// script-sections.cc -- linker script SECTIONS for gold
-// Copyright 2008 Free Software Foundation, Inc.
+// Copyright 2008, 2009 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
#include "gold.h"
+#include <cstring>
+#include <algorithm>
+#include <list>
+#include <map>
#include <string>
#include <vector>
+#include <fnmatch.h>
+#include "parameters.h"
+#include "object.h"
+#include "layout.h"
+#include "output.h"
#include "script-c.h"
#include "script.h"
#include "script-sections.h"
namespace gold
{
+// Manage orphan sections. This is intended to be largely compatible
+// with the GNU linker. The Linux kernel implicitly relies on
+// something similar to the GNU linker's orphan placement. We
+// originally used a simpler scheme here, but it caused the kernel
+// build to fail, and was also rather inefficient.
+
+class Orphan_section_placement
+{
+ private:
+ typedef Script_sections::Elements_iterator Elements_iterator;
+
+ public:
+ Orphan_section_placement();
+
+ // Handle an output section during initialization of this mapping.
+ void
+ output_section_init(const std::string& name, Output_section*,
+ Elements_iterator location);
+
+ // Initialize the last location.
+ void
+ last_init(Elements_iterator location);
+
+ // Set *PWHERE to the address of an iterator pointing to the
+ // location to use for an orphan section. Return true if the
+ // iterator has a value, false otherwise.
+ bool
+ find_place(Output_section*, Elements_iterator** pwhere);
+
+ // Return the iterator being used for sections at the very end of
+ // the linker script.
+ Elements_iterator
+ last_place() const;
+
+ private:
+ // The places that we specifically recognize. This list is copied
+ // from the GNU linker.
+ enum Place_index
+ {
+ PLACE_TEXT,
+ PLACE_RODATA,
+ PLACE_DATA,
+ PLACE_BSS,
+ PLACE_REL,
+ PLACE_INTERP,
+ PLACE_NONALLOC,
+ PLACE_LAST,
+ PLACE_MAX
+ };
+
+ // The information we keep for a specific place.
+ struct Place
+ {
+ // The name of sections for this place.
+ const char* name;
+ // Whether we have a location for this place.
+ bool have_location;
+ // The iterator for this place.
+ Elements_iterator location;
+ };
+
+ // Initialize one place element.
+ void
+ initialize_place(Place_index, const char*);
+
+ // The places.
+ Place places_[PLACE_MAX];
+ // True if this is the first call to output_section_init.
+ bool first_init_;
+};
+
+// Initialize Orphan_section_placement.
+
+Orphan_section_placement::Orphan_section_placement()
+ : first_init_(true)
+{
+ this->initialize_place(PLACE_TEXT, ".text");
+ this->initialize_place(PLACE_RODATA, ".rodata");
+ this->initialize_place(PLACE_DATA, ".data");
+ this->initialize_place(PLACE_BSS, ".bss");
+ this->initialize_place(PLACE_REL, NULL);
+ this->initialize_place(PLACE_INTERP, ".interp");
+ this->initialize_place(PLACE_NONALLOC, NULL);
+ this->initialize_place(PLACE_LAST, NULL);
+}
+
+// Initialize one place element.
+
+void
+Orphan_section_placement::initialize_place(Place_index index, const char* name)
+{
+ this->places_[index].name = name;
+ this->places_[index].have_location = false;
+}
+
+// While initializing the Orphan_section_placement information, this
+// is called once for each output section named in the linker script.
+// If we found an output section during the link, it will be passed in
+// OS.
+
+void
+Orphan_section_placement::output_section_init(const std::string& name,
+ Output_section* os,
+ Elements_iterator location)
+{
+ bool first_init = this->first_init_;
+ this->first_init_ = false;
+
+ for (int i = 0; i < PLACE_MAX; ++i)
+ {
+ if (this->places_[i].name != NULL && this->places_[i].name == name)
+ {
+ if (this->places_[i].have_location)
+ {
+ // We have already seen a section with this name.
+ return;
+ }
+
+ this->places_[i].location = location;
+ this->places_[i].have_location = true;
+
+ // If we just found the .bss section, restart the search for
+ // an unallocated section. This follows the GNU linker's
+ // behaviour.
+ if (i == PLACE_BSS)
+ this->places_[PLACE_NONALLOC].have_location = false;
+
+ return;
+ }
+ }
+
+ // Relocation sections.
+ if (!this->places_[PLACE_REL].have_location
+ && os != NULL
+ && (os->type() == elfcpp::SHT_REL || os->type() == elfcpp::SHT_RELA)
+ && (os->flags() & elfcpp::SHF_ALLOC) != 0)
+ {
+ this->places_[PLACE_REL].location = location;
+ this->places_[PLACE_REL].have_location = true;
+ }
+
+ // We find the location for unallocated sections by finding the
+ // first debugging or comment section after the BSS section (if
+ // there is one).
+ if (!this->places_[PLACE_NONALLOC].have_location
+ && (name == ".comment" || Layout::is_debug_info_section(name.c_str())))
+ {
+ // We add orphan sections after the location in PLACES_. We
+ // want to store unallocated sections before LOCATION. If this
+ // is the very first section, we can't use it.
+ if (!first_init)
+ {
+ --location;
+ this->places_[PLACE_NONALLOC].location = location;
+ this->places_[PLACE_NONALLOC].have_location = true;
+ }
+ }
+}
+
+// Initialize the last location.
+
+void
+Orphan_section_placement::last_init(Elements_iterator location)
+{
+ this->places_[PLACE_LAST].location = location;
+ this->places_[PLACE_LAST].have_location = true;
+}
+
+// Set *PWHERE to the address of an iterator pointing to the location
+// to use for an orphan section. Return true if the iterator has a
+// value, false otherwise.
+
+bool
+Orphan_section_placement::find_place(Output_section* os,
+ Elements_iterator** pwhere)
+{
+ // Figure out where OS should go. This is based on the GNU linker
+ // code. FIXME: The GNU linker handles small data sections
+ // specially, but we don't.
+ elfcpp::Elf_Word type = os->type();
+ elfcpp::Elf_Xword flags = os->flags();
+ Place_index index;
+ if ((flags & elfcpp::SHF_ALLOC) == 0
+ && !Layout::is_debug_info_section(os->name()))
+ index = PLACE_NONALLOC;
+ else if ((flags & elfcpp::SHF_ALLOC) == 0)
+ index = PLACE_LAST;
+ else if (type == elfcpp::SHT_NOTE)
+ index = PLACE_INTERP;
+ else if (type == elfcpp::SHT_NOBITS)
+ index = PLACE_BSS;
+ else if ((flags & elfcpp::SHF_WRITE) != 0)
+ index = PLACE_DATA;
+ else if (type == elfcpp::SHT_REL || type == elfcpp::SHT_RELA)
+ index = PLACE_REL;
+ else if ((flags & elfcpp::SHF_EXECINSTR) == 0)
+ index = PLACE_RODATA;
+ else
+ index = PLACE_TEXT;
+
+ // If we don't have a location yet, try to find one based on a
+ // plausible ordering of sections.
+ if (!this->places_[index].have_location)
+ {
+ Place_index follow;
+ switch (index)
+ {
+ default:
+ follow = PLACE_MAX;
+ break;
+ case PLACE_RODATA:
+ follow = PLACE_TEXT;
+ break;
+ case PLACE_BSS:
+ follow = PLACE_DATA;
+ break;
+ case PLACE_REL:
+ follow = PLACE_TEXT;
+ break;
+ case PLACE_INTERP:
+ follow = PLACE_TEXT;
+ break;
+ }
+ if (follow != PLACE_MAX && this->places_[follow].have_location)
+ {
+ // Set the location of INDEX to the location of FOLLOW. The
+ // location of INDEX will then be incremented by the caller,
+ // so anything in INDEX will continue to be after anything
+ // in FOLLOW.
+ this->places_[index].location = this->places_[follow].location;
+ this->places_[index].have_location = true;
+ }
+ }
+
+ *pwhere = &this->places_[index].location;
+ bool ret = this->places_[index].have_location;
+
+ // The caller will set the location.
+ this->places_[index].have_location = true;
+
+ return ret;
+}
+
+// Return the iterator being used for sections at the very end of the
+// linker script.
+
+Orphan_section_placement::Elements_iterator
+Orphan_section_placement::last_place() const
+{
+ gold_assert(this->places_[PLACE_LAST].have_location);
+ return this->places_[PLACE_LAST].location;
+}
+
// An element in a SECTIONS clause.
class Sections_element
virtual ~Sections_element()
{ }
+ // Return whether an output section is relro.
+ virtual bool
+ is_relro() const
+ { return false; }
+
+ // Record that an output section is relro.
+ virtual void
+ set_is_relro()
+ { }
+
+ // Create any required output sections. The only real
+ // implementation is in Output_section_definition.
+ virtual void
+ create_sections(Layout*)
+ { }
+
+ // Add any symbol being defined to the symbol table.
+ virtual void
+ add_symbols_to_table(Symbol_table*)
+ { }
+
+ // Finalize symbols and check assertions.
+ virtual void
+ finalize_symbols(Symbol_table*, const Layout*, uint64_t*)
+ { }
+
+ // Return the output section name to use for an input file name and
+ // section name. This only real implementation is in
+ // Output_section_definition.
+ virtual const char*
+ output_section_name(const char*, const char*, Output_section***)
+ { return NULL; }
+
+ // Initialize OSP with an output section.
+ virtual void
+ orphan_section_init(Orphan_section_placement*,
+ Script_sections::Elements_iterator)
+ { }
+
+ // Set section addresses. This includes applying assignments if the
+ // the expression is an absolute value.
+ virtual void
+ set_section_addresses(Symbol_table*, Layout*, uint64_t*, uint64_t*)
+ { }
+
+ // Check a constraint (ONLY_IF_RO, etc.) on an output section. If
+ // this section is constrained, and the input sections do not match,
+ // return the constraint, and set *POSD.
+ virtual Section_constraint
+ check_constraint(Output_section_definition**)
+ { return CONSTRAINT_NONE; }
+
+ // See if this is the alternate output section for a constrained
+ // output section. If it is, transfer the Output_section and return
+ // true. Otherwise return false.
+ virtual bool
+ alternate_constraint(Output_section_definition*, Section_constraint)
+ { return false; }
+
+ // Get the list of segments to use for an allocated section when
+ // using a PHDRS clause. If this is an allocated section, return
+ // the Output_section, and set *PHDRS_LIST (the first parameter) to
+ // the list of PHDRS to which it should be attached. If the PHDRS
+ // were not specified, don't change *PHDRS_LIST. When not returning
+ // NULL, set *ORPHAN (the second parameter) according to whether
+ // this is an orphan section--one that is not mentioned in the
+ // linker script.
+ virtual Output_section*
+ allocate_to_segment(String_list**, bool*)
+ { return NULL; }
+
+ // Look for an output section by name and return the address, the
+ // load address, the alignment, and the size. This is used when an
+ // expression refers to an output section which was not actually
+ // created. This returns true if the section was found, false
+ // otherwise. The only real definition is for
+ // Output_section_definition.
+ virtual bool
+ get_output_section_info(const char*, uint64_t*, uint64_t*, uint64_t*,
+ uint64_t*) const
+ { return false; }
+
+ // Return the associated Output_section if there is one.
+ virtual Output_section*
+ get_output_section() const
+ { return NULL; }
+
+ // Print the element for debugging purposes.
virtual void
print(FILE* f) const = 0;
};
: assignment_(name, namelen, val, provide, hidden)
{ }
+ // Add the symbol to the symbol table.
