X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/b0b472673e070422be16c2355105ddabee16243e..872d65264714799b25eb231609c3f05bae3d03dc:/src/mc/mc_dwarf.cpp diff --git a/src/mc/mc_dwarf.cpp b/src/mc/mc_dwarf.cpp index 7bdc76ef88..30b5f38400 100644 --- a/src/mc/mc_dwarf.cpp +++ b/src/mc/mc_dwarf.cpp @@ -1,30 +1,35 @@ -/* Copyright (c) 2008-2014. The SimGrid Team. +/* Copyright (c) 2008-2015. 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 +#include -#include +#include +#include +#include + +#include +#include #define DW_LANG_Objc DW_LANG_ObjC /* fix spelling error in older dwarf.h */ #include #include +#include + #include +#include "src/simgrid/util.hpp" #include #include -#include "mc_object_info.h" -#include "mc_private.h" +#include "src/mc/mc_private.h" +#include "src/mc/mc_dwarf.hpp" -static void dw_variable_free(dw_variable_t v); -static void dw_variable_free_voidp(void *t); - -static void MC_dwarf_register_global_variable(mc_object_info_t info, dw_variable_t variable); -static void MC_register_variable(mc_object_info_t info, dw_frame_t frame, dw_variable_t variable); -static void MC_dwarf_register_non_global_variable(mc_object_info_t info, dw_frame_t frame, dw_variable_t variable); -static void MC_dwarf_register_variable(mc_object_info_t info, dw_frame_t frame, dw_variable_t variable); +#include "src/mc/Process.hpp" +#include "src/mc/ObjectInformation.hpp" +#include "src/mc/Variable.hpp" XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_dwarf, mc, "DWARF processing"); @@ -63,14 +68,14 @@ static uint64_t MC_dwarf_array_element_count(Dwarf_Die * die, Dwarf_Die * unit); * \param unit the DIE of the compile unit of the current DIE * \param frame containg frame if any */ -static void MC_dwarf_handle_die(mc_object_info_t info, Dwarf_Die * die, - Dwarf_Die * unit, dw_frame_t frame, +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(mc_object_info_t info, Dwarf_Die * die, - Dwarf_Die * unit, dw_frame_t frame, +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 childrend of the given die @@ -80,8 +85,8 @@ static void MC_dwarf_handle_type_die(mc_object_info_t info, Dwarf_Die * die, * \param unit the DIE of the compile unit of the current DIE * \param frame containg frame if any */ -static void MC_dwarf_handle_children(mc_object_info_t info, Dwarf_Die * die, - Dwarf_Die * unit, dw_frame_t frame, +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) @@ -91,29 +96,47 @@ static void MC_dwarf_handle_children(mc_object_info_t info, Dwarf_Die * die, * \param unit the DIE of the compile unit of the current DIE * \param frame containg frame if any */ -static void MC_dwarf_handle_variable_die(mc_object_info_t info, Dwarf_Die * die, - Dwarf_Die * unit, dw_frame_t frame, +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 (NULL if none) + * \return DW_TAG_type attribute as a new string (nullptr if none) */ -static char *MC_dwarf_at_type(Dwarf_Die * die); +static std::uint64_t MC_dwarf_at_type(Dwarf_Die * die); -/** \brief A class of DWARF tags (DW_TAG_*) - */ -typedef enum mc_tag_class { - mc_tag_unknown, - mc_tag_type, - mc_tag_subprogram, - mc_tag_variable, - mc_tag_scope, - mc_tag_namespace -} mc_tag_class; - -static mc_tag_class MC_dwarf_tag_classify(int tag) +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) { @@ -140,44 +163,30 @@ static mc_tag_class MC_dwarf_tag_classify(int tag) case DW_TAG_interface_type: case DW_TAG_unspecified_type: case DW_TAG_shared_type: - return mc_tag_type; + return TagClass::Type; case DW_TAG_subprogram: - return mc_tag_subprogram; + return TagClass::Subprogram; case DW_TAG_variable: case DW_TAG_formal_parameter: - return mc_tag_variable; + 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 mc_tag_scope; + return TagClass::Scope; case DW_TAG_namespace: - return mc_tag_namespace; + return TagClass::Namespace; default: - return mc_tag_unknown; - + return TagClass::Unknown; } } -#define MC_DW_CLASS_UNKNOWN 0 -#define MC_DW_CLASS_ADDRESS 1 // Location in the address space of the program -#define MC_DW_CLASS_BLOCK 2 // Arbitrary block of bytes -#define MC_DW_CLASS_CONSTANT 3 -#define MC_DW_CLASS_STRING 3 // String -#define MC_DW_CLASS_FLAG 4 // Boolean -#define MC_DW_CLASS_REFERENCE 5 // Reference to another DIE -#define MC_DW_CLASS_EXPRLOC 6 // DWARF expression/location description -#define MC_DW_CLASS_LINEPTR 7 -#define MC_DW_CLASS_LOCLISTPTR 8 -#define MC_DW_CLASS_MACPTR 9 -#define MC_DW_CLASS_RANGELISTPTR 10 - /** \brief Find the DWARF data class for a given DWARF data form * * This mapping is defined in the DWARF spec. @@ -185,42 +194,43 @@ static mc_tag_class MC_dwarf_tag_classify(int tag) * \param form The form (values taken from the DWARF spec) * \return An internal representation for the corresponding class * */ -static int MC_dwarf_form_get_class(int form) +static +FormClass classify_form(int form) { switch (form) { case DW_FORM_addr: - return MC_DW_CLASS_ADDRESS; + return FormClass::Address; case DW_FORM_block2: case DW_FORM_block4: case DW_FORM_block: case DW_FORM_block1: - return MC_DW_CLASS_BLOCK; + 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 MC_DW_CLASS_CONSTANT; + return FormClass::Constant; case DW_FORM_string: case DW_FORM_strp: - return MC_DW_CLASS_STRING; + 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 MC_DW_CLASS_REFERENCE; + return FormClass::Reference; case DW_FORM_flag: case DW_FORM_flag_present: - return MC_DW_CLASS_FLAG; + return FormClass::Flag; case DW_FORM_exprloc: - return MC_DW_CLASS_EXPRLOC; + return