X-Git-Url: http://drtracing.org/?a=blobdiff_plain;f=gdb%2Fdwarf2loc.c;h=e8d39feb8e4b93cba688bba384ba67491f763d66;hb=ffda88b4801e1ea163e7eb0962008c60f353c229;hp=64cc5e553c8d2ad5eebb6ae43a502b96115c1abc;hpb=72fc29ff1236177b2be5f702ed40c7d327897e7e;p=deliverable%2Fbinutils-gdb.git diff --git a/gdb/dwarf2loc.c b/gdb/dwarf2loc.c index 64cc5e553c..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, 2011 - 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" @@ -42,17 +42,154 @@ #include "gdb_string.h" #include "gdb_assert.h" +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 void dwarf_expr_frame_base_1 (struct symbol *framefunc, CORE_ADDR pc, + const gdb_byte **start, size_t *length); -static struct value * -dwarf2_evaluate_loc_desc_full (struct type *type, struct frame_info *frame, - const gdb_byte *data, unsigned short size, - struct dwarf2_per_cu_data *per_cu, - LONGEST byte_offset); +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 function for dealing with location lists. Given a symbol baton (BATON) and a pc value (PC), find the appropriate @@ -66,51 +203,55 @@ 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); int signed_addr_p = bfd_get_sign_extend_vma (objfile->obfd); - CORE_ADDR base_mask = ~(~(CORE_ADDR)1 << (addr_size * 8 - 1)); /* Adjust base_address for relocatable objects. */ 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 (_("dwarf2_find_location_expression: " - "Corrupted DWARF expression.")); - - 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); + 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 - high = extract_unsigned_integer (loc_ptr, addr_size, byte_order); - loc_ptr += addr_size; - - /* A base-address-selection entry. */ - if ((low & base_mask) == base_mask) + 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) { + 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"); } - /* An end-of-list entry. */ - if (low == 0 && high == 0) - return NULL; - /* Otherwise, a location expression entry. */ low += base_address; high += base_address; @@ -118,6 +259,24 @@ dwarf2_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; @@ -194,7 +353,7 @@ 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; @@ -213,10 +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)); } @@ -259,7 +418,7 @@ dwarf_expr_tls_address (void *baton, CORE_ADDR offset) call and return. */ static void -per_cu_dwarf_call (struct dwarf_expr_context *ctx, size_t die_offset, +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) @@ -278,24 +437,881 @@ per_cu_dwarf_call (struct dwarf_expr_context *ctx, size_t die_offset, /* Helper interface of per_cu_dwarf_call for dwarf2_evaluate_loc_desc. */ static void -dwarf_expr_dwarf_call (struct dwarf_expr_context *ctx, size_t die_offset) +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->get_frame_pc, ctx->baton); + 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, size_t die_offset) +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. */ @@ -964,10 +1980,9 @@ indirect_pieced_value (struct value *value) struct dwarf2_locexpr_baton baton; int i, bit_offset, bit_length; struct dwarf_expr_piece *piece = NULL; - struct value *result; LONGEST byte_offset; - type = value_type (value); + type = check_typedef (value_type (value)); if (TYPE_CODE (type) != TYPE_CODE_PTR) return NULL; @@ -1006,6 +2021,8 @@ indirect_pieced_value (struct value *value) } 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); @@ -1013,11 +2030,9 @@ indirect_pieced_value (struct value *value) get_frame_address_in_block_wrapper, frame); - result = dwarf2_evaluate_loc_desc_full (TYPE_TARGET_TYPE (type), frame, - baton.data, baton.size, baton.per_cu, - byte_offset); - - return result; + 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 * @@ -1051,12 +2066,13 @@ free_pieced_value_closure (struct value *v) } /* 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 @@ -1072,6 +2088,22 @@ invalid_synthetic_pointer (void) "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. BYTE_OFFSET is applied after the contents are @@ -1079,7 +2111,7 @@ invalid_synthetic_pointer (void) static struct value * dwarf2_evaluate_loc_desc_full (struct type *type, struct frame_info *frame, - const gdb_byte *data, unsigned short size, + const gdb_byte *data, size_t size, struct