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Diffstat (limited to 'binutils-2.25/gold/script-sections.cc')
| -rw-r--r-- | binutils-2.25/gold/script-sections.cc | 4372 |
1 files changed, 4372 insertions, 0 deletions
diff --git a/binutils-2.25/gold/script-sections.cc b/binutils-2.25/gold/script-sections.cc new file mode 100644 index 00000000..a57e53ff --- /dev/null +++ b/binutils-2.25/gold/script-sections.cc @@ -0,0 +1,4372 @@ +// script-sections.cc -- linker script SECTIONS for gold + +// Copyright 2008, 2009, 2010, 2011 Free Software Foundation, Inc. +// Written by Ian Lance Taylor <iant@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 <cstring> +#include <algorithm> +#include <list> +#include <map> +#include <string> +#include <vector> +#include <fnmatch.h> + +#include "parameters.h" +#include "object.h" +#include "layout.h" +#include "output.h" +#include "script-c.h" +#include "script.h" +#include "script-sections.h" + +// Support for the SECTIONS clause in linker scripts. + +namespace gold +{ + +// A region of memory. +class Memory_region +{ + public: + Memory_region(const char* name, size_t namelen, unsigned int attributes, + Expression* start, Expression* length) + : name_(name, namelen), + attributes_(attributes), + start_(start), + length_(length), + current_offset_(0), + vma_sections_(), + lma_sections_(), + last_section_(NULL) + { } + + // Return the name of this region. + const std::string& + name() const + { return this->name_; } + + // Return the start address of this region. + Expression* + start_address() const + { return this->start_; } + + // Return the length of this region. + Expression* + length() const + { return this->length_; } + + // Print the region (when debugging). + void + print(FILE*) const; + + // Return true if <name,namelen> matches this region. + bool + name_match(const char* name, size_t namelen) + { + return (this->name_.length() == namelen + && strncmp(this->name_.c_str(), name, namelen) == 0); + } + + Expression* + get_current_address() const + { + return + script_exp_binary_add(this->start_, + script_exp_integer(this->current_offset_)); + } + + void + increment_offset(std::string section_name, uint64_t amount, + const Symbol_table* symtab, const Layout* layout) + { + this->current_offset_ += amount; + + if (this->current_offset_ + > this->length_->eval(symtab, layout, false)) + gold_error(_("section %s overflows end of region %s"), + section_name.c_str(), this->name_.c_str()); + } + + // Returns true iff there is room left in this region + // for AMOUNT more bytes of data. + bool + has_room_for(const Symbol_table* symtab, const Layout* layout, + uint64_t amount) const + { + return (this->current_offset_ + amount + < this->length_->eval(symtab, layout, false)); + } + + // Return true if the provided section flags + // are compatible with this region's attributes. + bool + attributes_compatible(elfcpp::Elf_Xword flags, elfcpp::Elf_Xword type) const; + + void + add_section(Output_section_definition* sec, bool vma) + { + if (vma) + this->vma_sections_.push_back(sec); + else + this->lma_sections_.push_back(sec); + } + + typedef std::vector<Output_section_definition*> Section_list; + + // Return the start of the list of sections + // whose VMAs are taken from this region. + Section_list::const_iterator + get_vma_section_list_start() const + { return this->vma_sections_.begin(); } + + // Return the start of the list of sections + // whose LMAs are taken from this region. + Section_list::const_iterator + get_lma_section_list_start() const + { return this->lma_sections_.begin(); } + + // Return the end of the list of sections + // whose VMAs are taken from this region. + Section_list::const_iterator + get_vma_section_list_end() const + { return this->vma_sections_.end(); } + + // Return the end of the list of sections + // whose LMAs are taken from this region. + Section_list::const_iterator + get_lma_section_list_end() const + { return this->lma_sections_.end(); } + + Output_section_definition* + get_last_section() const + { return this->last_section_; } + + void + set_last_section(Output_section_definition* sec) + { this->last_section_ = sec; } + + private: + + std::string name_; + unsigned int attributes_; + Expression* start_; + Expression* length_; + // The offset to the next free byte in the region. + // Note - for compatibility with GNU LD we only maintain one offset + // regardless of whether the region is being used for VMA values, + // LMA values, or both. + uint64_t current_offset_; + // A list of sections whose VMAs are set inside this region. + Section_list vma_sections_; + // A list of sections whose LMAs are set inside this region. + Section_list lma_sections_; + // The latest section to make use of this region. + Output_section_definition* last_section_; +}; + +// Return true if the provided section flags +// are compatible with this region's attributes. + +bool +Memory_region::attributes_compatible(elfcpp::Elf_Xword flags, + elfcpp::Elf_Xword type) const +{ + unsigned int attrs = this->attributes_; + + // No attributes means that this region is not compatible with anything. + if (attrs == 0) + return false; + + bool match = true; + do + { + switch (attrs & - attrs) + { + case MEM_EXECUTABLE: + if ((flags & elfcpp::SHF_EXECINSTR) == 0) + match = false; + break; + + case MEM_WRITEABLE: + if ((flags & elfcpp::SHF_WRITE) == 0) + match = false; + break; + + case MEM_READABLE: + // All sections are presumed readable. + break; + + case MEM_ALLOCATABLE: + if ((flags & elfcpp::SHF_ALLOC) == 0) + match = false; + break; + + case MEM_INITIALIZED: + if ((type & elfcpp::SHT_NOBITS) != 0) + match = false; + break; + } + attrs &= ~ (attrs & - attrs); + } + while (attrs != 0); + + return match; +} + +// Print a memory region. + +void +Memory_region::print(FILE* f) const +{ + fprintf(f, " %s", this->name_.c_str()); + + unsigned int attrs = this->attributes_; + if (attrs != 0) + { + fprintf(f, " ("); + do + { + switch (attrs & - attrs) + { + case MEM_EXECUTABLE: fputc('x', f); break; + case MEM_WRITEABLE: fputc('w', f); break; + case MEM_READABLE: fputc('r', f); break; + case MEM_ALLOCATABLE: fputc('a', f); break; + case MEM_INITIALIZED: fputc('i', f); break; + default: + gold_unreachable(); + } + attrs &= ~ (attrs & - attrs); + } + while (attrs != 0); + fputc(')', f); + } + + fprintf(f, " : origin = "); + this->start_->print(f); + fprintf(f, ", length = "); + this->length_->print(f); + fprintf(f, "\n"); +} + +// Manage orphan sections. This is intended to be largely compatible +// with the GNU linker. The Linux kernel implicitly relies on +// something similar to the GNU linker's orphan placement. We +// originally used a simpler scheme here, but it caused the kernel +// build to fail, and was also rather inefficient. + +class Orphan_section_placement +{ + private: + typedef Script_sections::Elements_iterator Elements_iterator; + + public: + Orphan_section_placement(); + + // Handle an output section during initialization of this mapping. + void + output_section_init(const std::string& name, Output_section*, + Elements_iterator location); + + // Initialize the last location. + void + last_init(Elements_iterator location); + + // Set *PWHERE to the address of an iterator pointing to the + // location to use for an orphan section. Return true if the + // iterator has a value, false otherwise. + bool + find_place(Output_section*, Elements_iterator** pwhere); + + // Return the iterator being used for sections at the very end of + // the linker script. + Elements_iterator + last_place() const; + + private: + // The places that we specifically recognize. This list is copied + // from the GNU linker. + enum Place_index + { + PLACE_TEXT, + PLACE_RODATA, + PLACE_DATA, + PLACE_TLS, + PLACE_TLS_BSS, + PLACE_BSS, + PLACE_REL, + PLACE_INTERP, + PLACE_NONALLOC, + PLACE_LAST, + PLACE_MAX + }; + + // The information we keep for a specific place. + struct Place + { + // The name of sections for this place. + const char* name; + // Whether we have a location for this place. + bool have_location; + // The iterator for this place. + Elements_iterator location; + }; + + // Initialize one place element. + void + initialize_place(Place_index, const char*); + + // The places. + Place places_[PLACE_MAX]; + // True if this is the first call to output_section_init. + bool first_init_; +}; + +// Initialize Orphan_section_placement. + +Orphan_section_placement::Orphan_section_placement() + : first_init_(true) +{ + this->initialize_place(PLACE_TEXT, ".text"); + this->initialize_place(PLACE_RODATA, ".rodata"); + this->initialize_place(PLACE_DATA, ".data"); + this->initialize_place(PLACE_TLS, NULL); + this->initialize_place(PLACE_TLS_BSS, NULL); + this->initialize_place(PLACE_BSS, ".bss"); + this->initialize_place(PLACE_REL, NULL); + this->initialize_place(PLACE_INTERP, ".interp"); + this->initialize_place(PLACE_NONALLOC, NULL); + this->initialize_place(PLACE_LAST, NULL); +} + +// Initialize one place element. + +void +Orphan_section_placement::initialize_place(Place_index index, const char* name) +{ + this->places_[index].name = name; + this->places_[index].have_location = false; +} + +// While initializing the Orphan_section_placement information, this +// is called once for each output section named in the linker script. +// If we found an output section during the link, it will be passed in +// OS. + +void +Orphan_section_placement::output_section_init(const std::string& name, + Output_section* os, + Elements_iterator location) +{ + bool first_init = this->first_init_; + this->first_init_ = false; + + for (int i = 0; i < PLACE_MAX; ++i) + { + if (this->places_[i].name != NULL && this->places_[i].name == name) + { + if (this->places_[i].have_location) + { + // We have already seen a section with this name. + return; + } + + this->places_[i].location = location; + this->places_[i].have_location = true; + + // If we just found the .bss section, restart the search for + // an unallocated section. This follows the GNU linker's + // behaviour. + if (i == PLACE_BSS) + this->places_[PLACE_NONALLOC].have_location = false; + + return; + } + } + + // Relocation sections. + if (!this->places_[PLACE_REL].have_location + && os != NULL + && (os->type() == elfcpp::SHT_REL || os->type() == elfcpp::SHT_RELA) + && (os->flags() & elfcpp::SHF_ALLOC) != 0) + { + this->places_[PLACE_REL].location = location; + this->places_[PLACE_REL].have_location = true; + } + + // We find the location for unallocated sections by finding the + // first debugging or comment section after the BSS section (if + // there is one). + if (!this->places_[PLACE_NONALLOC].have_location + && (name == ".comment" || Layout::is_debug_info_section(name.c_str()))) + { + // We add orphan sections after the location in PLACES_. We + // want to store unallocated sections before LOCATION. If this + // is the very first section, we can't use it. + if (!first_init) + { + --location; + this->places_[PLACE_NONALLOC].location = location; + this->places_[PLACE_NONALLOC].have_location = true; + } + } +} + +// Initialize the last location. + +void +Orphan_section_placement::last_init(Elements_iterator location) +{ + this->places_[PLACE_LAST].location = location; + this->places_[PLACE_LAST].have_location = true; +} + +// Set *PWHERE to the address of an iterator pointing to the location +// to use for an orphan section. Return true if the iterator has a +// value, false otherwise. + +bool +Orphan_section_placement::find_place(Output_section* os, + Elements_iterator** pwhere) +{ + // Figure out where OS should go. This is based on the GNU linker + // code. FIXME: The GNU linker handles small data sections + // specially, but we don't. + elfcpp::Elf_Word type = os->type(); + elfcpp::Elf_Xword flags = os->flags(); + Place_index index; + if ((flags & elfcpp::SHF_ALLOC) == 0 + && !Layout::is_debug_info_section(os->name())) + index = PLACE_NONALLOC; + else if ((flags & elfcpp::SHF_ALLOC) == 0) + index = PLACE_LAST; + else if (type == elfcpp::SHT_NOTE) + index = PLACE_INTERP; + else if ((flags & elfcpp::SHF_TLS) != 0) + { + if (type == elfcpp::SHT_NOBITS) + index = PLACE_TLS_BSS; + else + index = PLACE_TLS; + } + else if (type == elfcpp::SHT_NOBITS) + index = PLACE_BSS; + else if ((flags & elfcpp::SHF_WRITE) != 0) + index = PLACE_DATA; + else if (type == elfcpp::SHT_REL || type == elfcpp::SHT_RELA) + index = PLACE_REL; + else if ((flags & elfcpp::SHF_EXECINSTR) == 0) + index = PLACE_RODATA; + else + index = PLACE_TEXT; + + // If we don't have a location yet, try to find one based on a + // plausible ordering of sections. + if (!this->places_[index].have_location) + { + Place_index follow; + switch (index) + { + default: + follow = PLACE_MAX; + break; + case PLACE_RODATA: + follow = PLACE_TEXT; + break; + case PLACE_BSS: + follow = PLACE_DATA; + break; + case PLACE_REL: + follow = PLACE_TEXT; + break; + case PLACE_INTERP: + follow = PLACE_TEXT; + break; + case PLACE_TLS: + follow = PLACE_DATA; + break; + case PLACE_TLS_BSS: + follow = PLACE_TLS; + if (!this->places_[PLACE_TLS].have_location) + follow = PLACE_DATA; + break; + } + if (follow != PLACE_MAX && this->places_[follow].have_location) + { + // Set the location of INDEX to the location of FOLLOW. The + // location of INDEX will then be incremented by the caller, + // so anything in INDEX will continue to be after anything + // in FOLLOW. + this->places_[index].location = this->places_[follow].location; + this->places_[index].have_location = true; + } + } + + *pwhere = &this->places_[index].location; + bool ret = this->places_[index].have_location; + + // The caller will set the location. + this->places_[index].have_location = true; + + return ret; +} + +// Return the iterator being used for sections at the very end of the +// linker script. + +Orphan_section_placement::Elements_iterator +Orphan_section_placement::last_place() const +{ + gold_assert(this->places_[PLACE_LAST].have_location); + return this->places_[PLACE_LAST].location; +} + +// An element in a SECTIONS clause. + +class Sections_element +{ + public: + Sections_element() + { } + + virtual ~Sections_element() + { } + + // Return whether an output section is relro. + virtual bool + is_relro() const + { return false; } + + // Record that an output section is relro. + virtual void + set_is_relro() + { } + + // Create any required output sections. The only real + // implementation is in Output_section_definition. + virtual void + create_sections(Layout*) + { } + + // Add any symbol being defined to the symbol table. + virtual void + add_symbols_to_table(Symbol_table*) + { } + + // Finalize symbols and check assertions. + virtual void + finalize_symbols(Symbol_table*, const Layout*, uint64_t*) + { } + + // Return the output section name to use for an input file name and + // section name. This only real implementation is in + // Output_section_definition. + virtual const