FormClass::ExprLoc; // TODO sec offset // TODO indirect default: - return MC_DW_CLASS_UNKNOWN; + return FormClass::Unknown; } } @@ -229,9 +239,13 @@ static int MC_dwarf_form_get_class(int form) * \param die DIE * \return name of the tag of this DIE */ -static inline const char *MC_dwarf_die_tagname(Dwarf_Die * die) +inline XBT_PRIVATE +const char *tagname(Dwarf_Die * die) { - return MC_dwarf_tagname(dwarf_tag(die)); + return simgrid::dwarf::tagname(dwarf_tag(die)); +} + +} } // ***** Attributes @@ -246,11 +260,10 @@ static const char *MC_dwarf_attr_integrate_string(Dwarf_Die * die, int attribute) { Dwarf_Attribute attr; - if (!dwarf_attr_integrate(die, attribute, &attr)) { - return NULL; - } else { + if (!dwarf_attr_integrate(die, attribute, &attr)) + return nullptr; + else return dwarf_formstring(&attr); - } } /** \brief Get the linkage name of a DIE. @@ -261,7 +274,7 @@ static const char *MC_dwarf_attr_integrate_string(Dwarf_Die * die, * DW_AT_MIPS_linkage_name is used (at least by GCC). * * \param the DIE - * \return linkage name of the given DIE (or NULL) + * \return linkage name of the given DIE (or nullptr) * */ static const char *MC_dwarf_at_linkage_name(Dwarf_Die * die) { @@ -274,47 +287,43 @@ static const char *MC_dwarf_at_linkage_name(Dwarf_Die * die) static Dwarf_Off MC_dwarf_attr_dieoffset(Dwarf_Die * die, int attribute) { Dwarf_Attribute attr; - if (dwarf_hasattr_integrate(die, attribute)) { - dwarf_attr_integrate(die, attribute, &attr); - Dwarf_Die subtype_die; - if (dwarf_formref_die(&attr, &subtype_die) == NULL) { - xbt_die("Could not find DIE"); - } - return dwarf_dieoffset(&subtype_die); - } else + if (dwarf_hasattr_integrate(die, attribute) == 0) return 0; + dwarf_attr_integrate(die, attribute, &attr); + Dwarf_Die subtype_die; + if (dwarf_formref_die(&attr, &subtype_die) == nullptr) + xbt_die("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)) { - dwarf_attr_integrate(die, DW_AT_type, &attr); - Dwarf_Die subtype_die; - if (dwarf_formref_die(&attr, &subtype_die) == NULL) { - xbt_die("Could not find DIE"); - } - return dwarf_dieoffset(&subtype_die); - } else + if (dwarf_hasattr_integrate(die, attribute) == 0) return 0; + dwarf_attr_integrate(die, DW_AT_type, &attr); + Dwarf_Die subtype_die; + if (dwarf_formref_die(&attr, &subtype_die) == nullptr) + xbt_die("Could not find DIE"); + return dwarf_dieoffset(&subtype_die); } /** \brief Find the type/subtype (DW_AT_type) for a DIE * * \param dit the DIE - * \return DW_AT_type reference as a global offset in hexadecimal (or NULL) + * \return DW_AT_type reference as a global offset in hexadecimal (or nullptr) */ -static char *MC_dwarf_at_type(Dwarf_Die * die) +static +std::uint64_t MC_dwarf_at_type(Dwarf_Die * die) { - Dwarf_Off offset = MC_dwarf_attr_integrate_dieoffset(die, DW_AT_type); - return offset == 0 ? NULL : bprintf("%" PRIx64, offset); + 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) == NULL) + if (dwarf_attr_integrate(die, attribute, &attr) == nullptr) return 0; Dwarf_Addr value; if (dwarf_formaddr(&attr, &value) == 0) @@ -327,7 +336,7 @@ 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) == NULL) + if (dwarf_attr_integrate(die, attribute, &attr) == nullptr) return default_value; Dwarf_Word value; return dwarf_formudata(dwarf_attr_integrate(die, attribute, &attr), @@ -343,7 +352,8 @@ static bool MC_dwarf_attr_flag(Dwarf_Die * die, int attribute, bool integrate) bool result; if (dwarf_formflag(&attr, &result)) - xbt_die("Unexpected form for attribute %s", MC_dwarf_attrname(attribute)); + xbt_die("Unexpected form for attribute %s", + simgrid::dwarf::attrname(attribute)); return result; } @@ -399,27 +409,25 @@ static uint64_t MC_dwarf_subrange_element_count(Dwarf_Die * die, 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", - MC_dwarf_die_tagname(die)); + simgrid::dwarf::tagname(die)); // Use DW_TAG_count if present: - if (dwarf_hasattr_integrate(die, DW_AT_count)) { + 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 (!dwarf_hasattr_integrate(die, DW_AT_upper_bound)) { + if (!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, -1); uint64_t lower_bound = 0; - if (dwarf_hasattr_integrate(die, DW_AT_lower_bound)) { + if (dwarf_hasattr_integrate(die, DW_AT_lower_bound)) lower_bound = MC_dwarf_attr_integrate_uint(die, DW_AT_lower_bound, -1); - } else { + else lower_bound = MC_dwarf_default_lower_bound(dwarf_srclang(unit)); - } return upper_bound - lower_bound + 1; } @@ -436,7 +444,7 @@ 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", - MC_dwarf_die_tagname(die)); + simgrid::dwarf::tagname(die)); int result = 1; Dwarf_Die child; @@ -445,14 +453,31 @@ static uint64_t MC_dwarf_array_element_count(Dwarf_Die * die, Dwarf_Die * unit) res = dwarf_siblingof(&child, &child)) { int child_tag = dwarf_tag(&child); if (child_tag == DW_TAG_subrange_type - || child_tag == DW_TAG_enumeration_type) { + || child_tag == DW_TAG_enumeration_type) result *= MC_dwarf_subrange_element_count(&child, unit); - } } return result; } -// ***** mc_type_t +// ***** 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 = strcmp(a.name.c_str(), b.name.c_str()); + 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). @@ -461,78 +486,65 @@ static uint64_t MC_dwarf_array_element_count(Dwarf_Die * die, Dwarf_Die * unit) * \param member the member of the type * \param child DIE of the member (DW_TAG_member) */ -static void MC_dwarf_fill_member_location(mc_type_t type, mc_type_t member, - Dwarf_Die * child) +static