_ptr; + switch (kind) { - base_address = dwarf2_read_address (gdbarch, - loc_ptr, buf_end, addr_size); - loc_ptr += addr_size; + case DEBUG_LOC_END_OF_LIST: + *locexpr_length = 0; + return NULL; + case DEBUG_LOC_BASE_ADDRESS: + base_address = high + base_offset; continue; + case DEBUG_LOC_START_END: + case DEBUG_LOC_START_LENGTH: + break; + case DEBUG_LOC_BUFFER_OVERFLOW: + case DEBUG_LOC_INVALID_ENTRY: + error (_("dwarf2_find_location_expression: " + "Corrupted DWARF expression.")); + default: + gdb_assert_not_reached ("bad debug_loc_kind"); } - high = extract_unsigned_integer (loc_ptr, addr_size, byte_order); - loc_ptr += addr_size; - - /* An end-of-list entry. */ - if (low == 0 && high == 0) - return NULL; - /* Otherwise, a location expression entry. */ low += base_address; high += base_address; @@ -105,6 +259,24 @@ find_location_expression (struct dwarf2_loclist_baton *baton, length = extract_unsigned_integer (loc_ptr, 2, byte_order); loc_ptr += 2; + if (low == high && pc == low) + { + /* This is entry PC record present only at entry point + of a function. Verify it is really the function entry point. */ + + struct block *pc_block = block_for_pc (pc); + struct symbol *pc_func = NULL; + + if (pc_block) + pc_func = block_linkage_function (pc_block); + + if (pc_func && pc == BLOCK_START (SYMBOL_BLOCK_VALUE (pc_func))) + { + *locexpr_length = length; + return loc_ptr; + } + } + if (pc >= low && pc < high) { *locexpr_length = length; @@ -120,7 +292,7 @@ find_location_expression (struct dwarf2_loclist_baton *baton, struct dwarf_expr_baton { struct frame_info *frame; - struct objfile *objfile; + struct dwarf2_per_cu_data *per_cu; }; /* Helper functions for dwarf2_evaluate_loc_desc. */ @@ -181,13 +353,13 @@ dwarf_expr_frame_base_1 (struct symbol *framefunc, CORE_ADDR pc, const gdb_byte **start, size_t *length) { if (SYMBOL_LOCATION_BATON (framefunc) == NULL) - *start = NULL; + *length = 0; else if (SYMBOL_COMPUTED_OPS (framefunc) == &dwarf2_loclist_funcs) { struct dwarf2_loclist_baton *symbaton; symbaton = SYMBOL_LOCATION_BATON (framefunc); - *start = find_location_expression (symbaton, length, pc); + *start = dwarf2_find_location_expression (symbaton, length, pc); } else { @@ -200,10 +372,10 @@ dwarf_expr_frame_base_1 (struct symbol *framefunc, CORE_ADDR pc, *start = symbaton->data; } else - *start = NULL; + *length = 0; } - if (*start == NULL) + if (*length == 0) error (_("Could not find the frame base for \"%s\"."), SYMBOL_NATURAL_NAME (framefunc)); } @@ -219,18 +391,935 @@ dwarf_expr_frame_cfa (void *baton) return dwarf2_frame_cfa (debaton->frame); } +/* Helper function for dwarf2_evaluate_loc_desc. Computes the PC for + the frame in BATON. */ + +static CORE_ADDR +dwarf_expr_frame_pc (void *baton) +{ + struct dwarf_expr_baton *debaton = (struct dwarf_expr_baton *) baton; + + return get_frame_address_in_block (debaton->frame); +} + /* Using the objfile specified in BATON, find the address for the current thread's thread-local storage with offset OFFSET. */ static CORE_ADDR dwarf_expr_tls_address (void *baton, CORE_ADDR offset) { struct dwarf_expr_baton *debaton = (struct dwarf_expr_baton *) baton; + struct objfile *objfile = dwarf2_per_cu_objfile (debaton->per_cu); - return target_translate_tls_address (debaton->objfile, offset); + return target_translate_tls_address (objfile, offset); +} + +/* Call DWARF subroutine from DW_AT_location of DIE at DIE_OFFSET in + current CU (as is PER_CU). State of the CTX is not affected by the + call and return. */ + +static void +per_cu_dwarf_call (struct dwarf_expr_context *ctx, cu_offset die_offset, + struct dwarf2_per_cu_data *per_cu, + CORE_ADDR (*get_frame_pc) (void *baton), + void *baton) +{ + struct dwarf2_locexpr_baton block; + + block = dwarf2_fetch_die_location_block (die_offset, per_cu, + get_frame_pc, baton); + + /* DW_OP_call_ref is currently not supported. */ + gdb_assert (block.per_cu == per_cu); + + dwarf_expr_eval (ctx, block.data, block.size); +} + +/* Helper interface of per_cu_dwarf_call for dwarf2_evaluate_loc_desc. */ + +static void +dwarf_expr_dwarf_call (struct dwarf_expr_context *ctx, cu_offset die_offset) +{ + struct dwarf_expr_baton *debaton = ctx->baton; + + per_cu_dwarf_call (ctx, die_offset, debaton->per_cu, + ctx->funcs->get_frame_pc, ctx->baton); +} + +/* Callback function for dwarf2_evaluate_loc_desc. */ + +static struct type * +dwarf_expr_get_base_type (struct dwarf_expr_context *ctx, + cu_offset die_offset) +{ + struct dwarf_expr_baton *debaton = ctx->baton; + + return dwarf2_get_die_type (die_offset, debaton->per_cu); +} + +/* See dwarf2loc.h. */ + +unsigned int entry_values_debug = 0; + +/* Helper to set entry_values_debug. */ + +static void +show_entry_values_debug (struct ui_file *file, int from_tty, + struct cmd_list_element *c, const char *value) +{ + fprintf_filtered (file, + _("Entry values and tail call frames debugging is %s.\n"), + value); +} + +/* Find DW_TAG_GNU_call_site's DW_AT_GNU_call_site_target address. + CALLER_FRAME (for registers) can be NULL if it is not known. This function + always returns valid address or it throws NO_ENTRY_VALUE_ERROR. */ + +static CORE_ADDR +call_site_to_target_addr (struct gdbarch *call_site_gdbarch, + struct call_site *call_site, + struct frame_info *caller_frame) +{ + switch (FIELD_LOC_KIND (call_site->target)) + { + case FIELD_LOC_KIND_DWARF_BLOCK: + { + struct dwarf2_locexpr_baton *dwarf_block; + struct value *val; + struct type *caller_core_addr_type; + struct gdbarch *caller_arch; + + dwarf_block = FIELD_DWARF_BLOCK (call_site->target); + if (dwarf_block == NULL) + { + struct minimal_symbol *msym; + + msym = lookup_minimal_symbol_by_pc (call_site->pc - 1); + throw_error (NO_ENTRY_VALUE_ERROR, + _("DW_AT_GNU_call_site_target is not specified " + "at %s in %s"), + paddress (call_site_gdbarch, call_site->pc), + msym == NULL ? "???" : SYMBOL_PRINT_NAME (msym)); + + } + if (caller_frame == NULL) + { + struct minimal_symbol *msym; + + msym = lookup_minimal_symbol_by_pc (call_site->pc - 1); + throw_error (NO_ENTRY_VALUE_ERROR, + _("DW_AT_GNU_call_site_target DWARF block resolving " + "requires known frame which is currently not " + "available at %s in %s"), + paddress (call_site_gdbarch, call_site->pc), + msym == NULL ? "???" : SYMBOL_PRINT_NAME (msym)); + + } + caller_arch = get_frame_arch (caller_frame); + caller_core_addr_type = builtin_type (caller_arch)->builtin_func_ptr; + val = dwarf2_evaluate_loc_desc (caller_core_addr_type, caller_frame, + dwarf_block->data, dwarf_block->size, + dwarf_block->per_cu); + /* DW_AT_GNU_call_site_target is a DWARF expression, not a DWARF + location. */ + if (VALUE_LVAL (val) == lval_memory) + return value_address (val); + else + return value_as_address (val); + } + + case FIELD_LOC_KIND_PHYSNAME: + { + const char *physname; + struct minimal_symbol *msym; + + physname = FIELD_STATIC_PHYSNAME (call_site->target); + msym = lookup_minimal_symbol_text (physname, NULL); + if (msym == NULL) + { + msym = lookup_minimal_symbol_by_pc (call_site->pc - 1); + throw_error (NO_ENTRY_VALUE_ERROR, + _("Cannot find function \"%s\" for a call site target " + "at %s in %s"), + physname, paddress (call_site_gdbarch, call_site->pc), + msym == NULL ? "???" : SYMBOL_PRINT_NAME (msym)); + + } + return SYMBOL_VALUE_ADDRESS (msym); + } + + case FIELD_LOC_KIND_PHYSADDR: + return FIELD_STATIC_PHYSADDR (call_site->target); + + default: + internal_error (__FILE__, __LINE__, _("invalid call site target kind")); + } +} + +/* Convert function entry point exact address ADDR to the function which is + compliant with TAIL_CALL_LIST_COMPLETE condition. Throw + NO_ENTRY_VALUE_ERROR otherwise. */ + +static struct symbol * +func_addr_to_tail_call_list (struct gdbarch *gdbarch, CORE_ADDR addr) +{ + struct symbol *sym = find_pc_function (addr); + struct type *type; + + if (sym == NULL || BLOCK_START (SYMBOL_BLOCK_VALUE (sym)) != addr) + throw_error (NO_ENTRY_VALUE_ERROR, + _("DW_TAG_GNU_call_site resolving failed to find function " + "name for address %s"), + paddress (gdbarch, addr)); + + type = SYMBOL_TYPE (sym); + gdb_assert (TYPE_CODE (type) == TYPE_CODE_FUNC); + gdb_assert (TYPE_SPECIFIC_FIELD (type) == TYPE_SPECIFIC_FUNC); + + return sym; +} + +/* Verify function with entry point exact address ADDR can never call itself + via its tail calls (incl. transitively). Throw NO_ENTRY_VALUE_ERROR if it + can call itself via tail calls. + + If a funtion can tail call itself its entry value based parameters are + unreliable. There is no verification whether the value of some/all + parameters is unchanged through the self tail call, we expect if there is + a self tail call all the parameters can be modified. */ + +static void +func_verify_no_selftailcall (struct gdbarch *gdbarch, CORE_ADDR verify_addr) +{ + struct obstack addr_obstack; + struct cleanup *old_chain; + CORE_ADDR addr; + + /* Track here CORE_ADDRs which were already visited. */ + htab_t addr_hash; + + /* The verification is completely unordered. Track here function addresses + which still need to be iterated. */ + VEC (CORE_ADDR) *todo = NULL; + + obstack_init (&addr_obstack); + old_chain = make_cleanup_obstack_free (&addr_obstack); + addr_hash = htab_create_alloc_ex (64, core_addr_hash, core_addr_eq, NULL, + &addr_obstack, hashtab_obstack_allocate, + NULL); + make_cleanup_htab_delete (addr_hash); + + make_cleanup (VEC_cleanup (CORE_ADDR), &todo); + + VEC_safe_push (CORE_ADDR, todo, verify_addr); + while (!VEC_empty (CORE_ADDR, todo)) + { + struct symbol *func_sym; + struct call_site *call_site; + + addr = VEC_pop (CORE_ADDR, todo); + + func_sym = func_addr_to_tail_call_list (gdbarch, addr); + + for (call_site = TYPE_TAIL_CALL_LIST (SYMBOL_TYPE (func_sym)); + call_site; call_site = call_site->tail_call_next) + { + CORE_ADDR target_addr; + void **slot; + + /* CALLER_FRAME with registers is not available for tail-call jumped + frames. */ + target_addr = call_site_to_target_addr (gdbarch, call_site, NULL); + + if (target_addr == verify_addr) + { + struct minimal_symbol *msym; + + msym = lookup_minimal_symbol_by_pc (verify_addr); + throw_error (NO_ENTRY_VALUE_ERROR, + _("DW_OP_GNU_entry_value resolving has found " + "function \"%s\" at %s can call itself via tail " + "calls"), + msym == NULL ? "???" : SYMBOL_PRINT_NAME (msym), + paddress (gdbarch, verify_addr)); + } + + slot = htab_find_slot (addr_hash, &target_addr, INSERT); + if (*slot == NULL) + { + *slot = obstack_copy (&addr_obstack, &target_addr, + sizeof (target_addr)); + VEC_safe_push (CORE_ADDR, todo, target_addr); + } + } + } + + do_cleanups (old_chain); +} + +/* Print user readable form of CALL_SITE->PC to gdb_stdlog. Used only for + ENTRY_VALUES_DEBUG. */ + +static void +tailcall_dump (struct gdbarch *gdbarch, const struct call_site *call_site) +{ + CORE_ADDR addr = call_site->pc; + struct minimal_symbol *msym = lookup_minimal_symbol_by_pc (addr - 1); + + fprintf_unfiltered (gdb_stdlog, " %s(%s)", paddress (gdbarch, addr), + msym == NULL ? "???" : SYMBOL_PRINT_NAME (msym)); + +} + +/* vec.h needs single word type name, typedef it. */ +typedef struct call_site *call_sitep; + +/* Define VEC (call_sitep) functions. */ +DEF_VEC_P (call_sitep); + +/* Intersect RESULTP with CHAIN to keep RESULTP unambiguous, keep in RESULTP + only top callers and bottom callees which are present in both. GDBARCH is + used only for ENTRY_VALUES_DEBUG. RESULTP is NULL after return if there are + no remaining possibilities to provide unambiguous non-trivial result. + RESULTP should point to NULL on the first (initialization) call. Caller is + responsible for xfree of any RESULTP data. */ + +static void +chain_candidate (struct gdbarch *gdbarch, struct call_site_chain **resultp, + VEC (call_sitep) *chain) +{ + struct call_site_chain *result = *resultp; + long length = VEC_length (call_sitep, chain); + int callers, callees, idx; + + if (result == NULL) + { + /* Create the initial chain containing all the passed PCs. */ + + result = xmalloc (sizeof (*result) + sizeof (*result->call_site) + * (length - 1)); + result->length = length; + result->callers = result->callees = length; + memcpy (result->call_site, VEC_address (call_sitep, chain), + sizeof (*result->call_site) * length); + *resultp = result; + + if (entry_values_debug) + { + fprintf_unfiltered (gdb_stdlog, "tailcall: initial:"); + for (idx = 0; idx < length; idx++) + tailcall_dump (gdbarch, result->call_site[idx]); + fputc_unfiltered ('\n', gdb_stdlog); + } + + return; + } + + if (entry_values_debug) + { + fprintf_unfiltered (gdb_stdlog, "tailcall: compare:"); + for (idx = 0; idx < length; idx++) + tailcall_dump (gdbarch, VEC_index (call_sitep, chain, idx)); + fputc_unfiltered ('\n', gdb_stdlog); + } + + /* Intersect callers. */ + + callers = min (result->callers, length); + for (idx = 0; idx < callers; idx++) + if (result->call_site[idx] != VEC_index (call_sitep, chain, idx)) + { + result->callers = idx; + break; + } + + /* Intersect callees. */ + + callees = min (result->callees, length); + for (idx = 0; idx < callees; idx++) + if (result->call_site[result->length - 1 - idx] + != VEC_index (call_sitep, chain, length - 1 - idx)) + { + result->callees = idx; + break; + } + + if (entry_values_debug) + { + fprintf_unfiltered (gdb_stdlog, "tailcall: reduced:"); + for (idx = 0; idx < result->callers; idx++) + tailcall_dump (gdbarch, result->call_site[idx]); + fputs_unfiltered (" |", gdb_stdlog); + for (idx = 0; idx < result->callees; idx++) + tailcall_dump (gdbarch, result->call_site[result->length + - result->callees + idx]); + fputc_unfiltered ('\n', gdb_stdlog); + } + + if (result->callers == 0 && result->callees == 0) + { + /* There are no common callers or callees. It could be also a direct + call (which has length 0) with ambiguous possibility of an indirect + call - CALLERS == CALLEES == 0 is valid during the first allocation + but any subsequence processing of such entry means ambiguity. */ + xfree (result); + *resultp = NULL; + return; + } + + /* See call_site_find_chain_1 why there is no way to reach the bottom callee + PC again. In such case there must be two different code paths to reach + it, therefore some of the former determined intermediate PCs must differ + and the unambiguous chain gets shortened. */ + gdb_assert (result->callers + result->callees < result->length); +} + +/* Create and return call_site_chain for CALLER_PC and CALLEE_PC. All the + assumed frames between them use GDBARCH. Use depth first search so we can + keep single CHAIN of call_site's back to CALLER_PC. Function recursion + would have needless GDB stack overhead. Caller is responsible for xfree of + the returned result. Any unreliability results in thrown + NO_ENTRY_VALUE_ERROR. */ + +static struct call_site_chain * +call_site_find_chain_1 (struct gdbarch *gdbarch, CORE_ADDR caller_pc, + CORE_ADDR callee_pc) +{ + struct obstack addr_obstack; + struct cleanup *back_to_retval, *back_to_workdata; + struct call_site_chain *retval = NULL; + struct call_site *call_site; + + /* Mark CALL_SITEs so we do not visit the same ones twice. */ + htab_t addr_hash; + + /* CHAIN contains only the intermediate CALL_SITEs. Neither CALLER_PC's + call_site nor any possible call_site at CALLEE_PC's function is there. + Any CALL_SITE in CHAIN will be iterated to its siblings - via + TAIL_CALL_NEXT. This is inappropriate for CALLER_PC's call_site. */ + VEC (call_sitep) *chain = NULL; + + /* We are not interested in the specific PC inside the callee function. */ + callee_pc = get_pc_function_start (callee_pc); + if (callee_pc == 0) + throw_error (NO_ENTRY_VALUE_ERROR, _("Unable to find function for PC %s"), + paddress (gdbarch, callee_pc)); + + back_to_retval = make_cleanup (free_current_contents, &retval); + + obstack_init (&addr_obstack); + back_to_workdata = make_cleanup_obstack_free (&addr_obstack); + addr_hash = htab_create_alloc_ex (64, core_addr_hash, core_addr_eq, NULL, + &addr_obstack, hashtab_obstack_allocate, + NULL); + make_cleanup_htab_delete (addr_hash); + + make_cleanup (VEC_cleanup (call_sitep), &chain); + + /* Do not push CALL_SITE to CHAIN. Push there only the first tail call site + at the target's function. All the possible tail call sites in the + target's function will get iterated as already pushed into CHAIN via their + TAIL_CALL_NEXT. */ + call_site = call_site_for_pc (gdbarch, caller_pc); + + while (call_site) + { + CORE_ADDR target_func_addr; + struct call_site *target_call_site; + + /* CALLER_FRAME with registers is not available for tail-call jumped + frames. */ + target_func_addr = call_site_to_target_addr (gdbarch, call_site, NULL); + + if (target_func_addr == callee_pc) + { + chain_candidate (gdbarch, &retval, chain); + if (retval == NULL) + break; + + /* There is no way to reach CALLEE_PC again as we would prevent + entering it twice as being already marked in ADDR_HASH. */ + target_call_site = NULL; + } + else + { + struct symbol *target_func; + + target_func = func_addr_to_tail_call_list (gdbarch, target_func_addr); + target_call_site = TYPE_TAIL_CALL_LIST (SYMBOL_TYPE (target_func)); + } + + do + { + /* Attempt to visit TARGET_CALL_SITE. */ + + if (target_call_site) + { + void **slot; + + slot = htab_find_slot (addr_hash, &target_call_site->pc, INSERT); + if (*slot == NULL) + { + /* Successfully entered TARGET_CALL_SITE. */ + + *slot = &target_call_site->pc; + VEC_safe_push (call_sitep, chain, target_call_site); + break; + } + } + + /* Backtrack (without revisiting the originating call_site). Try the + callers's sibling; if there isn't any try the callers's callers's + sibling etc. */ + + target_call_site = NULL; + while (!VEC_empty (call_sitep, chain)) + { + call_site = VEC_pop (call_sitep, chain); + + gdb_assert (htab_find_slot (addr_hash, &call_site->pc, + NO_INSERT) != NULL); + htab_remove_elt (addr_hash, &call_site->pc); + + target_call_site = call_site->tail_call_next; + if (target_call_site) + break; + } + } + while (target_call_site); + + if (VEC_empty (call_sitep, chain)) + call_site = NULL; + else + call_site = VEC_last (call_sitep, chain); + } + + if (retval == NULL) + { + struct minimal_symbol *msym_caller, *msym_callee; + + msym_caller = lookup_minimal_symbol_by_pc (caller_pc); + msym_callee = lookup_minimal_symbol_by_pc (callee_pc); + throw_error (NO_ENTRY_VALUE_ERROR, + _("There are no unambiguously determinable intermediate " + "callers or callees between caller function \"%s\" at %s " + "and callee function \"%s\" at %s"), + (msym_caller == NULL + ? "???" : SYMBOL_PRINT_NAME (msym_caller)), + paddress (gdbarch, caller_pc), + (msym_callee == NULL + ? "???" : SYMBOL_PRINT_NAME (msym_callee)), + paddress (gdbarch, callee_pc)); + } + + do_cleanups (back_to_workdata); + discard_cleanups (back_to_retval); + return retval; +} + +/* Create and return call_site_chain for CALLER_PC and CALLEE_PC. All the + assumed frames between them use GDBARCH. If valid call_site_chain cannot be + constructed return NULL. Caller is responsible for xfree of the returned + result. */ + +struct call_site_chain * +call_site_find_chain (struct gdbarch *gdbarch, CORE_ADDR caller_pc, + CORE_ADDR callee_pc) +{ + volatile struct gdb_exception e; + struct call_site_chain *retval = NULL; + + TRY_CATCH (e, RETURN_MASK_ERROR) + { + retval = call_site_find_chain_1 (gdbarch, caller_pc, callee_pc); + } + if (e.reason < 0) + { + if (e.error == NO_ENTRY_VALUE_ERROR) + { + if (entry_values_debug) + exception_print (gdb_stdout, e); + + return NULL; + } + else + throw_exception (e); + } + return retval; +} + +/* Return 1 if KIND and KIND_U match PARAMETER. Return 0 otherwise. */ + +static int +call_site_parameter_matches (struct call_site_parameter *parameter, + enum call_site_parameter_kind kind, + union call_site_parameter_u kind_u) +{ + if (kind == parameter->kind) + switch (kind) + { + case CALL_SITE_PARAMETER_DWARF_REG: + return kind_u.dwarf_reg == parameter->u.dwarf_reg; + case CALL_SITE_PARAMETER_FB_OFFSET: + return kind_u.fb_offset == parameter->u.fb_offset; + case CALL_SITE_PARAMETER_PARAM_OFFSET: + return kind_u.param_offset.cu_off == parameter->u.param_offset.cu_off; + } + return 0; +} + +/* Fetch call_site_parameter from caller matching KIND and KIND_U. + FRAME is for callee. + + Function always returns non-NULL, it throws NO_ENTRY_VALUE_ERROR + otherwise. */ + +static struct call_site_parameter * +dwarf_expr_reg_to_entry_parameter (struct frame_info *frame, + enum call_site_parameter_kind kind, + union call_site_parameter_u kind_u, + struct dwarf2_per_cu_data **per_cu_return) +{ + CORE_ADDR func_addr = get_frame_func (frame); + CORE_ADDR caller_pc; + struct gdbarch *gdbarch = get_frame_arch (frame); + struct frame_info *caller_frame = get_prev_frame (frame); + struct call_site *call_site; + int iparams; + /* Initialize it just to avoid a GCC false warning. */ + struct call_site_parameter *parameter = NULL; + CORE_ADDR target_addr; + + if (gdbarch != frame_unwind_arch (frame)) + { + struct minimal_symbol *msym = lookup_minimal_symbol_by_pc (func_addr); + struct gdbarch *caller_gdbarch = frame_unwind_arch (frame); + + throw_error (NO_ENTRY_VALUE_ERROR, + _("DW_OP_GNU_entry_value resolving callee gdbarch %s " + "(of %s (%s)) does not match caller gdbarch %s"), + gdbarch_bfd_arch_info (gdbarch)->printable_name, + paddress (gdbarch, func_addr), + msym == NULL ? "???" : SYMBOL_PRINT_NAME (msym), + gdbarch_bfd_arch_info (caller_gdbarch)->printable_name); + } + + if (caller_frame == NULL) + { + struct minimal_symbol *msym = lookup_minimal_symbol_by_pc (func_addr); + + throw_error (NO_ENTRY_VALUE_ERROR, _("DW_OP_GNU_entry_value resolving " + "requires caller of %s (%s)"), + paddress (gdbarch, func_addr), + msym == NULL ? "???" : SYMBOL_PRINT_NAME (msym)); + } + caller_pc = get_frame_pc (caller_frame); + call_site = call_site_for_pc (gdbarch, caller_pc); + + target_addr = call_site_to_target_addr (gdbarch, call_site, caller_frame); + if (target_addr != func_addr) + { + struct minimal_symbol *target_msym, *func_msym; + + target_msym = lookup_minimal_symbol_by_pc (target_addr); + func_msym = lookup_minimal_symbol_by_pc (func_addr); + throw_error (NO_ENTRY_VALUE_ERROR, + _("DW_OP_GNU_entry_value resolving expects callee %s at %s " + "but the called frame is for %s at %s"), + (target_msym == NULL ? "???" + : SYMBOL_PRINT_NAME (target_msym)), + paddress (gdbarch, target_addr), + func_msym == NULL ? "???" : SYMBOL_PRINT_NAME (func_msym), + paddress (gdbarch, func_addr)); + } + + /* No entry value based parameters would be reliable if this function can + call itself via tail calls. */ + func_verify_no_selftailcall (gdbarch, func_addr); + + for (iparams = 0; iparams < call_site->parameter_count; iparams++) + { + parameter = &call_site->parameter[iparams]; + if (call_site_parameter_matches (parameter, kind, kind_u)) + break; + } + if (iparams == call_site->parameter_count) + { + struct minimal_symbol *msym = lookup_minimal_symbol_by_pc (caller_pc); + + /* DW_TAG_GNU_call_site_parameter will be missing just if GCC could not + determine its value. */ + throw_error (NO_ENTRY_VALUE_ERROR, _("Cannot find matching parameter " + "at DW_TAG_GNU_call_site %s at %s"), + paddress (gdbarch, caller_pc), + msym == NULL ? "???" : SYMBOL_PRINT_NAME (msym)); + } + + *per_cu_return = call_site->per_cu; + return parameter; +} + +/* Return value for PARAMETER matching DEREF_SIZE. If DEREF_SIZE is -1, return + the normal DW_AT_GNU_call_site_value block. Otherwise return the + DW_AT_GNU_call_site_data_value (dereferenced) block. + + TYPE and CALLER_FRAME specify how to evaluate the DWARF block into returned + struct value. + + Function always returns non-NULL, non-optimized out value. It throws + NO_ENTRY_VALUE_ERROR if it cannot resolve the value for any reason. */ + +static struct value * +dwarf_entry_parameter_to_value (struct call_site_parameter *parameter, + CORE_ADDR deref_size, struct type *type, + struct frame_info *caller_frame, + struct dwarf2_per_cu_data *per_cu) +{ + const gdb_byte *data_src; + gdb_byte *data; + size_t size; + + data_src = deref_size == -1 ? parameter->value : parameter->data_value; + size = deref_size == -1 ? parameter->value_size : parameter->data_value_size; + + /* DEREF_SIZE size is not verified here. */ + if (data_src == NULL) + throw_error (NO_ENTRY_VALUE_ERROR, + _("Cannot resolve DW_AT_GNU_call_site_data_value")); + + /* DW_AT_GNU_call_site_value is a DWARF expression, not a DWARF + location. Postprocessing of DWARF_VALUE_MEMORY would lose the type from + DWARF block. */ + data = alloca (size + 1); + memcpy (data, data_src, size); + data[size] = DW_OP_stack_value; + + return dwarf2_evaluate_loc_desc (type, caller_frame, data, size + 1, per_cu); +} + +/* Execute DWARF block of call_site_parameter which matches KIND and KIND_U. + Choose DEREF_SIZE value of that parameter. Search caller of the CTX's + frame. CTX must be of dwarf_expr_ctx_funcs kind. + + The CTX caller can be from a different CU - per_cu_dwarf_call implementation + can be more simple as it does not support cross-CU DWARF executions. */ + +static void +dwarf_expr_push_dwarf_reg_entry_value (struct dwarf_expr_context *ctx, + enum call_site_parameter_kind kind, + union call_site_parameter_u kind_u, + int deref_size) +{ + struct dwarf_expr_baton *debaton; + struct frame_info *frame, *caller_frame; + struct dwarf2_per_cu_data *caller_per_cu; + struct dwarf_expr_baton baton_local; + struct dwarf_expr_context saved_ctx; + struct call_site_parameter *parameter; + const gdb_byte *data_src; + size_t size; + + gdb_assert (ctx->funcs == &dwarf_expr_ctx_funcs); + debaton = ctx->baton; + frame = debaton->frame; + caller_frame = get_prev_frame (frame); + + parameter = dwarf_expr_reg_to_entry_parameter (frame, kind, kind_u, + &caller_per_cu); + data_src = deref_size == -1 ? parameter->value : parameter->data_value; + size = deref_size == -1 ? parameter->value_size : parameter->data_value_size; + + /* DEREF_SIZE size is not verified here. */ + if (data_src == NULL) + throw_error (NO_ENTRY_VALUE_ERROR, + _("Cannot resolve DW_AT_GNU_call_site_data_value")); + + baton_local.frame = caller_frame; + baton_local.per_cu = caller_per_cu; + + saved_ctx.gdbarch = ctx->gdbarch; + saved_ctx.addr_size = ctx->addr_size; + saved_ctx.offset = ctx->offset; + saved_ctx.baton = ctx->baton; + ctx->gdbarch = get_objfile_arch (dwarf2_per_cu_objfile (baton_local.per_cu)); + ctx->addr_size = dwarf2_per_cu_addr_size (baton_local.per_cu); + ctx->offset = dwarf2_per_cu_text_offset (baton_local.per_cu); + ctx->baton = &baton_local; + + dwarf_expr_eval (ctx, data_src, size); + + ctx->gdbarch = saved_ctx.gdbarch; + ctx->addr_size = saved_ctx.addr_size; + ctx->offset = saved_ctx.offset; + ctx->baton = saved_ctx.baton; +} + +/* Callback function for dwarf2_evaluate_loc_desc. + Fetch the address indexed by DW_OP_GNU_addr_index. */ + +static CORE_ADDR +dwarf_expr_get_addr_index (void *baton, unsigned int index) +{ + struct dwarf_expr_baton *debaton = (struct dwarf_expr_baton *) baton; + + return dwarf2_read_addr_index (debaton->per_cu, index); +} + +/* VALUE must be of type lval_computed with entry_data_value_funcs. Perform + the indirect method on it, that is use its stored target value, the sole + purpose of entry_data_value_funcs.. */ + +static struct value * +entry_data_value_coerce_ref (const struct value *value) +{ + struct type *checked_type = check_typedef (value_type (value)); + struct value *target_val; + + if (TYPE_CODE (checked_type) != TYPE_CODE_REF) + return NULL; + + target_val = value_computed_closure (value); + value_incref (target_val); + return target_val; +} + +/* Implement copy_closure. */ + +static void * +entry_data_value_copy_closure (const struct value *v) +{ + struct value *target_val = value_computed_closure (v); + + value_incref (target_val); + return target_val; +} + +/* Implement free_closure. */ + +static void +entry_data_value_free_closure (struct value *v) +{ + struct value *target_val = value_computed_closure (v); + + value_free (target_val); +} + +/* Vector for methods for an entry value reference where the referenced value + is stored in the caller. On the first dereference use + DW_AT_GNU_call_site_data_value in the caller. */ + +static const struct lval_funcs entry_data_value_funcs = +{ + NULL, /* read */ + NULL, /* write */ + NULL, /* check_validity */ + NULL, /* check_any_valid */ + NULL, /* indirect */ + entry_data_value_coerce_ref, + NULL, /* check_synthetic_pointer */ + entry_data_value_copy_closure, + entry_data_value_free_closure +}; + +/* Read parameter of TYPE at (callee) FRAME's function entry. KIND and KIND_U + are used to match DW_AT_location at the caller's + DW_TAG_GNU_call_site_parameter. + + Function always returns non-NULL value. It throws NO_ENTRY_VALUE_ERROR if it + cannot resolve the parameter for any reason. */ + +static struct value * +value_of_dwarf_reg_entry (struct type *type, struct frame_info *frame, + enum call_site_parameter_kind kind, + union call_site_parameter_u kind_u) +{ + struct type *checked_type = check_typedef (type); + struct type *target_type = TYPE_TARGET_TYPE (checked_type); + struct frame_info *caller_frame = get_prev_frame (frame); + struct value *outer_val, *target_val, *val; + struct call_site_parameter *parameter; + struct dwarf2_per_cu_data *caller_per_cu; + CORE_ADDR addr; + + parameter = dwarf_expr_reg_to_entry_parameter (frame, kind, kind_u, + &caller_per_cu); + + outer_val = dwarf_entry_parameter_to_value (parameter, -1 /* deref_size */, + type, caller_frame, + caller_per_cu); + + /* Check if DW_AT_GNU_call_site_data_value cannot be used. If it should be + used and it is not available do not fall back to OUTER_VAL - dereferencing + TYPE_CODE_REF with non-entry data value would give current value - not the + entry value. */ + + if (TYPE_CODE (checked_type) != TYPE_CODE_REF + || TYPE_TARGET_TYPE (checked_type) == NULL) + return outer_val; + + target_val = dwarf_entry_parameter_to_value (parameter, + TYPE_LENGTH (target_type), + target_type, caller_frame, + caller_per_cu); + + /* value_as_address dereferences TYPE_CODE_REF. */ + addr = extract_typed_address (value_contents (outer_val), checked_type); + + /* The target entry value has artificial address of the entry value + reference. */ + VALUE_LVAL (target_val) = lval_memory; + set_value_address (target_val, addr); + + release_value (target_val); + val = allocate_computed_value (type, &entry_data_value_funcs, + target_val /* closure */); + + /* Copy the referencing pointer to the new computed value. */ + memcpy (value_contents_raw (val), value_contents_raw (outer_val), + TYPE_LENGTH (checked_type)); + set_value_lazy (val, 0); + + return val; +} + +/* Read parameter of TYPE at (callee) FRAME's function entry. DATA and + SIZE are DWARF block used to match DW_AT_location at the caller's + DW_TAG_GNU_call_site_parameter. + + Function always returns non-NULL value. It throws NO_ENTRY_VALUE_ERROR if it + cannot resolve the parameter for any reason. */ + +static struct value * +value_of_dwarf_block_entry (struct type *type, struct frame_info *frame, + const gdb_byte *block, size_t block_len) +{ + union call_site_parameter_u kind_u; + + kind_u.dwarf_reg = dwarf_block_to_dwarf_reg (block, block + block_len); + if (kind_u.dwarf_reg != -1) + return value_of_dwarf_reg_entry (type, frame, CALL_SITE_PARAMETER_DWARF_REG, + kind_u); + + if (dwarf_block_to_fb_offset (block, block + block_len, &kind_u.fb_offset)) + return value_of_dwarf_reg_entry (type, frame, CALL_SITE_PARAMETER_FB_OFFSET, + kind_u); + + /* This can normally happen - throw NO_ENTRY_VALUE_ERROR to get the message + suppressed during normal operation. The expression can be arbitrary if + there is no caller-callee entry value binding expected. */ + throw_error (NO_ENTRY_VALUE_ERROR, + _("DWARF-2 expression error: DW_OP_GNU_entry_value is supported " + "only for single DW_OP_reg* or for DW_OP_fbreg(*)")); } struct piece_closure { + /* Reference count. */ + int refc; + + /* The CU from which this closure's expression came. */ + struct dwarf2_per_cu_data *per_cu; + /* The number of pieces used to describe this variable. */ int n_pieces; @@ -245,16 +1334,23 @@ struct piece_closure PIECES. */ static struct piece_closure * -allocate_piece_closure (int n_pieces, struct dwarf_expr_piece *pieces, +allocate_piece_closure (struct dwarf2_per_cu_data *per_cu, + int n_pieces, struct dwarf_expr_piece *pieces, int addr_size) { struct piece_closure *c = XZALLOC (struct piece_closure); + int i; + c->refc = 1; + c->per_cu = per_cu; c->n_pieces = n_pieces; c->addr_size = addr_size; c->pieces = XCALLOC (n_pieces, struct dwarf_expr_piece); memcpy (c->pieces, pieces, n_pieces * sizeof (struct dwarf_expr_piece)); + for (i = 0; i < n_pieces; ++i) + if (c->pieces[i].location == DWARF_VALUE_STACK) + value_incref (c->pieces[i].v.value); return c; } @@ -356,7 +1452,7 @@ insert_bits (unsigned int datum, { unsigned int mask; - gdb_assert (dest_offset_bits >= 0 && dest_offset_bits + nbits <= 8); + gdb_assert (dest_offset_bits + nbits <= 8); mask = (1 << nbits) - 1; if (bits_big_endian) @@ -438,7 +1534,8 @@ read_pieced_value (struct value *v) long offset = 0; ULONGEST bits_to_skip; gdb_byte *contents; - struct piece_closure *c = (struct piece_closure *) value_computed_closure (v); + struct piece_closure *c + = (struct piece_closure *) value_computed_closure (v); struct frame_info *frame = frame_find_by_id (VALUE_FRAME_ID (v)); size_t type_len; size_t buffer_size = 0; @@ -456,7 +1553,13 @@ read_pieced_value (struct value *v) contents = value_contents_raw (v); bits_to_skip = 8 * value_offset (v); - type_len = 8 * TYPE_LENGTH (value_type (v)); + if (value_bitsize (v)) + { + bits_to_skip += value_bitpos (v); + type_len = value_bitsize (v); + } + else + type_len = 8 * TYPE_LENGTH (value_type (v)); for (i = 0; i < c->n_pieces && offset < type_len; i++) { @@ -503,8 +1606,7 @@ read_pieced_value (struct value *v) case DWARF_VALUE_REGISTER: { struct gdbarch *arch = get_frame_arch (frame); - int gdb_regnum = gdbarch_dwarf2_reg_to_regnum (arch, - p->v.expr.value); + int gdb_regnum = gdbarch_dwarf2_reg_to_regnum (arch, p->v.regno); int reg_offset = source_offset; if (gdbarch_byte_order (arch) == BFD_ENDIAN_BIG @@ -519,27 +1621,38 @@ read_pieced_value (struct value *v) if (gdb_regnum != -1) { - get_frame_register_bytes (frame, gdb_regnum, reg_offset, - this_size, buffer); + int optim, unavail; + + if (!get_frame_register_bytes (frame, gdb_regnum, reg_offset, + this_size, buffer, + &optim, &unavail)) + { + /* Just so garbage doesn't ever shine through. */ + memset (buffer, 0, this_size); + + if (optim) + set_value_optimized_out (v, 1); + if (unavail) + mark_value_bytes_unavailable (v, offset, this_size); + } } else { error (_("Unable to access DWARF register number %s"), - paddress (arch, p->v.expr.value)); + paddress (arch, p->v.regno)); } } break; case DWARF_VALUE_MEMORY: - if (p->v.expr.in_stack_memory) - read_stack (p->v.expr.value + source_offset, buffer, this_size); - else - read_memory (p->v.expr.value + source_offset, buffer, this_size); + read_value_memory (v, offset, + p->v.mem.in_stack_memory, + p->v.mem.addr + source_offset, + buffer, this_size); break; case DWARF_VALUE_STACK: { - struct gdbarch *gdbarch = get_type_arch (value_type (v)); size_t n = this_size; if (n > c->addr_size - source_offset) @@ -550,18 +1663,11 @@ read_pieced_value (struct value *v) { /* Nothing. */ } - else if (source_offset == 0) - store_unsigned_integer (buffer, n, - gdbarch_byte_order (gdbarch), - p->v.expr.value); else { - gdb_byte bytes[sizeof (ULONGEST)]; + const gdb_byte *val_bytes = value_contents_all (p->v.value); - store_unsigned_integer (bytes, n + source_offset, - gdbarch_byte_order (gdbarch), - p->v.expr.value); - memcpy (buffer, bytes + source_offset, n); + intermediate_buffer = val_bytes + source_offset; } } break; @@ -579,21 +1685,21 @@ read_pieced_value (struct value *v) } break; + /* These bits show up as zeros -- but do not cause the value + to be considered optimized-out. */ + case DWARF_VALUE_IMPLICIT_POINTER: + break; + case DWARF_VALUE_OPTIMIZED_OUT: - /* We just leave the bits empty for now. This is not ideal - but gdb currently does not have a nice way to represent - optimized-out pieces. */ - warning (_("bits %ld-%ld in computed object were optimized out; " - "replacing with zeroes"), - offset, - offset + (long) this_size_bits); + set_value_optimized_out (v, 1); break; default: internal_error (__FILE__, __LINE__, _("invalid location type")); } - if (p->location != DWARF_VALUE_OPTIMIZED_OUT) + if (p->location != DWARF_VALUE_OPTIMIZED_OUT + && p->location != DWARF_VALUE_IMPLICIT_POINTER) copy_bitwise (contents, dest_offset_bits, intermediate_buffer, source_offset_bits % 8, this_size_bits, bits_big_endian); @@ -611,7 +1717,8 @@ write_pieced_value (struct value *to, struct value *from) long offset = 0; ULONGEST bits_to_skip; const gdb_byte *contents; - struct piece_closure *c = (struct piece_closure *) value_computed_closure (to); + struct piece_closure *c + = (struct piece_closure *) value_computed_closure (to); struct frame_info *frame = frame_find_by_id (VALUE_FRAME_ID (to)); size_t type_len; size_t buffer_size = 0; @@ -630,7 +1737,14 @@ write_pieced_value (struct value *to, struct value *from) contents = value_contents (from); bits_to_skip = 8 * value_offset (to); - type_len = 8 * TYPE_LENGTH (value_type (to)); + if (value_bitsize (to)) + { + bits_to_skip += value_bitpos (to); + type_len = value_bitsize (to); + } + else + type_len = 8 * TYPE_LENGTH (value_type (to)); + for (i = 0; i < c->n_pieces && offset < type_len; i++) { struct dwarf_expr_piece *p = &c->pieces[i]; @@ -684,7 +1798,7 @@ write_pieced_value (struct value *to, struct value *from) case DWARF_VALUE_REGISTER: { struct gdbarch *arch = get_frame_arch (frame); - int gdb_regnum = gdbarch_dwarf2_reg_to_regnum (arch, p->v.expr.value); + int gdb_regnum = gdbarch_dwarf2_reg_to_regnum (arch, p->v.regno); int reg_offset = dest_offset; if (gdbarch_byte_order (arch) == BFD_ENDIAN_BIG @@ -696,8 +1810,22 @@ write_pieced_value (struct value *to, struct value *from) { if (need_bitwise) { - get_frame_register_bytes (frame, gdb_regnum, reg_offset, - this_size, buffer); + int optim, unavail; + + if (!get_frame_register_bytes (frame, gdb_regnum, reg_offset, + this_size, buffer, + &optim, &unavail)) + { + if (optim) + error (_("Can't do read-modify-write to " + "update bitfield; containing word has been " + "optimized out")); + if (unavail) + throw_error (NOT_AVAILABLE_ERROR, + _("Can't do read-modify-write to update " + "bitfield; containing word " + "is unavailable")); + } copy_bitwise (buffer, dest_offset_bits, contents, source_offset_bits, this_size_bits, @@ -710,7 +1838,7 @@ write_pieced_value (struct value *to, struct value *from) else { error (_("Unable to write to DWARF register number %s"), - paddress (arch, p->v.expr.value)); + paddress (arch, p->v.regno)); } } break; @@ -719,8 +1847,8 @@ write_pieced_value (struct value *to, struct value *from) { /* Only the first and last bytes can possibly have any bits reused. */ - read_memory (p->v.expr.value + dest_offset, buffer, 1); - read_memory (p->v.expr.value + dest_offset + this_size - 1, + read_memory (p->v.mem.addr + dest_offset, buffer, 1); + read_memory (p->v.mem.addr + dest_offset + this_size - 1, buffer + this_size - 1, 1); copy_bitwise (buffer, dest_offset_bits, contents, source_offset_bits, @@ -728,92 +1856,336 @@ write_pieced_value (struct value *to, struct value *from) bits_big_endian); } - write_memory (p->v.expr.value + dest_offset, + write_memory (p->v.mem.addr + dest_offset, source_buffer, this_size); break; default: set_value_optimized_out (to, 1); - goto done; + break; } offset += this_size_bits; } - done: do_cleanups (cleanup); } +/* A helper function that checks bit validity in a pieced value. + CHECK_FOR indicates the kind of validity checking. + DWARF_VALUE_MEMORY means to check whether any bit is valid. + DWARF_VALUE_OPTIMIZED_OUT means to check whether any bit is + optimized out. + DWARF_VALUE_IMPLICIT_POINTER means to check whether the bits are an + implicit pointer. */ + +static int +check_pieced_value_bits (const struct value *value, int bit_offset, + int bit_length, + enum dwarf_value_location check_for) +{ + struct piece_closure *c + = (struct piece_closure *) value_computed_closure (value); + int i; + int validity = (check_for == DWARF_VALUE_MEMORY + || check_for == DWARF_VALUE_IMPLICIT_POINTER); + + bit_offset += 8 * value_offset (value); + if (value_bitsize (value)) + bit_offset += value_bitpos (value); + + for (i = 0; i < c->n_pieces && bit_length > 0; i++) + { + struct dwarf_expr_piece *p = &c->pieces[i]; + size_t this_size_bits = p->size; + + if (bit_offset > 0) + { + if (bit_offset >= this_size_bits) + { + bit_offset -= this_size_bits; + continue; + } + + bit_length -= this_size_bits - bit_offset; + bit_offset = 0; + } + else + bit_length -= this_size_bits; + + if (check_for == DWARF_VALUE_IMPLICIT_POINTER) + { + if (p->location != DWARF_VALUE_IMPLICIT_POINTER) + return 0; + } + else if (p->location == DWARF_VALUE_OPTIMIZED_OUT + || p->location == DWARF_VALUE_IMPLICIT_POINTER) + { + if (validity) + return 0; + } + else + { + if (!validity) + return 1; + } + } + + return validity; +} + +static int +check_pieced_value_validity (const struct value *value, int bit_offset, + int bit_length) +{ + return check_pieced_value_bits (value, bit_offset, bit_length, + DWARF_VALUE_MEMORY); +} + +static int +check_pieced_value_invalid (const struct value *value) +{ + return check_pieced_value_bits (value, 0, + 8 * TYPE_LENGTH (value_type (value)), + DWARF_VALUE_OPTIMIZED_OUT); +} + +/* An implementation of an lval_funcs method to see whether a value is + a synthetic pointer. */ + +static int +check_pieced_synthetic_pointer (const struct value *value, int bit_offset, + int bit_length) +{ + return check_pieced_value_bits (value, bit_offset, bit_length, + DWARF_VALUE_IMPLICIT_POINTER); +} + +/* A wrapper function for get_frame_address_in_block. */ + +static CORE_ADDR +get_frame_address_in_block_wrapper (void *baton) +{ + return get_frame_address_in_block (baton); +} + +/* An implementation of an lval_funcs method to indirect through a + pointer. This handles the synthetic pointer case when needed. */ + +static struct value * +indirect_pieced_value (struct value *value) +{ + struct piece_closure *c + = (struct piece_closure *) value_computed_closure (value); + struct type *type; + struct frame_info *frame; + struct dwarf2_locexpr_baton baton; + int i, bit_offset, bit_length; + struct dwarf_expr_piece *piece = NULL; + LONGEST byte_offset; + + type = check_typedef (value_type (value)); + if (TYPE_CODE (type) != TYPE_CODE_PTR) + return NULL; + + bit_length = 8 * TYPE_LENGTH (type); + bit_offset = 8 * value_offset (value); + if (value_bitsize (value)) + bit_offset += value_bitpos (value); + + for (i = 0; i < c->n_pieces && bit_length > 0; i++) + { + struct dwarf_expr_piece *p = &c->pieces[i]; + size_t this_size_bits = p->size; + + if (bit_offset > 0) + { + if (bit_offset >= this_size_bits) + { + bit_offset -= this_size_bits; + continue; + } + + bit_length -= this_size_bits - bit_offset; + bit_offset = 0; + } + else + bit_length -= this_size_bits; + + if (p->location != DWARF_VALUE_IMPLICIT_POINTER) + return NULL; + + if (bit_length != 0) + error (_("Invalid use of DW_OP_GNU_implicit_pointer")); + + piece = p; + break; + } + + frame = get_selected_frame (_("No frame selected.")); + + /* This is an offset requested by GDB, such as value subcripts. */ + byte_offset = value_as_address (value); + + gdb_assert (piece); + baton = dwarf2_fetch_die_location_block (piece->v.ptr.die, c->per_cu, + get_frame_address_in_block_wrapper, + frame); + + return dwarf2_evaluate_loc_desc_full (TYPE_TARGET_TYPE (type), frame, + baton.data, baton.size, baton.per_cu, + piece->v.ptr.offset + byte_offset); +} + static void * -copy_pieced_value_closure (struct value *v) +copy_pieced_value_closure (const struct value *v) { - struct piece_closure *c = (struct piece_closure *) value_computed_closure (v); + struct piece_closure *c + = (struct piece_closure *) value_computed_closure (v); - return allocate_piece_closure (c->n_pieces, c->pieces, c->addr_size); + ++c->refc; + return c; } static void free_pieced_value_closure (struct value *v) { - struct piece_closure *c = (struct piece_closure *) value_computed_closure (v); + struct piece_closure *c + = (struct piece_closure *) value_computed_closure (v); + + --c->refc; + if (c->refc == 0) + { + int i; - xfree (c->pieces); - xfree (c); + for (i = 0; i < c->n_pieces; ++i) + if (c->pieces[i].location == DWARF_VALUE_STACK) + value_free (c->pieces[i].v.value); + + xfree (c->pieces); + xfree (c); + } } /* Functions for accessing a variable described by DW_OP_piece. */ -static struct lval_funcs pieced_value_funcs = { +static const struct lval_funcs pieced_value_funcs = { read_pieced_value, write_pieced_value, + check_pieced_value_validity, + check_pieced_value_invalid, + indirect_pieced_value, + NULL, /* coerce_ref */ + check_pieced_synthetic_pointer, copy_pieced_value_closure, free_pieced_value_closure }; +/* Helper function which throws an error if a synthetic pointer is + invalid. */ + +static void +invalid_synthetic_pointer (void) +{ + error (_("access outside bounds of object " + "referenced via synthetic pointer")); +} + +/* Virtual method table for dwarf2_evaluate_loc_desc_full below. */ + +static const struct dwarf_expr_context_funcs dwarf_expr_ctx_funcs = +{ + dwarf_expr_read_reg, + dwarf_expr_read_mem, + dwarf_expr_frame_base, + dwarf_expr_frame_cfa, + dwarf_expr_frame_pc, + dwarf_expr_tls_address, + dwarf_expr_dwarf_call, + dwarf_expr_get_base_type, + dwarf_expr_push_dwarf_reg_entry_value, + dwarf_expr_get_addr_index +}; + /* Evaluate a location description, starting at DATA and with length - SIZE, to find the current location of variable of TYPE in the context - of FRAME. */ + SIZE, to find the current location of variable of TYPE in the + context of FRAME. BYTE_OFFSET is applied after the contents are + computed. */ static struct value * -dwarf2_evaluate_loc_desc (struct type *type, struct frame_info *frame, - const gdb_byte *data, unsigned short size, - struct dwarf2_per_cu_data *per_cu) +dwarf2_evaluate_loc_desc_full (struct type *type, struct frame_info *frame, + const gdb_byte *data, size_t size, + struct dwarf2_per_cu_data *per_cu, + LONGEST byte_offset) { struct value *retval; struct dwarf_expr_baton baton; struct dwarf_expr_context *ctx; - struct cleanup *old_chain; + struct cleanup *old_chain, *value_chain; + struct objfile *objfile = dwarf2_per_cu_objfile (per_cu); + volatile struct gdb_exception ex; + + if (byte_offset < 0) + invalid_synthetic_pointer (); if (size == 0) - { - retval = allocate_value (type); - VALUE_LVAL (retval) = not_lval; - set_value_optimized_out (retval, 1); - return retval; - } + return allocate_optimized_out_value (type); baton.frame = frame; - baton.objfile = dwarf2_per_cu_objfile (per_cu); + baton.per_cu = per_cu; ctx = new_dwarf_expr_context (); old_chain = make_cleanup_free_dwarf_expr_context (ctx); + value_chain = make_cleanup_value_free_to_mark (value_mark ()); - ctx->gdbarch = get_objfile_arch (baton.objfile); + ctx->gdbarch = get_objfile_arch (objfile); ctx->addr_size = dwarf2_per_cu_addr_size (per_cu); + ctx->ref_addr_size = dwarf2_per_cu_ref_addr_size (per_cu); + ctx->offset = dwarf2_per_cu_text_offset (per_cu); ctx->baton = &baton; - ctx->read_reg = dwarf_expr_read_reg; - ctx->read_mem = dwarf_expr_read_mem; - ctx->get_frame_base = dwarf_expr_frame_base; - ctx->get_frame_cfa = dwarf_expr_frame_cfa; - ctx->get_tls_address = dwarf_expr_tls_address; + ctx->funcs = &dwarf_expr_ctx_funcs; + + TRY_CATCH (ex, RETURN_MASK_ERROR) + { + dwarf_expr_eval (ctx, data, size); + } + if (ex.reason < 0) + { + if (ex.error == NOT_AVAILABLE_ERROR) + { + do_cleanups (old_chain); + retval = allocate_value (type); + mark_value_bytes_unavailable (retval, 0, TYPE_LENGTH (type)); + return retval; + } + else if (ex.error == NO_ENTRY_VALUE_ERROR) + { + if (entry_values_debug) + exception_print (gdb_stdout, ex); + do_cleanups (old_chain); + return allocate_optimized_out_value (type); + } + else + throw_exception (ex); + } - dwarf_expr_eval (ctx, data, size); if (ctx->num_pieces > 0) { struct piece_closure *c; struct frame_id frame_id = get_frame_id (frame); + ULONGEST bit_size = 0; + int i; - c = allocate_piece_closure (ctx->num_pieces, ctx->pieces, + for (i = 0; i < ctx->num_pieces; ++i) + bit_size += ctx->pieces[i].size; + if (8 * (byte_offset + TYPE_LENGTH (type)) > bit_size) + invalid_synthetic_pointer (); + + c = allocate_piece_closure (per_cu, ctx->num_pieces, ctx->pieces, ctx->addr_size); + /* We must clean up the value chain after creating the piece + closure but before allocating the result. */ + do_cleanups (value_chain); retval = allocate_computed_value (type, &pieced_value_funcs, c); VALUE_FRAME_ID (retval) = frame_id; + set_value_offset (retval, byte_offset); } else { @@ -822,9 +2194,12 @@ dwarf2_evaluate_loc_desc (struct type *type, struct frame_info *frame, case DWARF_VALUE_REGISTER: { struct gdbarch *arch = get_frame_arch (frame); - CORE_ADDR dwarf_regnum = dwarf_expr_fetch (ctx, 0); + ULONGEST dwarf_regnum = value_as_long (dwarf_expr_fetch (ctx, 0)); int gdb_regnum = gdbarch_dwarf2_reg_to_regnum (arch, dwarf_regnum); + if (byte_offset != 0) + error (_("cannot use offset on synthetic pointer to register")); + do_cleanups (value_chain); if (gdb_regnum != -1) retval = value_from_register (type, gdb_regnum, frame); else @@ -835,50 +2210,91 @@ dwarf2_evaluate_loc_desc (struct type *type, struct frame_info *frame, case DWARF_VALUE_MEMORY: { - CORE_ADDR address = dwarf_expr_fetch (ctx, 0); + CORE_ADDR address = dwarf_expr_fetch_address (ctx, 0); int in_stack_memory = dwarf_expr_fetch_in_stack_memory (ctx, 0); - retval = allocate_value (type); + do_cleanups (value_chain); + retval = allocate_value_lazy (type); VALUE_LVAL (retval) = lval_memory; - set_value_lazy (retval, 1); if (in_stack_memory) set_value_stack (retval, 1); - set_value_address (retval, address); + set_value_address (retval, address + byte_offset); } break; case DWARF_VALUE_STACK: { - ULONGEST value = (ULONGEST) dwarf_expr_fetch (ctx, 0); - bfd_byte *contents; - size_t n = ctx->addr_size; + struct value *value = dwarf_expr_fetch (ctx, 0); + gdb_byte *contents; + const gdb_byte *val_bytes; + size_t n = TYPE_LENGTH (value_type (value)); + + if (byte_offset + TYPE_LENGTH (type) > n) + invalid_synthetic_pointer (); + + val_bytes = value_contents_all (value); + val_bytes += byte_offset; + n -= byte_offset; + + /* Preserve VALUE because we are going to free values back + to the mark, but we still need the value contents + below. */ + value_incref (value); + do_cleanups (value_chain); + make_cleanup_value_free (value); retval = allocate_value (type); contents = value_contents_raw (retval); if (n > TYPE_LENGTH (type)) - n = TYPE_LENGTH (type); - store_unsigned_integer (contents, n, - gdbarch_byte_order (ctx->gdbarch), - value); + { + struct gdbarch *objfile_gdbarch = get_objfile_arch (objfile); + + if (gdbarch_byte_order (objfile_gdbarch) == BFD_ENDIAN_BIG) + val_bytes += n - TYPE_LENGTH (type); + n = TYPE_LENGTH (type); + } + memcpy (contents, val_bytes, n); } break; case DWARF_VALUE_LITERAL: { bfd_byte *contents; + const bfd_byte *ldata; size_t n = ctx->len; + if (byte_offset + TYPE_LENGTH (type) > n) + invalid_synthetic_pointer (); + + do_cleanups (value_chain); retval = allocate_value (type); contents = value_contents_raw (retval); + + ldata = ctx->data + byte_offset; + n -= byte_offset; + if (n > TYPE_LENGTH (type)) - n = TYPE_LENGTH (type); - memcpy (contents, ctx->data, n); + { + struct gdbarch *objfile_gdbarch = get_objfile_arch (objfile); + + if (gdbarch_byte_order (objfile_gdbarch) == BFD_ENDIAN_BIG) + ldata += n - TYPE_LENGTH (type); + n = TYPE_LENGTH (type); + } + memcpy (contents, ldata, n); } break; + case DWARF_VALUE_OPTIMIZED_OUT: + do_cleanups (value_chain); + retval = allocate_optimized_out_value (type); + break; + + /* DWARF_VALUE_IMPLICIT_POINTER was converted to a pieced + operation by execute_stack_op. */ + case DWARF_VALUE_IMPLICIT_POINTER: /* DWARF_VALUE_OPTIMIZED_OUT can't occur in this context -- it can only be encountered when making a piece. */ - case DWARF_VALUE_OPTIMIZED_OUT: default: internal_error (__FILE__, __LINE__, _("invalid location type")); } @@ -890,12 +2306,25 @@ dwarf2_evaluate_loc_desc (struct type *type, struct frame_info *frame, return retval; } + +/* The exported interface to dwarf2_evaluate_loc_desc_full; it always + passes 0 as the byte_offset. */ + +struct value * +dwarf2_evaluate_loc_desc (struct type *type, struct frame_info *frame, + const gdb_byte *data, size_t size, + struct dwarf2_per_cu_data *per_cu) +{ + return dwarf2_evaluate_loc_desc_full (type, frame, data, size, per_cu, 0); +} + /* Helper functions and baton for dwarf2_loc_desc_needs_frame. */ struct needs_frame_baton { int needs_frame; + struct dwarf2_per_cu_data *per_cu; }; /* Reads from registers do require a frame. */ @@ -949,31 +2378,83 @@ needs_frame_tls_address (void *baton, CORE_ADDR offset) return 1; } +/* Helper interface of per_cu_dwarf_call for dwarf2_loc_desc_needs_frame. */ + +static void +needs_frame_dwarf_call (struct dwarf_expr_context *ctx, cu_offset die_offset) +{ + struct needs_frame_baton *nf_baton = ctx->baton; + + per_cu_dwarf_call (ctx, die_offset, nf_baton->per_cu, + ctx->funcs->get_frame_pc, ctx->baton); +} + +/* DW_OP_GNU_entry_value accesses require a caller, therefore a frame. */ + +static void +needs_dwarf_reg_entry_value (struct dwarf_expr_context *ctx, + enum call_site_parameter_kind kind, + union call_site_parameter_u kind_u, int deref_size) +{ + struct needs_frame_baton *nf_baton = ctx->baton; + + nf_baton->needs_frame = 1; + + /* The expression may require some stub values on DWARF stack. */ + dwarf_expr_push_address (ctx, 0, 0); +} + +/* DW_OP_GNU_addr_index doesn't require a frame. */ + +static CORE_ADDR +needs_get_addr_index (void *baton, unsigned int index) +{ + /* Nothing to do. */ + return 1; +} + +/* Virtual method table for dwarf2_loc_desc_needs_frame below. */ + +static const struct dwarf_expr_context_funcs needs_frame_ctx_funcs = +{ + needs_frame_read_reg, + needs_frame_read_mem, + needs_frame_frame_base, + needs_frame_frame_cfa, + needs_frame_frame_cfa, /* get_frame_pc */ + needs_frame_tls_address, + needs_frame_dwarf_call, + NULL, /* get_base_type */ + needs_dwarf_reg_entry_value, + needs_get_addr_index +}; + /* Return non-zero iff the location expression at DATA (length SIZE) requires a frame to evaluate. */ static int -dwarf2_loc_desc_needs_frame (const gdb_byte *data, unsigned short size, +dwarf2_loc_desc_needs_frame (const gdb_byte *data, size_t size, struct dwarf2_per_cu_data *per_cu) { struct needs_frame_baton baton; struct dwarf_expr_context *ctx; int in_reg; struct cleanup *old_chain; + struct objfile *objfile = dwarf2_per_cu_objfile (per_cu); baton.needs_frame = 0; + baton.per_cu = per_cu; ctx = new_dwarf_expr_context (); old_chain = make_cleanup_free_dwarf_expr_context (ctx); + make_cleanup_value_free_to_mark (value_mark ()); - ctx->gdbarch = get_objfile_arch (dwarf2_per_cu_objfile (per_cu)); + ctx->gdbarch = get_objfile_arch (objfile); ctx->addr_size = dwarf2_per_cu_addr_size (per_cu); + ctx->ref_addr_size = dwarf2_per_cu_ref_addr_size (per_cu); + ctx->offset = dwarf2_per_cu_text_offset (per_cu); ctx->baton = &baton; - ctx->read_reg = needs_frame_read_reg; - ctx->read_mem = needs_frame_read_mem; - ctx->get_frame_base = needs_frame_frame_base; - ctx->get_frame_cfa = needs_frame_frame_cfa; - ctx->get_tls_address = needs_frame_tls_address; + ctx->funcs = &needs_frame_ctx_funcs; dwarf_expr_eval (ctx, data, size); @@ -995,266 +2476,753 @@ dwarf2_loc_desc_needs_frame (const gdb_byte *data, unsigned short size, return baton.needs_frame || in_reg; } -/* This struct keeps track of the pieces that make up a multi-location - object, for use in agent expression generation. It is - superficially similar to struct dwarf_expr_piece, but - dwarf_expr_piece is designed for use in immediate evaluation, and - does not, for example, have a way to record both base register and - offset. */ +/* A helper function that throws an unimplemented error mentioning a + given DWARF operator. */ -struct axs_var_loc +static void +unimplemented (unsigned int op) { - /* Memory vs register, etc */ - enum axs_lvalue_kind kind; + const char *name = get_DW_OP_name (op); + + if (name) + error (_("DWARF operator %s cannot be translated to an agent expression"), + name); + else + error (_("Unknown DWARF operator 0x%02x cannot be translated " + "to an agent expression"), + op); +} - /* If non-zero, number of bytes in this fragment */ - unsigned bytes; +/* A helper function to convert a DWARF register to an arch register. + ARCH is the architecture. + DWARF_REG is the register. + This will throw an exception if the DWARF register cannot be + translated to an architecture register. */ - /* (GDB-numbered) reg, or base reg if >= 0 */ - int reg; +static int +translate_register (struct gdbarch *arch, int dwarf_reg) +{ + int reg = gdbarch_dwarf2_reg_to_regnum (arch, dwarf_reg); + if (reg == -1) + error (_("Unable to access DWARF register number %d"), dwarf_reg); + return reg; +} - /* offset from reg */ - LONGEST offset; -}; +/* A helper function that emits an access to memory. ARCH is the + target architecture. EXPR is the expression which we are building. + NBITS is the number of bits we want to read. This emits the + opcodes needed to read the memory and then extract the desired + bits. */ -static const gdb_byte * -dwarf2_tracepoint_var_loc (struct symbol *symbol, - struct agent_expr *ax, - struct axs_var_loc *loc, - struct gdbarch *gdbarch, - const gdb_byte *data, const gdb_byte *end) +static void +access_memory (struct gdbarch *arch, struct agent_expr *expr, ULONGEST nbits) { - if (data[0] >= DW_OP_reg0 && data[0] <= DW_OP_reg31) + ULONGEST nbytes = (nbits + 7) / 8; + + gdb_assert (nbits > 0 && nbits <= sizeof (LONGEST)); + + if (trace_kludge) + ax_trace_quick (expr, nbytes); + + if (nbits <= 8) + ax_simple (expr, aop_ref8); + else if (nbits <= 16) + ax_simple (expr, aop_ref16); + else if (nbits <= 32) + ax_simple (expr, aop_ref32); + else + ax_simple (expr, aop_ref64); + + /* If we read exactly the number of bytes we wanted, we're done. */ + if (8 * nbytes == nbits) + return; + + if (gdbarch_bits_big_endian (arch)) { - loc->kind = axs_lvalue_register; - loc->reg = gdbarch_dwarf2_reg_to_regnum (gdbarch, data[0] - DW_OP_reg0); - data += 1; + /* On a bits-big-endian machine, we want the high-order + NBITS. */ + ax_const_l (expr, 8 * nbytes - nbits); + ax_simple (expr, aop_rsh_unsigned); } - else if (data[0] == DW_OP_regx) + else { - ULONGEST reg; - - data = read_uleb128 (data + 1, end, ®); - loc->kind = axs_lvalue_register; - loc->reg = gdbarch_dwarf2_reg_to_regnum (gdbarch, reg); + /* On a bits-little-endian box, we want the low-order NBITS. */ + ax_zero_ext (expr, nbits); } - else if (data[0] == DW_OP_fbreg) - { - struct block *b; - struct symbol *framefunc; - int frame_reg = 0; - LONGEST frame_offset; - const gdb_byte *base_data; - size_t base_size; - LONGEST base_offset = 0; +} - b = block_for_pc (ax->scope); +/* A helper function to return the frame's PC. */ - if (!b) - error (_("No block found for address")); +static CORE_ADDR +get_ax_pc (void *baton) +{ + struct agent_expr *expr = baton; - framefunc = block_linkage_function (b); + return expr->scope; +} - if (!framefunc) - error (_("No function found for block")); +/* Compile a DWARF location expression to an agent expression. + + EXPR is the agent expression we are building. + LOC is the agent value we modify. + ARCH is the architecture. + ADDR_SIZE is the size of addresses, in bytes. + OP_PTR is the start of the location expression. + OP_END is one past the last byte of the location expression. + + This will throw an exception for various kinds of errors -- for + example, if the expression cannot be compiled, or if the expression + is invalid. */ + +void +dwarf2_compile_expr_to_ax (struct agent_expr *expr, struct axs_value *loc, + struct gdbarch *arch, unsigned int addr_size, + const gdb_byte *op_ptr, const gdb_byte *op_end, + struct dwarf2_per_cu_data *per_cu) +{ + struct cleanup *cleanups; + int i, *offsets; + VEC(int) *dw_labels = NULL, *patches = NULL; + const gdb_byte * const base = op_ptr; + const gdb_byte *previous_piece = op_ptr; + enum bfd_endian byte_order = gdbarch_byte_order (arch); + ULONGEST bits_collected = 0; + unsigned int addr_size_bits = 8 * addr_size; + int bits_big_endian = gdbarch_bits_big_endian (arch); - dwarf_expr_frame_base_1 (framefunc, ax->scope, - &base_data, &base_size); + offsets = xmalloc ((op_end - op_ptr) * sizeof (int)); + cleanups = make_cleanup (xfree, offsets); - if (base_data[0] >= DW_OP_breg0 && base_data[0] <= DW_OP_breg31) - { - const gdb_byte *buf_end; + for (i = 0; i < op_end - op_ptr; ++i) + offsets[i] = -1; - frame_reg = base_data[0] - DW_OP_breg0; - buf_end = read_sleb128 (base_data + 1, - base_data + base_size, &base_offset); - if (buf_end != base_data + base_size) - error (_("Unexpected opcode after DW_OP_breg%u for symbol \"%s\"."), - frame_reg, SYMBOL_PRINT_NAME (symbol)); - } - else if (base_data[0] >= DW_OP_reg0 && base_data[0] <= DW_OP_reg31) - { - /* The frame base is just the register, with no offset. */ - frame_reg = base_data[0] - DW_OP_reg0; - base_offset = 0; - } - else - { - /* We don't know what to do with the frame base expression, - so we can't trace this variable; give up. */ - error (_("Cannot generate expression to collect symbol \"%s\"; DWARF 2 encoding not handled, first opcode in base data is 0x%x."), - SYMBOL_PRINT_NAME (symbol), base_data[0]); - } + make_cleanup (VEC_cleanup (int), &dw_labels); + make_cleanup (VEC_cleanup (int), &patches); - data = read_sleb128 (data + 1, end, &frame_offset); + /* By default we are making an address. */ + loc->kind = axs_lvalue_memory; - loc->kind = axs_lvalue_memory; - loc->reg = gdbarch_dwarf2_reg_to_regnum (gdbarch, frame_reg); - loc->offset = base_offset + frame_offset; - } - else if (data[0] >= DW_OP_breg0 && data[0] <= DW_OP_breg31) + while (op_ptr < op_end) { - unsigned int reg; - LONGEST offset; + enum dwarf_location_atom op = *op_ptr; + uint64_t uoffset, reg; + int64_t offset; + int i; + + offsets[op_ptr - base] = expr->len; + ++op_ptr; + + /* Our basic approach to code generation is to map DWARF + operations directly to AX operations. However, there are + some differences. + + First, DWARF works on address-sized units, but AX always uses + LONGEST. For most operations we simply ignore this + difference; instead we generate sign extensions as needed + before division and comparison operations. It would be nice + to omit the sign extensions, but there is no way to determine + the size of the target's LONGEST. (This code uses the size + of the host LONGEST in some cases -- that is a bug but it is + difficult to fix.) + + Second, some DWARF operations cannot be translated to AX. + For these we simply fail. See + http://sourceware.org/bugzilla/show_bug.cgi?id=11662. */ + switch (op) + { + case DW_OP_lit0: + case DW_OP_lit1: + case DW_OP_lit2: + case DW_OP_lit3: + case DW_OP_lit4: + case DW_OP_lit5: + case DW_OP_lit6: + case DW_OP_lit7: + case DW_OP_lit8: + case DW_OP_lit9: + case DW_OP_lit10: + case DW_OP_lit11: + case DW_OP_lit12: + case DW_OP_lit13: + case DW_OP_lit14: + case DW_OP_lit15: + case DW_OP_lit16: + case DW_OP_lit17: + case DW_OP_lit18: + case DW_OP_lit19: + case DW_OP_lit20: + case DW_OP_lit21: + case DW_OP_lit22: + case DW_OP_lit23: + case DW_OP_lit24: + case DW_OP_lit25: + case DW_OP_lit26: + case DW_OP_lit27: + case DW_OP_lit28: + case DW_OP_lit29: + case DW_OP_lit30: + case DW_OP_lit31: + ax_const_l (expr, op - DW_OP_lit0); + break; - reg = data[0] - DW_OP_breg0; - data = read_sleb128 (data + 1, end, &offset); + case DW_OP_addr: + uoffset = extract_unsigned_integer (op_ptr, addr_size, byte_order); + op_ptr += addr_size; + /* Some versions of GCC emit DW_OP_addr before + DW_OP_GNU_push_tls_address. In this case the value is an + index, not an address. We don't support things like + branching between the address and the TLS op. */ + if (op_ptr >= op_end || *op_ptr != DW_OP_GNU_push_tls_address) + uoffset += dwarf2_per_cu_text_offset (per_cu); + ax_const_l (expr, uoffset); + break; - loc->kind = axs_lvalue_memory; - loc->reg = gdbarch_dwarf2_reg_to_regnum (gdbarch, reg); - loc->offset = offset; - } - else - error (_("Unsupported DWARF opcode 0x%x in the location of \"%s\"."), - data[0], SYMBOL_PRINT_NAME (symbol)); - - return data; -} + case DW_OP_const1u: + ax_const_l (expr, extract_unsigned_integer (op_ptr, 1, byte_order)); + op_ptr += 1; + break; + case DW_OP_const1s: + ax_const_l (expr, extract_signed_integer (op_ptr, 1, byte_order)); + op_ptr += 1; + break; + case DW_OP_const2u: + ax_const_l (expr, extract_unsigned_integer (op_ptr, 2, byte_order)); + op_ptr += 2; + break; + case DW_OP_const2s: + ax_const_l (expr, extract_signed_integer (op_ptr, 2, byte_order)); + op_ptr += 2; + break; + case DW_OP_const4u: + ax_const_l (expr, extract_unsigned_integer (op_ptr, 4, byte_order)); + op_ptr += 4; + break; + case DW_OP_const4s: + ax_const_l (expr, extract_signed_integer (op_ptr, 4, byte_order)); + op_ptr += 4; + break; + case DW_OP_const8u: + ax_const_l (expr, extract_unsigned_integer (op_ptr, 8, byte_order)); + op_ptr += 8; + break; + case DW_OP_const8s: + ax_const_l (expr, extract_signed_integer (op_ptr, 8, byte_order)); + op_ptr += 8; + break; + case DW_OP_constu: + op_ptr = safe_read_uleb128 (op_ptr, op_end, &uoffset); + ax_const_l (expr, uoffset); + break; + case DW_OP_consts: + op_ptr = safe_read_sleb128 (op_ptr, op_end, &offset); + ax_const_l (expr, offset); + break; -/* Given the location of a piece, issue bytecodes that will access it. */ + case DW_OP_reg0: + case DW_OP_reg1: + case DW_OP_reg2: + case DW_OP_reg3: + case DW_OP_reg4: + case DW_OP_reg5: + case DW_OP_reg6: + case DW_OP_reg7: + case DW_OP_reg8: + case DW_OP_reg9: + case DW_OP_reg10: + case DW_OP_reg11: + case DW_OP_reg12: + case DW_OP_reg13: + case DW_OP_reg14: + case DW_OP_reg15: + case DW_OP_reg16: + case DW_OP_reg17: + case DW_OP_reg18: + case DW_OP_reg19: + case DW_OP_reg20: + case DW_OP_reg21: + case DW_OP_reg22: + case DW_OP_reg23: + case DW_OP_reg24: + case DW_OP_reg25: + case DW_OP_reg26: + case DW_OP_reg27: + case DW_OP_reg28: + case DW_OP_reg29: + case DW_OP_reg30: + case DW_OP_reg31: + dwarf_expr_require_composition (op_ptr, op_end, "DW_OP_regx"); + loc->u.reg = translate_register (arch, op - DW_OP_reg0); + loc->kind = axs_lvalue_register; + break; -static void -dwarf2_tracepoint_var_access (struct agent_expr *ax, - struct axs_value *value, - struct axs_var_loc *loc) -{ - value->kind = loc->kind; - - switch (loc->kind) - { - case axs_lvalue_register: - value->u.reg = loc->reg; - break; - - case axs_lvalue_memory: - ax_reg (ax, loc->reg); - if (loc->offset) - { - ax_const_l (ax, loc->offset); - ax_simple (ax, aop_add); - } - break; - - default: - internal_error (__FILE__, __LINE__, _("Unhandled value kind in dwarf2_tracepoint_var_access")); - } -} + case DW_OP_regx: + op_ptr = safe_read_uleb128 (op_ptr, op_end, ®); + dwarf_expr_require_composition (op_ptr, op_end, "DW_OP_regx"); + loc->u.reg = translate_register (arch, reg); + loc->kind = axs_lvalue_register; + break; + + case DW_OP_implicit_value: + { + uint64_t len; + + op_ptr = safe_read_uleb128 (op_ptr, op_end, &len); + if (op_ptr + len > op_end) + error (_("DW_OP_implicit_value: too few bytes available.")); + if (len > sizeof (ULONGEST)) + error (_("Cannot translate DW_OP_implicit_value of %d bytes"), + (int) len); + + ax_const_l (expr, extract_unsigned_integer (op_ptr, len, + byte_order)); + op_ptr += len; + dwarf_expr_require_composition (op_ptr, op_end, + "DW_OP_implicit_value"); + + loc->kind = axs_rvalue; + } + break; + + case DW_OP_stack_value: + dwarf_expr_require_composition (op_ptr, op_end, "DW_OP_stack_value"); + loc->kind = axs_rvalue; + break; + + case DW_OP_breg0: + case DW_OP_breg1: + case DW_OP_breg2: + case DW_OP_breg3: + case DW_OP_breg4: + case DW_OP_breg5: + case DW_OP_breg6: + case DW_OP_breg7: + case DW_OP_breg8: + case DW_OP_breg9: + case DW_OP_breg10: + case DW_OP_breg11: + case DW_OP_breg12: + case DW_OP_breg13: + case DW_OP_breg14: + case DW_OP_breg15: + case DW_OP_breg16: + case DW_OP_breg17: + case DW_OP_breg18: + case DW_OP_breg19: + case DW_OP_breg20: + case DW_OP_breg21: + case DW_OP_breg22: + case DW_OP_breg23: + case DW_OP_breg24: + case DW_OP_breg25: + case DW_OP_breg26: + case DW_OP_breg27: + case DW_OP_breg28: + case DW_OP_breg29: + case DW_OP_breg30: + case DW_OP_breg31: + op_ptr = safe_read_sleb128 (op_ptr, op_end, &offset); + i = translate_register (arch, op - DW_OP_breg0); + ax_reg (expr, i); + if (offset != 0) + { + ax_const_l (expr, offset); + ax_simple (expr, aop_add); + } + break; + case DW_OP_bregx: + { + op_ptr = safe_read_uleb128 (op_ptr, op_end, ®); + op_ptr = safe_read_sleb128 (op_ptr, op_end, &offset); + i = translate_register (arch, reg); + ax_reg (expr, i); + if (offset != 0) + { + ax_const_l (expr, offset); + ax_simple (expr, aop_add); + } + } + break; + case DW_OP_fbreg: + { + const gdb_byte *datastart; + size_t datalen; + struct block *b; + struct symbol *framefunc; + LONGEST base_offset = 0; + + b = block_for_pc (expr->scope); + + if (!b) + error (_("No block found for address")); + + framefunc = block_linkage_function (b); + + if (!framefunc) + error (_("No function found for block")); + + dwarf_expr_frame_base_1 (framefunc, expr->scope, + &datastart, &datalen); + + op_ptr = safe_read_sleb128 (op_ptr, op_end, &offset); + dwarf2_compile_expr_to_ax (expr, loc, arch, addr_size, datastart, + datastart + datalen, per_cu); + + if (offset != 0) + { + ax_const_l (expr, offset); + ax_simple (expr, aop_add); + } + + loc->kind = axs_lvalue_memory; + } + break; + + case DW_OP_dup: + ax_simple (expr, aop_dup); + break; + + case DW_OP_drop: + ax_simple (expr, aop_pop); + break; + + case DW_OP_pick: + offset = *op_ptr++; + ax_pick (expr, offset); + break; + + case DW_OP_swap: + ax_simple (expr, aop_swap); + break; + + case DW_OP_over: + ax_pick (expr, 1); + break; + + case DW_OP_rot: + ax_simple (expr, aop_rot); + break; + + case DW_OP_deref: + case DW_OP_deref_size: + { + int size; + + if (op == DW_OP_deref_size) + size = *op_ptr++; + else + size = addr_size; + + switch (size) + { + case 8: + ax_simple (expr, aop_ref8); + break; + case 16: + ax_simple (expr, aop_ref16); + break; + case 32: + ax_simple (expr, aop_ref32); + break; + case 64: + ax_simple (expr, aop_ref64); + break; + default: + /* Note that get_DW_OP_name will never return + NULL here. */ + error (_("Unsupported size %d in %s"), + size, get_DW_OP_name (op)); + } + } + break; + + case DW_OP_abs: + /* Sign extend the operand. */ + ax_ext (expr, addr_size_bits); + ax_simple (expr, aop_dup); + ax_const_l (expr, 0); + ax_simple (expr, aop_less_signed); + ax_simple (expr, aop_log_not); + i = ax_goto (expr, aop_if_goto); + /* We have to emit 0 - X. */ + ax_const_l (expr, 0); + ax_simple (expr, aop_swap); + ax_simple (expr, aop_sub); + ax_label (expr, i, expr->len); + break; + + case DW_OP_neg: + /* No need to sign extend here. */ + ax_const_l (expr, 0); + ax_simple (expr, aop_swap); + ax_simple (expr, aop_sub); + break; + + case DW_OP_not: + /* Sign extend the operand. */ + ax_ext (expr, addr_size_bits); + ax_simple (expr, aop_bit_not); + break; + + case DW_OP_plus_uconst: + op_ptr = safe_read_uleb128 (op_ptr, op_end, ®); + /* It would be really weird to emit `DW_OP_plus_uconst 0', + but we micro-optimize anyhow. */ + if (reg != 0) + { + ax_const_l (expr, reg); + ax_simple (expr, aop_add); + } + break; + + case DW_OP_and: + ax_simple (expr, aop_bit_and); + break; + + case DW_OP_div: + /* Sign extend the operands. */ + ax_ext (expr, addr_size_bits); + ax_simple (expr, aop_swap); + ax_ext (expr, addr_size_bits); + ax_simple (expr, aop_swap); + ax_simple (expr, aop_div_signed); + break; + + case DW_OP_minus: + ax_simple (expr, aop_sub); + break; + + case DW_OP_mod: + ax_simple (expr, aop_rem_unsigned); + break; + + case DW_OP_mul: + ax_simple (expr, aop_mul); + break; + + case DW_OP_or: + ax_simple (expr, aop_bit_or); + break; + + case DW_OP_plus: + ax_simple (expr, aop_add); + break; + + case DW_OP_shl: + ax_simple (expr, aop_lsh); + break; + + case DW_OP_shr: + ax_simple (expr, aop_rsh_unsigned); + break; + + case DW_OP_shra: + ax_simple (expr, aop_rsh_signed); + break; + + case DW_OP_xor: + ax_simple (expr, aop_bit_xor); + break; + + case DW_OP_le: + /* Sign extend the operands. */ + ax_ext (expr, addr_size_bits); + ax_simple (expr, aop_swap); + ax_ext (expr, addr_size_bits); + /* Note no swap here: A <= B is !(B < A). */ + ax_simple (expr, aop_less_signed); + ax_simple (expr, aop_log_not); + break; + + case DW_OP_ge: + /* Sign extend the operands. */ + ax_ext (expr, addr_size_bits); + ax_simple (expr, aop_swap); + ax_ext (expr, addr_size_bits); + ax_simple (expr, aop_swap); + /* A >= B is !(A < B). */ + ax_simple (expr, aop_less_signed); + ax_simple (expr, aop_log_not); + break; + + case DW_OP_eq: + /* Sign extend the operands. */ + ax_ext (expr, addr_size_bits); + ax_simple (expr, aop_swap); + ax_ext (expr, addr_size_bits); + /* No need for a second swap here. */ + ax_simple (expr, aop_equal); + break; + + case DW_OP_lt: + /* Sign extend the operands. */ + ax_ext (expr, addr_size_bits); + ax_simple (expr, aop_swap); + ax_ext (expr, addr_size_bits); + ax_simple (expr, aop_swap); + ax_simple (expr, aop_less_signed); + break; + + case DW_OP_gt: + /* Sign extend the operands. */ + ax_ext (expr, addr_size_bits); + ax_simple (expr, aop_swap); + ax_ext (expr, addr_size_bits); + /* Note no swap here: A > B is B < A. */ + ax_simple (expr, aop_less_signed); + break; + + case DW_OP_ne: + /* Sign extend the operands. */ + ax_ext (expr, addr_size_bits); + ax_simple (expr, aop_swap); + ax_ext (expr, addr_size_bits); + /* No need for a swap here. */ + ax_simple (expr, aop_equal); + ax_simple (expr, aop_log_not); + break; + + case DW_OP_call_frame_cfa: + dwarf2_compile_cfa_to_ax (expr, loc, arch, expr->scope, per_cu); + loc->kind = axs_lvalue_memory; + break; -static void -dwarf2_tracepoint_var_ref (struct symbol *symbol, struct gdbarch *gdbarch, - struct agent_expr *ax, struct axs_value *value, - const gdb_byte *data, int size) -{ - const gdb_byte *end = data + size; - enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); - /* In practice, a variable is not going to be spread across - dozens of registers or memory locations. If someone comes up - with a real-world example, revisit this. */ -#define MAX_FRAGS 16 - struct axs_var_loc fragments[MAX_FRAGS]; - int nfrags = 0, frag; - int length = 0; - int piece_ok = 0; - int bad = 0; - int first = 1; - - if (!data || size == 0) - { - value->optimized_out = 1; - return; - } + case DW_OP_GNU_push_tls_address: + unimplemented (op); + break; - while (data < end) - { - if (!piece_ok) - { - if (nfrags == MAX_FRAGS) - error (_("Too many pieces in location for \"%s\"."), - SYMBOL_PRINT_NAME (symbol)); - - fragments[nfrags].bytes = 0; - data = dwarf2_tracepoint_var_loc (symbol, ax, &fragments[nfrags], - gdbarch, data, end); - nfrags++; - piece_ok = 1; - } - else if (data[0] == DW_OP_piece) - { - ULONGEST bytes; - - data = read_uleb128 (data + 1, end, &bytes); - /* Only deal with 4 byte fragments for now. */ - if (bytes != 4) - error (_("DW_OP_piece %s not supported in location for \"%s\"."), - pulongest (bytes), SYMBOL_PRINT_NAME (symbol)); - fragments[nfrags - 1].bytes = bytes; - length += bytes; - piece_ok = 0; - } - else - { - bad = 1; + case DW_OP_skip: + offset = extract_signed_integer (op_ptr, 2, byte_order); + op_ptr += 2; + i = ax_goto (expr, aop_goto); + VEC_safe_push (int, dw_labels, op_ptr + offset - base); + VEC_safe_push (int, patches, i); break; - } - } - if (bad || data > end) - error (_("Corrupted DWARF expression for \"%s\"."), - SYMBOL_PRINT_NAME (symbol)); + case DW_OP_bra: + offset = extract_signed_integer (op_ptr, 2, byte_order); + op_ptr += 2; + /* Zero extend the operand. */ + ax_zero_ext (expr, addr_size_bits); + i = ax_goto (expr, aop_if_goto); + VEC_safe_push (int, dw_labels, op_ptr + offset - base); + VEC_safe_push (int, patches, i); + break; - /* If single expression, no pieces, convert to external format. */ - if (length == 0) - { - dwarf2_tracepoint_var_access (ax, value, &fragments[0]); - return; - } + case DW_OP_nop: + break; - if (length != TYPE_LENGTH (value->type)) - error (_("Inconsistent piece information for \"%s\"."), - SYMBOL_PRINT_NAME (symbol)); + case DW_OP_piece: + case DW_OP_bit_piece: + { + uint64_t size, offset; - /* Emit bytecodes to assemble the pieces into a single stack entry. */ + if (op_ptr - 1 == previous_piece) + error (_("Cannot translate empty pieces to agent expressions")); + previous_piece = op_ptr - 1; - for ((frag = (byte_order == BFD_ENDIAN_BIG ? 0 : nfrags - 1)); - nfrags--; - (frag += (byte_order == BFD_ENDIAN_BIG ? 1 : -1))) - { - if (!first) - { - /* shift the previous fragment up 32 bits */ - ax_const_l (ax, 32); - ax_simple (ax, aop_lsh); - } + op_ptr = safe_read_uleb128 (op_ptr, op_end, &size); + if (op == DW_OP_piece) + { + size *= 8; + offset = 0; + } + else + op_ptr = safe_read_uleb128 (op_ptr, op_end, &offset); - dwarf2_tracepoint_var_access (ax, value, &fragments[frag]); + if (bits_collected + size > 8 * sizeof (LONGEST)) + error (_("Expression pieces exceed word size")); - switch (value->kind) - { - case axs_lvalue_register: - ax_reg (ax, value->u.reg); + /* Access the bits. */ + switch (loc->kind) + { + case axs_lvalue_register: + ax_reg (expr, loc->u.reg); + break; + + case axs_lvalue_memory: + /* Offset the pointer, if needed. */ + if (offset > 8) + { + ax_const_l (expr, offset / 8); + ax_simple (expr, aop_add); + offset %= 8; + } + access_memory (arch, expr, size); + break; + } + + /* For a bits-big-endian target, shift up what we already + have. For a bits-little-endian target, shift up the + new data. Note that there is a potential bug here if + the DWARF expression leaves multiple values on the + stack. */ + if (bits_collected > 0) + { + if (bits_big_endian) + { + ax_simple (expr, aop_swap); + ax_const_l (expr, size); + ax_simple (expr, aop_lsh); + /* We don't need a second swap here, because + aop_bit_or is symmetric. */ + } + else + { + ax_const_l (expr, size); + ax_simple (expr, aop_lsh); + } + ax_simple (expr, aop_bit_or); + } + + bits_collected += size; + loc->kind = axs_rvalue; + } break; - case axs_lvalue_memory: + case DW_OP_GNU_uninit: + unimplemented (op); + + case DW_OP_call2: + case DW_OP_call4: { - extern int trace_kludge; /* Ugh. */ + struct dwarf2_locexpr_baton block; + int size = (op == DW_OP_call2 ? 2 : 4); + cu_offset offset; - gdb_assert (fragments[frag].bytes == 4); - if (trace_kludge) - ax_trace_quick (ax, 4); - ax_simple (ax, aop_ref32); + uoffset = extract_unsigned_integer (op_ptr, size, byte_order); + op_ptr += size; + + offset.cu_off = uoffset; + block = dwarf2_fetch_die_location_block (offset, per_cu, + get_ax_pc, expr); + + /* DW_OP_call_ref is currently not supported. */ + gdb_assert (block.per_cu == per_cu); + + dwarf2_compile_expr_to_ax (expr, loc, arch, addr_size, + block.data, block.data + block.size, + per_cu); } break; - } - if (!first) - { - /* or the new fragment into the previous */ - ax_zero_ext (ax, 32); - ax_simple (ax, aop_bit_or); + case DW_OP_call_ref: + unimplemented (op); + + default: + unimplemented (op); } - first = 0; } - value->kind = axs_rvalue; + + /* Patch all the branches we emitted. */ + for (i = 0; i < VEC_length (int, patches); ++i) + { + int targ = offsets[VEC_index (int, dw_labels, i)]; + if (targ == -1) + internal_error (__FILE__, __LINE__, _("invalid label")); + ax_label (expr, VEC_index (int, patches, i), targ); + } + + do_cleanups (cleanups); } @@ -1272,6 +3240,19 @@ locexpr_read_variable (struct symbol *symbol, struct frame_info *frame) return val; } +/* Return the value of SYMBOL in FRAME at (callee) FRAME's function + entry. SYMBOL should be a function parameter, otherwise NO_ENTRY_VALUE_ERROR + will be thrown. */ + +static struct value * +locexpr_read_variable_at_entry (struct symbol *symbol, struct frame_info *frame) +{ + struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol); + + return value_of_dwarf_block_entry (SYMBOL_TYPE (symbol), frame, dlbaton->data, + dlbaton->size); +} + /* Return non-zero iff we need a frame to evaluate SYMBOL. */ static int locexpr_read_needs_frame (struct symbol *symbol) @@ -1282,43 +3263,71 @@ locexpr_read_needs_frame (struct symbol *symbol) dlbaton->per_cu); } -/* Describe a single piece of a location, returning an updated - position in the bytecode sequence. */ +/* Return true if DATA points to the end of a piece. END is one past + the last byte in the expression. */ + +static int +piece_end_p (const gdb_byte *data, const gdb_byte *end) +{ + return data == end || data[0] == DW_OP_piece || data[0] == DW_OP_bit_piece; +} + +/* Helper for locexpr_describe_location_piece that finds the name of a + DWARF register. */ + +static const char * +locexpr_regname (struct gdbarch *gdbarch, int dwarf_regnum) +{ + int regnum; + + regnum = gdbarch_dwarf2_reg_to_regnum (gdbarch, dwarf_regnum); + return gdbarch_register_name (gdbarch, regnum); +} + +/* Nicely describe a single piece of a location, returning an updated + position in the bytecode sequence. This function cannot recognize + all locations; if