X-Git-Url: http://git.efficios.com/?a=blobdiff_plain;f=gold%2Fscript-sections.cc;h=68387dbe9636d0a003fd83a2459c3414e47dab67;hb=030a2e78acf66c5c12e073ec3887a167da7a7195;hp=4891ac7d93c245b633ed898c51ecf76a4b1c4d2d;hpb=c42e122ead58317580cb49a2e0db60fd8e308edd;p=deliverable%2Fbinutils-gdb.git diff --git a/gold/script-sections.cc b/gold/script-sections.cc index 4891ac7d93..68387dbe96 100644 --- a/gold/script-sections.cc +++ b/gold/script-sections.cc @@ -1,6 +1,6 @@ // script-sections.cc -- linker script SECTIONS for gold -// Copyright 2008 Free Software Foundation, Inc. +// Copyright (C) 2008-2020 Free Software Foundation, Inc. // Written by Ian Lance Taylor . // This file is part of gold. @@ -43,6 +43,553 @@ 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 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 + set_address(uint64_t addr, const Symbol_table* symtab, const Layout* layout) + { + uint64_t start = this->start_->eval(symtab, layout, false); + uint64_t len = this->length_->eval(symtab, layout, false); + if (addr < start || addr >= start + len) + gold_error(_("address 0x%llx is not within region %s"), + static_cast(addr), + this->name_.c_str()); + else if (addr < start + this->current_offset_) + gold_error(_("address 0x%llx moves dot backwards in region %s"), + static_cast(addr), + this->name_.c_str()); + this->current_offset_ = addr - start; + } + + 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 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); + + // Update PLACE_LAST_ALLOC. + void + update_last_alloc(Elements_iterator where); + + // 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_LAST_ALLOC, + 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_LAST_ALLOC, NULL); + 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; + + // Remember the last allocated section. Any orphan bss sections + // will be placed after it. + if (os != NULL + && (os->flags() & elfcpp::SHF_ALLOC) != 0) + { + this->places_[PLACE_LAST_ALLOC].location = location; + this->places_[PLACE_LAST_ALLOC].have_location = true; + } + + 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_DATA: + follow = PLACE_RODATA; + if (!this->places_[PLACE_RODATA].have_location) + follow = PLACE_TEXT; + break; + case PLACE_BSS: + follow = PLACE_LAST_ALLOC; + 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; +} + +// Update PLACE_LAST_ALLOC. +void +Orphan_section_placement::update_last_alloc(Elements_iterator elem) +{ + Elements_iterator prev = elem; + --prev; + if (this->places_[PLACE_LAST_ALLOC].have_location + && this->places_[PLACE_LAST_ALLOC].location == prev) + { + this->places_[PLACE_LAST_ALLOC].have_location = true; + this->places_[PLACE_LAST_ALLOC].location = elem; + } +} + +// 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 @@ -54,6 +601,16 @@ class 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 @@ -74,19 +631,21 @@ class Sections_element // section name. This only real implementation is in // Output_section_definition. virtual const char* - output_section_name(const char*, const char*, Output_section***) + output_section_name(const char*, const char*, Output_section***, + Script_sections::Section_type*, bool*, bool) { return NULL; } - // Return whether to place an orphan output section after this - // element. - virtual bool - place_orphan_here(const Output_section *, bool*) const - { return false; } + // 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 - // the expression is an absolute value. + // expression is an absolute value. virtual void - set_section_addresses(Symbol_table*, Layout*, uint64_t*, uint64_t*) + set_section_addresses(Symbol_table*, Layout*, uint64_t*, uint64_t*, + uint64_t*) { } // Check a constraint (ONLY_IF_RO, etc.) on an output section. If @@ -126,6 +685,16 @@ class Sections_element 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; @@ -138,7 +707,7 @@ 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, val, provide, hidden) + : assignment_(name, namelen, false, val, provide, hidden) { } // Add the symbol to the symbol table. @@ -159,9 +728,9 @@ class Sections_element_assignment : public Sections_element // absolute symbols when setting dot. void set_section_addresses(Symbol_table* symtab, Layout* layout, - uint64_t* dot_value, uint64_t*) + uint64_t* dot_value, uint64_t*, uint64_t*) { - this->assignment_.set_if_absolute(symtab, layout, true, *dot_value); + this->assignment_.set_if_absolute(symtab, layout, true, *dot_value, NULL); } // Print for debugging. @@ -194,19 +763,18 @@ class Sections_element_dot_assignment : public Sections_element // We ignore the section of the result because outside of an // output section definition the dot symbol is always considered // to be absolute. - Output_section* dummy; *dot_value = this->val_->eval_with_dot(symtab, layout, true, *dot_value, - NULL, &dummy); + 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* load_address) + uint64_t* dot_value, uint64_t* dot_alignment, + uint64_t* load_address) { - Output_section* dummy; *dot_value = this->val_->eval_with_dot(symtab, layout, false, *dot_value, - NULL, &dummy); + NULL, NULL, dot_alignment, false); *load_address = *dot_value; } @@ -256,7 +824,7 @@ class Output_section_element { public: // A list of input sections. - typedef std::list > Input_section_list; + typedef std::list Input_section_list; Output_section_element() { } @@ -282,14 +850,14 @@ class Output_section_element // 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*) const + match_name(const char*, const char*, bool *) const { return false; } // Set section addresses. This