void MC_dwarf_fill_member_location( + simgrid::mc::Type* type, simgrid::mc::Member* member, Dwarf_Die * child) { - if (dwarf_hasattr(child, DW_AT_data_bit_offset)) { + if (dwarf_hasattr(child, DW_AT_data_bit_offset)) xbt_die("Can't groke DW_AT_data_bit_offset."); - } if (!dwarf_hasattr_integrate(child, DW_AT_data_member_location)) { - if (type->type != DW_TAG_union_type) { - 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()); - } else { + 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); - int klass = MC_dwarf_form_get_class(form); - switch (klass) { - case MC_DW_CLASS_EXPRLOC: - case MC_DW_CLASS_BLOCK: + 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; - if (dwarf_getlocation(&attr, &expr, &len)) { + if (dwarf_getlocation(&attr, &expr, &len)) xbt_die ("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()); - } - if (len == 1 && expr[0].atom == DW_OP_plus_uconst) { - member->offset = expr[0].number; - } else { - mc_dwarf_expression_init(&member->location, len, expr); - } + member->location_expression = simgrid::dwarf::DwarfExpression(expr, expr+len); break; } - case MC_DW_CLASS_CONSTANT: + case simgrid::dwarf::FormClass::Constant: // Offset from the base address of the object: { Dwarf_Word offset; if (!dwarf_formudata(&attr, &offset)) - member->offset = offset; + member->offset(offset); else xbt_die("Cannot get %s location <%" PRIx64 ">%s", MC_dwarf_attr_integrate_string(child, DW_AT_name), (uint64_t) type->id, type->name.c_str()); break; } - case MC_DW_CLASS_LOCLISTPTR: + case simgrid::dwarf::FormClass::LocListPtr: // Reference to a location list: // TODO - case MC_DW_CLASS_REFERENCE: + case simgrid::dwarf::FormClass::Reference: // It's supposed to be possible in DWARF2 but I couldn't find its semantic // in the spec. default: xbt_die("Can't handle form class (%i) / form 0x%x as DW_AT_member_location", - klass, form); + (int) form_class, form); } } -static void dw_type_free_voidp(void *t) -{ - delete *(mc_type_t*)t; -} - /** \brief Populate the list of members of a type * * \param info ELF object containing the type DIE @@ -540,14 +552,12 @@ static void dw_type_free_voidp(void *t) * \param unit DIE of the compilation unit containing the type DIE * \param type the type */ -static void MC_dwarf_add_members(mc_object_info_t info, Dwarf_Die * die, - Dwarf_Die * unit, mc_type_t 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); - type->members = - xbt_dynar_new(sizeof(mc_type_t), (void (*)(void *)) dw_type_free_voidp); + xbt_assert(type->members.empty()); for (res = dwarf_child(die, &child); res == 0; res = dwarf_siblingof(&child, &child)) { int tag = dwarf_tag(&child); @@ -562,38 +572,51 @@ static void MC_dwarf_add_members(mc_object_info_t info, Dwarf_Die * die, continue; // TODO, we should use another type (because is is not a type but a member) - mc_type_t member = new simgrid::mc::Type(); - member->type = tag; - - // Global Offset: - member->id = dwarf_dieoffset(&child); + 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; - member->byte_size = + 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 stolution 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->element_count = -1; + member.type_id = MC_dwarf_at_type(&child); - char* type_id = MC_dwarf_at_type(&child); - if (type_id) { - member->dw_type_id = type_id; - free(type_id); - } - - if (dwarf_hasattr(&child, DW_AT_data_bit_offset)) { + if (dwarf_hasattr(&child, DW_AT_data_bit_offset)) xbt_die("Can't groke DW_AT_data_bit_offset."); - } - MC_dwarf_fill_member_location(type, member, &child); + MC_dwarf_fill_member_location(type, &member, &child); - if (member->dw_type_id.empty()) { + if (!member.type_id) xbt_die("Missing type for member %s of <%" PRIx64 ">%s", - member->name.c_str(), + member.name.c_str(), (uint64_t) type->id, type->name.c_str()); - } - xbt_dynar_push(type->members, &member); + type->members.push_back(std::move(member)); } } } @@ -605,23 +628,21 @@ static void MC_dwarf_add_members(mc_object_info_t info, Dwarf_Die * die, * \param unit compilation unit of the current DIE * \return MC representation of the type */ -static mc_type_t MC_dwarf_die_to_type(mc_object_info_t info, Dwarf_Die * die, - Dwarf_Die * unit, dw_frame_t frame, - const char *ns) +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) { - - mc_type_t type = new simgrid::mc::Type(); - type->type = -1; - type->name = std::string(); - type->element_count = -1; - - type->type = dwarf_tag(die); + simgrid::mc::Type type; + type.type = dwarf_tag(die); + type.name = std::string(); + type.element_count = -1; // Global Offset - type->id = dwarf_dieoffset(die); + type.id = dwarf_dieoffset(die); const char *prefix = ""; - switch (type->type) { + switch (type.type) { case DW_TAG_structure_type: prefix = "struct "; break; @@ -636,54 +657,48 @@ static mc_type_t MC_dwarf_die_to_type(mc_object_info_t info, Dwarf_Die * die, } const char *name = MC_dwarf_attr_integrate_string(die, DW_AT_name); - if (name != NULL) { + if (name != nullptr) { char* full_name = ns ? bprintf("%s%s::%s", prefix, ns, name) : bprintf("%s%s", prefix, name); - type->name = std::string(full_name); + type.name = std::string(full_name); free(full_name); } - char* type_id = MC_dwarf_at_type(die); - if (type_id) { - type->dw_type_id = type_id; - free(type_id); - } + 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*); + 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) { + 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; - } + if (dwarf_aggregate_size(die, &size) == 