+ void
+ add_symbols_to_table(Symbol_table* symtab)
+ { this->assignment_.add_to_table(symtab); }
+
+ // Finalize the symbol.
+ void
+ finalize_symbols(Symbol_table* symtab, const Layout* layout,
+ uint64_t* dot_value)
+ {
+ this->assignment_.finalize_with_dot(symtab, layout, *dot_value, NULL);
+ }
+
+ // Set the section address. There is no section here, but if the
+ // value is absolute, we set the symbol. This permits us to use
+ // absolute symbols when setting dot.
+ void
+ set_section_addresses(Symbol_table* symtab, Layout* layout,
+ uint64_t* dot_value, uint64_t*)
+ {
+ this->assignment_.set_if_absolute(symtab, layout, true, *dot_value);
+ }
+
+ // Print for debugging.
void
print(FILE* f) const
{
Symbol_assignment assignment_;
};
+// An assignment to the dot symbol in a SECTIONS clause outside of an
+// output section.
+
+class Sections_element_dot_assignment : public Sections_element
+{
+ public:
+ Sections_element_dot_assignment(Expression* val)
+ : val_(val)
+ { }
+
+ // Finalize the symbol.
+ void
+ finalize_symbols(Symbol_table* symtab, const Layout* layout,
+ uint64_t* dot_value)
+ {
+ // We ignore the section of the result because outside of an
+ // output section definition the dot symbol is always considered
+ // to be absolute.
+ Output_section* dummy;
+ *dot_value = this->val_->eval_with_dot(symtab, layout, true, *dot_value,
+ NULL, &dummy);
+ }
+
+ // 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)
+ {
+ Output_section* dummy;
+ *dot_value = this->val_->eval_with_dot(symtab, layout, false, *dot_value,
+ NULL, &dummy);
+ *load_address = *dot_value;
+ }
+
+ // Print for debugging.
+ void
+ print(FILE* f) const
+ {
+ fprintf(f, " . = ");
+ this->val_->print(f);
+ fprintf(f, "\n");
+ }
+
+ private:
+ Expression* val_;
+};
+
// An assertion in a SECTIONS clause outside of an output section.
class Sections_element_assertion : public Sections_element
: assertion_(check, message, messagelen)
{ }
+ // Check the assertion.
+ void
+ finalize_symbols(Symbol_table* symtab, const Layout* layout, uint64_t*)
+ { this->assertion_.check(symtab, layout); }
+
+ // Print for debugging.
void
print(FILE* f) const
{
class Output_section_element
{
public:
+ // A list of input sections.
+ typedef std::list<Output_section::Simple_input_section> Input_section_list;
+
Output_section_element()
{ }
virtual ~Output_section_element()
{ }
+ // Return whether this element requires an output section to exist.
+ virtual bool
+ needs_output_section() const
+ { return false; }
+
+ // Add any symbol being defined to the symbol table.
+ virtual void
+ add_symbols_to_table(Symbol_table*)
+ { }
+
+ // Finalize symbols and check assertions.
+ virtual void
+ finalize_symbols(Symbol_table*, const Layout*, uint64_t*, Output_section**)
+ { }
+
+ // Return whether this element matches FILE_NAME and SECTION_NAME.
+ // The only real implementation is in Output_section_element_input.
+ virtual bool
+ match_name(const char*, const char*) const
+ { return false; }
+
+ // Set section addresses. This includes applying assignments if the
+ // the expression is an absolute value.
+ virtual void
+ set_section_addresses(Symbol_table*, Layout*, Output_section*, uint64_t,
+ uint64_t*, Output_section**, std::string*,
+ Input_section_list*)
+ { }
+
+ // Print the element for debugging purposes.
virtual void
print(FILE* f) const = 0;
+
+ protected:
+ // Return a fill string that is LENGTH bytes long, filling it with
+ // FILL.
+ std::string
+ get_fill_string(const std::string* fill, section_size_type length) const;
};
+std::string
+Output_section_element::get_fill_string(const std::string* fill,
+ section_size_type length) const
+{
+ std::string this_fill;
+ this_fill.reserve(length);
+ while (this_fill.length() + fill->length() <= length)
+ this_fill += *fill;
+ if (this_fill.length() < length)
+ this_fill.append(*fill, 0, length - this_fill.length());
+ return this_fill;
+}
+
// A symbol assignment in an output section.
class Output_section_element_assignment : public Output_section_element
: assignment_(name, namelen, val, provide, hidden)
{ }
+ // Add the symbol to the symbol table.
+ void
+ add_symbols_to_table(Symbol_table* symtab)
+ { this->assignment_.add_to_table(symtab); }
+
+ // Finalize the symbol.
+ void
+ finalize_symbols(Symbol_table* symtab, const Layout* layout,
+ uint64_t* dot_value, Output_section** dot_section)
+ {
+ this->assignment_.finalize_with_dot(symtab, layout, *dot_value,
+ *dot_section);
+ }
+
+ // Set the section address. There is no section here, but if the
+ // value is absolute, we set the symbol. This permits us to use
+ // absolute symbols when setting dot.
+ void
+ set_section_addresses(Symbol_table* symtab, Layout* layout, Output_section*,
+ uint64_t, uint64_t* dot_value, Output_section**,
+ std::string*, Input_section_list*)
+ {
+ this->assignment_.set_if_absolute(symtab, layout, true, *dot_value);
+ }
+
+ // Print for debugging.
void
print(FILE* f) const
{
Symbol_assignment assignment_;
};
+// An assignment to the dot symbol in an output section.
+
+class Output_section_element_dot_assignment : public Output_section_element
+{
+ public:
+ Output_section_element_dot_assignment(Expression* val)
+ : val_(val)
+ { }
+
+ // 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);
+ }
+
+ // 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*);
+
+ // Print for debugging.
+ void
+ print(FILE* f) const
+ {
+ fprintf(f, " . = ");
+ this->val_->print(f);
+ fprintf(f, "\n");
+ }
+
+ private:
+ Expression* val_;
+};
+
+// Update the dot symbol while setting section addresses.
+
+void
+Output_section_element_dot_assignment::set_section_addresses(
+ Symbol_table* symtab,
+ Layout* layout,
+ Output_section* output_section,
+ uint64_t,
+ uint64_t* dot_value,
+ 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);
+ if (next_dot < *dot_value)
+ gold_error(_("dot may not move backward"));
+ if (next_dot > *dot_value && output_section != NULL)
+ {
+ section_size_type length = convert_to_section_size_type(next_dot
+ - *dot_value);
+ Output_section_data* posd;
+ if (fill->empty())
+ posd = new Output_data_zero_fill(length, 0);
+ else
+ {
+ std::string this_fill = this->get_fill_string(fill, length);
+ posd = new Output_data_const(this_fill, 0);
+ }
+ output_section->add_output_section_data(posd);
+ layout->new_output_section_data_from_script(posd);
+ }
+ *dot_value = next_dot;
+}
+
// An assertion in an output section.
class Output_section_element_assertion : public Output_section_element
Script_assertion assertion_;
};
-// A data item in an output section.
+// We use a special instance of Output_section_data to handle BYTE,
+// SHORT, etc. This permits forward references to symbols in the
+// expressions.
-class Output_section_element_data : public Output_section_element
+class Output_data_expression : public Output_section_data
{
public:
- Output_section_element_data(int size, bool is_signed, Expression* val)
- : size_(size), is_signed_(is_signed), val_(val)
+ Output_data_expression(int size, bool is_signed, Expression* val,
+ const Symbol_table* symtab, const Layout* layout,
+ uint64_t dot_value, Output_section* dot_section)
+ : Output_section_data(size, 0, true),
+ is_signed_(is_signed), val_(val), symtab_(symtab),
+ layout_(layout), dot_value_(dot_value), dot_section_(dot_section)
{ }
+ protected:
+ // Write the data to the output file.
void
- print(FILE*) const;
+ do_write(Output_file*);
+
+ // Write the data to a buffer.
+ void
+ do_write_to_buffer(unsigned char*);
+
+ // Write to a map file.
+ void
+ do_print_to_mapfile(Mapfile* mapfile) const
+ { mapfile->print_output_data(this, _("** expression")); }
private:
- // The size in bytes.
- int size_;
- // Whether the value is signed.
+ template<bool big_endian>
+ void
+ endian_write_to_buffer(uint64_t, unsigned char*);
+
bool is_signed_;
- // The value.
Expression* val_;
+ const Symbol_table* symtab_;
+ const Layout* layout_;
+ uint64_t dot_value_;
+ Output_section* dot_section_;
};
-// Print for debugging.
+// Write the data element to the output file.
void
-Output_section_element_data::print(FILE* f) const
+Output_data_expression::do_write(Output_file* of)
{
- const char* s;
- switch (this->size_)
+ unsigned char* view = of->get_output_view(this->offset(), this->data_size());
+ this->write_to_buffer(view);
+ of->write_output_view(this->offset(), this->data_size(), view);
+}
+
+// Write the data element to a buffer.
+
+void
+Output_data_expression::do_write_to_buffer(unsigned char* buf)
+{
+ Output_section* dummy;
+ uint64_t val = this->val_->eval_with_dot(this->symtab_, this->layout_,
+ true, this->dot_value_,
+ this->dot_section_, &dummy);
+
+ if (parameters->target().is_big_endian())
+ this->endian_write_to_buffer<true>(val, buf);
+ else
+ this->endian_write_to_buffer<false>(val, buf);
+}
+
+template<bool big_endian>
+void
+Output_data_expression::endian_write_to_buffer(uint64_t val,
+ unsigned char* buf)
+{
+ switch (this->data_size())
{
case 1:
- s = "BYTE";
+ elfcpp::Swap_unaligned<8, big_endian>::writeval(buf, val);
break;
case 2:
- s = "SHORT";
+ elfcpp::Swap_unaligned<16, big_endian>::writeval(buf, val);
break;
case 4:
- s = "LONG";
+ elfcpp::Swap_unaligned<32, big_endian>::writeval(buf, val);
break;
case 8:
- if (this->is_signed_)
- s = "SQUAD";
- else
- s = "QUAD";
+ if (parameters->target().get_size() == 32)
+ {
+ val &= 0xffffffff;
+ if (this->is_signed_ && (val & 0x80000000) != 0)
+ val |= 0xffffffff00000000LL;
+ }
+ elfcpp::Swap_unaligned<64, big_endian>::writeval(buf, val);
break;
default:
gold_unreachable();
}
- fprintf(f, " %s(", s);
- this->val_->print(f);
- fprintf(f, ")\n");
}
-// A fill value setting in an output section.
+// A data item in an output section.
-class Output_section_element_fill : public Output_section_element
+class Output_section_element_data : public Output_section_element
{
public:
- Output_section_element_fill(Expression* val)
- : val_(val)
+ Output_section_element_data(int size, bool is_signed, Expression* val)
+ : size_(size), is_signed_(is_signed), val_(val)
{ }
+ // If there is a data item, then we must create an output section.
+ bool
+ needs_output_section() const
+ { return true; }
+
+ // Finalize symbols--we just need to update dot.
void
- print(FILE* f) const
- {
- fprintf(f, " FILL(");
- this->val_->print(f);
- fprintf(f, ")\n");
- }
+ finalize_symbols(Symbol_table*, const Layout*, uint64_t* dot_value,
+ Output_section**)
+ { *dot_value += this->size_; }
+
+ // Store the value in the section.
+ void
+ set_section_addresses(Symbol_table*, Layout*, Output_section*, uint64_t,
+ uint64_t* dot_value, Output_section**, std::string*,
+ Input_section_list*);
+
+ // Print for debugging.
+ void
+ print(FILE*) const;
+
+ private:
+ // The size in bytes.