includes applying assignments if the - // the expression is an absolute value. + // expression is an absolute value. virtual void set_section_addresses(Symbol_table*, Layout*, Output_section*, uint64_t, - uint64_t*, Output_section**, std::string*, + uint64_t*, uint64_t*, Output_section**, std::string*, Input_section_list*) { } @@ -325,7 +893,7 @@ class Output_section_element_assignment : public Output_section_element Output_section_element_assignment(const char* name, size_t namelen, Expression* val, bool provide, bool hidden) - : assignment_(name, namelen, val, provide, hidden) + : assignment_(name, namelen, false, val, provide, hidden) { } // Add the symbol to the symbol table. @@ -347,10 +915,12 @@ class Output_section_element_assignment : public Output_section_element // absolute symbols when setting dot. void set_section_addresses(Symbol_table* symtab, Layout* layout, Output_section*, - uint64_t, uint64_t* dot_value, Output_section**, - std::string*, Input_section_list*) + 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); + this->assignment_.set_if_absolute(symtab, layout, true, *dot_value, + *dot_section); } // Print for debugging. @@ -374,20 +944,28 @@ class Output_section_element_dot_assignment : public Output_section_element : 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); + *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, Output_section**, - std::string*, Input_section_list*); + uint64_t, uint64_t* dot_value, uint64_t*, + Output_section** dot_section, std::string*, + Input_section_list*); // Print for debugging. void @@ -411,13 +989,15 @@ Output_section_element_dot_assignment::set_section_addresses( 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_section, dot_alignment, + true); if (next_dot < *dot_value) gold_error(_("dot may not move backward")); if (next_dot > *dot_value && output_section != NULL) @@ -433,6 +1013,7 @@ Output_section_element_dot_assignment::set_section_addresses( 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; } @@ -468,7 +1049,7 @@ class Output_data_expression : public Output_section_data 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), + : Output_section_data(size, 0, true), is_signed_(is_signed), val_(val), symtab_(symtab), layout_(layout), dot_value_(dot_value), dot_section_(dot_section) { } @@ -515,10 +1096,10 @@ Output_data_expression::do_write(Output_file* of) void Output_data_expression::do_write_to_buffer(unsigned char* buf) { - Output_section* dummy; uint64_t val = this->val_->eval_with_dot(this->symtab_, this->layout_, true, this->dot_value_, - this->dot_section_, &dummy); + this->dot_section_, NULL, NULL, + false); if (parameters->target().is_big_endian()) this->endian_write_to_buffer(val, buf); @@ -579,8 +1160,8 @@ class Output_section_element_data : public Output_section_element // Store the value in the section. void set_section_addresses(Symbol_table*, Layout*, Output_section*, uint64_t, - uint64_t* dot_value, Output_section**, std::string*, - Input_section_list*); + uint64_t* dot_value, uint64_t*, Output_section**, + std::string*, Input_section_list*); // Print for debugging. void @@ -604,18 +1185,17 @@ Output_section_element_data::set_section_addresses( Output_section* os, uint64_t, uint64_t* dot_value, + uint64_t*, Output_section** dot_section, std::string*, Input_section_list*) { gold_assert(os != NULL); - os->add_output_section_data(new Output_data_expression(this->size_, - this->is_signed_, - this->val_, - symtab, - layout, - *dot_value, - *dot_section)); + 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_; } @@ -662,14 +1242,14 @@ class Output_section_element_fill : public Output_section_element // 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, 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); + &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. @@ -692,15 +1272,6 @@ class Output_section_element_fill : public Output_section_element Expression* val_; }; -// Return whether STRING contains a wildcard character. This is used -// to speed up matching. - -static inline bool -is_wildcard_string(const std::string& s) -{ - return strpbrk(s.c_str(), "?*[") != NULL; -} - // An input section specification in an output section class Output_section_element_input : public Output_section_element @@ -717,15 +1288,15 @@ class Output_section_element_input : public Output_section_element *dot_section = this->final_dot_section_; } - // See whether we match FILE_NAME and SECTION_NAME as an input - // 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) const; + 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 subalign, uint64_t* dot_value, uint64_t*, Output_section**, std::string* fill, Input_section_list*); @@ -744,7 +1315,7 @@ class Output_section_element_input : public Output_section_element Input_section_pattern(const char* patterna, size_t patternlena, Sort_wildcard sorta) : pattern(patterna, patternlena), - pattern_is_wildcard(is_wildcard_string(this->pattern)), + pattern_is_wildcard(is_wildcard_string(this->pattern.c_str())), sort(sorta) { } }; @@ -811,7 +1382,7 @@ Output_section_element_input::Output_section_element_input( 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_); + this->filename_is_wildcard_ = is_wildcard_string(this->filename_pattern_.c_str()); if (spec->input_sections.exclude != NULL) { @@ -820,7 +1391,7 @@ Output_section_element_input::Output_section_element_input( p != spec->input_sections.exclude->end(); ++p) { - bool is_wildcard = is_wildcard_string(*p); + bool is_wildcard = is_wildcard_string((*p).c_str()); this->filename_exclusions_.push_back(std::make_pair(*p, is_wildcard)); } @@ -872,15 +1443,19 @@ Output_section_element_input::match_file_name(const char* file_name) const return true; } -// See whether we match FILE_NAME and SECTION_NAME. +// 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) const + 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; @@ -901,13 +1476,73 @@ Output_section_element_input::match_name(const char* file_name, // Information we use to sort the input sections. -struct Input_section_info +class Input_section_info { - Relobj* relobj; - unsigned int shndx; - std::string section_name; - uint64_t size; - uint64_t addralign; + 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) + { + if (is_compressed_debug_section(name.c_str())) + this->section_name_ = corresponding_uncompressed_section_name(name); + else + 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. @@ -923,33 +1558,84 @@ class Input_section_sorter operator()(const Input_section_info&, const Input_section_info&) const; private: + static unsigned long + get_init_priority(const char*); + Sort_wildcard filename_sort_; Sort_wildcard section_sort_; }; +// Return a relative priority of the section with the specified NAME +// (a lower value meand a higher priority), or 0 if it should be compared +// with others as strings. +// The implementation of this function is copied from ld/ldlang.c. + +unsigned long +Input_section_sorter::get_init_priority(const char* name) +{ + char* end; + unsigned long init_priority; + + // GCC uses the following section names for the init_priority + // attribute with numerical values 101 and 65535 inclusive. A + // lower value means a higher priority. + // + // 1: .init_array.NNNN/.fini_array.NNNN: Where NNNN is the + // decimal numerical value of the init_priority attribute. + // The order of execution in .init_array is forward and + // .fini_array is backward. + // 2: .ctors.NNNN/.dtors.NNNN: Where NNNN is 65535 minus the + // decimal numerical value of the init_priority attribute. + // The order of execution in .ctors is backward and .dtors + // is forward. + + if (strncmp(name, ".init_array.", 12) == 0 + || strncmp(name, ".fini_array.", 12) == 0) + { + init_priority = strtoul(name + 12, &end, 10); + return *end ? 0 : init_priority; + } + else if (strncmp(name, ".ctors.", 7) == 0 + || strncmp(name, ".dtors.", 7) == 0) + { + init_priority = strtoul(name + 7, &end, 10); + return *end ? 0 : 65535 - init_priority; + } + + return 0; +} + bool Input_section_sorter::operator()(const Input_section_info& isi1, const Input_section_info& isi2) const { + if (this->section_sort_ == SORT_WILDCARD_BY_INIT_PRIORITY) + { + unsigned long ip1 = get_init_priority(isi1.section_name().c_str()); + unsigned long ip2 = get_init_priority(isi2.section_name().c_str()); + if (ip1 != 0 && ip2 != 0 && ip1 != ip2) + return ip1 < ip2; + } 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)) + && isi1.addralign() == isi2.addralign()) + || this->section_sort_ == SORT_WILDCARD_BY_INIT_PRIORITY) { - if (isi1.section_name != isi2.section_name) - return isi1.section_name < isi2.section_name; + 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 (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(); + if (isi1.relobj()->name() != isi2.relobj()->name()) + return (isi1.relobj()->name() < isi2.relobj()->name()); } // Otherwise we leave them in the same order. @@ -963,10 +1649,11 @@ Input_section_sorter::operator()(const Input_section_info& isi1, void Output_section_element_input::set_section_addresses( Symbol_table*, - Layout*, + 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) @@ -974,11 +1661,36 @@ Output_section_element_input::set_section_addresses( // We build a list of sections which match each // Input_section_pattern. + // If none of the patterns specify a sort option, we throw all + // matching input sections into a single bin, in the order we + // find them. Otherwise, we put matching input sections into + // a separate bin for each pattern, and sort each one as + // specified. Thus, an input section spec like this: + // *(.foo .bar) + // will group all .foo and .bar sections in the order seen, + // whereas this: + // *(.foo) *(.bar) + // will group all .foo sections followed by all .bar sections. + // This matches Gnu ld behavior. + + // Things get really weird, though, when you add a sort spec + // on some, but not all, of the patterns, like this: + // *(SORT_BY_NAME(.foo) .bar) + // We do not attempt to match Gnu ld behavior in this case. + typedef std::vector > 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); + size_t bin_count = 1; + bool any_patterns_with_sort = false; + for (size_t i = 0; i < input_pattern_count; ++i) + { + const Input_section_pattern& isp(this->input_section_patterns_[i]); + if (isp.sort != SORT_WILDCARD_NONE) + any_patterns_with_sort = true; + } + if (any_patterns_with_sort) + bin_count = input_pattern_count; + Matching_sections matching_sections(bin_count); // Look through the list of sections for this output section. Add // each one which matches to one of the elements of @@ -987,25 +1699,36 @@ Output_section_element_input::set_section_addresses( 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. - Input_section_info isi; - isi.relobj = p->first; - isi.shndx = p->second; // 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(-1); - Task_lock_obj tl(task, p->first); - - isi.section_name = p->first->section_name(p->second); - isi.size = p->first->section_size(p->second); - isi.addralign = p->first->section_addralign(p->second); + Task_lock_obj 