0) + type.byte_size = size; } - switch (type->type) { + switch (type.type) { case DW_TAG_array_type: - type->element_count = MC_dwarf_array_element_count(die, unit); + 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: - type->is_pointer_type = 1; break; case DW_TAG_structure_type: case DW_TAG_union_type: case DW_TAG_class_type: - MC_dwarf_add_members(info, die, unit, type); - char *new_ns = ns == NULL ? xbt_strdup(type->name.c_str()) + MC_dwarf_add_members(info, die, unit, &type); + char *new_ns = ns == nullptr ? xbt_strdup(type.name.c_str()) : bprintf("%s::%s", ns, name); MC_dwarf_handle_children(info, die, unit, frame, new_ns); free(new_ns); @@ -693,90 +708,93 @@ static mc_type_t MC_dwarf_die_to_type(mc_object_info_t info, Dwarf_Die * die, return type; } -static void MC_dwarf_handle_type_die(mc_object_info_t info, Dwarf_Die * die, - Dwarf_Die * unit, dw_frame_t frame, +static void MC_dwarf_handle_type_die(simgrid::mc::ObjectInformation* info, Dwarf_Die * die, + Dwarf_Die * unit, simgrid::mc::Frame* frame, const char *ns) { - mc_type_t type = MC_dwarf_die_to_type(info, die, unit, frame, ns); - - char *key = bprintf("%" PRIx64, (uint64_t) type->id); - xbt_dict_set(info->types, key, type, NULL); - xbt_free(key); - - if (!type->name.empty() && type->byte_size != 0) { - xbt_dict_set(info->full_types_by_name, type->name.c_str(), type, NULL); - } + simgrid::mc::Type type = MC_dwarf_die_to_type(info, die, unit, frame, ns); + auto& t = (info->types[type.id] = std::move(type)); + if (!t.name.empty() && type.byte_size != 0) + info->full_types_by_name[t.name] = &t; } static int mc_anonymous_variable_index = 0; -static dw_variable_t MC_die_to_variable(mc_object_info_t info, Dwarf_Die * die, - Dwarf_Die * unit, dw_frame_t frame, - const char *ns) +static std::unique_ptr 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 NULL; + return nullptr; // Skip compile time constants: if (dwarf_hasattr(die, DW_AT_const_value)) - return NULL; + return nullptr; Dwarf_Attribute attr_location; - if (dwarf_attr(die, DW_AT_location, &attr_location) == NULL) { + if (dwarf_attr(die, DW_AT_location, &attr_location) == nullptr) // No location: do not add it ? - return NULL; - } + return nullptr; - dw_variable_t variable = xbt_new0(s_dw_variable_t, 1); - variable->dwarf_offset = dwarf_dieoffset(die); - variable->global = frame == NULL; // Can be override base on DW_AT_location + std::unique_ptr variable = + std::unique_ptr(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); - variable->name = xbt_strdup(name); - - variable->type_origin = MC_dwarf_at_type(die); + if (name) + variable->name = name; + variable->type_id = MC_dwarf_at_type(die); int form = dwarf_whatform(&attr_location); - int klass = - form == - DW_FORM_sec_offset ? MC_DW_CLASS_CONSTANT : MC_dwarf_form_get_class(form); - switch (klass) { - case MC_DW_CLASS_EXPRLOC: - case MC_DW_CLASS_BLOCK: + 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; if (dwarf_getlocation(&attr_location, &expr, &len)) { - xbt_die - ("Could not read location expression in DW_AT_location of variable <%" - PRIx64 ">%s", (uint64_t) variable->dwarf_offset, variable->name); + xbt_die( + "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 = 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); - } else { - mc_dwarf_location_list_init_from_expression(&variable->locations, len, - expr); - } + } else + variable->location_list = { + simgrid::dwarf::DwarfExpression(expr, expr + len) }; break; } - case MC_DW_CLASS_LOCLISTPTR: - case MC_DW_CLASS_CONSTANT: + + case simgrid::dwarf::FormClass::LocListPtr: + case simgrid::dwarf::FormClass::Constant: // Reference to location list: - mc_dwarf_location_list_init(&variable->locations, info, die, - &attr_location); + 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", form, form, klass, klass, - (uint64_t) variable->dwarf_offset, variable->name); + 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->id, + variable->name.c_str()); } // Handle start_scope: @@ -784,122 +802,118 @@ static dw_variable_t MC_die_to_variable(mc_object_info_t info, Dwarf_Die * die, Dwarf_Attribute attr; dwarf_attr(die, DW_AT_start_scope, &attr); int form = dwarf_whatform(&attr); - int klass = MC_dwarf_form_get_class(form); - switch (klass) { - case MC_DW_CLASS_CONSTANT: + simgrid::dwarf::FormClass form_class = simgrid::dwarf::classify_form(form); + switch (form_class) { + case simgrid::dwarf::FormClass::Constant: { Dwarf_Word value; variable->start_scope = dwarf_formudata(&attr, &value) == 0 ? (size_t) value : 0; break; } - case MC_DW_CLASS_RANGELISTPTR: // TODO + + case simgrid::dwarf::FormClass::RangeListPtr: // TODO default: xbt_die ("Unhandled form 0x%x, class 0x%X for DW_AT_start_scope of variable %s", - form, klass, name == NULL ? "?" : name); + form, (int) form_class, name == nullptr ? "?" : name); } } - if (ns && variable->global) { - char *old_name = variable->name; - variable->name = bprintf("%s::%s", ns, old_name); - free(old_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) { - variable->name = bprintf("@anonymous#%i", mc_anonymous_variable_index++); - } + if (variable->name.empty()) + variable->name = + "@anonymous#" + std::to_string(mc_anonymous_variable_index++); return variable; } -static void MC_dwarf_handle_variable_die(mc_object_info_t info, Dwarf_Die * die, - Dwarf_Die * unit, dw_frame_t frame, +static void MC_dwarf_handle_variable_die(simgrid::mc::ObjectInformation* info, Dwarf_Die * die, + Dwarf_Die * unit, simgrid::mc::Frame* frame, const char *ns) { - dw_variable_t variable = - MC_die_to_variable(info, die, unit, frame, ns); - if (variable == NULL) + std::unique_ptr variable = + MC_die_to_variable(info, die, unit, frame, ns); + if (!variable) return; - MC_dwarf_register_variable(info, frame, variable); -} - -static void mc_frame_free_voipd(dw_frame_t * p) -{ - mc_frame_free(*p); - *p = NULL; + // Those arrays are sorted later: + else 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(mc_object_info_t info, Dwarf_Die * die, - Dwarf_Die * unit, dw_frame_t parent_frame, +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); - mc_tag_class klass = MC_dwarf_tag_classify(tag); + simgrid::dwarf::TagClass klass = simgrid::dwarf::classify_tag(tag); // (Template) Subprogram declaration: - if (klass == mc_tag_subprogram + if (klass == simgrid::dwarf::TagClass::Subprogram && MC_dwarf_attr_flag(die, DW_AT_declaration, false)) return; - if (klass == mc_tag_scope) + if (klass == simgrid::dwarf::TagClass::Scope) xbt_assert(parent_frame, "No parent scope for this scope"); - dw_frame_t frame = xbt_new0(s_dw_frame_t, 1); - - frame->tag = tag; - frame->id = dwarf_dieoffset(die); - frame->object_info = info; + simgrid::mc::Frame frame; + frame.tag = tag; + frame.id = dwarf_dieoffset(die); + frame.object_info = info; - if (klass == mc_tag_subprogram) { + if (klass == simgrid::dwarf::TagClass::Subprogram) { const char *name = MC_dwarf_attr_integrate_string(die, DW_AT_name); - frame->name = - ns ? bprintf("%s::%s", ns, name) : xbt_strdup(name); + if (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); + 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 - void *base = info->base_address(); - - // Variables are filled in the (recursive) call of MC_dwarf_handle_children: - frame->variables = - xbt_dynar_new(sizeof(dw_variable_t), dw_variable_free_voidp); + 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->low_pc = low_pc ? ((char *) base) + low_pc : 0; + frame.range.begin() = low_pc ? (std::uint64_t) base + low_pc : 0; if (low_pc) { // DW_AT_high_pc: Dwarf_Attribute attr; - if (!dwarf_attr_integrate(die, DW_AT_high_pc, &attr)) { + if (!dwarf_attr_integrate(die, DW_AT_high_pc, &attr)) xbt_die("Missing DW_AT_high_pc matching with DW_AT_low_pc"); - } Dwarf_Sword offset; Dwarf_Addr high_pc; - switch (MC_dwarf_form_get_class(dwarf_whatform(&attr))) { + switch (simgrid::dwarf::classify_form(dwarf_whatform(&attr))) { // DW_AT_high_pc if an offset from the low_pc: - case MC_DW_CLASS_CONSTANT: + case simgrid::dwarf::FormClass::Constant: if (dwarf_formsdata(&attr, &offset) != 0) xbt_die("Could not read constant"); - frame->high_pc = (void *) ((char *) frame->low_pc + offset); + frame.range.end() = frame.range.begin() + offset; break; // DW_AT_high_pc is a relocatable address: - case MC_DW_CLASS_ADDRESS: + case simgrid::dwarf::FormClass::Address: if (dwarf_formaddr(&attr, &high_pc) != 0) xbt_die("Could not read address"); - frame->high_pc = ((char *) base) + high_pc; + frame.range.end() = base + high_pc; break; default: @@ -908,80 +922,79 @@ static void MC_dwarf_handle_scope_die(mc_object_info_t info, Dwarf_Die * die, } } - if (klass == mc_tag_subprogram) { + if (klass == simgrid::dwarf::TagClass::Subprogram) { Dwarf_Attribute attr_frame_base; if (dwarf_attr_integrate(die, DW_AT_frame_base, &attr_frame_base)) - mc_dwarf_location_list_init(&frame->frame_base, info, die, - &attr_frame_base); + frame.frame_base_location = simgrid::dwarf::location_list(*info, + attr_frame_base); } - frame->scopes = - xbt_dynar_new(sizeof(dw_frame_t), (void_f_pvoid_t) mc_frame_free_voipd); + // Handle children: + MC_dwarf_handle_children(info, die, unit, &frame, ns); + + // We sort them in order to have an (somewhat) efficient by name + // lookup: + std::sort(frame.variables.begin(), frame.variables.end(), + MC_compare_variable); // Register it: - if (klass == mc_tag_subprogram) { - char *key = bprintf("%" PRIx64, (uint64_t) frame->id); - xbt_dict_set(info->subprograms, key, frame, NULL); - xbt_free(key); - } else if (klass == mc_tag_scope) { - xbt_dynar_push(parent_frame->scopes, &frame); - } - // Handle children: - MC_dwarf_handle_children(info, die, unit, frame, ns); + 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(mc_object_info_t info, +static void mc_dwarf_handle_namespace_die(simgrid::mc::ObjectInformation* info, Dwarf_Die * die, Dwarf_Die * unit, - dw_frame_t frame, + simgrid::mc::Frame* frame, const char *ns) { const char *name = MC_dwarf_attr_integrate_string(die, DW_AT_name); if (frame) xbt_die("Unexpected namespace in a subprogram"); - char *new_ns = ns == NULL ? xbt_strdup(name) + 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(mc_object_info_t info, Dwarf_Die * die, - Dwarf_Die * unit, dw_frame_t frame, +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)) { + res = dwarf_siblingof(&child, &child)) MC_dwarf_handle_die(info, &child, unit, frame, ns); - } } -static void MC_dwarf_handle_die(mc_object_info_t info, Dwarf_Die * die, - Dwarf_Die * unit, dw_frame_t frame, +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); - mc_tag_class klass = MC_dwarf_tag_classify(tag); + simgrid::dwarf::TagClass klass = simgrid::dwarf::classify_tag(tag); switch (klass) { // Type: - case mc_tag_type: + case simgrid::dwarf::TagClass::Type: MC_dwarf_handle_type_die(info, die, unit, frame, ns); break; // Subprogram or scope: - case mc_tag_subprogram: - case mc_tag_scope: + case simgrid::dwarf::TagClass::Subprogram: + case