// expression.cc -- expressions in linker scripts for gold
-// Copyright 2006, 2007, 2008 Free Software Foundation, Inc.
+// Copyright (C) 2006-2020 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
const Symbol_table* symtab;
// The layout--we use this to get section information.
const Layout* layout;
+ // Whether to check assertions.
+ bool check_assertions;
// Whether expressions can refer to the dot symbol. The dot symbol
// is only available within a SECTIONS clause.
bool is_dot_available;
Output_section* dot_section;
// Points to where the section of the result should be stored.
Output_section** result_section_pointer;
+ // Pointer to where the alignment of the result should be stored.
+ uint64_t* result_alignment_pointer;
+ // Pointer to where the type of the symbol on the RHS should be stored.
+ elfcpp::STT* type_pointer;
+ // Pointer to where the visibility of the symbol on the RHS should be stored.
+ elfcpp::STV* vis_pointer;
+ // Pointer to where the rest of the symbol's st_other field should be stored.
+ unsigned char* nonvis_pointer;
+ // Whether the value is valid. In Symbol_assignment::set_if_absolute, we
+ // may be trying to evaluate the address of a section whose address is not
+ // yet finalized, and we need to fail the evaluation gracefully.
+ bool *is_valid_pointer;
};
// Evaluate an expression.
uint64_t
-Expression::eval(const Symbol_table* symtab, const Layout* layout)
+Expression::eval(const Symbol_table* symtab, const Layout* layout,
+ bool check_assertions)
{
- Output_section* dummy;
- return this->eval_maybe_dot(symtab, layout, false, 0, NULL, &dummy);
+ return this->eval_maybe_dot(symtab, layout, check_assertions, false, 0,
+ NULL, NULL, NULL, NULL, NULL, NULL, false, NULL);
}
// Evaluate an expression which may refer to the dot symbol.
uint64_t
Expression::eval_with_dot(const Symbol_table* symtab, const Layout* layout,
- uint64_t dot_value, Output_section* dot_section,
- Output_section** result_section_pointer)
+ bool check_assertions, uint64_t dot_value,
+ Output_section* dot_section,
+ Output_section** result_section_pointer,
+ uint64_t* result_alignment_pointer,
+ bool is_section_dot_assignment)
{
- return this->eval_maybe_dot(symtab, layout, true, dot_value, dot_section,
- result_section_pointer);
+ return this->eval_maybe_dot(symtab, layout, check_assertions, true,
+ dot_value, dot_section, result_section_pointer,
+ result_alignment_pointer, NULL, NULL, NULL,
+ is_section_dot_assignment, NULL);
}
// Evaluate an expression which may or may not refer to the dot
uint64_t
Expression::eval_maybe_dot(const Symbol_table* symtab, const Layout* layout,
- bool is_dot_available, uint64_t dot_value,
- Output_section* dot_section,
- Output_section** result_section_pointer)
+ bool check_assertions, bool is_dot_available,
+ uint64_t dot_value, Output_section* dot_section,
+ Output_section** result_section_pointer,
+ uint64_t* result_alignment_pointer,
+ elfcpp::STT* type_pointer,
+ elfcpp::STV* vis_pointer,
+ unsigned char* nonvis_pointer,
+ bool is_section_dot_assignment,
+ bool* is_valid_pointer)
{
Expression_eval_info eei;
eei.symtab = symtab;
eei.layout = layout;
+ eei.check_assertions = check_assertions;
eei.is_dot_available = is_dot_available;
eei.dot_value = dot_value;
eei.dot_section = dot_section;
// We assume the value is absolute, and only set this to a section
- // if we find a section relative reference.
- *result_section_pointer = NULL;
+ // if we find a section-relative reference.
+ if (result_section_pointer != NULL)
+ *result_section_pointer = NULL;
eei.result_section_pointer = result_section_pointer;
- return this->value(&eei);
+ // For symbol=symbol assignments, we need to track the type, visibility,
+ // and remaining st_other bits.