a location is not recognized, it simply returns + DATA. If there is an error during reading, e.g. we run off the end + of the buffer, an error is thrown. */ static const gdb_byte * locexpr_describe_location_piece (struct symbol *symbol, struct ui_file *stream, CORE_ADDR addr, struct objfile *objfile, - const gdb_byte *data, int size, + struct dwarf2_per_cu_data *per_cu, + const gdb_byte *data, const gdb_byte *end, unsigned int addr_size) { struct gdbarch *gdbarch = get_objfile_arch (objfile); - int regno; + size_t leb128_size; if (data[0] >= DW_OP_reg0 && data[0] <= DW_OP_reg31) { - regno = gdbarch_dwarf2_reg_to_regnum (gdbarch, data[0] - DW_OP_reg0); fprintf_filtered (stream, _("a variable in $%s"), - gdbarch_register_name (gdbarch, regno)); + locexpr_regname (gdbarch, data[0] - DW_OP_reg0)); data += 1; } else if (data[0] == DW_OP_regx) { - ULONGEST reg; + uint64_t reg; - data = read_uleb128 (data + 1, data + size, ®); - regno = gdbarch_dwarf2_reg_to_regnum (gdbarch, reg); + data = safe_read_uleb128 (data + 1, end, ®); fprintf_filtered (stream, _("a variable in $%s"), - gdbarch_register_name (gdbarch, regno)); + locexpr_regname (gdbarch, reg)); } else if (data[0] == DW_OP_fbreg) { struct block *b; struct symbol *framefunc; int frame_reg = 0; - LONGEST frame_offset; - const gdb_byte *base_data; + int64_t frame_offset; + const gdb_byte *base_data, *new_data, *save_data = data; size_t base_size; - LONGEST base_offset = 0; + int64_t base_offset = 0; + + new_data = safe_read_sleb128 (data + 1, end, &frame_offset); + if (!piece_end_p (new_data, end)) + return data; + data = new_data; b = block_for_pc (addr); @@ -1339,10 +3348,11 @@ locexpr_describe_location_piece (struct symbol *symbol, struct ui_file *stream, const gdb_byte *buf_end; frame_reg = base_data[0] - DW_OP_breg0; - buf_end = read_sleb128 (base_data + 1, - base_data + base_size, &base_offset); + buf_end = safe_read_sleb128 (base_data + 1, base_data + base_size, + &base_offset); if (buf_end != base_data + base_size) - error (_("Unexpected opcode after DW_OP_breg%u for symbol \"%s\"."), + error (_("Unexpected opcode after " + "DW_OP_breg%u for symbol \"%s\"."), frame_reg, SYMBOL_PRINT_NAME (symbol)); } else if (base_data[0] >= DW_OP_reg0 && base_data[0] <= DW_OP_reg31) @@ -1355,32 +3365,25 @@ locexpr_describe_location_piece (struct symbol *symbol, struct ui_file *stream, { /* We don't know what to do with the frame base expression, so we can't trace this variable; give up. */ - error (_("Cannot describe location of symbol \"%s\"; " - "DWARF 2 encoding not handled, " - "first opcode in base data is 0x%x."), - SYMBOL_PRINT_NAME (symbol), base_data[0]); + return save_data; } - regno = gdbarch_dwarf2_reg_to_regnum (gdbarch, frame_reg); - - data = read_sleb128 (data + 1, data + size, &frame_offset); - - fprintf_filtered (stream, _("a variable at frame base reg $%s offset %s+%s"), - gdbarch_register_name (gdbarch, regno), + fprintf_filtered (stream, + _("a variable at frame base reg $%s offset %s+%s"), + locexpr_regname (gdbarch, frame_reg), plongest (base_offset), plongest (frame_offset)); } - else if (data[0] >= DW_OP_breg0 && data[0] <= DW_OP_breg31) + else if (data[0] >= DW_OP_breg0 && data[0] <= DW_OP_breg31 + && piece_end_p (data, end)) { - LONGEST offset; + int64_t offset; - regno = gdbarch_dwarf2_reg_to_regnum (gdbarch, data[0] - DW_OP_breg0); - - data = read_sleb128 (data + 1, data + size, &offset); + data = safe_read_sleb128 (data + 1, end, &offset); fprintf_filtered (stream, _("a variable at offset %s from base reg $%s"), plongest (offset), - gdbarch_register_name (gdbarch, regno)); + locexpr_regname (gdbarch, data[0] - DW_OP_breg0)); } /* The location expression for a TLS variable looks like this (on a @@ -1388,32 +3391,432 @@ locexpr_describe_location_piece (struct symbol *symbol, struct ui_file *stream, DW_AT_location : 10 byte block: 3 4 0 0 0 0 0 0 0 e0 (DW_OP_addr: 4; DW_OP_GNU_push_tls_address) - + 0x3 is the encoding for DW_OP_addr, which has an operand as long as the size of an address on the target machine (here is 8 - bytes). 0xe0 is the encoding for DW_OP_GNU_push_tls_address. + bytes). Note that more recent version of GCC emit DW_OP_const4u + or DW_OP_const8u, depending on address size, rather than + DW_OP_addr. 0xe0 is the encoding for DW_OP_GNU_push_tls_address. The operand represents the offset at which the variable is within the thread local storage. */ - else if (size > 1 - && data[size - 1] == DW_OP_GNU_push_tls_address - && data[0] == DW_OP_addr) + else if (data + 1 + addr_size < end + && (data[0] == DW_OP_addr + || (addr_size == 4 && data[0] == DW_OP_const4u) + || (addr_size == 8 && data[0] == DW_OP_const8u)) + && data[1 + addr_size] == DW_OP_GNU_push_tls_address + && piece_end_p (data + 2 + addr_size, end)) { - CORE_ADDR offset = dwarf2_read_address (gdbarch, - data + 1, - data + size - 1, - addr_size); + ULONGEST offset; + offset = extract_unsigned_integer (data + 1, addr_size, + gdbarch_byte_order (gdbarch)); fprintf_filtered (stream, - _("a thread-local variable at offset %s " + _("a thread-local variable at offset 0x%s " "in the thread-local storage for `%s'"), - paddress (gdbarch, offset), objfile->name); + phex_nz (offset, addr_size), objfile->name); data += 1 + addr_size + 1; } - else - fprintf_filtered (stream, - _("a variable with complex or multiple locations (DWARF2)")); + + /* With -gsplit-dwarf a TLS variable can also look like this: + DW_AT_location : 3 byte block: fc 4 e0 + (DW_OP_GNU_const_index: 4; + DW_OP_GNU_push_tls_address) */ + else if (data + 3 <= end + && data + 1 + (leb128_size = skip_leb128 (data + 1, end)) < end + && data[0] == DW_OP_GNU_const_index + && leb128_size > 0 + && data[1 + leb128_size] == DW_OP_GNU_push_tls_address + && piece_end_p (data + 2 + leb128_size, end)) + { + uint64_t offset; + + data = safe_read_uleb128 (data + 1, end, &offset); + offset = dwarf2_read_addr_index (per_cu, offset); + fprintf_filtered (stream, + _("a thread-local variable at offset 0x%s " + "in the thread-local storage for `%s'"), + phex_nz (offset, addr_size), objfile->name); + ++data; + } + + else if (data[0] >= DW_OP_lit0 + && data[0] <= DW_OP_lit31 + && data + 1 < end + && data[1] == DW_OP_stack_value) + { + fprintf_filtered (stream, _("the constant %d"), data[0] - DW_OP_lit0); + data += 2; + } + + return data; +} + +/* Disassemble an expression, stopping at the end of a piece or at the + end of the expression. Returns a pointer to the next unread byte + in the input expression. If ALL is nonzero, then this function + will keep going until it reaches the end of the expression. + If there is an error during reading, e.g. we run off the end + of the buffer, an error is thrown. */ + +static const gdb_byte * +disassemble_dwarf_expression (struct ui_file *stream, + struct gdbarch *arch, unsigned int addr_size, + int offset_size, const gdb_byte *start, + const gdb_byte *data, const gdb_byte *end, + int indent, int all, + struct dwarf2_per_cu_data *per_cu) +{ + while (data < end + && (all + || (data[0] != DW_OP_piece && data[0] != DW_OP_bit_piece))) + { + enum dwarf_location_atom op = *data++; + uint64_t ul; + int64_t l; + const char *name; + + name = get_DW_OP_name (op); + + if (!name) + error (_("Unrecognized DWARF opcode 0x%02x at %ld"), + op, (long) (data - 1 - start)); + fprintf_filtered (stream, " %*ld: %s", indent + 4, + (long) (data - 1 - start), name); + + switch (op) + { + case DW_OP_addr: + ul = extract_unsigned_integer (data, addr_size, + gdbarch_byte_order (arch)); + data += addr_size; + fprintf_filtered (stream, " 0x%s", phex_nz (ul, addr_size)); + break; + + case DW_OP_const1u: + ul = extract_unsigned_integer (data, 1, gdbarch_byte_order (arch)); + data += 1; + fprintf_filtered (stream, " %s", pulongest (ul)); + break; + case DW_OP_const1s: + l = extract_signed_integer (data, 1, gdbarch_byte_order (arch)); + data += 1; + fprintf_filtered (stream, " %s", plongest (l)); + break; + case DW_OP_const2u: + ul = extract_unsigned_integer (data, 2, gdbarch_byte_order (arch)); + data += 2; + fprintf_filtered (stream, " %s", pulongest (ul)); + break; + case DW_OP_const2s: + l = extract_signed_integer (data, 2, gdbarch_byte_order (arch)); + data += 2; + fprintf_filtered (stream, " %s", plongest (l)); + break; + case DW_OP_const4u: + ul = extract_unsigned_integer (data, 4, gdbarch_byte_order (arch)); + data += 4; + fprintf_filtered (stream, " %s", pulongest (ul)); + break; + case DW_OP_const4s: + l = extract_signed_integer (data, 4, gdbarch_byte_order (arch)); + data += 4; + fprintf_filtered (stream, " %s", plongest (l)); + break; + case DW_OP_const8u: + ul = extract_unsigned_integer (data, 8, gdbarch_byte_order (arch)); + data += 8; + fprintf_filtered (stream, " %s", pulongest (ul)); + break; + case DW_OP_const8s: + l = extract_signed_integer (data, 8, gdbarch_byte_order (arch)); + data += 8; + fprintf_filtered (stream, " %s", plongest (l)); + break; + case DW_OP_constu: + data = safe_read_uleb128 (data, end, &ul); + fprintf_filtered (stream, " %s", pulongest (ul)); + break; + case DW_OP_consts: + data = safe_read_sleb128 (data, end, &l); + fprintf_filtered (stream, " %s", plongest (l)); + break; + + case DW_OP_reg0: + case DW_OP_reg1: + case DW_OP_reg2: + case DW_OP_reg3: + case DW_OP_reg4: + case DW_OP_reg5: + case DW_OP_reg6: + case DW_OP_reg7: + case DW_OP_reg8: + case DW_OP_reg9: + case DW_OP_reg10: + case DW_OP_reg11: + case DW_OP_reg12: + case DW_OP_reg13: + case DW_OP_reg14: + case DW_OP_reg15: + case DW_OP_reg16: + case DW_OP_reg17: + case DW_OP_reg18: + case DW_OP_reg19: + case DW_OP_reg20: + case DW_OP_reg21: + case DW_OP_reg22: + case DW_OP_reg23: + case DW_OP_reg24: + case DW_OP_reg25: + case DW_OP_reg26: + case DW_OP_reg27: + case DW_OP_reg28: + case DW_OP_reg29: + case DW_OP_reg30: + case DW_OP_reg31: + fprintf_filtered (stream, " [$%s]", + locexpr_regname (arch, op - DW_OP_reg0)); + break; + + case DW_OP_regx: + data = safe_read_uleb128 (data, end, &ul); + fprintf_filtered (stream, " %s [$%s]", pulongest (ul), + locexpr_regname (arch, (int) ul)); + break; + + case DW_OP_implicit_value: + data = safe_read_uleb128 (data, end, &ul); + data += ul; + fprintf_filtered (stream, " %s", pulongest (ul)); + break; + + case DW_OP_breg0: + case DW_OP_breg1: + case DW_OP_breg2: + case DW_OP_breg3: + case DW_OP_breg4: + case DW_OP_breg5: + case DW_OP_breg6: + case DW_OP_breg7: + case DW_OP_breg8: + case DW_OP_breg9: + case DW_OP_breg10: + case DW_OP_breg11: + case DW_OP_breg12: + case DW_OP_breg13: + case DW_OP_breg14: + case DW_OP_breg15: + case DW_OP_breg16: + case DW_OP_breg17: + case DW_OP_breg18: + case DW_OP_breg19: + case DW_OP_breg20: + case DW_OP_breg21: + case DW_OP_breg22: + case DW_OP_breg23: + case DW_OP_breg24: + case DW_OP_breg25: + case DW_OP_breg26: + case DW_OP_breg27: + case DW_OP_breg28: + case DW_OP_breg29: + case DW_OP_breg30: + case DW_OP_breg31: + data = safe_read_sleb128 (data, end, &l); + fprintf_filtered (stream, " %s [$%s]", plongest (l), + locexpr_regname (arch, op - DW_OP_breg0)); + break; + + case DW_OP_bregx: + data = safe_read_uleb128 (data, end, &ul); + data = safe_read_sleb128 (data, end, &l); + fprintf_filtered (stream, " register %s [$%s] offset %s", + pulongest (ul), + locexpr_regname (arch, (int) ul), + plongest (l)); + break; + + case DW_OP_fbreg: + data = safe_read_sleb128 (data, end, &l); + fprintf_filtered (stream, " %s", plongest (l)); + break; + + case DW_OP_xderef_size: + case DW_OP_deref_size: + case DW_OP_pick: + fprintf_filtered (stream, " %d", *data); + ++data; + break; + + case DW_OP_plus_uconst: + data = safe_read_uleb128 (data, end, &ul); + fprintf_filtered (stream, " %s", pulongest (ul)); + break; + + case DW_OP_skip: + l = extract_signed_integer (data, 2, gdbarch_byte_order (arch)); + data += 2; + fprintf_filtered (stream, " to %ld", + (long) (data + l - start)); + break; + + case DW_OP_bra: + l = extract_signed_integer (data, 2, gdbarch_byte_order (arch)); + data += 2; + fprintf_filtered (stream, " %ld", + (long) (data + l - start)); + break; + + case DW_OP_call2: + ul = extract_unsigned_integer (data, 2, gdbarch_byte_order (arch)); + data += 2; + fprintf_filtered (stream, " offset %s", phex_nz (ul, 2)); + break; + + case DW_OP_call4: + ul = extract_unsigned_integer (data, 4, gdbarch_byte_order (arch)); + data += 4; + fprintf_filtered (stream, " offset %s", phex_nz (ul, 4)); + break; + + case DW_OP_call_ref: + ul = extract_unsigned_integer (data, offset_size, + gdbarch_byte_order (arch)); + data += offset_size; + fprintf_filtered (stream, " offset %s", phex_nz (ul, offset_size)); + break; + + case DW_OP_piece: + data = safe_read_uleb128 (data, end, &ul); + fprintf_filtered (stream, " %s (bytes)", pulongest (ul)); + break; + + case DW_OP_bit_piece: + { + uint64_t offset; + + data = safe_read_uleb128 (data, end, &ul); + data = safe_read_uleb128 (data, end, &offset); + fprintf_filtered (stream, " size %s offset %s (bits)", + pulongest (ul), pulongest (offset)); + } + break; + + case DW_OP_GNU_implicit_pointer: + { + ul = extract_unsigned_integer (data, offset_size, + gdbarch_byte_order (arch)); + data += offset_size; + + data = safe_read_sleb128 (data, end, &l); + + fprintf_filtered (stream, " DIE %s offset %s", + phex_nz (ul, offset_size), + plongest (l)); + } + break; + + case DW_OP_GNU_deref_type: + { + int addr_size = *data++; + cu_offset offset; + struct type *type; + + data = safe_read_uleb128 (data, end, &ul); + offset.cu_off = ul; + type = dwarf2_get_die_type (offset, per_cu); + fprintf_filtered (stream, "<"); + type_print (type, "", stream, -1); + fprintf_filtered (stream, " [0x%s]> %d", phex_nz (offset.cu_off, 0), + addr_size); + } + break; + + case DW_OP_GNU_const_type: + { + cu_offset type_die; + struct type *type; + + data = safe_read_uleb128 (data, end, &ul); + type_die.cu_off = ul; + type = dwarf2_get_die_type (type_die, per_cu); + fprintf_filtered (stream, "<"); + type_print (type, "", stream, -1); + fprintf_filtered (stream, " [0x%s]>", phex_nz (type_die.cu_off, 0)); + } + break; + + case DW_OP_GNU_regval_type: + { + uint64_t reg; + cu_offset type_die; + struct type *type; + + data = safe_read_uleb128 (data, end, ®); + data = safe_read_uleb128 (data, end, &ul); + type_die.cu_off = ul; + + type = dwarf2_get_die_type (type_die, per_cu); + fprintf_filtered (stream, "<"); + type_print (type, "", stream, -1); + fprintf_filtered (stream, " [0x%s]> [$%s]", + phex_nz (type_die.cu_off, 0), + locexpr_regname (arch, reg)); + } + break; + + case DW_OP_GNU_convert: + case DW_OP_GNU_reinterpret: + { + cu_offset type_die; + + data = safe_read_uleb128 (data, end, &ul); + type_die.cu_off = ul; + + if (type_die.cu_off == 0) + fprintf_filtered (stream, "<0>"); + else + { + struct type *type; + + type = dwarf2_get_die_type (type_die, per_cu); + fprintf_filtered (stream, "<"); + type_print (type, "", stream, -1); + fprintf_filtered (stream, " [0x%s]>", phex_nz (type_die.cu_off, 0)); + } + } + break; + + case DW_OP_GNU_entry_value: + data = safe_read_uleb128 (data, end, &ul); + fputc_filtered ('\n', stream); + disassemble_dwarf_expression (stream, arch, addr_size, offset_size, + start, data, data + ul, indent + 2, + all, per_cu); + data += ul; + continue; + + case DW_OP_GNU_parameter_ref: + ul = extract_unsigned_integer (data, 4, gdbarch_byte_order (arch)); + data += 4; + fprintf_filtered (stream, " offset %s", phex_nz (ul, 4)); + break; + + case DW_OP_GNU_addr_index: + data = safe_read_uleb128 (data, end, &ul); + ul = dwarf2_read_addr_index (per_cu, ul); + fprintf_filtered (stream, " 0x%s", phex_nz (ul, addr_size)); + break; + case DW_OP_GNU_const_index: + data = safe_read_uleb128 (data, end, &ul); + ul = dwarf2_read_addr_index (per_cu, ul); + fprintf_filtered (stream, " %s", pulongest (ul)); + break; + } + + fprintf_filtered (stream, "\n"); + } return data; } @@ -1424,41 +3827,86 @@ locexpr_describe_location_piece (struct symbol *symbol, struct ui_file *stream, static void locexpr_describe_location_1 (struct symbol *symbol, CORE_ADDR addr, struct ui_file *stream, - const gdb_byte *data, int size, - struct objfile *objfile, unsigned int addr_size) + const gdb_byte *data, size_t size, + struct objfile *objfile, unsigned int addr_size, + int offset_size, struct dwarf2_per_cu_data *per_cu) { const gdb_byte *end = data + size; - int piece_done = 0, first_piece = 1, bad = 0; + int first_piece = 1, bad = 0; - /* A multi-piece description consists of multiple sequences of bytes - each followed by DW_OP_piece + length of piece. */ while (data < end) { - if (!piece_done) - { - if (first_piece) - first_piece = 0; - else - fprintf_filtered (stream, _(", and ")); + const gdb_byte *here = data; + int disassemble = 1; + + if (first_piece) + first_piece = 0; + else + fprintf_filtered (stream, _(", and ")); - data = locexpr_describe_location_piece (symbol, stream, addr, objfile, - data, size, addr_size); - piece_done = 1; + if (!dwarf2_always_disassemble) + { + data = locexpr_describe_location_piece (symbol, stream, + addr, objfile, per_cu, + data, end, addr_size); + /* If we printed anything, or if we have an empty piece, + then don't disassemble. */ + if (data != here + || data[0] == DW_OP_piece + || data[0] == DW_OP_bit_piece) + disassemble = 0; + } + if (disassemble) + { + fprintf_filtered (stream, _("a complex DWARF expression:\n")); + data = disassemble_dwarf_expression (stream, + get_objfile_arch (objfile), + addr_size, offset_size, data, + data, end, 0, + dwarf2_always_disassemble, + per_cu); } - else if (data[0] == DW_OP_piece) + + if (data < end) { - ULONGEST bytes; + int empty = data == here; - data = read_uleb128 (data + 1, end, &bytes); + if (disassemble) + fprintf_filtered (stream, " "); + if (data[0] == DW_OP_piece) + { + uint64_t bytes; - fprintf_filtered (stream, _(" [%s-byte piece]"), pulongest (bytes)); + data = safe_read_uleb128 (data + 1, end, &bytes); - piece_done = 0; - } - else - { - bad = 1; - break; + if (empty) + fprintf_filtered (stream, _("an empty %s-byte piece"), + pulongest (bytes)); + else + fprintf_filtered (stream, _(" [%s-byte piece]"), + pulongest (bytes)); + } + else if (data[0] == DW_OP_bit_piece) + { + uint64_t bits, offset; + + data = safe_read_uleb128 (data + 1, end, &bits); + data = safe_read_uleb128 (data, end, &offset); + + if (empty) + fprintf_filtered (stream, + _("an empty %s-bit piece"), + pulongest (bits)); + else + fprintf_filtered (stream, + _(" [%s-bit piece, offset %s bits]"), + pulongest (bits), pulongest (offset)); + } + else + { + bad = 1; + break; + } } } @@ -1477,9 +3925,12 @@ locexpr_describe_location (struct symbol *symbol, CORE_ADDR addr, struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol); struct objfile *objfile = dwarf2_per_cu_objfile (dlbaton->per_cu); unsigned int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu); + int offset_size = dwarf2_per_cu_offset_size (dlbaton->per_cu); - locexpr_describe_location_1 (symbol, addr, stream, dlbaton->data, dlbaton->size, - objfile, addr_size); + locexpr_describe_location_1 (symbol, addr, stream, + dlbaton->data, dlbaton->size, + objfile, addr_size, offset_size, + dlbaton->per_cu); } /* Describe the location of SYMBOL as an agent value in VALUE, generating @@ -1490,15 +3941,21 @@ locexpr_tracepoint_var_ref (struct symbol *symbol, struct gdbarch *gdbarch, struct agent_expr *ax, struct axs_value *value) { struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol); + unsigned int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu); - dwarf2_tracepoint_var_ref (symbol, gdbarch, ax, value, - dlbaton->data, dlbaton->size); + if (dlbaton->size == 0) + value->optimized_out = 1; + else + dwarf2_compile_expr_to_ax (ax, value, gdbarch, addr_size, + dlbaton->data, dlbaton->data + dlbaton->size, + dlbaton->per_cu); } /* The set of location functions used with the DWARF-2 expression evaluator. */ const struct symbol_computed_ops dwarf2_locexpr_funcs = { locexpr_read_variable, + locexpr_read_variable_at_entry, locexpr_read_needs_frame, locexpr_describe_location, locexpr_tracepoint_var_ref @@ -1517,23 +3974,41 @@ loclist_read_variable (struct symbol *symbol, struct frame_info *frame) struct value *val; const gdb_byte *data; size_t size; + CORE_ADDR pc = frame ? get_frame_address_in_block (frame) : 0; - data = find_location_expression (dlbaton, &size, - frame ? get_frame_address_in_block (frame) - : 0); - if (data == NULL) - { - val = allocate_value (SYMBOL_TYPE (symbol)); - VALUE_LVAL (val) = not_lval; - set_value_optimized_out (val, 1); - } - else - val = dwarf2_evaluate_loc_desc (SYMBOL_TYPE (symbol), frame, data, size, - dlbaton->per_cu); + data = dwarf2_find_location_expression (dlbaton, &size, pc); + val = dwarf2_evaluate_loc_desc (SYMBOL_TYPE (symbol), frame, data, size, + dlbaton->per_cu); return val; } +/* Read variable SYMBOL like loclist_read_variable at (callee) FRAME's function + entry. SYMBOL should be a function parameter, otherwise NO_ENTRY_VALUE_ERROR + will be thrown. + + Function always returns non-NULL value, it may be marked optimized out if + inferior frame information is not available. It throws NO_ENTRY_VALUE_ERROR + if it cannot resolve the parameter for any reason. */ + +static struct value * +loclist_read_variable_at_entry (struct symbol *symbol, struct frame_info *frame) +{ + struct dwarf2_loclist_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol); + const gdb_byte *data; + size_t size; + CORE_ADDR pc; + + if (frame == NULL || !get_frame_func_if_available (frame, &pc)) + return allocate_optimized_out_value (SYMBOL_TYPE (symbol)); + + data = dwarf2_find_location_expression (dlbaton, &size, pc); + if (data == NULL) + return allocate_optimized_out_value (SYMBOL_TYPE (symbol)); + + return value_of_dwarf_block_entry (SYMBOL_TYPE (symbol), frame, data, size); +} + /* Return non-zero iff we need a frame to evaluate SYMBOL. */ static int loclist_read_needs_frame (struct symbol *symbol) @@ -1556,54 +4031,61 @@ loclist_describe_location (struct symbol *symbol, CORE_ADDR addr, struct ui_file *stream) { struct dwarf2_loclist_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol); - CORE_ADDR low, high; const gdb_byte *loc_ptr, *buf_end; - int length, first = 1; + int first = 1; struct objfile *objfile = dwarf2_per_cu_objfile (dlbaton->per_cu); struct gdbarch *gdbarch = get_objfile_arch (objfile); enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); unsigned int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu); - CORE_ADDR base_mask = ~(~(CORE_ADDR)1 << (addr_size * 8 - 1)); + int offset_size = dwarf2_per_cu_offset_size (dlbaton->per_cu); + int signed_addr_p = bfd_get_sign_extend_vma (objfile->obfd); /* Adjust base_address for relocatable objects. */ - CORE_ADDR base_offset = ANOFFSET (objfile->section_offsets, - SECT_OFF_TEXT (objfile)); + CORE_ADDR base_offset = dwarf2_per_cu_text_offset (dlbaton->per_cu); CORE_ADDR base_address = dlbaton->base_address + base_offset; + int done = 0; loc_ptr = dlbaton->data; buf_end = dlbaton->data + dlbaton->size; - fprintf_filtered (stream, _("multi-location (")); + fprintf_filtered (stream, _("multi-location:\n")); /* Iterate through locations until we run out. */ - while (1) + while (!done) { - if (buf_end - loc_ptr < 2 * addr_size) - error (_("Corrupted DWARF expression for symbol \"%s\"."), - SYMBOL_PRINT_NAME (symbol)); - - low = extract_unsigned_integer (loc_ptr, addr_size, byte_order); - loc_ptr += addr_size; - - /* A base-address-selection entry. */ - if (low == base_mask) + CORE_ADDR low = 0, high = 0; /* init for gcc -Wall */ + int length; + enum debug_loc_kind kind; + const gdb_byte *new_ptr = NULL; /* init for gcc -Wall */ + + if (dlbaton->from_dwo) + kind = decode_debug_loc_dwo_addresses (dlbaton->per_cu, + loc_ptr, buf_end, &new_ptr, + &low, &high, byte_order); + else + kind = decode_debug_loc_addresses (loc_ptr, buf_end, &new_ptr, + &low, &high, + byte_order, addr_size, + signed_addr_p); + loc_ptr = new_ptr; + switch (kind) { - base_address = dwarf2_read_address (gdbarch, - loc_ptr, buf_end, addr_size); - fprintf_filtered (stream, _("[base address %s]"), + case DEBUG_LOC_END_OF_LIST: + done = 1; + continue; + case DEBUG_LOC_BASE_ADDRESS: + base_address = high + base_offset; + fprintf_filtered (stream, _(" Base address %s"), paddress (gdbarch, base_address)); - loc_ptr += addr_size; continue; - } - - high = extract_unsigned_integer (loc_ptr, addr_size, byte_order); - loc_ptr += addr_size; - - /* An end-of-list entry. */ - if (low == 0 && high == 0) - { - /* Indicate the end of the list, for readability. */ - fprintf_filtered (stream, _(")")); - return; + case DEBUG_LOC_START_END: + case DEBUG_LOC_START_LENGTH: + break; + case DEBUG_LOC_BUFFER_OVERFLOW: + case DEBUG_LOC_INVALID_ENTRY: + error (_("Corrupted DWARF expression for symbol \"%s\"."), + SYMBOL_PRINT_NAME (symbol)); + default: + gdb_assert_not_reached ("bad debug_loc_kind"); } /* Otherwise, a location expression entry. */ @@ -1613,20 +4095,17 @@ loclist_describe_location (struct symbol *symbol, CORE_ADDR addr, length = extract_unsigned_integer (loc_ptr, 2, byte_order); loc_ptr += 2; - /* Separate the different locations with a semicolon. */ - if (first) - first = 0; - else - fprintf_filtered (stream, _("; ")); - /* (It would improve readability to print only the minimum necessary digits of the second number of the range.) */ - fprintf_filtered (stream, _("range %s-%s, "), + fprintf_filtered (stream, _(" Range %s-%s: "), paddress (gdbarch, low), paddress (gdbarch, high)); /* Now describe this particular location. */ locexpr_describe_location_1 (symbol, low, stream, loc_ptr, length, - objfile, addr_size); + objfile, addr_size, offset_size, + dlbaton->per_cu); + + fprintf_filtered (stream, "\n"); loc_ptr += length; } @@ -1641,17 +4120,42 @@ loclist_tracepoint_var_ref (struct symbol *symbol, struct gdbarch *gdbarch, struct dwarf2_loclist_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol); const gdb_byte *data; size_t size; + unsigned int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu); - data = find_location_expression (dlbaton, &size, ax->scope); - - dwarf2_tracepoint_var_ref (symbol, gdbarch, ax, value, data, size); + data = dwarf2_find_location_expression (dlbaton, &size, ax->scope); + if (size == 0) + value->optimized_out = 1; + else + dwarf2_compile_expr_to_ax (ax, value, gdbarch, addr_size, data, data + size, + dlbaton->per_cu); } /* The set of location functions used with the DWARF-2 expression evaluator and location lists. */ const struct symbol_computed_ops dwarf2_loclist_funcs = { loclist_read_variable, + loclist_read_variable_at_entry, loclist_read_needs_frame, loclist_describe_location, loclist_tracepoint_var_ref }; + +/* Provide a prototype to silence -Wmissing-prototypes. */ +extern initialize_file_ftype _initialize_dwarf2loc; + +void +_initialize_dwarf2loc (void) +{ + add_setshow_zuinteger_cmd ("entry-values", class_maintenance, + &entry_values_debug, + _("Set entry values and tail call frames " + "debugging."), + _("Show entry values and tail call frames " + "debugging."), + _("When non-zero, the process of determining " + "parameter values from function entry point " + "and tail call frames will be printed."), + NULL, + show_entry_values_debug, + &setdebuglist, &showdebuglist); +}