+++ /dev/null
-/* Copyright (c) 2008-2019. The SimGrid Team. All rights reserved. */
-
-/* This program is free software; you can redistribute it and/or modify it
- * under the terms of the license (GNU LGPL) which comes with this package. */
-
-#include "src/simgrid/util.hpp"
-#include "xbt/log.h"
-#include "xbt/string.hpp"
-#include "xbt/sysdep.h"
-#include <simgrid/config.h>
-
-#include "src/mc/inspect/ObjectInformation.hpp"
-#include "src/mc/inspect/Variable.hpp"
-#include "src/mc/inspect/mc_dwarf.hpp"
-#include "src/mc/mc_private.hpp"
-#include "src/mc/remote/RemoteClient.hpp"
-
-#include <cinttypes>
-#include <cstdint>
-#include <cstdlib>
-#include <fcntl.h>
-#include <memory>
-#include <utility>
-
-#include <boost/range/algorithm.hpp>
-
-#include <elfutils/libdw.h>
-
-#include <boost/algorithm/string/predicate.hpp>
-
-XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_dwarf, mc, "DWARF processing");
-
-/** @brief The default DW_TAG_lower_bound for a given DW_AT_language.
- *
- * The default for a given language is defined in the DWARF spec.
- *
- * @param language constant as defined by the DWARf spec
- */
-static uint64_t MC_dwarf_default_lower_bound(int lang);
-
-/** @brief Computes the the element_count of a DW_TAG_enumeration_type DIE
- *
- * This is the number of elements in a given array dimension.
- *
- * A reference of the compilation unit (DW_TAG_compile_unit) is
- * needed because the default lower bound (when there is no DW_AT_lower_bound)
- * depends of the language of the compilation unit (DW_AT_language).
- *
- * @param die DIE for the DW_TAG_enumeration_type or DW_TAG_subrange_type
- * @param unit DIE of the DW_TAG_compile_unit
- */
-static uint64_t MC_dwarf_subrange_element_count(Dwarf_Die* die, Dwarf_Die* unit);
-
-/** @brief Computes the number of elements of a given DW_TAG_array_type.
- *
- * @param die DIE for the DW_TAG_array_type
- */
-static uint64_t MC_dwarf_array_element_count(Dwarf_Die* die, Dwarf_Die* unit);
-
-/** @brief Process a 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 containing frame if any
- */
-static void MC_dwarf_handle_die(simgrid::mc::ObjectInformation* info, Dwarf_Die* die, Dwarf_Die* unit,
- simgrid::mc::Frame* frame, const char* ns);
-
-/** @brief Process a type DIE
- */
-static void MC_dwarf_handle_type_die(simgrid::mc::ObjectInformation* info, Dwarf_Die* die, Dwarf_Die* unit,
- simgrid::mc::Frame* frame, const char* ns);
-
-/** @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 containing frame if any
- */
-static void MC_dwarf_handle_children(simgrid::mc::ObjectInformation* info, Dwarf_Die* die, Dwarf_Die* unit,
- simgrid::mc::Frame* frame, const char* ns);
-
-/** @brief Handle a variable (DW_TAG_variable or other)
- *
- * @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 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, const char* ns);
-
-/** @brief Get the DW_TAG_type of the DIE
- *
- * @param die DIE
- * @return DW_TAG_type attribute as a new string (nullptr if none)
- */
-static std::uint64_t MC_dwarf_at_type(Dwarf_Die* die);
-
-namespace simgrid {
-namespace dwarf {
-
-enum class TagClass { Unknown, Type, Subprogram, Variable, Scope, Namespace };
-
-/*** Class of forms defined in the DWARF standard */
-enum class FormClass {
- Unknown,
- Address, // Location in the program's address space
- Block, // Arbitrary block of bytes
- Constant,
- String,
- Flag, // Boolean value
- Reference, // Reference to another DIE
- ExprLoc, // DWARF expression/location description
- LinePtr,
- LocListPtr,
- MacPtr,
- RangeListPtr
-};
-
-static TagClass classify_tag(int tag)
-{
- switch (tag) {
-
- case DW_TAG_array_type:
- case DW_TAG_class_type:
- case DW_TAG_enumeration_type:
- case DW_TAG_typedef:
- case DW_TAG_pointer_type:
- case DW_TAG_reference_type:
- case DW_TAG_rvalue_reference_type:
- case DW_TAG_string_type:
- case DW_TAG_structure_type:
- case DW_TAG_subroutine_type:
- case DW_TAG_union_type:
- case DW_TAG_ptr_to_member_type:
- case DW_TAG_set_type:
- case DW_TAG_subrange_type:
- case DW_TAG_base_type:
- case DW_TAG_const_type:
- case DW_TAG_file_type:
- case DW_TAG_packed_type:
- case DW_TAG_volatile_type:
- case DW_TAG_restrict_type:
- case DW_TAG_interface_type:
- case DW_TAG_unspecified_type:
- case DW_TAG_shared_type:
- return TagClass::Type;
-
- case DW_TAG_subprogram:
- return TagClass::Subprogram;
-
- case DW_TAG_variable:
- case DW_TAG_formal_parameter:
- return TagClass::Variable;
-
- case DW_TAG_lexical_block:
- case DW_TAG_try_block:
- case DW_TAG_catch_block:
- case DW_TAG_inlined_subroutine:
- case DW_TAG_with_stmt:
- return TagClass::Scope;
-
- case DW_TAG_namespace:
- return TagClass::Namespace;
-
- default:
- return TagClass::Unknown;
- }
-}
-
-/** @brief Find the DWARF data class for a given DWARF data form
- *
- * This mapping is defined in the DWARF spec.