dwarf2_per_cu_data *per_cu, LONGEST byte_offset) { @@ -1094,12 +2126,7 @@ dwarf2_evaluate_loc_desc_full (struct type *type, struct frame_info *frame, 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.per_cu = per_cu; @@ -1110,16 +2137,10 @@ dwarf2_evaluate_loc_desc_full (struct type *type, struct frame_info *frame, 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_frame_pc = dwarf_expr_frame_pc; - ctx->get_tls_address = dwarf_expr_tls_address; - ctx->dwarf_call = dwarf_expr_dwarf_call; - ctx->get_base_type = dwarf_expr_get_base_type; + ctx->funcs = &dwarf_expr_ctx_funcs; TRY_CATCH (ex, RETURN_MASK_ERROR) { @@ -1134,6 +2155,13 @@ dwarf2_evaluate_loc_desc_full (struct type *type, struct frame_info *frame, 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); } @@ -1218,7 +2246,13 @@ dwarf2_evaluate_loc_desc_full (struct type *type, struct frame_info *frame, retval = allocate_value (type); contents = value_contents_raw (retval); if (n > TYPE_LENGTH (type)) - n = TYPE_LENGTH (type); + { + 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; @@ -1240,16 +2274,20 @@ dwarf2_evaluate_loc_desc_full (struct type *type, struct frame_info *frame, n -= byte_offset; if (n > TYPE_LENGTH (type)) - n = TYPE_LENGTH (type); + { + 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_value (type); - VALUE_LVAL (retval) = not_lval; - set_value_optimized_out (retval, 1); + retval = allocate_optimized_out_value (type); break; /* DWARF_VALUE_IMPLICIT_POINTER was converted to a pieced @@ -1274,7 +2312,7 @@ dwarf2_evaluate_loc_desc_full (struct type *type, struct frame_info *frame, struct value * dwarf2_evaluate_loc_desc (struct type *type, struct frame_info *frame, - const gdb_byte *data, unsigned short size, + 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); @@ -1343,19 +2381,59 @@ needs_frame_tls_address (void *baton, CORE_ADDR offset) /* Helper interface of per_cu_dwarf_call for dwarf2_loc_desc_needs_frame. */ static void -needs_frame_dwarf_call (struct dwarf_expr_context *ctx, size_t die_offset) +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->get_frame_pc, ctx->baton); + 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; @@ -1373,15 +2451,10 @@ dwarf2_loc_desc_needs_frame (const gdb_byte *data, unsigned short size, 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_frame_pc = needs_frame_frame_cfa; - ctx->get_tls_address = needs_frame_tls_address; - ctx->dwarf_call = needs_frame_dwarf_call; + ctx->funcs = &needs_frame_ctx_funcs; dwarf_expr_eval (ctx, data, size); @@ -1409,7 +2482,7 @@ dwarf2_loc_desc_needs_frame (const gdb_byte *data, unsigned short size, static void unimplemented (unsigned int op) { - const char *name = dwarf_stack_op_name (op); + const char *name = get_DW_OP_name (op); if (name) error (_("DWARF operator %s cannot be translated to an agent expression"), @@ -1532,8 +2605,8 @@ dwarf2_compile_expr_to_ax (struct agent_expr *expr, struct axs_value *loc, while (op_ptr < op_end) { enum dwarf_location_atom op = *op_ptr; - ULONGEST uoffset, reg; - LONGEST offset; + uint64_t uoffset, reg; + int64_t offset; int i; offsets[op_ptr - base] = expr->len; @@ -1637,11 +2710,11 @@ dwarf2_compile_expr_to_ax (struct agent_expr *expr, struct axs_value *loc, op_ptr += 8; break; case DW_OP_constu: - op_ptr = read_uleb128 (op_ptr, op_end, &uoffset); + op_ptr = safe_read_uleb128 (op_ptr, op_end, &uoffset); ax_const_l (expr, uoffset); break; case DW_OP_consts: - op_ptr = read_sleb128 (op_ptr, op_end, &offset); + op_ptr = safe_read_sleb128 (op_ptr, op_end, &offset); ax_const_l (expr, offset); break; @@ -1683,7 +2756,7 @@ dwarf2_compile_expr_to_ax (struct agent_expr *expr, struct axs_value *loc, break; case DW_OP_regx: - op_ptr = read_uleb128 (op_ptr, op_end, ®); + 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; @@ -1691,9 +2764,9 @@ dwarf2_compile_expr_to_ax (struct agent_expr *expr, struct axs_value *loc, case DW_OP_implicit_value: { - ULONGEST len; + uint64_t len; - op_ptr = read_uleb128 (op_ptr, op_end, &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)) @@ -1747,7 +2820,7 @@ dwarf2_compile_expr_to_ax (struct agent_expr *expr, struct axs_value *loc, case DW_OP_breg29: case DW_OP_breg30: case DW_OP_breg31: - op_ptr = read_sleb128 (op_ptr, op_end, &offset); + 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) @@ -1758,8 +2831,8 @@ dwarf2_compile_expr_to_ax (struct agent_expr *expr, struct axs_value *loc, break; case DW_OP_bregx: { - op_ptr = read_uleb128 (op_ptr, op_end, ®); - op_ptr = read_sleb128 (op_ptr, op_end, &offset); + 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) @@ -1773,7 +2846,6 @@ dwarf2_compile_expr_to_ax (struct agent_expr *expr, struct axs_value *loc, { const gdb_byte *datastart; size_t datalen; - unsigned int before_stack_len; struct block *b; struct symbol *framefunc; LONGEST base_offset = 0; @@ -1791,7 +2863,7 @@ dwarf2_compile_expr_to_ax (struct agent_expr *expr, struct axs_value *loc, dwarf_expr_frame_base_1 (framefunc, expr->scope, &datastart, &datalen); - op_ptr = read_sleb128 (op_ptr, op_end, &offset); + 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); @@ -1855,10 +2927,10 @@ dwarf2_compile_expr_to_ax (struct agent_expr *expr, struct axs_value *loc, ax_simple (expr, aop_ref64); break; default: - /* Note that dwarf_stack_op_name will never return + /* Note that get_DW_OP_name will never return NULL here. */ error (_("Unsupported size %d in %s"), - size, dwarf_stack_op_name (op)); + size, get_DW_OP_name (op)); } } break; @@ -1892,7 +2964,7 @@ dwarf2_compile_expr_to_ax (struct agent_expr *expr, struct axs_value *loc, break; case DW_OP_plus_uconst: - op_ptr = read_uleb128 (op_ptr, op_end, ®); + 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) @@ -2042,20 +3114,20 @@ dwarf2_compile_expr_to_ax (struct agent_expr *expr, struct axs_value *loc, case DW_OP_piece: case DW_OP_bit_piece: { - ULONGEST size, offset; + uint64_t size, offset; if (op_ptr - 1 == previous_piece) error (_("Cannot translate empty pieces to agent expressions")); previous_piece = op_ptr - 1; - op_ptr = read_uleb128 (op_ptr, op_end, &size); + op_ptr = safe_read_uleb128 (op_ptr, op_end, &size); if (op == DW_OP_piece) { size *= 8; offset = 0; } else - op_ptr = read_uleb128 (op_ptr, op_end, &offset); + op_ptr = safe_read_uleb128 (op_ptr, op_end, &offset); if (bits_collected + size > 8 * sizeof (LONGEST)) error (_("Expression pieces exceed word size")); @@ -2115,11 +3187,13 @@ dwarf2_compile_expr_to_ax (struct agent_expr *expr, struct axs_value *loc, { struct dwarf2_locexpr_baton block; int size = (op == DW_OP_call2 ? 2 : 4); + cu_offset offset; uoffset = extract_unsigned_integer (op_ptr, size, byte_order); op_ptr += size; - block = dwarf2_fetch_die_location_block (uoffset, per_cu, + 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. */ @@ -2166,6 +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) @@ -2185,47 +3272,59 @@ 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. */ + 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, + 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, end, ®); - 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; + 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 = read_sleb128 (data + 1, end, &frame_offset); + new_data = safe_read_sleb128 (data + 1, end, &frame_offset); if (!piece_end_p (new_data, end)) return data; data = new_data; @@ -2249,8 +3348,8 @@ 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\"."), @@ -2269,26 +3368,22 @@ locexpr_describe_location_piece (struct symbol *symbol, struct ui_file *stream, return save_data; } - regno = gdbarch_dwarf2_reg_to_regnum (gdbarch, frame_reg); - fprintf_filtered (stream, _("a variable at frame base reg $%s offset %s+%s"), - gdbarch_register_name (gdbarch, regno), + locexpr_regname (gdbarch, frame_reg), plongest (base_offset), plongest (frame_offset)); } 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, end, &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 @@ -2323,6 +3418,29 @@ locexpr_describe_location_piece (struct symbol *symbol, struct ui_file *stream, data += 1 + addr_size + 1; } + + /* 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 @@ -2338,34 +3456,34 @@ locexpr_describe_location_piece (struct symbol *symbol, struct ui_file *stream, /* 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. */ + 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, + int offset_size, const gdb_byte *start, const gdb_byte *data, const gdb_byte *end, - int all) + int indent, int all, + struct dwarf2_per_cu_data *per_cu) { - const gdb_byte *start = data; - - fprintf_filtered (stream, _("a complex DWARF expression:\n")); - while (data < end && (all || (data[0] != DW_OP_piece && data[0] != DW_OP_bit_piece))) { enum dwarf_location_atom op = *data++; - ULONGEST ul; - LONGEST l; + uint64_t ul; + int64_t l; const char *name; - name = dwarf_stack_op_name (op); + name = get_DW_OP_name (op); if (!name) error (_("Unrecognized DWARF opcode 0x%02x at %ld"), - op, (long) (data - start)); - fprintf_filtered (stream, " % 4ld: %s", (long) (data - start), name); + op, (long) (data - 1 - start)); + fprintf_filtered (stream, " %*ld: %s", indent + 4, + (long) (data - 1 - start), name); switch (op) { @@ -2417,11 +3535,11 @@ disassemble_dwarf_expression (struct ui_file *stream, fprintf_filtered (stream, " %s", plongest (l)); break; case DW_OP_constu: - data = read_uleb128 (data, end, &ul); + data = safe_read_uleb128 (data, end, &ul); fprintf_filtered (stream, " %s", pulongest (ul)); break; case DW_OP_consts: - data = read_sleb128 (data, end, &l); + data = safe_read_sleb128 (data, end, &l); fprintf_filtered (stream, " %s", plongest (l)); break; @@ -2458,17 +3576,17 @@ disassemble_dwarf_expression (struct ui_file *stream, case DW_OP_reg30: case DW_OP_reg31: fprintf_filtered (stream, " [$%s]", - gdbarch_register_name (arch, op - DW_OP_reg0)); + locexpr_regname (arch, op - DW_OP_reg0)); break; case DW_OP_regx: - data = read_uleb128 (data, end, &ul); + data = safe_read_uleb128 (data, end, &ul); fprintf_filtered (stream, " %s [$%s]", pulongest (ul), - gdbarch_register_name (arch, (int) ul)); + locexpr_regname (arch, (int) ul)); break; case DW_OP_implicit_value: - data = read_uleb128 (data, end, &ul); + data = safe_read_uleb128 (data, end, &ul); data += ul; fprintf_filtered (stream, " %s", pulongest (ul)); break; @@ -2505,22 +3623,22 @@ disassemble_dwarf_expression (struct ui_file *stream, case DW_OP_breg29: case DW_OP_breg30: case DW_OP_breg31: - data = read_sleb128 (data, end, &l); + data = safe_read_sleb128 (data, end, &l); fprintf_filtered (stream, " %s [$%s]", plongest (l), - gdbarch_register_name (arch, op - DW_OP_breg0)); + locexpr_regname (arch, op - DW_OP_breg0)); break; case DW_OP_bregx: - data = read_uleb128 (data, end, &ul); - data = read_sleb128 (data, end, &l); + data = safe_read_uleb128 (data, end, &ul); + data = safe_read_sleb128 (data, end, &l); fprintf_filtered (stream, " register %s [$%s] offset %s", pulongest (ul), - gdbarch_register_name (arch, (int) ul), + locexpr_regname (arch, (int) ul), plongest (l)); break; case DW_OP_fbreg: - data = read_sleb128 (data, end, &l); + data = safe_read_sleb128 (data, end, &l); fprintf_filtered (stream, " %s", plongest (l)); break; @@ -2532,7 +3650,7 @@ disassemble_dwarf_expression (struct ui_file *stream, break; case DW_OP_plus_uconst: - data = read_uleb128 (data, end, &ul); + data = safe_read_uleb128 (data, end, &ul); fprintf_filtered (stream, " %s", pulongest (ul)); break; @@ -2570,16 +3688,16 @@ disassemble_dwarf_expression (struct ui_file *stream, break; case DW_OP_piece: - data = read_uleb128 (data, end, &ul); + data = safe_read_uleb128 (data, end, &ul); fprintf_filtered (stream, " %s (bytes)", pulongest (ul)); break; case DW_OP_bit_piece: { - ULONGEST offset; + uint64_t offset; - data = read_uleb128 (data, end, &ul); - data = read_uleb128 (data, end, &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)); } @@ -2591,13 +3709,110 @@ disassemble_dwarf_expression (struct ui_file *stream, gdbarch_byte_order (arch)); data += offset_size; - data = read_sleb128 (data, end, &l); + 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"); @@ -2612,9 +3827,9 @@ disassemble_dwarf_expression (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, + const gdb_byte *data, size_t size, struct objfile *objfile, unsigned int addr_size, - int offset_size) + int offset_size, struct dwarf2_per_cu_data *per_cu) { const gdb_byte *end = data + size; int first_piece = 1, bad = 0; @@ -2632,7 +3847,7 @@ locexpr_describe_location_1 (struct symbol *symbol, CORE_ADDR addr, if (!dwarf2_always_disassemble) { data = locexpr_describe_location_piece (symbol, stream, - addr, objfile, + addr, objfile, per_cu, data, end, addr_size); /* If we printed anything, or if we have an empty piece, then don't disassemble. */ @@ -2642,10 +3857,15 @@ locexpr_describe_location_1 (struct