cpptrace/src/symbols/symbols_with_libdwarf.cpp

1115 lines
39 KiB
C++

#ifdef CPPTRACE_GET_SYMBOLS_WITH_LIBDWARF
#include <cpptrace/cpptrace.hpp>
#include "symbols.hpp"
#include "../platform/common.hpp"
#include "../platform/program_name.hpp"
#include "../platform/object.hpp"
#include "../platform/error.hpp"
#include "../platform/utils.hpp"
#include <cstdint>
#include <cstdio>
#include <functional>
#include <memory>
#include <mutex>
#include <type_traits>
#include <vector>
#include <libdwarf.h>
#include <dwarf.h>
// some stuff is based on https://github.com/davea42/libdwarf-addr2line/blob/master/addr2line.c, mainly line handling
// then much expanded for symbols and efficiency
// dwarf5_ranges and dwarf4_ranges utility functions are taken from there directly, also pc_in_die
// TODO
// Inlined calls
// Memoizing / lazy loading
// More utils to clean this up, some wrapper for unique_ptr
// Ensure memory is being cleaned up properly
// Efficiency tricks
// Implementation cleanup
// Properly get the image base
#define DW_PR_DUx "llx"
#define DW_PR_DUu "llu"
Dwarf_Unsigned get_ranges_offset(Dwarf_Attribute attr) {
Dwarf_Unsigned off = 0;
Dwarf_Half attrform = 0;
dwarf_whatform(attr, &attrform, nullptr);
if (attrform == DW_FORM_rnglistx) {
int fres = dwarf_formudata(attr, &off, nullptr);
CPPTRACE_VERIFY(fres == DW_DLV_OK);
} else {
int fres = dwarf_global_formref(attr, &off, nullptr);
CPPTRACE_VERIFY(fres == DW_DLV_OK);
}
return off;
}
static int dwarf5_ranges(Dwarf_Die cu_die, Dwarf_Addr *lowest, Dwarf_Addr *highest) {
Dwarf_Unsigned offset = 0;
Dwarf_Attribute attr = 0;
Dwarf_Half attrform = 0;
Dwarf_Unsigned i = 0;
int res = 0;
res = dwarf_attr(cu_die, DW_AT_ranges, &attr, nullptr);
if(res != DW_DLV_OK) {
return res;
}
offset = get_ranges_offset(attr);
if(true) {
Dwarf_Unsigned rlesetoffset = 0;
Dwarf_Unsigned rnglists_count = 0;
Dwarf_Rnglists_Head head = 0;
dwarf_whatform(attr, &attrform, nullptr);
/* offset is in .debug_rnglists */
res = dwarf_rnglists_get_rle_head(
attr,
attrform,
offset,
&head,
&rnglists_count,
&rlesetoffset,
nullptr
);
CPPTRACE_VERIFY(res == DW_DLV_OK);
if(res != DW_DLV_OK) {
/* ASSERT: is DW_DLV_NO_ENTRY */
dwarf_dealloc_attribute(attr);
return res;
}
for( ; i < rnglists_count; ++i) {
unsigned entrylen = 0;
unsigned rle_val = 0;
Dwarf_Unsigned raw1 = 0;
Dwarf_Unsigned raw2 = 0;
Dwarf_Bool unavail = 0;
Dwarf_Unsigned cooked1 = 0;
Dwarf_Unsigned cooked2 = 0;
res = dwarf_get_rnglists_entry_fields_a(
head,
i,
&entrylen,
&rle_val,
&raw1,
&raw2,
&unavail,
&cooked1,
&cooked2,
nullptr
);
if(res != DW_DLV_OK) {
/* ASSERT: is DW_DLV_NO_ENTRY */
continue;
}
if(unavail) {
continue;
}
switch(rle_val) {
case DW_RLE_end_of_list:
case DW_RLE_base_address:
case DW_RLE_base_addressx:
/* These are accounted for already */
break;
case DW_RLE_offset_pair:
case DW_RLE_startx_endx:
case DW_RLE_start_end:
case DW_RLE_startx_length:
case DW_RLE_start_length:
if(cooked1 < *lowest) {
*lowest = cooked1;
}
if(cooked2 > *highest) {
*highest = cooked2;
}
break;
default:
CPPTRACE_VERIFY(false);
/* Something is wrong. */
break;
}
}
dwarf_dealloc_rnglists_head(head);
}
dwarf_dealloc_attribute(attr);
return DW_DLV_OK;
}
static int dwarf4_ranges(
Dwarf_Debug dbg,
Dwarf_Die cu_die,
Dwarf_Addr cu_lowpc,
