#include <cinttypes>
#include <cstdint>
-#include <algorithm>
#include <memory>
#include <utility>
+#include <boost/range/algorithm.hpp>
+
#include <fcntl.h>
#include <cstdlib>
#define DW_LANG_Objc DW_LANG_ObjC /* fix spelling error in older dwarf.h */
#include <dwarf.h>
#include <elfutils/libdw.h>
+#include <boost/algorithm/string/predicate.hpp>
+
#include <simgrid_config.h>
#include "src/simgrid/util.hpp"
#include <xbt/log.h>
*
* The default for a given language is defined in the DWARF spec.
*
- * \param language consant as defined by the DWARf spec
+ * \param language constant as defined by the DWARf spec
*/
static uint64_t MC_dwarf_default_lower_bound(int lang);
* \param info the resulting object fot the library/binary file (output)
* \param die the current DIE
* \param unit the DIE of the compile unit of the current DIE
- * \param frame containg frame if any
+ * \param frame containing frame if any
*/
static void MC_dwarf_handle_die(simgrid::mc::ObjectInformation* info, Dwarf_Die * die,
Dwarf_Die * unit, simgrid::mc::Frame* frame,
Dwarf_Die * unit, simgrid::mc::Frame* frame,
const char *ns);
-/** \brief Calls MC_dwarf_handle_die on all childrend of the given die
+/** \brief Calls MC_dwarf_handle_die on all children of the given die
*
* \param info the resulting object fot the library/binary file (output)
* \param die the current DIE
* \param unit the DIE of the compile unit of the current DIE
- * \param frame containg frame if any
+ * \param frame containing frame if any
*/
static void MC_dwarf_handle_children(simgrid::mc::ObjectInformation* info, Dwarf_Die * die,
Dwarf_Die * unit, simgrid::mc::Frame* frame,
* \param info the resulting object fot the library/binary file (output)
* \param die the current DIE
* \param unit the DIE of the compile unit of the current DIE
- * \param frame containg frame if any
+ * \param frame containing frame if any
*/
static void MC_dwarf_handle_variable_die(simgrid::mc::ObjectInformation* info, Dwarf_Die * die,
Dwarf_Die * unit, simgrid::mc::Frame* frame,
// TODO, we should use another type (because is is not a type but a member)
simgrid::mc::Member member;
- member.inheritance = tag == DW_TAG_inheritance;
+ if (tag == DW_TAG_inheritance)
+ member.flags |= simgrid::mc::Member::INHERITANCE_FLAG;
const char *name = MC_dwarf_attr_integrate_string(&child, DW_AT_name);
if (name)
member.name = name;
+ // Those base names are used by GCC and clang for virtual table pointers
+ // respectively ("__vptr$ClassName", "__vptr.ClassName"):
+ if (boost::algorithm::starts_with(member.name, "__vptr$") ||
+ boost::algorithm::starts_with(member.name, "__vptr."))
+ member.flags |= simgrid::mc::Member::VIRTUAL_POINTER_FLAG;
+ // A cleaner solution would be to check against the type:
+ // ---
+ // tag: DW_TAG_member
+ // name: "_vptr$Foo"
+ // type:
+ // # Type for a pointer to a vtable
+ // tag: DW_TAG_pointer_type
+ // type:
+ // # Type for a vtable:
+ // tag: DW_TAG_pointer_type
+ // name: "__vtbl_ptr_type"
+ // type:
+ // tag: DW_TAG_subroutine_type
+ // type:
+ // tag: DW_TAG_base_type
+ // name: "int"
+ // ---
+
member.byte_size =
MC_dwarf_attr_integrate_uint(&child, DW_AT_byte_size, 0);
member.type_id = MC_dwarf_at_type(&child);
break;
}
- return std::move(type);
+ return type;
}
static void MC_dwarf_handle_type_die(simgrid::mc::ObjectInformation* info, Dwarf_Die * die,
std::unique_ptr<simgrid::mc::Variable> variable =
std::unique_ptr<simgrid::mc::Variable>(new simgrid::mc::Variable());
- variable->dwarf_offset = dwarf_dieoffset(die);
+ variable->id = dwarf_dieoffset(die);
variable->global = frame == nullptr; // Can be override base on DW_AT_location
variable->object_info = info;
xbt_die(
"Could not read location expression in DW_AT_location "
"of variable <%" PRIx64 ">%s",
- (uint64_t) variable->dwarf_offset,
+ (uint64_t) variable->id,
variable->name.c_str());
}
if (len == 1 && expr[0].atom == DW_OP_addr) {
- variable->global = 1;