char* + output_section_name(const char*, const char*, Output_section***, + Script_sections::Section_type*, bool*) + { return NULL; } + + // Initialize OSP with an output section. + virtual void + orphan_section_init(Orphan_section_placement*, + Script_sections::Elements_iterator) + { } + + // Set section addresses. This includes applying assignments if the + // expression is an absolute value. + virtual void + set_section_addresses(Symbol_table*, Layout*, uint64_t*, uint64_t*, + uint64_t*) + { } + + // Check a constraint (ONLY_IF_RO, etc.) on an output section. If + // this section is constrained, and the input sections do not match, + // return the constraint, and set *POSD. + virtual Section_constraint + check_constraint(Output_section_definition**) + { return CONSTRAINT_NONE; } + + // See if this is the alternate output section for a constrained + // output section. If it is, transfer the Output_section and return + // true. Otherwise return false. + virtual bool + alternate_constraint(Output_section_definition*, Section_constraint) + { return false; } + + // Get the list of segments to use for an allocated section when + // using a PHDRS clause. If this is an allocated section, return + // the Output_section, and set *PHDRS_LIST (the first parameter) to + // the list of PHDRS to which it should be attached. If the PHDRS + // were not specified, don't change *PHDRS_LIST. When not returning + // NULL, set *ORPHAN (the second parameter) according to whether + // this is an orphan section--one that is not mentioned in the + // linker script. + virtual Output_section* + allocate_to_segment(String_list**, bool*) + { return NULL; } + + // Look for an output section by name and return the address, the + // load address, the alignment, and the size. This is used when an + // expression refers to an output section which was not actually + // created. This returns true if the section was found, false + // otherwise. The only real definition is for + // Output_section_definition. + virtual bool + get_output_section_info(const char*, uint64_t*, uint64_t*, uint64_t*, + uint64_t*) const + { return false; } + + // Return the associated Output_section if there is one. + virtual Output_section* + get_output_section() const + { return NULL; } + + // Set the section's memory regions. + virtual void + set_memory_region(Memory_region*, bool) + { gold_error(_("Attempt to set a memory region for a non-output section")); } + + // Print the element for debugging purposes. + virtual void + print(FILE* f) const = 0; +}; + +// An assignment in a SECTIONS clause outside of an output section. + +class Sections_element_assignment : public Sections_element +{ + public: + Sections_element_assignment(const char* name, size_t namelen, + Expression* val, bool provide, bool hidden) + : assignment_(name, namelen, false, val, provide, hidden) + { } + + // Add the symbol to the symbol table. + void + add_symbols_to_table(Symbol_table* symtab) + { this->assignment_.add_to_table(symtab); } + + // Finalize the symbol. + void + finalize_symbols(Symbol_table* symtab, const Layout* layout, + uint64_t* dot_value) + { + this->assignment_.finalize_with_dot(symtab, layout, *dot_value, NULL); + } + + // Set the section address. There is no section here, but if the + // value is absolute, we set the symbol. This permits us to use + // absolute symbols when setting dot. + void + set_section_addresses(Symbol_table* symtab, Layout* layout, + uint64_t* dot_value, uint64_t*, uint64_t*) + { + this->assignment_.set_if_absolute(symtab, layout, true, *dot_value, NULL); + } + + // Print for debugging. + void + print(FILE* f) const + { + fprintf(f, " "); + this->assignment_.print(f); + } + + private: + Symbol_assignment assignment_; +}; + +// An assignment to the dot symbol in a SECTIONS clause outside of an +// output section. + +class Sections_element_dot_assignment : public Sections_element +{ + public: + Sections_element_dot_assignment(Expression* val) + : val_(val) + { } + + // Finalize the symbol. + void + finalize_symbols(Symbol_table* symtab, const Layout* layout, + uint64_t* dot_value) + { + // We ignore the section of the result because outside of an + // output section definition the dot symbol is always considered + // to be absolute. + *dot_value = this->val_->eval_with_dot(symtab, layout, true, *dot_value, + NULL, NULL, NULL, false); + } + + // Update the dot symbol while setting section addresses. + void + set_section_addresses(Symbol_table* symtab, Layout* layout, + uint64_t* dot_value, uint64_t* dot_alignment, + uint64_t* load_address) + { + *dot_value = this->val_->eval_with_dot(symtab, layout, false, *dot_value, + NULL, NULL, dot_alignment, false); + *load_address = *dot_value; + } + + // Print for debugging. + void + print(FILE* f) const + { + fprintf(f, " . = "); + this->val_->print(f); + fprintf(f, "\n"); + } + + private: + Expression* val_; +}; + +// An assertion in a SECTIONS clause outside of an output section. + +class Sections_element_assertion : public Sections_element +{ + public: + Sections_element_assertion(Expression* check, const char* message, + size_t messagelen) + : assertion_(check, message, messagelen) + { } + + // Check the assertion. + void + finalize_symbols(Symbol_table* symtab, const Layout* layout, uint64_t*) + { this->assertion_.check(symtab, layout); } + + // Print for debugging. + void + print(FILE* f) const + { + fprintf(f, " "); + this->assertion_.print(f); + } + + private: + Script_assertion assertion_; +}; + +// An element in an output section in a SECTIONS clause. + +class Output_section_element +{ + public: + // A list of input sections. + typedef std::list<Output_section::Input_section> Input_section_list; + + Output_section_element() + { } + + virtual ~Output_section_element() + { } + + // Return whether this element requires an output section to exist. + virtual bool + needs_output_section() const + { return false; } + + // Add any symbol being defined to the symbol table. + virtual void + add_symbols_to_table(Symbol_table*) + { } + + // Finalize symbols and check assertions. + virtual void + finalize_symbols(Symbol_table*, const Layout*, uint64_t*, Output_section**) + { } + + // Return whether this element matches FILE_NAME and SECTION_NAME. + // The only real implementation is in Output_section_element_input. + virtual bool + match_name(const char*, const char*, bool *) const + { return false; } + + // Set section addresses. This includes applying assignments if the + // expression is an absolute value. + virtual void + set_section_addresses(Symbol_table*, Layout*, Output_section*, uint64_t, + uint64_t*, uint64_t*, Output_section**, std::string*, + Input_section_list*) + { } + + // Print the element for debugging purposes. + virtual void + print(FILE* f) const = 0; + + protected: + // Return a fill string that is LENGTH bytes long, filling it with + // FILL. + std::string + get_fill_string(const std::string* fill, section_size_type length) const; +}; + +std::string +Output_section_element::get_fill_string(const std::string* fill, + section_size_type length) const +{ + std::string this_fill; + this_fill.reserve(length); + while (this_fill.length() + fill->length() <= length) + this_fill += *fill; + if (this_fill.length() < length) + this_fill.append(*fill, 0, length - this_fill.length()); + return this_fill; +} + +// A symbol assignment in an output section. + +class Output_section_element_assignment : public Output_section_element +{ + public: + Output_section_element_assignment(const char* name, size_t namelen, + Expression* val, bool provide, + bool hidden) + : assignment_(name, namelen, false, val, provide, hidden) + { } + + // Add the symbol to the symbol table. + void + add_symbols_to_table(Symbol_table* symtab) + { this->assignment_.add_to_table(symtab); } + + // Finalize the symbol. + void + finalize_symbols(Symbol_table* symtab, const Layout* layout, + uint64_t* dot_value, Output_section** dot_section) + { + this->assignment_.finalize_with_dot(symtab, layout, *dot_value, + *dot_section); + } + + // Set the section address. There is no section here, but if the + // value is absolute, we set the symbol. This permits us to use + // absolute symbols when setting dot. + void + set_section_addresses(Symbol_table* symtab, Layout* layout, Output_section*, + uint64_t, uint64_t* dot_value, uint64_t*, + Output_section** dot_section, std::string*, + Input_section_list*) + { + this->assignment_.set_if_absolute(symtab, layout, true, *dot_value, + *dot_section); + } + + // Print for debugging. + void + print(FILE* f) const + { + fprintf(f, " "); + this->assignment_.print(f); + } + + private: + Symbol_assignment assignment_; +}; + +// An assignment to the dot symbol in an output section. + +class Output_section_element_dot_assignment : public Output_section_element +{ + public: + Output_section_element_dot_assignment(Expression* val) + : val_(val) + { } + + // An assignment to dot within an output section is enough to force + // the output section to exist. + bool + needs_output_section() const + { return true; } + + // Finalize the symbol. + void + finalize_symbols(Symbol_table* symtab, const Layout* layout, + uint64_t* dot_value, Output_section** dot_section) + { + *dot_value = this->val_->eval_with_dot(symtab, layout, true, *dot_value, + *dot_section, dot_section, NULL, + true); + } + + // Update the dot symbol while setting section addresses. + void + set_section_addresses(Symbol_table* symtab, Layout* layout, Output_section*, + uint64_t, uint64_t* dot_value, uint64_t*, + Output_section** dot_section, std::string*, + Input_section_list*); + + // Print for debugging. + void + print(FILE* f) const + { + fprintf(f, " . = "); + this->val_->print(f); + fprintf(f, "\n"); + } + + private: + Expression* val_; +}; + +// Update the dot symbol while setting section addresses. + +void +Output_section_element_dot_assignment::set_section_addresses( + Symbol_table* symtab, + Layout* layout, + Output_section* output_section, + uint64_t, + uint64_t* dot_value, + uint64_t* dot_alignment, + Output_section** dot_section, + std::string* fill, + Input_section_list*) +{ + uint64_t next_dot = this->val_->eval_with_dot(symtab, layout, false, + *dot_value, *dot_section, + dot_section, dot_alignment, + true); + if (next_dot < *dot_value) + gold_error(_("dot may not move backward")); + if (next_dot > *dot_value && output_section != NULL) + { + section_size_type length = convert_to_section_size_type(next_dot + - *dot_value); + Output_section_data* posd; + if (fill->empty()) + posd = new Output_data_zero_fill(length, 0); + else + { + std::string this_fill = this->get_fill_string(fill, length); + posd = new Output_data_const(this_fill, 0); + } + output_section->add_output_section_data(posd); + layout->new_output_section_data_from_script(posd); + } + *dot_value = next_dot; +} + +// An assertion in an output section. + +class Output_section_element_assertion : public Output_section_element +{ + public: + Output_section_element_assertion(Expression* check, const char* message, + size_t messagelen) + : assertion_(check, message, messagelen) + { } + + void + print(FILE* f) const + { + fprintf(f, " "); + this->assertion_.print(f); + } + + private: + Script_assertion assertion_; +}; + +// We use a special instance of Output_section_data to handle BYTE, +// SHORT, etc. This permits forward references to symbols in the +// expressions. + +class Output_data_expression : public Output_section_data +{ + public: + Output_data_expression(int size, bool is_signed, Expression* val, + const Symbol_table* symtab, const Layout* layout, + uint64_t dot_value, Output_section* dot_section) + : Output_section_data(size, 0, true), + is_signed_(is_signed), val_(val), symtab_(symtab), + layout_(layout), dot_value_(dot_value), dot_section_(dot_section) + { } + + protected: + // Write the data to the output file. + void + do_write(Output_file*); + + // Write the data to a buffer. + void + do_write_to_buffer(unsigned char*); + + // Write to a map file. + void + do_print_to_mapfile(Mapfile* mapfile) const + { mapfile->print_output_data(this, _("** expression")); } + + private: + template<bool big_endian> + void + endian_write_to_buffer(uint64_t, unsigned char*); + + bool is_signed_; + Expression* val_; + const Symbol_table* symtab_; + const Layout* layout_; + uint64_t dot_value_; + Output_section* dot_section_; +}; + +// Write the data element to the output file. + +void +Output_data_expression::do_write(Output_file* of) +{ + unsigned char* view = of->get_output_view(this->offset(), this->data_size()); + this->write_to_buffer(view); + of->write_output_view(this->offset(), this->data_size(), view); +} + +// Write the data element to a buffer. + +void +Output_data_expression::do_write_to_buffer(unsigned char* buf) +{ + uint64_t val = this->val_->eval_with_dot(this->symtab_, this->layout_, + true, this->dot_value_, + this->dot_section_, NULL, NULL, + false); + + if (parameters->target().is_big_endian()) + this->endian_write_to_buffer<true>(val, buf); + else + this->endian_write_to_buffer<false>(val, buf); +} + +template<bool big_endian> +void +Output_data_expression::endian_write_to_buffer(uint64_t val, + unsigned char* buf) +{ + switch (this->data_size()) + { + case 1: + elfcpp::Swap_unaligned<8, big_endian>::writeval(buf, val); + break; + case 2: + elfcpp::Swap_unaligned<16, big_endian>::writeval(buf, val); + break; + case 4: + elfcpp::Swap_unaligned<32, big_endian>::writeval(buf, val); + break; + case 8: + if (parameters->target().get_size() == 32) + { + val &= 0xffffffff; + if (this->is_signed_ && (val & 0x80000000) != 0) + val |= 0xffffffff00000000LL; + } + elfcpp::Swap_unaligned<64, big_endian>::writeval(buf, val); + break; + default: + gold_unreachable(); + } +} + +// A data item in an output section. + +class Output_section_element_data : public Output_section_element +{ + public: + Output_section_element_data(int size, bool is_signed, Expression* val) + : size_(size), is_signed_(is_signed), val_(val) + { } + + // If there is a data item, then we must create an output section. + bool + needs_output_section() const + { return true; } + + // Finalize symbols--we just need to update dot. + void + finalize_symbols(Symbol_table*, const Layout*, uint64_t* dot_value, + Output_section**) + { *dot_value += this->size_; } + + // Store the value in the section. + void + set_section_addresses(Symbol_table*, Layout*, Output_section*, uint64_t, + uint64_t* dot_value, uint64_t*, Output_section**, + std::string*, Input_section_list*); + + // Print for debugging. + void + print(FILE*) const; + + private: + // The size in bytes. + int size_; + // Whether the value is signed. + bool is_signed_; + // The value. + Expression* val_; +}; + +// Store the value in the section. + +void +Output_section_element_data::set_section_addresses( + Symbol_table* symtab, + Layout* layout, + Output_section* os, + uint64_t, + uint64_t* dot_value, + uint64_t*, + Output_section** dot_section, + std::string*, + Input_section_list*) +{ + gold_assert(os != NULL); + Output_data_expression* expression = + new Output_data_expression(this->size_, this->is_signed_, this->val_, + symtab, layout, *dot_value, *dot_section); + os->add_output_section_data(expression); + layout->new_output_section_data_from_script(expression); + *dot_value += this->size_; +} + +// Print for debugging. + +void +Output_section_element_data::print(FILE* f) const +{ + const char* s; + switch (this->size_) + { + case 1: + s = "BYTE"; + break; + case 2: + s = "SHORT"; + break; + case 4: + s = "LONG"; + break; + case 8: + if (this->is_signed_) + s = "SQUAD"; + else + s = "QUAD"; + break; + default: + gold_unreachable(); + } + fprintf(f, " %s(", s); + this->val_->print(f); + fprintf(f, ")\n"); +} + +// A fill value setting in an output section. + +class Output_section_element_fill : public Output_section_element +{ + public: + Output_section_element_fill(Expression* val) + : val_(val) + { } + + // Update the fill value while setting section addresses. + void + set_section_addresses(Symbol_table* symtab, Layout* layout, Output_section*, + uint64_t, uint64_t* dot_value, uint64_t*, + Output_section** dot_section, + std::string* fill, Input_section_list*) + { + Output_section* fill_section; + uint64_t fill_val = this->val_->eval_with_dot(symtab, layout, false, + *dot_value, *dot_section, + &fill_section, NULL, false); + if (fill_section != NULL) + gold_warning(_("fill value is not absolute")); + // FIXME: The GNU linker supports fill values of arbitrary length. + unsigned char fill_buff[4]; + elfcpp::Swap_unaligned<32, true>::writeval(fill_buff, fill_val); + fill->assign(reinterpret_cast<char*>(fill_buff), 4); + } + + // Print for debugging. + void + print(FILE* f) const + { + fprintf(f, " FILL("); + this->val_->print(f); + fprintf(f, ")\n"); + } + + private: + // The new fill value. + Expression* val_; +}; + +// An input section specification in an output section + +class Output_section_element_input : public Output_section_element +{ + public: + Output_section_element_input(const Input_section_spec* spec, bool keep); + + // Finalize symbols--just update the value of the dot symbol. + void + finalize_symbols(Symbol_table*, const Layout*, uint64_t* dot_value, + Output_section** dot_section) + { + *dot_value = this->final_dot_value_; + *dot_section = this->final_dot_section_; + } + + // See whether we match FILE_NAME and SECTION_NAME as an input section. + // If we do then also indicate whether the section should be KEPT. + bool + match_name(const char* file_name, const char* section_name, bool* keep) const; + + // Set the section address. + void + set_section_addresses(Symbol_table* symtab, Layout* layout, Output_section*, + uint64_t subalign, uint64_t* dot_value, uint64_t*, + Output_section**, std::string* fill, + Input_section_list*); + + // Print for debugging. + void + print(FILE* f) const; + + private: + // An input section pattern. + struct Input_section_pattern + { + std::string pattern; + bool pattern_is_wildcard; + Sort_wildcard sort; + + Input_section_pattern(const char* patterna, size_t patternlena, + Sort_wildcard sorta) + : pattern(patterna, patternlena), + pattern_is_wildcard(is_wildcard_string(this->pattern.c_str())), + sort(sorta) + { } + }; + + typedef std::vector<Input_section_pattern> Input_section_patterns; + + // Filename_exclusions is a pair of filename pattern and a bool + // indicating whether the filename is a wildcard. + typedef std::vector<std::pair<std::string, bool> > Filename_exclusions; + + // Return whether STRING matches PATTERN, where IS_WILDCARD_PATTERN + // indicates whether this is a wildcard pattern. + static inline bool + match(const char* string, const char* pattern, bool is_wildcard_pattern) + { + return (is_wildcard_pattern + ? fnmatch(pattern, string, 0) == 0 + : strcmp(string, pattern) == 0); + } + + // See if we match a file name. + bool + match_file_name(const char* file_name) const; + + // The file name pattern. If this is the empty string, we match all + // files. + std::string filename_pattern_; + // Whether the file name pattern is a wildcard. + bool filename_is_wildcard_; + // How the file names should be sorted. This may only be + // SORT_WILDCARD_NONE or SORT_WILDCARD_BY_NAME. + Sort_wildcard filename_sort_; + // The list of file names to exclude. + Filename_exclusions filename_exclusions_; + // The list of input section patterns. + Input_section_patterns input_section_patterns_; + // Whether to keep this section when garbage collecting. + bool keep_; + // The value of dot after including all matching sections. + uint64_t final_dot_value_; + // The section where dot is defined after including all matching + // sections. + Output_section* final_dot_section_; +}; + +// Construct Output_section_element_input. The parser records strings +// as pointers into a copy of the script file, which will go away when +// parsing is complete. We make sure they are in std::string objects. + +Output_section_element_input::Output_section_element_input( + const Input_section_spec* spec, + bool keep) + : filename_pattern_(), + filename_is_wildcard_(false), + filename_sort_(spec->file.sort), + filename_exclusions_(), + input_section_patterns_(), + keep_(keep), + final_dot_value_(0), + final_dot_section_(NULL) +{ + // The filename pattern "*" is common, and matches all files. Turn + // it into the empty string. + if (spec->file.name.length != 1 || spec->file.name.value[0] != '*') + this->filename_pattern_.assign(spec->file.name.value, + spec->file.name.length); + this->filename_is_wildcard_ = is_wildcard_string(this->filename_pattern_.c_str()); + + if (spec->input_sections.exclude != NULL) + { + for (String_list::const_iterator p = + spec->input_sections.exclude->begin(); + p != spec->input_sections.exclude->end(); + ++p) + { + bool is_wildcard = is_wildcard_string((*p).c_str()); + this->filename_exclusions_.push_back(std::make_pair(*p, + is_wildcard)); + } + } + + if (spec->input_sections.sections != NULL) + { + Input_section_patterns& isp(this->input_section_patterns_); + for (String_sort_list::const_iterator p = + spec->input_sections.sections->begin(); + p != spec->input_sections.sections->end(); + ++p) + isp.push_back(Input_section_pattern(p->name.value, p->name.length, + p->sort)); + } +} + +// See whether we match FILE_NAME. + +bool +Output_section_element_input::match_file_name(const char* file_name) const +{ + if (!this->filename_pattern_.empty()) + { + // If we were called with no filename, we refuse to match a + // pattern which requires a file name. + if (file_name == NULL) + return false; + + if (!match(file_name, this->filename_pattern_.c_str(), + this->filename_is_wildcard_)) + return false; + } + + if (file_name != NULL) + { + // Now we have to see whether FILE_NAME matches one of the + // exclusion patterns, if any. + for (Filename_exclusions::const_iterator p = + this->filename_exclusions_.begin(); + p != this->filename_exclusions_.end(); + ++p) + { + if (match(file_name, p->first.c_str(), p->second)) + return false; + } + } + + return true; +} + +// See whether we match FILE_NAME and SECTION_NAME. If we do then +// KEEP indicates whether the section should survive garbage collection. + +bool +Output_section_element_input::match_name(const char* file_name, + const char* section_name, + bool *keep) const +{ + if (!this->match_file_name(file_name)) + return false; + + *keep = this->keep_; + + // If there are no section name patterns, then we match. + if (this->input_section_patterns_.empty()) + return true; + + // See whether we match the section name patterns. + for (Input_section_patterns::const_iterator p = + this->input_section_patterns_.begin(); + p != this->input_section_patterns_.end(); + ++p) + { + if (match(section_name, p->pattern.c_str(), p->pattern_is_wildcard)) + return true; + } + + // We didn't match any section names, so we didn't match. + return false; +} + +// Information we use to sort the input sections. + +class Input_section_info +{ + public: + Input_section_info(const Output_section::Input_section& input_section) + : input_section_(input_section), section_name_(), + size_(0), addralign_(1) + { } + + // Return the simple input section. + const Output_section::Input_section& + input_section() const + { return this->input_section_; } + + // Return the object. + Relobj* + relobj() const + { return this->input_section_.relobj(); } + + // Return the section index. + unsigned int + shndx() + { return this->input_section_.shndx(); } + + // Return the section name. + const std::string& + section_name() const + { return this->section_name_; } + + // Set the section name. + void + set_section_name(const std::string name) + { this->section_name_ = name; } + + // Return the section size. + uint64_t + size() const + { return this->size_; } + + // Set the section size. + void + set_size(uint64_t size) + { this->size_ = size; } + + // Return the address alignment. + uint64_t + addralign() const + { return this->addralign_; } + + // Set the address alignment. + void + set_addralign(uint64_t addralign) + { this->addralign_ = addralign; } + + private: + // Input section, can be a relaxed section. + Output_section::Input_section input_section_; + // Name of the section. + std::string section_name_; + // Section size. + uint64_t size_; + // Address alignment. + uint64_t addralign_; +}; + +// A class to sort the input sections. + +class Input_section_sorter +{ + public: + Input_section_sorter(Sort_wildcard filename_sort, Sort_wildcard section_sort) + : filename_sort_(filename_sort), section_sort_(section_sort) + { } + + bool + operator()(const Input_section_info&, const Input_section_info&) const; + + private: + Sort_wildcard filename_sort_; + Sort_wildcard section_sort_; +}; + +bool +Input_section_sorter::operator()(const Input_section_info& isi1, + const Input_section_info& isi2) const +{ + if (this->section_sort_ == SORT_WILDCARD_BY_NAME + || this->section_sort_ == SORT_WILDCARD_BY_NAME_BY_ALIGNMENT + || (this->section_sort_ == SORT_WILDCARD_BY_ALIGNMENT_BY_NAME + && isi1.addralign() == isi2.addralign())) + { + if (isi1.section_name() != isi2.section_name()) + return isi1.section_name() < isi2.section_name(); + } + if (this->section_sort_ == SORT_WILDCARD_BY_ALIGNMENT + || this->section_sort_ == SORT_WILDCARD_BY_NAME_BY_ALIGNMENT + || this->section_sort_ == SORT_WILDCARD_BY_ALIGNMENT_BY_NAME) + { + if (isi1.addralign() != isi2.addralign()) + return isi1.addralign() < isi2.addralign(); + } + if (this->filename_sort_ == SORT_WILDCARD_BY_NAME) + { + if (isi1.relobj()->name() != isi2.relobj()->name()) + return (isi1.relobj()->name() < isi2.relobj()->name()); + } + + // Otherwise we leave them in the same order. + return false; +} + +// Set the section address. Look in INPUT_SECTIONS for sections which +// match this spec, sort them as specified, and add them to the output +// section. + +void +Output_section_element_input::set_section_addresses( + Symbol_table*, + Layout* layout, + Output_section* output_section, + uint64_t subalign, + uint64_t* dot_value, + uint64_t*, + Output_section** dot_section, + std::string* fill, + Input_section_list* input_sections) +{ + // We build a list of sections which match each + // Input_section_pattern. + + typedef std::vector<std::vector<Input_section_info> > Matching_sections; + size_t input_pattern_count = this->input_section_patterns_.size(); + if (input_pattern_count == 0) + input_pattern_count = 1; + Matching_sections matching_sections(input_pattern_count); + + // Look through the list of sections for this output section. Add + // each one which matches to one of the elements of + // MATCHING_SECTIONS. + + Input_section_list::iterator p = input_sections->begin(); + while (p != input_sections->end()) + { + Relobj* relobj = p->relobj(); + unsigned int shndx = p->shndx(); + Input_section_info isi(*p); + + // Calling section_name and section_addralign is not very + // efficient. + + // Lock the object so that we can get information about the + // section. This is OK since we know we are single-threaded + // here. + { + const Task* task = reinterpret_cast<const Task*>(-1); + Task_lock_obj<Object> tl(task, relobj); + + isi.set_section_name(relobj->section_name(shndx)); + if (p->is_relaxed_input_section()) + { + // We use current data size because relaxed section sizes may not + // have finalized yet. + isi.set_size(p->relaxed_input_section()->current_data_size()); + isi.set_addralign(p->relaxed_input_section()->addralign()); + } + else + { + isi.set_size(relobj->section_size(shndx)); + isi.set_addralign(relobj->section_addralign(shndx)); + } + } + + if (!this->match_file_name(relobj->name().c_str())) + ++p; + else if (this->input_section_patterns_.empty()) + { + matching_sections[0].push_back(isi); + p = input_sections->erase(p); + } + else + { + size_t i; + for (i = 0; i < input_pattern_count; ++i) + { + const Input_section_pattern& + isp(this->input_section_patterns_[i]); + if (match(isi.section_name().c_str(), isp.pattern.c_str(), + isp.pattern_is_wildcard)) + break; + } + + if (i >= this->input_section_patterns_.size()) + ++p; + else + { + matching_sections[i].push_back(isi); + p = input_sections->erase(p); + } + } + } + + // Look through MATCHING_SECTIONS. Sort each one as specified, + // using a stable sort so that we get the default order when + // sections are otherwise equal. Add each input section to the + // output section. + + uint64_t dot = *dot_value; + for (size_t i = 0; i < input_pattern_count; ++i) + { + if (matching_sections[i].empty()) + continue; + + gold_assert(output_section != NULL); + + const Input_section_pattern& isp(this->input_section_patterns_[i]); + if (isp.sort != SORT_WILDCARD_NONE + || this->filename_sort_ != SORT_WILDCARD_NONE) + std::stable_sort(matching_sections[i].begin(), + matching_sections[i].end(), + Input_section_sorter(this->filename_sort_, + isp.sort)); + + for (std::vector<Input_section_info>::const_iterator p = + matching_sections[i].begin(); + p != matching_sections[i].end(); + ++p) + { + // Override the original address alignment if SUBALIGN is specified + // and is greater than the original alignment. We need to make a + // copy of the input section to modify the alignment. + Output_section::Input_section sis(p->input_section()); + + uint64_t this_subalign = sis.addralign(); + if (!sis.is_input_section()) + sis.output_section_data()->finalize_data_size(); + uint64_t data_size = sis.data_size(); + if (this_subalign < subalign) + { + this_subalign = subalign; + sis.set_addralign(subalign); + } + + uint64_t address = align_address(dot, this_subalign); + + if (address > dot && !fill->empty()) + { + section_size_type length = + convert_to_section_size_type(address - dot); + std::string this_fill = this->get_fill_string(fill, length); + Output_section_data* posd = new Output_data_const(this_fill, 