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- // gdb-index.cc -- generate .gdb_index section for fast debug lookup
- // Copyright (C) 2012-2022 Free Software Foundation, Inc.
- // Written by Cary Coutant <ccoutant@google.com>.
- // This file is part of gold.
- // This program is free software; you can redistribute it and/or modify
- // it under the terms of the GNU General Public License as published by
- // the Free Software Foundation; either version 3 of the License, or
- // (at your option) any later version.
- // This program is distributed in the hope that it will be useful,
- // but WITHOUT ANY WARRANTY; without even the implied warranty of
- // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- // GNU General Public License for more details.
- // You should have received a copy of the GNU General Public License
- // along with this program; if not, write to the Free Software
- // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
- // MA 02110-1301, USA.
- #include "gold.h"
- #include "gdb-index.h"
- #include "dwarf_reader.h"
- #include "dwarf.h"
- #include "object.h"
- #include "output.h"
- #include "demangle.h"
- namespace gold
- {
- const int gdb_index_version = 7;
- // Sizes of various records in the .gdb_index section.
- const int gdb_index_offset_size = 4;
- const int gdb_index_hdr_size = 6 * gdb_index_offset_size;
- const int gdb_index_cu_size = 16;
- const int gdb_index_tu_size = 24;
- const int gdb_index_addr_size = 16 + gdb_index_offset_size;
- const int gdb_index_sym_size = 2 * gdb_index_offset_size;
- // This class manages the hashed symbol table for the .gdb_index section.
- // It is essentially equivalent to the hashtab implementation in libiberty,
- // but is copied into gdb sources and here for compatibility because its
- // data structure is exposed on disk.
- template <typename T>
- class Gdb_hashtab
- {
- public:
- Gdb_hashtab()
- : size_(0), capacity_(0), hashtab_(NULL)
- { }
- ~Gdb_hashtab()
- {
- for (size_t i = 0; i < this->capacity_; ++i)
- if (this->hashtab_[i] != NULL)
- delete this->hashtab_[i];
- delete[] this->hashtab_;
- }
- // Add a symbol.
- T*
- add(T* symbol)
- {
- // Resize the hash table if necessary.
- if (4 * this->size_ / 3 >= this->capacity_)
- this->expand();
- T** slot = this->find_slot(symbol);
- if (*slot == NULL)
- {
- ++this->size_;
- *slot = symbol;
- }
- return *slot;
- }
- // Return the current size.
- size_t
- size() const
- { return this->size_; }
- // Return the current capacity.
- size_t
- capacity() const
- { return this->capacity_; }
- // Return the contents of slot N.
- T*
- operator[](size_t n)
- { return this->hashtab_[n]; }
- private:
- // Find a symbol in the hash table, or return an empty slot if
- // the symbol is not in the table.
- T**
- find_slot(T* symbol)
- {
- unsigned int index = symbol->hash() & (this->capacity_ - 1);
- unsigned int step = ((symbol->hash() * 17) & (this->capacity_ - 1)) | 1;
- for (;;)
- {
- if (this->hashtab_[index] == NULL
- || this->hashtab_[index]->equal(symbol))
- return &this->hashtab_[index];
- index = (index + step) & (this->capacity_ - 1);
- }
- }
- // Expand the hash table.
- void
- expand()
- {
- if (this->capacity_ == 0)
- {
- // Allocate the hash table for the first time.
- this->capacity_ = Gdb_hashtab::initial_size;
- this->hashtab_ = new T*[this->capacity_];
- memset(this->hashtab_, 0, this->capacity_ * sizeof(T*));
- }
- else
- {
- // Expand and rehash.
- unsigned int old_cap = this->capacity_;
- T** old_hashtab = this->hashtab_;
- this->capacity_ *= 2;
- this->hashtab_ = new T*[this->capacity_];
- memset(this->hashtab_, 0, this->capacity_ * sizeof(T*));
- for (size_t i = 0; i < old_cap; ++i)
- {
- if (old_hashtab[i] != NULL)
- {
- T** slot = this->find_slot(old_hashtab[i]);
- *slot = old_hashtab[i];
- }
- }
- delete[] old_hashtab;
- }
- }
- // Initial size of the hash table; must be a power of 2.
- static const int initial_size = 1024;
- size_t size_;
- size_t capacity_;
- T** hashtab_;
- };
- // The hash function for strings in the mapped index. This is copied
- // directly from gdb/dwarf2read.c.
- static unsigned int
- mapped_index_string_hash(const unsigned char* str)
- {
- unsigned int r = 0;
- unsigned char c;
- while ((c = *str++) != 0)
- {
- if (gdb_index_version >= 5)
- c = tolower (c);
- r = r * 67 + c - 113;
- }
- return r;
- }
- // A specialization of Dwarf_info_reader, for building the .gdb_index.
- class Gdb_index_info_reader : public Dwarf_info_reader
- {
- public:
- Gdb_index_info_reader(bool is_type_unit,
- Relobj* object,
- const unsigned char* symbols,
- off_t symbols_size,
- unsigned int shndx,
- unsigned int reloc_shndx,
- unsigned int reloc_type,
- Gdb_index* gdb_index)
- : Dwarf_info_reader(is_type_unit, object, symbols, symbols_size, shndx,
- reloc_shndx, reloc_type),
- gdb_index_(gdb_index), cu_index_(0), cu_language_(0)
- { }
- ~Gdb_index_info_reader()
- { this->clear_declarations(); }
- // Print usage statistics.
- static void
- print_stats();
- protected:
- // Visit a compilation unit.
- virtual void
- visit_compilation_unit(off_t cu_offset, off_t cu_length, Dwarf_die*);
- // Visit a type unit.