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(isi.relobj->name().c_str())) + if (!this->match_file_name(relobj->name().c_str())) ++p; else if (this->input_section_patterns_.empty()) { @@ -1019,15 +1742,17 @@ Output_section_element_input::set_section_addresses( { const Input_section_pattern& isp(this->input_section_patterns_[i]); - if (match(isi.section_name.c_str(), isp.pattern.c_str(), + if (match(isi.section_name().c_str(), isp.pattern.c_str(), isp.pattern_is_wildcard)) break; } - if (i >= this->input_section_patterns_.size()) + if (i >= input_pattern_count) ++p; else { + if (i >= bin_count) + i = 0; matching_sections[i].push_back(isi); p = input_sections->erase(p); } @@ -1039,7 +1764,8 @@ Output_section_element_input::set_section_addresses( // sections are otherwise equal. Add each input section to the // output section. - for (size_t i = 0; i < input_pattern_count; ++i) + uint64_t dot = *dot_value; + for (size_t i = 0; i < bin_count; ++i) { if (matching_sections[i].empty()) continue; @@ -1059,30 +1785,45 @@ Output_section_element_input::set_section_addresses( p != matching_sections[i].end(); ++p) { - uint64_t this_subalign = p->addralign; - if (this_subalign < subalign) - this_subalign = subalign; + // Override the original address alignment if SUBALIGN is specified. + // 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 (subalign > 0) + { + this_subalign = subalign; + sis.set_addralign(subalign); + } - uint64_t address = align_address(*dot_value, this_subalign); + uint64_t address = align_address(dot, this_subalign); - if (address > *dot_value && !fill->empty()) + if (address > dot && !fill->empty()) { section_size_type length = - convert_to_section_size_type(address - *dot_value); + 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_input_section_for_script(p->relobj, - p->shndx, - p->size, - this_subalign); - - *dot_value = address + p->size; + 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; } @@ -1171,6 +1912,10 @@ Output_section_element_input::print(FILE* f) const fprintf(f, "SORT_BY_ALIGNMENT(SORT_BY_NAME("); close_parens = 2; break; + case SORT_WILDCARD_BY_INIT_PRIORITY: + fprintf(f, "SORT_BY_INIT_PRIORITY("); + close_parens = 1; + break; default: gold_unreachable(); } @@ -1231,6 +1976,16 @@ class Output_section_definition : public Sections_element 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*); @@ -1247,16 +2002,20 @@ class Output_section_definition : public Sections_element // section name. const char* output_section_name(const char* file_name, const char* section_name, - Output_section***); + Output_section***, Script_sections::Section_type*, + bool*, bool); - // Return whether to place an orphan section after this one. - bool - place_orphan_here(const Output_section *os, bool* exact) const; + // 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* load_address); + 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, @@ -1284,11 +2043,39 @@ class Output_section_definition : public Sections_element 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_elements; // The output section name. @@ -1319,6 +2106,10 @@ class Output_section_definition : public Sections_element 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. @@ -1336,7 +2127,12 @@ Output_section_definition::Output_section_definition( fill_(NULL), phdrs_(NULL), elements_(), - output_section_(NULL) + output_section_(NULL), + evaluated_address_(0), + evaluated_load_address_(0), + evaluated_addralign_(0), + is_relro_(false), + script_section_type_(header->section_type) { } @@ -1432,7 +2228,8 @@ Output_section_definition::create_sections(Layout* layout) if ((*p)->needs_output_section()) { const char* name = this->name_.c_str(); - this->output_section_ = layout->make_output_section_for_script(name); + this->output_section_ = + layout->make_output_section_for_script(name, this->section_type()); return; } } @@ -1463,18 +2260,15 @@ Output_section_definition::finalize_symbols(Symbol_table* symtab, uint64_t address = *dot_value; if (this->address_ != NULL) { - Output_section* dummy; address = this->address_->eval_with_dot(symtab, layout, true, *dot_value, NULL, - &dummy); + NULL, NULL, false); } if (this->align_ != NULL) { - Output_section* dummy; uint64_t align = this->align_->eval_with_dot(symtab, layout, true, - *dot_value, - NULL, - &dummy); + *dot_value, NULL, + NULL, NULL, false); address = align_address(address, align); } *dot_value = address; @@ -1490,20 +2284,36 @@ Output_section_definition::finalize_symbols(Symbol_table* symtab, // 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) +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, + bool match_input_spec) { + // If the section is a linker-created output section, just look for a match + // on the output section name. + if (!match_input_spec && this->name_ != "/DISCARD/") + { + if (this->name_ != section_name) + return NULL; + *slot = &this->output_section_; + *psection_type = this->section_type(); + return this->name_.c_str(); + } + // 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)) + 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(); } } @@ -1512,119 +2322,110 @@ Output_section_definition::output_section_name(const char* file_name, return NULL; } -// Return whether to place an orphan output section after this -// section. +// Return true if memory from START to START + LENGTH is contained +// within a memory region. bool -Output_section_definition::place_orphan_here(const Output_section *os, - bool* exact) const +Script_sections::block_in_region(Symbol_table* symtab, Layout* layout, + uint64_t start, uint64_t