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// script.cc -- handle linker scripts for gold.
// Copyright (C) 2006-2016 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
// MA 02110-1301, USA.
#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)
{
if (*p == '\0')
{
*pp = p;
return this->make_eof_token(p);
}
// Skip whitespace quickly.
while (*p == ' ' || *p == '\t' || *p == '\r')
++p;
if (*p == '\n')
{
++p;
++this->lineno_;
this->linestart_ = p;
continue;
}
// Skip C style comments.
if (p[0] == '/' && p[1] == '*')
{
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 (*p == '#')
{
*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(p[0], p[1]))
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);
}
// Check for a number.
if (this->can_start_hex(p[0], p[1], p[2]))
return this->gather_token(Token::TOKEN_INTEGER,
&Lex::can_continue_hex,
p, p + 3, pp);
if (Lex::can_start_number(p[0]))
return this->gather_token(Token::TOKEN_INTEGER,
&Lex::can_continue_number,
p, p + 1, pp);
// Check for operators.
int opcode = Lex::three_char_operator(p[0], p[1], p[2]);
if (opcode != 0)
{
*pp = p + 3;
return this->make_token(opcode, p);
}
opcode = Lex::two_char_operator(p[0], p[1]);
if (opcode != 0)
{
*pp = p + 2;
return this->make_token(opcode, p);
}
opcode = Lex::one_char_operator(p[0]);
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;
}
// 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.