- *
- * @param form The form (values taken from the DWARF spec)
- * @return An internal representation for the corresponding class
- * */
-static FormClass classify_form(int form)
-{
- switch (form) {
- case DW_FORM_addr:
- return FormClass::Address;
- case DW_FORM_block2:
- case DW_FORM_block4:
- case DW_FORM_block:
- case DW_FORM_block1:
- return FormClass::Block;
- case DW_FORM_data1:
- case DW_FORM_data2:
- case DW_FORM_data4:
- case DW_FORM_data8:
- case DW_FORM_udata:
- case DW_FORM_sdata:
- return FormClass::Constant;
- case DW_FORM_string:
- case DW_FORM_strp:
- return FormClass::String;
- case DW_FORM_ref_addr:
- case DW_FORM_ref1:
- case DW_FORM_ref2:
- case DW_FORM_ref4:
- case DW_FORM_ref8:
- case DW_FORM_ref_udata:
- return FormClass::Reference;
- case DW_FORM_flag:
- case DW_FORM_flag_present:
- return FormClass::Flag;
- case DW_FORM_exprloc:
- return FormClass::ExprLoc;
- // TODO sec offset
- // TODO indirect
- default:
- return FormClass::Unknown;
- }
-}
-
-/** @brief Get the name of the tag of a given DIE
- *
- * @param die DIE
- * @return name of the tag of this DIE
- */
-inline XBT_PRIVATE const char* tagname(Dwarf_Die* die)
-{
- return simgrid::dwarf::tagname(dwarf_tag(die));
-}
-
-} // namespace dwarf
-} // namespace simgrid
-
-// ***** Attributes
-
-/** @brief Get an attribute of a given DIE as a string
- *
- * @param die the DIE
- * @param attribute attribute
- * @return value of the given attribute of the given DIE
- */
-static const char* MC_dwarf_attr_integrate_string(Dwarf_Die* die, int attribute)
-{
- Dwarf_Attribute attr;
- if (not dwarf_attr_integrate(die, attribute, &attr))
- return nullptr;
- else
- return dwarf_formstring(&attr);
-}
-
-static Dwarf_Off MC_dwarf_attr_dieoffset(Dwarf_Die* die, int attribute)
-{
- Dwarf_Attribute attr;
- if (dwarf_hasattr_integrate(die, attribute) == 0)
- return 0;
- dwarf_attr_integrate(die, attribute, &attr);
- Dwarf_Die subtype_die;
- xbt_assert(dwarf_formref_die(&attr, &subtype_die) != nullptr, "Could not find DIE");
- return dwarf_dieoffset(&subtype_die);
-}
-
-static Dwarf_Off MC_dwarf_attr_integrate_dieoffset(Dwarf_Die* die, int attribute)
-{
- Dwarf_Attribute attr;
- if (dwarf_hasattr_integrate(die, attribute) == 0)
- return 0;
- dwarf_attr_integrate(die, DW_AT_type, &attr);
- Dwarf_Die subtype_die;
- xbt_assert(dwarf_formref_die(&attr, &subtype_die) != nullptr, "Could not find DIE");
- return dwarf_dieoffset(&subtype_die);
-}
-
-/** @brief Find the type/subtype (DW_AT_type) for a DIE
- *
- * @param die the DIE
- * @return DW_AT_type reference as a global offset in hexadecimal (or nullptr)
- */
-static std::uint64_t MC_dwarf_at_type(Dwarf_Die* die)
-{
- return MC_dwarf_attr_integrate_dieoffset(die, DW_AT_type);
-}
-
-static uint64_t MC_dwarf_attr_integrate_addr(Dwarf_Die* die, int attribute)
-{
- Dwarf_Attribute attr;
- if (dwarf_attr_integrate(die, attribute, &attr) == nullptr)
- return 0;
- Dwarf_Addr value;
- if (dwarf_formaddr(&attr, &value) == 0)
- return (uint64_t)value;
- else
- return 0;
-}
-
-static uint64_t MC_dwarf_attr_integrate_uint(Dwarf_Die* die, int attribute, uint64_t default_value)
-{
- Dwarf_Attribute attr;
- if (dwarf_attr_integrate(die, attribute, &attr) == nullptr)
- return default_value;
- Dwarf_Word value;
- return dwarf_formudata(dwarf_attr_integrate(die, attribute, &attr), &value) == 0 ? (uint64_t)value : default_value;
-}
-
-static bool MC_dwarf_attr_flag(Dwarf_Die* die, int attribute, bool integrate)
-{
- Dwarf_Attribute attr;
- if ((integrate ? dwarf_attr_integrate(die, attribute, &attr) : dwarf_attr(die, attribute, &attr)) == 0)
- return false;
-
- bool result;
- xbt_assert(not dwarf_formflag(&attr, &result), "Unexpected form for attribute %s",
- simgrid::dwarf::attrname(attribute));
- return result;
-}
-
-/** @brief Find the default lower bound for a given language
- *
- * The default lower bound of an array (when DW_TAG_lower_bound
- * is missing) depends on the language of the compilation unit.
