X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/7da2926d0733ff0683f31aeea176ce71e127264f..7a09e5523184d3d38ac040b732ed60d91308004e:/src/mc/mc_dwarf.cpp diff --git a/src/mc/mc_dwarf.cpp b/src/mc/mc_dwarf.cpp index 4d1aef5147..3d086788f7 100644 --- a/src/mc/mc_dwarf.cpp +++ b/src/mc/mc_dwarf.cpp @@ -7,27 +7,30 @@ #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 +#include "src/simgrid/util.hpp" #include #include -#include +#include "src/mc/mc_private.h" +#include "src/mc/mc_dwarf.hpp" -#include "mc_object_info.h" -#include "mc_private.h" - -#include "mc/Process.hpp" -#include "mc/ObjectInformation.hpp" -#include "mc/Variable.hpp" +#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"); @@ -35,7 +38,7 @@ XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_dwarf, mc, "DWARF processing"); * * The default for a given language is defined in the DWARF spec. * - * \param language consant as defined by the DWARf spec + * \param language constant as defined by the DWARf spec */ static uint64_t MC_dwarf_default_lower_bound(int lang); @@ -64,7 +67,7 @@ static uint64_t MC_dwarf_array_element_count(Dwarf_Die * die, Dwarf_Die * unit); * \param info the resulting object fot the library/binary file (output) * \param die the current DIE * \param unit the DIE of the compile unit of the current DIE - * \param frame containg frame if any + * \param frame containing frame if any */ static void MC_dwarf_handle_die(simgrid::mc::ObjectInformation* info, Dwarf_Die * die, Dwarf_Die * unit, simgrid::mc::Frame* frame, @@ -76,12 +79,12 @@ static void MC_dwarf_handle_type_die(simgrid::mc::ObjectInformation* info, Dwarf Dwarf_Die * unit, simgrid::mc::Frame* frame, const char *ns); -/** \brief Calls MC_dwarf_handle_die on all childrend of the given die +/** \brief Calls MC_dwarf_handle_die on all children of the given die * * \param info the resulting object fot the library/binary file (output) * \param die the current DIE * \param unit the DIE of the compile unit of the current DIE - * \param frame containg frame if any + * \param frame containing frame if any */ static void MC_dwarf_handle_children(simgrid::mc::ObjectInformation* info, Dwarf_Die * die, Dwarf_Die * unit, simgrid::mc::Frame* frame, @@ -92,7 +95,7 @@ static void MC_dwarf_handle_children(simgrid::mc::ObjectInformation* info, Dwarf * \param info the resulting object fot the library/binary file (output) * \param die the current DIE * \param unit the DIE of the compile unit of the current DIE - * \param frame containg frame if any + * \param frame containing frame if any */ static void MC_dwarf_handle_variable_die(simgrid::mc::ObjectInformation* info, Dwarf_Die * die, Dwarf_Die * unit, simgrid::mc::Frame* frame, @@ -101,22 +104,40 @@ static void MC_dwarf_handle_variable_die(simgrid::mc::ObjectInformation* info, D /** \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 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) { @@ -143,44 +164,30 @@ 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. @@ -188,42 +195,43 @@ 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; } } @@ -232,9 +240,13 @@ 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 @@ -249,11 +261,10 @@ 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. @@ -264,7 +275,7 @@ 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) { @@ -281,7 +292,7 @@ static Dwarf_Off MC_dwarf_attr_dieoffset(Dwarf_Die * die, int attribute) return 0; dwarf_attr_integrate(die, attribute, &attr); Dwarf_Die subtype_die; - if (dwarf_formref_die(&attr, &subtype_die) == NULL) + if (dwarf_formref_die(&attr, &subtype_die) == nullptr) xbt_die("Could not find DIE"); return dwarf_dieoffset(&subtype_die); } @@ -294,7 +305,7 @@ static Dwarf_Off MC_dwarf_attr_integrate_dieoffset(Dwarf_Die * die, return 0; dwarf_attr_integrate(die, DW_AT_type, &attr); Dwarf_Die subtype_die; - if (dwarf_formref_die(&attr, &subtype_die) == NULL) + if (dwarf_formref_die(&attr, &subtype_die) == nullptr) xbt_die("Could not find DIE"); return dwarf_dieoffset(&subtype_die); } @@ -302,7 +313,7 @@ static Dwarf_Off MC_dwarf_attr_integrate_dieoffset(Dwarf_Die * 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 std::uint64_t MC_dwarf_at_type(Dwarf_Die * die) @@ -313,7 +324,7 @@ std::uint64_t MC_dwarf_at_type(Dwarf_Die * die) 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) @@ -326,7 +337,7 @@ 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), @@ -342,7 +353,8 @@ 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; } @@ -398,7 +410,7 @@ 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)) @@ -433,7 +445,7 @@ 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; @@ -493,10 +505,10 @@ static void MC_dwarf_fill_member_location( 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; @@ -506,10 +518,10 @@ static void MC_dwarf_fill_member_location( ("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::mc::DwarfExpression(expr, expr+len); + 