+ int size_;
+ // Whether the value is signed.
+ bool is_signed_;
+ // The value.
+ Expression* val_;
+};
+
+// Store the value in the section.
+
+void
+Output_section_element_data::set_section_addresses(
+ Symbol_table* symtab,
+ Layout* layout,
+ Output_section* os,
+ uint64_t,
+ uint64_t* dot_value,
+ Output_section** dot_section,
+ std::string*,
+ Input_section_list*)
+{
+ gold_assert(os != NULL);
+ Output_data_expression* expression =
+ new Output_data_expression(this->size_, this->is_signed_, this->val_,
+ symtab, layout, *dot_value, *dot_section);
+ os->add_output_section_data(expression);
+ layout->new_output_section_data_from_script(expression);
+ *dot_value += this->size_;
+}
+
+// Print for debugging.
+
+void
+Output_section_element_data::print(FILE* f) const
+{
+ const char* s;
+ switch (this->size_)
+ {
+ case 1:
+ s = "BYTE";
+ break;
+ case 2:
+ s = "SHORT";
+ break;
+ case 4:
+ s = "LONG";
+ break;
+ case 8:
+ if (this->is_signed_)
+ s = "SQUAD";
+ else
+ s = "QUAD";
+ break;
+ default:
+ gold_unreachable();
+ }
+ fprintf(f, " %s(", s);
+ this->val_->print(f);
+ fprintf(f, ")\n");
+}
+
+// A fill value setting in an output section.
+
+class Output_section_element_fill : public Output_section_element
+{
+ public:
+ Output_section_element_fill(Expression* val)
+ : val_(val)
+ { }
+
+ // Update the fill value while setting section addresses.
+ void
+ set_section_addresses(Symbol_table* symtab, Layout* layout, Output_section*,
+ uint64_t, uint64_t* dot_value,
+ 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);
+ if (fill_section != NULL)
+ gold_warning(_("fill value is not absolute"));
+ // FIXME: The GNU linker supports fill values of arbitrary length.
+ unsigned char fill_buff[4];
+ elfcpp::Swap_unaligned<32, true>::writeval(fill_buff, fill_val);
+ fill->assign(reinterpret_cast<char*>(fill_buff), 4);
+ }
+
+ // Print for debugging.
+ void
+ print(FILE* f) const
+ {
+ fprintf(f, " FILL(");
+ this->val_->print(f);
+ fprintf(f, ")\n");
+ }
private:
// The new fill value.
Expression* val_;
};
+// 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
{
public:
- // Note that an Input_section_spec holds some pointers to vectors.
- // This constructor takes ownership of them. The parser is
- // implemented such that this works.
Output_section_element_input(const Input_section_spec* spec, bool keep);
+ // Finalize symbols--just update the value of the dot symbol.
+ void
+ finalize_symbols(Symbol_table*, const Layout*, uint64_t* dot_value,
+ Output_section** dot_section)
+ {
+ *dot_value = this->final_dot_value_;
+ *dot_section = this->final_dot_section_;
+ }
+
+ // See whether we match FILE_NAME and SECTION_NAME as an input
+ // section.
+ bool
+ match_name(const char* file_name, const char* section_name) const;
+
+ // Set the section address.
+ void
+ set_section_addresses(Symbol_table* symtab, Layout* layout, Output_section*,
+ uint64_t subalign, uint64_t* dot_value,
+ Output_section**, std::string* fill,
+ Input_section_list*);
+
+ // Print for debugging.
void
print(FILE* f) const;
struct Input_section_pattern
{
std::string pattern;
+ bool pattern_is_wildcard;
Sort_wildcard sort;
Input_section_pattern(const char* patterna, size_t patternlena,
Sort_wildcard sorta)
- : pattern(patterna, patternlena), sort(sorta)
+ : pattern(patterna, patternlena),
+ pattern_is_wildcard(is_wildcard_string(this->pattern)),
+ sort(sorta)
{ }
};
typedef std::vector<Input_section_pattern> Input_section_patterns;
- typedef std::vector<std::string> Filename_exclusions;
+ // Filename_exclusions is a pair of filename pattern and a bool
+ // indicating whether the filename is a wildcard.
+ typedef std::vector<std::pair<std::string, bool> > Filename_exclusions;
+
+ // Return whether STRING matches PATTERN, where IS_WILDCARD_PATTERN
+ // indicates whether this is a wildcard pattern.
+ static inline bool
+ match(const char* string, const char* pattern, bool is_wildcard_pattern)
+ {
+ return (is_wildcard_pattern
+ ? fnmatch(pattern, string, 0) == 0
+ : strcmp(string, pattern) == 0);
+ }
+
+ // See if we match a file name.
+ bool
+ match_file_name(const char* file_name) const;
- // The file name pattern.
+ // The file name pattern. If this is the empty string, we match all
+ // files.
std::string filename_pattern_;
+ // Whether the file name pattern is a wildcard.
+ bool filename_is_wildcard_;
// How the file names should be sorted. This may only be
// SORT_WILDCARD_NONE or SORT_WILDCARD_BY_NAME.
Sort_wildcard filename_sort_;
Input_section_patterns input_section_patterns_;
// Whether to keep this section when garbage collecting.
bool keep_;
+ // The value of dot after including all matching sections.
+ uint64_t final_dot_value_;
+ // The section where dot is defined after including all matching
+ // sections.
+ Output_section* final_dot_section_;
};
// Construct Output_section_element_input. The parser records strings
Output_section_element_input::Output_section_element_input(
const Input_section_spec* spec,
bool keep)
- : filename_pattern_(spec->file.name.value, spec->file.name.length),
+ : filename_pattern_(),
+ filename_is_wildcard_(false),
filename_sort_(spec->file.sort),
filename_exclusions_(),
input_section_patterns_(),
- keep_(keep)
+ keep_(keep),
+ final_dot_value_(0),
+ final_dot_section_(NULL)
{
+ // The filename pattern "*" is common, and matches all files. Turn
+ // it into the empty string.
+ if (spec->file.name.length != 1 || spec->file.name.value[0] != '*')
+ this->filename_pattern_.assign(spec->file.name.value,
+ spec->file.name.length);
+ this->filename_is_wildcard_ = is_wildcard_string(this->filename_pattern_);
+
if (spec->input_sections.exclude != NULL)
{
for (String_list::const_iterator p =
spec->input_sections.exclude->begin();
p != spec->input_sections.exclude->end();
++p)
- this->filename_exclusions_.push_back(*p);
+ {
+ bool is_wildcard = is_wildcard_string(*p);
+ this->filename_exclusions_.push_back(std::make_pair(*p,
+ is_wildcard));
+ }
}
if (spec->input_sections.sections != NULL)
}
}
+// See whether we match FILE_NAME.
+
+bool
+Output_section_element_input::match_file_name(const char* file_name) const
+{
+ if (!this->filename_pattern_.empty())
+ {
+ // If we were called with no filename, we refuse to match a
+ // pattern which requires a file name.
+ if (file_name == NULL)
+ return false;
+
+ if (!match(file_name, this->filename_pattern_.c_str(),
+ this->filename_is_wildcard_))
+ return false;
+ }
+
+ if (file_name != NULL)
+ {
+ // Now we have to see whether FILE_NAME matches one of the
+ // exclusion patterns, if any.
+ for (Filename_exclusions::const_iterator p =
+ this->filename_exclusions_.begin();
+ p != this->filename_exclusions_.end();
+ ++p)
+ {
+ if (match(file_name, p->first.c_str(), p->second))
+ return false;
+ }
+ }
+
+ return true;
+}
+
+// See whether we match FILE_NAME and SECTION_NAME.
+
+bool
+Output_section_element_input::match_name(const char* file_name,
+ const char* section_name) const
+{
+ if (!this->match_file_name(file_name))
+ return false;
+
+ // If there are no section name patterns, then we match.
+ if (this->input_section_patterns_.empty())
+ return true;
+
+ // See whether we match the section name patterns.
+ for (Input_section_patterns::const_iterator p =
+ this->input_section_patterns_.begin();
+ p != this->input_section_patterns_.end();
+ ++p)
+ {
+ if (match(section_name, p->pattern.c_str(), p->pattern_is_wildcard))
+ return true;
+ }
+
+ // We didn't match any section names, so we didn't match.
+ return false;
+}
+
+// Information we use to sort the input sections.
+
+class Input_section_info
+{
+ public:
+ Input_section_info(const Output_section::Simple_input_section& inputsection)
+ : input_section_(inputsection), section_name_(),
+ size_(0), addralign_(1)
+ { }
+
+ // Return the simple input section.
+ const Output_section::Simple_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 aname)
+ { this->section_name_ = aname; }
+
+ // Return the section size.
+ uint64_t
+ size() const
+ { return this->size_; }
+
+ // Set the section size.
+ void
+ set_size(uint64_t sec_size)
+ { this->size_ = sec_size; }
+
+ // Return the address alignment.
+ uint64_t
+ addralign() const
+ { return this->addralign_; }
+
+ // Set the address alignment.
+ void
+ set_addralign(uint64_t addr_align)
+ { this->addralign_ = addr_align; }
+
+ private:
+ // Input section, can be a relaxed section.
+ Output_section::Simple_input_section input_section_;
+ // Name of the section.
+ std::string section_name_;
+ // Section size.
+ uint64_t size_;
+ // Address alignment.
+ uint64_t addralign_;
+};
+
+// A class to sort the input sections.
+
+class Input_section_sorter
+{
+ public:
+ Input_section_sorter(Sort_wildcard filename_sort, Sort_wildcard section_sort)
+ : filename_sort_(filename_sort), section_sort_(section_sort)
+ { }
+
+ bool
+ operator()(const Input_section_info&, const Input_section_info&) const;
+
+ private:
+ Sort_wildcard filename_sort_;
+ Sort_wildcard section_sort_;
+};
+
+bool
+Input_section_sorter::operator()(const Input_section_info& isi1,
+ const Input_section_info& isi2) const
+{
+ if (this->section_sort_ == SORT_WILDCARD_BY_NAME
+ || this->section_sort_ == SORT_WILDCARD_BY_NAME_BY_ALIGNMENT
+ || (this->section_sort_ == SORT_WILDCARD_BY_ALIGNMENT_BY_NAME
+ && isi1.addralign() == isi2.addralign()))
+ {
+ if (isi1.section_name() != isi2.section_name())
+ return isi1.section_name() < isi2.section_name();
+ }
+ if (this->section_sort_ == SORT_WILDCARD_BY_ALIGNMENT
+ || this->section_sort_ == SORT_WILDCARD_BY_NAME_BY_ALIGNMENT
+ || this->section_sort_ == SORT_WILDCARD_BY_ALIGNMENT_BY_NAME)
+ {
+ if (isi1.addralign() != isi2.addralign())
+ return isi1.addralign() < isi2.addralign();
+ }
+ if (this->filename_sort_ == SORT_WILDCARD_BY_NAME)
+ {
+ if (isi1.relobj()->name() != isi2.relobj()->name())
+ return (isi1.relobj()->name() < isi2.relobj()->name());
+ }
+
+ // Otherwise we leave them in the same order.
+ return false;
+}
+
+// Set the section address. Look in INPUT_SECTIONS for sections which
+// match this spec, sort them as specified, and add them to the output
+// section.
+
+void
+Output_section_element_input::set_section_addresses(
+ Symbol_table*,
+ Layout* layout,
+ Output_section* output_section,
+ uint64_t subalign,
+ uint64_t* dot_value,
+ Output_section** dot_section,
+ std::string* fill,
+ Input_section_list* input_sections)
+{
+ // We build a list of sections which match each
+ // Input_section_pattern.