+ eei.type_pointer = type_pointer;
+ eei.vis_pointer = vis_pointer;
+ eei.nonvis_pointer = nonvis_pointer;
+
+ eei.result_alignment_pointer = result_alignment_pointer;
+
+ // Assume the value is valid until we try to evaluate an expression
+ // that can't be evaluated yet.
+ bool is_valid = true;
+ eei.is_valid_pointer = &is_valid;
+
+ uint64_t val = this->value(&eei);
+
+ if (is_valid_pointer != NULL)
+ *is_valid_pointer = is_valid;
+ else
+ gold_assert(is_valid);
+
+ // If this is an assignment to dot within a section, and the value
+ // is absolute, treat it as a section-relative offset.
+ if (is_section_dot_assignment && *result_section_pointer == NULL)
+ {
+ gold_assert(dot_section != NULL);
+ val += dot_section->address();
+ *result_section_pointer = dot_section;
+ }
+ return val;
}
// A number.
uint64_t
value(const Expression_eval_info*);
+ void
+ set_expr_sym_in_real_elf(Symbol_table* symtab) const
+ {
+ Symbol* sym = symtab->lookup(this->name_.c_str());
+ if (sym != NULL)
+ sym->set_in_real_elf();
+ }
+
void
print(FILE* f) const
{ fprintf(f, "%s", this->name_.c_str()); }
return 0;
}
- *eei->result_section_pointer = sym->output_section();
+ if (eei->result_section_pointer != NULL)
+ *eei->result_section_pointer = sym->output_section();
+ if (eei->type_pointer != NULL)
+ *eei->type_pointer = sym->type();
+ if (eei->vis_pointer != NULL)
+ *eei->vis_pointer = sym->visibility();
+ if (eei->nonvis_pointer != NULL)
+ *eei->nonvis_pointer = sym->nonvis();
- if (parameters->get_size() == 32)
+ if (parameters->target().get_size() == 32)
return eei->symtab->get_sized_symbol<32>(sym)->value();
- else if (parameters->get_size() == 64)
+ else if (parameters->target().get_size() == 64)
return eei->symtab->get_sized_symbol<64>(sym)->value();
else
gold_unreachable();
"SECTIONS clause"));
return 0;
}
- *eei->result_section_pointer = eei->dot_section;
+ if (eei->result_section_pointer != NULL)
+ *eei->result_section_pointer = eei->dot_section;
return eei->dot_value;
}
Output_section** arg_section_pointer) const
{
return this->arg_->eval_maybe_dot(eei->symtab, eei->layout,
+ eei->check_assertions,
eei->is_dot_available,
eei->dot_value,
eei->dot_section,
- arg_section_pointer);
+ arg_section_pointer,
+ eei->result_alignment_pointer,
+ NULL,
+ NULL,
+ NULL,
+ false,
+ eei->is_valid_pointer);
}
void
arg_print(FILE* f) const
{ this->arg_->print(f); }
+ void
+ set_expr_sym_in_real_elf(Symbol_table* symtab) const
+ { return this->arg_->set_expr_sym_in_real_elf(symtab); }
+
private:
Expression* arg_;
};
{ \
Output_section* arg_section; \
uint64_t ret = OPERATOR this->arg_value(eei, &arg_section); \
- if (arg_section != NULL && parameters->output_is_object()) \
+ if (arg_section != NULL && parameters->options().relocatable()) \
gold_warning(_("unary " #NAME " applied to section " \
"relative value")); \
return ret; \
protected:
uint64_t
left_value(const Expression_eval_info* eei,
- Output_section** section_pointer) const
+ Output_section** section_pointer,
+ uint64_t* alignment_pointer) const
{
return this->left_->eval_maybe_dot(eei->symtab, eei->layout,
+ eei->check_assertions,
eei->is_dot_available,
eei->dot_value,
eei->dot_section,
- section_pointer);
+ section_pointer,
+ alignment_pointer,
+ NULL,
+ NULL,
+ NULL,
+ false,
+ eei->is_valid_pointer);
}
uint64_t
right_value(const Expression_eval_info* eei,
- Output_section** section_pointer) const
+ Output_section** section_pointer,
+ uint64_t* alignment_pointer) const
{
return this->right_->eval_maybe_dot(eei->symtab, eei->layout,
+ eei->check_assertions,
eei->is_dot_available,
eei->dot_value,
eei->dot_section,
- section_pointer);
+ section_pointer,
+ alignment_pointer,
+ NULL,
+ NULL,
+ NULL,
+ false,
+ eei->is_valid_pointer);
}
void
// This is a call to function FUNCTION_NAME. Print it. This is for
// debugging.
