99fff23b2e
* resolve.cc (Symbol_table::should_override): Add defined parameter. Change all callers. Test whether object is NULL before calling a method on it. (Symbol_table::report_resolve_problem): Add defined parameter. Change all callers. (Symbol_table::should_override_with_special): Likewise. * symtab.cc (Symbol_table::define_in_output_data): Add defined parameter. Change all callers. (Symbol_table::do_define_in_output_data): Likewise. (Symbol_table::define_in_output_segment): Likewise. (Symbol_table::do_define_in_output_segment): Likewise. (Symbol_table::define_as_constant): Likewise. (Symbol_table::do_define_as_constant): Likewise. * script.h (class Symbol_assignment): Add is_defsym parameter to constructor; change all callers. * script.cc (Script_options::add_symbol_assignment): Add is_defsym parameter. Change all callers. Add is_defsym_ field. (class Parser_closure): Add parsing_defsym parameter to constructor; change all callers. Add parsing_defsym accessor function. Add parsing_defsym_ field.
444 lines
14 KiB
C++
444 lines
14 KiB
C++
// script.h -- handle linker scripts for gold -*- C++ -*-
|
|
|
|
// Copyright 2006, 2007, 2008 Free Software Foundation, Inc.
|
|
// Written by Ian Lance Taylor <iant@google.com>.
|
|
|
|
// This file is part of gold.
|
|
|
|
// This program is free software; you can redistribute it and/or modify
|
|
// it under the terms of the GNU General Public License as published by
|
|
// the Free Software Foundation; either version 3 of the License, or
|
|
// (at your option) any later version.
|
|
|
|
// This program is distributed in the hope that it will be useful,
|
|
// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
// GNU General Public License for more details.
|
|
|
|
// You should have received a copy of the GNU General Public License
|
|
// along with this program; if not, write to the Free Software
|
|
// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
|
|
// MA 02110-1301, USA.
|
|
|
|
// We implement a subset of the original GNU ld linker script language
|
|
// for compatibility. The goal is not to implement the entire
|
|
// language. It is merely to implement enough to handle common uses.
|
|
// In particular we need to handle /usr/lib/libc.so on a typical
|
|
// GNU/Linux system, and we want to handle linker scripts used by the
|
|
// Linux kernel build.
|
|
|
|
#ifndef GOLD_SCRIPT_H
|
|
#define GOLD_SCRIPT_H
|
|
|
|
#include <cstdio>
|
|
#include <string>
|
|
#include <vector>
|
|
|
|
#include "script-sections.h"
|
|
|
|
namespace gold
|
|
{
|
|
|
|
class General_options;
|
|
class Command_line;
|
|
class Symbol_table;
|
|
class Layout;
|
|
class Mapfile;
|
|
class Input_argument;
|
|
class Input_arguments;
|
|
class Input_objects;
|
|
class Input_group;
|
|
class Input_file;
|
|
class Output_segment;
|
|
class Task_token;
|
|
class Workqueue;
|
|
struct Version_dependency_list;
|
|
struct Version_expression_list;
|
|
struct Version_tree;
|
|
|
|
// This class represents an expression in a linker script.
|
|
|
|
class Expression
|
|
{
|
|
protected:
|
|
// These should only be created by child classes.
|
|
Expression()
|
|
{ }
|
|
|
|
public:
|
|
virtual ~Expression()
|
|
{ }
|
|
|
|
// Return the value of the expression which is not permitted to
|
|
// refer to the dot symbol. CHECK_ASSERTIONS is true if we should
|
|
// check whether assertions are true.
|
|
uint64_t
|
|
eval(const Symbol_table*, const Layout*, bool check_assertions);
|
|
|
|
// Return the value of an expression which is permitted to refer to
|
|
// the dot symbol. DOT_VALUE is the absolute value of the dot
|
|
// symbol. DOT_SECTION is the section in which dot is defined; it
|
|
// should be NULL if the dot symbol has an absolute value (e.g., is
|
|
// defined in a SECTIONS clause outside of any output section
|
|
// definition). This sets *RESULT_SECTION to indicate where the
|
|
// value is defined. If the value is absolute *RESULT_SECTION will
|
|
// be NULL. Note that the returned value is still an absolute
|
|
// value; to get a section relative value the caller must subtract
|
|
// the section address.