- *
- * @param lang Language of the compilation unit (values defined in the DWARF spec)
- * @return Default lower bound of an array in this compilation unit
- * */
-static uint64_t MC_dwarf_default_lower_bound(int lang)
-{
- switch (lang) {
- case DW_LANG_C:
- case DW_LANG_C89:
- case DW_LANG_C99:
- case DW_LANG_C_plus_plus:
- case DW_LANG_D:
- case DW_LANG_Java:
- case DW_LANG_ObjC:
- case DW_LANG_ObjC_plus_plus:
- case DW_LANG_Python:
- case DW_LANG_UPC:
- return 0;
- case DW_LANG_Ada83:
- case DW_LANG_Ada95:
- case DW_LANG_Fortran77:
- case DW_LANG_Fortran90:
- case DW_LANG_Fortran95:
- case DW_LANG_Modula2:
- case DW_LANG_Pascal83:
- case DW_LANG_PL1:
- case DW_LANG_Cobol74:
- case DW_LANG_Cobol85:
- return 1;
- default:
- xbt_die("No default DW_TAG_lower_bound for language %i and none given", lang);
- return 0;
- }
-}
-
-/** @brief Finds the number of elements in a DW_TAG_subrange_type or DW_TAG_enumeration_type DIE
- *
- * @param die the DIE
- * @param unit DIE of the compilation unit
- * @return number of elements in the range
- * */
-static uint64_t MC_dwarf_subrange_element_count(Dwarf_Die* die, Dwarf_Die* unit)
-{
- xbt_assert(dwarf_tag(die) == DW_TAG_enumeration_type || dwarf_tag(die) == DW_TAG_subrange_type,
- "MC_dwarf_subrange_element_count called with DIE of type %s", simgrid::dwarf::tagname(die));
-
- // Use DW_TAG_count if present:
- if (dwarf_hasattr_integrate(die, DW_AT_count))
- return MC_dwarf_attr_integrate_uint(die, DW_AT_count, 0);
- // Otherwise compute DW_TAG_upper_bound-DW_TAG_lower_bound + 1:
-
- if (not dwarf_hasattr_integrate(die, DW_AT_upper_bound))
- // This is not really 0, but the code expects this (we do not know):
- return 0;
-
- uint64_t upper_bound = MC_dwarf_attr_integrate_uint(die, DW_AT_upper_bound, static_cast<uint64_t>(-1));
-
- uint64_t lower_bound = 0;
- if (dwarf_hasattr_integrate(die, DW_AT_lower_bound))
- lower_bound = MC_dwarf_attr_integrate_uint(die, DW_AT_lower_bound, static_cast<uint64_t>(-1));
- else
- lower_bound = MC_dwarf_default_lower_bound(dwarf_srclang(unit));
- return upper_bound - lower_bound + 1;
-}
-
-/** @brief Finds the number of elements in a array type (DW_TAG_array_type)
- *
- * The compilation unit might be needed because the default lower
- * bound depends on the language of the compilation unit.
- *
- * @param die the DIE of the DW_TAG_array_type
- * @param unit the DIE of the compilation unit
- * @return number of elements in this array type
- * */
-static uint64_t MC_dwarf_array_element_count(Dwarf_Die* die, Dwarf_Die* unit)
-{
- xbt_assert(dwarf_tag(die) == DW_TAG_array_type, "MC_dwarf_array_element_count called with DIE of type %s",
- simgrid::dwarf::tagname(die));
-
- int result = 1;
- Dwarf_Die child;
- int res;
- for (res = dwarf_child(die, &child); res == 0; res = dwarf_siblingof(&child, &child)) {
- int child_tag = dwarf_tag(&child);
- if (child_tag == DW_TAG_subrange_type || child_tag == DW_TAG_enumeration_type)
- result *= MC_dwarf_subrange_element_count(&child, unit);
- }
- return result;
-}
-
-// ***** Variable
-
-/** Sort the variable by name and address.
- *
- * We could use boost::container::flat_set instead.
- */
-static bool MC_compare_variable(simgrid::mc::Variable const& a, simgrid::mc::Variable const& b)
-{
- int cmp = a.name.compare(b.name);
- if (cmp < 0)
- return true;
- else if (cmp > 0)
- return false;
- else
- return a.address < b.address;
-}
-
-// ***** simgrid::mc::Type*
-
-/** @brief Initialize the location of a member of a type
- * (DW_AT_data_member_location of a DW_TAG_member).
- *
- * @param type a type (struct, class)
- * @param member the member of the type
- * @param child DIE of the member (DW_TAG_member)
- */
-static void MC_dwarf_fill_member_location(simgrid::mc::Type* type, simgrid::mc::Member* member, Dwarf_Die* child)
-{
- xbt_assert(not dwarf_hasattr(child, DW_AT_data_bit_offset), "Can't groke DW_AT_data_bit_offset.");
-
- if (not dwarf_hasattr_integrate(child, DW_AT_data_member_location)) {
- if (type->type == DW_TAG_union_type)
- return;
- xbt_die("Missing DW_AT_data_member_location field in DW_TAG_member %s of type <%" PRIx64 ">%s",
- member->name.c_str(), (uint64_t)type->id, type->name.c_str());
- }
-
- Dwarf_Attribute attr;
- dwarf_attr_integrate(child, DW_AT_data_member_location, &attr);
- int form = dwarf_whatform(&attr);
- simgrid::dwarf::FormClass form_class = simgrid::dwarf::classify_form(form);
- switch (form_class) {
- case simgrid::dwarf::FormClass::ExprLoc:
- case simgrid::dwarf::FormClass::Block:
- // Location expression:
- {
- Dwarf_Op* expr;
- size_t len;
- xbt_assert(not dwarf_getlocation(&attr, &expr, &len),
- "Could not read location expression DW_AT_data_member_location in DW_TAG_member %s of type <%" PRIx64
- ">%s",
- MC_dwarf_attr_integrate_string(child, DW_AT_name), (uint64_t)type->id, type->name.c_str());
- member->location_expression = simgrid::dwarf::DwarfExpression(expr, expr + len);
- break;
- }
- case simgrid::dwarf::FormClass::Constant:
- // Offset from the base address of the object:
- {
- Dwarf_Word offset;
- xbt_assert(not dwarf_formudata(&attr, &offset), "Cannot get %s location <%" PRIx64 ">%s",