+ variable->global = true;
uintptr_t offset = (uintptr_t) expr[0].number;
uintptr_t base = (uintptr_t) info->base_address();
variable->address = (void *) (base + offset);
xbt_die("Unexpected form 0x%x (%i), class 0x%x (%i) list for location "
"in <%" PRIx64 ">%s",
form, form, (int) form_class, (int) form_class,
- (uint64_t) variable->dwarf_offset,
+ (uint64_t) variable->id,
variable->name.c_str());
}
variable->name =
"@anonymous#" + std::to_string(mc_anonymous_variable_index++);
- return std::move(variable);
+ return variable;
}
static void MC_dwarf_handle_variable_die(simgrid::mc::ObjectInformation* info, Dwarf_Die * die,
case simgrid::dwarf::FormClass::Address:
if (dwarf_formaddr(&attr, &high_pc) != 0)
xbt_die("Could not read address");
- frame.range.begin() = base + high_pc;
+ frame.range.end() = base + high_pc;
break;
default:
// We sort them in order to have an (somewhat) efficient by name
// lookup:
- std::sort(frame.variables.begin(), frame.variables.end(),
- MC_compare_variable);
+ boost::range::sort(frame.variables, MC_compare_variable);
// Register it:
if (klass == simgrid::dwarf::TagClass::Subprogram)
Dwarf_Off next_offset = 0;
size_t length;
- while (dwarf_nextcu(dwarf, offset, &next_offset, &length, nullptr, NULL, NULL) ==
+ while (dwarf_nextcu(dwarf, offset, &next_offset, &length, nullptr, nullptr, nullptr) ==
0) {
Dwarf_Die unit_die;
if (dwarf_offdie(dwarf, offset + length, &unit_die) != nullptr)
- MC_dwarf_handle_children(info, &unit_die, &unit_die, nullptr, NULL);
+ MC_dwarf_handle_children(info, &unit_die, &unit_die, nullptr, nullptr);
offset = next_offset;
}
}
static
std::vector<char> get_build_id(Elf* elf)
{
+ // Summary: the GNU build ID is stored in a ("GNU, NT_GNU_BUILD_ID) note
+ // found in a PT_NOTE entry in the program header table.
+
size_t phnum;
if (elf_getphdrnum (elf, &phnum) != 0)
xbt_die("Could not read program headers");
// Iterate over the notes and find the NT_GNU_BUILD_ID one:
size_t pos = 0;
- while (1) {
+ while (pos < data->d_size) {
GElf_Nhdr nhdr;
+ // Location of the name within Elf_Data:
size_t name_pos;
size_t desc_pos;
pos = gelf_getnote(data, pos, &nhdr, &name_pos, &desc_pos);
- // A note is identified by a name "GNU" and a integer type within
- // the namespace defined by this name (here NT_GNU_BUILD_ID):
+ // A build ID note is identified by the pair ("GNU", NT_GNU_BUILD_ID)
+ // (a namespace and a type within this namespace):
if (nhdr.n_type == NT_GNU_BUILD_ID
&& nhdr.n_namesz == sizeof("GNU")
&& memcmp((char*) data->d_buf + name_pos, "GNU", sizeof("GNU")) == 0) {
-
- // Found the NT_GNU_BUILD_ID note:
+ XBT_DEBUG("Found GNU/NT_GNU_BUILD_ID note");
char* start = (char*) data->d_buf + desc_pos;
char* end = (char*) start + nhdr.n_descsz;
return std::vector<char>(start, end);
-
}
}
for (int j = 0; j < 2; ++j)
res[2 * i + j] = hex_byte[j];
}
- return std::move(res);
+ return res;
}
/** Binary data to hexadecimal */
* This is one of the mechanisms used for
* [separate debug files](https://sourceware.org/gdb/onlinedocs/gdb/Separate-Debug-Files.html).
*/
+// Example:
+// /usr/lib/debug/.build-id/0b/dc77f1c29aea2b14ff5acd9a19ab3175ffdeae.debug
static
std::string find_by_build_id(std::vector<char> id)
{
std::string filename;
+ std::string hex = to_hex(id);
for (const char* debug_path : debug_paths) {
- filename = debug_path;
- filename += ".build-id/" + to_hex(id.data(), 1) + '/'
+ // Example:
+ filename = std::string(debug_path) + ".build-id/"
+ + to_hex(id.data(), 1) + '/'
+ to_hex(id.data() + 1, id.size() - 1) + ".debug";
XBT_DEBUG("Checking debug file: %s", filename.c_str());
- if (access(filename.c_str(), F_OK) == 0)
- return std::move(filename);
+ if (access(filename.c_str(), F_OK) == 0) {
+ XBT_DEBUG("Found debug file: %s\n", hex.c_str());
+ return filename;
+ }
}
+ XBT_DEBUG("Not debuf info found for build ID %s\n", hex.data());
return std::string();
}
* lists of types, variables, functions.