simgrid::dwarf::TagClass::Scope: MC_dwarf_handle_scope_die(info, die, unit, frame, ns); return; // Variable: - case mc_tag_variable: + case simgrid::dwarf::TagClass::Variable: MC_dwarf_handle_variable_die(info, die, unit, frame, ns); break; - case mc_tag_namespace: + case simgrid::dwarf::TagClass::Namespace: mc_dwarf_handle_namespace_die(info, die, unit, frame, ns); break; @@ -991,150 +1004,229 @@ static void MC_dwarf_handle_die(mc_object_info_t info, Dwarf_Die * die, } } -/** \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. - */ -void MC_dwarf_get_variables(mc_object_info_t info) +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) { - int fd = open(info->file_name, O_RDONLY); - if (fd < 0) { - xbt_die("Could not open file %s", info->file_name); - } - Dwarf *dwarf = dwarf_begin(fd, DWARF_C_READ); - if (dwarf == NULL) { - xbt_die("Your program must be compiled with -g (%s)", info->file_name); - } // For each compilation unit: Dwarf_Off offset = 0; Dwarf_Off next_offset = 0; size_t length; - while (dwarf_nextcu(dwarf, offset, &next_offset, &length, NULL, 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) != NULL) { - - // For each child DIE: - Dwarf_Die child; - int res; - for (res = dwarf_child(&unit_die, &child); res == 0; - res = dwarf_siblingof(&child, &child)) { - MC_dwarf_handle_die(info, &child, &unit_die, NULL, NULL); - } - - } + if (dwarf_offdie(dwarf, offset + length, &unit_die) != nullptr) + MC_dwarf_handle_children(info, &unit_die, &unit_die, nullptr, nullptr); offset = next_offset; } - - dwarf_end(dwarf); - close(fd); } -/************************** Free functions *************************/ - -void mc_frame_free(dw_frame_t frame) +/** 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 get_build_id(Elf* elf) { - xbt_free(frame->name); - mc_dwarf_location_list_clear(&(frame->frame_base)); - xbt_dynar_free(&(frame->variables)); - xbt_dynar_free(&(frame->scopes)); - xbt_free(frame); -} + size_t phnum; + if (elf_getphdrnum (elf, &phnum) != 0) + xbt_die("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; -static void dw_type_free(mc_type_t t) -{ - delete t; -} + 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 (1) { + GElf_Nhdr nhdr; + 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): + 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: + char* start = (char*) data->d_buf + desc_pos; + char* end = (char*) start + nhdr.n_descsz; + return std::vector(start, end); -void dw_variable_free(dw_variable_t v) -{ - if (v) { - xbt_free(v->name); - xbt_free(v->type_origin); + } + } - if (v->locations.locations) - mc_dwarf_location_list_clear(&v->locations); - xbt_free(v); } + return std::vector(); } -void dw_variable_free_voidp(void *t) +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 to_hex(std::uint8_t byte) { - dw_variable_free((dw_variable_t) * (void **) t); + // Horrid double braces! + // Apparently, this is needed in C++11 (not in C++14). + return { { hexdigits[byte >> 4], hexdigits[byte & 0xF] } }; } -// ***** object_info - -namespace simgrid { -namespace mc { - -ObjectInformation::ObjectInformation() +/** Binary data to hexadecimal */ +static +std::string to_hex(const char* data, std::size_t count) { - this->flags = 0; - this->file_name = nullptr; - this->start = nullptr; - this->end = nullptr; - this->start_exec = nullptr; - this->end_exec = nullptr; - this->start_rw = nullptr; - this->end_rw = nullptr; - this->start_ro = nullptr; - this->end_ro = nullptr; - this->subprograms = xbt_dict_new_homogeneous((void (*)(void *)) mc_frame_free); - this->global_variables = - xbt_dynar_new(sizeof(dw_variable_t), dw_variable_free_voidp); - this->types = xbt_dict_new_homogeneous((void (*)(void *)) dw_type_free); - this->full_types_by_name = xbt_dict_new_homogeneous(NULL); - this->functions_index = nullptr; + std::string res; + res.resize(2*count); + for (std::size_t i = 0; i < count; i++) { + std::array hex_byte = to_hex(data[i]); + for (int j = 0; j < 2; ++j) + res[2 * i + j] = hex_byte[j]; + } + return res; } -ObjectInformation::~ObjectInformation() +/** Binary data to hexadecimal */ +static +std::string to_hex(std::vector const& data) { - xbt_free(this->file_name); - xbt_dict_free(&this->subprograms); - xbt_dynar_free(&this->global_variables); - xbt_dict_free(&this->types); - xbt_dict_free(&this->full_types_by_name); - xbt_dynar_free(&this->functions_index); + return to_hex(data.data(), data.size()); } -/** Find the DWARF offset for this ELF object - * - * An offset is applied to address found in DWARF: +/** 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 * - *
    - *
  • for an executable obejct, addresses are virtual address - * (there is no offset) i.e. \f$\text{virtual address} = \{dwarf address}\f$;
    • - *
  • for a shared object, the addreses are offset from the begining - * of the shared object (the base address of the mapped shared - * object must be used as offset - * i.e. \f$\text{virtual address} = \text{shared object base address} - * + \text{dwarf address}\f$.