Dwarf_Addr *lowest,
Dwarf_Addr *highest
) {
Dwarf_Unsigned offset;
Dwarf_Attribute attr = 0;
int res = 0;
res = dwarf_attr(cu_die, DW_AT_ranges, &attr, nullptr);
if(res != DW_DLV_OK) {
return res;
}
if(dwarf_global_formref(attr, &offset, nullptr) == DW_DLV_OK) {
Dwarf_Signed count = 0;
Dwarf_Ranges *ranges = 0;
Dwarf_Addr baseaddr = 0;
if(cu_lowpc != 0xffffffffffffffff) {
baseaddr = cu_lowpc;
}
res = dwarf_get_ranges_b(
dbg,
offset,
cu_die,
nullptr,
&ranges,
&count,
nullptr,
nullptr
);
for(int i = 0; i < count; i++) {
Dwarf_Ranges *cur = ranges + i;
if(cur->dwr_type == DW_RANGES_ENTRY) {
Dwarf_Addr rng_lowpc, rng_highpc;
rng_lowpc = baseaddr + cur->dwr_addr1;
rng_highpc = baseaddr + cur->dwr_addr2;
if(rng_lowpc < *lowest) {
*lowest = rng_lowpc;
}
if(rng_highpc > *highest) {
*highest = rng_highpc;
}
} else if(cur->dwr_type ==
DW_RANGES_ADDRESS_SELECTION) {
baseaddr = cur->dwr_addr2;
} else { // DW_RANGES_END
baseaddr = cu_lowpc;
}
}
dwarf_dealloc_ranges(dbg, ranges, count);
}
dwarf_dealloc_attribute(attr);
return DW_DLV_OK;
}
namespace cpptrace {
namespace detail {
namespace libdwarf {
// printbugging as we go
constexpr bool dump_dwarf = false;
constexpr bool trace_dwarf = false;
static void err_handler(Dwarf_Error err, Dwarf_Ptr errarg) {
printf("libdwarf error reading %s: %lu %s\n", "xx", (unsigned long)dwarf_errno(err), dwarf_errmsg(err));
if(errarg) {
printf("Error: errarg is nonnull but it should be null\n");
}
printf("Giving up");
exit(1);
}
static void print_line(Dwarf_Debug dbg, Dwarf_Line line, Dwarf_Addr pc, stacktrace_frame& frame) {
char what[] = "??";
char * linesrc = what;
Dwarf_Unsigned lineno = 0;
(void)pc;
if(line) {
/* These never return DW_DLV_NO_ENTRY */
dwarf_linesrc(line, &linesrc, nullptr);
dwarf_lineno(line, &lineno, nullptr);
}
if(dump_dwarf) {
printf("%s:%" DW_PR_DUu "\n", linesrc, lineno);
}
frame.line = static_cast<uint_least32_t>(lineno);
frame.filename = linesrc;
if(line) {
dwarf_dealloc(dbg, linesrc, DW_DLA_STRING);
}
}
static_assert(std::is_pointer<Dwarf_Die>::value, "Dwarf_Die not a pointer");
static_assert(std::is_pointer<Dwarf_Debug>::value, "Dwarf_Debug not a pointer");
struct die_object {
Dwarf_Debug dbg = nullptr;
Dwarf_Die die = nullptr;
die_object(Dwarf_Debug dbg, Dwarf_Die die) : dbg(dbg), die(die) {}
~die_object() {
if(die) {
dwarf_dealloc(dbg, die, DW_DLA_DIE);
}
}
die_object(const die_object&) = delete;
die_object& operator=(const die_object&) = delete;
die_object(die_object&& other) : dbg(other.dbg), die(other.die) {
other.die = nullptr;
}
die_object& operator=(die_object&& other) {
dbg = other.dbg;
die = other.die;
other.die = nullptr;
return *this;
}
die_object get_child() const {
Dwarf_Die child = nullptr;
int ret = dwarf_child(
die,
&child,
nullptr
);
if(ret == DW_DLV_OK) {
return die_object(dbg, child);
} else if(ret == DW_DLV_NO_ENTRY) {
return die_object(dbg, 0);
} else {
fprintf(stderr, "Error\n");
exit(1);
}
}
die_object get_sibling() const {
Dwarf_Die sibling = 0;
int ret = dwarf_siblingof_b(dbg, die, true, &sibling, nullptr);
if(ret == DW_DLV_OK) {
return die_object(dbg, sibling);
} else if(ret == DW_DLV_NO_ENTRY) {
return die_object(dbg, 0);
} else {
fprintf(stderr, "Error\n");
exit(1);
}
}
operator bool() const {
