// script.cc -- handle linker scripts for gold.

// Copyright (C) 2006-2024 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <[email protected]>.

// 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.

#include "gold.h"

#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <fnmatch.h>
#include <string>
#include <vector>
#include "filenames.h"

#include "elfcpp.h"
#include "demangle.h"
#include "dirsearch.h"
#include "options.h"
#include "fileread.h"
#include "workqueue.h"
#include "readsyms.h"
#include "parameters.h"
#include "layout.h"
#include "symtab.h"
#include "target-select.h"
#include "script.h"
#include "script-c.h"
#include "incremental.h"

namespace gold
{

// A token read from a script file.  We don't implement keywords here;
// all keywords are simply represented as a string.

class Token
{
public:
 // Token classification.
 enum Classification
 {
   // Token is invalid.
   TOKEN_INVALID,
   // Token indicates end of input.
   TOKEN_EOF,
   // Token is a string of characters.
   TOKEN_STRING,
   // Token is a quoted string of characters.
   TOKEN_QUOTED_STRING,
   // Token is an operator.
   TOKEN_OPERATOR,
   // Token is a number (an integer).
   TOKEN_INTEGER
 };

 // We need an empty constructor so that we can put this STL objects.
 Token()
   : classification_(TOKEN_INVALID), value_(NULL), value_length_(0),
     opcode_(0), lineno_(0), charpos_(0)
 { }

 // A general token with no value.
 Token(Classification classification, int lineno, int charpos)
   : classification_(classification), value_(NULL), value_length_(0),
     opcode_(0), lineno_(lineno), charpos_(charpos)
 {
   gold_assert(classification == TOKEN_INVALID
               || classification == TOKEN_EOF);
 }

 // A general token with a value.
 Token(Classification classification, const char* value, size_t length,
       int lineno, int charpos)
   : classification_(classification), value_(value), value_length_(length),
     opcode_(0), lineno_(lineno), charpos_(charpos)
 {
   gold_assert(classification != TOKEN_INVALID
               && classification != TOKEN_EOF);
 }

 // A token representing an operator.
 Token(int opcode, int lineno, int charpos)
   : classification_(TOKEN_OPERATOR), value_(NULL), value_length_(0),
     opcode_(opcode), lineno_(lineno), charpos_(charpos)
 { }

 // Return whether the token is invalid.
 bool
 is_invalid() const
 { return this->classification_ == TOKEN_INVALID; }

 // Return whether this is an EOF token.
 bool
 is_eof() const
 { return this->classification_ == TOKEN_EOF; }

 // Return the token classification.
 Classification
 classification() const
 { return this->classification_; }

 // Return the line number at which the token starts.
 int
 lineno() const
 { return this->lineno_; }

 // Return the character position at this the token starts.
 int
 charpos() const
 { return this->charpos_; }

 // Get the value of a token.

 const char*
 string_value(size_t* length) const
 {
   gold_assert(this->classification_ == TOKEN_STRING
               || this->classification_ == TOKEN_QUOTED_STRING);
   *length = this->value_length_;
   return this->value_;
 }

 int
 operator_value() const
 {
   gold_assert(this->classification_ == TOKEN_OPERATOR);
   return this->opcode_;
 }

 uint64_t
 integer_value() const;

private:
 // The token classification.
 Classification classification_;
 // The token value, for TOKEN_STRING or TOKEN_QUOTED_STRING or
 // TOKEN_INTEGER.
 const char* value_;
 // The length of the token value.
 size_t value_length_;
 // The token value, for TOKEN_OPERATOR.
 int opcode_;
 // The line number where this token started (one based).
 int lineno_;
 // The character position within the line where this token started
 // (one based).
 int charpos_;
};

// Return the value of a TOKEN_INTEGER.

uint64_t
Token::integer_value() const
{
 gold_assert(this->classification_ == TOKEN_INTEGER);

 size_t len = this->value_length_;

 uint64_t multiplier = 1;
 char last = this->value_[len - 1];
 if (last == 'm' || last == 'M')
   {
     multiplier = 1024 * 1024;
     --len;
   }
 else if (last == 'k' || last == 'K')
   {
     multiplier = 1024;
     --len;
   }

 char *end;
 uint64_t ret = strtoull(this->value_, &end, 0);
 gold_assert(static_cast<size_t>(end - this->value_) == len);

 return ret * multiplier;
}

// This class handles lexing a file into a sequence of tokens.

class Lex
{
public:
 // We unfortunately have to support different lexing modes, because
 // when reading different parts of a linker script we need to parse
 // things differently.
 enum Mode
 {
   // Reading an ordinary linker script.
   LINKER_SCRIPT,
   // Reading an expression in a linker script.
   EXPRESSION,
   // Reading a version script.
   VERSION_SCRIPT,
   // Reading a --dynamic-list file.
   DYNAMIC_LIST
 };

 Lex(const char* input_string, size_t input_length, int parsing_token)
   : input_string_(input_string), input_length_(input_length),
     current_(input_string), mode_(LINKER_SCRIPT),
     first_token_(parsing_token), token_(),
     lineno_(1), linestart_(input_string)
 { }

 // Read a file into a string.
 static void
 read_file(Input_file*, std::string*);

 // Return the next token.
 const Token*
 next_token();

 // Return the current lexing mode.
 Lex::Mode
 mode() const
 { return this->mode_; }

 // Set the lexing mode.
 void
 set_mode(Mode mode)
 { this->mode_ = mode; }

private:
 Lex(const Lex&);
 Lex& operator=(const Lex&);

 // Make a general token with no value at the current location.
 Token
 make_token(Token::Classification c, const char* start) const
 { return Token(c, this->lineno_, start - this->linestart_ + 1); }

 // Make a general token with a value at the current location.
 Token
 make_token(Token::Classification c, const char* v, size_t len,
            const char* start)
   const
 { return Token(c, v, len, this->lineno_, start - this->linestart_ + 1); }

 // Make an operator token at the current location.
 Token
 make_token(int opcode, const char* start) const
 { return Token(opcode, this->lineno_, start - this->linestart_ + 1); }

 // Make an invalid token at the current location.
 Token
 make_invalid_token(const char* start)
 { return this->make_token(Token::TOKEN_INVALID, start); }

 // Make an EOF token at the current location.
 Token
 make_eof_token(const char* start)
 { return this->make_token(Token::TOKEN_EOF, start); }

 // Return whether C can be the first character in a name.  C2 is the
 // next character, since we sometimes need that.
 inline bool
 can_start_name(char c, char c2);

 // If C can appear in a name which has already started, return a
 // pointer to a character later in the token or just past
 // it. Otherwise, return NULL.
 inline const char*
 can_continue_name(const char* c);

 // Return whether C, C2, C3 can start a hex number.
 inline bool
 can_start_hex(char c, char c2, char c3);

 // If C can appear in a hex number which has already started, return
 // a pointer to a character later in the token or just past
 // it. Otherwise, return NULL.
 inline const char*
 can_continue_hex(const char* c);

 // Return whether C can start a non-hex number.
 static inline bool
 can_start_number(char c);

 // If C can appear in a decimal number which has already started,
 // return a pointer to a character later in the token or just past
 // it. Otherwise, return NULL.
 inline const char*
 can_continue_number(const char* c)
 { return Lex::can_start_number(*c) ? c + 1 : NULL; }

 // If C1 C2 C3 form a valid three character operator, return the
 // opcode.  Otherwise return 0.
 static inline int
 three_char_operator(char c1, char c2, char c3);

 // If C1 C2 form a valid two character operator, return the opcode.
 // Otherwise return 0.
 static inline int
 two_char_operator(char c1, char c2);

 // If C1 is a valid one character operator, return the opcode.
 // Otherwise return 0.
 static inline int
 one_char_operator(char c1);

 // Read the next token.
 Token
 get_token(const char**);

 // Skip a C style /* */ comment.  Return false if the comment did
 // not end.
 bool
 skip_c_comment(const char**);

 // Skip a line # comment.  Return false if there was no newline.
 bool
 skip_line_comment(const char**);

 // Build a token CLASSIFICATION from all characters that match
 // CAN_CONTINUE_FN.  The token starts at START.  Start matching from
 // MATCH.  Set *PP to the character following the token.
 inline Token
 gather_token(Token::Classification,
              const char* (Lex::*can_continue_fn)(const char*),
              const char* start, const char* match, const char** pp);

 // Build a token from a quoted string.
 Token
 gather_quoted_string(const char** pp);

 // The string we are tokenizing.
 const char* input_string_;
 // The length of the string.
 size_t input_length_;
 // The current offset into the string.
 const char* current_;
 // The current lexing mode.
 Mode mode_;
 // The code to use for the first token.  This is set to 0 after it
 // is used.
 int first_token_;
 // The current token.
 Token token_;
 // The current line number.
 int lineno_;
 // The start of the current line in the string.
 const char* linestart_;
};

// Read the whole file into memory.  We don't expect linker scripts to
// be large, so we just use a std::string as a buffer.  We ignore the
// data we've already read, so that we read aligned buffers.

void
Lex::read_file(Input_file* input_file, std::string* contents)
{
 off_t filesize = input_file->file().filesize();
 contents->clear();
 contents->reserve(filesize);

 off_t off = 0;
 unsigned char buf[BUFSIZ];
 while (off < filesize)
   {
     off_t get = BUFSIZ;
     if (get > filesize - off)
       get = filesize - off;
     input_file->file().read(off, get, buf);
     contents->append(reinterpret_cast<char*>(&buf[0]), get);
     off += get;
   }
}

// Return whether C can be the start of a name, if the next character
// is C2.  A name can being with a letter, underscore, period, or
// dollar sign.  Because a name can be a file name, we also permit
// forward slash, backslash, and tilde.  Tilde is the tricky case
// here; GNU ld also uses it as a bitwise not operator.  It is only
// recognized as the operator if it is not immediately followed by
// some character which can appear in a symbol.  That is, when we
// don't know that we are looking at an expression, "~0" is a file
// name, and "~ 0" is an expression using bitwise not.  We are
// compatible.

inline bool
Lex::can_start_name(char c, char c2)
{
 switch (c)
   {
   case 'A': case 'B': case 'C': case 'D': case 'E': case 'F':
   case 'G': case 'H': case 'I': case 'J': case 'K': case 'L':
   case 'M': case 'N': case 'O': case 'Q': case 'P': case 'R':
   case 'S': case 'T': case 'U': case 'V': case 'W': case 'X':
   case 'Y': case 'Z':
   case 'a': case 'b': case 'c': case 'd': case 'e': case 'f':
   case 'g': case 'h': case 'i': case 'j': case 'k': case 'l':
   case 'm': case 'n': case 'o': case 'q': case 'p': case 'r':
   case 's': case 't': case 'u': case 'v': case 'w': case 'x':
   case 'y': case 'z':
   case '_': case '.': case '$':
     return true;

   case '/': case '\\':
     return this->mode_ == LINKER_SCRIPT;

   case '~':
     return this->mode_ == LINKER_SCRIPT && can_continue_name(&c2);

   case '*': case '[':
     return (this->mode_ == VERSION_SCRIPT
             || this->mode_ == DYNAMIC_LIST
             || (this->mode_ == LINKER_SCRIPT
                 && can_continue_name(&c2)));

   default:
     return false;
   }
}

// Return whether C can continue a name which has already started.
// Subsequent characters in a name are the same as the leading
// characters, plus digits and "=+-:[],?*".  So in general the linker
// script language requires spaces around operators, unless we know
// that we are parsing an expression.

inline const char*
Lex::can_continue_name(const char* c)
{
 switch (*c)
   {
   case 'A': case 'B': case 'C': case 'D': case 'E': case 'F':
   case 'G': case 'H': case 'I': case 'J': case 'K': case 'L':
   case 'M': case 'N': case 'O': case 'Q': case 'P': case 'R':
   case 'S': case 'T': case 'U': case 'V': case 'W': case 'X':
   case 'Y': case 'Z':
   case 'a': case 'b': case 'c': case 'd': case 'e': case 'f':
   case 'g': case 'h': case 'i': case 'j': case 'k': case 'l':
   case 'm': case 'n': case 'o': case 'q': case 'p': case 'r':
   case 's': case 't': case 'u': case 'v': case 'w': case 'x':
   case 'y': case 'z':
   case '_': case '.': case '$':
   case '0': case '1': case '2': case '3': case '4':
   case '5': case '6': case '7': case '8': case '9':
     return c + 1;

   // TODO(csilvers): why not allow ~ in names for version-scripts?
   case '/': case '\\': case '~':
   case '=': case '+':
   case ',':
     if (this->mode_ == LINKER_SCRIPT)
       return c + 1;
     return NULL;

   case '[': case ']': case '*': case '?': case '-':
     if (this->mode_ == LINKER_SCRIPT || this->mode_ == VERSION_SCRIPT
         || this->mode_ == DYNAMIC_LIST)
       return c + 1;
     return NULL;

   // TODO(csilvers): why allow this?  ^ is meaningless in version scripts.
   case '^':
     if (this->mode_ == VERSION_SCRIPT || this->mode_ == DYNAMIC_LIST)
       return c + 1;
     return NULL;

   case ':':
     if (this->mode_ == LINKER_SCRIPT)
       return c + 1;
     else if ((this->mode_ == VERSION_SCRIPT || this->mode_ == DYNAMIC_LIST)
              && (c[1] == ':'))
       {
         // A name can have '::' in it, as that's a c++ namespace
         // separator. But a single colon is not part of a name.
         return c + 2;
       }
     return NULL;

   default:
     return NULL;
   }
}

// For a number we accept 0x followed by hex digits, or any sequence
// of digits.  The old linker accepts leading '$' for hex, and
// trailing HXBOD.  Those are for MRI compatibility and we don't
// accept them.