- MC_dwarf_attr_integrate_string(child, DW_AT_name), (uint64_t)type->id, type->name.c_str());
- member->offset(offset);
- break;
- }
-
- default:
- // includes FormClass::LocListPtr (reference to a location list: TODO) and FormClass::Reference (it's supposed to
- // be possible in DWARF2 but I couldn't find its semantic in the spec)
- xbt_die("Can't handle form class (%d) / form 0x%x as DW_AT_member_location", (int)form_class, (unsigned)form);
- }
-}
-
-/** @brief Populate the list of members of a type
- *
- * @param info ELF object containing the type DIE
- * @param die DIE of the type
- * @param unit DIE of the compilation unit containing the type DIE
- * @param type the type
- */
-static void MC_dwarf_add_members(simgrid::mc::ObjectInformation* /*info*/, Dwarf_Die* die, Dwarf_Die* /*unit*/,
- simgrid::mc::Type* type)
-{
- int res;
- Dwarf_Die child;
- xbt_assert(type->members.empty());
- for (res = dwarf_child(die, &child); res == 0; res = dwarf_siblingof(&child, &child)) {
- int tag = dwarf_tag(&child);
- if (tag == DW_TAG_member || tag == DW_TAG_inheritance) {
-
- // Skip declarations:
- if (MC_dwarf_attr_flag(&child, DW_AT_declaration, false))
- continue;
-
- // Skip compile time constants:
- if (dwarf_hasattr(&child, DW_AT_const_value))
- continue;
-
- // TODO, we should use another type (because is is not a type but a member)
- simgrid::mc::Member member;
- 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);
-
- xbt_assert(not dwarf_hasattr(&child, DW_AT_data_bit_offset), "Can't groke DW_AT_data_bit_offset.");
-
- MC_dwarf_fill_member_location(type, &member, &child);
-
- xbt_assert(member.type_id, "Missing type for member %s of <%" PRIx64 ">%s", member.name.c_str(),
- (uint64_t)type->id, type->name.c_str());
-
- type->members.push_back(std::move(member));
- }
- }
-}
-
-/** @brief Create a MC type object from a DIE
- *
- * @param info current object info object
- * @param die DIE (for a given type)
- * @param unit compilation unit of the current DIE
- * @return MC representation of the type
- */
-static simgrid::mc::Type MC_dwarf_die_to_type(simgrid::mc::ObjectInformation* info, Dwarf_Die* die, Dwarf_Die* unit,
- simgrid::mc::Frame* frame, const char* ns)
-{
- simgrid::mc::Type type;
- type.type = dwarf_tag(die);
- type.name = std::string();
- type.element_count = -1;
-
- // Global Offset
- type.id = dwarf_dieoffset(die);
-
- const char* prefix = "";
- switch (type.type) {
- case DW_TAG_structure_type:
- prefix = "struct ";
- break;
- case DW_TAG_union_type:
- prefix = "union ";
- break;
- case DW_TAG_class_type:
- prefix = "class ";
- break;
- default:
- prefix = "";
- }
-
- const char* name = MC_dwarf_attr_integrate_string(die, DW_AT_name);
- if (name != nullptr) {
- if (ns)
- type.name = simgrid::xbt::string_printf("%s%s::%s", prefix, ns, name);
- else
- type.name = simgrid::xbt::string_printf("%s%s", prefix, name);
- }
-
- type.type_id = MC_dwarf_at_type(die);
-
- // Some compilers do not emit DW_AT_byte_size for pointer_type,
- // so we fill this. We currently assume that the model-checked process is in
- // the same architecture..
- if (type.type == DW_TAG_pointer_type)
- type.byte_size = sizeof(void*);
-
- // Computation of the byte_size
- if (dwarf_hasattr_integrate(die, DW_AT_byte_size))
- type.byte_size = MC_dwarf_attr_integrate_uint(die, DW_AT_byte_size, 0);
- else if (type.type == DW_TAG_array_type || type.type == DW_TAG_structure_type || type.type == DW_TAG_class_type) {
- Dwarf_Word size;
- if (dwarf_aggregate_size(die, &size) == 0)
- type.byte_size = size;
- }
-
- switch (type.type) {
- case DW_TAG_array_type:
- type.element_count = MC_dwarf_array_element_count(die, unit);
- // TODO, handle DW_byte_stride and (not) DW_bit_stride
- break;
-
- case DW_TAG_pointer_type:
- case DW_TAG_reference_type:
- case DW_TAG_rvalue_reference_type:
- break;
-
- case DW_TAG_structure_type:
- case DW_TAG_union_type:
- case DW_TAG_class_type:
- MC_dwarf_add_members(info, die, unit, &type);
- MC_dwarf_handle_children(info, die, unit, frame,
- ns ? simgrid::xbt::string_printf("%s::%s", ns, name).c_str() : type.name.c_str());
- break;
-
- default:
- XBT_DEBUG("Unhandled type: %d (%s)", type.type, simgrid::dwarf::tagname(type.type));
- break;
- }
-
- return type;
-}
-
-static void MC_dwarf_handle_type_die(simgrid::mc::ObjectInformation* info, Dwarf_Die* die, Dwarf_Die* unit,
- simgrid::mc::Frame* frame, const char* ns)
-{
- simgrid::mc::Type type = MC_dwarf_die_to_type(info, die, unit, frame, ns);
- auto& t = (info->types[type.id] = std::move(type));
- if (not t.name.empty() && type.byte_size != 0)
- info->full_types_by_name[t.name] = &t;
-}
-
-static int mc_anonymous_variable_index = 0;
-
-static std::unique_ptr<simgrid::mc::Variable> MC_die_to_variable(simgrid::mc::ObjectInformation* info, Dwarf_Die* die,
- Dwarf_Die* /*unit*/, simgrid::mc::Frame* frame,
- const char* ns)
-{
- // Skip declarations:
- if (MC_dwarf_attr_flag(die, DW_AT_declaration, false))
- return nullptr;
-
- // Skip compile time constants:
- if (dwarf_hasattr(die, DW_AT_const_value))
- return nullptr;
-
- Dwarf_Attribute attr_location;
- if (dwarf_attr(die, DW_AT_location, &attr_location) == nullptr)
- // No location: do not add it ?