- virtual void
- visit_type_unit(off_t tu_offset, off_t tu_length, off_t type_offset,
- uint64_t signature, Dwarf_die*);
- private:
- // A map for recording DIEs we've seen that may be referred to be
- // later DIEs (via DW_AT_specification or DW_AT_abstract_origin).
- // The map is indexed by a DIE offset within the compile unit.
- // PARENT_OFFSET_ is the offset of the DIE that represents the
- // outer context, and NAME_ is a pointer to a component of the
- // fully-qualified name.
- // Normally, the names we point to are in a string table, so we don't
- // have to manage them, but when we have a fully-qualified name
- // computed, we put it in the table, and set PARENT_OFFSET_ to -1
- // indicate a string that we are managing.
- struct Declaration_pair
- {
- Declaration_pair(off_t parent_offset, const char* name)
- : parent_offset_(parent_offset), name_(name)
- { }
- off_t parent_offset_;
- const char* name_;
- };
- typedef Unordered_map<off_t, Declaration_pair> Declaration_map;
- // Visit a top-level DIE.
- void
- visit_top_die(Dwarf_die* die);
- // Visit the children of a DIE.
- void
- visit_children(Dwarf_die* die, Dwarf_die* context);
- // Visit a DIE.
- void
- visit_die(Dwarf_die* die, Dwarf_die* context);
- // Visit the children of a DIE.
- void
- visit_children_for_decls(Dwarf_die* die);
- // Visit a DIE.
- void
- visit_die_for_decls(Dwarf_die* die, Dwarf_die* context);
- // Guess a fully-qualified name for a class type, based on member function
- // linkage names.
- std::string
- guess_full_class_name(Dwarf_die* die);
- // Add a declaration DIE to the table of declarations.
- void
- add_declaration(Dwarf_die* die, Dwarf_die* context);
- // Add a declaration whose fully-qualified name is already known.
- void
- add_declaration_with_full_name(Dwarf_die* die, const char* full_name);
- // Return the context for a DIE whose parent is at DIE_OFFSET.
- std::string
- get_context(off_t die_offset);
- // Construct a fully-qualified name for DIE.
- std::string
- get_qualified_name(Dwarf_die* die, Dwarf_die* context);
- // Record the address ranges for a compilation unit.
- void
- record_cu_ranges(Dwarf_die* die);
- // Wrapper for read_pubtable.
- bool
- read_pubnames_and_pubtypes(Dwarf_die* die);
- // Read the .debug_pubnames and .debug_pubtypes tables.
- bool
- read_pubtable(Dwarf_pubnames_table* table, off_t offset);
- // Clear the declarations map.
- void
- clear_declarations();
- // The Gdb_index section.
- Gdb_index* gdb_index_;
- // The current CU index (negative for a TU).
- int cu_index_;
- // The language of the current CU or TU.
- unsigned int cu_language_;
- // Map from DIE offset to (parent offset, name) pair,
- // for DW_AT_specification.
- Declaration_map declarations_;
- // Statistics.
- // Total number of DWARF compilation units processed.
- static unsigned int dwarf_cu_count;
- // Number of DWARF compilation units with pubnames/pubtypes.
- static unsigned int dwarf_cu_nopubnames_count;
- // Total number of DWARF type units processed.
- static unsigned int dwarf_tu_count;
- // Number of DWARF type units with pubnames/pubtypes.
- static unsigned int dwarf_tu_nopubnames_count;
- };
- // Total number of DWARF compilation units processed.
- unsigned int Gdb_index_info_reader::dwarf_cu_count = 0;
- // Number of DWARF compilation units without pubnames/pubtypes.
- unsigned int Gdb_index_info_reader::dwarf_cu_nopubnames_count = 0;
- // Total number of DWARF type units processed.
- unsigned int Gdb_index_info_reader::dwarf_tu_count = 0;
- // Number of DWARF type units without pubnames/pubtypes.
- unsigned int Gdb_index_info_reader::dwarf_tu_nopubnames_count = 0;
- // Process a compilation unit and parse its child DIE.
- void
- Gdb_index_info_reader::visit_compilation_unit(off_t cu_offset, off_t cu_length,
- Dwarf_die* root_die)
- {
- ++Gdb_index_info_reader::dwarf_cu_count;
- this->cu_index_ = this->gdb_index_->add_comp_unit(cu_offset, cu_length);
- this->visit_top_die(root_die);
- }
- // Process a type unit and parse its child DIE.
- void
- Gdb_index_info_reader::visit_type_unit(off_t tu_offset, off_t,
- off_t type_offset, uint64_t signature,
- Dwarf_die* root_die)
- {
- ++Gdb_index_info_reader::dwarf_tu_count;
- // Use a negative index to flag this as a TU instead of a CU.
- this->cu_index_ = -1 - this->gdb_index_->add_type_unit(tu_offset, type_offset,
- signature);
- this->visit_top_die(root_die);
- }
- // Process a top-level DIE.
- // For compile_unit DIEs, record the address ranges. For all
- // interesting tags, add qualified names to the symbol table
- // and process interesting children. We may need to process
- // certain children just for saving declarations that might be
- // referenced by later DIEs with a DW_AT_specification attribute.
- void
- Gdb_index_info_reader::visit_top_die(Dwarf_die* die)
- {
- this->clear_declarations();
- switch (die->tag())
- {
- case elfcpp::DW_TAG_compile_unit:
- case elfcpp::DW_TAG_type_unit:
- this->cu_language_ = die->int_attribute(elfcpp::DW_AT_language);
- if (die->tag() == elfcpp::DW_TAG_compile_unit)
- this->record_cu_ranges(die);
- // If there is a pubnames and/or pubtypes section for this
- // compilation unit, use those; otherwise, parse the DWARF
- // info to extract the names.