void
- print_function(FILE* f, const char *function_name) const
+ print_function(FILE* f, const char* function_name) const
{
fprintf(f, "%s(", function_name);
this->left_print(f);
fprintf(f, ")");
}
+ void
+ set_expr_sym_in_real_elf(Symbol_table* symtab) const
+ {
+ this->left_->set_expr_sym_in_real_elf(symtab);
+ this->right_->set_expr_sym_in_real_elf(symtab);
+ }
+
private:
Expression* left_;
Expression* right_;
value(const Expression_eval_info* eei) \
{ \
Output_section* left_section; \
- uint64_t left = this->left_value(eei, &left_section); \
+ uint64_t left_alignment = 0; \
+ uint64_t left = this->left_value(eei, &left_section, \
+ &left_alignment); \
Output_section* right_section; \
- uint64_t right = this->right_value(eei, &right_section); \
+ uint64_t right_alignment = 0; \
+ uint64_t right = this->right_value(eei, &right_section, \
+ &right_alignment); \
if (KEEP_RIGHT && left_section == NULL && right_section != NULL) \
- *eei->result_section_pointer = right_section; \
+ { \
+ if (eei->result_section_pointer != NULL) \
+ *eei->result_section_pointer = right_section; \
+ if (eei->result_alignment_pointer != NULL \
+ && right_alignment > *eei->result_alignment_pointer) \
+ *eei->result_alignment_pointer = right_alignment; \
+ } \
else if (KEEP_LEFT \
&& left_section != NULL \
&& right_section == NULL) \
- *eei->result_section_pointer = left_section; \
+ { \
+ if (eei->result_section_pointer != NULL) \
+ *eei->result_section_pointer = left_section; \
+ if (eei->result_alignment_pointer != NULL \
+ && left_alignment > *eei->result_alignment_pointer) \
+ *eei->result_alignment_pointer = left_alignment; \
+ } \
else if ((WARN || left_section != right_section) \
&& (left_section != NULL || right_section != NULL) \
- && parameters->output_is_object()) \
+ && parameters->options().relocatable()) \
gold_warning(_("binary " #NAME " applied to section " \
"relative value")); \
if (IS_DIV && right == 0) \
Output_section** section_pointer) const
{
return this->arg1_->eval_maybe_dot(eei->symtab, eei->layout,
+ eei->check_assertions,
eei->is_dot_available,
eei->dot_value,
eei->dot_section,
- section_pointer);
+ section_pointer,
+ NULL,
+ NULL,
+ NULL,
+ NULL,
+ false,
+ eei->is_valid_pointer);
}
uint64_t
arg2_value(const Expression_eval_info* eei,
- Output_section** section_pointer) const
+ Output_section** section_pointer,
+ uint64_t* alignment_pointer) const
{
- return this->arg1_->eval_maybe_dot(eei->symtab, eei->layout,
+ return this->arg2_->eval_maybe_dot(eei->symtab, eei->layout,
+ eei->check_assertions,
eei->is_dot_available,
eei->dot_value,
eei->dot_section,
- section_pointer);
+ section_pointer,
+ alignment_pointer,
+ NULL,
+ NULL,
+ NULL,
+ false,
+ eei->is_valid_pointer);
}
uint64_t
arg3_value(const Expression_eval_info* eei,
- Output_section** section_pointer) const
+ Output_section** section_pointer,
+ uint64_t* alignment_pointer) const
{
- return this->arg1_->eval_maybe_dot(eei->symtab, eei->layout,
+ return this->arg3_->eval_maybe_dot(eei->symtab, eei->layout,
+ eei->check_assertions,
eei->is_dot_available,
eei->dot_value,
eei->dot_section,
- section_pointer);
+ section_pointer,
+ alignment_pointer,
+ NULL,
+ NULL,
+ NULL,
