/* Disassembly display.
Copyright (C) 1998-2019 Free Software Foundation, Inc.
Contributed by Hewlett-Packard Company.
This file is part of GDB.
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, see . */
#include "defs.h"
#include "arch-utils.h"
#include "symtab.h"
#include "breakpoint.h"
#include "frame.h"
#include "value.h"
#include "source.h"
#include "disasm.h"
#include "tui/tui.h"
#include "tui/tui-command.h"
#include "tui/tui-data.h"
#include "tui/tui-win.h"
#include "tui/tui-layout.h"
#include "tui/tui-winsource.h"
#include "tui/tui-stack.h"
#include "tui/tui-file.h"
#include "tui/tui-disasm.h"
#include "tui/tui-source.h"
#include "progspace.h"
#include "objfiles.h"
#include "cli/cli-style.h"
#include "gdb_curses.h"
struct tui_asm_line
{
CORE_ADDR addr;
std::string addr_string;
size_t addr_size;
std::string insn;
};
/* Helper function to find the number of characters in STR, skipping
any ANSI escape sequences. */
static size_t
len_without_escapes (const std::string &str)
{
size_t len = 0;
const char *ptr = str.c_str ();
char c;
while ((c = *ptr++) != '\0')
{
if (c == '\033')
{
ui_file_style style;
size_t n_read;
if (style.parse (ptr, &n_read))
ptr += n_read;
else
{
/* Shouldn't happen, but just skip the ESC if it somehow
does. */
++ptr;
}
}
else
++len;
}
return len;
}
/* Function to set the disassembly window's content.
Disassemble count lines starting at pc.
Return address of the count'th instruction after pc. */
static CORE_ADDR
tui_disassemble (struct gdbarch *gdbarch,
std::vector &asm_lines,
CORE_ADDR pc, int pos, int count,
size_t *addr_size = nullptr)
{
bool term_out = source_styling && gdb_stdout->can_emit_style_escape ();
string_file gdb_dis_out (term_out);
/* Now construct each line. */
for (int i = 0; i < count; ++i)
{
print_address (gdbarch, pc, &gdb_dis_out);
asm_lines[pos + i].addr = pc;
asm_lines[pos + i].addr_string = std::move (gdb_dis_out.string ());
gdb_dis_out.clear ();
if (addr_size != nullptr)
{
size_t new_size;
if (term_out)
new_size = len_without_escapes (asm_lines[pos + i].addr_string);
else
new_size = asm_lines[pos + i].addr_string.size ();
*addr_size = std::max (*addr_size, new_size);
asm_lines[pos + i].addr_size = new_size;
}
pc = pc + gdb_print_insn (gdbarch, pc, &gdb_dis_out, NULL);
asm_lines[pos + i].insn = std::move (gdb_dis_out.string ());
/* Reset the buffer to empty. */
gdb_dis_out.clear ();
}
return pc;
}
/* Find the disassembly address that corresponds to FROM lines above
or below the PC. Variable sized instructions are taken into
account by the algorithm. */
static CORE_ADDR
tui_find_disassembly_address (struct gdbarch *gdbarch, CORE_ADDR pc, int from)
{
CORE_ADDR new_low;
int max_lines;
max_lines = (from > 0) ? from : - from;
if (max_lines <= 1)
return pc;
std::vector asm_lines (max_lines);
new_low = pc;
if (from > 0)
{
tui_disassemble (gdbarch, asm_lines, pc, 0, max_lines);
new_low = asm_lines[max_lines - 1].addr;
}
else
{
CORE_ADDR last_addr;
int pos;
struct bound_minimal_symbol msymbol;
/* Find backward an address which is a symbol and for which
disassembling from that address will fill completely the
window. */
pos = max_lines - 1;
do {
new_low -= 1 * max_lines;
msymbol = lookup_minimal_symbol_by_pc_section (new_low, 0);
if (msymbol.minsym)
new_low = BMSYMBOL_VALUE_ADDRESS (msymbol);
else
new_low += 1 * max_lines;
tui_disassemble (gdbarch, asm_lines, new_low, 0, max_lines);
last_addr = asm_lines[pos].addr;
} while (last_addr > pc && msymbol.minsym);
/* Scan forward disassembling one instruction at a time until
the last visible instruction of the window matches the pc.