- if (!this->read_pubnames_and_pubtypes(die))
- {
- // Check for languages that require specialized knowledge to
- // construct fully-qualified names, that we don't yet support.
- if (this->cu_language_ == elfcpp::DW_LANG_Ada83
- || this->cu_language_ == elfcpp::DW_LANG_Fortran77
- || this->cu_language_ == elfcpp::DW_LANG_Fortran90
- || this->cu_language_ == elfcpp::DW_LANG_Java
- || this->cu_language_ == elfcpp::DW_LANG_Ada95
- || this->cu_language_ == elfcpp::DW_LANG_Fortran95
- || this->cu_language_ == elfcpp::DW_LANG_Fortran03
- || this->cu_language_ == elfcpp::DW_LANG_Fortran08)
- {
- gold_warning(_("%s: --gdb-index currently supports "
- "only C and C++ languages"),
- this->object()->name().c_str());
- return;
- }
- if (die->tag() == elfcpp::DW_TAG_compile_unit)
- ++Gdb_index_info_reader::dwarf_cu_nopubnames_count;
- else
- ++Gdb_index_info_reader::dwarf_tu_nopubnames_count;
- this->visit_children(die, NULL);
- }
- break;
- default:
- // The top level DIE should be one of the above.
- gold_warning(_("%s: top level DIE is not DW_TAG_compile_unit "
- "or DW_TAG_type_unit"),
- this->object()->name().c_str());
- return;
- }
- }
- // Visit the children of PARENT, looking for symbols to add to the index.
- // CONTEXT points to the DIE to use for constructing the qualified name --
- // NULL if PARENT is the top-level DIE; otherwise it is the same as PARENT.
- void
- Gdb_index_info_reader::visit_children(Dwarf_die* parent, Dwarf_die* context)
- {
- off_t next_offset = 0;
- for (off_t die_offset = parent->child_offset();
- die_offset != 0;
- die_offset = next_offset)
- {
- Dwarf_die die(this, die_offset, parent);
- if (die.tag() == 0)
- break;
- this->visit_die(&die, context);
- next_offset = die.sibling_offset();
- }
- }
- // Visit a child DIE, looking for symbols to add to the index.
- // CONTEXT is the parent DIE, used for constructing the qualified name;
- // it is NULL if the parent DIE is the top-level DIE.
- void
- Gdb_index_info_reader::visit_die(Dwarf_die* die, Dwarf_die* context)
- {
- switch (die->tag())
- {
- case elfcpp::DW_TAG_subprogram:
- case elfcpp::DW_TAG_constant:
- case elfcpp::DW_TAG_variable:
- case elfcpp::DW_TAG_enumerator:
- case elfcpp::DW_TAG_base_type:
- if (die->is_declaration())
- this->add_declaration(die, context);
- else
- {
- // If the DIE is not a declaration, add it to the index.
- std::string full_name = this->get_qualified_name(die, context);
- if (!full_name.empty())
- this->gdb_index_->add_symbol(this->cu_index_,
- full_name.c_str(), 0);
- }
- break;
- case elfcpp::DW_TAG_typedef:
- case elfcpp::DW_TAG_union_type:
- case elfcpp::DW_TAG_class_type:
- case elfcpp::DW_TAG_interface_type:
- case elfcpp::DW_TAG_structure_type:
- case elfcpp::DW_TAG_enumeration_type:
- case elfcpp::DW_TAG_subrange_type:
- case elfcpp::DW_TAG_namespace:
- {
- std::string full_name;
-
- // For classes at the top level, we need to look for a
- // member function with a linkage name in order to get
- // the properly-canonicalized name.
- if (context == NULL
- && (die->tag() == elfcpp::DW_TAG_class_type
- || die->tag() == elfcpp::DW_TAG_structure_type
- || die->tag() == elfcpp::DW_TAG_union_type))
- full_name.assign(this->guess_full_class_name(die));
- // Because we will visit the children, we need to add this DIE
- // to the declarations table.
- if (full_name.empty())
- this->add_declaration(die, context);
- else
- this->add_declaration_with_full_name(die, full_name.c_str());
- // If the DIE is not a declaration, add it to the index.
- // Gdb stores a namespace in the index even when it is
- // a declaration.
- if (die->tag() == elfcpp::DW_TAG_namespace
- || !die->is_declaration())
- {
- if (full_name.empty())
- full_name = this->get_qualified_name(die, context);
- if (!full_name.empty())
- this->gdb_index_->add_symbol(this->cu_index_,
- full_name.c_str(), 0);
- }
- // We're interested in the children only for namespaces and
- // enumeration types. For enumeration types, we do not include
- // the enumeration tag as part of the full name. For other tags,
- // visit the children only to collect declarations.
- if (die->tag() == elfcpp::DW_TAG_namespace
- || die->tag() == elfcpp::DW_TAG_enumeration_type)
- this->visit_children(die, die);
- else
- this->visit_children_for_decls(die);
- }
- break;
- default:
- break;
- }
- }
- // Visit the children of PARENT, looking only for declarations that
- // may be referenced by later specification DIEs.
- void
- Gdb_index_info_reader::visit_children_for_decls(Dwarf_die* parent)
- {
- off_t next_offset = 0;
- for (off_t die_offset = parent->child_offset();
- die_offset != 0;
- die_offset = next_offset)
- {
- Dwarf_die die(this, die_offset, parent);
- if (die.tag() == 0)
- break;
- this->visit_die_for_decls(&die, parent);
- next_offset = die.sibling_offset();
- }
- }
- // Visit a child DIE, looking only for declarations that
- // may be referenced by later specification DIEs.