return die != nullptr;
}
Dwarf_Die get() const {
return die;
}
std::string get_name() const {
char empty[] = "";
char* name = empty;
int ret = dwarf_diename(die, &name, nullptr);
std::string str;
if(ret != DW_DLV_NO_ENTRY) {
str = name;
dwarf_dealloc(dbg, name, DW_DLA_STRING);
}
return name;
}
optional<std::string> get_string_attribute(Dwarf_Half dw_attrnum) const {
Dwarf_Attribute attr;
int ret = dwarf_attr(die, dw_attrnum, &attr, nullptr);
if(ret == DW_DLV_OK) {
char* raw_str;
std::string str;
ret = dwarf_formstring(attr, &raw_str, nullptr);
CPPTRACE_VERIFY(ret == DW_DLV_OK);
str = raw_str;
dwarf_dealloc(dbg, raw_str, DW_DLA_STRING);
dwarf_dealloc_attribute(attr);
return str;
} else {
return nullopt;
}
}
bool has_attr(Dwarf_Half dw_attrnum) const {
Dwarf_Attribute attr;
int ret = dwarf_attr(die, dw_attrnum, &attr, nullptr);
if(ret == DW_DLV_NO_ENTRY) {
return false;
} else if(ret == DW_DLV_OK) {
// TODO: Better impl that doesn't require allocation....?
dwarf_dealloc_attribute(attr);
return true;
} else {
fprintf(stderr, "Error\n");
exit(1);
}
}
Dwarf_Half get_tag() const {
Dwarf_Half tag = 0;
dwarf_tag(die, &tag, nullptr);
return tag;
}
const char* get_tag_name() const {
const char* tag_name;
dwarf_get_TAG_name(get_tag(), &tag_name);
return tag_name;
}
Dwarf_Off get_global_offset() const {
Dwarf_Off off;
int ret = dwarf_dieoffset(die, &off, nullptr);
CPPTRACE_VERIFY(ret == DW_DLV_OK);
return off;
}
die_object resolve_reference_attribute(Dwarf_Half dw_attrnum) const {
Dwarf_Attribute attr;
int ret = dwarf_attr(die, dw_attrnum, &attr, nullptr);
Dwarf_Half form = 0;
ret = dwarf_whatform(attr, &form, nullptr);
switch(form) {
case DW_FORM_ref1:
case DW_FORM_ref2:
case DW_FORM_ref4:
case DW_FORM_ref8:
case DW_FORM_ref_udata:
{
Dwarf_Off off = 0;
Dwarf_Bool is_info = dwarf_get_die_infotypes_flag(die);
ret = dwarf_formref(attr, &off, &is_info, nullptr);
CPPTRACE_VERIFY(ret == DW_DLV_OK);
Dwarf_Off goff = 0;
ret = dwarf_convert_to_global_offset(attr, off, &goff, nullptr);
CPPTRACE_VERIFY(ret == DW_DLV_OK);
Dwarf_Die targ_die_a = 0;
ret = dwarf_offdie_b(dbg, goff, is_info, &targ_die_a, nullptr);
CPPTRACE_VERIFY(ret == DW_DLV_OK);
dwarf_dealloc_attribute(attr);
return die_object(dbg, targ_die_a);
}
case DW_FORM_ref_addr:
{
Dwarf_Off off;
ret = dwarf_global_formref(attr, &off, nullptr);
int is_info_a = dwarf_get_die_infotypes_flag(die);
Dwarf_Die targ_die_a = 0;
ret = dwarf_offdie_b(dbg, off, is_info_a, &targ_die_a, nullptr);
CPPTRACE_VERIFY(ret == DW_DLV_OK);
dwarf_dealloc_attribute(attr);
return die_object(dbg, targ_die_a);
}
case DW_FORM_ref_sig8:
{
Dwarf_Sig8 signature;
ret = dwarf_formsig8(attr, &signature, nullptr);
CPPTRACE_VERIFY(ret == DW_DLV_OK);
Dwarf_Die targdie = 0;
Dwarf_Bool targ_is_info = false;
ret = dwarf_find_die_given_sig8(dbg, &signature, &targdie, &targ_is_info, nullptr);
CPPTRACE_VERIFY(ret == DW_DLV_OK);
dwarf_dealloc_attribute(attr);
return die_object(dbg, targdie);
}
default:
fprintf(stderr, "unknown form for attribute %d %d\n", dw_attrnum, form);
exit(1);
}
}
};
bool is_mangled_name(const std::string& name) {
return name.find("_Z") || name.find("?h@@");
}
struct line_context {
Dwarf_Unsigned version;
Dwarf_Small table_count;
Dwarf_Line_Context ctx;
};
struct dwarf_resolver {
