binutils-gdb/gdb/disasm.h
Andrew Burgess e867795e8b gdb: use python to colorize disassembler output
This commit adds styling support to the disassembler output, as such
two new commands are added to GDB:

  set style disassembler enabled on|off
  show style disassembler enabled

In this commit I make use of the Python Pygments package to provide
the styling.  I did investigate making use of libsource-highlight,
however, I found the highlighting results to be inferior to those of
Pygments; only some mnemonics were highlighted, and highlighting of
register names such as r9d and r8d (on x86-64) was incorrect.

To enable disassembler highlighting via Pygments, I've added a new
extension language hook, which is then implemented for Python.  This
hook is very similar to the existing hook for source code
colorization.

One possibly odd choice I made with the new hook is to pass a
gdb.Architecture through, even though this is currently unused.  The
reason this argument is not used is that, currently, styling is
performed identically for all architectures.

However, even though the Python function used to perform styling of
disassembly output is not part of any documented API, I don't want
to close the door on a user overriding this function to provide
architecture specific styling.  To do this, the user would inevitably
require access to the gdb.Architecture, and so I decided to add this
field now.

The styling is applied within gdb_disassembler::print_insn, to achieve
this, gdb_disassembler now writes its output into a temporary buffer,
styling is then applied to the contents of this buffer.  Finally the
gdb_disassembler buffer is copied out to its final destination stream.

There's a new test to check that the disassembler output includes some
escape sequences, though I don't check for specific colours; the
precise colors will depend on which instructions are in the
disassembler output, and, I guess, how pygments is configured.

The only negative change with this commit is how we currently style
addresses in GDB.

Currently, when the disassembler wants to print an address, we call
back into GDB, and GDB prints the address value using the `address`
styling, and the symbol name using `function` styling.  After this
commit, if pygments is used, then all disassembler styling is done
through pygments, and this include the address and symbol name parts
of the disassembler output.

I don't know how much of an issue this will be for people.  There's
already some precedent for this in GDB when we look at source styling.
For example, function names in styled source listings are not styled
using the `function` style, but instead, either GNU Source Highlight,
or pygments gets to decide how the function name should be styled.

If the Python pygments library is not present then GDB will continue
to behave as it always has, the disassembler output is mostly
unstyled, but the address and symbols are styled using the `address`
and `function` styles, as they are today.

However, if the user does `set style disassembler enabled off`, then
all disassembler styling is switched off.  This obviously covers the
use of pygments, but also includes the minimal styling done by GDB
when pygments is not available.
2022-02-14 09:53:04 +00:00