0); + output_section->add_output_section_data(posd); + layout->new_output_section_data_from_script(posd); + } + + output_section->add_script_input_section(sis); + dot = address + data_size; + } + } + + // An SHF_TLS/SHT_NOBITS section does not take up any + // address space. + if (output_section == NULL + || (output_section->flags() & elfcpp::SHF_TLS) == 0 + || output_section->type() != elfcpp::SHT_NOBITS) + *dot_value = dot; + + this->final_dot_value_ = *dot_value; + this->final_dot_section_ = *dot_section; +} + +// Print for debugging. + +void +Output_section_element_input::print(FILE* f) const +{ + fprintf(f, " "); + + if (this->keep_) + fprintf(f, "KEEP("); + + if (!this->filename_pattern_.empty()) + { + bool need_close_paren = false; + switch (this->filename_sort_) + { + case SORT_WILDCARD_NONE: + break; + case SORT_WILDCARD_BY_NAME: + fprintf(f, "SORT_BY_NAME("); + need_close_paren = true; + break; + default: + gold_unreachable(); + } + + fprintf(f, "%s", this->filename_pattern_.c_str()); + + if (need_close_paren) + fprintf(f, ")"); + } + + if (!this->input_section_patterns_.empty() + || !this->filename_exclusions_.empty()) + { + fprintf(f, "("); + + bool need_space = false; + if (!this->filename_exclusions_.empty()) + { + fprintf(f, "EXCLUDE_FILE("); + bool need_comma = false; + for (Filename_exclusions::const_iterator p = + this->filename_exclusions_.begin(); + p != this->filename_exclusions_.end(); + ++p) + { + if (need_comma) + fprintf(f, ", "); + fprintf(f, "%s", p->first.c_str()); + need_comma = true; + } + fprintf(f, ")"); + need_space = true; + } + + for (Input_section_patterns::const_iterator p = + this->input_section_patterns_.begin(); + p != this->input_section_patterns_.end(); + ++p) + { + if (need_space) + fprintf(f, " "); + + int close_parens = 0; + switch (p->sort) + { + case SORT_WILDCARD_NONE: + break; + case SORT_WILDCARD_BY_NAME: + fprintf(f, "SORT_BY_NAME("); + close_parens = 1; + break; + case SORT_WILDCARD_BY_ALIGNMENT: + fprintf(f, "SORT_BY_ALIGNMENT("); + close_parens = 1; + break; + case SORT_WILDCARD_BY_NAME_BY_ALIGNMENT: + fprintf(f, "SORT_BY_NAME(SORT_BY_ALIGNMENT("); + close_parens = 2; + break; + case SORT_WILDCARD_BY_ALIGNMENT_BY_NAME: + fprintf(f, "SORT_BY_ALIGNMENT(SORT_BY_NAME("); + close_parens = 2; + break; + default: + gold_unreachable(); + } + + fprintf(f, "%s", p->pattern.c_str()); + + for (int i = 0; i < close_parens; ++i) + fprintf(f, ")"); + + need_space = true; + } + + fprintf(f, ")"); + } + + if (this->keep_) + fprintf(f, ")"); + + fprintf(f, "\n"); +} + +// An output section. + +class Output_section_definition : public Sections_element +{ + public: + typedef Output_section_element::Input_section_list Input_section_list; + + Output_section_definition(const char* name, size_t namelen, + const Parser_output_section_header* header); + + // Finish the output section with the information in the trailer. + void + finish(const Parser_output_section_trailer* trailer); + + // Add a symbol to be defined. + void + add_symbol_assignment(const char* name, size_t length, Expression* value, + bool provide, bool hidden); + + // Add an assignment to the special dot symbol. + void + add_dot_assignment(Expression* value); + + // Add an assertion. + void + add_assertion(Expression* check, const char* message, size_t messagelen); + + // Add a data item to the current output section. + void + add_data(int size, bool is_signed, Expression* val); + + // Add a setting for the fill value. + void + add_fill(Expression* val); + + // Add an input section specification. + void + add_input_section(const Input_section_spec* spec, bool keep); + + // Return whether the output section is relro. + bool + is_relro() const + { return this->is_relro_; } + + // Record that the output section is relro. + void + set_is_relro() + { this->is_relro_ = true; } + + // Create any required output sections. + void + create_sections(Layout*); + + // Add any symbols being defined to the symbol table. + void + add_symbols_to_table(Symbol_table* symtab); + + // Finalize symbols and check assertions. + void + finalize_symbols(Symbol_table*, const Layout*, uint64_t*); + + // Return the output section name to use for an input file name and + // section name. + const char* + output_section_name(const char* file_name, const char* section_name, + Output_section***, Script_sections::Section_type*, + bool*); + + // Initialize OSP with an output section. + void + orphan_section_init(Orphan_section_placement* osp, + Script_sections::Elements_iterator p) + { osp->output_section_init(this->name_, this->output_section_, p); } + + // Set the section address. + void + set_section_addresses(Symbol_table* symtab, Layout* layout, + uint64_t* dot_value, uint64_t*, + uint64_t* load_address); + + // Check a constraint (ONLY_IF_RO, etc.) on an output section. If + // this section is constrained, and the input sections do not match, + // return the constraint, and set *POSD. + Section_constraint + check_constraint(Output_section_definition** posd); + + // See if this is the alternate output section for a constrained + // output section. If it is, transfer the Output_section and return + // true. Otherwise return false. + bool + alternate_constraint(Output_section_definition*, Section_constraint); + + // Get the list of segments to use for an allocated section when + // using a PHDRS clause. + Output_section* + allocate_to_segment(String_list** phdrs_list, bool* orphan); + + // Look for an output section by name and return the address, the + // load address, the alignment, and the size. This is used when an + // expression refers to an output section which was not actually + // created. This returns true if the section was found, false + // otherwise. + bool + get_output_section_info(const char*, uint64_t*, uint64_t*, uint64_t*, + uint64_t*) const; + + // Return the associated Output_section if there is one. + Output_section* + get_output_section() const + { return this->output_section_; } + + // Print the contents to the FILE. This is for debugging. + void + print(FILE*) const; + + // Return the output section type if specified or Script_sections::ST_NONE. + Script_sections::Section_type + section_type() const; + + // Store the memory region to use. + void + set_memory_region(Memory_region*, bool set_vma); + + void + set_section_vma(Expression* address) + { this->address_ = address; } + + void + set_section_lma(Expression* address) + { this->load_address_ = address; } + + const std::string& + get_section_name() const + { return this->name_; } + + private: + static const char* + script_section_type_name(Script_section_type); + + typedef std::vector<Output_section_element*> Output_section_elements; + + // The output section name. + std::string name_; + // The address. This may be NULL. + Expression* address_; + // The load address. This may be NULL. + Expression* load_address_; + // The alignment. This may be NULL. + Expression* align_; + // The input section alignment. This may be NULL. + Expression* subalign_; + // The constraint, if any. + Section_constraint constraint_; + // The fill value. This may be NULL. + Expression* fill_; + // The list of segments this section should go into. This may be + // NULL. + String_list* phdrs_; + // The list of elements defining the section. + Output_section_elements elements_; + // The Output_section created for this definition. This will be + // NULL if none was created. + Output_section* output_section_; + // The address after it has been evaluated. + uint64_t evaluated_address_; + // The load address after it has been evaluated. + uint64_t evaluated_load_address_; + // The alignment after it has been evaluated. + uint64_t evaluated_addralign_; + // The output section is relro. + bool is_relro_; + // The output section type if specified. + enum Script_section_type script_section_type_; +}; + +// Constructor. + +Output_section_definition::Output_section_definition( + const char* name, + size_t namelen, + const Parser_output_section_header* header) + : name_(name, namelen), + address_(header->address), + load_address_(header->load_address), + align_(header->align), + subalign_(header->subalign), + constraint_(header->constraint), + fill_(NULL), + phdrs_(NULL), + elements_(), + output_section_(NULL), + evaluated_address_(0), + evaluated_load_address_(0), + evaluated_addralign_(0), + is_relro_(false), + script_section_type_(header->section_type) +{ +} + +// Finish an output section. + +void +Output_section_definition::finish(const Parser_output_section_trailer* trailer) +{ + this->fill_ = trailer->fill; + this->phdrs_ = trailer->phdrs; +} + +// Add a symbol to be defined. + +void +Output_section_definition::add_symbol_assignment(const char* name, + size_t length, + Expression* value, + bool provide, + bool hidden) +{ + Output_section_element* p = new Output_section_element_assignment(name, + length, + value, + provide, + hidden); + this->elements_.push_back(p); +} + +// Add an assignment to the special dot symbol. + +void +Output_section_definition::add_dot_assignment(Expression* value) +{ + Output_section_element* p = new Output_section_element_dot_assignment(value); + this->elements_.push_back(p); +} + +// Add an assertion. + +void +Output_section_definition::add_assertion(Expression* check, + const char* message, + size_t messagelen) +{ + Output_section_element* p = new Output_section_element_assertion(check, + message, + messagelen); + this->elements_.push_back(p); +} + +// Add a data item to the current output section. + +void +Output_section_definition::add_data(int size, bool is_signed, Expression* val) +{ + Output_section_element* p = new Output_section_element_data(size, is_signed, + val); + this->elements_.push_back(p); +} + +// Add a setting for the fill value. + +void +Output_section_definition::add_fill(Expression* val) +{ + Output_section_element* p = new Output_section_element_fill(val); + this->elements_.push_back(p); +} + +// Add an input section specification. + +void +Output_section_definition::add_input_section(const Input_section_spec* spec, + bool keep) +{ + Output_section_element* p = new Output_section_element_input(spec, keep); + this->elements_.push_back(p); +} + +// Create any required output sections. We need an output section if +// there is a data statement here. + +void +Output_section_definition::create_sections(Layout* layout) +{ + if (this->output_section_ != NULL) + return; + for (Output_section_elements::const_iterator p = this->elements_.begin(); + p != this->elements_.end(); + ++p) + { + if ((*p)->needs_output_section()) + { + const char* name = this->name_.c_str(); + this->output_section_ = + layout->make_output_section_for_script(name, this->section_type()); + return; + } + } +} + +// Add any symbols being defined to the symbol table. + +void +Output_section_definition::add_symbols_to_table(Symbol_table* symtab) +{ + for (Output_section_elements::iterator p = this->elements_.begin(); + p != this->elements_.end(); + ++p) + (*p)->add_symbols_to_table(symtab); +} + +// Finalize symbols and check assertions. + +void +Output_section_definition::finalize_symbols(Symbol_table* symtab, + const Layout* layout, + uint64_t* dot_value) +{ + if (this->output_section_ != NULL) + *dot_value = this->output_section_->address(); + else + { + uint64_t address = *dot_value; + if (this->address_ != NULL) + { + address = this->address_->eval_with_dot(symtab, layout, true, + *dot_value, NULL, + NULL, NULL, false); + } + if (this->align_ != NULL) + { + uint64_t align = this->align_->eval_with_dot(symtab, layout, true, + *dot_value, NULL, + NULL, NULL, false); + address = align_address(address, align); + } + *dot_value = address; + } + + Output_section* dot_section = this->output_section_; + for (Output_section_elements::iterator p = this->elements_.begin(); + p != this->elements_.end(); + ++p) + (*p)->finalize_symbols(symtab, layout, dot_value, &dot_section); +} + +// Return the output section name to use for an input section name. + +const char* +Output_section_definition::output_section_name( + const char* file_name, + const char* section_name, + Output_section*** slot, + Script_sections::Section_type* psection_type, + bool* keep) +{ + // Ask each element whether it matches NAME. + for (Output_section_elements::const_iterator p = this->elements_.begin(); + p != this->elements_.end(); + ++p) + { + if ((*p)->match_name(file_name, section_name, keep)) + { + // We found a match for NAME, which means that it should go + // into this output section. + *slot = &this->output_section_; + *psection_type = this->section_type(); + return this->name_.c_str(); + } + } + + // We don't know about this section name. + return NULL; +} + +// Return true if memory from START to START + LENGTH is contained +// within a memory region. + +bool +Script_sections::block_in_region(Symbol_table* symtab, Layout* layout, + uint64_t start, uint64_t length) const +{ + if (this->memory_regions_ == NULL) + return false; + + for (Memory_regions::const_iterator mr = this->memory_regions_->begin(); + mr != this->memory_regions_->end(); + ++mr) + { + uint64_t s = (*mr)->start_address()->eval(symtab, layout, false); + uint64_t l = (*mr)->length()->eval(symtab, layout, false); + + if (s <= start + && (s + l) >= (start + length)) + return true; + } + + return false; +} + +// Find a memory region that should be used by a given output SECTION. +// If provided set PREVIOUS_SECTION_RETURN to point to the last section +// that used the return memory region. + +Memory_region* +Script_sections::find_memory_region( + Output_section_definition* section, + bool find_vma_region, + Output_section_definition** previous_section_return) +{ + if (previous_section_return != NULL) + * previous_section_return = NULL; + + // Walk the memory regions specified in this script, if any. + if (this->memory_regions_ == NULL) + return NULL; + + // The /DISCARD/ section never gets assigned to any region. + if (section->get_section_name() == "/DISCARD/") + return NULL; + + Memory_region* first_match = NULL; + + // First check to see if a region has been assigned to this section. + for (Memory_regions::const_iterator mr = this->memory_regions_->begin(); + mr != this->memory_regions_->end(); + ++mr) + { + if (find_vma_region) + { + for (Memory_region::Section_list::const_iterator s = + (*mr)->get_vma_section_list_start(); + s != (*mr)->get_vma_section_list_end(); + ++s) + if ((*s) == section) + { + (*mr)->set_last_section(section); + return *mr; + } + } + else + { + for (Memory_region::Section_list::const_iterator s = + (*mr)->get_lma_section_list_start(); + s != (*mr)->get_lma_section_list_end(); + ++s) + if ((*s) == section) + { + (*mr)->set_last_section(section); + return *mr; + } + } + + // Make a note of the first memory region whose attributes + // are compatible with the section. If we do not find an + // explicit region assignment, then we will return this