We keep the disassembled instructions in the 'lines' window
and shift it downward (increasing its addresses). */
if (last_addr < pc)
do
{
CORE_ADDR next_addr;
pos++;
if (pos >= max_lines)
pos = 0;
next_addr = tui_disassemble (gdbarch, asm_lines,
last_addr, pos, 1);
/* If there are some problems while disassembling exit. */
if (next_addr <= last_addr)
break;
last_addr = next_addr;
} while (last_addr <= pc);
pos++;
if (pos >= max_lines)
pos = 0;
new_low = asm_lines[pos].addr;
}
return new_low;
}
/* Function to set the disassembly window's content. */
bool
tui_disasm_window::set_contents (struct gdbarch *arch,
const struct symtab_and_line &sal)
{
int i;
int offset = horizontal_offset;
int max_lines, line_width;
CORE_ADDR cur_pc;
struct tui_locator_window *locator = tui_locator_win_info_ptr ();
int tab_len = tui_tab_width;
int insn_pos;
CORE_ADDR pc = sal.pc;
if (pc == 0)
return false;
gdbarch = arch;
start_line_or_addr.loa = LOA_ADDRESS;
start_line_or_addr.u.addr = pc;
cur_pc = locator->addr;
/* Window size, excluding highlight box. */
max_lines = height - 2;
line_width = width - TUI_EXECINFO_SIZE - 2;
/* Get temporary table that will hold all strings (addr & insn). */
std::vector asm_lines (max_lines);
size_t addr_size = 0;
tui_disassemble (gdbarch, asm_lines, pc, 0, max_lines, &addr_size);
/* Align instructions to the same column. */
insn_pos = (1 + (addr_size / tab_len)) * tab_len;
/* Now construct each line. */
content.resize (max_lines);
for (i = 0; i < max_lines; i++)
{
tui_source_element *src = &content[i];
std::string line
= (asm_lines[i].addr_string
+ n_spaces (insn_pos - asm_lines[i].addr_size)
+ asm_lines[i].insn);
const char *ptr = line.c_str ();
src->line = tui_copy_source_line (&ptr, -1, offset, line_width, 0);
src->line_or_addr.loa = LOA_ADDRESS;
src->line_or_addr.u.addr = asm_lines[i].addr;
src->is_exec_point = asm_lines[i].addr == cur_pc;
}
return true;
}
void
tui_get_begin_asm_address (struct gdbarch **gdbarch_p, CORE_ADDR *addr_p)
{
struct tui_locator_window *locator;
struct gdbarch *gdbarch = get_current_arch ();
CORE_ADDR addr = 0;
locator = tui_locator_win_info_ptr ();
if (locator->addr == 0)
{
if (have_full_symbols () || have_partial_symbols ())
{
set_default_source_symtab_and_line ();
struct symtab_and_line sal = get_current_source_symtab_and_line ();
if (sal.symtab != nullptr)
find_line_pc (sal.symtab, sal.line, &addr);
}
if (addr == 0)
{
struct bound_minimal_symbol main_symbol
= lookup_minimal_symbol (main_name (), nullptr, nullptr);
if (main_symbol.minsym != nullptr)
addr = BMSYMBOL_VALUE_ADDRESS (main_symbol);
}
}
else /* The target is executing. */
{
gdbarch = locator->gdbarch;
addr = locator->addr;
}
*gdbarch_p = gdbarch;
*addr_p = addr;
}
/* Determine what the low address will be to display in the TUI's
disassembly window. This may or may not be the same as the low
address input. */
CORE_ADDR
tui_get_low_disassembly_address (struct gdbarch *gdbarch,
CORE_ADDR low, CORE_ADDR pc)
{
int pos;
/* Determine where to start the disassembly so that the pc is about
in the middle of the viewport. */
if (tui_win_list[DISASSEM_WIN] != NULL)
pos = tui_win_list[DISASSEM_WIN]->height;
else if (TUI_CMD_WIN == NULL)
pos = tui_term_height () / 2 - 2;
else
pos = tui_term_height () - TUI_CMD_WIN->height - 2;
pos = (pos - 2) / 2;
pc = tui_find_disassembly_address (gdbarch, pc, -pos);
if (pc < low)
pc = low;
return pc;
}
/* Scroll the disassembly forward or backward vertically. */
void
tui_disasm_window::do_scroll_vertical (int num_to_scroll)
{
if (!content.empty ())
{
CORE_ADDR pc;
pc = start_line_or_addr.u.addr;
if (num_to_scroll >= 0)
num_to_scroll++;
else
--num_to_scroll;
symtab_and_line sal {};
sal.pspace = current_program_space;
sal.pc = tui_find_disassembly_address (gdbarch, pc, num_to_scroll);
update_source_window_as_is (gdbarch, sal);
}
}
bool
tui_disasm_window::location_matches_p (struct bp_location *loc, int line_no)
{
return (content[line_no].line_or_addr.loa == LOA_ADDRESS
&& content[line_no].line_or_addr.u.addr == loc->address);
}
bool
tui_disasm_window::addr_is_displayed (CORE_ADDR addr) const
{
bool is_displayed = false;
int threshold = SCROLL_THRESHOLD;
int i = 0;
while (i < content.size () - threshold && !is_displayed)
{
is_displayed
= (content[i].line_or_addr.loa == LOA_ADDRESS
&& content[i].line_or_addr.u.addr == addr);
i++;
}
return is_displayed;
}
void
tui_disasm_window::maybe_update (struct frame_info *fi, symtab_and_line sal)
{
CORE_ADDR low;
struct gdbarch *frame_arch = get_frame_arch (fi);
if (find_pc_partial_function (sal.pc, NULL, &low, NULL) == 0)
{
/* There is no symbol available for current PC. There is no
safe way how to "disassemble backwards". */
low = sal.pc;
}
else
low = tui_get_low_disassembly_address (frame_arch, low, sal.pc);
struct tui_line_or_address a;
a.loa = LOA_ADDRESS;
a.u.addr = low;
if (!addr_is_displayed (sal.pc))
{
sal.pc = low;
update_source_window (frame_arch, sal);
}
else
{
a.u.addr = sal.pc;
set_is_exec_point_at (a);
}
}