symbol *symbol, CORE_ADDR addr, disassemble = 0; } if (disassemble) - data = disassemble_dwarf_expression (stream, - get_objfile_arch (objfile), - addr_size, offset_size, data, end, - dwarf2_always_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); + } if (data < end) { @@ -2655,9 +3875,9 @@ locexpr_describe_location_1 (struct symbol *symbol, CORE_ADDR addr, fprintf_filtered (stream, " "); if (data[0] == DW_OP_piece) { - ULONGEST bytes; + uint64_t bytes; - data = read_uleb128 (data + 1, end, &bytes); + data = safe_read_uleb128 (data + 1, end, &bytes); if (empty) fprintf_filtered (stream, _("an empty %s-byte piece"), @@ -2668,10 +3888,10 @@ locexpr_describe_location_1 (struct symbol *symbol, CORE_ADDR addr, } else if (data[0] == DW_OP_bit_piece) { - ULONGEST bits, offset; + uint64_t bits, offset; - data = read_uleb128 (data + 1, end, &bits); - data = read_uleb128 (data, end, &offset); + data = safe_read_uleb128 (data + 1, end, &bits); + data = safe_read_uleb128 (data, end, &offset); if (empty) fprintf_filtered (stream, @@ -2709,7 +3929,8 @@ locexpr_describe_location (struct symbol *symbol, CORE_ADDR addr, locexpr_describe_location_1 (symbol, addr, stream, dlbaton->data, dlbaton->size, - objfile, addr_size, offset_size); + objfile, addr_size, offset_size, + dlbaton->per_cu); } /* Describe the location of SYMBOL as an agent value in VALUE, generating @@ -2722,7 +3943,7 @@ locexpr_tracepoint_var_ref (struct symbol *symbol, struct gdbarch *gdbarch, struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol); unsigned int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu); - if (dlbaton->data == NULL || dlbaton->size == 0) + if (dlbaton->size == 0) value->optimized_out = 1; else dwarf2_compile_expr_to_ax (ax, value, gdbarch, addr_size, @@ -2734,6 +3955,7 @@ locexpr_tracepoint_var_ref (struct symbol *symbol, struct gdbarch *gdbarch, 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 @@ -2755,19 +3977,38 @@ loclist_read_variable (struct symbol *symbol, struct frame_info *frame) CORE_ADDR pc = frame ? get_frame_address_in_block (frame) : 0; data = dwarf2_find_location_expression (dlbaton, &size, pc); - 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); + 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) @@ -2790,19 +4031,18 @@ 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); int offset_size = dwarf2_per_cu_offset_size (dlbaton->per_cu); int signed_addr_p = bfd_get_sign_extend_vma (objfile->obfd); - CORE_ADDR base_mask = ~(~(CORE_ADDR)1 << (addr_size * 8 - 1)); /* Adjust base_address for relocatable objects. */ 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; @@ -2810,37 +4050,44 @@ loclist_describe_location (struct symbol *symbol, CORE_ADDR addr, 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)); - - if (signed_addr_p) - low = extract_signed_integer (loc_ptr, addr_size, byte_order); + 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 - 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; - - /* A base-address-selection entry. */ - if ((low & base_mask) == base_mask) + 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) { + 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)); continue; + 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"); } - /* An end-of-list entry. */ - if (low == 0 && high == 0) - break; - /* Otherwise, a location expression entry. */ low += base_address; high += base_address; @@ -2855,7 +4102,8 @@ loclist_describe_location (struct symbol *symbol, CORE_ADDR addr, /* Now describe this particular location. */ locexpr_describe_location_1 (symbol, low, stream, loc_ptr, length, - objfile, addr_size, offset_size); + objfile, addr_size, offset_size, + dlbaton->per_cu); fprintf_filtered (stream, "\n"); @@ -2875,7 +4123,7 @@ loclist_tracepoint_var_ref (struct symbol *symbol, struct gdbarch *gdbarch, unsigned int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu); data = dwarf2_find_location_expression (dlbaton, &size, ax->scope); - if (data == NULL || size == 0) + if (size == 0) value->optimized_out = 1; else dwarf2_compile_expr_to_ax (ax, value, gdbarch, addr_size, data, data + size, @@ -2886,7 +4134,28 @@ loclist_tracepoint_var_ref (struct symbol *symbol, struct gdbarch *gdbarch, 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); +}