// Return whether C1 C2 C3 can start a hex number.

inline bool
Lex::can_start_hex(char c1, char c2, char c3)
{
 if (c1 == '0' && (c2 == 'x' || c2 == 'X'))
   return this->can_continue_hex(&c3);
 return false;
}

// Return whether C can appear in a hex number.

inline const char*
Lex::can_continue_hex(const char* c)
{
 switch (*c)
   {
   case '0': case '1': case '2': case '3': case '4':
   case '5': case '6': case '7': case '8': case '9':
   case 'A': case 'B': case 'C': case 'D': case 'E': case 'F':
   case 'a': case 'b': case 'c': case 'd': case 'e': case 'f':
     return c + 1;

   default:
     return NULL;
   }
}

// Return whether C can start a non-hex number.

inline bool
Lex::can_start_number(char c)
{
 switch (c)
   {
   case '0': case '1': case '2': case '3': case '4':
   case '5': case '6': case '7': case '8': case '9':
     return true;

   default:
     return false;
   }
}

// If C1 C2 C3 form a valid three character operator, return the
// opcode (defined in the yyscript.h file generated from yyscript.y).
// Otherwise return 0.

inline int
Lex::three_char_operator(char c1, char c2, char c3)
{
 switch (c1)
   {
   case '<':
     if (c2 == '<' && c3 == '=')
       return LSHIFTEQ;
     break;
   case '>':
     if (c2 == '>' && c3 == '=')
       return RSHIFTEQ;
     break;
   default:
     break;
   }
 return 0;
}

// If C1 C2 form a valid two character operator, return the opcode
// (defined in the yyscript.h file generated from yyscript.y).
// Otherwise return 0.

inline int
Lex::two_char_operator(char c1, char c2)
{
 switch (c1)
   {
   case '=':
     if (c2 == '=')
       return EQ;
     break;
   case '!':
     if (c2 == '=')
       return NE;
     break;
   case '+':
     if (c2 == '=')
       return PLUSEQ;
     break;
   case '-':
     if (c2 == '=')
       return MINUSEQ;
     break;
   case '*':
     if (c2 == '=')
       return MULTEQ;
     break;
   case '/':
     if (c2 == '=')
       return DIVEQ;
     break;
   case '|':
     if (c2 == '=')
       return OREQ;
     if (c2 == '|')
       return OROR;
     break;
   case '&':
     if (c2 == '=')
       return ANDEQ;
     if (c2 == '&')
       return ANDAND;
     break;
   case '>':
     if (c2 == '=')
       return GE;
     if (c2 == '>')
       return RSHIFT;
     break;
   case '<':
     if (c2 == '=')
       return LE;
     if (c2 == '<')
       return LSHIFT;
     break;
   default:
     break;
   }
 return 0;
}

// If C1 is a valid operator, return the opcode.  Otherwise return 0.

inline int
Lex::one_char_operator(char c1)
{
 switch (c1)
   {
   case '+':
   case '-':
   case '*':
   case '/':
   case '%':
   case '!':
   case '&':
   case '|':
   case '^':
   case '~':
   case '<':
   case '>':
   case '=':
   case '?':
   case ',':
   case '(':
   case ')':
   case '{':
   case '}':
   case '[':
   case ']':
   case ':':
   case ';':
     return c1;
   default:
     return 0;
   }
}

// Skip a C style comment.  *PP points to just after the "/*".  Return
// false if the comment did not end.

bool
Lex::skip_c_comment(const char** pp)
{
 const char* p = *pp;
 while (p[0] != '*' || p[1] != '/')
   {
     if (*p == '\0')
       {
         *pp = p;
         return false;
       }

     if (*p == '\n')
       {
         ++this->lineno_;
         this->linestart_ = p + 1;
       }
     ++p;
   }

 *pp = p + 2;
 return true;
}

// Skip a line # comment.  Return false if there was no newline.

bool
Lex::skip_line_comment(const char** pp)
{
 const char* p = *pp;
 size_t skip = strcspn(p, "\n");
 if (p[skip] == '\0')
   {
     *pp = p + skip;
     return false;
   }

 p += skip + 1;
 ++this->lineno_;
 this->linestart_ = p;
 *pp = p;

 return true;
}

// Build a token CLASSIFICATION from all characters that match
// CAN_CONTINUE_FN.  Update *PP.

inline Token
Lex::gather_token(Token::Classification classification,
                 const char* (Lex::*can_continue_fn)(const char*),
                 const char* start,
                 const char* match,
                 const char** pp)
{
 const char* new_match = NULL;
 while ((new_match = (this->*can_continue_fn)(match)) != NULL)
   match = new_match;

 // A special case: integers may be followed by a single M or K,
 // case-insensitive.
 if (classification == Token::TOKEN_INTEGER
     && (*match == 'm' || *match == 'M' || *match == 'k' || *match == 'K'))
   ++match;

 *pp = match;
 return this->make_token(classification, start, match - start, start);
}

// Build a token from a quoted string.

Token
Lex::gather_quoted_string(const char** pp)
{
 const char* start = *pp;
 const char* p = start;
 ++p;
 size_t skip = strcspn(p, "\"\n");
 if (p[skip] != '"')
   return this->make_invalid_token(start);
 *pp = p + skip + 1;
 return this->make_token(Token::TOKEN_QUOTED_STRING, p, skip, start);
}

// Return the next token at *PP.  Update *PP.  General guideline: we
// require linker scripts to be simple ASCII.  No unicode linker
// scripts.  In particular we can assume that any '\0' is the end of
// the input.

Token
Lex::get_token(const char** pp)
{
 const char* p = *pp;

 while (true)
   {
     // Skip whitespace quickly.
     while (*p == ' ' || *p == '\t' || *p == '\r')
       ++p;

     if (*p == '\n')
       {
         ++p;
         ++this->lineno_;
         this->linestart_ = p;
         continue;
       }

     char c0 = *p;

     if (c0 == '\0')
       {
         *pp = p;
         return this->make_eof_token(p);
       }

     char c1 = p[1];

     // Skip C style comments.
     if (c0 == '/' && c1 == '*')
       {
         int lineno = this->lineno_;
         int charpos = p - this->linestart_ + 1;

         *pp = p + 2;
         if (!this->skip_c_comment(pp))
           return Token(Token::TOKEN_INVALID, lineno, charpos);
         p = *pp;

         continue;
       }

     // Skip line comments.
     if (c0 == '#')
       {
         *pp = p + 1;
         if (!this->skip_line_comment(pp))
           return this->make_eof_token(p);
         p = *pp;
         continue;
       }

     // Check for a name.
     if (this->can_start_name(c0, c1))
       return this->gather_token(Token::TOKEN_STRING,
                                 &Lex::can_continue_name,
                                 p, p + 1, pp);

     // We accept any arbitrary name in double quotes, as long as it
     // does not cross a line boundary.
     if (*p == '"')
       {
         *pp = p;
         return this->gather_quoted_string(pp);
       }

     // Be careful not to lookahead past the end of the buffer.
     char c2 = (c1 == '\0' ? '\0' : p[2]);

     // Check for a number.

     if (this->can_start_hex(c0, c1, c2))
       return this->gather_token(Token::TOKEN_INTEGER,
                                 &Lex::can_continue_hex,
                                 p, p + 3, pp);

     if (Lex::can_start_number(c0))
       return this->gather_token(Token::TOKEN_INTEGER,
                                 &Lex::can_continue_number,
                                 p, p + 1, pp);

     // Check for operators.

     int opcode = Lex::three_char_operator(c0, c1, c2);
     if (opcode != 0)
       {
         *pp = p + 3;
         return this->make_token(opcode, p);
       }

     opcode = Lex::two_char_operator(c0, c1);
     if (opcode != 0)
       {
         *pp = p + 2;
         return this->make_token(opcode, p);
       }

     opcode = Lex::one_char_operator(c0);
     if (opcode != 0)
       {
         *pp = p + 1;
         return this->make_token(opcode, p);
       }

     return this->make_token(Token::TOKEN_INVALID, p);
   }
}

// Return the next token.

const Token*
Lex::next_token()
{
 // The first token is special.
 if (this->first_token_ != 0)
   {
     this->token_ = Token(this->first_token_, 0, 0);
     this->first_token_ = 0;
     return &this->token_;
   }

 this->token_ = this->get_token(&this->current_);

 // Don't let an early null byte fool us into thinking that we've
 // reached the end of the file.
 if (this->token_.is_eof()
     && (static_cast<size_t>(this->current_ - this->input_string_)
         < this->input_length_))
   this->token_ = this->make_invalid_token(this->current_);

 return &this->token_;
}

// class Symbol_assignment.

// Add the symbol to the symbol table.  This makes sure the symbol is
// there and defined.  The actual value is stored later.  We can't
// determine the actual value at this point, because we can't
// necessarily evaluate the expression until all ordinary symbols have
// been finalized.

// The GNU linker lets symbol assignments in the linker script
// silently override defined symbols in object files.  We are
// compatible.  FIXME: Should we issue a warning?

void
Symbol_assignment::add_to_table(Symbol_table* symtab)
{
 elfcpp::STV vis = this->hidden_ ? elfcpp::STV_HIDDEN : elfcpp::STV_DEFAULT;
 this->sym_ = symtab->define_as_constant(this->name_.c_str(),
                                         NULL, // version
                                         (this->is_defsym_
                                          ? Symbol_table::DEFSYM
                                          : Symbol_table::SCRIPT),
                                         0, // value
                                         0, // size
                                         elfcpp::STT_NOTYPE,
                                         elfcpp::STB_GLOBAL,
                                         vis,
                                         0, // nonvis
                                         this->provide_,
                                         true); // force_override
}

// Finalize a symbol value.

void
Symbol_assignment::finalize(Symbol_table* symtab, const Layout* layout)
{
 this->finalize_maybe_dot(symtab, layout, false, 0, NULL);
}

// Finalize a symbol value which can refer to the dot symbol.

void
Symbol_assignment::finalize_with_dot(Symbol_table* symtab,
                                    const Layout* layout,
                                    uint64_t dot_value,
                                    Output_section* dot_section)
{
 this->finalize_maybe_dot(symtab, layout, true, dot_value, dot_section);
}

// Finalize a symbol value, internal version.