- void
- Gdb_index_info_reader::visit_die_for_decls(Dwarf_die* die, Dwarf_die* context)
- {
- switch (die->tag())
- {
- case elfcpp::DW_TAG_subprogram:
- case elfcpp::DW_TAG_constant:
- case elfcpp::DW_TAG_variable:
- case elfcpp::DW_TAG_enumerator:
- case elfcpp::DW_TAG_base_type:
- {
- if (die->is_declaration())
- this->add_declaration(die, context);
- }
- break;
- case elfcpp::DW_TAG_typedef:
- case elfcpp::DW_TAG_union_type:
- case elfcpp::DW_TAG_class_type:
- case elfcpp::DW_TAG_interface_type:
- case elfcpp::DW_TAG_structure_type:
- case elfcpp::DW_TAG_enumeration_type:
- case elfcpp::DW_TAG_subrange_type:
- case elfcpp::DW_TAG_namespace:
- {
- if (die->is_declaration())
- this->add_declaration(die, context);
- this->visit_children_for_decls(die);
- }
- break;
- default:
- break;
- }
- }
- // Extract the class name from the linkage name of a member function.
- // This code is adapted from ../gdb/cp-support.c.
- #define d_left(dc) (dc)->u.s_binary.left
- #define d_right(dc) (dc)->u.s_binary.right
- static char*
- class_name_from_linkage_name(const char* linkage_name)
- {
- void* storage;
- struct demangle_component* tree =
- cplus_demangle_v3_components(linkage_name, DMGL_NO_OPTS, &storage);
- if (tree == NULL)
- return NULL;
- int done = 0;
- // First strip off any qualifiers, if we have a function or
- // method.
- while (!done)
- switch (tree->type)
- {
- case DEMANGLE_COMPONENT_CONST:
- case DEMANGLE_COMPONENT_RESTRICT:
- case DEMANGLE_COMPONENT_VOLATILE:
- case DEMANGLE_COMPONENT_CONST_THIS:
- case DEMANGLE_COMPONENT_RESTRICT_THIS:
- case DEMANGLE_COMPONENT_VOLATILE_THIS:
- case DEMANGLE_COMPONENT_VENDOR_TYPE_QUAL:
- tree = d_left(tree);
- break;
- default:
- done = 1;
- break;
- }
- // If what we have now is a function, discard the argument list.
- if (tree->type == DEMANGLE_COMPONENT_TYPED_NAME)
- tree = d_left(tree);
- // If what we have now is a template, strip off the template
- // arguments. The left subtree may be a qualified name.
- if (tree->type == DEMANGLE_COMPONENT_TEMPLATE)
- tree = d_left(tree);
- // What we have now should be a name, possibly qualified.
- // Additional qualifiers could live in the left subtree or the right
- // subtree. Find the last piece.
- done = 0;
- struct demangle_component* prev_comp = NULL;
- struct demangle_component* cur_comp = tree;
- while (!done)
- switch (cur_comp->type)
- {
- case DEMANGLE_COMPONENT_QUAL_NAME:
- case DEMANGLE_COMPONENT_LOCAL_NAME:
- prev_comp = cur_comp;
- cur_comp = d_right(cur_comp);
- break;
- case DEMANGLE_COMPONENT_TEMPLATE:
- case DEMANGLE_COMPONENT_NAME:
- case DEMANGLE_COMPONENT_CTOR:
- case DEMANGLE_COMPONENT_DTOR:
- case DEMANGLE_COMPONENT_OPERATOR:
- case DEMANGLE_COMPONENT_EXTENDED_OPERATOR:
- done = 1;
- break;
- default:
- done = 1;
- cur_comp = NULL;
- break;
- }
- char* ret = NULL;
- if (cur_comp != NULL && prev_comp != NULL)
- {
- // We want to discard the rightmost child of PREV_COMP.
- *prev_comp = *d_left(prev_comp);
- size_t allocated_size;
- ret = cplus_demangle_print(DMGL_NO_OPTS, tree, 30, &allocated_size);
- }
- free(storage);
- return ret;
- }
- // Guess a fully-qualified name for a class type, based on member function
- // linkage names. This is needed for class/struct/union types at the
- // top level, because GCC does not always properly embed them within
- // the namespace. As in gdb, we look for a member function with a linkage
- // name and extract the qualified name from the demangled name.
- std::string
- Gdb_index_info_reader::guess_full_class_name(Dwarf_die* die)
- {
- std::string full_name;
- off_t next_offset = 0;
-
- // This routine scans ahead in the DIE structure, possibly advancing
- // the relocation tracker beyond the current DIE. We need to checkpoint
- // the tracker and reset it when we're done.
- uint64_t checkpoint = this->get_reloc_checkpoint();
- for (off_t child_offset = die->child_offset();
- child_offset != 0;
- child_offset = next_offset)
- {
- Dwarf_die child(this, child_offset, die);
- if (child.tag() == 0)
- break;
- if (child.tag() == elfcpp::DW_TAG_subprogram)
- {
- const char* linkage_name = child.linkage_name();
- if (linkage_name != NULL)
- {
- char* guess = class_name_from_linkage_name(linkage_name);
- if (guess != NULL)
- {
- full_name.assign(guess);
- free(guess);
- break;
- }
- }
- }
- next_offset = child.sibling_offset();
- }
- this->reset_relocs(checkpoint);
- return full_name;
- }
- // Add a declaration DIE to the table of declarations.
- void
- Gdb_index_info_reader::add_declaration(Dwarf_die* die, Dwarf_die* context)
- {
- const char* name = die->name();
- off_t parent_offset = context != NULL ? context->offset() : 0;
- // If this DIE has a DW_AT_specification or DW_AT_abstract_origin
- // attribute, use the parent and name from the earlier declaration.