std::string obj_path;
Dwarf_Debug dbg;
std::unordered_map<Dwarf_Off, line_context> line_contexts;
CPPTRACE_FORCE_NO_INLINE
dwarf_resolver(const std::string& object_path) {
obj_path = object_path;
#if IS_APPLE
if(directory_exists(obj_path + ".dSYM")) {
obj_path += ".dSYM/Contents/Resources/DWARF/" + basename(object_path);
}
#endif
Dwarf_Ptr errarg = 0;
auto ret = dwarf_init_path(
obj_path.c_str(),
nullptr,
0,
DW_GROUPNUMBER_ANY,
err_handler,
errarg,
&dbg,
nullptr
);
if(ret == DW_DLV_NO_ENTRY) {
// fail, no debug info
} else if(ret != DW_DLV_OK) {
fprintf(stderr, "Error\n");
} else {
}
}
CPPTRACE_FORCE_NO_INLINE
~dwarf_resolver() {
dwarf_finish(dbg);
for(auto& entry : line_contexts) {
dwarf_srclines_dealloc_b(entry.second.ctx);
}
}
Dwarf_Bool pc_in_die(Dwarf_Die die, int version, Dwarf_Addr pc) {
int ret;
Dwarf_Addr cu_lowpc = 0xffffffffffffffff;
Dwarf_Addr cu_highpc = 0;
enum Dwarf_Form_Class highpc_cls;
Dwarf_Addr lowest = 0xffffffffffffffff;
Dwarf_Addr highest = 0;
ret = dwarf_lowpc(die, &cu_lowpc, nullptr);
if(ret == DW_DLV_OK) {
if(pc == cu_lowpc) {
return true;
}
ret = dwarf_highpc_b(die, &cu_highpc,
nullptr, &highpc_cls, nullptr);
if(ret == DW_DLV_OK) {
if(highpc_cls == DW_FORM_CLASS_CONSTANT) {
cu_highpc += cu_lowpc;
}
if(pc >= cu_lowpc && pc < cu_highpc) {
return true;
}
}
}
if(version >= 5) {
ret = dwarf5_ranges(die, &lowest, &highest);
} else {
ret = dwarf4_ranges(dbg, die, cu_lowpc, &lowest, &highest);
}
if(pc >= lowest && pc < highest) {
return true;
}
return false;
}
// walk die list, callback is called on each die and should return true to
// continue traversal
void walk_die_list(
const die_object& die,
std::function<bool(const die_object&)> fn
) {
// TODO: Refactor so there is only one fn call
if(fn(die)) {
die_object current = die.get_sibling();
while(current) {
if(fn(current)) {
current = current.get_sibling();
} else {
break;
}
}
}
if(dump_dwarf) {
fprintf(stderr, "End walk_die_list\n");
}
}
// walk die list, recursing into children, callback is called on each die
// and should return true to continue traversal
// returns true if traversal should continue
bool walk_die_list_recursive(
const die_object& die,
std::function<bool(const die_object&)> fn
) {
bool continue_traversal = true;
walk_die_list(
die,
[this, &fn, &continue_traversal](const die_object& die) {
auto child = die.get_child();
if(child) {
if(!walk_die_list_recursive(child, fn)) {
continue_traversal = false;
return false;
}
}
return fn(die);
}
);
return continue_traversal;
}
void retrieve_symbol_for_subprogram(
const die_object& die,
Dwarf_Addr pc,
Dwarf_Half dwversion,
stacktrace_frame& frame
) {
CPPTRACE_VERIFY(die.get_tag() == DW_TAG_subprogram);
optional<std::string> name;
if(auto linkage_name = die.get_string_attribute(DW_AT_linkage_name)) {
name = std::move(linkage_name);
} else if(auto linkage_name = die.get_string_attribute(DW_AT_MIPS_linkage_name)) {
name = std::move(linkage_name);
} else if(auto linkage_name = die.get_string_attribute(DW_AT_name)) {
name = std::move(linkage_name);
}
if(name) {
frame.symbol = std::move(name).unwrap();
} else {
if(die.has_attr(DW_AT_specification)) {
die_object spec = die.resolve_reference_attribute(DW_AT_specification);
// TODO: Passing pc here is misleading