void
Symbol_assignment::finalize_maybe_dot(Symbol_table* symtab,
                                     const Layout* layout,
                                     bool is_dot_available,
                                     uint64_t dot_value,
                                     Output_section* dot_section)
{
 // If we were only supposed to provide this symbol, the sym_ field
 // will be NULL if the symbol was not referenced.
 if (this->sym_ == NULL)
   {
     gold_assert(this->provide_);
     return;
   }

 if (parameters->target().get_size() == 32)
   {
#if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
     this->sized_finalize<32>(symtab, layout, is_dot_available, dot_value,
                              dot_section);
#else
     gold_unreachable();
#endif
   }
 else if (parameters->target().get_size() == 64)
   {
#if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
     this->sized_finalize<64>(symtab, layout, is_dot_available, dot_value,
                              dot_section);
#else
     gold_unreachable();
#endif
   }
 else
   gold_unreachable();
}

template<int size>
void
Symbol_assignment::sized_finalize(Symbol_table* symtab, const Layout* layout,
                                 bool is_dot_available, uint64_t dot_value,
                                 Output_section* dot_section)
{
 Output_section* section;
 elfcpp::STT type = elfcpp::STT_NOTYPE;
 elfcpp::STV vis = elfcpp::STV_DEFAULT;
 unsigned char nonvis = 0;
 uint64_t final_val = this->val_->eval_maybe_dot(symtab, layout, true,
                                                 is_dot_available,
                                                 dot_value, dot_section,
                                                 &section, NULL, &type,
                                                 &vis, &nonvis, false, NULL);
 Sized_symbol<size>* ssym = symtab->get_sized_symbol<size>(this->sym_);
 ssym->set_value(final_val);
 ssym->set_type(type);
 ssym->set_visibility(vis);
 ssym->set_nonvis(nonvis);
 if (section != NULL)
   ssym->set_output_section(section);
}

// Set the symbol value if the expression yields an absolute value or
// a value relative to DOT_SECTION.

void
Symbol_assignment::set_if_absolute(Symbol_table* symtab, const Layout* layout,
                                  bool is_dot_available, uint64_t dot_value,
                                  Output_section* dot_section)
{
 if (this->sym_ == NULL)
   return;

 Output_section* val_section;
 bool is_valid;
 uint64_t val = this->val_->eval_maybe_dot(symtab, layout, false,
                                           is_dot_available, dot_value,
                                           dot_section, &val_section, NULL,
                                           NULL, NULL, NULL, false, &is_valid);
 if (!is_valid || (val_section != NULL && val_section != dot_section))
   return;

 if (parameters->target().get_size() == 32)
   {
#if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
     Sized_symbol<32>* ssym = symtab->get_sized_symbol<32>(this->sym_);
     ssym->set_value(val);
#else
     gold_unreachable();
#endif
   }
 else if (parameters->target().get_size() == 64)
   {
#if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
     Sized_symbol<64>* ssym = symtab->get_sized_symbol<64>(this->sym_);
     ssym->set_value(val);
#else
     gold_unreachable();
#endif
   }
 else
   gold_unreachable();
 if (val_section != NULL)
   this->sym_->set_output_section(val_section);
}

// Print for debugging.

void
Symbol_assignment::print(FILE* f) const
{
 if (this->provide_ && this->hidden_)
   fprintf(f, "PROVIDE_HIDDEN(");
 else if (this->provide_)
   fprintf(f, "PROVIDE(");
 else if (this->hidden_)
   gold_unreachable();

 fprintf(f, "%s = ", this->name_.c_str());
 this->val_->print(f);

 if (this->provide_ || this->hidden_)
   fprintf(f, ")");

 fprintf(f, "\n");
}

// Class Script_assertion.

// Check the assertion.

void
Script_assertion::check(const Symbol_table* symtab, const Layout* layout)
{
 if (!this->check_->eval(symtab, layout, true))
   gold_error("%s", this->message_.c_str());
}

// Print for debugging.

void
Script_assertion::print(FILE* f) const
{
 fprintf(f, "ASSERT(");
 this->check_->print(f);
 fprintf(f, ", \"%s\")\n", this->message_.c_str());
}

// Class Script_options.

Script_options::Script_options()
 : entry_(), symbol_assignments_(), symbol_definitions_(),
   symbol_references_(), version_script_info_(), script_sections_()
{
}

// Returns true if NAME is on the list of symbol assignments waiting
// to be processed.

bool
Script_options::is_pending_assignment(const char* name)
{
 for (Symbol_assignments::iterator p = this->symbol_assignments_.begin();
      p != this->symbol_assignments_.end();
      ++p)
   if ((*p)->name() == name)
     return true;
 return false;
}

// Populates the set with symbols defined in defsym LHS.

void Script_options::find_defsym_defs(Unordered_set<std::string>& defsym_set)
{
 for (Symbol_assignments::const_iterator p = this->symbol_assignments_.begin();
      p != this->symbol_assignments_.end();
      ++p)
   {
     defsym_set.insert((*p)->name());
   }
}

void
Script_options::set_defsym_uses_in_real_elf(Symbol_table* symtab) const
{
 for (Symbol_assignments::const_iterator p = this->symbol_assignments_.begin();
      p != this->symbol_assignments_.end();
      ++p)
   {
     (*p)->value()->set_expr_sym_in_real_elf(symtab);
   }
}

// Add a symbol to be defined.

void
Script_options::add_symbol_assignment(const char* name, size_t length,
                                     bool is_defsym, Expression* value,
                                     bool provide, bool hidden)
{
 if (length != 1 || name[0] != '.')
   {
     if (this->script_sections_.in_sections_clause())
       {
         gold_assert(!is_defsym);
         this->script_sections_.add_symbol_assignment(name, length, value,
                                                      provide, hidden);
       }
     else
       {
         Symbol_assignment* p = new Symbol_assignment(name, length, is_defsym,
                                                      value, provide, hidden);
         this->symbol_assignments_.push_back(p);
       }

     if (!provide)
       {
         std::string n(name, length);
         this->symbol_definitions_.insert(n);
         this->symbol_references_.erase(n);
       }
   }
 else
   {
     if (provide || hidden)
       gold_error(_("invalid use of PROVIDE for dot symbol"));

     // The GNU linker permits assignments to dot outside of SECTIONS
     // clauses and treats them as occurring inside, so we don't
     // check in_sections_clause here.
     this->script_sections_.add_dot_assignment(value);
   }
}

// Add a reference to a symbol.

void
Script_options::add_symbol_reference(const char* name, size_t length)
{
 if (length != 1 || name[0] != '.')
   {
     std::string n(name, length);
     if (this->symbol_definitions_.find(n) == this->symbol_definitions_.end())
       this->symbol_references_.insert(n);
   }
}

// Add an assertion.

void
Script_options::add_assertion(Expression* check, const char* message,
                             size_t messagelen)
{
 if (this->script_sections_.in_sections_clause())
   this->script_sections_.add_assertion(check, message, messagelen);
 else
   {
     Script_assertion* p = new Script_assertion(check, message, messagelen);
     this->assertions_.push_back(p);
   }
}

// Create sections required by any linker scripts.

void
Script_options::create_script_sections(Layout* layout)
{
 if (this->saw_sections_clause())
   this->script_sections_.create_sections(layout);
}

// Add any symbols we are defining to the symbol table.

void
Script_options::add_symbols_to_table(Symbol_table* symtab)
{
 for (Symbol_assignments::iterator p = this->symbol_assignments_.begin();
      p != this->symbol_assignments_.end();
      ++p)
   (*p)->add_to_table(symtab);
 this->script_sections_.add_symbols_to_table(symtab);
}

// Finalize symbol values.  Also check assertions.

void
Script_options::finalize_symbols(Symbol_table* symtab, const Layout* layout)
{
 // We finalize the symbols defined in SECTIONS first, because they
 // are the ones which may have changed.  This way if symbol outside
 // SECTIONS are defined in terms of symbols inside SECTIONS, they
 // will get the right value.
 this->script_sections_.finalize_symbols(symtab, layout);

 for (Symbol_assignments::iterator p = this->symbol_assignments_.begin();
      p != this->symbol_assignments_.end();
      ++p)
   (*p)->finalize(symtab, layout);

 for (Assertions::iterator p = this->assertions_.begin();
      p != this->assertions_.end();
      ++p)
   (*p)->check(symtab, layout);
}

// Set section addresses.  We set all the symbols which have absolute
// values.  Then we let the SECTIONS clause do its thing.  This
// returns the segment which holds the file header and segment
// headers, if any.

Output_segment*
Script_options::set_section_addresses(Symbol_table* symtab, Layout* layout)
{
 for (Symbol_assignments::iterator p = this->symbol_assignments_.begin();
      p != this->symbol_assignments_.end();
      ++p)
   (*p)->set_if_absolute(symtab, layout, false, 0, NULL);

 return this->script_sections_.set_section_addresses(symtab, layout);
}

// This class holds data passed through the parser to the lexer and to
// the parser support functions.  This avoids global variables.  We
// can't use global variables because we need not be called by a
// singleton thread.

class Parser_closure
{
public:
 Parser_closure(const char* filename,
                const Position_dependent_options& posdep_options,
                bool parsing_defsym, bool in_group, bool is_in_sysroot,
                Command_line* command_line,
                Script_options* script_options,
                Lex* lex,
                bool skip_on_incompatible_target,
                Script_info* script_info)
   : filename_(filename), posdep_options_(posdep_options),
     parsing_defsym_(parsing_defsym), in_group_(in_group),
     is_in_sysroot_(is_in_sysroot),
     skip_on_incompatible_target_(skip_on_incompatible_target),
     found_incompatible_target_(false),
     command_line_(command_line), script_options_(script_options),
     version_script_info_(script_options->version_script_info()),
     lex_(lex), lineno_(0), charpos_(0), lex_mode_stack_(), inputs_(NULL),
     script_info_(script_info)
 {
   // We start out processing C symbols in the default lex mode.
   this->language_stack_.push_back(Version_script_info::LANGUAGE_C);
   this->lex_mode_stack_.push_back(lex->mode());
 }

 // Return the file name.
 const char*
 filename() const
 { return this->filename_; }

 // Return the position dependent options.  The caller may modify
 // this.
 Position_dependent_options&
 position_dependent_options()
 { return this->posdep_options_; }

 // Whether we are parsing a --defsym.
 bool
 parsing_defsym() const
 { return this->parsing_defsym_; }

 // Return whether this script is being run in a group.
 bool
 in_group() const
 { return this->in_group_; }

 // Return whether this script was found using a directory in the
 // sysroot.
 bool
 is_in_sysroot() const
 { return this->is_in_sysroot_; }

 // Whether to skip to the next file with the same name if we find an
 // incompatible target in an OUTPUT_FORMAT statement.
 bool
 skip_on_incompatible_target() const
 { return this->skip_on_incompatible_target_; }

 // Stop skipping to the next file on an incompatible target.  This
 // is called when we make some unrevocable change to the data
 // structures.
 void
 clear_skip_on_incompatible_target()
 { this->skip_on_incompatible_target_ = false; }

 // Whether we found an incompatible target in an OUTPUT_FORMAT
 // statement.
 bool
 found_incompatible_target() const
 { return this->found_incompatible_target_; }

 // Note that we found an incompatible target.
 void
 set_found_incompatible_target()
 { this->found_incompatible_target_ = true; }

 // Returns the Command_line structure passed in at constructor time.
 // This value may be NULL.  The caller may modify this, which modifies
 // the passed-in Command_line object (not a copy).
 Command_line*
 command_line()
 { return this->command_line_; }

 // Return the options which may be set by a script.
 Script_options*
 script_options()
 { return this->script_options_; }

 // Return the object in which version script information should be stored.
 Version_script_info*
 version_script()
 { return this->version_script_info_; }

 // Return the next token, and advance.
 const Token*
 next_token()
 {
   const Token* token = this->lex_->next_token();
   this->lineno_ = token->lineno();
   this->charpos_ = token->charpos();
   return token;
 }

 // Set a new lexer mode, pushing the current one.
 void
 push_lex_mode(Lex::Mode mode)
 {
   this->lex_mode_stack_.push_back(this->lex_->mode());
   this->lex_->set_mode(mode);
 }

 // Pop the lexer mode.
 void
 pop_lex_mode()
 {
   gold_assert(!this->lex_mode_stack_.empty());
   this->lex_->set_mode(this->lex_mode_stack_.back());
   this->lex_mode_stack_.pop_back();
 }

 // Return the current lexer mode.
 Lex::Mode
 lex_mode() const
 { return this->lex_mode_stack_.back(); }

 // Return the line number of the last token.
 int
 lineno() const
 { return this->lineno_; }

 // Return the character position in the line of the last token.
 int
 charpos() const
 { return this->charpos_; }

 // Return the list of input files, creating it if necessary.  This
 // is a space leak--we never free the INPUTS_ pointer.
 Input_arguments*
 inputs()
 {
   if (this->inputs_ == NULL)
     this->inputs_ = new Input_arguments();
   return this->inputs_;
 }

 // Return whether we saw any input files.
 bool
 saw_inputs() const
 { return this->inputs_ != NULL && !this->inputs_->empty(); }