- return nullptr;
-
- std::unique_ptr<simgrid::mc::Variable> variable = std::unique_ptr<simgrid::mc::Variable>(new simgrid::mc::Variable());
- variable->id = dwarf_dieoffset(die);
- variable->global = frame == nullptr; // Can be override base on DW_AT_location
- variable->object_info = info;
-
- const char* name = MC_dwarf_attr_integrate_string(die, DW_AT_name);
- if (name)
- variable->name = name;
- variable->type_id = MC_dwarf_at_type(die);
-
- int form = dwarf_whatform(&attr_location);
- simgrid::dwarf::FormClass form_class;
- if (form == DW_FORM_sec_offset)
- form_class = simgrid::dwarf::FormClass::Constant;
- else
- form_class = simgrid::dwarf::classify_form(form);
- switch (form_class) {
- case simgrid::dwarf::FormClass::ExprLoc:
- case simgrid::dwarf::FormClass::Block:
- // Location expression:
- {
- Dwarf_Op* expr;
- size_t len;
- xbt_assert(not dwarf_getlocation(&attr_location, &expr, &len),
- "Could not read location expression in DW_AT_location "
- "of variable <%" PRIx64 ">%s",
- (uint64_t)variable->id, variable->name.c_str());
-
- if (len == 1 && expr[0].atom == DW_OP_addr) {
- variable->global = true;
- uintptr_t offset = (uintptr_t)expr[0].number;
- uintptr_t base = (uintptr_t)info->base_address();
- variable->address = (void*)(base + offset);
- } else
- variable->location_list = {
- simgrid::dwarf::LocationListEntry(simgrid::dwarf::DwarfExpression(expr, expr + len))};
-
- break;
- }
-
- case simgrid::dwarf::FormClass::LocListPtr:
- case simgrid::dwarf::FormClass::Constant:
- // Reference to location list:
- variable->location_list = simgrid::dwarf::location_list(*info, attr_location);
- break;
-
- default:
- xbt_die("Unexpected form 0x%x (%i), class 0x%x (%i) list for location in <%" PRIx64 ">%s", (unsigned)form, form,
- (unsigned)form_class, (int)form_class, (uint64_t)variable->id, variable->name.c_str());
- }
-
- // Handle start_scope:
- if (dwarf_hasattr(die, DW_AT_start_scope)) {
- Dwarf_Attribute attr;
- dwarf_attr(die, DW_AT_start_scope, &attr);
- form = dwarf_whatform(&attr);
- form_class = simgrid::dwarf::classify_form(form);
- if (form_class == simgrid::dwarf::FormClass::Constant) {
- Dwarf_Word value;
- variable->start_scope = dwarf_formudata(&attr, &value) == 0 ? (size_t)value : 0;
- } else {
- // TODO: FormClass::RangeListPtr
- xbt_die("Unhandled form 0x%x, class 0x%X for DW_AT_start_scope of variable %s", (unsigned)form,
- (unsigned)form_class, name == nullptr ? "?" : name);
- }
- }
-
- if (ns && variable->global)
- variable->name = std::string(ns) + "::" + variable->name;
-
- // The current code needs a variable name,
- // generate a fake one:
- if (variable->name.empty()) {
- variable->name = "@anonymous#" + std::to_string(mc_anonymous_variable_index);
- mc_anonymous_variable_index++;
- }
- return variable;
-}
-
-static void MC_dwarf_handle_variable_die(simgrid::mc::ObjectInformation* info, Dwarf_Die* die, Dwarf_Die* unit,
- simgrid::mc::Frame* frame, const char* ns)
-{
- std::unique_ptr<simgrid::mc::Variable> variable = MC_die_to_variable(info, die, unit, frame, ns);
- if (not variable)
- return;
- // Those arrays are sorted later:
- if (variable->global)
- info->global_variables.push_back(std::move(*variable));
- else if (frame != nullptr)
- frame->variables.push_back(std::move(*variable));
- else
- xbt_die("No frame for this local variable");
-}
-
-static void MC_dwarf_handle_scope_die(simgrid::mc::ObjectInformation* info, Dwarf_Die* die, Dwarf_Die* unit,
- simgrid::mc::Frame* parent_frame, const char* ns)
-{
- // TODO, handle DW_TAG_type/DW_TAG_location for DW_TAG_with_stmt
- int tag = dwarf_tag(die);
- simgrid::dwarf::TagClass klass = simgrid::dwarf::classify_tag(tag);
-
- // (Template) Subprogram declaration:
- if (klass == simgrid::dwarf::TagClass::Subprogram && MC_dwarf_attr_flag(die, DW_AT_declaration, false))
- return;
-
- if (klass == simgrid::dwarf::TagClass::Scope)
- xbt_assert(parent_frame, "No parent scope for this scope");
-
- simgrid::mc::Frame frame;
- frame.tag = tag;
- frame.id = dwarf_dieoffset(die);
- frame.object_info = info;
-
- if (klass == simgrid::dwarf::TagClass::Subprogram) {
- const char* name = MC_dwarf_attr_integrate_string(die, DW_AT_name);
- if (name && ns)
- frame.name = std::string(ns) + "::" + name;
- else if (name)
- frame.name = name;
- }
-
- frame.abstract_origin_id = MC_dwarf_attr_dieoffset(die, DW_AT_abstract_origin);
-
- // This is the base address for DWARF addresses.
