X-Git-Url: https://oss.titaniummirror.com/gitweb?p=msp430-binutils.git;a=blobdiff_plain;f=gold%2Fscript.h;fp=gold%2Fscript.h;h=755bb7947df2fb4dbeea082805f8d50b63c5356a;hp=0000000000000000000000000000000000000000;hb=88750007d7869f178f0ba528f41efd3b74c424cf;hpb=6df9443a374e2b81278c61b8afc0a1eef7db280b diff --git a/gold/script.h b/gold/script.h new file mode 100644 index 0000000..755bb79 --- /dev/null +++ b/gold/script.h @@ -0,0 +1,441 @@ +// script.h -- handle linker scripts for gold -*- C++ -*- + +// Copyright 2006, 2007, 2008 Free Software Foundation, Inc. +// Written by Ian Lance Taylor . + +// 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 +#include +#include + +#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 + get_versions() const; + + // Return the list of dependencies for this version. + std::vector + 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 dependency_lists_; + std::vector expression_lists_; + std::vector 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, Expression* val, + bool provide, bool hidden) + : name_(name, namelen), val_(val), 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 + 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_; + // 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, 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_assignments; + + // We keep a list of all assertions whcih occur outside of a + // SECTIONS clause. + typedef std::vector 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)