 // Return the current language being processed in a version script
 // (eg, "C++").  The empty string represents unmangled C names.
 Version_script_info::Language
 get_current_language() const
 { return this->language_stack_.back(); }

 // Push a language onto the stack when entering an extern block.
 void
 push_language(Version_script_info::Language lang)
 { this->language_stack_.push_back(lang); }

 // Pop a language off of the stack when exiting an extern block.
 void
 pop_language()
 {
   gold_assert(!this->language_stack_.empty());
   this->language_stack_.pop_back();
 }

 // Return a pointer to the incremental info.
 Script_info*
 script_info()
 { return this->script_info_; }

private:
 // The name of the file we are reading.
 const char* filename_;
 // The position dependent options.
 Position_dependent_options posdep_options_;
 // True if we are parsing a --defsym.
 bool parsing_defsym_;
 // Whether we are currently in a --start-group/--end-group.
 bool in_group_;
 // Whether the script was found in a sysrooted directory.
 bool is_in_sysroot_;
 // If this is true, then if we find an OUTPUT_FORMAT with an
 // incompatible target, then we tell the parser to abort so that we
 // can search for the next file with the same name.
 bool skip_on_incompatible_target_;
 // True if we found an OUTPUT_FORMAT with an incompatible target.
 bool found_incompatible_target_;
 // May be NULL if the user chooses not to pass one in.
 Command_line* command_line_;
 // Options which may be set from any linker script.
 Script_options* script_options_;
 // Information parsed from a version script.
 Version_script_info* version_script_info_;
 // The lexer.
 Lex* lex_;
 // The line number of the last token returned by next_token.
 int lineno_;
 // The column number of the last token returned by next_token.
 int charpos_;
 // A stack of lexer modes.
 std::vector<Lex::Mode> lex_mode_stack_;
 // A stack of which extern/language block we're inside. Can be C++,
 // java, or empty for C.
 std::vector<Version_script_info::Language> language_stack_;
 // New input files found to add to the link.
 Input_arguments* inputs_;
 // Pointer to incremental linking info.
 Script_info* script_info_;
};

// FILE was found as an argument on the command line.  Try to read it
// as a script.  Return true if the file was handled.

bool
read_input_script(Workqueue* workqueue, Symbol_table* symtab, Layout* layout,
                 Dirsearch* dirsearch, int dirindex,
                 Input_objects* input_objects, Mapfile* mapfile,
                 Input_group* input_group,
                 const Input_argument* input_argument,
                 Input_file* input_file, Task_token* next_blocker,
                 bool* used_next_blocker)
{
 *used_next_blocker = false;

 std::string input_string;
 Lex::read_file(input_file, &input_string);

 Lex lex(input_string.c_str(), input_string.length(), PARSING_LINKER_SCRIPT);

 Script_info* script_info = NULL;
 if (layout->incremental_inputs() != NULL)
   {
     const std::string& filename = input_file->filename();
     Timespec mtime = input_file->file().get_mtime();
     unsigned int arg_serial = input_argument->file().arg_serial();
     script_info = new Script_info(filename);
     layout->incremental_inputs()->report_script(script_info, arg_serial,
                                                 mtime);
   }

 Parser_closure closure(input_file->filename().c_str(),
                        input_argument->file().options(),
                        false,
                        input_group != NULL,
                        input_file->is_in_sysroot(),
                        NULL,
                        layout->script_options(),
                        &lex,
                        input_file->will_search_for(),
                        script_info);

 bool old_saw_sections_clause =
   layout->script_options()->saw_sections_clause();

 if (yyparse(&closure) != 0)
   {
     if (closure.found_incompatible_target())
       {
         Read_symbols::incompatible_warning(input_argument, input_file);
         Read_symbols::requeue(workqueue, input_objects, symtab, layout,
                               dirsearch, dirindex, mapfile, input_argument,
                               input_group, next_blocker);
         return true;
       }
     return false;
   }

 if (!old_saw_sections_clause
     && layout->script_options()->saw_sections_clause()
     && layout->have_added_input_section())
   gold_error(_("%s: SECTIONS seen after other input files; try -T/--script"),
              input_file->filename().c_str());

 if (!closure.saw_inputs())
   return true;

 Task_token* this_blocker = NULL;
 for (Input_arguments::const_iterator p = closure.inputs()->begin();
      p != closure.inputs()->end();
      ++p)
   {
     Task_token* nb;
     if (p + 1 == closure.inputs()->end())
       nb = next_blocker;
     else
       {
         nb = new Task_token(true);
         nb->add_blocker();
       }
     workqueue->queue_soon(new Read_symbols(input_objects, symtab,
                                            layout, dirsearch, 0, mapfile, &*p,
                                            input_group, NULL, this_blocker, nb));
     this_blocker = nb;
   }

 *used_next_blocker = true;

 return true;
}

// Helper function for read_version_script(), read_commandline_script() and
// script_include_directive().  Processes the given file in the mode indicated
// by first_token and lex_mode.

static bool
read_script_file(const char* filename, Command_line* cmdline,
                Script_options* script_options,
                int first_token, Lex::Mode lex_mode)
{
 Dirsearch dirsearch;
 std::string name = filename;

 // If filename is a relative filename, search for it manually using "." +
 // cmdline->options()->library_path() -- not dirsearch.
 if (!IS_ABSOLUTE_PATH(filename))
   {
     const General_options::Dir_list& search_path =
         cmdline->options().library_path();
     name = Dirsearch::find_file_in_dir_list(name, search_path, ".");
   }

 // The file locking code wants to record a Task, but we haven't
 // started the workqueue yet.  This is only for debugging purposes,
 // so we invent a fake value.
 const Task* task = reinterpret_cast<const Task*>(-1);

 // We don't want this file to be opened in binary mode.
 Position_dependent_options posdep = cmdline->position_dependent_options();
 if (posdep.format_enum() == General_options::OBJECT_FORMAT_BINARY)
   posdep.set_format_enum(General_options::OBJECT_FORMAT_ELF);
 Input_file_argument input_argument(name.c_str(),
                                    Input_file_argument::INPUT_FILE_TYPE_FILE,
                                    "", false, posdep);
 Input_file input_file(&input_argument);
 int dummy = 0;
 if (!input_file.open(dirsearch, task, &dummy))
   return false;

 std::string input_string;
 Lex::read_file(&input_file, &input_string);

 Lex lex(input_string.c_str(), input_string.length(), first_token);
 lex.set_mode(lex_mode);

 Parser_closure closure(filename,
                        cmdline->position_dependent_options(),
                        first_token == Lex::DYNAMIC_LIST,
                        false,
                        input_file.is_in_sysroot(),
                        cmdline,
                        script_options,
                        &lex,
                        false,
                        NULL);
 if (yyparse(&closure) != 0)
   {
     input_file.file().unlock(task);
     return false;
   }

 input_file.file().unlock(task);

 gold_assert(!closure.saw_inputs());

 return true;
}

// FILENAME 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)
{
 return read_script_file(filename, cmdline, &cmdline->script_options(),
                         PARSING_LINKER_SCRIPT, Lex::LINKER_SCRIPT);
}

// FILENAME 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)
{
 return read_script_file(filename, cmdline, &cmdline->script_options(),
                         PARSING_VERSION_SCRIPT, Lex::VERSION_SCRIPT);
}

// FILENAME was found as an argument to --dynamic-list.  Read it as a
// list of symbols, and store its contents in DYNAMIC_LIST.

bool
read_dynamic_list(const char* filename, Command_line* cmdline,
                 Script_options* dynamic_list)
{
 return read_script_file(filename, cmdline, dynamic_list,
                         PARSING_DYNAMIC_LIST, Lex::DYNAMIC_LIST);
}

// Implement the --defsym option on the command line.  Return true if
// all is well.

bool
Script_options::define_symbol(const char* definition)
{
 Lex lex(definition, strlen(definition), PARSING_DEFSYM);
 lex.set_mode(Lex::EXPRESSION);

 // Dummy value.
 Position_dependent_options posdep_options;

 Parser_closure closure("command line", posdep_options, true,
                        false, false, NULL, this, &lex, false, NULL);

 if (yyparse(&closure) != 0)
   return false;

 gold_assert(!closure.saw_inputs());

 return true;
}

// Print the script to F for debugging.

void
Script_options::print(FILE* f) const
{
 fprintf(f, "%s: Dumping linker script\n", program_name);

 if (!this->entry_.empty())
   fprintf(f, "ENTRY(%s)\n", this->entry_.c_str());

 for (Symbol_assignments::const_iterator p =
        this->symbol_assignments_.begin();
      p != this->symbol_assignments_.end();
      ++p)
   (*p)->print(f);

 for (Assertions::const_iterator p = this->assertions_.begin();
      p != this->assertions_.end();
      ++p)
   (*p)->print(f);

 this->script_sections_.print(f);

 this->version_script_info_.print(f);
}

// Manage mapping from keywords to the codes expected by the bison
// parser.  We construct one global object for each lex mode with
// keywords.

class Keyword_to_parsecode
{
public:
 // The structure which maps keywords to parsecodes.
 struct Keyword_parsecode
 {
   // Keyword.
   const char* keyword;
   // Corresponding parsecode.
   int parsecode;
 };

 Keyword_to_parsecode(const Keyword_parsecode* keywords,
                      int keyword_count)
     : keyword_parsecodes_(keywords), keyword_count_(keyword_count)
 { }

 // Return the parsecode corresponding KEYWORD, or 0 if it is not a
 // keyword.
 int
 keyword_to_parsecode(const char* keyword, size_t len) const;

private:
 const Keyword_parsecode* keyword_parsecodes_;
 const int keyword_count_;
};

// Mapping from keyword string to keyword parsecode.  This array must
// be kept in sorted order.  Parsecodes are looked up using bsearch.
// This array must correspond to the list of parsecodes in yyscript.y.

static const Keyword_to_parsecode::Keyword_parsecode
script_keyword_parsecodes[] =
{
 { "ABSOLUTE", ABSOLUTE },
 { "ADDR", ADDR },
 { "ALIGN", ALIGN_K },
 { "ALIGNOF", ALIGNOF },
 { "ASSERT", ASSERT_K },
 { "AS_NEEDED", AS_NEEDED },
 { "AT", AT },
 { "BIND", BIND },
 { "BLOCK", BLOCK },
 { "BYTE", BYTE },
 { "CONSTANT", CONSTANT },
 { "CONSTRUCTORS", CONSTRUCTORS },
 { "COPY", COPY },
 { "CREATE_OBJECT_SYMBOLS", CREATE_OBJECT_SYMBOLS },
 { "DATA_SEGMENT_ALIGN", DATA_SEGMENT_ALIGN },
 { "DATA_SEGMENT_END", DATA_SEGMENT_END },
 { "DATA_SEGMENT_RELRO_END", DATA_SEGMENT_RELRO_END },
 { "DEFINED", DEFINED },
 { "DSECT", DSECT },
 { "ENTRY", ENTRY },
 { "EXCLUDE_FILE", EXCLUDE_FILE },
 { "EXTERN", EXTERN },
 { "FILL", FILL },
 { "FLOAT", FLOAT },
 { "FORCE_COMMON_ALLOCATION", FORCE_COMMON_ALLOCATION },
 { "GROUP", GROUP },
 { "HIDDEN", HIDDEN },
 { "HLL", HLL },
 { "INCLUDE", INCLUDE },
 { "INFO", INFO },
 { "INHIBIT_COMMON_ALLOCATION", INHIBIT_COMMON_ALLOCATION },
 { "INPUT", INPUT },
 { "KEEP", KEEP },
 { "LENGTH", LENGTH },
 { "LOADADDR", LOADADDR },
 { "LONG", LONG },
 { "MAP", MAP },
 { "MAX", MAX_K },
 { "MEMORY", MEMORY },
 { "MIN", MIN_K },
 { "NEXT", NEXT },
 { "NOCROSSREFS", NOCROSSREFS },
 { "NOFLOAT", NOFLOAT },
 { "NOLOAD", NOLOAD },
 { "ONLY_IF_RO", ONLY_IF_RO },
 { "ONLY_IF_RW", ONLY_IF_RW },
 { "OPTION", OPTION },
 { "ORIGIN", ORIGIN },
 { "OUTPUT", OUTPUT },
 { "OUTPUT_ARCH", OUTPUT_ARCH },
 { "OUTPUT_FORMAT", OUTPUT_FORMAT },
 { "OVERLAY", OVERLAY },
 { "PHDRS", PHDRS },
 { "PROVIDE", PROVIDE },
 { "PROVIDE_HIDDEN", PROVIDE_HIDDEN },
 { "QUAD", QUAD },
 { "SEARCH_DIR", SEARCH_DIR },
 { "SECTIONS", SECTIONS },
 { "SEGMENT_START", SEGMENT_START },
 { "SHORT", SHORT },
 { "SIZEOF", SIZEOF },
 { "SIZEOF_HEADERS", SIZEOF_HEADERS },
 { "SORT", SORT_BY_NAME },
 { "SORT_BY_ALIGNMENT", SORT_BY_ALIGNMENT },
 { "SORT_BY_INIT_PRIORITY", SORT_BY_INIT_PRIORITY },
 { "SORT_BY_NAME", SORT_BY_NAME },
 { "SPECIAL", SPECIAL },
 { "SQUAD", SQUAD },
 { "STARTUP", STARTUP },
 { "SUBALIGN", SUBALIGN },
 { "SYSLIB", SYSLIB },
 { "TARGET", TARGET_K },
 { "TRUNCATE", TRUNCATE },
 { "VERSION", VERSIONK },
 { "global", GLOBAL },
 { "l", LENGTH },
 { "len", LENGTH },
 { "local", LOCAL },
 { "o", ORIGIN },
 { "org", ORIGIN },
 { "sizeof_headers", SIZEOF_HEADERS },
};