region. + Output_section* out_sec = section->get_output_section(); + if (first_match == NULL + && out_sec != NULL + && (*mr)->attributes_compatible(out_sec->flags(), + out_sec->type())) + first_match = *mr; + } + + // With LMA computations, if an explicit region has not been specified then + // we will want to set the difference between the VMA and the LMA of the + // section were searching for to be the same as the difference between the + // VMA and LMA of the last section to be added to first matched region. + // Hence, if it was asked for, we return a pointer to the last section + // known to be used by the first matched region. + if (first_match != NULL + && previous_section_return != NULL) + *previous_section_return = first_match->get_last_section(); + + return first_match; +} + +// Set the section address. Note that the OUTPUT_SECTION_ field will +// be NULL if no input sections were mapped to this output section. +// We still have to adjust dot and process symbol assignments. + +void +Output_section_definition::set_section_addresses(Symbol_table* symtab, + Layout* layout, + uint64_t* dot_value, + uint64_t* dot_alignment, + uint64_t* load_address) +{ + Memory_region* vma_region = NULL; + Memory_region* lma_region = NULL; + Script_sections* script_sections = + layout->script_options()->script_sections(); + uint64_t address; + uint64_t old_dot_value = *dot_value; + uint64_t old_load_address = *load_address; + + // If input section sorting is requested via --section-ordering-file or + // linker plugins, then do it here. This is important because we want + // any sorting specified in the linker scripts, which will be done after + // this, to take precedence. The final order of input sections is then + // guaranteed to be according to the linker script specification. + if (this->output_section_ != NULL + && this->output_section_->input_section_order_specified()) + this->output_section_->sort_attached_input_sections(); + + // Decide the start address for the section. The algorithm is: + // 1) If an address has been specified in a linker script, use that. + // 2) Otherwise if a memory region has been specified for the section, + // use the next free address in the region. + // 3) Otherwise if memory regions have been specified find the first + // region whose attributes are compatible with this section and + // install it into that region. + // 4) Otherwise use the current location counter. + + if (this->output_section_ != NULL + // Check for --section-start. + && parameters->options().section_start(this->output_section_->name(), + &address)) + ; + else if (this->address_ == NULL) + { + vma_region = script_sections->find_memory_region(this, true, NULL); + + if (vma_region != NULL) + address = vma_region->get_current_address()->eval(symtab, layout, + false); + else + address = *dot_value; + } + else + address = this->address_->eval_with_dot(symtab, layout, true, + *dot_value, NULL, NULL, + dot_alignment, false); + uint64_t align; + if (this->align_ == NULL) + { + if (this->output_section_ == NULL) + align = 0; + else + align = this->output_section_->addralign(); + } + else + { + Output_section* align_section; + align = this->align_->eval_with_dot(symtab, layout, true, *dot_value, + NULL, &align_section, NULL, false); + if (align_section != NULL) + gold_warning(_("alignment of section %s is not absolute"), + this->name_.c_str()); + if (this->output_section_ != NULL) + this->output_section_->set_addralign(align); + } + + address = align_address(address, align); + + uint64_t start_address = address; + + *dot_value = address; + + // Except for NOLOAD sections, the address of non-SHF_ALLOC sections is + // forced to zero, regardless of what the linker script wants. + if (this->output_section_ != NULL + && ((this->output_section_->flags() & elfcpp::SHF_ALLOC) != 0 + || this->output_section_->is_noload())) + this->output_section_->set_address(address); + + this->evaluated_address_ = address; + this->evaluated_addralign_ = align; + + uint64_t laddr; + + if (this->load_address_ == NULL) + { + Output_section_definition* previous_section; + + // Determine if an LMA region has been set for this section. + lma_region = script_sections->find_memory_region(this, false, + &previous_section); + + if (lma_region != NULL) + { + if (previous_section == NULL) + // The LMA address was explicitly set to the given region. + laddr = lma_region->get_current_address()->eval(symtab, layout, + false); + else + { + // We are not going to use the discovered lma_region, so + // make sure that we do not update it in the code below. + lma_region = NULL; + + if (this->address_ != NULL || previous_section == this) + { + // Either an explicit VMA address has been set, or an + // explicit VMA region has been set, so set the LMA equal to + // the VMA. + laddr = address; + } + else + { + // The LMA address was not explicitly or implicitly set. + // + // We have been given the first memory region that is + // compatible with the current section and a pointer to the + // last section to use this region. Set the LMA of this + // section so that the difference between its' VMA and LMA + // is the same as the difference between the VMA and LMA of + // the last section in the given region. + laddr = address + (previous_section->evaluated_load_address_ + - previous_section->evaluated_address_); + } + } + + if (this->output_section_ != NULL) + this->output_section_->set_load_address(laddr); + } + else + { + // Do not set the load address of the output section, if one exists. + // This allows future sections to determine what the load address + // should be. If none is ever set, it will default to being the + // same as the vma address. + laddr = address; + } + } + else + { + laddr = this->load_address_->eval_with_dot(symtab, layout, true, + *dot_value, + this->output_section_, + NULL, NULL, false); + if (this->output_section_ != NULL) + this->output_section_->set_load_address(laddr); + } + + this->evaluated_load_address_ = laddr; + + uint64_t subalign; + if (this->subalign_ == NULL) + subalign = 0; + else + { + Output_section* subalign_section; + subalign = this->subalign_->eval_with_dot(symtab, layout, true, + *dot_value, NULL, + &subalign_section, NULL, + false); + if (subalign_section != NULL) + gold_warning(_("subalign of section %s is not absolute"), + this->name_.c_str()); + } + + std::string fill; + if (this->fill_ != NULL) + { + // FIXME: The GNU linker supports fill values of arbitrary + // length. + Output_section* fill_section; + uint64_t fill_val = this->fill_->eval_with_dot(symtab, layout, true, + *dot_value, + NULL, &fill_section, + NULL, false); + if (fill_section != NULL) + gold_warning(_("fill of section %s is not absolute"), + this->name_.c_str()); + unsigned char fill_buff[4]; + elfcpp::Swap_unaligned<32, true>::writeval(fill_buff, fill_val); + fill.assign(reinterpret_cast<char*>(fill_buff), 4); + } + + Input_section_list input_sections; + if (this->output_section_ != NULL) + { + // Get the list of input sections attached to this output + // section. This will leave the output section with only + // Output_section_data entries. + address += this->output_section_->get_input_sections(address, + fill, + &input_sections); + *dot_value = address; + } + + Output_section* dot_section = this->output_section_; + for (Output_section_elements::iterator p = this->elements_.begin(); + p != this->elements_.end(); + ++p) + (*p)->set_section_addresses(symtab, layout, this->output_section_, + subalign, dot_value, dot_alignment, + &dot_section, &fill, &input_sections); + + gold_assert(input_sections.empty()); + + if (vma_region != NULL) + { + // Update the VMA region being used by the section now that we know how + // big it is. Use the current address in the region, rather than + // start_address because that might have been aligned upwards and we + // need to allow for the padding. + Expression* addr = vma_region->get_current_address(); + uint64_t size = *dot_value - addr->eval(symtab, layout, false); + + vma_region->increment_offset(this->get_section_name(), size, + symtab, layout); + } + + // If the LMA region is different from the VMA region, then increment the + // offset there as well. Note that we use the same "dot_value - + // start_address" formula that is used in the load_address assignment below. + if (lma_region != NULL && lma_region != vma_region) + lma_region->increment_offset(this->get_section_name(), + *dot_value - start_address, + symtab, layout); + + // Compute the load address for the following section. + if (this->output_section_ == NULL) + *load_address = *dot_value; + else if (this->load_address_ == NULL) + { + if (lma_region == NULL) + *load_address = *dot_value; + else + *load_address = + lma_region->get_current_address()->eval(symtab, layout, false); + } + else + *load_address = (this->output_section_->load_address() + + (*dot_value - start_address)); + + if (this->output_section_ != NULL) + { + if (this->is_relro_) + this->output_section_->set_is_relro(); + else + this->output_section_->clear_is_relro(); + + // If this is a NOLOAD section, keep dot and load address unchanged. + if (this->output_section_->is_noload()) + { + *dot_value = old_dot_value; + *load_address = old_load_address; + } + } +} + +// Check a constraint (ONLY_IF_RO, etc.) on an output section. If +// this section is constrained, and the input sections do not match, +// return the constraint, and set *POSD. + +Section_constraint +Output_section_definition::check_constraint(Output_section_definition** posd) +{ + switch (this->constraint_) + { + case CONSTRAINT_NONE: + return CONSTRAINT_NONE; + + case CONSTRAINT_ONLY_IF_RO: + if (this->output_section_ != NULL + && (this->output_section_->flags() & elfcpp::SHF_WRITE) != 0) + { + *posd = this; + return CONSTRAINT_ONLY_IF_RO; + } + return CONSTRAINT_NONE; + + case CONSTRAINT_ONLY_IF_RW: + if (this->output_section_ != NULL + && (this->output_section_->flags() & elfcpp::SHF_WRITE) == 0) + { + *posd = this; + return CONSTRAINT_ONLY_IF_RW; + } + return CONSTRAINT_NONE; + + case CONSTRAINT_SPECIAL: + if (this->output_section_ != NULL) + gold_error(_("SPECIAL constraints are not implemented")); + return CONSTRAINT_NONE; + + default: + gold_unreachable(); + } +} + +// See if this is the alternate output section for a constrained +// output section. If it is, transfer the Output_section and return +// true. Otherwise return false. + +bool +Output_section_definition::alternate_constraint( + Output_section_definition* posd, + Section_constraint constraint) +{ + if (this->name_ != posd->name_) + return false; + + switch (constraint) + { + case CONSTRAINT_ONLY_IF_RO: + if (this->constraint_ != CONSTRAINT_ONLY_IF_RW) + return false; + break; + + case CONSTRAINT_ONLY_IF_RW: + if (this->constraint_ != CONSTRAINT_ONLY_IF_RO) + return false; + break; + + default: + gold_unreachable(); + } + + // We have found the alternate constraint. We just need to move + // over the Output_section. When constraints are used properly, + // THIS should not have an output_section pointer, as all the input + // sections should have matched the other definition. + + if (this->output_section_ != NULL) + gold_error(_("mismatched definition for constrained sections")); + + this->output_section_ = posd->output_section_; + posd->output_section_ = NULL; + + if (this->is_relro_) + this->output_section_->set_is_relro(); + else + this->output_section_->clear_is_relro(); + + return true; +} + +// Get the list of segments to use for an allocated section when using +// a PHDRS clause. + +Output_section* +Output_section_definition::allocate_to_segment(String_list** phdrs_list, + bool* orphan) +{ + // Update phdrs_list even if we don't have an output section. It + // might be used by the following sections. + if (this->phdrs_ != NULL) + *phdrs_list = this->phdrs_; + + if (this->output_section_ == NULL) + return NULL; + if ((this->output_section_->flags() & elfcpp::SHF_ALLOC) == 0) + return NULL; + *orphan = false; + return this->output_section_; +} + +// Look for an output section by name and return the address, the load +// address, the alignment, and the size. This is used when an +// expression refers to an output section which was not actually +// created. This returns true if the section was found, false +// otherwise. + +bool +Output_section_definition::get_output_section_info(const char* name, + uint64_t* address, + uint64_t* load_address, + uint64_t* addralign, + uint64_t* size) const +{ + if (this->name_ != name) + return false; + + if (this->output_section_ != NULL) + { + *address = this->output_section_->address(); + if (this->output_section_->has_load_address()) + *load_address = this->output_section_->load_address(); + else + *load_address = *address; + *addralign = this->output_section_->addralign(); + *size = this->output_section_->current_data_size(); + } + else + { + *address = this->evaluated_address_; + *load_address = this->evaluated_load_address_; + *addralign = this->evaluated_addralign_; + *size = 0; + } + + return true; +} + +// Print for debugging. + +void +Output_section_definition::print(FILE* f) const +{ + fprintf(f, " %s ", this->name_.c_str()); + + if (this->address_ != NULL) + { + this->address_->print(f); + fprintf(f, " "); + } + + if (this->script_section_type_ != SCRIPT_SECTION_TYPE_NONE) + fprintf(f, "(%s) ", + this->script_section_type_name(this->script_section_type_)); + + fprintf(f, ": "); + + if (this->load_address_ != NULL) + { + fprintf(f, "AT("); + this->load_address_->print(f); + fprintf(f, ") "); + } + + if (this->align_ != NULL) + { + fprintf(f, "ALIGN("); + this->align_->print(f); + fprintf(f, ") "); + } + + if (this->subalign_ != NULL) + { + fprintf(f, "SUBALIGN("); + this->subalign_->print(f); + fprintf(f, ") "); + } + + fprintf(f, "{\n"); + + for (Output_section_elements::const_iterator p = this->elements_.begin(); + p != this->elements_.end(); + ++p) + (*p)->print(f); + + fprintf(f, " }"); + + if (this->fill_ != NULL) + { + fprintf(f, " = "); + this->fill_->print(f); + } + + if (this->phdrs_ != NULL) + { + for (String_list::const_iterator p = this->phdrs_->begin(); + p != this->phdrs_->end(); + ++p) + fprintf(f, " :%s", p->c_str()); + } + + fprintf(f, "\n"); +} + +Script_sections::Section_type +Output_section_definition::section_type() const +{ + switch (this->script_section_type_) + { + case SCRIPT_SECTION_TYPE_NONE: + return Script_sections::ST_NONE; + case SCRIPT_SECTION_TYPE_NOLOAD: + return Script_sections::ST_NOLOAD; + case SCRIPT_SECTION_TYPE_COPY: + case SCRIPT_SECTION_TYPE_DSECT: + case SCRIPT_SECTION_TYPE_INFO: + case SCRIPT_SECTION_TYPE_OVERLAY: + // There are not really support so we treat them as ST_NONE. The + // parse should have issued errors for them already. + return Script_sections::ST_NONE; + default: + gold_unreachable(); + } +} + +// Return the name of a script section type. + +const char* +Output_section_definition::script_section_type_name( + Script_section_type