// script.h -- handle linker scripts for gold -*- C++ -*-
-// Copyright 2006, 2007 Free Software Foundation, Inc.
+// Copyright (C) 2006-2020 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
#ifndef GOLD_SCRIPT_H
#define GOLD_SCRIPT_H
+#include <cstdio>
+#include <string>
+#include <vector>
+
+#include "elfcpp.h"
+#include "script-sections.h"
+
namespace gold
{
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;
+struct Version_expression;
+class Lazy_demangler;
+class Incremental_script_entry;
+
+// 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. If RESULT_ALIGNMENT is not NULL, this sets
+ // *RESULT_ALIGNMENT to the alignment of the value of that alignment
+ // is larger than *RESULT_ALIGNMENT; this will only be non-zero if
+ // this is an ALIGN expression. If IS_SECTION_DOT_ASSIGMENT is true,
+ // we are evaluating an assignment to dot within an output section,
+ // and an absolute value should be interpreted as an offset within
+ // the section.
+ 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, uint64_t* result_alignment,
+ bool is_section_dot_assignment);
+
+ // Return the value of an expression which may or may not be
+ // permitted to refer to the dot symbol, depending on
+ // is_dot_available. If IS_SECTION_DOT_ASSIGMENT is true,
+ // we are evaluating an assignment to dot within an output section,
+ // and an absolute value should be interpreted as an offset within
+ // the section.
+ 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, uint64_t* result_alignment,
+ elfcpp::STT* type, elfcpp::STV* vis, unsigned char* nonvis,
+ bool is_section_dot_assignment, bool* is_valid_pointer);
+
+ // 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;
+
+ // Sets all symbols used in expressions as seen in a real ELF object.
+ virtual void
+ set_expr_sym_in_real_elf(Symbol_table*) const
+ { return; }
+
+ 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:
+ // The languages which can be specified in a versionn script.
+ enum Language
+ {
+ LANGUAGE_C, // No demangling.
+ LANGUAGE_CXX, // C++ demangling.
+ LANGUAGE_JAVA, // Java demangling.
+ LANGUAGE_COUNT
+ };
+
+ Version_script_info();
+
+ ~Version_script_info();
+
+ // Clear everything.
+ void
+ clear();
+
+ // Finalize the version control information.
+ void
+ finalize();
+
+ // Return whether the information is finalized.
+ bool
+ is_finalized() const
+ { return this->is_finalized_; }
+
+ // 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, and *IS_GLOBAL to whether the symbol
+ // should be global. Otherwise, return false.
+ bool
+ get_symbol_version(const char* symbol, std::string* version,
+ bool* is_global) const;
+
+ // Return whether this symbol matches the local: section of some
+ // version.
+ bool
+ symbol_is_local(const char* symbol) const
+ {
+ bool is_global;
+ return (this->get_symbol_version(symbol, NULL, &is_global)
+ && !is_global);
+ }
+
+ // Return the names of versions defined in the version script.
+ 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();
+
+ // Build the lookup tables after all data have been read.
+ void
+ build_lookup_tables();
+
+ // Give an error if there are any unmatched names in the version
+ // script.
+ void
+ check_unmatched_names(const Symbol_table*) const;
+
+ // 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;
+
+ // Fast lookup information for a given language.
+
+ // We map from exact match strings to Version_tree's. Historically
+ // version scripts sometimes have the same symbol multiple times,
+ // which is ambiguous. We warn about that case by storing the
+ // second Version_tree we see.
+ struct Version_tree_match
+ {
+ Version_tree_match(const Version_tree* r, bool ig,
+ const Version_expression* e)
+ : real(r), is_global(ig), expression(e), ambiguous(NULL)
+ { }
+
+ // The Version_tree that we return.
+ const Version_tree* real;
+ // True if this is a global match for the REAL member, false if it
+ // is a local match.
+ bool is_global;
+ // Point back to the Version_expression for which we created this
+ // match.
+ const Version_expression* expression;
+ // If not NULL, another Version_tree that defines the symbol.
+ const Version_tree* ambiguous;
+ };
+
+ // Map from an exact match string to a Version_tree.
+
+ typedef Unordered_map<std::string, Version_tree_match> Exact;
+
+ // Fast lookup information for a glob pattern.