static const Keyword_to_parsecode
script_keywords(&script_keyword_parsecodes[0],
               (sizeof(script_keyword_parsecodes)
                / sizeof(script_keyword_parsecodes[0])));

static const Keyword_to_parsecode::Keyword_parsecode
version_script_keyword_parsecodes[] =
{
 { "extern", EXTERN },
 { "global", GLOBAL },
 { "local", LOCAL },
};

static const Keyword_to_parsecode
version_script_keywords(&version_script_keyword_parsecodes[0],
                       (sizeof(version_script_keyword_parsecodes)
                        / sizeof(version_script_keyword_parsecodes[0])));

static const Keyword_to_parsecode::Keyword_parsecode
dynamic_list_keyword_parsecodes[] =
{
 { "extern", EXTERN },
};

static const Keyword_to_parsecode
dynamic_list_keywords(&dynamic_list_keyword_parsecodes[0],
                     (sizeof(dynamic_list_keyword_parsecodes)
                      / sizeof(dynamic_list_keyword_parsecodes[0])));



// Comparison function passed to bsearch.

extern "C"
{

struct Ktt_key
{
 const char* str;
 size_t len;
};

static int
ktt_compare(const void* keyv, const void* kttv)
{
 const Ktt_key* key = static_cast<const Ktt_key*>(keyv);
 const Keyword_to_parsecode::Keyword_parsecode* ktt =
   static_cast<const Keyword_to_parsecode::Keyword_parsecode*>(kttv);
 int i = strncmp(key->str, ktt->keyword, key->len);
 if (i != 0)
   return i;
 if (ktt->keyword[key->len] != '\0')
   return -1;
 return 0;
}

} // End extern "C".

int
Keyword_to_parsecode::keyword_to_parsecode(const char* keyword,
                                          size_t len) const
{
 Ktt_key key;
 key.str = keyword;
 key.len = len;
 void* kttv = bsearch(&key,
                      this->keyword_parsecodes_,
                      this->keyword_count_,
                      sizeof(this->keyword_parsecodes_[0]),
                      ktt_compare);
 if (kttv == NULL)
   return 0;
 Keyword_parsecode* ktt = static_cast<Keyword_parsecode*>(kttv);
 return ktt->parsecode;
}

// The following structs are used within the VersionInfo class as well
// as in the bison helper functions.  They store the information
// parsed from the version script.

// A single version expression.
// For example, pattern="std::map*" and language="C++".
struct Version_expression
{
 Version_expression(const std::string& a_pattern,
                    Version_script_info::Language a_language,
                    bool a_exact_match)
   : pattern(a_pattern), language(a_language), exact_match(a_exact_match),
     was_matched_by_symbol(false)
 { }

 std::string pattern;
 Version_script_info::Language language;
 // If false, we use glob() to match pattern.  If true, we use strcmp().
 bool exact_match;
 // True if --no-undefined-version is in effect and we found this
 // version in get_symbol_version.  We use mutable because this
 // struct is generally not modifiable after it has been created.
 mutable bool was_matched_by_symbol;
};

// A list of expressions.
struct Version_expression_list
{
 std::vector<struct Version_expression> expressions;
};

// A list of which versions upon which another version depends.
// Strings should be from the Stringpool.
struct Version_dependency_list
{
 std::vector<std::string> dependencies;
};

// The total definition of a version.  It includes the tag for the
// version, its global and local expressions, and any dependencies.
struct Version_tree
{
 Version_tree()
     : tag(), global(NULL), local(NULL), dependencies(NULL)
 { }

 std::string tag;
 const struct Version_expression_list* global;
 const struct Version_expression_list* local;
 const struct Version_dependency_list* dependencies;
};

// Helper class that calls cplus_demangle when needed and takes care of freeing
// the result.

class Lazy_demangler
{
public:
 Lazy_demangler(const char* symbol, int options)
   : symbol_(symbol), options_(options), demangled_(NULL), did_demangle_(false)
 { }

 ~Lazy_demangler()
 { free(this->demangled_); }

 // Return the demangled name. The actual demangling happens on the first call,
 // and the result is later cached.
 inline char*
 get();

private:
 // The symbol to demangle.
 const char* symbol_;
 // Option flags to pass to cplus_demagle.
 const int options_;
 // The cached demangled value, or NULL if demangling didn't happen yet or
 // failed.
 char* demangled_;
 // Whether we already called cplus_demangle
 bool did_demangle_;
};

// Return the demangled name. The actual demangling happens on the first call,
// and the result is later cached. Returns NULL if the symbol cannot be
// demangled.

inline char*
Lazy_demangler::get()
{
 if (!this->did_demangle_)
   {
     this->demangled_ = cplus_demangle(this->symbol_, this->options_);
     this->did_demangle_ = true;
   }
 return this->demangled_;
}

// Class Version_script_info.

Version_script_info::Version_script_info()
 : dependency_lists_(), expression_lists_(), version_trees_(), globs_(),
   default_version_(NULL), default_is_global_(false), is_finalized_(false)
{
 for (int i = 0; i < LANGUAGE_COUNT; ++i)
   this->exact_[i] = NULL;
}

Version_script_info::~Version_script_info()
{
}

// Forget all the known version script information.

void
Version_script_info::clear()
{
 for (size_t k = 0; k < this->dependency_lists_.size(); ++k)
   delete this->dependency_lists_[k];
 this->dependency_lists_.clear();
 for (size_t k = 0; k < this->version_trees_.size(); ++k)
   delete this->version_trees_[k];
 this->version_trees_.clear();
 for (size_t k = 0; k < this->expression_lists_.size(); ++k)
   delete this->expression_lists_[k];
 this->expression_lists_.clear();
}

// Finalize the version script information.

void
Version_script_info::finalize()
{
 if (!this->is_finalized_)
   {
     this->build_lookup_tables();
     this->is_finalized_ = true;
   }
}

// Return all the versions.

std::vector<std::string>
Version_script_info::get_versions() const
{
 std::vector<std::string> ret;
 for (size_t j = 0; j < this->version_trees_.size(); ++j)
   if (!this->version_trees_[j]->tag.empty())
     ret.push_back(this->version_trees_[j]->tag);
 return ret;
}

// Return the dependencies of VERSION.

std::vector<std::string>
Version_script_info::get_dependencies(const char* version) const
{
 std::vector<std::string> ret;
 for (size_t j = 0; j < this->version_trees_.size(); ++j)
   if (this->version_trees_[j]->tag == version)
     {
       const struct Version_dependency_list* deps =
         this->version_trees_[j]->dependencies;
       if (deps != NULL)
         for (size_t k = 0; k < deps->dependencies.size(); ++k)
           ret.push_back(deps->dependencies[k]);
       return ret;
     }
 return ret;
}

// A version script essentially maps a symbol name to a version tag
// and an indication of whether symbol is global or local within that
// version tag.  Each symbol maps to at most one version tag.
// Unfortunately, in practice, version scripts are ambiguous, and list
// symbols multiple times.  Thus, we have to document the matching
// process.

// This is a description of what the GNU linker does as of 2010-01-11.
// It walks through the version tags in the order in which they appear
// in the version script.  For each tag, it first walks through the
// global patterns for that tag, then the local patterns.  When
// looking at a single pattern, it first applies any language specific
// demangling as specified for the pattern, and then matches the
// resulting symbol name to the pattern.  If it finds an exact match
// for a literal pattern (a pattern enclosed in quotes or with no
// wildcard characters), then that is the match that it uses.  If
// finds a match with a wildcard pattern, then it saves it and
// continues searching.  Wildcard patterns that are exactly "*" are
// saved separately.

// If no exact match with a literal pattern is ever found, then if a
// wildcard match with a global pattern was found it is used,
// otherwise if a wildcard match with a local pattern was found it is
// used.

// This is the result:
//   * If there is an exact match, then we use the first tag in the
//     version script where it matches.
//     + If the exact match in that tag is global, it is used.
//     + Otherwise the exact match in that tag is local, and is used.
//   * Otherwise, if there is any match with a global wildcard pattern:
//     + If there is any match with a wildcard pattern which is not
//       "*", then we use the tag in which the *last* such pattern
//       appears.
//     + Otherwise, we matched "*".  If there is no match with a local
//       wildcard pattern which is not "*", then we use the *last*
//       match with a global "*".  Otherwise, continue.
//   * Otherwise, if there is any match with a local wildcard pattern:
//     + If there is any match with a wildcard pattern which is not
//       "*", then we use the tag in which the *last* such pattern
//       appears.
//     + Otherwise, we matched "*", and we use the tag in which the
//       *last* such match occurred.

// There is an additional wrinkle.  When the GNU linker finds a symbol
// with a version defined in an object file due to a .symver
// directive, it looks up that symbol name in that version tag.  If it
// finds it, it matches the symbol name against the patterns for that
// version.  If there is no match with a global pattern, but there is
// a match with a local pattern, then the GNU linker marks the symbol
// as local.

// We want gold to be generally compatible, but we also want gold to
// be fast.  These are the rules that gold implements:
//   * If there is an exact match for the mangled name, we use it.
//     + If there is more than one exact match, we give a warning, and
//       we use the first tag in the script which matches.
//     + If a symbol has an exact match as both global and local for
//       the same version tag, we give an error.
//   * Otherwise, we look for an extern C++ or an extern Java exact
//     match.  If we find an exact match, we use it.
//     + If there is more than one exact match, we give a warning, and
//       we use the first tag in the script which matches.
//     + If a symbol has an exact match as both global and local for
//       the same version tag, we give an error.
//   * Otherwise, we look through the wildcard patterns, ignoring "*"
//     patterns.  We look through the version tags in reverse order.
//     For each version tag, we look through the global patterns and
//     then the local patterns.  We use the first match we find (i.e.,
//     the last matching version tag in the file).
//   * Otherwise, we use the "*" pattern if there is one.  We give an
//     error if there are multiple "*" patterns.

// At least for now, gold does not look up the version tag for a
// symbol version found in an object file to see if it should be
// forced local.  There are other ways to force a symbol to be local,
// and I don't understand why this one is useful.