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; @@ -521,15 +533,15 @@ static void MC_dwarf_fill_member_location( (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); } } @@ -562,11 +574,35 @@ static void MC_dwarf_add_members(simgrid::mc::ObjectInformation* info, Dwarf_Die // TODO, we should use another type (because is is not a type but a member) simgrid::mc::Member member; - member.inheritance = tag == DW_TAG_inheritance; + if (tag == DW_TAG_inheritance) + member.flags |= simgrid::mc::Member::INHERITANCE_FLAG; const char *name = MC_dwarf_attr_integrate_string(&child, DW_AT_name); if (name) member.name = name; + // Those base names are used by GCC and clang for virtual table pointers + // respectively ("__vptr$ClassName", "__vptr.ClassName"): + if (boost::algorithm::starts_with(member.name, "__vptr$") || + boost::algorithm::starts_with(member.name, "__vptr.")) + member.flags |= simgrid::mc::Member::VIRTUAL_POINTER_FLAG; + // A cleaner solution would be to check against the type: + // --- + // tag: DW_TAG_member + // name: "_vptr$Foo" + // type: + // # Type for a pointer to a vtable + // tag: DW_TAG_pointer_type + // type: + // # Type for a vtable: + // tag: DW_TAG_pointer_type + // name: "__vtbl_ptr_type" + // type: + // tag: DW_TAG_subroutine_type + // type: + // tag: DW_TAG_base_type + // name: "int" + // --- + member.byte_size = MC_dwarf_attr_integrate_uint(&child, DW_AT_byte_size, 0); member.type_id = MC_dwarf_at_type(&child); @@ -622,7 +658,7 @@ static simgrid::mc::Type MC_dwarf_die_to_type( } 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); @@ -657,21 +693,20 @@ static simgrid::mc::Type MC_dwarf_die_to_type( 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()) + 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); break; } - return std::move(type); + return type; } static void MC_dwarf_handle_type_die(simgrid::mc::ObjectInformation* info, Dwarf_Die * die, @@ -700,14 +735,14 @@ static std::unique_ptr MC_die_to_variable( 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 nullptr; std::unique_ptr variable = std::unique_ptr(new simgrid::mc::Variable()); - variable->dwarf_offset = dwarf_dieoffset(die); - variable->global = frame == NULL; // Can be override base on DW_AT_location + 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); @@ -716,12 +751,14 @@ static std::unique_ptr MC_die_to_variable( 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; @@ -730,35 +767,34 @@ static std::unique_ptr MC_die_to_variable( xbt_die( "Could not read location expression in DW_AT_location " "of variable <%" PRIx64 ">%s", - (uint64_t) variable->dwarf_offset, + (uint64_t) variable->id, variable->name.c_str()); } if (len == 1 && expr[0].atom == DW_OP_addr) { - variable->global = 1; + variable->global = true; uintptr_t offset = (uintptr_t) expr[0].number; uintptr_t base = (uintptr_t) info->base_address(); variable->address = (void *) (base + offset); - } else { - simgrid::mc::LocationListEntry entry; - entry.expression = {expr, expr + len}; - variable->location_list = { std::move(entry) }; - } + } 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->location_list, 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, + form, form, (int) form_class, (int) form_class, + (uint64_t) variable->id, variable->name.c_str()); } @@ -767,20 +803,21 @@ static std::unique_ptr MC_die_to_variable( 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); } } @@ -794,7 +831,7 @@ static std::unique_ptr MC_die_to_variable( variable->name = "@anonymous#" + std::to_string(mc_anonymous_variable_index++); - return std::move(variable); + return variable; } static void MC_dwarf_handle_variable_die(simgrid::mc::ObjectInformation* info, Dwarf_Die * die, @@ -820,30 +857,27 @@ static void MC_dwarf_handle_scope_die(simgrid::mc::ObjectInformation* info, Dwar { // 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"); 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); - if(ns) + if (ns) frame.name = std::string(ns) + "::" + name; else if (name) frame.name = name; - else - frame.name.clear(); } frame.abstract_origin_id = @@ -852,36 +886,35 @@ static void MC_dwarf_handle_scope_die(simgrid::mc::ObjectInformation* info, Dwar // 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(); + 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: @@ -890,24 +923,24 @@ static void MC_dwarf_handle_scope_die(simgrid::mc::ObjectInformation* info, Dwar } } - 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); } // Handle children: MC_dwarf_handle_children(info, die, unit, &frame, ns); - // Someone needs this to be sorted but who? - std::sort(frame.variables.begin(), frame.variables.end(), - MC_compare_variable); + // 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 == mc_tag_subprogram) - info->subprograms[frame.id] = frame; - else if (klass == mc_tag_scope) + 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)); } @@ -919,7 +952,7 @@ static void mc_dwarf_handle_namespace_die(simgrid::mc::ObjectInformation* info, 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); @@ -933,9 +966,8 @@ static void MC_dwarf_handle_children(simgrid::mc::ObjectInformation* info, Dwarf 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(simgrid::mc::ObjectInformation* info, Dwarf_Die * die, @@ -943,26 +975,26 @@ static void MC_dwarf_handle_die(simgrid::mc::ObjectInformation* info, Dwarf_Die 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; @@ -972,37 +1004,239 @@ static void MC_dwarf_handle_die(simgrid::mc::ObjectInformation* info, Dwarf_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(simgrid::mc::ObjectInformation* 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.c_str(), O_RDONLY); - if (fd < 0) - xbt_die("Could not open file %s", info->file_name.c_str()); - Dwarf *dwarf = dwarf_begin(fd, DWARF_C_READ); - if (dwarf == NULL) - xbt_die("Missing debugging information in %s\n" - "Your program and its dependencies must have debugging information.\n" - "You might want to recompile with -g or install the suitable debugging package.\n", - info->file_name.c_str()); // 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) - MC_dwarf_handle_children(info, &unit_die, &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; } +} +/** 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) +{ + // Summary: the GNU build ID is stored in a ("GNU, NT_GNU_BUILD_ID) note + // found in a PT_NOTE entry in the program header table. + + size_t phnum; + if (elf_getphdrnum (elf, &phnum) != 0) + xbt_die("Could not read program headers"); + + // Iterate over the 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(start, end); + } + } + + } + return std::vector(); +} + +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) +{ + // 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 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 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 id) +{ + std::string filename; + std::string hex = to_hex(id); + for (const char* 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) +{ + 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"); + Elf_Kind kind = elf_kind(elf); + if (kind != ELF_K_ELF) + xbt_die("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 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 .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 @@ -1023,10 +1257,10 @@ static void MC_make_functions_index(simgrid::mc::ObjectInformation* info) info->functions_index.clear(); for (auto& e : info->subprograms) { - if (e.second.low_pc == nullptr) + if (e.second.range.begin() == 0) continue; simgrid::mc::FunctionIndexEntry entry; - entry.low_pc = e.second.low_pc; + entry.low_pc = (void*) e.second.range.begin(); entry.function = &e.second; info->functions_index.push_back(entry); } @@ -1034,7 +1268,7 @@ static void MC_make_functions_index(simgrid::mc::ObjectInformation* info) info->functions_index.shrink_to_fit(); // Sort the array by low_pc: - std::sort(info->functions_index.begin(), info->functions_index.end(), + boost::range::sort(info->functions_index, [](simgrid::mc::FunctionIndexEntry const& a, simgrid::mc::FunctionIndexEntry const& b) { @@ -1045,8 +1279,7 @@ static void MC_make_functions_index(simgrid::mc::ObjectInformation* info) static void MC_post_process_variables(simgrid::mc::ObjectInformation* info) { // Someone needs this to be sorted but who? - std::sort(info->global_variables.begin(), info->global_variables.end(), - MC_compare_variable); + boost::range::sort(info->global_variables, MC_compare_variable); for(simgrid::mc::Variable& variable : info->global_variables) if (variable.type_id) @@ -1115,28 +1348,29 @@ static void MC_post_process_types(simgrid::mc::ObjectInformation* info) } } +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 |= simgrid::mc::ObjectInformation::Executable; result->file_name = name; - MC_find_object_address(maps, result.get()); - MC_dwarf_get_variables(result.get()); + 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 std::move(result); + return result; } /*************************************************************************/ -void MC_post_process_object_info(simgrid::mc::Process* process, simgrid::mc::ObjectInformation* info) +void postProcessObjectInformation(simgrid::mc::Process* process, simgrid::mc::ObjectInformation* info) { for (auto& i : info->types) { @@ -1151,7 +1385,7 @@ void MC_post_process_object_info(simgrid::mc::Process* process, simgrid::mc::Obj 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) { auto i = object_info->full_types_by_name.find(subtype->name); if (i != object_info->full_types_by_name.end() @@ -1160,7 +1394,87 @@ void MC_post_process_object_info(simgrid::mc::Process* process, simgrid::mc::Obj 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 + * 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 +} + +} +}