length) const { - // Check for the simple case first. - if (this->output_section_ != NULL - && this->output_section_->type() == os->type() - && this->output_section_->flags() == os->flags()) - { - *exact = true; - return true; - } - - // Otherwise use some heuristics. - - if ((os->flags() & elfcpp::SHF_ALLOC) == 0) + if (this->memory_regions_ == NULL) return false; - if (os->type() == elfcpp::SHT_NOBITS) + for (Memory_regions::const_iterator mr = this->memory_regions_->begin(); + mr != this->memory_regions_->end(); + ++mr) { - if (this->name_ == ".bss") - { - *exact = true; - return true; - } - if (this->output_section_ != NULL - && this->output_section_->type() == elfcpp::SHT_NOBITS) - return true; - } - else if (os->type() == elfcpp::SHT_NOTE) - { - if (this->output_section_ != NULL - && this->output_section_->type() == elfcpp::SHT_NOTE) - { - *exact = true; - return true; - } - if (this->name_.compare(0, 5, ".note") == 0) - { - *exact = true; - return true; - } - if (this->name_ == ".interp") - return true; - if (this->output_section_ != NULL - && this->output_section_->type() == elfcpp::SHT_PROGBITS - && (this->output_section_->flags() & elfcpp::SHF_WRITE) == 0) - return true; - } - else if (os->type() == elfcpp::SHT_REL || os->type() == elfcpp::SHT_RELA) - { - if (this->name_.compare(0, 4, ".rel") == 0) - { - *exact = true; - return true; - } - if (this->output_section_ != NULL - && (this->output_section_->type() == elfcpp::SHT_REL - || this->output_section_->type() == elfcpp::SHT_RELA)) - { - *exact = true; - return true; - } - if (this->output_section_ != NULL - && this->output_section_->type() == elfcpp::SHT_PROGBITS - && (this->output_section_->flags() & elfcpp::SHF_WRITE) == 0) + 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; } - else if (os->type() == elfcpp::SHT_PROGBITS - && (os->flags() & elfcpp::SHF_WRITE) != 0) + + 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, + bool explicit_only, + 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 (this->name_ == ".data") + if (find_vma_region) { - *exact = true; - return true; + 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; + } } - if (this->output_section_ != NULL - && this->output_section_->type() == elfcpp::SHT_PROGBITS - && (this->output_section_->flags() & elfcpp::SHF_WRITE) != 0) - return true; - } - else if (os->type() == elfcpp::SHT_PROGBITS - && (os->flags() & elfcpp::SHF_EXECINSTR) != 0) - { - if (this->name_ == ".text") + else { - *exact = true; - return true; + 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; + } } - if (this->output_section_ != NULL - && this->output_section_->type() == elfcpp::SHT_PROGBITS - && (this->output_section_->flags() & elfcpp::SHF_EXECINSTR) != 0) - return true; - } - else if (os->type() == elfcpp::SHT_PROGBITS - || (os->type() != elfcpp::SHT_PROGBITS - && (os->flags() & elfcpp::SHF_WRITE) == 0)) - { - if (this->name_ == ".rodata") + + if (!explicit_only) { - *exact = true; - return true; + // 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; } - if (this->output_section_ != NULL - && this->output_section_->type() == elfcpp::SHT_PROGBITS - && (this->output_section_->flags() & elfcpp::SHF_WRITE) == 0) - return true; } - return false; + // 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 @@ -1635,16 +2436,57 @@ 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; - if (this->address_ == NULL) - address = *dot_value; + 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, false, NULL); + if (vma_region != NULL) + address = vma_region->get_current_address()->eval(symtab, layout, + false); + else + address = *dot_value; + } else { - Output_section* dummy; + vma_region = script_sections->find_memory_region(this, true, true, NULL); address = this->address_->eval_with_dot(symtab, layout, true, - *dot_value, NULL, &dummy); + *dot_value, NULL, NULL, + dot_alignment, false); + if (vma_region != NULL) + vma_region->set_address(address, symtab, layout); } uint64_t align; @@ -1659,7 +2501,7 @@ Output_section_definition::set_section_addresses(Symbol_table* symtab, { Output_section* align_section; align = this->align_->eval_with_dot(symtab, layout, true, *dot_value, - NULL, &align_section); + NULL, &align_section, NULL, false); if (align_section != NULL) gold_warning(_("alignment of section %s is not absolute"), this->name_.c_str()); @@ -1667,48 +2509,119 @@ Output_section_definition::set_section_addresses(Symbol_table* symtab, this->output_section_->set_addralign(align); } + 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()); + + // Reserve a value of 0 to mean there is no SUBALIGN property. + if (subalign == 0) + subalign = 1; + + // The external alignment of the output section must be at least + // as large as that of the input sections. If there is no + // explicit ALIGN property, we set the output section alignment + // to match the input section alignment. + if (align < subalign || this->align_ == NULL) + { + align = subalign; + this->output_section_->set_addralign(align); + } + } + address = align_address(address, align); uint64_t start_address = address; *dot_value = address; - // The address of non-SHF_ALLOC sections is forced to zero, - // regardless of what the linker script wants. + // 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_->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) - this->evaluated_load_address_ = address; - else { - Output_section* dummy; - uint64_t load_address = - this->load_address_->eval_with_dot(symtab, layout, true, *dot_value, - this->output_section_, &dummy); - if (this->output_section_ != NULL) - this->output_section_->set_load_address(load_address); - this->evaluated_load_address_ = load_address; - } + Output_section_definition* previous_section; - uint64_t subalign; - if (this->subalign_ == NULL) - subalign = 0; + // Determine if an LMA region has been set for this section. + lma_region = script_sections->find_memory_region(this, false, 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 { - Output_section* subalign_section; - subalign = this->subalign_->eval_with_dot(symtab, layout, true, - *dot_value, NULL, - &subalign_section); - if (subalign_section != NULL) - gold_warning(_("subalign of section %s is not absolute"), - this->name_.c_str()); + 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; + std::string fill; if (this->fill_ != NULL) { @@ -1717,8 +2630,8 @@ Output_section_definition::set_section_addresses(Symbol_table* symtab, Output_section* fill_section; uint64_t fill_val = this->fill_->eval_with_dot(symtab, layout, true, *dot_value, - NULL, - &fill_section); + NULL, &fill_section, + NULL, false); if (fill_section != NULL) gold_warning(_("fill of section %s is not absolute"), this->name_.c_str()); @@ -1744,16 +2657,61 @@ Output_section_definition::set_section_addresses(Symbol_table* symtab, p != this->elements_.end(); ++p) (*p)->set_section_addresses(symtab, layout, this->output_section_, - subalign, dot_value, &dot_section, &fill, - &input_sections); + subalign, dot_value, dot_alignment, + &dot_section, &fill, &input_sections); gold_assert(input_sections.empty()); - if (this->load_address_ == NULL || this->output_section_ == NULL) + 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 @@ -1835,6 +2793,11 @@ Output_section_definition::alternate_constraint( 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; } @@ -1845,13 +2808,16 @@ 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; - if (this->phdrs_ != NULL) - *phdrs_list = this->phdrs_; return this->output_section_; } @@ -1905,6 +2871,10 @@ Output_section_definition::print(FILE* f) const 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) @@ -1954,6 +2924,60 @@ Output_section_definition::print(FILE* f) const 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 @@ -1966,19 +2990,35 @@ class Orphan_output_section : public Sections_element : os_(os) { } - // Return whether to place an orphan section after this one. + // 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 - place_orphan_here(const Output_section *os, bool* exact) const; + 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*); + 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 @@ -1991,35 +3031,41 @@ class Orphan_output_section : public Sections_element Output_section* os_; }; -// Whether to place another orphan section after this one. - -bool -Orphan_output_section::place_orphan_here(const Output_section* os, - bool* exact) const -{ - if (this->os_->type() == os->type() - && this->os_->flags() == os->flags()) - { - *exact = true; - return true; - } - return false; -} - // 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 > Input_section_list; + typedef std::list 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); @@ -2035,30 +3081,33 @@ Orphan_output_section::set_section_addresses(Symbol_table*, Layout*, p != input_sections.end(); ++p) { - uint64_t addralign; - uint64_t size; - - // We know what are single-threaded, so it is OK to lock the - // object. - { - const Task* task = reinterpret_cast(-1); - Task_lock_obj tl(task, p->first); - addralign = p->first->section_addralign(p->second); - size = p->first->section_size(p->second); - } - + 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_input_section_for_script(p->first, p->second, size, - addralign); + this->os_->add_script_input_section(*p); address += size; } - if (!have_load_address) - *load_address = address; - else - *load_address += address - *dot_value; + 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; + *dot_value = address; + } } // Get the list of segments to use for an allocated section when using @@ -2144,6 +3193,11 @@ class Phdrs_element segment() { return this->segment_; } + // Release the segment. + void + release_segment() + { this->segment_ = NULL; } + // Set the segment flags if appropriate. void set_flags_if_valid() @@ -2199,6 +3253,86 @@ Phdrs_element::print(FILE* f) const 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(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() @@ -2206,7 +3340,14 @@ Script_sections::Script_sections() in_sections_clause_(false), sections_elements_(NULL), output_section_(NULL), - phdrs_elements_(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), + segments_created_(false) { } @@ -2259,6 +3400,15 @@ Script_sections::add_dot_assignment(Expression* val) 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); } @@ -2286,7 +3436,7 @@ void Script_sections::start_output_section( const char* name, size_t namelen, - const Parser_output_section_header *header) + const Parser_output_section_header* header) { Output_section_definition* posd = new Output_section_definition(name, namelen, @@ -2334,6 +3484,42 @@ Script_sections::add_input_section(const Input_section_spec* spec, bool keep) 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 @@ -2378,16 +3564,22 @@ Script_sections::finalize_symbols(Symbol_table* symtab, const Layout* layout) // 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::output_section_name( + const char* file_name, + const char* section_name, + Output_section*** output_section_slot, + Script_sections::Section_type* psection_type, + bool* keep, + bool