// Build a set of fast lookup tables for a version script.

void
Version_script_info::build_lookup_tables()
{
 size_t size = this->version_trees_.size();
 for (size_t j = 0; j < size; ++j)
   {
     const Version_tree* v = this->version_trees_[j];
     this->build_expression_list_lookup(v->local, v, false);
     this->build_expression_list_lookup(v->global, v, true);
   }
}

// If a pattern has backlashes but no unquoted wildcard characters,
// then we apply backslash unquoting and look for an exact match.
// Otherwise we treat it as a wildcard pattern.  This function returns
// true for a wildcard pattern.  Otherwise, it does backslash
// unquoting on *PATTERN and returns false.  If this returns true,
// *PATTERN may have been partially unquoted.

bool
Version_script_info::unquote(std::string* pattern) const
{
 bool saw_backslash = false;
 size_t len = pattern->length();
 size_t j = 0;
 for (size_t i = 0; i < len; ++i)
   {
     if (saw_backslash)
       saw_backslash = false;
     else
       {
         switch ((*pattern)[i])
           {
           case '?': case '[': case '*':
             return true;
           case '\\':
             saw_backslash = true;
             continue;
           default:
             break;
           }
       }

     if (i != j)
       (*pattern)[j] = (*pattern)[i];
     ++j;
   }
 return false;
}

// Add an exact match for MATCH to *PE.  The result of the match is
// V/IS_GLOBAL.

void
Version_script_info::add_exact_match(const std::string& match,
                                    const Version_tree* v, bool is_global,
                                    const Version_expression* ve,
                                    Exact* pe)
{
 std::pair<Exact::iterator, bool> ins =
   pe->insert(std::make_pair(match, Version_tree_match(v, is_global, ve)));
 if (ins.second)
   {
     // This is the first time we have seen this match.
     return;
   }

 Version_tree_match& vtm(ins.first->second);
 if (vtm.real->tag != v->tag)
   {
     // This is an ambiguous match.  We still return the
     // first version that we found in the script, but we
     // record the new version to issue a warning if we
     // wind up looking up this symbol.
     if (vtm.ambiguous == NULL)
       vtm.ambiguous = v;
   }
 else if (is_global != vtm.is_global)
   {
     // We have a match for both the global and local entries for a
     // version tag.  That's got to be wrong.
     gold_error(_("'%s' appears as both a global and a local symbol "
                  "for version '%s' in script"),
                match.c_str(), v->tag.c_str());
   }
}

// Build fast lookup information for EXPLIST and store it in LOOKUP.
// All matches go to V, and IS_GLOBAL is true if they are global
// matches.

void
Version_script_info::build_expression_list_lookup(
   const Version_expression_list* explist,
   const Version_tree* v,
   bool is_global)
{
 if (explist == NULL)
   return;
 size_t size = explist->expressions.size();
 for (size_t i = 0; i < size; ++i)
   {
     const Version_expression& exp(explist->expressions[i]);

     if (exp.pattern.length() == 1 && exp.pattern[0] == '*')
       {
         if (this->default_version_ != NULL
             && this->default_version_->tag != v->tag)
           gold_warning(_("wildcard match appears in both version '%s' "
                          "and '%s' in script"),
                        this->default_version_->tag.c_str(), v->tag.c_str());
         else if (this->default_version_ != NULL
                  && this->default_is_global_ != is_global)
           gold_error(_("wildcard match appears as both global and local "
                        "in version '%s' in script"),
                      v->tag.c_str());
         this->default_version_ = v;
         this->default_is_global_ = is_global;
         continue;
       }

     std::string pattern = exp.pattern;
     if (!exp.exact_match)
       {
         if (this->unquote(&pattern))
           {
             this->globs_.push_back(Glob(&exp, v, is_global));
             continue;
           }
       }

     if (this->exact_[exp.language] == NULL)
       this->exact_[exp.language] = new Exact();
     this->add_exact_match(pattern, v, is_global, &exp,
                           this->exact_[exp.language]);
   }
}

// Return the name to match given a name, a language code, and two
// lazy demanglers.

const char*
Version_script_info::get_name_to_match(const char* name,
                                      int language,
                                      Lazy_demangler* cpp_demangler,
                                      Lazy_demangler* java_demangler) const
{
 switch (language)
   {
   case LANGUAGE_C:
     return name;
   case LANGUAGE_CXX:
     return cpp_demangler->get();
   case LANGUAGE_JAVA:
     return java_demangler->get();
   default:
     gold_unreachable();
   }
}

// Look up SYMBOL_NAME in the list of versions.  Return true if the
// symbol is found, false if not.  If the symbol is found, then if
// PVERSION is not NULL, set *PVERSION to the version tag, and if
// P_IS_GLOBAL is not NULL, set *P_IS_GLOBAL according to whether the
// symbol is global or not.

bool
Version_script_info::get_symbol_version(const char* symbol_name,
                                       std::string* pversion,
                                       bool* p_is_global) const
{
 Lazy_demangler cpp_demangled_name(symbol_name, DMGL_ANSI | DMGL_PARAMS);
 Lazy_demangler java_demangled_name(symbol_name,
                                    DMGL_ANSI | DMGL_PARAMS | DMGL_JAVA);

 gold_assert(this->is_finalized_);
 for (int i = 0; i < LANGUAGE_COUNT; ++i)
   {
     Exact* exact = this->exact_[i];
     if (exact == NULL)
       continue;

     const char* name_to_match = this->get_name_to_match(symbol_name, i,
                                                         &cpp_demangled_name,
                                                         &java_demangled_name);
     if (name_to_match == NULL)
       {
         // If the name can not be demangled, the GNU linker goes
         // ahead and tries to match it anyhow.  That does not
         // make sense to me and I have not implemented it.
         continue;
       }

     Exact::const_iterator pe = exact->find(name_to_match);
     if (pe != exact->end())
       {
         const Version_tree_match& vtm(pe->second);
         if (vtm.ambiguous != NULL)
           gold_warning(_("using '%s' as version for '%s' which is also "
                          "named in version '%s' in script"),
                        vtm.real->tag.c_str(), name_to_match,
                        vtm.ambiguous->tag.c_str());

         if (pversion != NULL)
           *pversion = vtm.real->tag;
         if (p_is_global != NULL)
           *p_is_global = vtm.is_global;

         // If we are using --no-undefined-version, and this is a
         // global symbol, we have to record that we have found this
         // symbol, so that we don't warn about it.  We have to do
         // this now, because otherwise we have no way to get from a
         // non-C language back to the demangled name that we
         // matched.
         if (p_is_global != NULL && vtm.is_global)
           vtm.expression->was_matched_by_symbol = true;

         return true;
       }
   }

 // Look through the glob patterns in reverse order.

 for (Globs::const_reverse_iterator p = this->globs_.rbegin();
      p != this->globs_.rend();
      ++p)
   {
     int language = p->expression->language;
     const char* name_to_match = this->get_name_to_match(symbol_name,
                                                         language,
                                                         &cpp_demangled_name,
                                                         &java_demangled_name);
     if (name_to_match == NULL)
       continue;

     if (fnmatch(p->expression->pattern.c_str(), name_to_match,
                 FNM_NOESCAPE) == 0)
       {
         if (pversion != NULL)
           *pversion = p->version->tag;
         if (p_is_global != NULL)
           *p_is_global = p->is_global;
         return true;
       }
   }

 // Finally, there may be a wildcard.
 if (this->default_version_ != NULL)
   {
     if (pversion != NULL)
       *pversion = this->default_version_->tag;
     if (p_is_global != NULL)
       *p_is_global = this->default_is_global_;
     return true;
   }

 return false;
}

// Give an error if any exact symbol names (not wildcards) appear in a
// version script, but there is no such symbol.

void
Version_script_info::check_unmatched_names(const Symbol_table* symtab) const
{
 for (size_t i = 0; i < this->version_trees_.size(); ++i)
   {
     const Version_tree* vt = this->version_trees_[i];
     if (vt->global == NULL)
       continue;
     for (size_t j = 0; j < vt->global->expressions.size(); ++j)
       {
         const Version_expression& expression(vt->global->expressions[j]);

         // Ignore cases where we used the version because we saw a
         // symbol that we looked up.  Note that
         // WAS_MATCHED_BY_SYMBOL will be true even if the symbol was
         // not a definition.  That's OK as in that case we most
         // likely gave an undefined symbol error anyhow.
         if (expression.was_matched_by_symbol)
           continue;

         // Just ignore names which are in languages other than C.
         // We have no way to look them up in the symbol table.
         if (expression.language != LANGUAGE_C)
           continue;

         // Remove backslash quoting, and ignore wildcard patterns.
         std::string pattern = expression.pattern;
         if (!expression.exact_match)
           {
             if (this->unquote(&pattern))
               continue;
           }

         if (symtab->lookup(pattern.c_str(), vt->tag.c_str()) == NULL)
           gold_error(_("version script assignment of %s to symbol %s "
                        "failed: symbol not defined"),
                      vt->tag.c_str(), pattern.c_str());
       }
   }
}

struct Version_dependency_list*
Version_script_info::allocate_dependency_list()
{
 dependency_lists_.push_back(new Version_dependency_list);
 return dependency_lists_.back();
}

struct Version_expression_list*
Version_script_info::allocate_expression_list()
{
 expression_lists_.push_back(new Version_expression_list);
 return expression_lists_.back();
}

struct Version_tree*
Version_script_info::allocate_version_tree()
{
 version_trees_.push_back(new Version_tree);
 return version_trees_.back();
}

// Print for debugging.

void
Version_script_info::print(FILE* f) const
{
 if (this->empty())
   return;

 fprintf(f, "VERSION {");

 for (size_t i = 0; i < this->version_trees_.size(); ++i)
   {
     const Version_tree* vt = this->version_trees_[i];

     if (vt->tag.empty())
       fprintf(f, "  {\n");
     else
       fprintf(f, "  %s {\n", vt->tag.c_str());

     if (vt->global != NULL)
       {
         fprintf(f, "    global :\n");
         this->print_expression_list(f, vt->global);
       }

     if (vt->local != NULL)
       {
         fprintf(f, "    local :\n");
         this->print_expression_list(f, vt->local);
       }

     fprintf(f, "  }");
     if (vt->dependencies != NULL)
       {
         const Version_dependency_list* deps = vt->dependencies;
         for (size_t j = 0; j < deps->dependencies.size(); ++j)
           {
             if (j < deps->dependencies.size() - 1)
               fprintf(f, "\n");
             fprintf(f, "    %s", deps->dependencies[j].c_str());
           }
       }
     fprintf(f, ";\n");
   }

 fprintf(f, "}\n");
}

void
Version_script_info::print_expression_list(
   FILE* f,
   const Version_expression_list* vel) const
{
 Version_script_info::Language current_language = LANGUAGE_C;
 for (size_t i = 0; i < vel->expressions.size(); ++i)
   {
     const Version_expression& ve(vel->expressions[i]);

     if (ve.language != current_language)
       {
         if (current_language != LANGUAGE_C)
           fprintf(f, "      }\n");
         switch (ve.language)
           {
           case LANGUAGE_C:
             break;
           case LANGUAGE_CXX:
             fprintf(f, "      extern \"C++\" {\n");
             break;
           case LANGUAGE_JAVA:
             fprintf(f, "      extern \"Java\" {\n");
             break;
           default:
             gold_unreachable();
           }
         current_language = ve.language;
       }

     fprintf(f, "      ");
     if (current_language != LANGUAGE_C)
       fprintf(f, "  ");

     if (ve.exact_match)
       fprintf(f, "\"");
     fprintf(f, "%s", ve.pattern.c_str());
     if (ve.exact_match)
       fprintf(f, "\"");

     fprintf(f, "\n");
   }

 if (current_language != LANGUAGE_C)
   fprintf(f, "      }\n");
}

} // End namespace gold.