|
|
uint64_t
|
|
eval_with_dot(const Symbol_table*, const Layout*, bool check_assertions,
|
|
uint64_t dot_value, Output_section* dot_section,
|
|
Output_section** result_section);
|
|
|
|
// Return the value of an expression which may or may not be
|
|
// permitted to refer to the dot symbol, depending on
|
|
// is_dot_available.
|
|
uint64_t
|
|
eval_maybe_dot(const Symbol_table*, const Layout*, bool check_assertions,
|
|
bool is_dot_available, uint64_t dot_value,
|
|
Output_section* dot_section,
|
|
Output_section** result_section);
|
|
|
|
// Print the expression to the FILE. This is for debugging.
|
|
virtual void
|
|
print(FILE*) const = 0;
|
|
|
|
protected:
|
|
struct Expression_eval_info;
|
|
|
|
public:
|
|
// Compute the value of the expression (implemented by child class).
|
|
// This is public rather than protected because it is called
|
|
// directly by children of Expression on other Expression objects.
|
|
virtual uint64_t
|
|
value(const Expression_eval_info*) = 0;
|
|
|
|
private:
|
|
// May not be copied.
|
|
Expression(const Expression&);
|
|
Expression& operator=(const Expression&);
|
|
};
|
|
|
|
|
|
// Version_script_info stores information parsed from the version
|
|
// script, either provided by --version-script or as part of a linker
|
|
// script. A single Version_script_info object per target is owned by
|
|
// Script_options.
|
|
|
|
class Version_script_info
|
|
{
|
|
public:
|
|
~Version_script_info();
|
|
|
|
// Clear everything.
|
|
void
|
|
clear();
|
|
|
|
// Return whether any version were defined in the version script.
|
|
bool
|
|
empty() const
|
|
{ return this->version_trees_.empty(); }
|
|
|
|
// If there is a version associated with SYMBOL, return true, and
|
|
// set *VERSION to the version. Otherwise, return false.
|
|
bool
|
|
get_symbol_version(const char* symbol, std::string* version) const
|
|
{ return this->get_symbol_version_helper(symbol, true, version); }
|
|
|
|
// Return whether this symbol matches the local: section of some
|
|
// version.
|
|
bool
|
|
symbol_is_local(const char* symbol) const
|
|
{ return this->get_symbol_version_helper(symbol, false, NULL); }
|
|
|
|
// Return the names of versions defined in the version script.
|
|
// Strings are allocated out of the stringpool given in the
|
|
// constructor.
|
|
std::vector<std::string>
|
|
get_versions() const;
|
|
|
|
// Return the list of dependencies for this version.
|
|
std::vector<std::string>
|
|
get_dependencies(const char* version) const;
|
|
|
|
// The following functions should only be used by the bison helper
|
|
// functions. They allocate new structs whose memory belongs to
|
|
// Version_script_info. The bison functions copy the information
|
|
// from the version script into these structs.
|
|
struct Version_dependency_list*
|
|
allocate_dependency_list();
|
|
|
|
struct Version_expression_list*
|
|
allocate_expression_list();
|
|
|
|
struct Version_tree*
|
|
allocate_version_tree();
|
|
|
|
// Print contents to the FILE. This is for debugging.
|
|
void
|
|
print(FILE*) const;
|
|
|
|
private:
|
|
void
|
|
print_expression_list(FILE* f, const Version_expression_list*) const;
|
|
|
|
bool get_symbol_version_helper(const char* symbol,
|
|
bool check_global,
|
|
std::string* pversion) const;
|
|
|
|
std::vector<struct Version_dependency_list*> dependency_lists_;
|
|
std::vector<struct Version_expression_list*> expression_lists_;
|
|
std::vector<struct Version_tree*> version_trees_;
|
|
};
|
|
|
|
// This class manages assignments to symbols. These can appear in
|
|
// three different locations in scripts: outside of a SECTIONS clause,
|
|
// within a SECTIONS clause, and within an output section definition
|
|
// within a SECTIONS clause. This can also appear on the command line
|
|
// via the --defsym command line option.
|
|
|
|
class Symbol_assignment
|
|
{
|
|
public:
|
|
Symbol_assignment(const char* name, size_t namelen, bool is_defsym,
|
|
Expression* val, bool provide, bool hidden)
|
|
: name_(name, namelen), val_(val), is_defsym_(is_defsym),
|
|
provide_(provide), hidden_(hidden), sym_(NULL)
|
|
{ }
|
|
|
|
// Add the symbol to the symbol table.