return retrieve_symbol_for_subprogram(spec, pc, dwversion, frame);
}
}
// TODO: Disabled for now
// TODO: Handle namespaces
/*std::string name = die.get_name();
std::vector<std::string> params;
auto child = die.get_child();
if(child) {
walk_die_list_recursive(
dbg,
child,
[pc, dwversion, &frame, &params] (Dwarf_Debug dbg, const die_object& die) {
if(die.get_tag() == DW_TAG_formal_parameter) {
// TODO: Ignore DW_AT_artificial
params.push_back(resolve_type(dbg, get_type_die(dbg, die)));
}
}
);
} else {
fprintf(stderr, "no child %s\n", name.c_str());
}
frame.symbol = name + "(" + join(params, ", ") + ")";*/
}
// returns true if this call found the symbol
CPPTRACE_FORCE_NO_INLINE
bool retrieve_symbol(
const die_object& die,
Dwarf_Addr pc,
Dwarf_Half dwversion,
stacktrace_frame& frame
) {
bool found = false;
walk_die_list(
die,
[this, pc, dwversion, &frame, &found] (const die_object& die) {
if(dump_dwarf) {
fprintf(
stderr,
"-------------> %08llx %s %s\n",
(unsigned long long) die.get_global_offset(),
die.get_tag_name(),
die.get_name().c_str()
);
}
if(!(die.get_tag() == DW_TAG_namespace || pc_in_die(die.get(), dwversion, pc))) {
if(dump_dwarf) {
fprintf(stderr, "pc not in die\n");
}
} else {
if(trace_dwarf) {
fprintf(
stderr,
"%s %08llx %s\n",
die.get_tag() == DW_TAG_namespace ? "pc maybe in die (namespace)" : "pc in die",
(unsigned long long) die.get_global_offset(),
die.get_tag_name()
);
}
if(die.get_tag() == DW_TAG_subprogram) {
retrieve_symbol_for_subprogram(die, pc, dwversion, frame);
found = true;
return false;
}
auto child = die.get_child();
if(child) {
if(retrieve_symbol(child, pc, dwversion, frame)) {
found = true;
return false;
}
} else {
if(dump_dwarf) {
fprintf(stderr, "(no child)\n");
}
}
}
return true;
}
);
return found;
}
CPPTRACE_FORCE_NO_INLINE
void retrieve_line_info(
const die_object& die,
Dwarf_Addr pc,
Dwarf_Half dwversion,
stacktrace_frame& frame
) {
Dwarf_Unsigned version;
Dwarf_Small table_count;
Dwarf_Line_Context ctxt;
Dwarf_Bool is_found = false;
(void)dwversion;
auto off = die.get_global_offset();
auto it = line_contexts.find(off);
if(it != line_contexts.end()) {
auto& entry = it->second;
version = entry.version;
table_count = entry.table_count;
ctxt = entry.ctx;
} else {
int ret = dwarf_srclines_b(
die.get(),
&version,
&table_count,
&ctxt,
nullptr
);
line_contexts.insert({off, {version, table_count, ctxt}});
if(ret == DW_DLV_NO_ENTRY) {
fprintf(stderr, "dwarf_srclines_b error\n");
return;
}
}
if(table_count == 1) {
Dwarf_Line *linebuf = 0;
Dwarf_Signed linecount = 0;
Dwarf_Addr prev_lineaddr = 0;
dwarf_srclines_from_linecontext(ctxt, &linebuf,
&linecount, nullptr);
Dwarf_Line prev_line = 0;
for(int i = 0; i < linecount; i++) {
Dwarf_Line line = linebuf[i];
Dwarf_Addr lineaddr = 0;
dwarf_lineaddr(line, &lineaddr, nullptr);
if(pc == lineaddr) {
/* Print the last line entry containing current pc. */
Dwarf_Line last_pc_line = line;
for(int j = i + 1; j < linecount; j++) {
Dwarf_Line j_line = linebuf[j];
dwarf_lineaddr(j_line, &lineaddr, nullptr);
if(pc == lineaddr) {
last_pc_line = j_line;
}
}
is_found = true;
print_line(dbg, last_pc_line, pc, frame);
break;
} else if(prev_line && pc > prev_lineaddr &&
pc < lineaddr) {
is_found = true;
print_line(dbg, prev_line, pc, frame);