+
+ typedef std::vector<std::vector<Input_section_info> > Matching_sections;
+ size_t input_pattern_count = this->input_section_patterns_.size();
+ if (input_pattern_count == 0)
+ input_pattern_count = 1;
+ Matching_sections matching_sections(input_pattern_count);
+
+ // Look through the list of sections for this output section. Add
+ // each one which matches to one of the elements of
+ // MATCHING_SECTIONS.
+
+ Input_section_list::iterator p = input_sections->begin();
+ while (p != input_sections->end())
+ {
+ Relobj* relobj = p->relobj();
+ unsigned int shndx = p->shndx();
+ Input_section_info isi(*p);
+
+ // Calling section_name and section_addralign is not very
+ // efficient.
+
+ // Lock the object so that we can get information about the
+ // section. This is OK since we know we are single-threaded
+ // here.
+ {
+ const Task* task = reinterpret_cast<const Task*>(-1);
+ Task_lock_obj<Object> tl(task, relobj);
+
+ isi.set_section_name(relobj->section_name(shndx));
+ if (p->is_relaxed_input_section())
+ {
+ // We use current data size because relxed section sizes may not
+ // have finalized yet.
+ isi.set_size(p->relaxed_input_section()->current_data_size());
+ isi.set_addralign(p->relaxed_input_section()->addralign());
+ }
+ else
+ {
+ isi.set_size(relobj->section_size(shndx));
+ isi.set_addralign(relobj->section_addralign(shndx));
+ }
+ }
+
+ if (!this->match_file_name(relobj->name().c_str()))
+ ++p;
+ else if (this->input_section_patterns_.empty())
+ {
+ matching_sections[0].push_back(isi);
+ p = input_sections->erase(p);
+ }
+ else
+ {
+ size_t i;
+ for (i = 0; i < input_pattern_count; ++i)
+ {
+ const Input_section_pattern&
+ isp(this->input_section_patterns_[i]);
+ if (match(isi.section_name().c_str(), isp.pattern.c_str(),
+ isp.pattern_is_wildcard))
+ break;
+ }
+
+ if (i >= this->input_section_patterns_.size())
+ ++p;
+ else
+ {
+ matching_sections[i].push_back(isi);
+ p = input_sections->erase(p);
+ }
+ }
+ }
+
+ // Look through MATCHING_SECTIONS. Sort each one as specified,
+ // using a stable sort so that we get the default order when
+ // sections are otherwise equal. Add each input section to the
+ // output section.
+
+ uint64_t dot = *dot_value;
+ for (size_t i = 0; i < input_pattern_count; ++i)
+ {
+ if (matching_sections[i].empty())
+ continue;
+
+ gold_assert(output_section != NULL);
+
+ const Input_section_pattern& isp(this->input_section_patterns_[i]);
+ if (isp.sort != SORT_WILDCARD_NONE
+ || this->filename_sort_ != SORT_WILDCARD_NONE)
+ std::stable_sort(matching_sections[i].begin(),
+ matching_sections[i].end(),
+ Input_section_sorter(this->filename_sort_,
+ isp.sort));
+
+ for (std::vector<Input_section_info>::const_iterator q =
+ matching_sections[i].begin();
+ q != matching_sections[i].end();
+ ++q)
+ {
+ uint64_t this_subalign = q->addralign();
+ if (this_subalign < subalign)
+ this_subalign = subalign;
+
+ uint64_t address = align_address(dot, this_subalign);
+
+ if (address > dot && !fill->empty())
+ {
+ section_size_type length =
+ convert_to_section_size_type(address - dot);
+ std::string this_fill = this->get_fill_string(fill, length);
+ Output_section_data* posd = new Output_data_const(this_fill, 0);
+ output_section->add_output_section_data(posd);
+ layout->new_output_section_data_from_script(posd);
+ }
+
+ output_section->add_input_section_for_script(q->input_section(),
+ q->size(),
+ this_subalign);
+
+ dot = address + q->size();
+ }
+ }
+
+ // An SHF_TLS/SHT_NOBITS section does not take up any
+ // address space.
+ if (output_section == NULL
+ || (output_section->flags() & elfcpp::SHF_TLS) == 0
+ || output_section->type() != elfcpp::SHT_NOBITS)
+ *dot_value = dot;
+
+ this->final_dot_value_ = *dot_value;
+ this->final_dot_section_ = *dot_section;
+}
+
// Print for debugging.
void
{
if (need_comma)
fprintf(f, ", ");
- fprintf(f, "%s", p->c_str());
+ fprintf(f, "%s", p->first.c_str());
need_comma = true;
}
fprintf(f, ")");
class Output_section_definition : public Sections_element
{
public:
+ typedef Output_section_element::Input_section_list Input_section_list;
+
Output_section_definition(const char* name, size_t namelen,
const Parser_output_section_header* header);
void
add_symbol_assignment(const char* name, size_t length, Expression* value,
bool provide, bool hidden);
+
+ // Add an assignment to the special dot symbol.
+ void
+ add_dot_assignment(Expression* value);
+
// Add an assertion.
void
add_assertion(Expression* check, const char* message, size_t messagelen);
void
add_input_section(const Input_section_spec* spec, bool keep);
+ // Return whether the output section is relro.
+ bool
+ is_relro() const
+ { return this->is_relro_; }
+
+ // Record that the output section is relro.
+ void
+ set_is_relro()
+ { this->is_relro_ = true; }
+
+ // Create any required output sections.
+ void
+ create_sections(Layout*);
+
+ // Add any symbols being defined to the symbol table.
+ void
+ add_symbols_to_table(Symbol_table* symtab);
+
+ // Finalize symbols and check assertions.
+ void
+ finalize_symbols(Symbol_table*, const Layout*, uint64_t*);
+
+ // Return the output section name to use for an input file name and
+ // section name.
+ const char*
+ output_section_name(const char* file_name, const char* section_name,
+ Output_section***);
+
+ // 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);
+
+ // Check a constraint (ONLY_IF_RO, etc.) on an output section. If
+ // this section is constrained, and the input sections do not match,
+ // return the constraint, and set *POSD.
+ Section_constraint
+ check_constraint(Output_section_definition** posd);
+
+ // See if this is the alternate output section for a constrained
+ // output section. If it is, transfer the Output_section and return
+ // true. Otherwise return false.
+ bool
+ alternate_constraint(Output_section_definition*, Section_constraint);
+
+ // Get the list of segments to use for an allocated section when
+ // using a PHDRS clause.
+ Output_section*
+ allocate_to_segment(String_list** phdrs_list, bool* orphan);
+
+ // Look for an output section by name and return the address, the
+ // load address, the alignment, and the size. This is used when an
+ // expression refers to an output section which was not actually
+ // created. This returns true if the section was found, false
+ // otherwise.
+ bool
+ get_output_section_info(const char*, uint64_t*, uint64_t*, uint64_t*,
+ uint64_t*) const;
+
+ // Return the associated Output_section if there is one.
+ Output_section*
+ get_output_section() const
+ { return this->output_section_; }
+
// Print the contents to the FILE. This is for debugging.
void
print(FILE*) const;
Expression* align_;
// The input section alignment. This may be NULL.
Expression* subalign_;
+ // The constraint, if any.
+ Section_constraint constraint_;
// The fill value. This may be NULL.
Expression* fill_;
+ // The list of segments this section should go into. This may be
+ // NULL.
+ String_list* phdrs_;
// The list of elements defining the section.
Output_section_elements elements_;
+ // The Output_section created for this definition. This will be
+ // NULL if none was created.
+ Output_section* output_section_;
+ // The address after it has been evaluated.
+ uint64_t evaluated_address_;
+ // The load address after it has been evaluated.
+ uint64_t evaluated_load_address_;
+ // The alignment after it has been evaluated.
+ uint64_t evaluated_addralign_;
+ // The output section is relro.
+ bool is_relro_;
};
// Constructor.
load_address_(header->load_address),
align_(header->align),
subalign_(header->subalign),
+ constraint_(header->constraint),
fill_(NULL),
- elements_()
+ phdrs_(NULL),
+ elements_(),
+ output_section_(NULL),
+ evaluated_address_(0),
+ evaluated_load_address_(0),
+ evaluated_addralign_(0),
+ is_relro_(false)
{
}
Output_section_definition::finish(const Parser_output_section_trailer* trailer)
{
this->fill_ = trailer->fill;
+ this->phdrs_ = trailer->phdrs;
}
// Add a symbol to be defined.
this->elements_.push_back(p);
}
+// Add an assignment to the special dot symbol.
+
+void
+Output_section_definition::add_dot_assignment(Expression* value)
+{
+ Output_section_element* p = new Output_section_element_dot_assignment(value);
+ this->elements_.push_back(p);
+}
+
// Add an assertion.
void
this->elements_.push_back(p);
}
-// Print for debugging.
+// Create any required output sections. We need an output section if
+// there is a data statement here.
void
-Output_section_definition::print(FILE* f) const
+Output_section_definition::create_sections(Layout* layout)
{
- fprintf(f, " %s ", this->name_.c_str());
-
- if (this->address_ != NULL)
+ if (this->output_section_ != NULL)
+ return;
+ for (Output_section_elements::const_iterator p = this->elements_.begin();
+ p != this->elements_.end();
+ ++p)
{
- this->address_->print(f);
- fprintf(f, " ");
+ if ((*p)->needs_output_section())
+ {
+ const char* name = this->name_.c_str();
+ this->output_section_ = layout->make_output_section_for_script(name);
+ return;
+ }
}
+}
- fprintf(f, ": ");
+// Add any symbols being defined to the symbol table.
- if (this->load_address_ != NULL)
- {
- fprintf(f, "AT(");
- this->load_address_->print(f);
- fprintf(f, ") ");
- }
+void
+Output_section_definition::add_symbols_to_table(Symbol_table* symtab)
+{
+ for (Output_section_elements::iterator p = this->elements_.begin();
+ p != this->elements_.end();
+ ++p)
+ (*p)->add_symbols_to_table(symtab);
+}
- if (this->align_ != NULL)
- {
- fprintf(f, "ALIGN(");
- this->align_->print(f);
- fprintf(f, ") ");
- }
+// Finalize symbols and check assertions.
- if (this->subalign_ != NULL)
+void
+Output_section_definition::finalize_symbols(Symbol_table* symtab,
+ const Layout* layout,
+ uint64_t* dot_value)
+{
+ if (this->output_section_ != NULL)
+ *dot_value = this->output_section_->address();
+ else
{
- fprintf(f, "SUBALIGN(");
- this->subalign_->print(f);
- fprintf(f, ") ");
+ 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);
+ }
+ if (this->align_ != NULL)
+ {
+ Output_section* dummy;
+ uint64_t align = this->align_->eval_with_dot(symtab, layout, true,
+ *dot_value,
+ NULL,
+ &dummy);
+ address = align_address(address, align);
+ }
+ *dot_value = address;
+ }
+
+ Output_section* dot_section = this->output_section_;
+ for (Output_section_elements::iterator p = this->elements_.begin();
+ p != this->elements_.end();
+ ++p)
+ (*p)->finalize_symbols(symtab, layout, dot_value, &dot_section);
+}
+
+// Return the output section name to use for an input section name.
+
+const char*
+Output_section_definition::output_section_name(const char* file_name,
+ const char* section_name,
+ Output_section*** slot)
+{
+ // 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))
+ {
+ // We found a match for NAME, which means that it should go
+ // into this output section.
+ *slot = &this->output_section_;
+ return this->name_.c_str();
+ }
+ }
+
+ // We don't know about this section name.
+ return NULL;
+}
+
+// Set the section address. Note that the OUTPUT_SECTION_ field will
+// be NULL if no input sections were mapped to this output section.
+// We still have to adjust dot and process symbol assignments.
+
+void
+Output_section_definition::set_section_addresses(Symbol_table* symtab,
+ Layout* layout,
+ uint64_t* dot_value,
+ uint64_t* load_address)
+{
+ uint64_t address;
+ if (this->address_ == NULL)
+ address = *dot_value;
+ else
+ {
+ Output_section* dummy;
+ address = this->address_->eval_with_dot(symtab, layout, true,
+ *dot_value, NULL, &dummy);
+ }
+
+ uint64_t align;
+ if (this->align_ == NULL)
+ {
+ if (this->output_section_ == NULL)
+ align = 0;
+ else
+ align = this->output_section_->addralign();
+ }
+ else
+ {
+ Output_section* align_section;
+ align = this->align_->eval_with_dot(symtab, layout, true, *dot_value,
+ NULL, &align_section);
+ if (align_section != NULL)
+ gold_warning(_("alignment of section %s is not absolute"),
+ this->name_.c_str());
+ if (this->output_section_ != NULL)
+ this->output_section_->set_addralign(align);
+ }
+
+ address = align_address(address, align);
+
+ uint64_t start_address = address;
+
+ *dot_value = address;
+
+ // 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_->set_address(address);
+
+ this->evaluated_address_ = address;
+ this->evaluated_addralign_ = align;
+
+ if (this->load_address_ == NULL)
+ this->evaluated_load_address_ = address;
+ else
+ {
+ Output_section* dummy;
+ uint64_t laddr =
+ 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(laddr);
+ this->evaluated_load_address_ = laddr;
+ }
+
+ uint64_t subalign;
+ if (this->subalign_ == NULL)
+ subalign = 0;
+ else
+ {
+ Output_section* subalign_section;
+ subalign = this->subalign_->eval_with_dot(symtab, layout, true,
+ *dot_value, NULL,
+ &subalign_section);
+ if (subalign_section != NULL)
+ gold_warning(_("subalign of section %s is not absolute"),
+ this->name_.c_str());
+ }
+
+ std::string fill;
+ if (this->fill_ != NULL)
+ {
+ // FIXME: The GNU linker supports fill values of arbitrary
+ // length.
+ Output_section* fill_section;
+ uint64_t fill_val = this->fill_->eval_with_dot(symtab, layout, true,
+ *dot_value,
+ NULL,
+ &fill_section);
+ if (fill_section != NULL)
+ gold_warning(_("fill of section %s is not absolute"),
+ this->name_.c_str());
+ unsigned char fill_buff[4];
+ elfcpp::Swap_unaligned<32, true>::writeval(fill_buff, fill_val);
+ fill.assign(reinterpret_cast<char*>(fill_buff), 4);
+ }
+
+ Input_section_list input_sections;
+ if (this->output_section_ != NULL)
+ {
+ // Get the list of input sections attached to this output
+ // section. This will leave the output section with only
+ // Output_section_data entries.
+ address += this->output_section_->get_input_sections(address,
+ fill,
+ &input_sections);
+ *dot_value = address;
+ }
+
+ Output_section* dot_section = this->output_section_;
+ for (Output_section_elements::iterator p = this->elements_.begin();
+ p != this->elements_.end();
+ ++p)
+ (*p)->set_section_addresses(symtab, layout, this->output_section_,
+ subalign, dot_value, &dot_section, &fill,
+ &input_sections);
+
+ gold_assert(input_sections.empty());
+
+ if (this->load_address_ == NULL || this->output_section_ == NULL)
+ *load_address = *dot_value;
+ 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();
+ }
+}
+
+// Check a constraint (ONLY_IF_RO, etc.) on an output section. If
+// this section is constrained, and the input sections do not match,
+// return the constraint, and set *POSD.
+
+Section_constraint
+Output_section_definition::check_constraint(Output_section_definition** posd)
+{
+ switch (this->constraint_)
+ {
+ case CONSTRAINT_NONE:
+ return CONSTRAINT_NONE;
+
+ case CONSTRAINT_ONLY_IF_RO:
+ if (this->output_section_ != NULL
+ && (this->output_section_->flags() & elfcpp::SHF_WRITE) != 0)
+ {
+ *posd = this;
+ return CONSTRAINT_ONLY_IF_RO;
+ }
+ return CONSTRAINT_NONE;
+
+ case CONSTRAINT_ONLY_IF_RW:
+ if (this->output_section_ != NULL
+ && (this->output_section_->flags() & elfcpp::SHF_WRITE) == 0)
+ {
+ *posd = this;
+ return CONSTRAINT_ONLY_IF_RW;
+ }
+ return CONSTRAINT_NONE;
+
+ case CONSTRAINT_SPECIAL:
+ if (this->output_section_ != NULL)
+ gold_error(_("SPECIAL constraints are not implemented"));
+ return CONSTRAINT_NONE;
+
+ default:
+ gold_unreachable();
+ }
+}
+
+// See if this is the alternate output section for a constrained
+// output section. If it is, transfer the Output_section and return
+// true. Otherwise return false.
+
+bool
+Output_section_definition::alternate_constraint(
+ Output_section_definition* posd,
+ Section_constraint constraint)
+{
+ if (this->name_ != posd->name_)
+ return false;
+
+ switch (constraint)
+ {
+ case CONSTRAINT_ONLY_IF_RO:
+ if (this->constraint_ != CONSTRAINT_ONLY_IF_RW)
+ return false;
+ break;
+
+ case CONSTRAINT_ONLY_IF_RW:
+ if (this->constraint_ != CONSTRAINT_ONLY_IF_RO)
+ return false;
+ break;
+
+ default:
+ gold_unreachable();
+ }
+
+ // We have found the alternate constraint. We just need to move
+ // over the Output_section. When constraints are used properly,
+ // THIS should not have an output_section pointer, as all the input
+ // sections should have matched the other definition.
+
+ if (this->output_section_ != NULL)
+ gold_error(_("mismatched definition for constrained sections"));
+
+ this->output_section_ = posd->output_section_;
+ posd->output_section_ = NULL;
+
+ if (this->is_relro_)
+ this->output_section_->set_is_relro();
+ else
+ this->output_section_->clear_is_relro();
+
+ return true;
+}
+
+// Get the list of segments to use for an allocated section when using
+// a PHDRS clause.
+
+Output_section*
+Output_section_definition::allocate_to_segment(String_list** phdrs_list,
+ bool* orphan)
+{
+ 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_;
+}
+
+// Look for an output section by name and return the address, the load
+// address, the alignment, and the size. This is used when an
+// expression refers to an output section which was not actually
+// created. This returns true if the section was found, false
+// otherwise.
+
+bool
+Output_section_definition::get_output_section_info(const char* name,
+ uint64_t* address,
+ uint64_t* load_address,
+ uint64_t* addr_align,
+ uint64_t* size) const
+{
+ if (this->name_ != name)
+ return false;
+
+ if (this->output_section_ != NULL)
+ {
+ *address = this->output_section_->address();
+ if (this->output_section_->has_load_address())
+ *load_address = this->output_section_->load_address();
+ else
+ *load_address = *address;
+ *addr_align = this->output_section_->addralign();
+ *size = this->output_section_->current_data_size();
+ }
+ else
+ {
+ *address = this->evaluated_address_;
+ *load_address = this->evaluated_load_address_;
+ *addr_align = this->evaluated_addralign_;
+ *size = 0;
+ }
+
+ return true;
+}
+
+// Print for debugging.
+
+void
+Output_section_definition::print(FILE* f) const
+{
+ fprintf(f, " %s ", this->name_.c_str());
+
+ if (this->address_ != NULL)
+ {
+ this->address_->print(f);
+ fprintf(f, " ");
+ }
+
+ fprintf(f, ": ");
+
+ if (this->load_address_ != NULL)
+ {
+ fprintf(f, "AT(");
+ this->load_address_->print(f);
+ fprintf(f, ") ");
+ }
+
+ if (this->align_ != NULL)
+ {
+ fprintf(f, "ALIGN(");
+ this->align_->print(f);
+ fprintf(f, ") ");
+ }
+
+ if (this->subalign_ != NULL)
+ {
+ fprintf(f, "SUBALIGN(");
+ this->subalign_->print(f);
+ fprintf(f, ") ");
}
fprintf(f, "{\n");
this->fill_->print(f);
}
+ if (this->phdrs_ != NULL)
+ {
+ for (String_list::const_iterator p = this->phdrs_->begin();
+ p != this->phdrs_->end();
+ ++p)
+ fprintf(f, " :%s", p->c_str());
+ }
+
fprintf(f, "\n");
}
+// An output section created to hold orphaned input sections. These
+// do not actually appear in linker scripts. However, for convenience
+// when setting the output section addresses, we put a marker to these
+// sections in the appropriate place in the list of SECTIONS elements.
+
+class Orphan_output_section : public Sections_element
+{
+ public:
+ Orphan_output_section(Output_section* os)
+ : os_(os)
+ { }
+
+ // Return whether the orphan output section is relro. We can just
+ // check the output section because we always set the flag, if
+ // needed, just after we create the Orphan_output_section.
+ bool
+ is_relro() const
+ { return this->os_->is_relro(); }
+
+ // Initialize OSP with an output section. This should have been
+ // done already.
+ void
+ orphan_section_init(Orphan_section_placement*,
+ Script_sections::Elements_iterator)
+ { gold_unreachable(); }
+
+ // Set section addresses.
+ void
+ set_section_addresses(Symbol_table*, Layout*, uint64_t*, uint64_t*);
+
+ // Get the list of segments to use for an allocated section when
+ // using a PHDRS clause.
+ Output_section*
+ allocate_to_segment(String_list**, bool*);
+
+ // Return the associated Output_section.
+ Output_section*
+ get_output_section() const
+ { return this->os_; }
+
+ // Print for debugging.
+ void
+ print(FILE* f) const
+ {
+ fprintf(f, " marker for orphaned output section %s\n",
+ this->os_->name());
+ }
+
+ private:
+ Output_section* os_;
+};
+
+// Set section addresses.
+
+void
+Orphan_output_section::set_section_addresses(Symbol_table*, Layout*,
+ uint64_t* dot_value,
+ uint64_t* load_address)
+{
+ typedef std::list<Output_section::Simple_input_section> Input_section_list;
+
+ bool have_load_address = *load_address != *dot_value;
+
+ uint64_t address = *dot_value;
+ address = align_address(address, this->os_->addralign());
+
+ if ((this->os_->flags() & elfcpp::SHF_ALLOC) != 0)
+ {
+ this->os_->set_address(address);
+ if (have_load_address)
+ this->os_->set_load_address(align_address(*load_address,
+ this->os_->addralign()));
+ }
+
+ Input_section_list input_sections;
+ address += this->os_->get_input_sections(address, "", &input_sections);
+
+ for (Input_section_list::iterator p = input_sections.begin();
+ p != input_sections.end();
+ ++p)
+ {
+ uint64_t addr_align;
+ uint64_t size;
+
+ // We know what are single-threaded, so it is OK to lock the
+ // object.
+ {
+ const Task* task = reinterpret_cast<const Task*>(-1);
+ Task_lock_obj<Object> tl(task, p->relobj());
+ addr_align = p->relobj()->section_addralign(p->shndx());
+ if (p->is_relaxed_input_section())
+ // We use current data size because relxed section sizes may not
+ // have finalized yet.
