/* Test program for dwarf location functions. Copyright (C) 2013, 2015 Red Hat, Inc. This file is part of elfutils. This file is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. elfutils is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>. */ #include <config.h> #include <assert.h> #include <argp.h> #include <inttypes.h> #include <errno.h> #include ELFUTILS_HEADER(dw) #include ELFUTILS_HEADER(dwfl) #include <dwarf.h> #include <stdio.h> #include <stdlib.h> #include <error.h> #include <string.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <unistd.h> #include "../libdw/known-dwarf.h" // The Dwarf, Dwarf_CFIs and address bias of // cfi table to adjust DWARF addresses against. // Needed for DW_OP_call_frame_cfa. static Dwarf *dw; Dwarf_CFI *cfi_debug; Dwarf_CFI *cfi_eh; Dwarf_Addr cfi_eh_bias; // Whether the current function has a DW_AT_frame_base defined. // Needed for DW_OP_fbreg. bool has_frame_base; static void print_die (Dwarf_Die *die, const char *what, int indent) { Dwarf_Addr entrypc; const char *name = dwarf_diename (die) ?: "<unknown>"; if (dwarf_entrypc (die, &entrypc) == 0) printf ("%*s[%" PRIx64 "] %s '%s'@%" PRIx64 "\n", indent * 2, "", dwarf_dieoffset (die), what, name, entrypc); else printf ("%*s[%" PRIx64 "] %s '%s'\n", indent * 2, "", dwarf_dieoffset (die), what, name); } static const char * dwarf_encoding_string (unsigned int code) { static const char *const known[] = { #define DWARF_ONE_KNOWN_DW_ATE(NAME, CODE) [CODE] = #NAME, DWARF_ALL_KNOWN_DW_ATE #undef DWARF_ONE_KNOWN_DW_ATE }; if (likely (code < sizeof (known) / sizeof (known[0]))) return known[code]; return NULL; } /* BASE must be a base type DIE referenced by a typed DWARF expression op. */ static void print_base_type (Dwarf_Die *base) { assert (dwarf_tag (base) == DW_TAG_base_type); Dwarf_Attribute encoding; Dwarf_Word enctype = 0; if (dwarf_attr (base, DW_AT_encoding, &encoding) == NULL || dwarf_formudata (&encoding, &enctype) != 0) error (EXIT_FAILURE, 0, "base type without encoding"); Dwarf_Attribute bsize; Dwarf_Word bits; if (dwarf_attr (base, DW_AT_byte_size, &bsize) != NULL && dwarf_formudata (&bsize, &bits) == 0) bits *= 8; else if (dwarf_attr (base, DW_AT_bit_size, &bsize) == NULL || dwarf_formudata (&bsize, &bits) != 0) error (EXIT_FAILURE, 0, "base type without byte or bit size"); printf ("{%s,%s,%" PRIu64 "@[%" PRIx64 "]}", dwarf_diename (base), dwarf_encoding_string (enctype), bits, dwarf_dieoffset (base)); } static const char * dwarf_opcode_string (unsigned int code) { static const char *const known[] = { #define DWARF_ONE_KNOWN_DW_OP(NAME, CODE) [CODE] = #NAME, DWARF_ALL_KNOWN_DW_OP #undef DWARF_ONE_KNOWN_DW_OP }; if (likely (code < sizeof (known) / sizeof (known[0]))) return known[code]; return NULL; } // Forward reference for print_expr_block. static void print_expr (Dwarf_Attribute *, Dwarf_Op *, Dwarf_Addr); static void print_expr_block (Dwarf_Attribute *attr, Dwarf_Op *exprs, int len, Dwarf_Addr addr) { printf ("{"); for (int i = 0; i < len; i++) { print_expr (attr, &exprs[i], addr); printf ("%s", (i + 1 < len ? ", " : "")); } printf ("}"); } static void print_expr_block_addrs (Dwarf_Attribute *attr, Dwarf_Addr begin, Dwarf_Addr end, Dwarf_Op *exprs, int len) { printf (" [%" PRIx64 ",%" PRIx64 ") ", begin, end); print_expr_block (attr, exprs, len, begin); printf ("\n"); } static void print_expr (Dwarf_Attribute *attr, Dwarf_Op *expr, Dwarf_Addr addr) { uint8_t atom = expr->atom; const char *opname = dwarf_opcode_string (atom); assert (opname != NULL); switch (atom) { case