- // Relocated addresses are offset from this base address.
- // See DWARF4 spec 7.5
- std::uint64_t base = (std::uint64_t)info->base_address();
-
- // TODO, support DW_AT_ranges
- uint64_t low_pc = MC_dwarf_attr_integrate_addr(die, DW_AT_low_pc);
- frame.range.begin() = low_pc ? (std::uint64_t)base + low_pc : 0;
- if (low_pc) {
- // DW_AT_high_pc:
- Dwarf_Attribute attr;
- xbt_assert(dwarf_attr_integrate(die, DW_AT_high_pc, &attr), "Missing DW_AT_high_pc matching with DW_AT_low_pc");
-
- Dwarf_Sword offset;
- Dwarf_Addr high_pc;
-
- switch (simgrid::dwarf::classify_form(dwarf_whatform(&attr))) {
-
- // DW_AT_high_pc if an offset from the low_pc:
- case simgrid::dwarf::FormClass::Constant:
-
- xbt_assert(dwarf_formsdata(&attr, &offset) == 0, "Could not read constant");
- frame.range.end() = frame.range.begin() + offset;
- break;
-
- // DW_AT_high_pc is a relocatable address:
- case simgrid::dwarf::FormClass::Address:
- xbt_assert(dwarf_formaddr(&attr, &high_pc) == 0, "Could not read address");
- frame.range.end() = base + high_pc;
- break;
-
- default:
- xbt_die("Unexpected class for DW_AT_high_pc");
- }
- }
-
- if (klass == simgrid::dwarf::TagClass::Subprogram) {
- Dwarf_Attribute attr_frame_base;
- if (dwarf_attr_integrate(die, DW_AT_frame_base, &attr_frame_base))
- frame.frame_base_location = simgrid::dwarf::location_list(*info, attr_frame_base);
- }
-
- // Handle children:
- MC_dwarf_handle_children(info, die, unit, &frame, ns);
-
- // We sort them in order to have an (somewhat) efficient by name
- // lookup:
- boost::range::sort(frame.variables, MC_compare_variable);
-
- // Register it:
- if (klass == simgrid::dwarf::TagClass::Subprogram)
- info->subprograms[frame.id] = std::move(frame);
- else if (klass == simgrid::dwarf::TagClass::Scope)
- parent_frame->scopes.push_back(std::move(frame));
-}
-
-static void mc_dwarf_handle_namespace_die(simgrid::mc::ObjectInformation* info, Dwarf_Die* die, Dwarf_Die* unit,
- simgrid::mc::Frame* frame, const char* ns)
-{
- const char* name = MC_dwarf_attr_integrate_string(die, DW_AT_name);
- xbt_assert(not frame, "Unexpected namespace in a subprogram");
- char* new_ns = ns == nullptr ? xbt_strdup(name) : bprintf("%s::%s", ns, name);
- MC_dwarf_handle_children(info, die, unit, frame, new_ns);
- xbt_free(new_ns);
-}
-
-static void MC_dwarf_handle_children(simgrid::mc::ObjectInformation* info, Dwarf_Die* die, Dwarf_Die* unit,
- simgrid::mc::Frame* frame, const char* ns)
-{
- // For each child DIE:
- Dwarf_Die child;
- int res;
- for (res = dwarf_child(die, &child); res == 0; res = dwarf_siblingof(&child, &child))
- MC_dwarf_handle_die(info, &child, unit, frame, ns);
-}
-
-static void MC_dwarf_handle_die(simgrid::mc::ObjectInformation* info, Dwarf_Die* die, Dwarf_Die* unit,
- simgrid::mc::Frame* frame, const char* ns)
-{
- int tag = dwarf_tag(die);
- simgrid::dwarf::TagClass klass = simgrid::dwarf::classify_tag(tag);
- switch (klass) {
-
- // Type:
- case simgrid::dwarf::TagClass::Type:
- MC_dwarf_handle_type_die(info, die, unit, frame, ns);
- break;
-
- // Subprogram or scope:
- case simgrid::dwarf::TagClass::Subprogram:
- case simgrid::dwarf::TagClass::Scope:
- MC_dwarf_handle_scope_die(info, die, unit, frame, ns);
- return;
-
- // Variable:
- case simgrid::dwarf::TagClass::Variable:
- MC_dwarf_handle_variable_die(info, die, unit, frame, ns);
- break;
-
- case simgrid::dwarf::TagClass::Namespace:
- mc_dwarf_handle_namespace_die(info, die, unit, frame, ns);
- break;
-
- default:
- break;
- }
-}
-
-static Elf64_Half get_type(Elf* elf)
-{
- Elf64_Ehdr* ehdr64 = elf64_getehdr(elf);
- if (ehdr64)
- return ehdr64->e_type;
- Elf32_Ehdr* ehdr32 = elf32_getehdr(elf);
- if (ehdr32)
- return ehdr32->e_type;
- xbt_die("Could not get ELF heeader");
-}
-
-static void read_dwarf_info(simgrid::mc::ObjectInformation* info, Dwarf* dwarf)
-{
- // For each compilation unit:
- Dwarf_Off offset = 0;
- Dwarf_Off next_offset = 0;
- size_t length;
-
- 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, nullptr);
- offset = next_offset;
- }
-}
-
-/** Get the build-id (NT_GNU_BUILD_ID) from the ELF file
- *
- * This build-id may is used to locate an external debug (DWARF) file
- * for this ELF file.