|
|
void
|
|
add_to_table(Symbol_table*);
|
|
|
|
// Finalize the symbol value.
|
|
void
|
|
finalize(Symbol_table*, const Layout*);
|
|
|
|
// Finalize the symbol value when it can refer to the dot symbol.
|
|
void
|
|
finalize_with_dot(Symbol_table*, const Layout*, uint64_t dot_value,
|
|
Output_section* dot_section);
|
|
|
|
// Set the symbol value, but only if the value is absolute. This is
|
|
// used while processing a SECTIONS clause. We assume that dot is
|
|
// an absolute value here. We do not check assertions.
|
|
void
|
|
set_if_absolute(Symbol_table*, const Layout*, bool is_dot_available,
|
|
uint64_t dot_value);
|
|
|
|
// Print the assignment to the FILE. This is for debugging.
|
|
void
|
|
print(FILE*) const;
|
|
|
|
private:
|
|
// Shared by finalize and finalize_with_dot.
|
|
void
|
|
finalize_maybe_dot(Symbol_table*, const Layout*, bool is_dot_available,
|
|
uint64_t dot_value, Output_section* dot_section);
|
|
|
|
// Sized version of finalize.
|
|
template<int size>
|
|
void
|
|
sized_finalize(Symbol_table*, const Layout*, bool is_dot_available,
|
|
uint64_t dot_value, Output_section*);
|
|
|
|
// Symbol name.
|
|
std::string name_;
|
|
// Expression to assign to symbol.
|
|
Expression* val_;
|
|
// True if this symbol is defined by a --defsym, false if it is
|
|
// defined in a linker script.
|
|
bool is_defsym_;
|
|
// Whether the assignment should be provided (only set if there is
|
|
// an undefined reference to the symbol.
|
|
bool provide_;
|
|
// Whether the assignment should be hidden.
|
|
bool hidden_;
|
|
// The entry in the symbol table.
|
|
Symbol* sym_;
|
|
};
|
|
|
|
// This class manages assertions in linker scripts. These can appear
|
|
// in all the places where a Symbol_assignment can appear.
|
|
|
|
class Script_assertion
|
|
{
|
|
public:
|
|
Script_assertion(Expression* check, const char* message,
|
|
size_t messagelen)
|
|
: check_(check), message_(message, messagelen)
|
|
{ }
|
|
|
|
// Check the assertion.
|
|
void
|
|
check(const Symbol_table*, const Layout*);
|
|
|
|
// Print the assertion to the FILE. This is for debugging.
|
|
void
|
|
print(FILE*) const;
|
|
|
|
private:
|
|
// The expression to check.
|
|
Expression* check_;
|
|
// The message to issue if the expression fails.
|
|
std::string message_;
|
|
};
|
|
|
|
// We can read a linker script in two different contexts: when
|
|
// initially parsing the command line, and when we find an input file
|
|
// which is actually a linker script. Also some of the data which can
|
|
// be set by a linker script can also be set via command line options
|
|
// like -e and --defsym. This means that we have a type of data which
|
|
// can be set both during command line option parsing and while
|
|
// reading input files. We store that data in an instance of this
|
|
// object. We will keep pointers to that instance in both the
|
|
// Command_line and Layout objects.
|
|
|
|
class Script_options
|
|
{
|
|
public:
|
|
Script_options();
|
|
|
|
// Add a symbol to be defined.
|
|
void
|
|
add_symbol_assignment(const char* name, size_t length, bool is_defsym,
|
|
Expression* value, bool provide, bool hidden);
|
|
|
|
// Add an assertion.
|
|
void
|
|
add_assertion(Expression* check, const char* message, size_t messagelen);
|
|
|
|
// Define a symbol from the command line.
|
|
bool
|
|
define_symbol(const char* definition);
|
|
|
|
// Create sections required by any linker scripts.
|
|
void
|
|
create_script_sections(Layout*);
|
|
|
|
// Add all symbol definitions to the symbol table.
|
|
void
|
|
add_symbols_to_table(Symbol_table*);
|
|
|
|
// Finalize the symbol values. Also check assertions.
|
|
void
|
|
finalize_symbols(Symbol_table*, const Layout*);
|
|
|
|
// Version information parsed from a version script. Everything
|
|
// else has a pointer to this object.