- off_t spec = die->specification();
- if (spec == 0)
- spec = die->abstract_origin();
- if (spec > 0)
- {
- Declaration_map::iterator it = this->declarations_.find(spec);
- if (it != this->declarations_.end())
- {
- parent_offset = it->second.parent_offset_;
- name = it->second.name_;
- }
- }
- if (name == NULL)
- {
- if (die->tag() == elfcpp::DW_TAG_namespace)
- name = "(anonymous namespace)";
- else if (die->tag() == elfcpp::DW_TAG_union_type)
- name = "(anonymous union)";
- else
- name = "(unknown)";
- }
- Declaration_pair decl(parent_offset, name);
- this->declarations_.insert(std::make_pair(die->offset(), decl));
- }
- // Add a declaration whose fully-qualified name is already known.
- // In the case where we had to get the canonical name by demangling
- // a linkage name, this ensures we use that name instead of the one
- // provided in DW_AT_name.
- void
- Gdb_index_info_reader::add_declaration_with_full_name(
- Dwarf_die* die,
- const char* full_name)
- {
- // We need to copy the name.
- int len = strlen(full_name);
- char* copy = new char[len + 1];
- memcpy(copy, full_name, len + 1);
- // Flag that we now manage the memory this points to.
- Declaration_pair decl(-1, copy);
- this->declarations_.insert(std::make_pair(die->offset(), decl));
- }
- // Return the context for a DIE whose parent is at DIE_OFFSET.
- std::string
- Gdb_index_info_reader::get_context(off_t die_offset)
- {
- std::string context;
- Declaration_map::iterator it = this->declarations_.find(die_offset);
- if (it != this->declarations_.end())
- {
- off_t parent_offset = it->second.parent_offset_;
- if (parent_offset > 0)
- {
- context = get_context(parent_offset);
- context.append("::");
- }
- if (it->second.name_ != NULL)
- context.append(it->second.name_);
- }
- return context;
- }
- // Construct the fully-qualified name for DIE.
- std::string
- Gdb_index_info_reader::get_qualified_name(Dwarf_die* die, Dwarf_die* context)
- {
- std::string full_name;
- const char* name = die->name();
- off_t parent_offset = context != NULL ? context->offset() : 0;
- // If this DIE has a DW_AT_specification or DW_AT_abstract_origin
- // attribute, use the parent and name from the earlier declaration.
- off_t spec = die->specification();
- if (spec == 0)
- spec = die->abstract_origin();
- if (spec > 0)
- {
- Declaration_map::iterator it = this->declarations_.find(spec);
- if (it != this->declarations_.end())
- {
- parent_offset = it->second.parent_offset_;
- name = it->second.name_;
- }
- }
- if (name == NULL && die->tag() == elfcpp::DW_TAG_namespace)
- name = "(anonymous namespace)";
- else if (name == NULL)
- return full_name;
- // If this is an enumerator constant, skip the immediate parent,
- // which is the enumeration tag.
- if (die->tag() == elfcpp::DW_TAG_enumerator)
- {
- Declaration_map::iterator it = this->declarations_.find(parent_offset);
- if (it != this->declarations_.end())
- parent_offset = it->second.parent_offset_;
- }
- if (parent_offset > 0)
- {
- full_name.assign(this->get_context(parent_offset));
- full_name.append("::");
- }
- full_name.append(name);
- return full_name;
- }
- // Record the address ranges for a compilation unit.
- void
- Gdb_index_info_reader::record_cu_ranges(Dwarf_die* die)
- {
- unsigned int shndx;
- unsigned int shndx2;
- off_t ranges_offset = die->ref_attribute(elfcpp::DW_AT_ranges, &shndx);
- if (ranges_offset != -1)
- {
- Dwarf_range_list* ranges = this->read_range_list(shndx, ranges_offset);
- if (ranges != NULL)
- this->gdb_index_->add_address_range_list(this->object(),
- this->cu_index_, ranges);
- return;
- }
- off_t low_pc = die->address_attribute(elfcpp::DW_AT_low_pc, &shndx);
- off_t high_pc = die->address_attribute(elfcpp::DW_AT_high_pc, &shndx2);
- if (high_pc == -1)
- {
- high_pc = die->uint_attribute(elfcpp::DW_AT_high_pc);
- high_pc += low_pc;
- shndx2 = shndx;
- }
- if ((low_pc != 0 || high_pc != 0) && low_pc != -1)
- {
- if (shndx != shndx2)
- {
- gold_warning(_("%s: DWARF info may be corrupt; low_pc and high_pc "
- "are in different sections"),
- this->object()->name().c_str());
- return;
- }
- if (shndx == 0 || this->object()->is_section_included(shndx))
- {
- Dwarf_range_list* ranges = new Dwarf_range_list();
- ranges->add(shndx, low_pc, high_pc);
- this->gdb_index_->add_address_range_list(this->object(),
- this->cu_index_, ranges);
- }
- }
- }
- // Read table and add the relevant names to the index. Returns true
- // if any names were added.
- bool
- Gdb_index_info_reader::read_pubtable(Dwarf_pubnames_table* table, off_t offset)
- {
- // If we couldn't read the section when building the cu_pubname_map,
- // then we won't find any pubnames now.
- if (table == NULL)
- return false;
- if (!table->read_header(offset))
- return false;
- while (true)
- {
- uint8_t flag_byte;
- const char* name = table->next_name(&flag_byte);
- if (name == NULL)
- break;
- this->gdb_index_->add_symbol(this->cu_index_, name, flag_byte);
- }
- return true;
- }
- // Read the .debug_pubnames and .debug_pubtypes tables for the CU or TU.