- *
- * @param elf libelf handle for an ELF file
- * @return build-id for this ELF file (or an empty vector if none is found)
- */
-static std::vector<char> get_build_id(Elf* elf)
-{
-#ifdef __linux
- // 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;
- xbt_assert(elf_getphdrnum(elf, &phnum) == 0, "Could not read program headers");
-
- // Iterate over the program headers and find the PT_NOTE ones:
- for (size_t i = 0; i < phnum; ++i) {
- GElf_Phdr phdr_temp;
- GElf_Phdr* phdr = gelf_getphdr(elf, i, &phdr_temp);
- if (phdr->p_type != PT_NOTE)
- continue;
-
- Elf_Data* data = elf_getdata_rawchunk(elf, phdr->p_offset, phdr->p_filesz, ELF_T_NHDR);
-
- // Iterate over the notes and find the NT_GNU_BUILD_ID one:
- size_t pos = 0;
- 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 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) {
- 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);
- }
- }
- }
-#endif
- return std::vector<char>();
-}
-
-static char hexdigits[16] = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};
-
-/** Binary data to hexadecimal */
-static inline std::array<char, 2> to_hex(std::uint8_t byte)
-{
- // Horrid double braces!
- // Apparently, this is needed in C++11 (not in C++14).
- return {{hexdigits[byte >> 4], hexdigits[byte & 0xF]}};
-}
-
-/** Binary data to hexadecimal */
-static std::string to_hex(const char* data, std::size_t count)
-{
- std::string res;
- res.resize(2 * count);
- for (std::size_t i = 0; i < count; i++) {
- std::array<char, 2> hex_byte = to_hex(data[i]);
- for (int j = 0; j < 2; ++j)
- res[2 * i + j] = hex_byte[j];
- }
- return res;
-}
-
-/** Binary data to hexadecimal */
-static std::string to_hex(std::vector<char> const& data)
-{
- return to_hex(data.data(), data.size());
-}
-
-/** Base directories for external debug files */
-static const char* debug_paths[] = {
- "/usr/lib/debug/",
- "/usr/local/lib/debug/",
-};
-
-/** Locate an external debug file from the NT_GNU_BUILD_ID
- *
- * 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* const& debug_path : debug_paths) {
- // 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) {
- 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();
-}
-
-/** @brief Populate the debugging informations of the given ELF object
- *
- * Read the DWARf information of the EFFL object and populate the
- * lists of types, variables, functions.
- */
-static void MC_load_dwarf(simgrid::mc::ObjectInformation* info)
-{
- xbt_assert(elf_version(EV_CURRENT) != EV_NONE, "libelf initialization error");
-
- // Open the ELF file:
- int fd = open(info->file_name.c_str(), O_RDONLY);
- xbt_assert(fd >= 0, "Could not open file %s", info->file_name.c_str());
- Elf* elf = elf_begin(fd, ELF_C_READ, nullptr);
- xbt_assert(elf != nullptr, "Not an ELF file");
- Elf_Kind kind = elf_kind(elf);
- xbt_assert(kind == ELF_K_ELF, "Not an ELF file");
-
- // 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;
-
- // Read DWARF debug information in the file:
- Dwarf* dwarf = dwarf_begin_elf(elf, DWARF_C_READ, nullptr);
- if (dwarf != nullptr) {
- read_dwarf_info(info, dwarf);
- dwarf_end(dwarf);
- elf_end(elf);
- close(fd);
- return;
- }
- dwarf_end(dwarf);
-
- // 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 (not build_id.empty()) {
- elf_end(elf);
- close(fd);
-
- // Find the debug file using the build id:
- std::string debug_file = find_by_build_id(build_id);
- xbt_assert(not debug_file.empty(),
- "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(), to_hex(build_id).c_str());
-
- // Load the DWARF info from this file:
- XBT_DEBUG("Load DWARF for %s from %s", info->file_name.c_str(), debug_file.c_str());
- fd = open(debug_file.c_str(), O_RDONLY);
- xbt_assert(fd >= 0, "Could not open file %s", debug_file.c_str());
- dwarf = dwarf_begin(fd, DWARF_C_READ);
- xbt_assert(dwarf != nullptr, "No DWARF info in %s for %s", debug_file.c_str(), info->file_name.c_str());
- read_dwarf_info(info, dwarf);
- dwarf_end(dwarf);
- close(fd);
- return;
- }
-
- // 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());
-}
-
-// ***** Functions index
-
-static void MC_make_functions_index(simgrid::mc::ObjectInformation* info)
-{
- info->functions_index.clear();
-
- for (auto& e : info->subprograms) {
- if (e.second.range.begin() == 0)
- continue;
- simgrid::mc::FunctionIndexEntry entry;
- entry.low_pc = (void*)e.second.range.begin();
- entry.function = &e.second;
- info->functions_index.push_back(entry);
- }
-
- info->functions_index.shrink_to_fit();
-
- // Sort the array by low_pc:
- boost::range::sort(info->functions_index,
- [](simgrid::mc::FunctionIndexEntry const& a, simgrid::mc::FunctionIndexEntry const& b) {
- return a.low_pc < b.low_pc;
- });
-}
-
-static void MC_post_process_variables(simgrid::mc::ObjectInformation* info)
-{
- // Someone needs this to be sorted but who?