*/
static
-void MC_dwarf_get_variables(simgrid::mc::ObjectInformation* info)
+void MC_load_dwarf(simgrid::mc::ObjectInformation* info)
{
if (elf_version(EV_CURRENT) == EV_NONE)
xbt_die("libelf initialization error");
xbt_die("Could not open file %s", info->file_name.c_str());
Elf* elf = elf_begin(fd, ELF_C_READ, nullptr);
if (elf == nullptr)
- xbt_die("Not an ELF file 1");
+ xbt_die("Not an ELF file");
Elf_Kind kind = elf_kind(elf);
if (kind != ELF_K_ELF)
- xbt_die("Not an ELF file 2");
+ xbt_die("Not an ELF file");
- // Remember if this is a `ET_EXEC` (fixed location) or `ET_DYN` (relocatable):
+ // Remember if this is a `ET_EXEC` (fixed location) or `ET_DYN`:
Elf64_Half type = get_type(elf);
if (type == ET_EXEC)
info->flags |= simgrid::mc::ObjectInformation::Executable;
}
dwarf_end(dwarf);
- // If there was no DWARF in the file, try to find it in a separate file
- // with NT_GNU_BUILD_ID:
+ // If there was no DWARF in the file, try to find it in a separate file.
+ // Different methods might be used to store the DWARF informations:
+ // * GNU NT_GNU_BUILD_ID;
+ // * .gnu_debuglink.
+ // See https://sourceware.org/gdb/onlinedocs/gdb/Separate-Debug-Files.html
+ // for reference of what we are doing.
+
+ // Try with NT_GNU_BUILD_ID: we find the build ID in the ELF file and then
+ // use this ID to find the file in some known locations in the filesystem.
std::vector<char> build_id = get_build_id(elf);
if (!build_id.empty()) {
elf_end(elf);
std::string debug_file = find_by_build_id(build_id);
if (debug_file.empty()) {
std::string hex = to_hex(build_id);
- xbt_die(
- "Missing debug info for %s with build-id %s\n"
+ xbt_die("Missing debug info for %s with build-id %s\n"
"You might want to install the suitable debugging package.\n",
info->file_name.c_str(), hex.c_str());
}
return;
}
- // TODO, try to find DWARF info using debug-link.
- // Is this method really used anywhere?
+ // TODO, try to find DWARF info using .gnu_debuglink.
+ elf_end(elf);
+ close(fd);
xbt_die("Debugging information not found for %s\n"
"Try recompiling with -g\n",
info->file_name.c_str());
info->functions_index.shrink_to_fit();
// Sort the array by low_pc:
- std::sort(info->functions_index.begin(), info->functions_index.end(),
+ boost::range::sort(info->functions_index,
[](simgrid::mc::FunctionIndexEntry const& a,
simgrid::mc::FunctionIndexEntry const& b)
{
static void MC_post_process_variables(simgrid::mc::ObjectInformation* info)
{
// Someone needs this to be sorted but who?
- std::sort(info->global_variables.begin(), info->global_variables.end(),
- MC_compare_variable);
+ boost::range::sort(info->global_variables, MC_compare_variable);
for(simgrid::mc::Variable& variable : info->global_variables)
if (variable.type_id)
std::make_shared<simgrid::mc::ObjectInformation>();
result->file_name = name;
simgrid::mc::find_object_address(maps, result.get());
- MC_dwarf_get_variables(result.get());
+ MC_load_dwarf(result.get());
MC_post_process_variables(result.get());
MC_post_process_types(result.get());
for (auto& entry : result.get()->subprograms)
mc_post_process_scope(result.get(), &entry.second);
MC_make_functions_index(result.get());
- return std::move(result);
+ return result;
}
/*************************************************************************/
*
* DWARF and libunwind does not use the same convention for numbering the
* registers on some architectures. The function makes the necessary
- * convertion.
+ * conversion.
*/
int dwarf_register_to_libunwind(int dwarf_register)
{
// It seems for this arch, DWARF and libunwind agree in the numbering:
return dwarf_register;
#elif defined(__i386__)
- // Could't find the authoritative source of information for this.
+ // Couldn't find the authoritative source of information for this.
// This is inspired from http://source.winehq.org/source/dlls/dbghelp/cpu_i386.c#L517.
switch (dwarf_register) {
case 0:
