/* Disassembly display.
- Copyright (C) 1998-2019 Free Software Foundation, Inc.
+ Copyright (C) 1998-2020 Free Software Foundation, Inc.
Contributed by Hewlett-Packard Company.
#include "gdb_curses.h"
-struct tui_asm_line
+struct tui_asm_line
{
CORE_ADDR addr;
std::string addr_string;
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. */
+/* Function to disassemble up to COUNT instructions starting from address
+ PC into the ASM_LINES vector (which will be emptied of any previous
+ contents). Return the address of the COUNT'th instruction after pc.
+ When ADDR_SIZE is non-null then place the maximum size of an address and
+ label into the value pointed to by ADDR_SIZE, and set the addr_size
+ field on each item in ASM_LINES, otherwise the addr_size fields within
+ ASM_LINES are undefined.
+
+ It is worth noting that ASM_LINES might not have COUNT entries when this
+ function returns. If the disassembly is truncated for some other
+ reason, for example, we hit invalid memory, then ASM_LINES can have
+ fewer entries than requested. */
static CORE_ADDR
tui_disassemble (struct gdbarch *gdbarch,
std::vector<tui_asm_line> &asm_lines,
- CORE_ADDR pc, int pos, int count,
+ CORE_ADDR pc, 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);
+ /* Must start with an empty list. */
+ asm_lines.clear ();
+
/* 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 ());
+ tui_asm_line tal;
+ CORE_ADDR orig_pc = pc;
+ try
+ {
+ pc = pc + gdb_print_insn (gdbarch, pc, &gdb_dis_out, NULL);
+ }
+ catch (const gdb_exception_error &except)
+ {
+ /* If PC points to an invalid address then we'll catch a
+ MEMORY_ERROR here, this should stop the disassembly, but
+ otherwise is fine. */
+ if (except.error != MEMORY_ERROR)
+ throw;
+ return pc;
+ }
+
+ /* Capture the disassembled instruction. */
+ tal.insn = std::move (gdb_dis_out.string ());
+ gdb_dis_out.clear ();
+
+ /* And capture the address the instruction is at. */
+ tal.addr = orig_pc;
+ print_address (gdbarch, orig_pc, &gdb_dis_out);
+ tal.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);
+ new_size = len_without_escapes (tal.addr_string);
else
- new_size = asm_lines[pos + i].addr_string.size ();
+ new_size = tal.addr_string.size ();
*addr_size = std::max (*addr_size, new_size);
- asm_lines[pos + i].addr_size = new_size;
+ tal.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 ();
+ asm_lines.push_back (std::move (tal));
}
return pc;
}
+/* Look backward from ADDR for an address from which we can start
+ disassembling, this needs to be something we can be reasonably
+ confident will fall on an instruction boundary. We use msymbol
+ addresses, or the start of a section. */
+
+static CORE_ADDR
+tui_find_backward_disassembly_start_address (CORE_ADDR addr)
+{
+ struct bound_minimal_symbol msym, msym_prev;
+
+ msym = lookup_minimal_symbol_by_pc_section (addr - 1, nullptr,
+ lookup_msym_prefer::TEXT,
+ &msym_prev);
+ if (msym.minsym != nullptr)
+ return BMSYMBOL_VALUE_ADDRESS (msym);
+ else if (msym_prev.minsym != nullptr)
+ return BMSYMBOL_VALUE_ADDRESS (msym_prev);
+
+ /* Find the section that ADDR is in, and look for the start of the
+ section. */
+ struct obj_section *section = find_pc_section (addr);
+ if (section != NULL)
+ return obj_section_addr (section);
+
+ return addr;
+}
+
/* Find the disassembly address that corresponds to FROM lines above
or below the PC. Variable sized instructions are taken into
account by the algorithm. */
int max_lines;
max_lines = (from > 0) ? from : - from;
- if (max_lines <= 1)
+ if (max_lines == 0)
return pc;
- std::vector<tui_asm_line> asm_lines (max_lines);
+ std::vector<tui_asm_line> asm_lines;
new_low = pc;
if (from > 0)
{
- tui_disassemble (gdbarch, asm_lines, pc, 0, max_lines);
- new_low = asm_lines[max_lines - 1].addr;
+ /* Always disassemble 1 extra instruction here, then if the last