// The remaining functions are extern "C", so it's clearer to not put
// them in namespace gold.

using namespace gold;

// This function is called by the bison parser to return the next
// token.

extern "C" int
yylex(YYSTYPE* lvalp, void* closurev)
{
 Parser_closure* closure = static_cast<Parser_closure*>(closurev);
 const Token* token = closure->next_token();
 switch (token->classification())
   {
   default:
     gold_unreachable();

   case Token::TOKEN_INVALID:
     yyerror(closurev, "invalid character");
     return 0;

   case Token::TOKEN_EOF:
     return 0;

   case Token::TOKEN_STRING:
     {
       // This is either a keyword or a STRING.
       size_t len;
       const char* str = token->string_value(&len);
       int parsecode = 0;
       switch (closure->lex_mode())
         {
         case Lex::LINKER_SCRIPT:
           parsecode = script_keywords.keyword_to_parsecode(str, len);
           break;
         case Lex::VERSION_SCRIPT:
           parsecode = version_script_keywords.keyword_to_parsecode(str, len);
           break;
         case Lex::DYNAMIC_LIST:
           parsecode = dynamic_list_keywords.keyword_to_parsecode(str, len);
           break;
         default:
           break;
         }
       if (parsecode != 0)
         return parsecode;
       lvalp->string.value = str;
       lvalp->string.length = len;
       return STRING;
     }

   case Token::TOKEN_QUOTED_STRING:
     lvalp->string.value = token->string_value(&lvalp->string.length);
     return QUOTED_STRING;

   case Token::TOKEN_OPERATOR:
     return token->operator_value();

   case Token::TOKEN_INTEGER:
     lvalp->integer = token->integer_value();
     return INTEGER;
   }
}

// This function is called by the bison parser to report an error.

extern "C" void
yyerror(void* closurev, const char* message)
{
 Parser_closure* closure = static_cast<Parser_closure*>(closurev);
 gold_error(_("%s:%d:%d: %s"), closure->filename(), closure->lineno(),
            closure->charpos(), message);
}

// Called by the bison parser to add an external symbol to the link.

extern "C" void
script_add_extern(void* closurev, const char* name, size_t length)
{
 Parser_closure* closure = static_cast<Parser_closure*>(closurev);
 closure->script_options()->add_symbol_reference(name, length);
}

// Called by the bison parser to add a file to the link.

extern "C" void
script_add_file(void* closurev, const char* name, size_t length)
{
 Parser_closure* closure = static_cast<Parser_closure*>(closurev);

 // If this is an absolute path, and we found the script in the
 // sysroot, then we want to prepend the sysroot to the file name.
 // For example, this is how we handle a cross link to the x86_64
 // libc.so, which refers to /lib/libc.so.6.
 std::string name_string(name, length);
 const char* extra_search_path = ".";
 std::string script_directory;
 if (IS_ABSOLUTE_PATH(name_string.c_str()))
   {
     if (closure->is_in_sysroot())
       {
         const std::string& sysroot(parameters->options().sysroot());
         gold_assert(!sysroot.empty());
         name_string = sysroot + name_string;
       }
   }
 else
   {
     // In addition to checking the normal library search path, we
     // also want to check in the script-directory.
     const char* slash = strrchr(closure->filename(), '/');
     if (slash != NULL)
       {
         script_directory.assign(closure->filename(),
                                 slash - closure->filename() + 1);
         extra_search_path = script_directory.c_str();
       }
   }

 Input_file_argument file(name_string.c_str(),
                          Input_file_argument::INPUT_FILE_TYPE_FILE,
                          extra_search_path, false,
                          closure->position_dependent_options());
 Input_argument& arg = closure->inputs()->add_file(file);
 arg.set_script_info(closure->script_info());
}

// Called by the bison parser to add a library to the link.

extern "C" void
script_add_library(void* closurev, const char* name, size_t length)
{
 Parser_closure* closure = static_cast<Parser_closure*>(closurev);
 std::string name_string(name, length);

 if (name_string[0] != 'l')
   gold_error(_("library name must be prefixed with -l"));

 Input_file_argument file(name_string.c_str() + 1,
                          Input_file_argument::INPUT_FILE_TYPE_LIBRARY,
                          "", false,
                          closure->position_dependent_options());
 Input_argument& arg = closure->inputs()->add_file(file);
 arg.set_script_info(closure->script_info());
}

// Called by the bison parser to start a group.  If we are already in
// a group, that means that this script was invoked within a
// --start-group --end-group sequence on the command line, or that
// this script was found in a GROUP of another script.  In that case,
// we simply continue the existing group, rather than starting a new
// one.  It is possible to construct a case in which this will do
// something other than what would happen if we did a recursive group,
// but it's hard to imagine why the different behaviour would be
// useful for a real program.  Avoiding recursive groups is simpler
// and more efficient.

extern "C" void
script_start_group(void* closurev)
{
 Parser_closure* closure = static_cast<Parser_closure*>(closurev);
 if (!closure->in_group())
   closure->inputs()->start_group();
}

// Called by the bison parser at the end of a group.

extern "C" void
script_end_group(void* closurev)
{
 Parser_closure* closure = static_cast<Parser_closure*>(closurev);
 if (!closure->in_group())
   closure->inputs()->end_group();
}

// Called by the bison parser to start an AS_NEEDED list.

extern "C" void
script_start_as_needed(void* closurev)
{
 Parser_closure* closure = static_cast<Parser_closure*>(closurev);
 closure->position_dependent_options().set_as_needed(true);
}

// Called by the bison parser at the end of an AS_NEEDED list.

extern "C" void
script_end_as_needed(void* closurev)
{
 Parser_closure* closure = static_cast<Parser_closure*>(closurev);
 closure->position_dependent_options().set_as_needed(false);
}

// Called by the bison parser to set the entry symbol.

extern "C" void
script_set_entry(void* closurev, const char* entry, size_t length)
{
 // We'll parse this exactly the same as --entry=ENTRY on the commandline
 // TODO(csilvers): FIXME -- call set_entry directly.
 std::string arg("--entry=");
 arg.append(entry, length);
 script_parse_option(closurev, arg.c_str(), arg.size());
}

// Called by the bison parser to set whether to define common symbols.

extern "C" void
script_set_common_allocation(void* closurev, int set)
{
 const char* arg = set != 0 ? "--define-common" : "--no-define-common";
 script_parse_option(closurev, arg, strlen(arg));
}

// Called by the bison parser to refer to a symbol.

extern "C" Expression*
script_symbol(void* closurev, const char* name, size_t length)
{
 Parser_closure* closure = static_cast<Parser_closure*>(closurev);
 if (length != 1 || name[0] != '.')
   closure->script_options()->add_symbol_reference(name, length);
 return script_exp_string(name, length);
}

// Called by the bison parser to define a symbol.

extern "C" void
script_set_symbol(void* closurev, const char* name, size_t length,
                 Expression* value, int providei, int hiddeni)
{
 Parser_closure* closure = static_cast<Parser_closure*>(closurev);
 const bool provide = providei != 0;
 const bool hidden = hiddeni != 0;
 closure->script_options()->add_symbol_assignment(name, length,
                                                  closure->parsing_defsym(),
                                                  value, provide, hidden);
 closure->clear_skip_on_incompatible_target();
}

// Called by the bison parser to add an assertion.

extern "C" void
script_add_assertion(void* closurev, Expression* check, const char* message,
                    size_t messagelen)
{
 Parser_closure* closure = static_cast<Parser_closure*>(closurev);
 closure->script_options()->add_assertion(check, message, messagelen);
 closure->clear_skip_on_incompatible_target();
}

// Called by the bison parser to parse an OPTION.

extern "C" void
script_parse_option(void* closurev, const char* option, size_t length)
{
 Parser_closure* closure = static_cast<Parser_closure*>(closurev);
 // We treat the option as a single command-line option, even if
 // it has internal whitespace.
 if (closure->command_line() == NULL)
   {
     // There are some options that we could handle here--e.g.,
     // -lLIBRARY.  Should we bother?
     gold_warning(_("%s:%d:%d: ignoring command OPTION; OPTION is only valid"
                    " for scripts specified via -T/--script"),
                  closure->filename(), closure->lineno(), closure->charpos());
   }
 else
   {
     bool past_a_double_dash_option = false;
     const char* mutable_option = strndup(option, length);
     gold_assert(mutable_option != NULL);
     closure->command_line()->process_one_option(1, &mutable_option, 0,
                                                 &past_a_double_dash_option);
     // The General_options class will quite possibly store a pointer
     // into mutable_option, so we can't free it.  In cases the class
     // does not store such a pointer, this is a memory leak.  Alas. :(
   }
 closure->clear_skip_on_incompatible_target();
}

// Called by the bison parser to handle OUTPUT_FORMAT.  OUTPUT_FORMAT
// takes either one or three arguments.  In the three argument case,
// the format depends on the endianness option, which we don't
// currently support (FIXME).  If we see an OUTPUT_FORMAT for the
// wrong format, then we want to search for a new file.  Returning 0
// here will cause the parser to immediately abort.

extern "C" int
script_check_output_format(void* closurev,
                          const char* default_name, size_t default_length,
                          const char*, size_t, const char*, size_t)
{
 Parser_closure* closure = static_cast<Parser_closure*>(closurev);
 std::string name(default_name, default_length);
 Target* target = select_target_by_bfd_name(name.c_str());
 if (target == NULL || !parameters->is_compatible_target(target))
   {
     if (closure->skip_on_incompatible_target())
       {
         closure->set_found_incompatible_target();
         return 0;
       }
     // FIXME: Should we warn about the unknown target?
   }
 return 1;
}

// Called by the bison parser to handle TARGET.

extern "C" void
script_set_target(void* closurev, const char* target, size_t len)
{
 Parser_closure* closure = static_cast<Parser_closure*>(closurev);
 std::string s(target, len);
 General_options::Object_format format_enum;
 format_enum = General_options::string_to_object_format(s.c_str());
 closure->position_dependent_options().set_format_enum(format_enum);
}

// Called by the bison parser to handle SEARCH_DIR.  This is handled
// exactly like a -L option.

extern "C" void
script_add_search_dir(void* closurev, const char* option, size_t length)
{
 Parser_closure* closure = static_cast<Parser_closure*>(closurev);
 if (closure->command_line() == NULL)
   gold_warning(_("%s:%d:%d: ignoring SEARCH_DIR; SEARCH_DIR is only valid"
                  " for scripts specified via -T/--script"),
                closure->filename(), closure->lineno(), closure->charpos());
 else if (!closure->command_line()->options().nostdlib())
   {
     std::string s = "-L" + std::string(option, length);
     script_parse_option(closurev, s.c_str(), s.size());
   }
}

/* Called by the bison parser to push the lexer into expression
  mode.  */

extern "C" void
script_push_lex_into_expression_mode(void* closurev)
{
 Parser_closure* closure = static_cast<Parser_closure*>(closurev);
 closure->push_lex_mode(Lex::EXPRESSION);
}

/* Called by the bison parser to push the lexer into version
  mode.  */

extern "C" void
script_push_lex_into_version_mode(void* closurev)
{
 Parser_closure* closure = static_cast<Parser_closure*>(closurev);
 if (closure->version_script()->is_finalized())
   gold_error(_("%s:%d:%d: invalid use of VERSION in input file"),
              closure->filename(), closure->lineno(), closure->charpos());
 closure->push_lex_mode(Lex::VERSION_SCRIPT);
}

/* Called by the bison parser to pop the lexer mode.  */

extern "C" void
script_pop_lex_mode(void* closurev)
{
 Parser_closure* closure = static_cast<Parser_closure*>(closurev);
 closure->pop_lex_mode();
}

// Register an entire version node. For example:
//
// GLIBC_2.1 {
//   global: foo;
// } GLIBC_2.0;
//
// - tag is "GLIBC_2.1"
// - tree contains the information "global: foo"
// - deps contains "GLIBC_2.0"

extern "C" void
script_register_vers_node(void*,
                         const char* tag,
                         int taglen,
                         struct Version_tree* tree,
                         struct Version_dependency_list* deps)
{
 gold_assert(tree != NULL);
 tree->dependencies = deps;
 if (tag != NULL)
   tree->tag = std::string(tag, taglen);
}

// Add a dependencies to the list of existing dependencies, if any,
// and return the expanded list.

extern "C" struct Version_dependency_list*
script_add_vers_depend(void* closurev,
                      struct Version_dependency_list* all_deps,
                      const char* depend_to_add, int deplen)
{
 Parser_closure* closure = static_cast<Parser_closure*>(closurev);
 if (all_deps == NULL)
   all_deps = closure->version_script()->allocate_dependency_list();
 all_deps->dependencies.push_back(std::string(depend_to_add, deplen));
 return all_deps;
}

// Add a pattern expression to an existing list of expressions, if any.

extern "C" struct Version_expression_list*
script_new_vers_pattern(void* closurev,
                       struct Version_expression_list* expressions,
                       const char* pattern, int patlen, int exact_match)
{
 Parser_closure* closure = static_cast<Parser_closure*>(closurev);
 if (expressions == NULL)
   expressions = closure->version_script()->allocate_expression_list();
 expressions->expressions.push_back(
     Version_expression(std::string(pattern, patlen),
                        closure->get_current_language(),
                        static_cast<bool>(exact_match)));
 return expressions;
}

// Attaches b to the end of a, and clears b.  So a = a + b and b = {}.

extern "C" struct Version_expression_list*
script_merge_expressions(struct Version_expression_list* a,
                        struct Version_expression_list* b)
{
 a->expressions.insert(a->expressions.end(),
                       b->expressions.begin(), b->expressions.end());
 // We could delete b and remove it from expressions_lists_, but
 // that's a lot of work.  This works just as well.
 b->expressions.clear();
 return a;
}

// Combine the global and local expressions into a a Version_tree.