break;
}
Dwarf_Bool is_lne;
dwarf_lineendsequence(line, &is_lne, nullptr);
if(is_lne) {
prev_line = 0;
} else {
prev_lineaddr = lineaddr;
prev_line = line;
}
}
}
}
CPPTRACE_FORCE_NO_INLINE
void walk_compilation_units(Dwarf_Addr pc, stacktrace_frame& frame) {
// 0 passed as the die to the first call of dwarf_siblingof_b immediately after dwarf_next_cu_header_d
// to fetch the cu die
die_object cu_die(dbg, nullptr);
cu_die = cu_die.get_sibling();
if(!cu_die) {
if(dump_dwarf) {
fprintf(stderr, "End walk_compilation_units\n");
}
return;
}
walk_die_list(
cu_die,
[this, &frame, pc] (const die_object& cu_die) {
Dwarf_Half offset_size = 0;
Dwarf_Half dwversion = 0;
dwarf_get_version_of_die(cu_die.get(), &dwversion, &offset_size);
if(trace_dwarf) {
fprintf(stderr, "CU: %d %s\n", dwversion, cu_die.get_name().c_str());
}
if(pc_in_die(cu_die.get(), dwversion, pc)) {
if(trace_dwarf) {
fprintf(
stderr,
"pc in die %08llx %s (now searching for %08llx)\n",
(unsigned long long) cu_die.get_global_offset(),
cu_die.get_tag_name(),
pc
);
}
retrieve_line_info(cu_die, pc, dwversion, frame); // no offset for line info
retrieve_symbol(cu_die, pc, dwversion, frame);
return false;
}
return true;
}
);
}
CPPTRACE_FORCE_NO_INLINE
void walk_dbg(Dwarf_Addr pc, stacktrace_frame& frame) {
// libdwarf keeps track of where it is in the file, dwarf_next_cu_header_d is statefull
Dwarf_Unsigned next_cu_header;
Dwarf_Half header_cu_type;
while(true) {
int ret = dwarf_next_cu_header_d(
dbg,
true,
nullptr,
nullptr,
nullptr,
nullptr,
nullptr,
nullptr,
nullptr,
nullptr,
&next_cu_header,
&header_cu_type,
nullptr
);
if(ret == DW_DLV_NO_ENTRY) {
if(dump_dwarf) {
fprintf(stderr, "End walk_dbg\n");
}
return;
}
if(ret != DW_DLV_OK) {
fprintf(stderr, "Error\n");
return;
}
walk_compilation_units(pc, frame);
}
}
CPPTRACE_FORCE_NO_INLINE
void lookup_pc(
Dwarf_Addr pc,
stacktrace_frame& frame
) {
if(dump_dwarf) {
fprintf(stderr, "%s\n", obj_path.c_str());
fprintf(stderr, "%llx\n", pc);
}
walk_dbg(pc, frame);
}
CPPTRACE_FORCE_NO_INLINE
stacktrace_frame resolve_frame(const dlframe& frame_info) {
stacktrace_frame frame{};
frame.filename = frame_info.obj_path;
frame.symbol = frame_info.symbol;
frame.address = frame_info.raw_address;
if(trace_dwarf) {
fprintf(
stderr,
"Starting resolution for %s %08llx %s\n",
obj_path.c_str(),
(unsigned long long)frame_info.obj_address,
frame_info.symbol.c_str()
);
}
lookup_pc(
frame_info.obj_address,
frame
);
return frame;
}
};
CPPTRACE_FORCE_NO_INLINE
std::vector<stacktrace_frame> resolve_frames(const std::vector<void*>& frames) {
std::vector<stacktrace_frame> trace(frames.size(), stacktrace_frame { 0, 0, 0, "", "" });
const auto dlframes = get_frames_object_info(frames);
for(const auto& obj_entry : collate_frames(dlframes, trace)) {
const auto& obj_name = obj_entry.first;
dwarf_resolver resolver(obj_name);
for(const auto& entry : obj_entry.second) {
const auto& dlframe = entry.first.get();
auto& frame = entry.second.get();
frame = resolver.resolve_frame(dlframe);
}
}
return trace;
}
// Currently commented out. Need to decide if this is worth it. The mangled name is easier and maybe more
// trustworthy. This is a lot of effort for something that would only be relevant for extern "C" methods.