+ instruction fails to disassemble we will take the address of the
+ previous instruction that did disassemble as the result. */
+ tui_disassemble (gdbarch, asm_lines, pc, max_lines + 1);
+ new_low = asm_lines.back ().addr;
}
else
{
+ /* In order to disassemble backwards we need to find a suitable
+ address to start disassembling from and then work forward until we
+ re-find the address we're currently at. We can then figure out
+ which address will be at the top of the TUI window after our
+ backward scroll. During our backward disassemble we need to be
+ able to distinguish between the case where the last address we
+ _can_ disassemble is ADDR, and the case where the disassembly
+ just happens to stop at ADDR, for this reason we increase
+ MAX_LINES by one. */
+ max_lines++;
+
+ /* When we disassemble a series of instructions this will hold the
+ address of the last instruction disassembled. */
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);
+
+ /* And this will hold the address of the next instruction that would
+ have been disassembled. */
+ CORE_ADDR next_addr;
+
+ /* As we search backward if we find an address that looks like a
+ promising starting point then we record it in this structure. If
+ the next address we try is not a suitable starting point then we
+ will fall back to the address held here. */
+ gdb::optional<CORE_ADDR> possible_new_low;
+
+ /* The previous value of NEW_LOW so we know if the new value is
+ different or not. */
+ CORE_ADDR prev_low;
+
+ do
+ {
+ /* Find an address from which we can start disassembling. */
+ prev_low = new_low;
+ new_low = tui_find_backward_disassembly_start_address (new_low);
+
+ /* Disassemble forward. */
+ next_addr = tui_disassemble (gdbarch, asm_lines, new_low, max_lines);
+ last_addr = asm_lines.back ().addr;
+
+ /* If disassembling from the current value of NEW_LOW reached PC
+ (or went past it) then this would do as a starting point if we
+ can't find anything better, so remember it. */
+ if (last_addr >= pc && new_low != prev_low
+ && asm_lines.size () >= max_lines)
+ possible_new_low.emplace (new_low);
+
+ /* Continue searching until we find a value of NEW_LOW from which
+ disassembling MAX_LINES instructions doesn't reach PC. We
+ know this means we can find the required number of previous
+ instructions then. */
+ }
+ while ((last_addr > pc
+ || (last_addr == pc && asm_lines.size () < max_lines))
+ && new_low != prev_low);
+
+ /* If we failed to disassemble the required number of lines then the
+ following walk forward is not going to work, it assumes that
+ ASM_LINES contains exactly MAX_LINES entries. Instead we should
+ consider falling back to a previous possible start address in
+ POSSIBLE_NEW_LOW. */
+ if (asm_lines.size () < max_lines)
+ {
+ if (!possible_new_low.has_value ())
+ return new_low;
+
+ /* Take the best possible match we have. */
+ new_low = *possible_new_low;
+ next_addr = tui_disassemble (gdbarch, asm_lines, new_low, max_lines);
+ last_addr = asm_lines.back ().addr;
+ gdb_assert (asm_lines.size () >= max_lines);
+ }
/* 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). */
+ int pos = max_lines - 1;
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);
-
+ CORE_ADDR old_next_addr = next_addr;
+ std::vector<tui_asm_line> single_asm_line;
+ next_addr = tui_disassemble (gdbarch, single_asm_line,
+ next_addr, 1);
/* If there are some problems while disassembling exit. */
- if (next_addr <= last_addr)
- break;
- last_addr = next_addr;
- } while (last_addr <= pc);
+ if (next_addr <= old_next_addr)
+ return pc;
+ gdb_assert (single_asm_line.size () == 1);
+ asm_lines[pos] = single_asm_line[0];
+ } while (next_addr <= pc);
pos++;
if (pos >= max_lines)
pos = 0;
new_low = asm_lines[pos].addr;
+
+ /* When scrolling backward the addresses should move backward, or at
+ the very least stay the same if we are at the first address that
+ can be disassembled. */
+ gdb_assert (new_low <= pc);
}
return new_low;
}
/* Function to set the disassembly window's content. */
-enum tui_status
+bool
tui_disasm_window::set_contents (struct gdbarch *arch,
- struct symtab *s,
- struct tui_line_or_address line_or_addr)
+ const struct symtab_and_line &sal)
{
int i;
- int offset = horizontal_offset;
+ int offset = m_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;
- gdb_assert (line_or_addr.loa == LOA_ADDRESS);
- CORE_ADDR pc = line_or_addr.u.addr;
+ CORE_ADDR pc = sal.pc;
if (pc == 0)
- return TUI_FAILURE;
+ return false;
- gdbarch = arch;
- start_line_or_addr.loa = LOA_ADDRESS;
- start_line_or_addr.u.addr = pc;
+ m_gdbarch = arch;
+ m_start_line_or_addr.loa = LOA_ADDRESS;
+ m_start_line_or_addr.u.addr = pc;
cur_pc = locator->addr;
/* Window size, excluding highlight box. */
line_width = width - TUI_EXECINFO_SIZE - 2;
/* Get temporary table that will hold all strings (addr & insn). */
- std::vector<tui_asm_line> asm_lines (max_lines);
+ std::vector<tui_asm_line> asm_lines;
size_t addr_size = 0;
- tui_disassemble (gdbarch, asm_lines, pc, 0, max_lines, &addr_size);
+ tui_disassemble (m_gdbarch, asm_lines, pc, 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);
+ m_content.resize (max_lines);
for (i = 0; i < max_lines; i++)
{
- tui_source_element *src = &content[i];
+ tui_source_element *src = &m_content[i];
+
+ std::string line;
+ CORE_ADDR addr;
- std::string line
- = (asm_lines[i].addr_string
- + n_spaces (insn_pos - asm_lines[i].addr_size)
- + asm_lines[i].insn);
+ if (i < asm_lines.size ())
+ {
+ line
+ = (asm_lines[i].addr_string
+ + n_spaces (insn_pos - asm_lines[i].addr_size)
+ + asm_lines[i].insn);
+ addr = asm_lines[i].addr;
+ }
+ else
+ {
+ line = "";
+ addr = 0;
+ }
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;
+ src->line_or_addr.u.addr = addr;
+ src->is_exec_point = (addr == cur_pc && line.size () > 0);
}
- return TUI_SUCCESS;
+ return true;
}
-/* Function to display the disassembly window with disassembled code. */
-void
-tui_show_disassem (struct gdbarch *gdbarch, CORE_ADDR start_addr)
-{
- struct symtab *s = find_pc_line_symtab (start_addr);
- struct tui_win_info *win_with_focus = tui_win_with_focus ();
- struct tui_line_or_address val;
-
- gdb_assert (TUI_DISASM_WIN != nullptr && TUI_DISASM_WIN->is_visible ());
-
- val.loa = LOA_ADDRESS;
- val.u.addr = start_addr;
- TUI_DISASM_WIN->update_source_window (gdbarch, s, val);
-
- /* If the focus was in the src win, put it in the asm win, if the
- source view isn't split. */
- if (tui_current_layout () != SRC_DISASSEM_COMMAND
- && win_with_focus == TUI_SRC_WIN)
- tui_set_win_focus_to (TUI_DISASM_WIN);
-}
-
-
-/* Function to display the disassembly window. */
-void
-tui_show_disassem_and_update_source (struct gdbarch *gdbarch,
- CORE_ADDR start_addr)
-{
- struct symtab_and_line sal;
-
- tui_show_disassem (gdbarch, start_addr);
- if (tui_current_layout () == SRC_DISASSEM_COMMAND)
- {
- struct tui_line_or_address val;
-
- /* Update what is in the source window if it is displayed too,
- note that it follows what is in the disassembly window and
- visa-versa. */
- sal = find_pc_line (start_addr, 0);
- val.loa = LOA_LINE;
- val.u.line_no = sal.line;
- TUI_SRC_WIN->update_source_window (gdbarch, sal.symtab, val);
- if (sal.symtab)
- {
- set_current_source_symtab_and_line (sal);
- tui_update_locator_fullname (symtab_to_fullname (sal.symtab));
- }
- else
- tui_update_locator_fullname ("?");
- }
-}
-
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;
+ CORE_ADDR addr = 0;
locator = tui_locator_win_info_ptr ();
if (locator->addr == 0)
{
- struct bound_minimal_symbol main_symbol;
-
- /* Find address of the start of program.
- Note: this should be language specific. */
- main_symbol = lookup_minimal_symbol ("main", NULL, NULL);
- if (main_symbol.minsym == 0)
- main_symbol = lookup_minimal_symbol ("MAIN", NULL, NULL);
- if (main_symbol.minsym == 0)
- main_symbol = lookup_minimal_symbol ("_start", NULL, NULL);
- if (main_symbol.minsym)
- addr = BMSYMBOL_VALUE_ADDRESS (main_symbol);
- else
- 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. */
{
/* 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;
+ if (TUI_DISASM_WIN != NULL)
+ pos = TUI_DISASM_WIN->height;
else if (TUI_CMD_WIN == NULL)
pos = tui_term_height () / 2 - 2;
else
void
tui_disasm_window::do_scroll_vertical (int num_to_scroll)
{
- if (!content.empty ())
+ if (!m_content.empty ())
{
CORE_ADDR pc;
- struct tui_line_or_address val;
- pc = content[0].line_or_addr.u.addr;
- if (num_to_scroll >= 0)
- num_to_scroll++;
- else
- --num_to_scroll;
+ pc = m_start_line_or_addr.u.addr;
- val.loa = LOA_ADDRESS;
- val.u.addr = tui_find_disassembly_address (gdbarch, pc, num_to_scroll);
- update_source_window_as_is (gdbarch, NULL, val);
+ symtab_and_line sal {};
+ sal.pspace = current_program_space;
+ sal.pc = tui_find_disassembly_address (m_gdbarch, pc, num_to_scroll);
+ update_source_window_as_is (m_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);
+ return (m_content[line_no].line_or_addr.loa == LOA_ADDRESS
+ && m_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;
+ if (m_content.size () < SCROLL_THRESHOLD)
+ return false;
- int i = 0;
- while (i < content.size () - threshold && !is_displayed)
+ for (size_t i = 0; i < m_content.size () - SCROLL_THRESHOLD; ++i)
{
- is_displayed
- = (content[i].line_or_addr.loa == LOA_ADDRESS
- && content[i].line_or_addr.u.addr == addr);
- i++;
+ if (m_content[i].line_or_addr.loa == LOA_ADDRESS
+ && m_content[i].line_or_addr.u.addr == addr)
+ return true;
}
- return is_displayed;
+ return false;
}
void
-tui_disasm_window::maybe_update (struct frame_info *fi, symtab_and_line sal,
- int line_no, CORE_ADDR addr)
+tui_disasm_window::maybe_update (struct frame_info *fi, symtab_and_line sal)
{
CORE_ADDR low;
- if (find_pc_partial_function (get_frame_pc (fi),
- NULL, &low, NULL) == 0)
+ 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 = get_frame_pc (fi);
+ low = sal.pc;
}
else
- low = tui_get_low_disassembly_address (get_frame_arch (fi),
- low, get_frame_pc (fi));
+ 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 (addr))
- update_source_window (get_frame_arch (fi), sal.symtab, a);
+ if (!addr_is_displayed (sal.pc))
+ {
+ sal.pc = low;
+ update_source_window (frame_arch, sal);
+ }
else
{
- a.u.addr = addr;
+ a.u.addr = sal.pc;
set_is_exec_point_at (a);
}
}
+
+void
+tui_disasm_window::display_start_addr (struct gdbarch **gdbarch_p,
+ CORE_ADDR *addr_p)
+{
+ *gdbarch_p = m_gdbarch;
+ *addr_p = m_start_line_or_addr.u.addr;
+}
projects / deliverable / binutils-gdb.git / blobdiff