+ false,
+ eei->is_valid_pointer);
}
void
arg3_print(FILE* f) const
{ this->arg3_->print(f); }
+ void
+ set_expr_sym_in_real_elf(Symbol_table* symtab) const
+ {
+ this->arg1_->set_expr_sym_in_real_elf(symtab);
+ this->arg2_->set_expr_sym_in_real_elf(symtab);
+ this->arg3_->set_expr_sym_in_real_elf(symtab);
+ }
+
private:
Expression* arg1_;
Expression* arg2_;
Output_section* arg1_section;
uint64_t arg1 = this->arg1_value(eei, &arg1_section);
return (arg1
- ? this->arg2_value(eei, eei->result_section_pointer)
- : this->arg3_value(eei, eei->result_section_pointer));
+ ? this->arg2_value(eei, eei->result_section_pointer,
+ eei->result_alignment_pointer)
+ : this->arg3_value(eei, eei->result_section_pointer,
+ eei->result_alignment_pointer));
}
void
value(const Expression_eval_info* eei)
{
Output_section* left_section;
- uint64_t left = this->left_value(eei, &left_section);
+ uint64_t left_alignment;
+ uint64_t left = this->left_value(eei, &left_section, &left_alignment);
Output_section* right_section;
- uint64_t right = this->right_value(eei, &right_section);
+ uint64_t right_alignment;
+ uint64_t right = this->right_value(eei, &right_section, &right_alignment);
if (left_section == right_section)
- *eei->result_section_pointer = left_section;
+ {
+ if (eei->result_section_pointer != NULL)
+ *eei->result_section_pointer = left_section;
+ }
else if ((left_section != NULL || right_section != NULL)
- && parameters->output_is_object())
+ && parameters->options().relocatable())
gold_warning(_("max applied to section relative value"));
+ if (eei->result_alignment_pointer != NULL)
+ {
+ uint64_t ra = *eei->result_alignment_pointer;
+ if (left > right)
+ ra = std::max(ra, left_alignment);
+ else if (right > left)
+ ra = std::max(ra, right_alignment);
+ else
+ ra = std::max(ra, std::max(left_alignment, right_alignment));
+ *eei->result_alignment_pointer = ra;
+ }
return std::max(left, right);
}
value(const Expression_eval_info* eei)
{
Output_section* left_section;
- uint64_t left = this->left_value(eei, &left_section);
+ uint64_t left_alignment;
+ uint64_t left = this->left_value(eei, &left_section, &left_alignment);
Output_section* right_section;
- uint64_t right = this->right_value(eei, &right_section);
+ uint64_t right_alignment;
+ uint64_t right = this->right_value(eei, &right_section, &right_alignment);
if (left_section == right_section)
- *eei->result_section_pointer = left_section;
+ {
+ if (eei->result_section_pointer != NULL)
+ *eei->result_section_pointer = left_section;
+ }
else if ((left_section != NULL || right_section != NULL)
- && parameters->output_is_object())
+ && parameters->options().relocatable())
gold_warning(_("min applied to section relative value"));
+ if (eei->result_alignment_pointer != NULL)
+ {
+ uint64_t ra = *eei->result_alignment_pointer;
+ if (left < right)
+ ra = std::max(ra, left_alignment);
+ else if (right < left)
+ ra = std::max(ra, right_alignment);
+ else
+ ra = std::max(ra, std::max(left_alignment, right_alignment));
+ *eei->result_alignment_pointer = ra;
+ }
return std::min(left, right);
}
value_from_output_section(const Expression_eval_info*,
Output_section*) = 0;
+ // The child class must implement this.