/*die_object get_type_die(Dwarf_Debug dbg, const die_object& die) {
Dwarf_Off type_offset;
Dwarf_Bool is_info;
int ret = dwarf_dietype_offset(die.get(), &type_offset, &is_info, nullptr);
if(ret == DW_DLV_OK) {
Dwarf_Die type_die;
ret = dwarf_offdie_b(
dbg,
type_offset,
is_info,
&type_die,
nullptr
);
if(ret == DW_DLV_OK) {
return die_object(dbg, type_die);
} else {
fprintf(stderr, "Error\n");
exit(1);
}
} else {
fprintf(stderr, "no type offset??\n");
}
return die_object(dbg, nullptr);
}
bool has_type(Dwarf_Debug dbg, const die_object& die) {
Dwarf_Attribute attr;
int ret = dwarf_attr(die.get(), DW_AT_type, &attr, nullptr);
if(ret == DW_DLV_NO_ENTRY) {
return false;
} else if(ret == DW_DLV_OK) {
dwarf_dealloc_attribute(attr);
return true;
} else {
fprintf(stderr, "Error\n");
exit(1);
}
}
struct type_result {
std::string base;
std::string extent;
std::string get_type() {
return base + extent;
}
};
// TODO: ::*, namespace lookup, arrays
// DW_TAG_namespace
const char* tag_to_keyword(Dwarf_Half tag) {
switch(tag) {
case DW_TAG_atomic_type:
return "_Atomic";
case DW_TAG_const_type:
return "const";
case DW_TAG_volatile_type:
return "volatile";
case DW_TAG_restrict_type:
return "restrict";
default:
{
const char* tag_name = nullptr;
dwarf_get_TAG_name(tag, &tag_name);
fprintf(stderr, "tag_to_keyword unknown tag %s\n", tag_name);
exit(1);
}
}
}
const char* tag_to_ptr_ref(Dwarf_Half tag) {
switch(tag) {
case DW_TAG_pointer_type:
return "*";
case DW_TAG_ptr_to_member_type:
return "::*"; // TODO
case DW_TAG_reference_type:
return "&";
case DW_TAG_rvalue_reference_type:
return "&&";
default:
{
const char* tag_name = nullptr;
dwarf_get_TAG_name(tag, &tag_name);
fprintf(stderr, "tag_to_ptr_ref unknown tag %s\n", tag_name);
exit(1);
}
}
}
std::string resolve_type(Dwarf_Debug dbg, const die_object& die, std::string build = "");
std::string get_array_extents(Dwarf_Debug dbg, const die_object& die) {
CPPTRACE_VERIFY(die.get_tag() == DW_TAG_array_type);
std::string extents = "";
walk_die_list(dbg, die.get_child(), [&extents](Dwarf_Debug dbg, const die_object& subrange) {
if(subrange.get_tag() == DW_TAG_subrange_type) {
Dwarf_Attribute attr = 0;
int res = 0;
res = dwarf_attr(subrange.get(), DW_AT_upper_bound, &attr, nullptr);
if(res != DW_DLV_OK) {
fprintf(stderr, "Error\n");
return;
}
Dwarf_Half form;
res = dwarf_whatform(attr, &form, nullptr);
if(res != DW_DLV_OK) {
fprintf(stderr, "Error\n");
return;
}
//fprintf(stderr, "form: %d\n", form);
Dwarf_Unsigned val;
res = dwarf_formudata(attr, &val, nullptr);
if(res != DW_DLV_OK) {
fprintf(stderr, "Error\n");
return;
}
extents += "[" + std::to_string(val + 1) + "]";
dwarf_dealloc_attribute(attr);
} else {
fprintf(stderr, "unknown tag %s\n", subrange.get_tag_name());
}
});
return extents;
}
std::string get_parameters(Dwarf_Debug dbg, const die_object& die) {
CPPTRACE_VERIFY(die.get_tag() == DW_TAG_subroutine_type);
std::vector<std::string> params;
walk_die_list(dbg, die.get_child(), [&params](Dwarf_Debug dbg, const die_object& die) {