DW_OP_deref: case DW_OP_dup: case DW_OP_drop: case DW_OP_over: case DW_OP_swap: case DW_OP_rot: case DW_OP_xderef: case DW_OP_abs: case DW_OP_and: case DW_OP_div: case DW_OP_minus: case DW_OP_mod: case DW_OP_mul: case DW_OP_neg: case DW_OP_not: case DW_OP_or: case DW_OP_plus: case DW_OP_shl: case DW_OP_shr: case DW_OP_shra: case DW_OP_xor: case DW_OP_eq: case DW_OP_ge: case DW_OP_gt: case DW_OP_le: case DW_OP_lt: case DW_OP_ne: case DW_OP_lit0 ... DW_OP_lit31: case DW_OP_reg0 ... DW_OP_reg31: case DW_OP_nop: case DW_OP_stack_value: /* No arguments. */ printf ("%s", opname); break; case DW_OP_form_tls_address: /* No arguments. Special. Pops an address and pushes the corresponding address in the current thread local storage. Uses the thread local storage block of the defining module (executable, shared library). */ printf ("%s", opname); break; case DW_OP_GNU_push_tls_address: /* No arguments. Special. Not the same as DW_OP_form_tls_address. Pops an offset into the current thread local strorage and pushes back the actual address. */ printf ("%s", opname); break; case DW_OP_call_frame_cfa: /* No arguments. Special. Pushes Call Frame Address as computed by CFI data (dwarf_cfi_addrframe will fetch that info (either from the .eh_frame or .debug_frame CFI) and dwarf_frame_cfa translatesr the CFI instructions into a plain DWARF expression. Never used in CFI itself. */ if (attr == NULL) error (EXIT_FAILURE, 0, "%s used in CFI", opname); printf ("%s ", opname); if (cfi_eh == NULL && cfi_debug == NULL) error (EXIT_FAILURE, 0, "DW_OP_call_frame_cfa used but no cfi found."); Dwarf_Frame *frame; if (dwarf_cfi_addrframe (cfi_eh, addr + cfi_eh_bias, &frame) != 0 && dwarf_cfi_addrframe (cfi_debug, addr, &frame) != 0) error (EXIT_FAILURE, 0, "dwarf_cfi_addrframe 0x%" PRIx64 ": %s", addr, dwarf_errmsg (-1)); Dwarf_Op *cfa_ops; size_t cfa_nops; if (dwarf_frame_cfa (frame, &cfa_ops, &cfa_nops) != 0) error (EXIT_FAILURE, 0, "dwarf_frame_cfa 0x%" PRIx64 ": %s", addr, dwarf_errmsg (-1)); if (cfa_nops < 1) error (EXIT_FAILURE, 0, "dwarf_frame_cfa no ops"); print_expr_block (NULL, cfa_ops, cfa_nops, 0); free (frame); break; case DW_OP_push_object_address: /* No arguments. Special. Pushes object address explicitly. Normally only done implicitly by DW_AT_data_member_location. Never used in CFI. */ if (attr == NULL) error (EXIT_FAILURE, 0, "%s used in CFI", opname); printf ("%s", opname); break; case DW_OP_addr: /* 1 address argument. */ printf ("%s(0x%" PRIx64 ")", opname, (Dwarf_Addr) expr->number); break; case DW_OP_const1u: case DW_OP_const2u: case DW_OP_const4u: case DW_OP_const8u: case DW_OP_constu: case DW_OP_pick: case DW_OP_plus_uconst: case DW_OP_regx: case DW_OP_piece: case DW_OP_deref_size: case DW_OP_xderef_size: /* 1 numeric unsigned argument. */ printf ("%s(%" PRIu64 ")", opname, expr->number); break; case DW_OP_call2: case DW_OP_call4: case DW_OP_call_ref: /* 1 DIE offset argument for more ops in location attribute of DIE. Never used in CFI. */ { if (attr == NULL) error (EXIT_FAILURE, 0, "%s used in CFI", opname); Dwarf_Attribute call_attr; if (dwarf_getlocation_attr (attr, expr, &call_attr) != 0) error (EXIT_FAILURE, 0, "dwarf_getlocation_attr for %s error %s", opname, dwarf_errmsg (-1)); Dwarf_Die call_die; if (dwarf_getlocation_die (attr, expr, &call_die) != 0) error (EXIT_FAILURE, 0, "dwarf_getlocation_die for %s error %s", opname, dwarf_errmsg (-1)); Dwarf_Op *call_ops; size_t call_len; if (dwarf_getlocation (&call_attr, &call_ops, &call_len) != 0) error (EXIT_FAILURE, 0, "dwarf_getlocation