+ size = p->relaxed_input_section()->current_data_size();
+ else
+ size = p->relobj()->section_size(p->shndx());
+ }
+
+ address = align_address(address, addr_align);
+ this->os_->add_input_section_for_script(*p, size, addr_align);
+ address += size;
+ }
+
+ // An SHF_TLS/SHT_NOBITS section does not take up any address space.
+ if (this->os_ == NULL
+ || (this->os_->flags() & elfcpp::SHF_TLS) == 0
+ || this->os_->type() != elfcpp::SHT_NOBITS)
+ {
+ if (!have_load_address)
+ *load_address = address;
+ else
+ *load_address += address - *dot_value;
+
+ *dot_value = address;
+ }
+}
+
+// Get the list of segments to use for an allocated section when using
+// a PHDRS clause. If this is an allocated section, return the
+// Output_section. We don't change the list of segments.
+
+Output_section*
+Orphan_output_section::allocate_to_segment(String_list**, bool* orphan)
+{
+ if ((this->os_->flags() & elfcpp::SHF_ALLOC) == 0)
+ return NULL;
+ *orphan = true;
+ return this->os_;
+}
+
+// Class Phdrs_element. A program header from a PHDRS clause.
+
+class Phdrs_element
+{
+ public:
+ Phdrs_element(const char* aname, size_t namelen, unsigned int atype,
+ bool include_filehdr, bool include_phdrs,
+ bool is_flags_valid, unsigned int flags,
+ Expression* aload_address)
+ : name_(aname, namelen), type_(atype), includes_filehdr_(include_filehdr),
+ includes_phdrs_(include_phdrs), is_flags_valid_(is_flags_valid),
+ flags_(flags), load_address_(aload_address), load_address_value_(0),
+ segment_(NULL)
+ { }
+
+ // Return the name of this segment.
+ const std::string&
+ name() const
+ { return this->name_; }
+
+ // Return the type of the segment.
+ unsigned int
+ type() const
+ { return this->type_; }
+
+ // Whether to include the file header.
+ bool
+ includes_filehdr() const
+ { return this->includes_filehdr_; }
+
+ // Whether to include the program headers.
+ bool
+ includes_phdrs() const
+ { return this->includes_phdrs_; }
+
+ // Return whether there is a load address.
+ bool
+ has_load_address() const
+ { return this->load_address_ != NULL; }
+
+ // Evaluate the load address expression if there is one.
+ void
+ eval_load_address(Symbol_table* symtab, Layout* alayout)
+ {
+ if (this->load_address_ != NULL)
+ this->load_address_value_ = this->load_address_->eval(symtab, alayout,
+ true);
+ }
+
+ // Return the load address.
+ uint64_t
+ load_address() const
+ {
+ gold_assert(this->load_address_ != NULL);
+ return this->load_address_value_;
+ }
+
+ // Create the segment.
+ Output_segment*
+ create_segment(Layout* layout)
+ {
+ this->segment_ = layout->make_output_segment(this->type_, this->flags_);
+ return this->segment_;
+ }
+
+ // Return the segment.
+ Output_segment*
+ segment()
+ { return this->segment_; }
+
+ // Release the segment.
+ void
+ release_segment()
+ { this->segment_ = NULL; }
+
+ // Set the segment flags if appropriate.
+ void
+ set_flags_if_valid()
+ {
+ if (this->is_flags_valid_)
+ this->segment_->set_flags(this->flags_);
+ }
+
+ // Print for debugging.
+ void
+ print(FILE*) const;
+
+ private:
+ // The name used in the script.
+ std::string name_;
+ // The type of the segment (PT_LOAD, etc.).
+ unsigned int type_;
+ // Whether this segment includes the file header.
+ bool includes_filehdr_;
+ // Whether this segment includes the section headers.
+ bool includes_phdrs_;
+ // Whether the flags were explicitly specified.
+ bool is_flags_valid_;
+ // The flags for this segment (PF_R, etc.) if specified.
+ unsigned int flags_;
+ // The expression for the load address for this segment. This may
+ // be NULL.
+ Expression* load_address_;
+ // The actual load address from evaluating the expression.
+ uint64_t load_address_value_;
+ // The segment itself.
+ Output_segment* segment_;
+};
+
+// Print for debugging.
+
+void
+Phdrs_element::print(FILE* f) const
+{
+ fprintf(f, " %s 0x%x", this->name_.c_str(), this->type_);
+ if (this->includes_filehdr_)
+ fprintf(f, " FILEHDR");
+ if (this->includes_phdrs_)
+ fprintf(f, " PHDRS");
+ if (this->is_flags_valid_)
+ fprintf(f, " FLAGS(%u)", this->flags_);
+ if (this->load_address_ != NULL)
+ {
+ fprintf(f, " AT(");
+ this->load_address_->print(f);
+ fprintf(f, ")");
+ }
+ fprintf(f, ";\n");
+}
+
// Class Script_sections.
Script_sections::Script_sections()
: saw_sections_clause_(false),
in_sections_clause_(false),
sections_elements_(NULL),
- output_section_(NULL)
+ output_section_(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)
{
}
}
}
-// Add an assertion.
+// Add an assignment to the special dot symbol.
void
-Script_sections::add_assertion(Expression* check, const char* message,
- size_t messagelen)
+Script_sections::add_dot_assignment(Expression* val)
{
if (this->output_section_ != NULL)
- this->output_section_->add_assertion(check, message, messagelen);
+ this->output_section_->add_dot_assignment(val);
else
{
- Sections_element* p = new Sections_element_assertion(check, message,
- messagelen);
+ // 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);
}
}
-// Start processing entries for an output section.
+// Add an assertion.
+
+void
+Script_sections::add_assertion(Expression* check, const char* message,
+ size_t messagelen)
+{
+ if (this->output_section_ != NULL)
+ this->output_section_->add_assertion(check, message, messagelen);
+ else
+ {
+ Sections_element* p = new Sections_element_assertion(check, message,
+ messagelen);
+ this->sections_elements_->push_back(p);
+ }
+}
+
+// Start processing entries for an output section.
void
Script_sections::start_output_section(
this->output_section_->add_input_section(spec, keep);
}
+// This is called when we see DATA_SEGMENT_ALIGN. It means that any
+// subsequent output sections may be relro.
+
+void
+Script_sections::data_segment_align()
+{
+ if (this->saw_data_segment_align_)
+ gold_error(_("DATA_SEGMENT_ALIGN may only appear once in a linker script"));
+ gold_assert(!this->sections_elements_->empty());
+ Sections_elements::iterator p = this->sections_elements_->end();
+ --p;
+ this->data_segment_align_start_ = p;
+ this->saw_data_segment_align_ = true;
+}
+
+// This is called when we see DATA_SEGMENT_RELRO_END. It means that
+// any output sections seen since DATA_SEGMENT_ALIGN are relro.
+
+void
+Script_sections::data_segment_relro_end()
+{
+ if (this->saw_relro_end_)
+ gold_error(_("DATA_SEGMENT_RELRO_END may only appear once "
+ "in a linker script"));
+ this->saw_relro_end_ = true;
+
+ if (!this->saw_data_segment_align_)
+ gold_error(_("DATA_SEGMENT_RELRO_END must follow DATA_SEGMENT_ALIGN"));
+ else
+ {
+ Sections_elements::iterator p = this->data_segment_align_start_;
+ for (++p; p != this->sections_elements_->end(); ++p)
+ (*p)->set_is_relro();
+ }
+}
+
+// Create any required sections.
+
+void
+Script_sections::create_sections(Layout* layout)
+{
+ if (!this->saw_sections_clause_)
+ return;
+ for (Sections_elements::iterator p = this->sections_elements_->begin();
+ p != this->sections_elements_->end();
+ ++p)
+ (*p)->create_sections(layout);
+}
+
+// Add any symbols we are defining to the symbol table.
+
+void
+Script_sections::add_symbols_to_table(Symbol_table* symtab)
+{
+ if (!this->saw_sections_clause_)
+ return;
+ for (Sections_elements::iterator p = this->sections_elements_->begin();
+ p != this->sections_elements_->end();
+ ++p)
+ (*p)->add_symbols_to_table(symtab);
+}
+
+// Finalize symbols and check assertions.
+
+void
+Script_sections::finalize_symbols(Symbol_table* symtab, const Layout* layout)
+{
+ if (!this->saw_sections_clause_)
+ return;
+ uint64_t dot_value = 0;
+ for (Sections_elements::iterator p = this->sections_elements_->begin();
+ p != this->sections_elements_->end();
+ ++p)
+ (*p)->finalize_symbols(symtab, layout, &dot_value);
+}
+
+// Return the name of the output section to use for an input file name
+// and section name.
+
+const char*
+Script_sections::output_section_name(const char* file_name,
+ const char* section_name,
+ Output_section*** output_section_slot)
+{
+ 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);
+
+ if (ret != NULL)
+ {
+ // The special name /DISCARD/ means that the input section
+ // should be discarded.
+ if (strcmp(ret, "/DISCARD/") == 0)
+ {
+ *output_section_slot = NULL;
+ return NULL;
+ }
+ return ret;
+ }
+ }
+
+ // If we couldn't find a mapping for the name, the output section
+ // gets the name of the input section.
+
+ *output_section_slot = NULL;
+
+ return section_name;
+}
+
+// Place a marker for an orphan output section into the SECTIONS
+// clause.
+
+void
+Script_sections::place_orphan(Output_section* os)
+{
+ Orphan_section_placement* osp = this->orphan_section_placement_;
+ if (osp == NULL)
+ {
+ // Initialize the Orphan_section_placement structure.
+ osp = new Orphan_section_placement();
+ for (Sections_elements::iterator p = this->sections_elements_->begin();
+ p != this->sections_elements_->end();
+ ++p)
+ (*p)->orphan_section_init(osp, p);
+ gold_assert(!this->sections_elements_->empty());
+ Sections_elements::iterator last = this->sections_elements_->end();
+ --last;
+ osp->last_init(last);
+ this->orphan_section_placement_ = osp;
+ }
+
+ Orphan_output_section* orphan = new Orphan_output_section(os);
+
+ // Look for where to put ORPHAN.
+ Sections_elements::iterator* where;
+ if (osp->find_place(os, &where))
+ {
+ if ((**where)->is_relro())
+ os->set_is_relro();
+ else
+ os->clear_is_relro();
+
+ // We want to insert ORPHAN after *WHERE, and then update *WHERE
+ // so that the next one goes after this one.
+ Sections_elements::iterator p = *where;
+ gold_assert(p != this->sections_elements_->end());
+ ++p;
+ *where = this->sections_elements_->insert(p, orphan);
+ }
+ else
+ {
+ os->clear_is_relro();
+ // We don't have a place to put this orphan section. Put it,
+ // and all other sections like it, at the end, but before the
+ // sections which always come at the end.
+ Sections_elements::iterator last = osp->last_place();
+ *where = this->sections_elements_->insert(last, orphan);
+ }
+}
+
+// Set the addresses of all the output sections. Walk through all the
+// elements, tracking the dot symbol. Apply assignments which set
+// absolute symbol values, in case they are used when setting dot.
+// Fill in data statement values. As we find output sections, set the
+// address, set the address of all associated input sections, and
+// update dot. Return the segment which should hold the file header
+// and segment headers, if any.
+
+Output_segment*
+Script_sections::set_section_addresses(Symbol_table* symtab, Layout* layout)
+{
+ gold_assert(this->saw_sections_clause_);
+
+ // Implement ONLY_IF_RO/ONLY_IF_RW constraints. These are a pain
+ // for our representation.