209 lines
6.8 KiB
C++

/* Disassemble support for GDB.
Copyright (C) 2002-2022 Free Software Foundation, Inc.
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 <http://www.gnu.org/licenses/>. */
#ifndef DISASM_H
#define DISASM_H
#include "dis-asm.h"
#include "gdbsupport/enum-flags.h"
enum gdb_disassembly_flag
{
DISASSEMBLY_SOURCE_DEPRECATED = (0x1 << 0),
DISASSEMBLY_RAW_INSN = (0x1 << 1),
DISASSEMBLY_OMIT_FNAME = (0x1 << 2),
DISASSEMBLY_FILENAME = (0x1 << 3),
DISASSEMBLY_OMIT_PC = (0x1 << 4),
DISASSEMBLY_SOURCE = (0x1 << 5),
DISASSEMBLY_SPECULATIVE = (0x1 << 6),
};
DEF_ENUM_FLAGS_TYPE (enum gdb_disassembly_flag, gdb_disassembly_flags);
struct gdbarch;
struct ui_out;
struct ui_file;
class gdb_disassembler
{
using di_read_memory_ftype = decltype (disassemble_info::read_memory_func);
public:
gdb_disassembler (struct gdbarch *gdbarch, struct ui_file *file)
: gdb_disassembler (gdbarch, file, dis_asm_read_memory)
{}
~gdb_disassembler ();
DISABLE_COPY_AND_ASSIGN (gdb_disassembler);
int print_insn (CORE_ADDR memaddr, int *branch_delay_insns = NULL);
/* Return the gdbarch of gdb_disassembler. */
struct gdbarch *arch ()
{ return m_gdbarch; }
protected:
gdb_disassembler (struct gdbarch *gdbarch, struct ui_file *file,
di_read_memory_ftype func);
struct ui_file *stream ()
{ return (struct ui_file *) m_di.stream; }
private:
struct gdbarch *m_gdbarch;
/* Stores data required for disassembling instructions in
opcodes. */
struct disassemble_info m_di;
/* If we own the string in `m_di.disassembler_options', we do so
using this field. */
std::string m_disassembler_options_holder;
/* This member variable is given a value by calling dis_asm_memory_error.
If after calling into the libopcodes disassembler we get back a
negative value (which indicates an error), then, if this variable has
a value, we report a memory error to the user, otherwise, we report a
non-memory error. */
gdb::optional<CORE_ADDR> m_err_memaddr;
/* Disassembler output is built up into this buffer. Whether this
string_file is created with styling support or not depends on the
value of use_ext_lang_colorization_p, as well as whether disassembler
styling in general is turned on, and also, whether *m_dest supports
styling or not. */
string_file m_buffer;
/* The stream to which disassembler output will be written. */
ui_file *m_dest;
/* When true, m_buffer will be created without styling support,
otherwise, m_buffer will be created with styling support.
This field will initially be true, but will be set to false if
ext_lang_colorize_disasm fails to add styling at any time.
If the extension language is going to add the styling then m_buffer
should be created without styling support, the extension language will
then add styling at the end of the disassembly process.
If the extension language is not going to add the styling, then we
create m_buffer with styling support, and GDB will add minimal styling
(currently just to addresses and symbols) as it goes. */
static bool use_ext_lang_colorization_p;
static int dis_asm_fprintf (void *stream, const char *format, ...)
ATTRIBUTE_PRINTF(2,3);
static int dis_asm_read_memory (bfd_vma memaddr, gdb_byte *myaddr,
unsigned int len,
struct disassemble_info *info);
static void dis_asm_memory_error (int err, bfd_vma memaddr,
struct disassemble_info *info);
static void dis_asm_print_address (bfd_vma addr,
struct disassemble_info *info);
};
/* An instruction to be disassembled. */
struct disasm_insn
{
/* The address of the memory containing the instruction. */
CORE_ADDR addr;
/* An optional instruction number. If non-zero, it is printed first. */
unsigned int number;
/* True if the instruction was executed speculatively. */
unsigned int is_speculative:1;
};
extern void gdb_disassembly (struct gdbarch *gdbarch, struct ui_out *uiout,
gdb_disassembly_flags flags, int how_many,
CORE_ADDR low, CORE_ADDR high);
/* Print the instruction at address MEMADDR in debugged memory,
on STREAM. Returns the length of the instruction, in bytes,
and, if requested, the number of branch delay slot instructions. */
extern int gdb_print_insn (struct gdbarch *gdbarch, CORE_ADDR memaddr,
struct ui_file *stream, int *branch_delay_insns);
/* Class used to pretty-print instructions. */
class gdb_pretty_print_disassembler
{
public:
explicit gdb_pretty_print_disassembler (struct gdbarch *gdbarch,
struct ui_out *uiout)
: m_uiout (uiout),
m_insn_stb (uiout->can_emit_style_escape ()),
m_di (gdbarch, &m_insn_stb)
{}
/* Prints the instruction INSN into the saved ui_out and returns the
length of the printed instruction in bytes. */
int pretty_print_insn (const struct disasm_insn *insn,
gdb_disassembly_flags flags);
private:
/* Returns the architecture used for disassembling. */
struct gdbarch *arch () { return m_di.arch (); }
/* The ui_out that is used by pretty_print_insn. */
struct ui_out *m_uiout;
/* The buffer used to build the instruction string. The
disassembler is initialized with this stream. */
string_file m_insn_stb;
/* The disassembler used for instruction printing. */
gdb_disassembler m_di;
/* The buffer used to build the raw opcodes string. */
string_file m_opcode_stb;
};
/* Return the length in bytes of the instruction at address MEMADDR in
debugged memory. */
extern int gdb_insn_length (struct gdbarch *gdbarch, CORE_ADDR memaddr);
/* Return the length in bytes of INSN, originally at MEMADDR. MAX_LEN
is the size of the buffer containing INSN. */
extern int gdb_buffered_insn_length (struct gdbarch *gdbarch,
const gdb_byte *insn, int max_len,
CORE_ADDR memaddr);
/* Returns GDBARCH's disassembler options. */
extern char *get_disassembler_options (struct gdbarch *gdbarch);
/* Sets the active gdbarch's disassembler options to OPTIONS. */
extern void set_disassembler_options (const char *options);
/* Setup DINFO with its output function and output stream setup so that
nothing is printed while disassembling. */
extern void init_disassemble_info_for_no_printing
(struct disassemble_info *dinfo);
#endif