|
|
Version_script_info*
|
|
version_script_info()
|
|
{ return &this->version_script_info_; }
|
|
|
|
const Version_script_info*
|
|
version_script_info() const
|
|
{ return &this->version_script_info_; }
|
|
|
|
// A SECTIONS clause parsed from a linker script. Everything else
|
|
// has a pointer to this object.
|
|
Script_sections*
|
|
script_sections()
|
|
{ return &this->script_sections_; }
|
|
|
|
const Script_sections*
|
|
script_sections() const
|
|
{ return &this->script_sections_; }
|
|
|
|
// Whether we saw a SECTIONS clause.
|
|
bool
|
|
saw_sections_clause() const
|
|
{ return this->script_sections_.saw_sections_clause(); }
|
|
|
|
// Whether we saw a PHDRS clause.
|
|
bool
|
|
saw_phdrs_clause() const
|
|
{ return this->script_sections_.saw_phdrs_clause(); }
|
|
|
|
// Set section addresses using a SECTIONS clause. Return the
|
|
// segment which should hold the file header and segment headers;
|
|
// this may return NULL, in which case the headers are not in a
|
|
// loadable segment.
|
|
Output_segment*
|
|
set_section_addresses(Symbol_table*, Layout*);
|
|
|
|
// Print the script to the FILE. This is for debugging.
|
|
void
|
|
print(FILE*) const;
|
|
|
|
private:
|
|
// We keep a list of symbol assignments which occur outside of a
|
|
// SECTIONS clause.
|
|
typedef std::vector<Symbol_assignment*> Symbol_assignments;
|
|
|
|
// We keep a list of all assertions whcih occur outside of a
|
|
// SECTIONS clause.
|
|
typedef std::vector<Script_assertion*> Assertions;
|
|
|
|
// The entry address. This will be empty if not set.
|
|
std::string entry_;
|
|
// Symbols to set.
|
|
Symbol_assignments symbol_assignments_;
|
|
// Assertions to check.
|
|
Assertions assertions_;
|
|
// Version information parsed from a version script.
|
|
Version_script_info version_script_info_;
|
|
// Information from any SECTIONS clauses.
|
|
Script_sections script_sections_;
|
|
};
|
|
|
|
// Information about a script input that will persist during the whole linker
|
|
// run. Needed only during an incremental build to retrieve the input files
|
|
// added by this script.
|
|
|
|
class Script_info
|
|
{
|
|
public:
|
|
Script_info(Input_arguments* inputs)
|
|
: inputs_(inputs)
|
|
{ }
|
|
|
|
// Returns the input files included because of this script.
|
|
Input_arguments*
|
|
inputs()
|
|
{ return this->inputs_; }
|
|
|
|
private:
|
|
Input_arguments* inputs_;
|
|
};
|
|
|
|
// FILE was found as an argument on the command line, but was not
|
|
// recognized as an ELF file. Try to read it as a script. Return
|
|
// true if the file was handled. This has to handle /usr/lib/libc.so
|
|
// on a GNU/Linux system. *USED_NEXT_BLOCKER is set to indicate
|
|
// whether the function took over NEXT_BLOCKER.
|
|
|
|
bool
|
|
read_input_script(Workqueue*, Symbol_table*, Layout*, Dirsearch*, int,
|
|
Input_objects*, Mapfile*, Input_group*,
|
|
const Input_argument*, Input_file*,
|
|
Task_token* next_blocker, bool* used_next_blocker);
|
|
|
|
// FILE was found as an argument to --script (-T).
|
|
// Read it as a script, and execute its contents immediately.
|
|
|
|
bool
|
|
read_commandline_script(const char* filename, Command_line* cmdline);
|
|
|
|
// FILE was found as an argument to --version-script. Read it as a
|
|
// version script, and store its contents in
|
|
// cmdline->script_options()->version_script_info().
|
|
|
|
bool
|
|
read_version_script(const char* filename, Command_line* cmdline);
|
|
|
|
// FILENAME was found as an argument to --dynamic-list. Read it as a
|
|
// version script (actually, a versym_node from a version script), and
|
|
// store its contents in DYNAMIC_LIST.
|
|
|
|
bool
|
|
read_dynamic_list(const char* filename, Command_line* cmdline,
|
|
Script_options* dynamic_list);
|
|
|
|
} // End namespace gold.
|
|
|
|
#endif // !defined(GOLD_SCRIPT_H)
|