+ for (Sections_elements::iterator p = this->sections_elements_->begin();
+ p != this->sections_elements_->end();
+ ++p)
+ {
+ Output_section_definition* posd;
+ Section_constraint failed_constraint = (*p)->check_constraint(&posd);
+ if (failed_constraint != CONSTRAINT_NONE)
+ {
+ Sections_elements::iterator q;
+ for (q = this->sections_elements_->begin();
+ q != this->sections_elements_->end();
+ ++q)
+ {
+ if (q != p)
+ {
+ if ((*q)->alternate_constraint(posd, failed_constraint))
+ break;
+ }
+ }
+
+ if (q == this->sections_elements_->end())
+ gold_error(_("no matching section constraint"));
+ }
+ }
+
+ // Force the alignment of the first TLS section to be the maximum
+ // alignment of all TLS sections.
+ Output_section* first_tls = NULL;
+ uint64_t tls_align = 0;
+ for (Sections_elements::const_iterator p = this->sections_elements_->begin();
+ p != this->sections_elements_->end();
+ ++p)
+ {
+ Output_section *os = (*p)->get_output_section();
+ if (os != NULL && (os->flags() & elfcpp::SHF_TLS) != 0)
+ {
+ if (first_tls == NULL)
+ first_tls = os;
+ if (os->addralign() > tls_align)
+ tls_align = os->addralign();
+ }
+ }
+ if (first_tls != NULL)
+ first_tls->set_addralign(tls_align);
+
+ // For a relocatable link, we implicitly set dot to zero.
+ uint64_t dot_value = 0;
+ uint64_t load_address = 0;
+
+ // Check to see if we want to use any of -Ttext, -Tdata and -Tbss options
+ // to set section addresses. If the script has any SEGMENT_START
+ // expression, we do not set the section addresses.
+ bool use_tsection_options =
+ (!this->saw_segment_start_expression_
+ && (parameters->options().user_set_Ttext()
+ || parameters->options().user_set_Tdata()
+ || parameters->options().user_set_Tbss()));
+
+ for (Sections_elements::iterator p = this->sections_elements_->begin();
+ p != this->sections_elements_->end();
+ ++p)
+ {
+ Output_section* os = (*p)->get_output_section();
+
+ // Handle -Ttext, -Tdata and -Tbss options. We do this by looking for
+ // the special sections by names and doing dot assignments.
+ if (use_tsection_options
+ && os != NULL
+ && (os->flags() & elfcpp::SHF_ALLOC) != 0)
+ {
+ uint64_t new_dot_value = dot_value;
+
+ if (parameters->options().user_set_Ttext()
+ && strcmp(os->name(), ".text") == 0)
+ new_dot_value = parameters->options().Ttext();
+ else if (parameters->options().user_set_Tdata()
+ && strcmp(os->name(), ".data") == 0)
+ new_dot_value = parameters->options().Tdata();
+ else if (parameters->options().user_set_Tbss()
+ && strcmp(os->name(), ".bss") == 0)
+ new_dot_value = parameters->options().Tbss();
+
+ // Update dot and load address if necessary.
+ if (new_dot_value < dot_value)
+ gold_error(_("dot may not move backward"));
+ else if (new_dot_value != dot_value)
+ {
+ dot_value = new_dot_value;
+ load_address = new_dot_value;
+ }
+ }
+
+ (*p)->set_section_addresses(symtab, layout, &dot_value, &load_address);
+ }
+
+ if (this->phdrs_elements_ != NULL)
+ {
+ for (Phdrs_elements::iterator p = this->phdrs_elements_->begin();
+ p != this->phdrs_elements_->end();
+ ++p)
+ (*p)->eval_load_address(symtab, layout);
+ }
+
+ return this->create_segments(layout);
+}
+
+// Sort the sections in order to put them into segments.
+
+class Sort_output_sections
+{
+ public:
+ bool
+ operator()(const Output_section* os1, const Output_section* os2) const;
+};
+
+bool
+Sort_output_sections::operator()(const Output_section* os1,
+ const Output_section* os2) const
+{
+ // Sort first by the load address.
+ uint64_t lma1 = (os1->has_load_address()
+ ? os1->load_address()
+ : os1->address());
+ uint64_t lma2 = (os2->has_load_address()
+ ? os2->load_address()
+ : os2->address());
+ if (lma1 != lma2)
+ return lma1 < lma2;
+
+ // Then sort by the virtual address.
+ if (os1->address() != os2->address())
+ return os1->address() < os2->address();
+
+ // Sort TLS sections to the end.
+ bool tls1 = (os1->flags() & elfcpp::SHF_TLS) != 0;
+ bool tls2 = (os2->flags() & elfcpp::SHF_TLS) != 0;
+ if (tls1 != tls2)
+ return tls2;
+
+ // Sort PROGBITS before NOBITS.
+ if (os1->type() == elfcpp::SHT_PROGBITS && os2->type() == elfcpp::SHT_NOBITS)
+ return true;
+ if (os1->type() == elfcpp::SHT_NOBITS && os2->type() == elfcpp::SHT_PROGBITS)
+ return false;
+
+ // Otherwise we don't care.
+ return false;
+}
+
+// Return whether OS is a BSS section. This is a SHT_NOBITS section.
+// We treat a section with the SHF_TLS flag set as taking up space
+// even if it is SHT_NOBITS (this is true of .tbss), as we allocate
+// space for them in the file.
+
+bool
+Script_sections::is_bss_section(const Output_section* os)
+{
+ return (os->type() == elfcpp::SHT_NOBITS
+ && (os->flags() & elfcpp::SHF_TLS) == 0);
+}
+
+// Return the size taken by the file header and the program headers.
+
+size_t
+Script_sections::total_header_size(Layout* layout) const
+{
+ size_t segment_count = layout->segment_count();
+ size_t file_header_size;
+ size_t segment_headers_size;
+ if (parameters->target().get_size() == 32)
+ {
+ file_header_size = elfcpp::Elf_sizes<32>::ehdr_size;
+ segment_headers_size = segment_count * elfcpp::Elf_sizes<32>::phdr_size;
+ }
+ else if (parameters->target().get_size() == 64)
+ {
+ file_header_size = elfcpp::Elf_sizes<64>::ehdr_size;
+ segment_headers_size = segment_count * elfcpp::Elf_sizes<64>::phdr_size;
+ }
+ else
+ gold_unreachable();
+
+ return file_header_size + segment_headers_size;
+}
+
+// Return the amount we have to subtract from the LMA to accomodate
+// headers of the given size. The complication is that the file
+// header have to be at the start of a page, as otherwise it will not
+// be at the start of the file.
+
+uint64_t
+Script_sections::header_size_adjustment(uint64_t lma,
+ size_t sizeof_headers) const
+{
+ const uint64_t abi_pagesize = parameters->target().abi_pagesize();
+ uint64_t hdr_lma = lma - sizeof_headers;
+ hdr_lma &= ~(abi_pagesize - 1);
+ return lma - hdr_lma;
+}
+
+// Create the PT_LOAD segments when using a SECTIONS clause. Returns
+// the segment which should hold the file header and segment headers,
+// if any.
+
+Output_segment*
+Script_sections::create_segments(Layout* layout)
+{
+ gold_assert(this->saw_sections_clause_);
+
+ if (parameters->options().relocatable())
+ return NULL;
+
+ if (this->saw_phdrs_clause())
+ return create_segments_from_phdrs_clause(layout);
+
+ Layout::Section_list sections;
+ layout->get_allocated_sections(§ions);
+
+ // Sort the sections by address.
+ std::stable_sort(sections.begin(), sections.end(), Sort_output_sections());
+
+ this->create_note_and_tls_segments(layout, §ions);
+
+ // Walk through the sections adding them to PT_LOAD segments.
+ const uint64_t abi_pagesize = parameters->target().abi_pagesize();
+ Output_segment* first_seg = NULL;
+ Output_segment* current_seg = NULL;
+ bool is_current_seg_readonly = true;
+ Layout::Section_list::iterator plast = sections.end();
+ uint64_t last_vma = 0;
+ uint64_t last_lma = 0;
+ uint64_t last_size = 0;
+ for (Layout::Section_list::iterator p = sections.begin();
+ p != sections.end();
+ ++p)
+ {
+ const uint64_t vma = (*p)->address();
+ const uint64_t lma = ((*p)->has_load_address()
+ ? (*p)->load_address()
+ : vma);
+ const uint64_t size = (*p)->current_data_size();
+
+ bool need_new_segment;
+ if (current_seg == NULL)
+ need_new_segment = true;
+ else if (lma - vma != last_lma - last_vma)
+ {
+ // This section has a different LMA relationship than the
+ // last one; we need a new segment.
+ need_new_segment = true;
+ }
+ else if (align_address(last_lma + last_size, abi_pagesize)
+ < align_address(lma, abi_pagesize))
+ {
+ // Putting this section in the segment would require
+ // skipping a page.
+ need_new_segment = true;
+ }
+ else if (is_bss_section(*plast) && !is_bss_section(*p))
+ {
+ // A non-BSS section can not follow a BSS section in the
+ // same segment.
+ need_new_segment = true;
+ }
+ else if (is_current_seg_readonly
+ && ((*p)->flags() & elfcpp::SHF_WRITE) != 0
+ && !parameters->options().omagic())
+ {
+ // Don't put a writable section in the same segment as a
+ // non-writable section.
+ need_new_segment = true;
+ }
+ else
+ {
+ // Otherwise, reuse the existing segment.
+ need_new_segment = false;
+ }
+
+ elfcpp::Elf_Word seg_flags =
+ Layout::section_flags_to_segment((*p)->flags());
+
+ if (need_new_segment)
+ {
+ current_seg = layout->make_output_segment(elfcpp::PT_LOAD,
+ seg_flags);
+ current_seg->set_addresses(vma, lma);
+ if (first_seg == NULL)
+ first_seg = current_seg;
+ is_current_seg_readonly = true;
+ }
+
+ current_seg->add_output_section(*p, seg_flags, false);
+
+ if (((*p)->flags() & elfcpp::SHF_WRITE) != 0)
+ is_current_seg_readonly = false;
+
+ plast = p;
+ last_vma = vma;
+ last_lma = lma;
+ last_size = size;
+ }
+
+ // An ELF program should work even if the program headers are not in
+ // a PT_LOAD segment. However, it appears that the Linux kernel
+ // does not set the AT_PHDR auxiliary entry in that case. It sets
+ // the load address to p_vaddr - p_offset of the first PT_LOAD
+ // segment. It then sets AT_PHDR to the load address plus the
+ // offset to the program headers, e_phoff in the file header. This
+ // fails when the program headers appear in the file before the
+ // first PT_LOAD segment. Therefore, we always create a PT_LOAD
+ // segment to hold the file header and the program headers. This is
+ // effectively what the GNU linker does, and it is slightly more
+ // efficient in any case. We try to use the first PT_LOAD segment
+ // if we can, otherwise we make a new one.
+
+ if (first_seg == NULL)
+ return NULL;
+
+ // -n or -N mean that the program is not demand paged and there is
+ // no need to put the program headers in a PT_LOAD segment.
+ if (parameters->options().nmagic() || parameters->options().omagic())
+ return NULL;
+
+ size_t sizeof_headers = this->total_header_size(layout);
+
+ uint64_t vma = first_seg->vaddr();
+ uint64_t lma = first_seg->paddr();
+
+ uint64_t subtract = this->header_size_adjustment(lma, sizeof_headers);
+
+ if ((lma & (abi_pagesize - 1)) >= sizeof_headers)
+ {
+ first_seg->set_addresses(vma - subtract, lma - subtract);
+ return first_seg;
+ }
+
+ // If there is no room to squeeze in the headers, then punt. The
+ // resulting executable probably won't run on GNU/Linux, but we
+ // trust that the user knows what they are doing.
