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Diffstat (limited to 'src/tests/varlocs.c')
| -rw-r--r-- | src/tests/varlocs.c | 826 |
1 files changed, 826 insertions, 0 deletions
diff --git a/src/tests/varlocs.c b/src/tests/varlocs.c new file mode 100644 index 00000000..04f17ff2 --- /dev/null +++ b/src/tests/varlocs.c @@ -0,0 +1,826 @@ +/* Test program for dwarf location functions. + Copyright (C) 2013 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 ONE_KNOWN_DW_ATE(NAME, CODE) [CODE] = #NAME, + ALL_KNOWN_DW_ATE +#undef 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; + 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 ONE_KNOWN_DW_OP_DESC(NAME, CODE, DESC) ONE_KNOWN_DW_OP (NAME, CODE) +#define ONE_KNOWN_DW_OP(NAME, CODE) [CODE] = #NAME, + ALL_KNOWN_DW_OP +#undef ONE_KNOWN_DW_OP +#undef ONE_KNOWN_DW_OP_DESC + }; + + 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; +} |