    • + * This is one of the mechanisms used for + * [separate debug files](https://sourceware.org/gdb/onlinedocs/gdb/Separate-Debug-Files.html). + */ +static +std::string find_by_build_id(std::vector id) +{ + std::string filename; + for (const char* debug_path : debug_paths) { + filename = debug_path; + filename += ".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 filename; + } + 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. */ -void *ObjectInformation::base_address() const +static +void MC_dwarf_get_variables(simgrid::mc::ObjectInformation* info) { - if (this->executable()) - return nullptr; + if (elf_version(EV_CURRENT) == EV_NONE) + xbt_die("libelf initialization error"); + + // Open the ELF file: + int fd = open(info->file_name.c_str(), O_RDONLY); + if (fd < 0) + 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"); + Elf_Kind kind = elf_kind(elf); + if (kind != ELF_K_ELF) + xbt_die("Not an ELF file 2"); + + // Remember if this is a `ET_EXEC` (fixed location) or `ET_DYN` (relocatable): + 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); - void *result = this->start_exec; - if (this->start_rw != NULL && result > (void *) this->start_rw) - result = this->start_rw; - if (this->start_ro != NULL && result > (void *) this->start_ro) - result = this->start_ro; - return result; -} + // If there was no DWARF in the file, try to find it in a separate file + // with NT_GNU_BUILD_ID: + std::vector build_id = get_build_id(elf); + if (!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); + if (debug_file.empty()) { + std::string hex = to_hex(build_id); + 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()); + } -} -} + // 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); + if (fd < 0) + xbt_die("Could not open file %s", debug_file.c_str()); + Dwarf* dwarf = dwarf_begin(fd, DWARF_C_READ); + if (dwarf == nullptr) + xbt_die("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 debug-link. + // Is this method really used anywhere? -// ***** Helpers + xbt_die("Debugging information not found for %s\n" + "Try recompiling with -g\n", + info->file_name.c_str()); +} // ***** Functions index -static int MC_compare_frame_index_items(mc_function_index_item_t a, - mc_function_index_item_t b) +static int MC_compare_frame_index_items(simgrid::mc::FunctionIndexEntry* a, + simgrid::mc::FunctionIndexEntry* b) { if (a->low_pc < b->low_pc) return -1; @@ -1144,261 +1236,230 @@ static int MC_compare_frame_index_items(mc_function_index_item_t a, return 1; } -static void MC_make_functions_index(mc_object_info_t info) +static void MC_make_functions_index(simgrid::mc::ObjectInformation* info) { - xbt_dynar_t index = xbt_dynar_new(sizeof(s_mc_function_index_item_t), NULL); - - // Populate the array: - dw_frame_t frame = NULL; - xbt_dict_cursor_t cursor; - char *key; - xbt_dict_foreach(info->subprograms, cursor, key, frame) { - if (frame->low_pc == NULL) + info->functions_index.clear(); + + for (auto& e : info->subprograms) { + if (e.second.range.begin() == 0) continue; - s_mc_function_index_item_t entry; - entry.low_pc = frame->low_pc; - entry.high_pc = frame->high_pc; - entry.function = frame; - xbt_dynar_push(index, &entry); + simgrid::mc::FunctionIndexEntry entry; + entry.low_pc = (void*) e.second.range.begin(); + entry.function = &e.second; + info->functions_index.push_back(entry); } - mc_function_index_item_t base = - (mc_function_index_item_t) xbt_dynar_get_ptr(index, 0); + info->functions_index.shrink_to_fit(); // Sort the array by low_pc: - qsort(base, - xbt_dynar_length(index), - sizeof(s_mc_function_index_item_t), - (int (*)(const void *, const void *)) MC_compare_frame_index_items); - - info->functions_index = index; + std::sort(info->functions_index.begin(), info->functions_index.end(), + [](simgrid::mc::FunctionIndexEntry const& a, + simgrid::mc::FunctionIndexEntry const& b) + { + return a.low_pc < b.low_pc; + }); } -static void MC_post_process_variables(mc_object_info_t info) +static void MC_post_process_variables(simgrid::mc::ObjectInformation* info) { - unsigned cursor = 0; - dw_variable_t variable = NULL; - xbt_dynar_foreach(info->global_variables, cursor, variable) { - if (variable->type_origin) { - variable->type = (mc_type_t) xbt_dict_get_or_null(info->types, variable->type_origin); - } - } + // Someone needs this to be sorted but who? + std::sort(info->global_variables.begin(), info->global_variables.end(), + 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(mc_object_info_t info, dw_frame_t scope) +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: - char *key = bprintf("%" PRIx64, (uint64_t) scope->abstract_origin_id); - dw_frame_t abstract_origin = (dw_frame_t) xbt_dict_get_or_null(info->subprograms, key); - xbt_assert(abstract_origin, "Could not lookup abstract origin %s", key); - xbt_free(key); - scope->name = xbt_strdup(abstract_origin->name); - + 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: - unsigned cursor = 0; - dw_variable_t variable = NULL; - xbt_dynar_foreach(scope->variables, cursor, variable) { - if (variable->type_origin) { - variable->type = (mc_type_t) xbt_dict_get_or_null(info->types, variable->type_origin); - } - } + 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: - dw_frame_t nested_scope = NULL; - xbt_dynar_foreach(scope->scopes, cursor, nested_scope) - mc_post_process_scope(info, nested_scope); + for (simgrid::mc::Frame& nested_scope : scope->scopes) + mc_post_process_scope(info, &nested_scope); } -static void MC_post_process_functions(mc_object_info_t info) +static +simgrid::mc::Type* MC_resolve_type( + simgrid::mc::ObjectInformation* info, unsigned type_id) { - xbt_dict_cursor_t cursor; - char *key; - dw_frame_t subprogram = NULL; - xbt_dict_foreach(info->subprograms, cursor, key, subprogram) { - mc_post_process_scope(info, subprogram); - } -} + if (!