script_section_type) +{ + switch (script_section_type) + { + case SCRIPT_SECTION_TYPE_NONE: + return "NONE"; + case SCRIPT_SECTION_TYPE_NOLOAD: + return "NOLOAD"; + case SCRIPT_SECTION_TYPE_DSECT: + return "DSECT"; + case SCRIPT_SECTION_TYPE_COPY: + return "COPY"; + case SCRIPT_SECTION_TYPE_INFO: + return "INFO"; + case SCRIPT_SECTION_TYPE_OVERLAY: + return "OVERLAY"; + default: + gold_unreachable(); + } +} + +void +Output_section_definition::set_memory_region(Memory_region* mr, bool set_vma) +{ + gold_assert(mr != NULL); + // Add the current section to the specified region's list. + mr->add_section(this, set_vma); +} + +// An output section created to hold orphaned input sections. These +// do not actually appear in linker scripts. However, for convenience +// when setting the output section addresses, we put a marker to these +// sections in the appropriate place in the list of SECTIONS elements. + +class Orphan_output_section : public Sections_element +{ + public: + Orphan_output_section(Output_section* os) + : os_(os) + { } + + // Return whether the orphan output section is relro. We can just + // check the output section because we always set the flag, if + // needed, just after we create the Orphan_output_section. + bool + is_relro() const + { return this->os_->is_relro(); } + + // Initialize OSP with an output section. This should have been + // done already. + void + orphan_section_init(Orphan_section_placement*, + Script_sections::Elements_iterator) + { gold_unreachable(); } + + // Set section addresses. + void + set_section_addresses(Symbol_table*, Layout*, uint64_t*, uint64_t*, + uint64_t*); + + // Get the list of segments to use for an allocated section when + // using a PHDRS clause. + Output_section* + allocate_to_segment(String_list**, bool*); + + // Return the associated Output_section. + Output_section* + get_output_section() const + { return this->os_; } + + // Print for debugging. + void + print(FILE* f) const + { + fprintf(f, " marker for orphaned output section %s\n", + this->os_->name()); + } + + private: + Output_section* os_; +}; + +// Set section addresses. + +void +Orphan_output_section::set_section_addresses(Symbol_table*, Layout*, + uint64_t* dot_value, + uint64_t*, + uint64_t* load_address) +{ + typedef std::list<Output_section::Input_section> Input_section_list; + + bool have_load_address = *load_address != *dot_value; + + uint64_t address = *dot_value; + address = align_address(address, this->os_->addralign()); + + // If input section sorting is requested via --section-ordering-file or + // linker plugins, then do it here. This is important because we want + // any sorting specified in the linker scripts, which will be done after + // this, to take precedence. The final order of input sections is then + // guaranteed to be according to the linker script specification. + if (this->os_ != NULL + && this->os_->input_section_order_specified()) + this->os_->sort_attached_input_sections(); + + // For a relocatable link, all orphan sections are put at + // address 0. In general we expect all sections to be at + // address 0 for a relocatable link, but we permit the linker + // script to override that for specific output sections. + if (parameters->options().relocatable()) + { + address = 0; + *load_address = 0; + have_load_address = false; + } + + if ((this->os_->flags() & elfcpp::SHF_ALLOC) != 0) + { + this->os_->set_address(address); + if (have_load_address) + this->os_->set_load_address(align_address(*load_address, + this->os_->addralign())); + } + + Input_section_list input_sections; + address += this->os_->get_input_sections(address, "", &input_sections); + + for (Input_section_list::iterator p = input_sections.begin(); + p != input_sections.end(); + ++p) + { + uint64_t addralign = p->addralign(); + if (!p->is_input_section()) + p->output_section_data()->finalize_data_size(); + uint64_t size = p->data_size(); + address = align_address(address, addralign); + this->os_->add_script_input_section(*p); + address += size; + } + + if (parameters->options().relocatable()) + { + // For a relocatable link, reset DOT_VALUE to 0. + *dot_value = 0; + *load_address = 0; + } + else if (this->os_ == NULL + || (this->os_->flags() & elfcpp::SHF_TLS) == 0 + || this->os_->type() != elfcpp::SHT_NOBITS) + { + // An SHF_TLS/SHT_NOBITS section does not take up any address space. + if (!have_load_address) + *load_address = address; + else + *load_address += address - *dot_value; + + *dot_value = address; + } +} + +// Get the list of segments to use for an allocated section when using +// a PHDRS clause. If this is an allocated section, return the +// Output_section. We don't change the list of segments. + +Output_section* +Orphan_output_section::allocate_to_segment(String_list**, bool* orphan) +{ + if ((this->os_->flags() & elfcpp::SHF_ALLOC) == 0) + return NULL; + *orphan = true; + return this->os_; +} + +// Class Phdrs_element. A program header from a PHDRS clause. + +class Phdrs_element +{ + public: + Phdrs_element(const char* name, size_t namelen, unsigned int type, + bool includes_filehdr, bool includes_phdrs, + bool is_flags_valid, unsigned int flags, + Expression* load_address) + : name_(name, namelen), type_(type), includes_filehdr_(includes_filehdr), + includes_phdrs_(includes_phdrs), is_flags_valid_(is_flags_valid), + flags_(flags), load_address_(load_address), load_address_value_(0), + segment_(NULL) + { } + + // Return the name of this segment. + const std::string& + name() const + { return this->name_; } + + // Return the type of the segment. + unsigned int + type() const + { return this->type_; } + + // Whether to include the file header. + bool + includes_filehdr() const + { return this->includes_filehdr_; } + + // Whether to include the program headers. + bool + includes_phdrs() const + { return this->includes_phdrs_; } + + // Return whether there is a load address. + bool + has_load_address() const + { return this->load_address_ != NULL; } + + // Evaluate the load address expression if there is one. + void + eval_load_address(Symbol_table* symtab, Layout* layout) + { + if (this->load_address_ != NULL) + this->load_address_value_ = this->load_address_->eval(symtab, layout, + true); + } + + // Return the load address. + uint64_t + load_address() const + { + gold_assert(this->load_address_ != NULL); + return this->load_address_value_; + } + + // Create the segment. + Output_segment* + create_segment(Layout* layout) + { + this->segment_ = layout->make_output_segment(this->type_, this->flags_); + return this->segment_; + } + + // Return the segment. + Output_segment* + segment() + { return this->segment_; } + + // Release the segment. + void + release_segment() + { this->segment_ = NULL; } + + // Set the segment flags if appropriate. + void + set_flags_if_valid() + { + if (this->is_flags_valid_) + this->segment_->set_flags(this->flags_); + } + + // Print for debugging. + void + print(FILE*) const; + + private: + // The name used in the script. + std::string name_; + // The type of the segment (PT_LOAD, etc.). + unsigned int type_; + // Whether this segment includes the file header. + bool includes_filehdr_; + // Whether this segment includes the section headers. + bool includes_phdrs_; + // Whether the flags were explicitly specified. + bool is_flags_valid_; + // The flags for this segment (PF_R, etc.) if specified. + unsigned int flags_; + // The expression for the load address for this segment. This may + // be NULL. + Expression* load_address_; + // The actual load address from evaluating the expression. + uint64_t load_address_value_; + // The segment itself. + Output_segment* segment_; +}; + +// Print for debugging. + +void +Phdrs_element::print(FILE* f) const +{ + fprintf(f, " %s 0x%x", this->name_.c_str(), this->type_); + if (this->includes_filehdr_) + fprintf(f, " FILEHDR"); + if (this->includes_phdrs_) + fprintf(f, " PHDRS"); + if (this->is_flags_valid_) + fprintf(f, " FLAGS(%u)", this->flags_); + if (this->load_address_ != NULL) + { + fprintf(f, " AT("); + this->load_address_->print(f); + fprintf(f, ")"); + } + fprintf(f, ";\n"); +} + +// Add a memory region. + +void +Script_sections::add_memory_region(const char* name, size_t namelen, + unsigned int attributes, + Expression* start, Expression* length) +{ + if (this->memory_regions_ == NULL) + this->memory_regions_ = new Memory_regions(); + else if (this->find_memory_region(name, namelen)) + { + gold_error(_("region '%.*s' already defined"), static_cast<int>(namelen), + name); + // FIXME: Add a GOLD extension to allow multiple regions with the same + // name. This would amount to a single region covering disjoint blocks + // of memory, which is useful for embedded devices. + } + + // FIXME: Check the length and start values. Currently we allow + // non-constant expressions for these values, whereas LD does not. + + // FIXME: Add a GOLD extension to allow NEGATIVE LENGTHS. This would + // describe a region that packs from the end address going down, rather + // than the start address going up. This would be useful for embedded + // devices. + + this->memory_regions_->push_back(new Memory_region(name, namelen, attributes, + start, length)); +} + +// Find a memory region. + +Memory_region* +Script_sections::find_memory_region(const char* name, size_t namelen) +{ + if (this->memory_regions_ == NULL) + return NULL; + + for (Memory_regions::const_iterator m = this->memory_regions_->begin(); + m != this->memory_regions_->end(); + ++m) + if ((*m)->name_match(name, namelen)) + return *m; + + return NULL; +} + +// Find a memory region's origin. + +Expression* +Script_sections::find_memory_region_origin(const char* name, size_t namelen) +{ + Memory_region* mr = find_memory_region(name, namelen); + if (mr == NULL) + return NULL; + + return mr->start_address(); +} + +// Find a memory region's length. + +Expression* +Script_sections::find_memory_region_length(const char* name, size_t namelen) +{ + Memory_region* mr = find_memory_region(name, namelen); + if (mr == NULL) + return NULL; + + return mr->length(); +} + +// Set the memory region to use for the current section. + +void +Script_sections::set_memory_region(Memory_region* mr, bool set_vma) +{ + gold_assert(!this->sections_elements_->empty()); + this->sections_elements_->back()->set_memory_region(mr, set_vma); +} + +// Class Script_sections. + +Script_sections::Script_sections() + : saw_sections_clause_(false), + in_sections_clause_(false), + sections_elements_(NULL), + output_section_(NULL), + memory_regions_(NULL), + phdrs_elements_(NULL), + orphan_section_placement_(NULL), + data_segment_align_start_(), + saw_data_segment_align_(false), + saw_relro_end_(false), + saw_segment_start_expression_(false) +{ +} + +// Start a SECTIONS clause. + +void +Script_sections::start_sections() +{ + gold_assert(!this->in_sections_clause_ && this->output_section_ == NULL); + this->saw_sections_clause_ = true; + this->in_sections_clause_ = true; + if (this->sections_elements_ == NULL) + this->sections_elements_ = new Sections_elements; +} + +// Finish a SECTIONS clause. + +void +Script_sections::finish_sections() +{ + gold_assert(this->in_sections_clause_ && this->output_section_ == NULL); + this->in_sections_clause_ = false; +} + +// Add a symbol to be defined. + +void +Script_sections::add_symbol_assignment(const char* name, size_t length, + Expression* val, bool provide, + bool hidden) +{ + if (this->output_section_ != NULL) + this->output_section_->add_symbol_assignment(name, length, val, + provide, hidden); + else + { + Sections_element* p = new Sections_element_assignment(name, length, + val, provide, + hidden); + this->sections_elements_->push_back(p); + } +} + +// Add an assignment to the special dot symbol. + +void +Script_sections::add_dot_assignment(Expression* val) +{ + if (this->output_section_ != NULL) + this->output_section_->add_dot_assignment(val); + else + { + // The GNU linker permits assignments to . to appears outside of + // a SECTIONS clause, and treats it as appearing inside, so + // sections_elements_ may be NULL here. + if (this->sections_elements_ == NULL) + { + this->sections_elements_ = new Sections_elements; + this->saw_sections_clause_ = true; + } + + Sections_element* p = new Sections_element_dot_assignment(val); + this->sections_elements_->push_back(p); + } +} + +// Add an assertion. + +void +Script_sections::add_assertion(Expression* check, const char* message, + size_t messagelen) +{ + if (this->output_section_ != NULL) + this->output_section_->add_assertion(check, message, messagelen); + else + { + Sections_element* p = new Sections_element_assertion(check, message, + messagelen); + this->sections_elements_->push_back(p); + } +} + +// Start processing entries for an output section. + +void +Script_sections::start_output_section( + const char* name, + size_t namelen, + const Parser_output_section_header* header) +{ + Output_section_definition* posd = new Output_section_definition(name, + namelen, + header); + this->sections_elements_->push_back(posd); + gold_assert(this->output_section_ == NULL); + this->output_section_ = posd; +} + +// Stop processing entries for an output section. + +void +Script_sections::finish_output_section( + const Parser_output_section_trailer* trailer) +{ + gold_assert(this->output_section_ != NULL); + this->output_section_->finish(trailer); + this->output_section_ = NULL; +} + +// Add a data item to the current output section. + +void +Script_sections::add_data(int size, bool is_signed, Expression* val) +{ + gold_assert(this->output_section_ != NULL); + this->output_section_->add_data(size, is_signed, val); +} + +// Add a fill value setting to the current output section. + +void +Script_sections::add_fill(Expression* val) +{ + gold_assert(this->output_section_ != NULL); + this->output_section_->add_fill(val); +} + +// Add an input section specification to the current output section. + +void +Script_sections::add_input_section(const Input_section_spec* spec, bool keep) +{ + gold_assert(this->output_section_ != NULL); + this->output_section_->add_input_section(spec, keep); +} + +// This is called when we see DATA_SEGMENT_ALIGN. It means that any +// subsequent output sections may be relro. + +void +Script_sections::data_segment_align() +{ + if (this->saw_data_segment_align_) + gold_error(_("DATA_SEGMENT_ALIGN may only appear once in a linker script")); + gold_assert(!this->sections_elements_->empty()); + Sections_elements::iterator p = this->sections_elements_->end(); + --p; + this->data_segment_align_start_ = p; + this->saw_data_segment_align_ = true; +} + +// This is called when we see DATA_SEGMENT_RELRO_END. It means that +// any output sections seen since DATA_SEGMENT_ALIGN are relro. + +void +Script_sections::data_segment_relro_end() +{ + if (this->saw_relro_end_) + gold_error(_("DATA_SEGMENT_RELRO_END may only appear once " + "in