+ virtual uint64_t
+ value_from_script_output_section(uint64_t address, uint64_t load_address,
+ uint64_t addralign, uint64_t size) = 0;
+
// The child class must implement this.
virtual const char*
function_name() const = 0;
{
const char* section_name = this->section_name_.c_str();
Output_section* os = eei->layout->find_output_section(section_name);
- if (os == NULL)
+ if (os != NULL)
+ return this->value_from_output_section(eei, os);
+
+ uint64_t address;
+ uint64_t load_address;
+ uint64_t addralign;
+ uint64_t size;
+ const Script_options* ss = eei->layout->script_options();
+ if (ss->saw_sections_clause())
{
- gold_error("%s called on nonexistent output section '%s'",
- this->function_name(), section_name);
- return 0;
+ if (ss->script_sections()->get_output_section_info(section_name,
+ &address,
+ &load_address,
+ &addralign,
+ &size))
+ return this->value_from_script_output_section(address, load_address,
+ addralign, size);
}
- return this->value_from_output_section(eei, os);
+ gold_error("%s called on nonexistent output section '%s'",
+ this->function_name(), section_name);
+ return 0;
}
// ABSOLUTE function.
uint64_t
value(const Expression_eval_info* eei)
{
- Output_section* dummy;
- uint64_t ret = this->arg_value(eei, &dummy);
+ uint64_t ret = this->arg_value(eei, NULL);
// Force the value to be absolute.
- *eei->result_section_pointer = NULL;
+ if (eei->result_section_pointer != NULL)
+ *eei->result_section_pointer = NULL;
return ret;
}
value(const Expression_eval_info* eei)
{
Output_section* align_section;
- uint64_t align = this->right_value(eei, &align_section);
+ uint64_t align = this->right_value(eei, &align_section, NULL);
if (align_section != NULL
- && parameters->output_is_object())
+ && parameters->options().relocatable())
gold_warning(_("aligning to section relative value"));
- uint64_t value = this->left_value(eei, eei->result_section_pointer);
+ if (eei->result_alignment_pointer != NULL
+ && align > *eei->result_alignment_pointer)
+ {
+ uint64_t a = align;
+ while ((a & (a - 1)) != 0)
+ a &= a - 1;
+ *eei->result_alignment_pointer = a;
+ }
+
+ uint64_t value = this->left_value(eei, eei->result_section_pointer, NULL);
if (align <= 1)
return value;
return ((value + align - 1) / align) * align;
value(const Expression_eval_info* eei)
{
uint64_t value = this->arg_value(eei, eei->result_section_pointer);
- if (!value)
+ if (!value && eei->check_assertions)
gold_error("%s", this->message_.c_str());
return value;
}
value_from_output_section(const Expression_eval_info* eei,
Output_section* os)
{
- *eei->result_section_pointer = os;
- return os->address();
+ if (eei->result_section_pointer != NULL)
+ *eei->result_section_pointer = os;
+ if (os->is_address_valid())
+ return os->address();
+ *eei->is_valid_pointer = false;
+ return 0;
}
+ uint64_t
+ value_from_script_output_section(uint64_t address, uint64_t, uint64_t,
+ uint64_t)
+ { return address; }
+
const char*
function_name() const
{ return "ADDR"; }
Output_section* os)
{ return os->addralign(); }
+ uint64_t
+ value_from_script_output_section(uint64_t, uint64_t, uint64_t addralign,
+ uint64_t)
+ { return addralign; }
+
const char*
function_name() const
{ return "ALIGNOF"; }
switch (this->function_)
{
case CONSTANT_MAXPAGESIZE:
- return parameters->target()->abi_pagesize();
+ return parameters->target().abi_pagesize();
case CONSTANT_COMMONPAGESIZE:
- return parameters->target()->common_pagesize();