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; -/** \brief Fill/lookup the "subtype" field. - */ -static void MC_resolve_subtype(mc_object_info_t info, mc_type_t type) -{ + // Don't have a name, we can't find a more complete version: + if (type->name.empty()) + return type; - if (type->dw_type_id.empty()) - return; - type->subtype = (mc_type_t) xbt_dict_get_or_null( - info->types, type->dw_type_id.c_str()); - if (type->subtype == NULL) - return; - if (type->subtype->byte_size != 0) - return; - if (type->subtype->name.empty()) - return; // Try to find a more complete description of the type: // We need to fix in order to support C++. - - mc_type_t subtype = - (mc_type_t) xbt_dict_get_or_null( - info->full_types_by_name, type->subtype->name.c_str()); - if (subtype != NULL) { - type->subtype = subtype; - } - + 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(mc_object_info_t info) +static void MC_post_process_types(simgrid::mc::ObjectInformation* info) { - xbt_dict_cursor_t cursor = NULL; - char *origin; - mc_type_t type; - // Lookup "subtype" field: - xbt_dict_foreach(info->types, cursor, origin, type) { - MC_resolve_subtype(info, type); - - mc_type_t member; - unsigned int i = 0; - if (type->members != NULL) - xbt_dynar_foreach(type->members, i, member) { - MC_resolve_subtype(info, member); - } + 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 MC_find_object_info( - std::vector const& maps, const char *name, int executable) +std::shared_ptr createObjectInformation( + std::vector const& maps, const char *name) { - std::shared_ptr result = - std::make_shared(); - if (executable) - result->flags |= MC_OBJECT_INFO_EXECUTABLE; - result->file_name = xbt_strdup(name); - MC_find_object_address(maps, result.get()); + std::shared_ptr result = + std::make_shared(); + result->file_name = name; + simgrid::mc::find_object_address(maps, result.get()); MC_dwarf_get_variables(result.get()); - MC_post_process_types(result.get()); MC_post_process_variables(result.get()); - MC_post_process_functions(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; } /*************************************************************************/ -static int MC_dwarf_get_variable_index(xbt_dynar_t variables, char *var, - void *address) +void postProcessObjectInformation(simgrid::mc::Process* process, simgrid::mc::ObjectInformation* info) { + for (auto& i : info->types) { - if (xbt_dynar_is_empty(variables)) - return 0; - - unsigned int cursor = 0; - int start = 0; - int end = xbt_dynar_length(variables) - 1; - dw_variable_t var_test = NULL; - - while (start <= end) { - cursor = (start + end) / 2; - var_test = - (dw_variable_t) xbt_dynar_get_as(variables, cursor, dw_variable_t); - if (strcmp(var_test->name, var) < 0) { - start = cursor + 1; - } else if (strcmp(var_test->name, var) > 0) { - end = cursor - 1; - } else { - if (address) { /* global variable */ - if (var_test->address == address) - return -1; - if (var_test->address > address) - end = cursor - 1; - else - start = cursor + 1; - } else { /* local variable */ - return -1; - } - } - } - - if (strcmp(var_test->name, var) == 0) { - if (address && var_test->address < address) - return cursor + 1; - else - return cursor; - } else if (strcmp(var_test->name, var) < 0) - return cursor + 1; - else - return cursor; - -} - -void MC_dwarf_register_global_variable(mc_object_info_t info, - dw_variable_t variable) -{ - int index = - MC_dwarf_get_variable_index(info->global_variables, variable->name, - variable->address); - if (index != -1) - xbt_dynar_insert_at(info->global_variables, index, &variable); - // TODO, else ? -} - -void MC_dwarf_register_non_global_variable(mc_object_info_t info, - dw_frame_t frame, - dw_variable_t variable) -{ - xbt_assert(frame, "Frame is NULL"); - int index = - MC_dwarf_get_variable_index(frame->variables, variable->name, NULL); - if (index != -1) - xbt_dynar_insert_at(frame->variables, index, &variable); - // TODO, else ? -} - -void MC_dwarf_register_variable(mc_object_info_t info, dw_frame_t frame, - dw_variable_t variable) -{ - if (variable->global) - MC_dwarf_register_global_variable(info, variable); - else if (frame == NULL) - xbt_die("No frame for this local variable"); - else - MC_dwarf_register_non_global_variable(info, frame, variable); -} - -void MC_post_process_object_info(mc_process_t process, mc_object_info_t info) -{ - xbt_dict_cursor_t cursor = NULL; - char *key = NULL; - mc_type_t type = NULL; - xbt_dict_foreach(info->types, cursor, key, type) { - - mc_type_t subtype = type; - while (subtype->type == DW_TAG_typedef || subtype->type == DW_TAG_volatile_type - || subtype->type == DW_TAG_const_type) { + simgrid::mc::Type* type = &(i.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 (!subtype->name.empty() && subtype->byte_size == 0) { + if (!subtype->name.empty() && subtype->byte_size == 0) for (auto const& object_info : process->object_infos) { - mc_type_t same_type = (mc_type_t) - xbt_dict_get_or_null(object_info->full_types_by_name, - subtype->name.c_str()); - if (same_type && !same_type->name.empty() && same_type->byte_size) { - type->full_type = same_type; + auto i = object_info->full_types_by_name.find(subtype->name); + if (i != object_info->full_types_by_name.end() + && !i->second->name.empty() && i->second->byte_size) { + type->full_type = i->second; break; } } - } else type->full_type = subtype; + else type->full_type = subtype; } } + +} +} + +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 + * convertion. + */ +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__) + // Could'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 +} + +} +}