+ struct Glob
+ {
+ Glob()
+ : expression(NULL), version(NULL), is_global(false)
+ { }
+
+ Glob(const Version_expression* e, const Version_tree* v, bool ig)
+ : expression(e), version(v), is_global(ig)
+ { }
+
+ // A pointer to the version expression holding the pattern to
+ // match and the language to use for demangling the symbol before
+ // doing the match.
+ const Version_expression* expression;
+ // The Version_tree we use if this pattern matches.
+ const Version_tree* version;
+ // True if this is a global symbol.
+ bool is_global;
+ };
+
+ typedef std::vector<Glob> Globs;
+
+ bool
+ unquote(std::string*) const;
+
+ void
+ add_exact_match(const std::string&, const Version_tree*, bool is_global,
+ const Version_expression*, Exact*);
+
+ void
+ build_expression_list_lookup(const Version_expression_list*,
+ const Version_tree*, bool);
+
+ const char*
+ get_name_to_match(const char*, int,
+ Lazy_demangler*, Lazy_demangler*) const;
+
+ // All the version dependencies we allocate.
+ std::vector<Version_dependency_list*> dependency_lists_;
+ // All the version expressions we allocate.
+ std::vector<Version_expression_list*> expression_lists_;
+ // The list of versions.
+ std::vector<Version_tree*> version_trees_;
+ // Exact matches for global symbols, by language.
+ Exact* exact_[LANGUAGE_COUNT];
+ // A vector of glob patterns mapping to Version_trees.
+ Globs globs_;
+ // The default version to use, if there is one. This is from a
+ // pattern of "*".
+ const Version_tree* default_version_;
+ // True if the default version is global.
+ bool default_is_global_;
+ // Whether this has been finalized.
+ bool is_finalized_;
+};
+
+// 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*);
+
+ bool
+ is_defsym() const
+ { return is_defsym_; }
+
+ Expression *
+ value() const
+ { return val_; }
+
+ // 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 or relative to
+ // DOT_SECTION. 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, Output_section* dot_section);
+
+ const std::string&
+ name() const
+ { return this->name_; }
+
+ // 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);
+
+ // Look for an assigned symbol.
+ bool
+ is_pending_assignment(const char* name);
+
+ // Add a reference to a symbol.
+ void
+ add_symbol_reference(const char* name, size_t length);
+
+ // 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);
+
+ // Populates the set with symbol names used in LHS of defsym.
+ void
+ find_defsym_defs(Unordered_set<std::string>&);
+
+ // Set symbols used in defsym expressions as seen in a real ELF object.
+ void set_defsym_uses_in_real_elf(Symbol_table*) const;
+
+ // 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*);
+
+ // Used to iterate over symbols which are referenced in expressions
+ // but not defined.
+ typedef Unordered_set<std::string>::const_iterator referenced_const_iterator;
+
+ referenced_const_iterator
+ referenced_begin() const
+ { return this->symbol_references_.begin(); }
+
+ referenced_const_iterator
+ referenced_end() const
+ { return this->symbol_references_.end(); }
+
+ // Return whether a symbol is referenced but not defined.
+ bool
+ is_referenced(const std::string& name) const
+ {
+ return (this->symbol_references_.find(name)
+ != this->symbol_references_.end());
+ }
+
+ // Return whether there are any symbols which were referenced but
+ // not defined.
+ bool
+ any_unreferenced() const
+ { return !this->symbol_references_.empty(); }
+
+ // 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 which 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_;
+ // Symbols defined in an expression, for faster lookup.
+ Unordered_set<std::string> symbol_definitions_;
+ // Symbols referenced in an expression.
+ Unordered_set<std::string> symbol_references_;
+ // 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_;
+};
// 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. We've
-// already read BYTES of data into P. Return true if the file was
-// handled. This has to handle /usr/lib/libc.so on a GNU/Linux
-// system.
+// 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*, const General_options&, Symbol_table*, Layout*,
- Dirsearch*, Input_objects*, Input_group*,
- const Input_argument*, Input_file*, const unsigned char* p,
- off_t bytes, Task_token* this_blocker,
- Task_token* next_blocker);
+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*);
+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.
projects / deliverable / binutils-gdb.git / blobdiff