if(die.get_tag() == DW_TAG_formal_parameter) {
// TODO: Ignore DW_AT_artificial
params.push_back(resolve_type(dbg, get_type_die(dbg, die)));
}
});
return "(" + join(params, ", ") + ")";
}
std::string resolve_type(Dwarf_Debug dbg, const die_object& die, std::string build) {
switch(auto tag = die.get_tag()) {
case DW_TAG_base_type:
case DW_TAG_class_type:
case DW_TAG_structure_type:
case DW_TAG_union_type:
case DW_TAG_enumeration_type:
return die.get_name() + build;
case DW_TAG_typedef:
return resolve_type(dbg, get_type_die(dbg, die));
//case DW_TAG_subroutine_type:
// {
// // If there's no DW_AT_type then it's a void
// std::vector<std::string> params;
// // TODO: Code duplication with retrieve_symbol_for_subprogram?
// walk_die_list(dbg, die.get_child(), [&params] (Dwarf_Debug dbg, const die_object& die) {
// if(die.get_tag() == DW_TAG_formal_parameter) {
// // TODO: Ignore DW_AT_artificial
// params.push_back(resolve_type(dbg, get_type_die(dbg, die)));
// }
// });
// if(!has_type(dbg, die)) {
// return "void" + (build.empty() ? "" : "(" + build + ")") + "(" + join(params, ", ") + ")";
// } else {
// // resolving return type, building on build
// return resolve_type(
// dbg, get_type_die(dbg, die),
// (build.empty() ? "" : "(" + build + ")")
// + "("
// + join(params, ", ")
// + ")"
// );
// }
// }
//case DW_TAG_array_type:
// return resolve_type(dbg, get_type_die(dbg, die), (build.empty() ? "" : "(" + build + ")") + "[" + "x" + "]");
case DW_TAG_pointer_type:
case DW_TAG_reference_type:
case DW_TAG_rvalue_reference_type:
case DW_TAG_ptr_to_member_type:
{
const auto child = get_type_die(dbg, die); // AST child, rather than dwarf child
const auto child_tag = child.get_tag();
switch(child_tag) {
case DW_TAG_subroutine_type:
if(!has_type(dbg, child)) {
return "void(" + std::string(tag_to_ptr_ref(tag)) + build + ")" + get_parameters(dbg, child);
} else {
return resolve_type(
dbg,
get_type_die(dbg, child),
"(" + std::string(tag_to_ptr_ref(tag)) + build + ")" + get_parameters(dbg, child)
);
}
case DW_TAG_array_type:
return resolve_type(
dbg,
get_type_die(dbg, child),
"(" + std::string(tag_to_ptr_ref(tag)) + build + ")" + get_array_extents(dbg, child)
);
default:
if(build.empty()) {
return resolve_type(dbg, get_type_die(dbg, die), tag_to_ptr_ref(tag));
} else {
return resolve_type(
dbg,
get_type_die(dbg, die),
std::string(tag_to_ptr_ref(tag)) + " " + build
);
}
}
}
case DW_TAG_const_type:
case DW_TAG_atomic_type:
case DW_TAG_volatile_type:
case DW_TAG_restrict_type:
{
const auto child = get_type_die(dbg, die); // AST child, rather than dwarf child
const auto child_tag = child.get_tag();
switch(child_tag) {
case DW_TAG_base_type:
case DW_TAG_class_type:
case DW_TAG_typedef:
return std::string(tag_to_keyword(tag))
+ " "
+ resolve_type(dbg, get_type_die(dbg, die), build);
default:
return resolve_type(
dbg,
get_type_die(dbg, die),
std::string(tag_to_keyword(tag)) + " " + build
);
}
}
default:
{
fprintf(stderr, "unknown tag %s\n", die.get_tag_name());
exit(1);
}
}
return {"<unknown>", "<unknown>"};
}*/
}
}
}
#endif