extern "C" struct Version_tree*
script_new_vers_node(void* closurev,
                    struct Version_expression_list* global,
                    struct Version_expression_list* local)
{
 Parser_closure* closure = static_cast<Parser_closure*>(closurev);
 Version_tree* tree = closure->version_script()->allocate_version_tree();
 tree->global = global;
 tree->local = local;
 return tree;
}

// Handle a transition in language, such as at the
// start or end of 'extern "C++"'

extern "C" void
version_script_push_lang(void* closurev, const char* lang, int langlen)
{
 Parser_closure* closure = static_cast<Parser_closure*>(closurev);
 std::string language(lang, langlen);
 Version_script_info::Language code;
 if (language.empty() || language == "C")
   code = Version_script_info::LANGUAGE_C;
 else if (language == "C++")
   code = Version_script_info::LANGUAGE_CXX;
 else if (language == "Java")
   code = Version_script_info::LANGUAGE_JAVA;
 else
   {
     char* buf = new char[langlen + 100];
     snprintf(buf, langlen + 100,
              _("unrecognized version script language '%s'"),
              language.c_str());
     yyerror(closurev, buf);
     delete[] buf;
     code = Version_script_info::LANGUAGE_C;
   }
 closure->push_language(code);
}

extern "C" void
version_script_pop_lang(void* closurev)
{
 Parser_closure* closure = static_cast<Parser_closure*>(closurev);
 closure->pop_language();
}

// Called by the bison parser to start a SECTIONS clause.

extern "C" void
script_start_sections(void* closurev)
{
 Parser_closure* closure = static_cast<Parser_closure*>(closurev);
 closure->script_options()->script_sections()->start_sections();
 closure->clear_skip_on_incompatible_target();
}

// Called by the bison parser to finish a SECTIONS clause.

extern "C" void
script_finish_sections(void* closurev)
{
 Parser_closure* closure = static_cast<Parser_closure*>(closurev);
 closure->script_options()->script_sections()->finish_sections();
}

// Start processing entries for an output section.

extern "C" void
script_start_output_section(void* closurev, const char* name, size_t namelen,
                           const struct Parser_output_section_header* header)
{
 Parser_closure* closure = static_cast<Parser_closure*>(closurev);
 closure->script_options()->script_sections()->start_output_section(name,
                                                                    namelen,
                                                                    header);
}

// Finish processing entries for an output section.

extern "C" void
script_finish_output_section(void* closurev,
                            const struct Parser_output_section_trailer* trail)
{
 Parser_closure* closure = static_cast<Parser_closure*>(closurev);
 closure->script_options()->script_sections()->finish_output_section(trail);
}

// Add a data item (e.g., "WORD (0)") to the current output section.

extern "C" void
script_add_data(void* closurev, int data_token, Expression* val)
{
 Parser_closure* closure = static_cast<Parser_closure*>(closurev);
 int size;
 bool is_signed = true;
 switch (data_token)
   {
   case QUAD:
     size = 8;
     is_signed = false;
     break;
   case SQUAD:
     size = 8;
     break;
   case LONG:
     size = 4;
     break;
   case SHORT:
     size = 2;
     break;
   case BYTE:
     size = 1;
     break;
   default:
     gold_unreachable();
   }
 closure->script_options()->script_sections()->add_data(size, is_signed, val);
}

// Add a clause setting the fill value to the current output section.

extern "C" void
script_add_fill(void* closurev, Expression* val)
{
 Parser_closure* closure = static_cast<Parser_closure*>(closurev);
 closure->script_options()->script_sections()->add_fill(val);
}

// Add a new input section specification to the current output
// section.

extern "C" void
script_add_input_section(void* closurev,
                        const struct Input_section_spec* spec,
                        int keepi)
{
 Parser_closure* closure = static_cast<Parser_closure*>(closurev);
 bool keep = keepi != 0;
 closure->script_options()->script_sections()->add_input_section(spec, keep);
}

// When we see DATA_SEGMENT_ALIGN we record that following output
// sections may be relro.

extern "C" void
script_data_segment_align(void* closurev)
{
 Parser_closure* closure = static_cast<Parser_closure*>(closurev);
 if (!closure->script_options()->saw_sections_clause())
   gold_error(_("%s:%d:%d: DATA_SEGMENT_ALIGN not in SECTIONS clause"),
              closure->filename(), closure->lineno(), closure->charpos());
 else
   closure->script_options()->script_sections()->data_segment_align();
}

// When we see DATA_SEGMENT_RELRO_END we know that all output sections
// since DATA_SEGMENT_ALIGN should be relro.

extern "C" void
script_data_segment_relro_end(void* closurev)
{
 Parser_closure* closure = static_cast<Parser_closure*>(closurev);
 if (!closure->script_options()->saw_sections_clause())
   gold_error(_("%s:%d:%d: DATA_SEGMENT_ALIGN not in SECTIONS clause"),
              closure->filename(), closure->lineno(), closure->charpos());
 else
   closure->script_options()->script_sections()->data_segment_relro_end();
}

// Create a new list of string/sort pairs.

extern "C" String_sort_list_ptr
script_new_string_sort_list(const struct Wildcard_section* string_sort)
{
 return new String_sort_list(1, *string_sort);
}

// Add an entry to a list of string/sort pairs.  The way the parser
// works permits us to simply modify the first parameter, rather than
// copy the vector.

extern "C" String_sort_list_ptr
script_string_sort_list_add(String_sort_list_ptr pv,
                           const struct Wildcard_section* string_sort)
{
 if (pv == NULL)
   return script_new_string_sort_list(string_sort);
 else
   {
     pv->push_back(*string_sort);
     return pv;
   }
}

// Create a new list of strings.

extern "C" String_list_ptr
script_new_string_list(const char* str, size_t len)
{
 return new String_list(1, std::string(str, len));
}

// Add an element to a list of strings.  The way the parser works
// permits us to simply modify the first parameter, rather than copy
// the vector.

extern "C" String_list_ptr
script_string_list_push_back(String_list_ptr pv, const char* str, size_t len)
{
 if (pv == NULL)
   return script_new_string_list(str, len);
 else
   {
     pv->push_back(std::string(str, len));
     return pv;
   }
}

// Concatenate two string lists.  Either or both may be NULL.  The way
// the parser works permits us to modify the parameters, rather than
// copy the vector.

extern "C" String_list_ptr
script_string_list_append(String_list_ptr pv1, String_list_ptr pv2)
{
 if (pv1 == NULL)
   return pv2;
 if (pv2 == NULL)
   return pv1;
 pv1->insert(pv1->end(), pv2->begin(), pv2->end());
 return pv1;
}

// Add a new program header.

extern "C" void
script_add_phdr(void* closurev, const char* name, size_t namelen,
               unsigned int type, const Phdr_info* info)
{
 Parser_closure* closure = static_cast<Parser_closure*>(closurev);
 bool includes_filehdr = info->includes_filehdr != 0;
 bool includes_phdrs = info->includes_phdrs != 0;
 bool is_flags_valid = info->is_flags_valid != 0;
 Script_sections* ss = closure->script_options()->script_sections();
 ss->add_phdr(name, namelen, type, includes_filehdr, includes_phdrs,
              is_flags_valid, info->flags, info->load_address);
 closure->clear_skip_on_incompatible_target();
}

// Convert a program header string to a type.

#define PHDR_TYPE(NAME) { #NAME, sizeof(#NAME) - 1, elfcpp::NAME }

static struct
{
 const char* name;
 size_t namelen;
 unsigned int val;
} phdr_type_names[] =
{
 PHDR_TYPE(PT_NULL),
 PHDR_TYPE(PT_LOAD),
 PHDR_TYPE(PT_DYNAMIC),
 PHDR_TYPE(PT_INTERP),
 PHDR_TYPE(PT_NOTE),
 PHDR_TYPE(PT_SHLIB),
 PHDR_TYPE(PT_PHDR),
 PHDR_TYPE(PT_TLS),
 PHDR_TYPE(PT_GNU_EH_FRAME),
 PHDR_TYPE(PT_GNU_STACK),
 PHDR_TYPE(PT_GNU_RELRO)
};

extern "C" unsigned int
script_phdr_string_to_type(void* closurev, const char* name, size_t namelen)
{
 for (unsigned int i = 0;
      i < sizeof(phdr_type_names) / sizeof(phdr_type_names[0]);
      ++i)
   if (namelen == phdr_type_names[i].namelen
       && strncmp(name, phdr_type_names[i].name, namelen) == 0)
     return phdr_type_names[i].val;
 yyerror(closurev, _("unknown PHDR type (try integer)"));
 return elfcpp::PT_NULL;
}

extern "C" void
script_saw_segment_start_expression(void* closurev)
{
 Parser_closure* closure = static_cast<Parser_closure*>(closurev);
 Script_sections* ss = closure->script_options()->script_sections();
 ss->set_saw_segment_start_expression(true);
}

extern "C" void
script_set_section_region(void* closurev, const char* name, size_t namelen,
                         int set_vma)
{
 Parser_closure* closure = static_cast<Parser_closure*>(closurev);
 if (!closure->script_options()->saw_sections_clause())
   {
     gold_error(_("%s:%d:%d: MEMORY region '%.*s' referred to outside of "
                  "SECTIONS clause"),
                closure->filename(), closure->lineno(), closure->charpos(),
                static_cast<int>(namelen), name);
     return;
   }

 Script_sections* ss = closure->script_options()->script_sections();
 Memory_region* mr = ss->find_memory_region(name, namelen);
 if (mr == NULL)
   {
     gold_error(_("%s:%d:%d: MEMORY region '%.*s' not declared"),
                closure->filename(), closure->lineno(), closure->charpos(),
                static_cast<int>(namelen), name);
     return;
   }

 ss->set_memory_region(mr, set_vma);
}

extern "C" void
script_add_memory(void* closurev, const char* name, size_t namelen,
                 unsigned int attrs, Expression* origin, Expression* length)
{
 Parser_closure* closure = static_cast<Parser_closure*>(closurev);
 Script_sections* ss = closure->script_options()->script_sections();
 ss->add_memory_region(name, namelen, attrs, origin, length);
}

extern "C" unsigned int
script_parse_memory_attr(void* closurev, const char* attrs, size_t attrlen,
                        int invert)
{
 int attributes = 0;

 while (attrlen--)
   switch (*attrs++)
     {
     case 'R':
     case 'r':
       attributes |= MEM_READABLE; break;
     case 'W':
     case 'w':
       attributes |= MEM_READABLE | MEM_WRITEABLE; break;
     case 'X':
     case 'x':
       attributes |= MEM_EXECUTABLE; break;
     case 'A':
     case 'a':
       attributes |= MEM_ALLOCATABLE; break;
     case 'I':
     case 'i':
     case 'L':
     case 'l':
       attributes |= MEM_INITIALIZED; break;
     default:
       yyerror(closurev, _("unknown MEMORY attribute"));
     }

 if (invert)
   attributes = (~ attributes) & MEM_ATTR_MASK;

 return attributes;
}

extern "C" void
script_include_directive(int first_token, void* closurev,
                        const char* filename, size_t length)
{
 Parser_closure* closure = static_cast<Parser_closure*>(closurev);
 std::string name(filename, length);
 Command_line* cmdline = closure->command_line();
 read_script_file(name.c_str(), cmdline, &cmdline->script_options(),
                  first_token, Lex::LINKER_SCRIPT);
}

// Functions for memory regions.

extern "C" Expression*
script_exp_function_origin(void* closurev, const char* name, size_t namelen)
{
 Parser_closure* closure = static_cast<Parser_closure*>(closurev);
 Script_sections* ss = closure->script_options()->script_sections();
 Expression* origin = ss->find_memory_region_origin(name, namelen);

 if (origin == NULL)
   {
     gold_error(_("undefined memory region '%s' referenced "
                  "in ORIGIN expression"),
                name);
     // Create a dummy expression to prevent crashes later on.
     origin = script_exp_integer(0);
   }

 return origin;
}

extern "C" Expression*
script_exp_function_length(void* closurev, const char* name, size_t namelen)
{
 Parser_closure* closure = static_cast<Parser_closure*>(closurev);
 Script_sections* ss = closure->script_options()->script_sections();
 Expression* length = ss->find_memory_region_length(name, namelen);

 if (length == NULL)
   {
     gold_error(_("undefined memory region '%s' referenced "
                  "in LENGTH expression"),
                name);
     // Create a dummy expression to prevent crashes later on.
     length = script_exp_integer(0);
   }

 return length;
}