+ if (lma < subtract || vma < subtract)
+ return NULL;
+
+ Output_segment* load_seg = layout->make_output_segment(elfcpp::PT_LOAD,
+ elfcpp::PF_R);
+ load_seg->set_addresses(vma - subtract, lma - subtract);
+
+ return load_seg;
+}
+
+// Create a PT_NOTE segment for each SHT_NOTE section and a PT_TLS
+// segment if there are any SHT_TLS sections.
+
+void
+Script_sections::create_note_and_tls_segments(
+ Layout* layout,
+ const Layout::Section_list* sections)
+{
+ gold_assert(!this->saw_phdrs_clause());
+
+ bool saw_tls = false;
+ for (Layout::Section_list::const_iterator p = sections->begin();
+ p != sections->end();
+ ++p)
+ {
+ if ((*p)->type() == elfcpp::SHT_NOTE)
+ {
+ elfcpp::Elf_Word seg_flags =
+ Layout::section_flags_to_segment((*p)->flags());
+ Output_segment* oseg = layout->make_output_segment(elfcpp::PT_NOTE,
+ seg_flags);
+ oseg->add_output_section(*p, seg_flags, false);
+
+ // Incorporate any subsequent SHT_NOTE sections, in the
+ // hopes that the script is sensible.
+ Layout::Section_list::const_iterator pnext = p + 1;
+ while (pnext != sections->end()
+ && (*pnext)->type() == elfcpp::SHT_NOTE)
+ {
+ seg_flags = Layout::section_flags_to_segment((*pnext)->flags());
+ oseg->add_output_section(*pnext, seg_flags, false);
+ p = pnext;
+ ++pnext;
+ }
+ }
+
+ if (((*p)->flags() & elfcpp::SHF_TLS) != 0)
+ {
+ if (saw_tls)
+ gold_error(_("TLS sections are not adjacent"));
+
+ elfcpp::Elf_Word seg_flags =
+ Layout::section_flags_to_segment((*p)->flags());
+ Output_segment* oseg = layout->make_output_segment(elfcpp::PT_TLS,
+ seg_flags);
+ oseg->add_output_section(*p, seg_flags, false);
+
+ 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, false);
+ p = pnext;
+ ++pnext;
+ }
+
+ saw_tls = true;
+ }
+ }
+}
+
+// Add a program header. The PHDRS clause is syntactically distinct
+// from the SECTIONS clause, but we implement it with the SECTIONS
+// support because PHDRS is useless if there is no SECTIONS clause.
+
+void
+Script_sections::add_phdr(const char* name, size_t namelen, unsigned int type,
+ bool includes_filehdr, bool includes_phdrs,
+ bool is_flags_valid, unsigned int flags,
+ Expression* load_address)
+{
+ if (this->phdrs_elements_ == NULL)
+ this->phdrs_elements_ = new Phdrs_elements();
+ this->phdrs_elements_->push_back(new Phdrs_element(name, namelen, type,
+ includes_filehdr,
+ includes_phdrs,
+ is_flags_valid, flags,
+ load_address));
+}
+
+// Return the number of segments we expect to create based on the
+// SECTIONS clause. This is used to implement SIZEOF_HEADERS.
+
+size_t
+Script_sections::expected_segment_count(const Layout* layout) const
+{
+ if (this->saw_phdrs_clause())
+ return this->phdrs_elements_->size();
+
+ Layout::Section_list sections;
+ layout->get_allocated_sections(§ions);
+
+ // We assume that we will need two PT_LOAD segments.
+ size_t ret = 2;
+
+ bool saw_note = false;
+ bool saw_tls = false;
+ for (Layout::Section_list::const_iterator p = sections.begin();
+ p != sections.end();
+ ++p)
+ {
+ if ((*p)->type() == elfcpp::SHT_NOTE)
+ {
+ // Assume that all note sections will fit into a single
+ // PT_NOTE segment.
+ if (!saw_note)
+ {
+ ++ret;
+ saw_note = true;
+ }
+ }
+ else if (((*p)->flags() & elfcpp::SHF_TLS) != 0)
+ {
+ // There can only be one PT_TLS segment.
+ if (!saw_tls)
+ {
+ ++ret;
+ saw_tls = true;
+ }
+ }
+ }
+
+ return ret;
+}
+
+// Create the segments from a PHDRS clause. Return the segment which
+// should hold the file header and program headers, if any.
+
+Output_segment*
+Script_sections::create_segments_from_phdrs_clause(Layout* layout)
+{
+ this->attach_sections_using_phdrs_clause(layout);
+ return this->set_phdrs_clause_addresses(layout);
+}
+
+// Create the segments from the PHDRS clause, and put the output
+// sections in them.
+
+void
+Script_sections::attach_sections_using_phdrs_clause(Layout* layout)
+{
+ typedef std::map<std::string, Output_segment*> Name_to_segment;
+ Name_to_segment name_to_segment;
+ for (Phdrs_elements::const_iterator p = this->phdrs_elements_->begin();
+ p != this->phdrs_elements_->end();
+ ++p)
+ name_to_segment[(*p)->name()] = (*p)->create_segment(layout);
+
+ // Walk through the output sections and attach them to segments.
+ // Output sections in the script which do not list segments are
+ // attached to the same set of segments as the immediately preceding
+ // output section.
+
+ String_list* phdr_names = NULL;
+ bool load_segments_only = false;
+ for (Sections_elements::const_iterator p = this->sections_elements_->begin();
+ p != this->sections_elements_->end();
+ ++p)
+ {
+ bool orphan;
+ String_list* old_phdr_names = phdr_names;
+ Output_section* os = (*p)->allocate_to_segment(&phdr_names, &orphan);
+ if (os == NULL)
+ continue;
+
+ if (phdr_names == NULL)
+ {
+ gold_error(_("allocated section not in any segment"));
+ 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)
+ {
+ // Enable PT_LOAD segments only filtering until we see another
+ // list of segment names.
+ load_segments_only = true;
+ }
+
+ bool in_load_segment = false;
+ for (String_list::const_iterator q = phdr_names->begin();
+ q != phdr_names->end();
+ ++q)
+ {
+ Name_to_segment::const_iterator r = name_to_segment.find(*q);
+ if (r == name_to_segment.end())
+ gold_error(_("no segment %s"), q->c_str());
+ else
+ {
+ if (load_segments_only
+ && r->second->type() != elfcpp::PT_LOAD)
+ continue;
+
+ elfcpp::Elf_Word seg_flags =
+ Layout::section_flags_to_segment(os->flags());
+ r->second->add_output_section(os, seg_flags, false);
+
+ if (r->second->type() == elfcpp::PT_LOAD)
+ {
+ if (in_load_segment)
+ gold_error(_("section in two PT_LOAD segments"));
+ in_load_segment = true;
+ }
+ }
+ }
+
+ if (!in_load_segment)
+ gold_error(_("allocated section not in any PT_LOAD segment"));
+ }
+}
+
+// Set the addresses for segments created from a PHDRS clause. Return
+// the segment which should hold the file header and program headers,
+// if any.
+
+Output_segment*
+Script_sections::set_phdrs_clause_addresses(Layout* layout)
+{
+ Output_segment* load_seg = NULL;
+ for (Phdrs_elements::const_iterator p = this->phdrs_elements_->begin();
+ p != this->phdrs_elements_->end();
+ ++p)
+ {
+ // Note that we have to set the flags after adding the output
+ // sections to the segment, as adding an output segment can
+ // change the flags.
+ (*p)->set_flags_if_valid();
+
+ Output_segment* oseg = (*p)->segment();
+
+ if (oseg->type() != elfcpp::PT_LOAD)
+ {
+ // The addresses of non-PT_LOAD segments are set from the
+ // PT_LOAD segments.
+ if ((*p)->has_load_address())
+ gold_error(_("may only specify load address for PT_LOAD segment"));
+ continue;
+ }
+
+ // The output sections should have addresses from the SECTIONS
+ // clause. The addresses don't have to be in order, so find the
+ // one with the lowest load address. Use that to set the
+ // address of the segment.
+
+ Output_section* osec = oseg->section_with_lowest_load_address();
+ if (osec == NULL)
+ {
+ oseg->set_addresses(0, 0);
+ continue;
+ }
+
+ uint64_t vma = osec->address();
+ uint64_t lma = osec->has_load_address() ? osec->load_address() : vma;
+
+ // Override the load address of the section with the load
+ // address specified for the segment.
+ if ((*p)->has_load_address())
+ {
+ if (osec->has_load_address())
+ gold_warning(_("PHDRS load address overrides "
+ "section %s load address"),
+ osec->name());
+
+ lma = (*p)->load_address();
+ }
+
+ bool headers = (*p)->includes_filehdr() && (*p)->includes_phdrs();
+ if (!headers && ((*p)->includes_filehdr() || (*p)->includes_phdrs()))
+ {
+ // We could support this if we wanted to.
+ gold_error(_("using only one of FILEHDR and PHDRS is "
+ "not currently supported"));
+ }
+ if (headers)
+ {
+ size_t sizeof_headers = this->total_header_size(layout);
+ uint64_t subtract = this->header_size_adjustment(lma,
+ sizeof_headers);
+ if (lma >= subtract && vma >= subtract)
+ {
+ lma -= subtract;
+ vma -= subtract;
+ }
+ else
+ {
+ gold_error(_("sections loaded on first page without room "
+ "for file and program headers "
+ "are not supported"));
+ }
+
+ if (load_seg != NULL)
+ gold_error(_("using FILEHDR and PHDRS on more than one "
+ "PT_LOAD segment is not currently supported"));
+ load_seg = oseg;
+ }
+
+ oseg->set_addresses(vma, lma);
+ }
+
+ return load_seg;
+}
+
+// Add the file header and segment headers to non-load segments
+// specified in the PHDRS clause.
+
+void
+Script_sections::put_headers_in_phdrs(Output_data* file_header,
+ Output_data* segment_headers)
+{
+ gold_assert(this->saw_phdrs_clause());
+ for (Phdrs_elements::iterator p = this->phdrs_elements_->begin();
+ p != this->phdrs_elements_->end();
+ ++p)
+ {
+ if ((*p)->type() != elfcpp::PT_LOAD)
+ {
+ if ((*p)->includes_phdrs())
+ (*p)->segment()->add_initial_output_data(segment_headers);
+ if ((*p)->includes_filehdr())
+ (*p)->segment()->add_initial_output_data(file_header);
+ }
+ }
+}
+
+// Look for an output section by name and return the address, the load
+// address, the alignment, and the size. This is used when an
+// expression refers to an output section which was not actually
+// created. This returns true if the section was found, false
+// otherwise.
+
+bool
+Script_sections::get_output_section_info(const char* name, uint64_t* address,
+ uint64_t* load_address,
+ uint64_t* addr_align,
+ uint64_t* size) const
+{
+ if (!this->saw_sections_clause_)
+ return false;
+ for (Sections_elements::const_iterator p = this->sections_elements_->begin();
+ p != this->sections_elements_->end();
+ ++p)
+ if ((*p)->get_output_section_info(name, address, load_address, addr_align,
+ size))
+ return true;
+ return false;
+}
+
+// Release all Output_segments. This remove all pointers to all
+// Output_segments.
+
+void
+Script_sections::release_segments()
+{
+ if (this->saw_phdrs_clause())
+ {
+ for (Phdrs_elements::const_iterator p = this->phdrs_elements_->begin();
+ p != this->phdrs_elements_->end();
+ ++p)
+ (*p)->release_segment();
+ }
+}
+
// Print the SECTIONS clause to F for debugging.
void
(*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.