a linker script")); + this->saw_relro_end_ = true; + + if (!this->saw_data_segment_align_) + gold_error(_("DATA_SEGMENT_RELRO_END must follow DATA_SEGMENT_ALIGN")); + else + { + Sections_elements::iterator p = this->data_segment_align_start_; + for (++p; p != this->sections_elements_->end(); ++p) + (*p)->set_is_relro(); + } +} + +// Create any required sections. + +void +Script_sections::create_sections(Layout* layout) +{ + if (!this->saw_sections_clause_) + return; + for (Sections_elements::iterator p = this->sections_elements_->begin(); + p != this->sections_elements_->end(); + ++p) + (*p)->create_sections(layout); +} + +// Add any symbols we are defining to the symbol table. + +void +Script_sections::add_symbols_to_table(Symbol_table* symtab) +{ + if (!this->saw_sections_clause_) + return; + for (Sections_elements::iterator p = this->sections_elements_->begin(); + p != this->sections_elements_->end(); + ++p) + (*p)->add_symbols_to_table(symtab); +} + +// Finalize symbols and check assertions. + +void +Script_sections::finalize_symbols(Symbol_table* symtab, const Layout* layout) +{ + if (!this->saw_sections_clause_) + return; + uint64_t dot_value = 0; + for (Sections_elements::iterator p = this->sections_elements_->begin(); + p != this->sections_elements_->end(); + ++p) + (*p)->finalize_symbols(symtab, layout, &dot_value); +} + +// Return the name of the output section to use for an input file name +// and section name. + +const char* +Script_sections::output_section_name( + const char* file_name, + const char* section_name, + Output_section*** output_section_slot, + Script_sections::Section_type* psection_type, + bool* keep) +{ + for (Sections_elements::const_iterator p = this->sections_elements_->begin(); + p != this->sections_elements_->end(); + ++p) + { + const char* ret = (*p)->output_section_name(file_name, section_name, + output_section_slot, + psection_type, keep); + + if (ret != NULL) + { + // The special name /DISCARD/ means that the input section + // should be discarded. + if (strcmp(ret, "/DISCARD/") == 0) + { + *output_section_slot = NULL; + *psection_type = Script_sections::ST_NONE; + return NULL; + } + return ret; + } + } + + // If we couldn't find a mapping for the name, the output section + // gets the name of the input section. + + *output_section_slot = NULL; + *psection_type = Script_sections::ST_NONE; + + return section_name; +} + +// Place a marker for an orphan output section into the SECTIONS +// clause. + +void +Script_sections::place_orphan(Output_section* os) +{ + Orphan_section_placement* osp = this->orphan_section_placement_; + if (osp == NULL) + { + // Initialize the Orphan_section_placement structure. + osp = new Orphan_section_placement(); + for (Sections_elements::iterator p = this->sections_elements_->begin(); + p != this->sections_elements_->end(); + ++p) + (*p)->orphan_section_init(osp, p); + gold_assert(!this->sections_elements_->empty()); + Sections_elements::iterator last = this->sections_elements_->end(); + --last; + osp->last_init(last); + this->orphan_section_placement_ = osp; + } + + Orphan_output_section* orphan = new Orphan_output_section(os); + + // Look for where to put ORPHAN. + Sections_elements::iterator* where; + if (osp->find_place(os, &where)) + { + if ((**where)->is_relro()) + os->set_is_relro(); + else + os->clear_is_relro(); + + // We want to insert ORPHAN after *WHERE, and then update *WHERE + // so that the next one goes after this one. + Sections_elements::iterator p = *where; + gold_assert(p != this->sections_elements_->end()); + ++p; + *where = this->sections_elements_->insert(p, orphan); + } + else + { + os->clear_is_relro(); + // We don't have a place to put this orphan section. Put it, + // and all other sections like it, at the end, but before the + // sections which always come at the end. + Sections_elements::iterator last = osp->last_place(); + *where = this->sections_elements_->insert(last, orphan); + } +} + +// Set the addresses of all the output sections. Walk through all the +// elements, tracking the dot symbol. Apply assignments which set +// absolute symbol values, in case they are used when setting dot. +// Fill in data statement values. As we find output sections, set the +// address, set the address of all associated input sections, and +// update dot. Return the segment which should hold the file header +// and segment headers, if any. + +Output_segment* +Script_sections::set_section_addresses(Symbol_table* symtab, Layout* layout) +{ + gold_assert(this->saw_sections_clause_); + + // Implement ONLY_IF_RO/ONLY_IF_RW constraints. These are a pain + // for our representation. + for (Sections_elements::iterator p = this->sections_elements_->begin(); + p != this->sections_elements_->end(); + ++p) + { + Output_section_definition* posd; + Section_constraint failed_constraint = (*p)->check_constraint(&posd); + if (failed_constraint != CONSTRAINT_NONE) + { + Sections_elements::iterator q; + for (q = this->sections_elements_->begin(); + q != this->sections_elements_->end(); + ++q) + { + if (q != p) + { + if ((*q)->alternate_constraint(posd, failed_constraint)) + break; + } + } + + if (q == this->sections_elements_->end()) + gold_error(_("no matching section constraint")); + } + } + + // Force the alignment of the first TLS section to be the maximum + // alignment of all TLS sections. + Output_section* first_tls = NULL; + uint64_t tls_align = 0; + for (Sections_elements::const_iterator p = this->sections_elements_->begin(); + p != this->sections_elements_->end(); + ++p) + { + Output_section* os = (*p)->get_output_section(); + if (os != NULL && (os->flags() & elfcpp::SHF_TLS) != 0) + { + if (first_tls == NULL) + first_tls = os; + if (os->addralign() > tls_align) + tls_align = os->addralign(); + } + } + if (first_tls != NULL) + first_tls->set_addralign(tls_align); + + // For a relocatable link, we implicitly set dot to zero. + uint64_t dot_value = 0; + uint64_t dot_alignment = 0; + uint64_t load_address = 0; + + // Check to see if we want to use any of -Ttext, -Tdata and -Tbss options + // to set section addresses. If the script has any SEGMENT_START + // expression, we do not set the section addresses. + bool use_tsection_options = + (!this->saw_segment_start_expression_ + && (parameters->options().user_set_Ttext() + || parameters->options().user_set_Tdata() + || parameters->options().user_set_Tbss())); + + for (Sections_elements::iterator p = this->sections_elements_->begin(); + p != this->sections_elements_->end(); + ++p) + { + Output_section* os = (*p)->get_output_section(); + + // Handle -Ttext, -Tdata and -Tbss options. We do this by looking for + // the special sections by names and doing dot assignments. + if (use_tsection_options + && os != NULL + && (os->flags() & elfcpp::SHF_ALLOC) != 0) + { + uint64_t new_dot_value = dot_value; + + if (parameters->options().user_set_Ttext() + && strcmp(os->name(), ".text") == 0) + new_dot_value = parameters->options().Ttext(); + else if (parameters->options().user_set_Tdata() + && strcmp(os->name(), ".data") == 0) + new_dot_value = parameters->options().Tdata(); + else if (parameters->options().user_set_Tbss() + && strcmp(os->name(), ".bss") == 0) + new_dot_value = parameters->options().Tbss(); + + // Update dot and load address if necessary. + if (new_dot_value < dot_value) + gold_error(_("dot may not move backward")); + else if (new_dot_value != dot_value) + { + dot_value = new_dot_value; + load_address = new_dot_value; + } + } + + (*p)->set_section_addresses(symtab, layout, &dot_value, &dot_alignment, + &load_address); + } + + if (this->phdrs_elements_ != NULL) + { + for (Phdrs_elements::iterator p = this->phdrs_elements_->begin(); + p != this->phdrs_elements_->end(); + ++p) + (*p)->eval_load_address(symtab, layout); + } + + return this->create_segments(layout, dot_alignment); +} + +// Sort the sections in order to put them into segments. + +class Sort_output_sections +{ + public: + Sort_output_sections(const Script_sections::Sections_elements* elements) + : elements_(elements) + { } + + bool + operator()(const Output_section* os1, const Output_section* os2) const; + + private: + int + script_compare(const Output_section* os1, const Output_section* os2) const; + + private: + const Script_sections::Sections_elements* elements_; +}; + +bool +Sort_output_sections::operator()(const Output_section* os1, + const Output_section* os2) const +{ + // Sort first by the load address. + uint64_t lma1 = (os1->has_load_address() + ? os1->load_address() + : os1->address()); + uint64_t lma2 = (os2->has_load_address() + ? os2->load_address() + : os2->address()); + if (lma1 != lma2) + return lma1 < lma2; + + // Then sort by the virtual address. + if (os1->address() != os2->address()) + return os1->address() < os2->address(); + + // If the linker script says which of these sections is first, go + // with what it says. + int i = this->script_compare(os1, os2); + if (i != 0) + return i < 0; + + // Sort PROGBITS before NOBITS. + bool nobits1 = os1->type() == elfcpp::SHT_NOBITS; + bool nobits2 = os2->type() == elfcpp::SHT_NOBITS; + if (nobits1 != nobits2) + return nobits2; + + // Sort PROGBITS TLS sections to the end, NOBITS TLS sections to the + // beginning. + bool tls1 = (os1->flags() & elfcpp::SHF_TLS) != 0; + bool tls2 = (os2->flags() & elfcpp::SHF_TLS) != 0; + if (tls1 != tls2) + return nobits1 ? tls1 : tls2; + + // Sort non-NOLOAD before NOLOAD. + if (os1->is_noload() && !os2->is_noload()) + return true; + if (!os1->is_noload() && os2->is_noload()) + return true; + + // The sections seem practically identical. Sort by name to get a + // stable sort. + return os1->name() < os2->name(); +} + +// Return -1 if OS1 comes before OS2 in ELEMENTS_, 1 if comes after, 0 +// if either OS1 or OS2 is not mentioned. This ensures that we keep +// empty sections in the order in which they appear in a linker +// script. + +int +Sort_output_sections::script_compare(const Output_section* os1, + const Output_section* os2) const +{ + if (this->elements_ == NULL) + return 0; + + bool found_os1 = false; + bool found_os2 = false; + for (Script_sections::Sections_elements::const_iterator + p = this->elements_->begin(); + p != this->elements_->end(); + ++p) + { + if (os2 == (*p)->get_output_section()) + { + if (found_os1) + return -1; + found_os2 = true; + } + else if (os1 == (*p)->get_output_section()) + { + if (found_os2) + return 1; + found_os1 = true; + } + } + + return 0; +} + +// Return whether OS is a BSS section. This is a SHT_NOBITS section. +// We treat a section with the SHF_TLS flag set as taking up space +// even if it is SHT_NOBITS (this is true of .tbss), as we allocate +// space for them in the file. + +bool +Script_sections::is_bss_section(const Output_section* os) +{ + return (os->type() == elfcpp::SHT_NOBITS + && (os->flags() & elfcpp::SHF_TLS) == 0); +} + +// Return the size taken by the file header and the program headers. + +size_t +Script_sections::total_header_size(Layout* layout) const +{ + size_t segment_count = layout->segment_count(); + size_t file_header_size; + size_t segment_headers_size; + if (parameters->target().get_size() == 32) + { + file_header_size = elfcpp::Elf_sizes<32>::ehdr_size; + segment_headers_size = segment_count * elfcpp::Elf_sizes<32>::phdr_size; + } + else if (parameters->target().get_size() == 64) + { + file_header_size = elfcpp::Elf_sizes<64>::ehdr_size; + segment_headers_size = segment_count * elfcpp::Elf_sizes<64>::phdr_size; + } + else + gold_unreachable(); + + return file_header_size + segment_headers_size; +} + +// Return the amount we have to subtract from the LMA to accommodate +// headers of the given size. The complication is that the file +// header have to be at the start of a page, as otherwise it will not +// be at the start of the file. + +uint64_t +Script_sections::header_size_adjustment(uint64_t lma, + size_t sizeof_headers) const +{ + const uint64_t abi_pagesize = parameters->target().abi_pagesize(); + uint64_t hdr_lma = lma - sizeof_headers; + hdr_lma &= ~(abi_pagesize - 1); + return lma - hdr_lma; +} + +// Create the PT_LOAD segments when using a SECTIONS clause. Returns +// the segment which should hold the file header and segment headers, +// if any. + +Output_segment* +Script_sections::create_segments(Layout* layout, uint64_t dot_alignment) +{ + gold_assert(this->saw_sections_clause_); + + if (parameters->options().relocatable()) + return NULL; + + if (this->saw_phdrs_clause()) + return create_segments_from_phdrs_clause(layout, dot_alignment); + + Layout::Section_list sections; + layout->get_allocated_sections(§ions); + + // Sort the sections by address. + std::stable_sort(sections.begin(), sections.end(), + Sort_output_sections(this->sections_elements_)); + + this->create_note_and_tls_segments(layout, §ions); + + // Walk through the sections adding them to PT_LOAD segments. + const uint64_t abi_pagesize = parameters->target().abi_pagesize(); + Output_segment* first_seg = NULL; + Output_segment* current_seg = NULL; + bool is_current_seg_readonly = true; + Layout::Section_list::iterator plast = sections.end(); + uint64_t last_vma = 0; + uint64_t last_lma = 0; + uint64_t last_size = 0; + for (Layout::Section_list::iterator p = sections.begin(); + p != sections.end(); + ++p) + { + const uint64_t vma = (*p)->address(); + const uint64_t lma = ((*p)->has_load_address() + ? (*p)->load_address() + : vma); + const uint64_t size = (*p)->current_data_size(); + + bool need_new_segment; + if (current_seg == NULL) + need_new_segment = true; + else if (lma - vma != last_lma - last_vma) + { + // This section has a different LMA relationship than the + // last one; we need a new segment. + need_new_segment = true; + } + else if (align_address(last_lma + last_size, abi_pagesize) + < align_address(lma, abi_pagesize)) + { + // Putting this section in the segment would require + // skipping a page. + need_new_segment = true; + } + else if (is_bss_section(*plast) && !is_bss_section(*p)) + { + // A non-BSS section can not follow a BSS section in the + // same segment. + need_new_segment = true; + } + else if (is_current_seg_readonly + && ((*p)->flags() & elfcpp::SHF_WRITE) != 0 + && !parameters->options().omagic()) + { + // Don't put a writable section in the same segment as a + // non-writable section. + need_new_segment = true; + } + else + { + // Otherwise, reuse the existing segment. + need_new_segment = false; + } + + elfcpp::Elf_Word seg_flags = + Layout::section_flags_to_segment((*p)->flags()); + + if (need_new_segment) + { + current_seg = layout->make_output_segment(elfcpp::PT_LOAD, + seg_flags); + current_seg->set_addresses(vma, lma); + current_seg->set_minimum_p_align(dot_alignment); + if (first_seg == NULL) + first_seg = current_seg; + is_current_seg_readonly = true; + } + + current_seg->add_output_section_to_load(layout, *p, seg_flags); + + if (((*p)->flags() & elfcpp::SHF_WRITE) != 