- // Returns TRUE if either a pubnames or pubtypes section was found.
- bool
- Gdb_index_info_reader::read_pubnames_and_pubtypes(Dwarf_die* die)
- {
- // If this is a skeleton debug-type die (generated via
- // -gsplit-dwarf), then the associated pubnames should have been
- // read along with the corresponding CU. In any case, there isn't
- // enough info inside to build a gdb index entry.
- if (die->tag() == elfcpp::DW_TAG_type_unit
- && die->string_attribute(elfcpp::DW_AT_GNU_dwo_name))
- return true;
- // We use stmt_list_off as a unique identifier for the
- // compilation unit and its associated type units.
- unsigned int shndx;
- off_t stmt_list_off = die->ref_attribute (elfcpp::DW_AT_stmt_list,
- &shndx);
- // Look for the attr as either a flag or a ref.
- off_t offset = die->ref_attribute(elfcpp::DW_AT_GNU_pubnames, &shndx);
- // Newer versions of GCC generate CUs, but not TUs, with
- // DW_AT_FORM_flag_present.
- unsigned int flag = die->uint_attribute(elfcpp::DW_AT_GNU_pubnames);
- if (offset == -1 && flag == 0)
- {
- // Didn't find the attribute.
- if (die->tag() == elfcpp::DW_TAG_type_unit)
- {
- // If die is a TU, then it might correspond to a CU which we
- // have read. If it does, then no need to read the pubnames.
- // If it doesn't, then the caller will have to parse the
- // dies manually to find the names.
- return this->gdb_index_->pubnames_read(this->object(),
- stmt_list_off);
- }
- else
- {
- // No attribute on the CU means that no pubnames were read.
- return false;
- }
- }
- // We found the attribute, so we can check if the corresponding
- // pubnames have been read.
- if (this->gdb_index_->pubnames_read(this->object(), stmt_list_off))
- return true;
- this->gdb_index_->set_pubnames_read(this->object(), stmt_list_off);
- // We have an attribute, and the pubnames haven't been read, so read
- // them.
- bool names = false;
- // In some of the cases, we could rely on the previous value of
- // offset here, but sorting out which cases complicates the logic
- // enough that it isn't worth it. So just look up the offset again.
- offset = this->gdb_index_->find_pubname_offset(this->cu_offset());
- names = this->read_pubtable(this->gdb_index_->pubnames_table(), offset);
- bool types = false;
- offset = this->gdb_index_->find_pubtype_offset(this->cu_offset());
- types = this->read_pubtable(this->gdb_index_->pubtypes_table(), offset);
- return names || types;
- }
- // Clear the declarations map.
- void
- Gdb_index_info_reader::clear_declarations()
- {
- // Free strings in memory we manage.
- for (Declaration_map::iterator it = this->declarations_.begin();
- it != this->declarations_.end();
- ++it)
- {
- if (it->second.parent_offset_ == -1)
- delete[] it->second.name_;
- }
- this->declarations_.clear();
- }
- // Print usage statistics.
- void
- Gdb_index_info_reader::print_stats()
- {
- fprintf(stderr, _("%s: DWARF CUs: %u\n"),
- program_name, Gdb_index_info_reader::dwarf_cu_count);
- fprintf(stderr, _("%s: DWARF CUs without pubnames/pubtypes: %u\n"),
- program_name, Gdb_index_info_reader::dwarf_cu_nopubnames_count);
- fprintf(stderr, _("%s: DWARF TUs: %u\n"),
- program_name, Gdb_index_info_reader::dwarf_tu_count);
- fprintf(stderr, _("%s: DWARF TUs without pubnames/pubtypes: %u\n"),
- program_name, Gdb_index_info_reader::dwarf_tu_nopubnames_count);
- }
- // Class Gdb_index.
- // Construct the .gdb_index section.
- Gdb_index::Gdb_index(Output_section* gdb_index_section)
- : Output_section_data(4),
- pubnames_table_(NULL),
- pubtypes_table_(NULL),
- gdb_index_section_(gdb_index_section),
- comp_units_(),
- type_units_(),
- ranges_(),
- cu_vector_list_(),
- cu_vector_offsets_(NULL),
- stringpool_(),
- tu_offset_(0),
- addr_offset_(0),
- symtab_offset_(0),
- cu_pool_offset_(0),
- stringpool_offset_(0),
- pubnames_object_(NULL),
- stmt_list_offset_(-1)
- {
- this->gdb_symtab_ = new Gdb_hashtab<Gdb_symbol>();
- }
- Gdb_index::~Gdb_index()
- {
- // Free the memory used by the symbol table.
- delete this->gdb_symtab_;
- // Free the memory used by the CU vectors.
- for (unsigned int i = 0; i < this->cu_vector_list_.size(); ++i)
- delete this->cu_vector_list_[i];
- }
- // Scan the pubnames and pubtypes sections and build a map of the
- // various cus and tus they refer to, so we can process the entries
- // when we encounter the die for that cu or tu.
- // Return the just-read table so it can be cached.