is_input_section) { 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); + output_section_slot, + psection_type, keep, + is_input_section); if (ret != NULL) { @@ -2396,17 +3588,44 @@ Script_sections::output_section_name(const char* file_name, 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. - + // We have an orphan section. *output_section_slot = NULL; + *psection_type = Script_sections::ST_NONE; + *keep = false; + + General_options::Orphan_handling orphan_handling = + parameters->options().orphan_handling_enum(); + if (orphan_handling == General_options::ORPHAN_DISCARD) + return NULL; + if (orphan_handling == General_options::ORPHAN_ERROR) + { + if (file_name == NULL) + gold_error(_("unplaced orphan section '%s'"), section_name); + else + gold_error(_("unplaced orphan section '%s' from '%s'"), + section_name, file_name); + return NULL; + } + if (orphan_handling == General_options::ORPHAN_WARN) + { + if (file_name == NULL) + gold_warning(_("orphan section '%s' is being placed in section '%s'"), + section_name, section_name); + else + gold_warning(_("orphan section '%s' from '%s' is being placed " + "in section '%s'"), + section_name, file_name, section_name); + } + // If we couldn't find a mapping for the name, the output section + // gets the name of the input section. return section_name; } @@ -2416,27 +3635,52 @@ Script_sections::output_section_name(const char* file_name, void Script_sections::place_orphan(Output_section* os) { - // Look for an output section definition which matches the output - // section. Put a marker after that section. - Sections_elements::iterator place = this->sections_elements_->end(); - for (Sections_elements::iterator p = this->sections_elements_->begin(); - p != this->sections_elements_->end(); - ++p) + Orphan_section_placement* osp = this->orphan_section_placement_; + if (osp == NULL) { - bool exact = false; - if ((*p)->place_orphan_here(os, &exact)) - { - place = p; - if (exact) - break; - } + // 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; } - // The insert function puts the new element before the iterator. - if (place != this->sections_elements_->end()) - ++place; + 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); + } - this->sections_elements_->insert(place, new Orphan_output_section(os)); + if ((os->flags() & elfcpp::SHF_ALLOC) != 0) + osp->update_last_alloc(*where); } // Set the addresses of all the output sections. Walk through all the @@ -2479,13 +3723,77 @@ Script_sections::set_section_addresses(Symbol_table* symtab, Layout* layout) } } + // 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) - (*p)->set_section_addresses(symtab, layout, &dot_value, &load_address); + { + 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) { @@ -2495,7 +3803,7 @@ Script_sections::set_section_addresses(Symbol_table* symtab, Layout* layout) (*p)->eval_load_address(symtab, layout); } - return this->create_segments(layout); + return this->create_segments(layout, dot_alignment); } // Sort the sections in order to put them into segments. @@ -2503,8 +3811,19 @@ Script_sections::set_section_addresses(Symbol_table* symtab, Layout* layout) 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 @@ -2525,20 +3844,70 @@ Sort_output_sections::operator()(const Output_section* os1, if (os1->address() != os2->address()) return os1->address() < os2->address(); - // Sort TLS sections to the end. + // 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 tls2; + return nobits1 ? tls1 : tls2; - // Sort PROGBITS before NOBITS. - if (os1->type() == elfcpp::SHT_PROGBITS && os2->type() == elfcpp::SHT_NOBITS) + // Sort non-NOLOAD before NOLOAD. + if (os1->is_noload() && !os2->is_noload()) + return true; + if (!os1->is_noload() && os2->is_noload()) return true; - if (os1->type() == elfcpp::SHT_NOBITS && os2->type() == elfcpp::SHT_PROGBITS) - return false; - // Otherwise we don't care. - return false; + // 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. @@ -2577,7 +3946,7 @@ Script_sections::total_header_size(Layout* layout) const return file_header_size + segment_headers_size; } -// Return the amount we have to subtract from the LMA to accomodate +// 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. @@ -2597,7 +3966,7 @@ Script_sections::header_size_adjustment(uint64_t lma, // if any. Output_segment* -Script_sections::create_segments(Layout* layout) +Script_sections::create_segments(Layout* layout, uint64_t dot_alignment) { gold_assert(this->saw_sections_clause_); @@ -2605,13 +3974,14 @@ Script_sections::create_segments(Layout* layout) return NULL; if (this->saw_phdrs_clause()) - return create_segments_from_phdrs_clause(layout); + 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()); + std::stable_sort(sections.begin(), sections.end(), + Sort_output_sections(this->sections_elements_)); this->create_note_and_tls_segments(layout, §ions); @@ -2620,10 +3990,10 @@ Script_sections::create_segments(Layout* layout) 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; + bool in_bss = false; for (Layout::Section_list::iterator p = sections.begin(); p != sections.end(); ++p) @@ -2650,14 +4020,15 @@ Script_sections::create_segments(Layout* layout) // skipping a page. need_new_segment = true; } - else if (is_bss_section(*plast) && !is_bss_section(*p)) + else if (in_bss && !