+ return parameters->target().common_pagesize();
default:
gold_unreachable();
}
return os->load_address();
else
{
- *eei->result_section_pointer = os;
+ if (eei->result_section_pointer != NULL)
+ *eei->result_section_pointer = os;
return os->address();
}
}
+ uint64_t
+ value_from_script_output_section(uint64_t, uint64_t load_address, uint64_t,
+ uint64_t)
+ { return load_address; }
+
const char*
function_name() const
{ return "LOADADDR"; }
return os->current_data_size();
}
+ uint64_t
+ value_from_script_output_section(uint64_t, uint64_t, uint64_t,
+ uint64_t size)
+ { return size; }
+
const char*
function_name() const
{ return "SIZEOF"; }
{
unsigned int ehdr_size;
unsigned int phdr_size;
- if (parameters->get_size() == 32)
+ if (parameters->target().get_size() == 32)
{
ehdr_size = elfcpp::Elf_sizes<32>::ehdr_size;
phdr_size = elfcpp::Elf_sizes<32>::phdr_size;
}
- else if (parameters->get_size() == 64)
+ else if (parameters->target().get_size() == 64)
{
ehdr_size = elfcpp::Elf_sizes<64>::ehdr_size;
phdr_size = elfcpp::Elf_sizes<64>::phdr_size;
return new Sizeof_headers_expression();
}
-// In the GNU linker SEGMENT_START basically returns the value for
-// -Ttext, -Tdata, or -Tbss. We could implement this by copying the
-// values from General_options to Parameters. But I doubt that
-// anybody actually uses it. The point of it for the GNU linker was
-// because -Ttext set the address of the .text section rather than the
-// text segment. In gold -Ttext sets the text segment address anyhow.
+// SEGMENT_START.
-extern "C" Expression*
-script_exp_function_segment_start(const char*, size_t, Expression*)
+class Segment_start_expression : public Unary_expression
{
- gold_fatal(_("SEGMENT_START not implemented"));
-}
+ public:
+ Segment_start_expression(const char* segment_name, size_t segment_name_len,
+ Expression* default_value)
+ : Unary_expression(default_value),
+ segment_name_(segment_name, segment_name_len)
+ { }
-// Functions for memory regions. These can not be implemented unless
-// and until we implement memory regions.
+ uint64_t
+ value(const Expression_eval_info*);
-extern "C" Expression*
-script_exp_function_origin(const char*, size_t)
+ void
+ print(FILE* f) const
+ {
+ fprintf(f, "SEGMENT_START(\"%s\", ", this->segment_name_.c_str());
+ this->arg_print(f);
+ fprintf(f, ")");
+ }
+
+ private:
+ std::string segment_name_;
+};
+
+uint64_t
+Segment_start_expression::value(const Expression_eval_info* eei)
{
- gold_fatal(_("ORIGIN not implemented"));
+ // Check for command line overrides.
+ if (parameters->options().user_set_Ttext()
+ && this->segment_name_ == ".text")
+ return parameters->options().Ttext();
+ else if (parameters->options().user_set_Tdata()
+ && this->segment_name_ == ".data")
+ return parameters->options().Tdata();
+ else if (parameters->options().user_set_Tbss()
+ && this->segment_name_ == ".bss")
+ return parameters->options().Tbss();
+ else
+ {
+ uint64_t ret = this->arg_value(eei, NULL);
+ // Force the value to be absolute.
+ if (eei->result_section_pointer != NULL)
+ *eei->result_section_pointer = NULL;
+ return ret;
+ }
}
extern "C" Expression*
-script_exp_function_length(const char*, size_t)
+script_exp_function_segment_start(const char* segment_name,
+ size_t segment_name_len,
+ Expression* default_value)
{
- gold_fatal(_("LENGTH not implemented"));
+ return new Segment_start_expression(segment_name, segment_name_len,
+ default_value);
}
} // End namespace gold.