- Dwarf_pubnames_table*
- Gdb_index::map_pubtable_to_dies(unsigned int attr,
- Gdb_index_info_reader* dwinfo,
- Relobj* object,
- const unsigned char* symbols,
- off_t symbols_size)
- {
- uint64_t section_offset = 0;
- Dwarf_pubnames_table* table;
- Pubname_offset_map* map;
- if (attr == elfcpp::DW_AT_GNU_pubnames)
- {
- table = new Dwarf_pubnames_table(dwinfo, false);
- map = &this->cu_pubname_map_;
- }
- else
- {
- table = new Dwarf_pubnames_table(dwinfo, true);
- map = &this->cu_pubtype_map_;
- }
- map->clear();
- if (!table->read_section(object, symbols, symbols_size))
- return NULL;
- while (table->read_header(section_offset))
- {
- map->insert(std::make_pair(table->cu_offset(), section_offset));
- section_offset += table->subsection_size();
- }
- return table;
- }
- // Wrapper for map_pubtable_to_dies
- void
- Gdb_index::map_pubnames_and_types_to_dies(Gdb_index_info_reader* dwinfo,
- Relobj* object,
- const unsigned char* symbols,
- off_t symbols_size)
- {
- // This is a new object, so reset the relevant variables.
- this->pubnames_object_ = object;
- this->stmt_list_offset_ = -1;
- delete this->pubnames_table_;
- this->pubnames_table_
- = this->map_pubtable_to_dies(elfcpp::DW_AT_GNU_pubnames, dwinfo,
- object, symbols, symbols_size);
- delete this->pubtypes_table_;
- this->pubtypes_table_
- = this->map_pubtable_to_dies(elfcpp::DW_AT_GNU_pubtypes, dwinfo,
- object, symbols, symbols_size);
- }
- // Given a cu_offset, find the associated section of the pubnames
- // table.
- off_t
- Gdb_index::find_pubname_offset(off_t cu_offset)
- {
- Pubname_offset_map::iterator it = this->cu_pubname_map_.find(cu_offset);
- if (it != this->cu_pubname_map_.end())
- return it->second;
- return -1;
- }
- // Given a cu_offset, find the associated section of the pubnames
- // table.
- off_t
- Gdb_index::find_pubtype_offset(off_t cu_offset)
- {
- Pubname_offset_map::iterator it = this->cu_pubtype_map_.find(cu_offset);
- if (it != this->cu_pubtype_map_.end())
- return it->second;
- return -1;
- }
- // Scan a .debug_info or .debug_types input section.
- void
- Gdb_index::scan_debug_info(bool is_type_unit,
- Relobj* object,
- const unsigned char* symbols,
- off_t symbols_size,
- unsigned int shndx,
- unsigned int reloc_shndx,
- unsigned int reloc_type)
- {
- Gdb_index_info_reader dwinfo(is_type_unit, object,
- symbols, symbols_size,
- shndx, reloc_shndx,
- reloc_type, this);
- if (object != this->pubnames_object_)
- map_pubnames_and_types_to_dies(&dwinfo, object, symbols, symbols_size);
- dwinfo.parse();
- }
- // Add a symbol.
- void
- Gdb_index::add_symbol(int cu_index, const char* sym_name, uint8_t flags)
- {
- unsigned int hash = mapped_index_string_hash(
- reinterpret_cast<const unsigned char*>(sym_name));
- Gdb_symbol* sym = new Gdb_symbol();
- this->stringpool_.add(sym_name, true, &sym->name_key);
- sym->hashval = hash;
- sym->cu_vector_index = 0;
- Gdb_symbol* found = this->gdb_symtab_->add(sym);
- if (found == sym)
- {
- // New symbol -- allocate a new CU index vector.
- found->cu_vector_index = this->cu_vector_list_.size();
- this->cu_vector_list_.push_back(new Cu_vector());
- }
- else
- {
- // Found an existing symbol -- append to the existing
- // CU index vector.
- delete sym;
- }
- // Add the CU index to the vector list for this symbol,
- // if it's not already on the list. We only need to
- // check the last added entry.
- Cu_vector* cu_vec = this->cu_vector_list_[found->cu_vector_index];
- if (cu_vec->size() == 0
- || cu_vec->back().first != cu_index
- || cu_vec->back().second != flags)
- cu_vec->push_back(std::make_pair(cu_index, flags));
- }
- // Return TRUE if we have already processed the pubnames associated
- // with the statement list at the given OFFSET.
- bool
- Gdb_index::pubnames_read(const Relobj* object, off_t offset)
- {
- bool ret = (this->pubnames_object_ == object
- && this->stmt_list_offset_ == offset);
- return ret;
- }
- // Record that we have processed the pubnames associated with the
- // statement list for OBJECT at the given OFFSET.
- void
- Gdb_index::set_pubnames_read(const Relobj* object, off_t offset)
- {
- this->pubnames_object_ = object;
- this->stmt_list_offset_ = offset;
- }
- // Set the size of the .gdb_index section.
- void
- Gdb_index::set_final_data_size()
- {
- // Finalize the string pool.
- this->stringpool_.set_string_offsets();
- // Compute the total size of the CU vectors.
- // For each CU vector, include one entry for the count at the
- // beginning of the vector.
- unsigned int cu_vector_count = this->cu_vector_list_.size();
- unsigned int cu_vector_size = 0;
- this->cu_vector_offsets_ = new off_t[cu_vector_count];
- for (unsigned int i = 0; i < cu_vector_count; ++i)
- {
- Cu_vector* cu_vec = this->cu_vector_list_[i];
- cu_vector_offsets_[i] = cu_vector_size;
- cu_vector_size += gdb_index_offset_size * (cu_vec->size() + 1);
- }
- // Assign relative offsets to each portion of the index,
- // and find the total size of the section.
- section_size_type data_size = gdb_index_hdr_size;
- data_size += this->comp_units_.size() * gdb_index_cu_size;
- this->tu_offset_ = data_size;
- data_size += this->type_units_.size() * gdb_index_tu_size;
- this->addr_offset_ = data_size;
- for (unsigned int i = 0; i < this->ranges_.size(); ++i)
- data_size += this->ranges_[i].ranges->size() * gdb_index_addr_size;
- this->symtab_offset_ = data_size;
- data_size += this->gdb_symtab_->capacity() * gdb_index_sym_size;
- this->cu_pool_offset_ = data_size;
- data_size += cu_vector_size;
- this->stringpool_offset_ = data_size;
- data_size += this->stringpool_.get_strtab_size();
- this->set_data_size(data_size);
- }
- // Write the data to the file.