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) + && ((*p)->flags() & elfcpp::SHF_WRITE) != 0 + && !parameters->options().omagic()) { // Don't put a writable section in the same segment as a // non-writable section. @@ -2677,17 +4048,21 @@ Script_sections::create_segments(Layout* layout) 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; + in_bss = false; } - current_seg->add_output_section(*p, seg_flags); + 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; + if (is_bss_section(*p) && size > 0) + in_bss = true; + last_vma = vma; last_lma = lma; last_size = size; @@ -2709,6 +4084,11 @@ Script_sections::create_segments(Layout* layout) 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(); @@ -2728,6 +4108,18 @@ Script_sections::create_segments(Layout* layout) 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); @@ -2756,7 +4148,7 @@ Script_sections::create_note_and_tls_segments( Layout::section_flags_to_segment((*p)->flags()); Output_segment* oseg = layout->make_output_segment(elfcpp::PT_NOTE, seg_flags); - oseg->add_output_section(*p, 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. @@ -2765,7 +4157,7 @@ Script_sections::create_note_and_tls_segments( && (*pnext)->type() == elfcpp::SHT_NOTE) { seg_flags = Layout::section_flags_to_segment((*pnext)->flags()); - oseg->add_output_section(*pnext, seg_flags); + oseg->add_output_section_to_nonload(*pnext, seg_flags); p = pnext; ++pnext; } @@ -2780,26 +4172,40 @@ Script_sections::create_note_and_tls_segments( Layout::section_flags_to_segment((*p)->flags()); Output_segment* oseg = layout->make_output_segment(elfcpp::PT_TLS, seg_flags); - oseg->add_output_section(*p, 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(*pnext, seg_flags); + oseg->add_output_section_to_nonload(*pnext, seg_flags); p = pnext; ++pnext; } saw_tls = true; } + + // If 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); + } } + + this->segments_created_ = true; } // Add a program header. The PHDRS clause is syntactically distinct // from the SECTIONS clause, but we implement it with the SECTIONS -// support becauase PHDRS is useless if there is no SECTIONS clause. +// 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, @@ -2822,6 +4228,10 @@ Script_sections::add_phdr(const char* name, size_t namelen, unsigned int type, size_t Script_sections::expected_segment_count(const Layout* layout) const { + // If we've already created the segments, we won't be adding any more. + if (this->segments_created_) + return 0; + if (this->saw_phdrs_clause()) return this->phdrs_elements_->size(); @@ -2833,6 +4243,7 @@ Script_sections::expected_segment_count(const Layout* layout) const bool saw_note = false; bool saw_tls = false; + bool saw_interp = false; for (Layout::Section_list::const_iterator p = sections.begin(); p != sections.end(); ++p) @@ -2856,6 +4267,15 @@ Script_sections::expected_segment_count(const Layout* layout) const saw_tls = true; } } + else if (strcmp((*p)->name(), ".interp") == 0) + { + // There can only be one PT_INTERP segment. + if (!saw_interp) + { + ++ret; + saw_interp = true; + } + } } return ret; @@ -2865,10 +4285,11 @@ Script_sections::expected_segment_count(const Layout* layout) const // should hold the file header and program headers, if any. Output_segment* -Script_sections::create_segments_from_phdrs_clause(Layout* layout) +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); + return this->set_phdrs_clause_addresses(layout, dot_alignment); } // Create the segments from the PHDRS clause, and put the output @@ -2883,46 +4304,69 @@ Script_sections::attach_sections_using_phdrs_clause(Layout* layout) p != this->phdrs_elements_->end(); ++p) name_to_segment[(*p)->name()] = (*p)->create_segment(layout); + this->segments_created_ = true; // 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 orphan; - Output_section* os = (*p)->allocate_to_segment(&phdr_names, &orphan); + 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) { - gold_error(_("allocated section not in any segment")); + // 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 (orphan) + if (is_orphan) { - String_list::iterator q = phdr_names->begin(); - while (q != phdr_names->end()) - { - Name_to_segment::const_iterator r = name_to_segment.find(*q); - // We give errors about unknown segments below. - if (r == name_to_segment.end() - || r->second->type() == elfcpp::PT_LOAD) - ++q; - else - q = phdr_names->erase(q); - } + // Enable PT_LOAD segments only filtering until we see another + // list of segment names. + load_segments_only = true; } bool in_load_segment = false; @@ -2935,12 +4379,15 @@ Script_sections::attach_sections_using_phdrs_clause(Layout* layout) gold_error(_("no segment %s"), q->c_str()); else { - elfcpp::Elf_Word seg_flags = - Layout::section_flags_to_segment(os->flags()); - r->second->add_output_section(os, seg_flags); + if (load_segments_only + && r->second->type() != elfcpp::PT_LOAD) + continue; - if (r->second->type() == elfcpp::PT_LOAD) + 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; @@ -2958,7 +4405,8 @@ Script_sections::attach_sections_using_phdrs_clause(Layout* layout) // if any. Output_segment* -Script_sections::set_phdrs_clause_addresses(Layout* layout) +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(); @@ -2981,6 +4429,8 @@ Script_sections::set_phdrs_clause_addresses(Layout* layout) 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 @@ -3089,11 +4539,47 @@ Script_sections::get_output_section_info(const char* name, uint64_t* address, 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(); + } + this->segments_created_ = false; +} + // 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; @@ -3105,16 +4591,6 @@ Script_sections::print(FILE* f) const (*p)->print(f); fprintf(f, "}\n"); - - 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"); - } } } // End namespace gold.