for entry: %s", dwarf_errmsg (-1)); printf ("%s([%" PRIx64 "]) ", opname, dwarf_dieoffset (&call_die)); print_expr_block (&call_attr, call_ops, call_len, addr); } break; case DW_OP_const1s: case DW_OP_const2s: case DW_OP_const4s: case DW_OP_const8s: case DW_OP_consts: case DW_OP_skip: case DW_OP_bra: case DW_OP_breg0 ... DW_OP_breg31: /* 1 numeric signed argument. */ printf ("%s(%" PRId64 ")", opname, (Dwarf_Sword) expr->number); break; case DW_OP_fbreg: /* 1 numeric signed argument. Offset from frame base. */ if (attr == NULL) error (EXIT_FAILURE, 0, "%s used in CFI", opname); if (! has_frame_base) error (EXIT_FAILURE, 0, "DW_OP_fbreg used without a frame base"); printf ("%s(%" PRId64 ")", opname, (Dwarf_Sword) expr->number); break; case DW_OP_bregx: /* 2 arguments, unsigned register number, signed offset. */ printf ("%s(%" PRIu64 ",%" PRId64 ")", opname, expr->number, (Dwarf_Sword) expr->number2); break; case DW_OP_bit_piece: /* 2 arguments, unsigned size, unsigned offset. */ printf ("%s(%" PRIu64 ",%" PRIu64 ")", opname, expr->number, expr->number2); break; case DW_OP_implicit_value: /* Special, unsigned size plus block. */ { Dwarf_Attribute const_attr; Dwarf_Block block; if (dwarf_getlocation_attr (attr, expr, &const_attr) != 0) error (EXIT_FAILURE, 0, "dwarf_getlocation_attr: %s", dwarf_errmsg (-1)); if (dwarf_formblock (&const_attr, &block) != 0) error (EXIT_FAILURE, 0, "dwarf_formblock: %s", dwarf_errmsg (-1)); /* This is the "old" way. Check they result in the same. */ Dwarf_Block block_impl; if (dwarf_getlocation_implicit_value (attr, expr, &block_impl) != 0) error (EXIT_FAILURE, 0, "dwarf_getlocation_implicit_value: %s", dwarf_errmsg (-1)); assert (expr->number == block.length); assert (block.length == block_impl.length); printf ("%s(%" PRIu64 "){", opname, block.length); for (size_t i = 0; i < block.length; i++) { printf ("%02x", block.data[i]); assert (block.data[i] == block_impl.data[i]); } printf("}"); } break; case DW_OP_GNU_implicit_pointer: /* Special, DIE offset, signed offset. Referenced DIE has a location or const_value attribute. */ { if (attr == NULL) error (EXIT_FAILURE, 0, "%s used in CFI", opname); Dwarf_Attribute attrval; if (dwarf_getlocation_implicit_pointer (attr, expr, &attrval) != 0) error (EXIT_FAILURE, 0, "dwarf_getlocation_implicit_pointer: %s", dwarf_errmsg (-1)); // Sanity check, results should be the same. Dwarf_Attribute attrval2; if (dwarf_getlocation_attr (attr, expr, &attrval2) != 0) error (EXIT_FAILURE, 0, "dwarf_getlocation_attr: %s", dwarf_errmsg (-1)); assert (dwarf_whatattr (&attrval) == dwarf_whatattr (&attrval2)); assert (dwarf_whatform (&attrval) == dwarf_whatform (&attrval2)); // In theory two different valp pointers could point to the same // value. But here we really expect them to be the equal. assert (attrval.valp == attrval2.valp); Dwarf_Die impl_die; if (dwarf_getlocation_die (attr, expr, &impl_die) != 0) error (EXIT_FAILURE, 0, "dwarf_getlocation_due: %s", dwarf_errmsg (-1)); printf ("%s([%" PRIx64 "],%" PRId64 ") ", opname, dwarf_dieoffset (&impl_die), expr->number2); if (dwarf_whatattr (&attrval) == DW_AT_const_value) printf ("<constant value>"); // Lookup type... else { // Lookup the location description at the current address. Dwarf_Op *exprval; size_t exprval_len; int locs = dwarf_getlocation_addr (&attrval, addr, &exprval, &exprval_len, 1); if (locs == 0) printf ("<no location>"); // This means "optimized out". else if (locs == 1) print_expr_block (&attrval, exprval, exprval_len, addr); else error (EXIT_FAILURE, 0, "dwarf_getlocation_addr attrval at addr 0x%" PRIx64 ", locs (%d): %s", addr, locs, dwarf_errmsg (-1)); } } break; case DW_OP_GNU_entry_value: /* Special, unsigned size plus expression block. All registers inside the block should be interpreted as they had on entering the function. dwarf_getlocation_attr will return an attribute containing the block as locexpr which can be retrieved with dwarf_getlocation. */ { Dwarf_Attribute entry_attr; if (dwarf_getlocation_attr (attr, expr, &entry_attr) != 0) error (EXIT_FAILURE, 0, "dwarf_getlocation_attr: %s", dwarf_errmsg (-1)); Dwarf_Op *entry_ops; size_t entry_len; if (dwarf_getlocation (&entry_attr, &entry_ops, &entry_len) != 0) error (EXIT_FAILURE, 0, "dwarf_getlocation for entry: %s", dwarf_errmsg (-1)); printf ("%s(%zd) ", opname, entry_len); print_expr_block (attr, entry_ops, entry_len, addr); } break; case DW_OP_GNU_parameter_ref: /* Special, unsigned CU relative DIE offset pointing to a DW_TAG_formal_parameter. The value that parameter had at the call site of the current function will be put on the DWARF stack. The value can be retrieved by finding the DW_TAG_GNU_call_site_parameter which has as DW_AT_abstract_origin the same formal parameter DIE. */ { Dwarf_Die param; if (dwarf_getlocation_die (attr, expr, ¶m) != 0) error (EXIT_FAILURE, 0, "dwarf_getlocation_die: %s", dwarf_errmsg (-1)); // XXX actually lookup DW_TAG_GNU_call_site_parameter printf ("%s[%" PRIx64 "]", opname, dwarf_dieoffset (¶m)); assert (expr->number == dwarf_cuoffset (¶m)); assert (dwarf_tag (¶m) == DW_TAG_formal_parameter); } break; case DW_OP_GNU_convert: case DW_OP_GNU_reinterpret: /* Special, unsigned CU relative DIE offset pointing to a DW_TAG_base_type. Pops a value, converts or reinterprets the value to the given type. When the argument is zero the value becomes untyped again. */ { Dwarf_Die type; Dwarf_Off off = expr->number; if (off != 0) { if (dwarf_getlocation_die (attr, expr, &type) != 0) error (EXIT_FAILURE, 0, "dwarf_getlocation_die: %s", dwarf_errmsg (-1)); off = dwarf_dieoffset (&type); assert (expr->number == dwarf_cuoffset (&type)); printf ("%s", opname); print_base_type (&type); } else printf ("%s[%" PRIu64 "]", opname, off); } break; case DW_OP_GNU_regval_type: /* Special, unsigned register number plus unsigned CU relative DIE offset pointing to a DW_TAG_base_type. */ { Dwarf_Die type; if (dwarf_getlocation_die (attr, expr, &type) != 0) error (EXIT_FAILURE, 0, "dwarf_getlocation_die: %s", dwarf_errmsg (-1)); assert (expr->number2 == dwarf_cuoffset (&type)); // XXX check size against base_type size? printf ("%s(reg%" PRIu64 ")", opname, expr->number); print_base_type (&type); } break; case DW_OP_GNU_deref_type: /* Special, unsigned size plus unsigned CU relative DIE offset pointing to a DW_TAG_base_type. */ { Dwarf_Die type; if (dwarf_getlocation_die (attr, expr, &type) != 0) error (EXIT_FAILURE, 0, "dwarf_getlocation_die: %s", dwarf_errmsg (-1)); assert (expr->number2 == dwarf_cuoffset (&type)); // XXX check size against base_type size? printf ("%s(%" PRIu64 ")", opname, expr->number); print_base_type (&type); } break; case DW_OP_GNU_const_type: /* Special, unsigned CU relative DIE offset pointing to a DW_TAG_base_type, an unsigned size length plus a block with the constant value. */ { Dwarf_Die type; if (dwarf_getlocation_die (attr, expr, &type) != 0) error (EXIT_FAILURE, 0, "dwarf_getlocation_die: %s", dwarf_errmsg (-1)); assert (expr->number == dwarf_cuoffset (&type)); Dwarf_Attribute const_attr; if (dwarf_getlocation_attr (attr, expr, &const_attr) != 0) error (EXIT_FAILURE, 0, "dwarf_getlocation_attr for type: %s", dwarf_errmsg (-1)); Dwarf_Block block; if (dwarf_formblock (&const_attr, &block) != 0) error (EXIT_FAILURE, 0, "dwarf_formblock for type: %s", dwarf_errmsg (-1)); printf ("%s", opname); print_base_type (&type); printf ("(%" PRIu64 ")[", block.length); for (size_t i = 0; i < block.length; i++) printf ("%02x", block.data[i]); printf("]"); } break; default: error (EXIT_FAILURE, 0, "unhandled opcode: DW_OP_%s (0x%x)", opname, atom); } } /* Get all variables and print their value expressions. */ static void print_varlocs (Dwarf_Die *funcdie) { // Display frame base for function if it exists. // Should be used for DW_OP_fbreg. has_frame_base = dwarf_hasattr (funcdie, DW_AT_frame_base); if (has_frame_base) { Dwarf_Attribute fb_attr; if (dwarf_attr (funcdie, DW_AT_frame_base, &fb_attr) == NULL) error (EXIT_FAILURE, 0, "dwarf_attr fb: %s", dwarf_errmsg (-1)); Dwarf_Op *fb_expr; size_t fb_exprlen; if (dwarf_getlocation (&fb_attr, &fb_expr, &fb_exprlen) == 0) { // Covers all of function. Dwarf_Addr entrypc; if (dwarf_entrypc (funcdie, &entrypc) != 0) error (EXIT_FAILURE, 0, "dwarf_entrypc: %s", dwarf_errmsg (-1)); printf (" frame_base: "); if (entrypc == 0) printf ("XXX zero address"); // XXX bad DWARF? else print_expr_block (&fb_attr, fb_expr, fb_exprlen, entrypc); printf ("\n"); } else { Dwarf_Addr base, start, end; ptrdiff_t off = 0; printf (" frame_base:\n"); while ((off = dwarf_getlocations (&fb_attr, off, &base, &start, &end, &fb_expr, &fb_exprlen)) > 0) { printf (" (%" PRIx64 ",%" PRIx64 ") ", start, end); print_expr_block (&fb_attr, fb_expr, fb_exprlen, start); printf ("\n"); } if (off < 0) error (EXIT_FAILURE, 0, "dwarf_getlocations fb: %s", dwarf_errmsg (-1)); } } else if (dwarf_tag (funcdie) == DW_TAG_inlined_subroutine) { // See whether the subprogram we are inlined into has a frame // base we should use. Dwarf_Die *scopes; int n = dwarf_getscopes_die (funcdie, &scopes); if (n <= 0) error (EXIT_FAILURE, 0, "dwarf_getscopes_die: %s", dwarf_errmsg (-1)); while (n-- > 0) if (dwarf_tag (&scopes[n]) == DW_TAG_subprogram && dwarf_hasattr (&scopes[n], DW_AT_frame_base)) { has_frame_base = true; break; } free (scopes); } if (! dwarf_haschildren (funcdie)) return; Dwarf_Die child; int res = dwarf_child (funcdie, &child); if (res < 0) error (EXIT_FAILURE, 0, "dwarf_child: %s", dwarf_errmsg (-1)); /* We thought there was a child, but the child list was actually empty. This isn't technically an error in the DWARF, but it is certainly non-optimimal. */ if (res == 1) return; do { int tag = dwarf_tag (&child); if (tag == DW_TAG_variable || tag == DW_TAG_formal_parameter) { const char *what = tag == DW_TAG_variable ? "variable" : "parameter"; print_die (&child, what, 2); if (dwarf_hasattr (&child, DW_AT_location)) { Dwarf_Attribute attr; if (dwarf_attr (&child, DW_AT_location, &attr) == NULL) error (EXIT_FAILURE, 0, "dwarf_attr: %s", dwarf_errmsg (-1)); Dwarf_Op *expr; size_t exprlen; if (dwarf_getlocation (&attr, &expr, &exprlen) == 0) { // Covers all ranges of the function. // Evaluate the expression block for each range. ptrdiff_t offset = 0; Dwarf_Addr base, begin, end; do { offset = dwarf_ranges (funcdie, offset, &base, &begin, &end); if (offset < 0) error (EXIT_FAILURE, 0, "dwarf_ranges: %s", dwarf_errmsg (-1)); if (offset > 0) { if (exprlen == 0) printf (" (%" PRIx64 ",%" PRIx64 ") <empty expression>\n", begin, end); else print_expr_block_addrs (&attr, begin, end, expr, exprlen); } } while (offset > 0); if (offset < 0) error (EXIT_FAILURE, 0, "dwarf_ranges: %s", dwarf_errmsg (-1)); } else { Dwarf_Addr base, begin, end; ptrdiff_t offset = 0; while ((offset = dwarf_getlocations (&attr, offset, &base, &begin, &end, &expr, &exprlen)) > 0) if (begin >= end) printf (" (%" PRIx64 ",%" PRIx64 ") <empty range>\n", begin, end); // XXX report? else { print_expr_block_addrs (&attr, begin, end, expr, exprlen); // Extra sanity check for dwarf_getlocation_addr // Must at least find one range for begin and end-1. Dwarf_Op *expraddr; size_t expraddr_len; int locs = dwarf_getlocation_addr (&attr, begin, &expraddr, &expraddr_len, 1); assert (locs == 1); locs = dwarf_getlocation_addr (&attr, end - 1, &expraddr, &expraddr_len, 1); assert (locs == 1); } if (offset < 0) error (EXIT_FAILURE, 0, "dwarf_getlocations: %s", dwarf_errmsg (-1)); } } else if (dwarf_hasattr (&child, DW_AT_const_value)) { printf (" <constant value>\n"); // Lookup type and print. } else { printf (" <no value>\n"); } } } while (dwarf_siblingof (&child, &child) == 0); } static int handle_instance (Dwarf_Die *funcdie, void *arg __attribute__ ((unused))) { print_die (funcdie, "inlined function", 1); print_varlocs (funcdie); return DWARF_CB_OK; } static int handle_function (Dwarf_Die *funcdie, void *arg __attribute__((unused))) { if (dwarf_func_inline (funcdie) > 0) { // abstract inline definition, find all inlined instances. // Note this is convenient for listing all instances together // so you can easily compare the location expressions describing // the variables and parameters, but it isn't very efficient // since it will walk the DIE tree multiple times. if (dwarf_func_inline_instances (funcdie, &handle_instance, NULL) != 0) error (EXIT_FAILURE, 0, "dwarf_func_inline_instances: %s", dwarf_errmsg (-1)); } else { // Contains actual code, not just a declaration? Dwarf_Addr entrypc; if (dwarf_entrypc (funcdie, &entrypc) == 0) { print_die (funcdie, "function", 1); print_varlocs (funcdie); } } return DWARF_CB_OK; } int main (int argc, char *argv[]) { int remaining; Dwfl *dwfl; (void) argp_parse (dwfl_standard_argp (), argc, argv, 0, &remaining, &dwfl); assert (dwfl != NULL); Dwarf_Die *cu = NULL; Dwarf_Addr dwbias; while ((cu = dwfl_nextcu (dwfl, cu, &dwbias)) != NULL) { /* Only walk actual compile units (not partial units) that contain code. */ Dwarf_Addr cubase; if (dwarf_tag (cu) == DW_TAG_compile_unit && dwarf_lowpc (cu, &cubase) == 0) { Dwfl_Module *mod = dwfl_cumodule (cu); Dwarf_Addr modbias; dw = dwfl_module_getdwarf (mod, &modbias); assert (dwbias == modbias); const char *mainfile; const char *modname = dwfl_module_info (mod, NULL, NULL, NULL, NULL, NULL, &mainfile, NULL); if (modname == NULL) error (EXIT_FAILURE, 0, "dwfl_module_info: %s", dwarf_errmsg (-1)); const char *name = (modname[0] != '\0' ? modname : basename (mainfile)); printf ("module '%s'\n", name); print_die (cu, "CU", 0); Dwarf_Addr elfbias; Elf *elf = dwfl_module_getelf (mod, &elfbias); // CFI. We need both since sometimes neither is complete. cfi_debug = dwarf_getcfi (dw); // No bias needed, same file. cfi_eh = dwarf_getcfi_elf (elf); cfi_eh_bias = dwbias - elfbias; // Get the actual CU DIE and walk all functions inside it. Dwarf_Die cudie; uint8_t offsize; uint8_t addrsize; if (dwarf_diecu (cu, &cudie, &addrsize, &offsize) == NULL) error (EXIT_FAILURE, 0, "dwarf_diecu %s", dwarf_errmsg (-1)); if (dwarf_getfuncs (cu, handle_function, NULL, 0) != 0) error (EXIT_FAILURE, 0, "dwarf_getfuncs %s", dwarf_errmsg (-1)); } } dwfl_end (dwfl); return 0; }