- boost::range::sort(info->global_variables, MC_compare_variable);
-
- for (simgrid::mc::Variable& variable : info->global_variables)
- if (variable.type_id)
- variable.type = simgrid::util::find_map_ptr(info->types, variable.type_id);
-}
-
-static void mc_post_process_scope(simgrid::mc::ObjectInformation* info, simgrid::mc::Frame* scope)
-{
-
- if (scope->tag == DW_TAG_inlined_subroutine) {
- // Attach correct namespaced name in inlined subroutine:
- auto i = info->subprograms.find(scope->abstract_origin_id);
- xbt_assert(i != info->subprograms.end(), "Could not lookup abstract origin %" PRIx64,
- (std::uint64_t)scope->abstract_origin_id);
- scope->name = i->second.name;
- }
-
- // Direct:
- for (simgrid::mc::Variable& variable : scope->variables)
- if (variable.type_id)
- variable.type = simgrid::util::find_map_ptr(info->types, variable.type_id);
-
- // Recursive post-processing of nested-scopes:
- for (simgrid::mc::Frame& nested_scope : scope->scopes)
- mc_post_process_scope(info, &nested_scope);
-}
-
-static simgrid::mc::Type* MC_resolve_type(simgrid::mc::ObjectInformation* info, unsigned type_id)
-{
- if (not type_id)
- return nullptr;
- simgrid::mc::Type* type = simgrid::util::find_map_ptr(info->types, type_id);
- if (type == nullptr)
- return nullptr;
-
- // We already have the information on the type:
- if (type->byte_size != 0)
- return type;
-
- // Don't have a name, we can't find a more complete version:
- if (type->name.empty())
- return type;
-
- // Try to find a more complete description of the type:
- // We need to fix in order to support C++.
- simgrid::mc::Type** subtype = simgrid::util::find_map_ptr(info->full_types_by_name, type->name);
- if (subtype)
- type = *subtype;
- return type;
-}
-
-static void MC_post_process_types(simgrid::mc::ObjectInformation* info)
-{
- // Lookup "subtype" field:
- for (auto& i : info->types) {
- i.second.subtype = MC_resolve_type(info, i.second.type_id);
- for (simgrid::mc::Member& member : i.second.members)
- member.type = MC_resolve_type(info, member.type_id);
- }
-}
-
-namespace simgrid {
-namespace mc {
-
-/** @brief Finds informations about a given shared object/executable */
-std::shared_ptr<simgrid::mc::ObjectInformation> createObjectInformation(std::vector<simgrid::xbt::VmMap> const& maps,
- const char* name)
-{
- std::shared_ptr<simgrid::mc::ObjectInformation> result = std::make_shared<simgrid::mc::ObjectInformation>();
- result->file_name = name;
- simgrid::mc::find_object_address(maps, 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 result;
-}
-
-/*************************************************************************/
-
-void postProcessObjectInformation(simgrid::mc::RemoteClient* process, simgrid::mc::ObjectInformation* info)
-{
- for (auto& t : info->types) {
-
- simgrid::mc::Type* type = &(t.second);
- simgrid::mc::Type* subtype = type;
- while (subtype->type == DW_TAG_typedef || subtype->type == DW_TAG_volatile_type ||
- subtype->type == DW_TAG_const_type)
- if (subtype->subtype)
- subtype = subtype->subtype;
- else
- break;
-
- // Resolve full_type:
- if (not subtype->name.empty() && subtype->byte_size == 0)
- for (auto const& object_info : process->object_infos) {
- auto i = object_info->full_types_by_name.find(subtype->name);
- if (i != object_info->full_types_by_name.end() && not i->second->name.empty() && i->second->byte_size) {
- type->full_type = i->second;
- break;
- }
- }
- else
- type->full_type = subtype;
- }
-}
-
-} // namespace mc
-} // namespace simgrid
-
-namespace simgrid {
-namespace dwarf {
-
-/** Convert a DWARF register into a libunwind register
- *
- * DWARF and libunwind does not use the same convention for numbering the
- * registers on some architectures. The function makes the necessary
- * conversion.
- */
-int dwarf_register_to_libunwind(int dwarf_register)
-{
-#if defined(__x86_64__)
- // It seems for this arch, DWARF and libunwind agree in the numbering:
- return dwarf_register;
-#elif defined(__i386__)
- // 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:
- return UNW_X86_EAX;
- case 1:
- return UNW_X86_ECX;
- case 2:
- return UNW_X86_EDX;
- case 3:
- return UNW_X86_EBX;
- case 4:
- return UNW_X86_ESP;
- case 5:
- return UNW_X86_EBP;
- case 6:
- return UNW_X86_ESI;
- case 7:
- return UNW_X86_EDI;
- case 8:
- return UNW_X86_EIP;
- case 9:
- return UNW_X86_EFLAGS;
- case 10:
- return UNW_X86_CS;
- case 11:
- return UNW_X86_SS;
- case 12:
- return UNW_X86_DS;
- case 13:
- return UNW_X86_ES;
- case 14:
- return UNW_X86_FS;
- case 15:
- return UNW_X86_GS;
- case 16:
- return UNW_X86_ST0;
- case 17:
- return UNW_X86_ST1;
- case 18:
- return UNW_X86_ST2;
- case 19:
- return UNW_X86_ST3;
- case 20:
- return UNW_X86_ST4;
- case 21:
- return UNW_X86_ST5;
- case 22:
- return UNW_X86_ST6;
- case 23:
- return UNW_X86_ST7;
- default:
- xbt_die("Bad/unknown register number.");
- }
-#else
-#error This architecture is not supported yet for DWARF expression evaluation.
-#endif
-}
-
-} // namespace dwarf
-} // namespace simgrid