0) + is_current_seg_readonly = false; + + plast = p; + last_vma = vma; + last_lma = lma; + last_size = size; + } + + // An ELF program should work even if the program headers are not in + // a PT_LOAD segment. However, it appears that the Linux kernel + // does not set the AT_PHDR auxiliary entry in that case. It sets + // the load address to p_vaddr - p_offset of the first PT_LOAD + // segment. It then sets AT_PHDR to the load address plus the + // offset to the program headers, e_phoff in the file header. This + // fails when the program headers appear in the file before the + // first PT_LOAD segment. Therefore, we always create a PT_LOAD + // segment to hold the file header and the program headers. This is + // effectively what the GNU linker does, and it is slightly more + // efficient in any case. We try to use the first PT_LOAD segment + // if we can, otherwise we make a new one. + + if (first_seg == NULL) + return NULL; + + // -n or -N mean that the program is not demand paged and there is + // no need to put the program headers in a PT_LOAD segment. + if (parameters->options().nmagic() || parameters->options().omagic()) + return NULL; + + size_t sizeof_headers = this->total_header_size(layout); + + uint64_t vma = first_seg->vaddr(); + uint64_t lma = first_seg->paddr(); + + uint64_t subtract = this->header_size_adjustment(lma, sizeof_headers); + + if ((lma & (abi_pagesize - 1)) >= sizeof_headers) + { + first_seg->set_addresses(vma - subtract, lma - subtract); + return first_seg; + } + + // If there is no room to squeeze in the headers, then punt. The + // resulting executable probably won't run on GNU/Linux, but we + // trust that the user knows what they are doing. + if (lma < subtract || vma < subtract) + return NULL; + + // If memory regions have been specified and the address range + // we are about to use is not contained within any region then + // issue a warning message about the segment we are going to + // create. It will be outside of any region and so possibly + // using non-existent or protected memory. We test LMA rather + // than VMA since we assume that the headers will never be + // relocated. + if (this->memory_regions_ != NULL + && !this->block_in_region (NULL, layout, lma - subtract, subtract)) + gold_warning(_("creating a segment to contain the file and program" + " headers outside of any MEMORY region")); + + Output_segment* load_seg = layout->make_output_segment(elfcpp::PT_LOAD, + elfcpp::PF_R); + load_seg->set_addresses(vma - subtract, lma - subtract); + + return load_seg; +} + +// Create a PT_NOTE segment for each SHT_NOTE section and a PT_TLS +// segment if there are any SHT_TLS sections. + +void +Script_sections::create_note_and_tls_segments( + Layout* layout, + const Layout::Section_list* sections) +{ + gold_assert(!this->saw_phdrs_clause()); + + bool saw_tls = false; + for (Layout::Section_list::const_iterator p = sections->begin(); + p != sections->end(); + ++p) + { + if ((*p)->type() == elfcpp::SHT_NOTE) + { + elfcpp::Elf_Word seg_flags = + Layout::section_flags_to_segment((*p)->flags()); + Output_segment* oseg = layout->make_output_segment(elfcpp::PT_NOTE, + seg_flags); + oseg->add_output_section_to_nonload(*p, seg_flags); + + // Incorporate any subsequent SHT_NOTE sections, in the + // hopes that the script is sensible. + Layout::Section_list::const_iterator pnext = p + 1; + while (pnext != sections->end() + && (*pnext)->type() == elfcpp::SHT_NOTE) + { + seg_flags = Layout::section_flags_to_segment((*pnext)->flags()); + oseg->add_output_section_to_nonload(*pnext, seg_flags); + p = pnext; + ++pnext; + } + } + + if (((*p)->flags() & elfcpp::SHF_TLS) != 0) + { + if (saw_tls) + gold_error(_("TLS sections are not adjacent")); + + elfcpp::Elf_Word seg_flags = + Layout::section_flags_to_segment((*p)->flags()); + Output_segment* oseg = layout->make_output_segment(elfcpp::PT_TLS, + seg_flags); + oseg->add_output_section_to_nonload(*p, seg_flags); + + Layout::Section_list::const_iterator pnext = p + 1; + while (pnext != sections->end() + && ((*pnext)->flags() & elfcpp::SHF_TLS) != 0) + { + seg_flags = Layout::section_flags_to_segment((*pnext)->flags()); + oseg->add_output_section_to_nonload(*pnext, seg_flags); + p = pnext; + ++pnext; + } + + saw_tls = true; + } + + // If we are making a shared library, and we see a section named + // .interp then put the .interp section in a PT_INTERP segment. + // This is for GNU ld compatibility. + if (strcmp((*p)->name(), ".interp") == 0) + { + elfcpp::Elf_Word seg_flags = + Layout::section_flags_to_segment((*p)->flags()); + Output_segment* oseg = layout->make_output_segment(elfcpp::PT_INTERP, + seg_flags); + oseg->add_output_section_to_nonload(*p, seg_flags); + } + } +} + +// Add a program header. The PHDRS clause is syntactically distinct +// from the SECTIONS clause, but we implement it with the SECTIONS +// support because PHDRS is useless if there is no SECTIONS clause. + +void +Script_sections::add_phdr(const char* name, size_t namelen, unsigned int type, + bool includes_filehdr, bool includes_phdrs, + bool is_flags_valid, unsigned int flags, + Expression* load_address) +{ + if (this->phdrs_elements_ == NULL) + this->phdrs_elements_ = new Phdrs_elements(); + this->phdrs_elements_->push_back(new Phdrs_element(name, namelen, type, + includes_filehdr, + includes_phdrs, + is_flags_valid, flags, + load_address)); +} + +// Return the number of segments we expect to create based on the +// SECTIONS clause. This is used to implement SIZEOF_HEADERS. + +size_t +Script_sections::expected_segment_count(const Layout* layout) const +{ + if (this->saw_phdrs_clause()) + return this->phdrs_elements_->size(); + + Layout::Section_list sections; + layout->get_allocated_sections(§ions); + + // We assume that we will need two PT_LOAD segments. + size_t ret = 2; + + bool saw_note = false; + bool saw_tls = false; + for (Layout::Section_list::const_iterator p = sections.begin(); + p != sections.end(); + ++p) + { + if ((*p)->type() == elfcpp::SHT_NOTE) + { + // Assume that all note sections will fit into a single + // PT_NOTE segment. + if (!saw_note) + { + ++ret; + saw_note = true; + } + } + else if (((*p)->flags() & elfcpp::SHF_TLS) != 0) + { + // There can only be one PT_TLS segment. + if (!saw_tls) + { + ++ret; + saw_tls = true; + } + } + } + + return ret; +} + +// Create the segments from a PHDRS clause. Return the segment which +// should hold the file header and program headers, if any. + +Output_segment* +Script_sections::create_segments_from_phdrs_clause(Layout* layout, + uint64_t dot_alignment) +{ + this->attach_sections_using_phdrs_clause(layout); + return this->set_phdrs_clause_addresses(layout, dot_alignment); +} + +// Create the segments from the PHDRS clause, and put the output +// sections in them. + +void +Script_sections::attach_sections_using_phdrs_clause(Layout* layout) +{ + typedef std::map<std::string, Output_segment*> Name_to_segment; + Name_to_segment name_to_segment; + for (Phdrs_elements::const_iterator p = this->phdrs_elements_->begin(); + p != this->phdrs_elements_->end(); + ++p) + name_to_segment[(*p)->name()] = (*p)->create_segment(layout); + + // Walk through the output sections and attach them to segments. + // Output sections in the script which do not list segments are + // attached to the same set of segments as the immediately preceding + // output section. + + String_list* phdr_names = NULL; + bool load_segments_only = false; + for (Sections_elements::const_iterator p = this->sections_elements_->begin(); + p != this->sections_elements_->end(); + ++p) + { + bool is_orphan; + String_list* old_phdr_names = phdr_names; + Output_section* os = (*p)->allocate_to_segment(&phdr_names, &is_orphan); + if (os == NULL) + continue; + + elfcpp::Elf_Word seg_flags = + Layout::section_flags_to_segment(os->flags()); + + if (phdr_names == NULL) + { + // Don't worry about empty orphan sections. + if (is_orphan && os->current_data_size() > 0) + gold_error(_("allocated section %s not in any segment"), + os->name()); + + // To avoid later crashes drop this section into the first + // PT_LOAD segment. + for (Phdrs_elements::const_iterator ppe = + this->phdrs_elements_->begin(); + ppe != this->phdrs_elements_->end(); + ++ppe) + { + Output_segment* oseg = (*ppe)->segment(); + if (oseg->type() == elfcpp::PT_LOAD) + { + oseg->add_output_section_to_load(layout, os, seg_flags); + break; + } + } + + continue; + } + + // We see a list of segments names. Disable PT_LOAD segment only + // filtering. + if (old_phdr_names != phdr_names) + load_segments_only = false; + + // If this is an orphan section--one that was not explicitly + // mentioned in the linker script--then it should not inherit + // any segment type other than PT_LOAD. Otherwise, e.g., the + // PT_INTERP segment will pick up following orphan sections, + // which does not make sense. If this is not an orphan section, + // we trust the linker script. + if (is_orphan) + { + // Enable PT_LOAD segments only filtering until we see another + // list of segment names. + load_segments_only = true; + } + + bool in_load_segment = false; + for (String_list::const_iterator q = phdr_names->begin(); + q != phdr_names->end(); + ++q) + { + Name_to_segment::const_iterator r = name_to_segment.find(*q); + if (r == name_to_segment.end()) + gold_error(_("no segment %s"), q->c_str()); + else + { + if (load_segments_only + && r->second->type() != elfcpp::PT_LOAD) + continue; + + if (r->second->type() != elfcpp::PT_LOAD) + r->second->add_output_section_to_nonload(os, seg_flags); + else + { + r->second->add_output_section_to_load(layout, os, seg_flags); + if (in_load_segment) + gold_error(_("section in two PT_LOAD segments")); + in_load_segment = true; + } + } + } + + if (!in_load_segment) + gold_error(_("allocated section not in any PT_LOAD segment")); + } +} + +// Set the addresses for segments created from a PHDRS clause. Return +// the segment which should hold the file header and program headers, +// if any. + +Output_segment* +Script_sections::set_phdrs_clause_addresses(Layout* layout, + uint64_t dot_alignment) +{ + Output_segment* load_seg = NULL; + for (Phdrs_elements::const_iterator p = this->phdrs_elements_->begin(); + p != this->phdrs_elements_->end(); + ++p) + { + // Note that we have to set the flags after adding the output + // sections to the segment, as adding an output segment can + // change the flags. + (*p)->set_flags_if_valid(); + + Output_segment* oseg = (*p)->segment(); + + if (oseg->type() != elfcpp::PT_LOAD) + { + // The addresses of non-PT_LOAD segments are set from the + // PT_LOAD segments. + if ((*p)->has_load_address()) + gold_error(_("may only specify load address for PT_LOAD segment")); + continue; + } + + oseg->set_minimum_p_align(dot_alignment); + + // The output sections should have addresses from the SECTIONS + // clause. The addresses don't have to be in order, so find the + // one with the lowest load address. Use that to set the + // address of the segment. + + Output_section* osec = oseg->section_with_lowest_load_address(); + if (osec == NULL) + { + oseg->set_addresses(0, 0); + continue; + } + + uint64_t vma = osec->address(); + uint64_t lma = osec->has_load_address() ? osec->load_address() : vma; + + // Override the load address of the section with the load + // address specified for the segment. + if ((*p)->has_load_address()) + { + if (osec->has_load_address()) + gold_warning(_("PHDRS load address overrides " + "section %s load address"), + osec->name()); + + lma = (*p)->load_address(); + } + + bool headers = (*p)->includes_filehdr() && (*p)->includes_phdrs(); + if (!headers && ((*p)->includes_filehdr() || (*p)->includes_phdrs())) + { + // We could support this if we wanted to. + gold_error(_("using only one of FILEHDR and PHDRS is " + "not currently supported")); + } + if (headers) + { + size_t sizeof_headers = this->total_header_size(layout); + uint64_t subtract = this->header_size_adjustment(lma, + sizeof_headers); + if (lma >= subtract && vma >= subtract) + { + lma -= subtract; + vma -= subtract; + } + else + { + gold_error(_("sections loaded on first page without room " + "for file and program headers " + "are not supported")); + } + + if (load_seg != NULL) + gold_error(_("using FILEHDR and PHDRS on more than one " + "PT_LOAD segment is not currently supported")); + load_seg = oseg; + } + + oseg->set_addresses(vma, lma); + } + + return load_seg; +} + +// Add the file header and segment headers to non-load segments +// specified in the PHDRS clause. + +void +Script_sections::put_headers_in_phdrs(Output_data* file_header, + Output_data* segment_headers) +{ + gold_assert(this->saw_phdrs_clause()); + for (Phdrs_elements::iterator p = this->phdrs_elements_->begin(); + p != this->phdrs_elements_->end(); + ++p) + { + if ((*p)->type() != elfcpp::PT_LOAD) + { + if ((*p)->includes_phdrs()) + (*p)->segment()->add_initial_output_data(segment_headers); + if ((*p)->includes_filehdr()) + (*p)->segment()->add_initial_output_data(file_header); + } + } +} + +// Look for an output section by name and return the address, the load +// address, the alignment, and the size. This is used when an +// expression refers to an output section which was not actually +// created. This returns true if the section was found, false +// otherwise. + +bool +Script_sections::get_output_section_info(const char* name, uint64_t* address, + uint64_t* load_address, + uint64_t* addralign, + uint64_t* size) const +{ + if (!this->saw_sections_clause_) + return false; + for (Sections_elements::const_iterator p = this->sections_elements_->begin(); + p != this->sections_elements_->end(); + ++p) + if ((*p)->get_output_section_info(name, address, load_address, addralign, + size)) + return true; + return false; +} + +// Release all Output_segments. This remove all pointers to all +// Output_segments. + +void +Script_sections::release_segments() +{ + if (this->saw_phdrs_clause()) + { + for (Phdrs_elements::const_iterator p = this->phdrs_elements_->begin(); + p != this->phdrs_elements_->end(); + ++p) + (*p)->release_segment(); + } +} + +// Print the SECTIONS clause to F for debugging. + +void +Script_sections::print(FILE* f) const +{ + if (this->phdrs_elements_ != NULL) + { + fprintf(f, "PHDRS {\n"); + for (Phdrs_elements::const_iterator p = this->phdrs_elements_->begin(); + p != this->phdrs_elements_->end(); + ++p) + (*p)->print(f); + fprintf(f, "}\n"); + } + + if (this->memory_regions_ != NULL) + { + fprintf(f, "MEMORY {\n"); + for (Memory_regions::const_iterator m = this->memory_regions_->begin(); + m != this->memory_regions_->end(); + ++m) + (*m)->print(f); + fprintf(f, "}\n"); + } + + if (!this->saw_sections_clause_) + return; + + fprintf(f, "SECTIONS {\n"); + + for (Sections_elements::const_iterator p = this->sections_elements_->begin(); + p != this->sections_elements_->end(); + ++p) + (*p)->print(f); + + fprintf(f, "}\n"); +} + +} // End namespace gold. |