- void
- Gdb_index::do_write(Output_file* of)
- {
- const off_t off = this->offset();
- const off_t oview_size = this->data_size();
- unsigned char* const oview = of->get_output_view(off, oview_size);
- unsigned char* pov = oview;
- // Write the file header.
- // (1) Version number.
- elfcpp::Swap<32, false>::writeval(pov, gdb_index_version);
- pov += 4;
- // (2) Offset of the CU list.
- elfcpp::Swap<32, false>::writeval(pov, gdb_index_hdr_size);
- pov += 4;
- // (3) Offset of the types CU list.
- elfcpp::Swap<32, false>::writeval(pov, this->tu_offset_);
- pov += 4;
- // (4) Offset of the address area.
- elfcpp::Swap<32, false>::writeval(pov, this->addr_offset_);
- pov += 4;
- // (5) Offset of the symbol table.
- elfcpp::Swap<32, false>::writeval(pov, this->symtab_offset_);
- pov += 4;
- // (6) Offset of the constant pool.
- elfcpp::Swap<32, false>::writeval(pov, this->cu_pool_offset_);
- pov += 4;
- gold_assert(pov - oview == gdb_index_hdr_size);
- // Write the CU list.
- unsigned int comp_units_count = this->comp_units_.size();
- for (unsigned int i = 0; i < comp_units_count; ++i)
- {
- const Comp_unit& cu = this->comp_units_[i];
- elfcpp::Swap<64, false>::writeval(pov, cu.cu_offset);
- elfcpp::Swap<64, false>::writeval(pov + 8, cu.cu_length);
- pov += 16;
- }
- gold_assert(pov - oview == this->tu_offset_);
- // Write the types CU list.
- for (unsigned int i = 0; i < this->type_units_.size(); ++i)
- {
- const Type_unit& tu = this->type_units_[i];
- elfcpp::Swap<64, false>::writeval(pov, tu.tu_offset);
- elfcpp::Swap<64, false>::writeval(pov + 8, tu.type_offset);
- elfcpp::Swap<64, false>::writeval(pov + 16, tu.type_signature);
- pov += 24;
- }
- gold_assert(pov - oview == this->addr_offset_);
- // Write the address area.
- for (unsigned int i = 0; i < this->ranges_.size(); ++i)
- {
- int cu_index = this->ranges_[i].cu_index;
- // Translate negative indexes, which refer to a TU, to a
- // logical index into a concatenated CU/TU list.
- if (cu_index < 0)
- cu_index = comp_units_count + (-1 - cu_index);
- Relobj* object = this->ranges_[i].object;
- const Dwarf_range_list& ranges = *this->ranges_[i].ranges;
- for (unsigned int j = 0; j < ranges.size(); ++j)
- {
- const Dwarf_range_list::Range& range = ranges[j];
- uint64_t base = 0;
- if (range.shndx > 0)
- {
- const Output_section* os = object->output_section(range.shndx);
- base = (os->address()
- + object->output_section_offset(range.shndx));
- }
- elfcpp::Swap_aligned32<64, false>::writeval(pov, base + range.start);
- elfcpp::Swap_aligned32<64, false>::writeval(pov + 8,
- base + range.end);
- elfcpp::Swap<32, false>::writeval(pov + 16, cu_index);
- pov += 20;
- }
- }
- gold_assert(pov - oview == this->symtab_offset_);
- // Write the symbol table.
- for (unsigned int i = 0; i < this->gdb_symtab_->capacity(); ++i)
- {
- const Gdb_symbol* sym = (*this->gdb_symtab_)[i];
- section_offset_type name_offset = 0;
- unsigned int cu_vector_offset = 0;
- if (sym != NULL)
- {
- name_offset = (this->stringpool_.get_offset_from_key(sym->name_key)
- + this->stringpool_offset_ - this->cu_pool_offset_);
- cu_vector_offset = this->cu_vector_offsets_[sym->cu_vector_index];
- }
- elfcpp::Swap<32, false>::writeval(pov, name_offset);
- elfcpp::Swap<32, false>::writeval(pov + 4, cu_vector_offset);
- pov += 8;
- }
- gold_assert(pov - oview == this->cu_pool_offset_);
- // Write the CU vectors into the constant pool.
- for (unsigned int i = 0; i < this->cu_vector_list_.size(); ++i)
- {
- Cu_vector* cu_vec = this->cu_vector_list_[i];
- elfcpp::Swap<32, false>::writeval(pov, cu_vec->size());
- pov += 4;
- for (unsigned int j = 0; j < cu_vec->size(); ++j)
- {
- int cu_index = (*cu_vec)[j].first;
- uint8_t flags = (*cu_vec)[j].second;
- if (cu_index < 0)
- cu_index = comp_units_count + (-1 - cu_index);
- cu_index |= flags << 24;
- elfcpp::Swap<32, false>::writeval(pov, cu_index);
- pov += 4;
- }
- }
- gold_assert(pov - oview == this->stringpool_offset_);
- // Write the strings into the constant pool.
- this->stringpool_.write_to_buffer(pov, oview_size - this->stringpool_offset_);
- of->write_output_view(off, oview_size, oview);
- }
- // Print usage statistics.
- void
- Gdb_index::print_stats()
- {
- if (parameters->options().gdb_index())
- Gdb_index_info_reader::print_stats();
- }
- } // End namespace gold.
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