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# Python hooks for gdb for debugging GCC
# Copyright (C) 2013-2022 Free Software Foundation, Inc.
# Contributed by David Malcolm <dmalcolm@redhat.com>
# This file is part of GCC.
# GCC 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, or (at your option) any later
# version.
# GCC 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 GCC; see the file COPYING3. If not see
# <http://www.gnu.org/licenses/>.
"""
Enabling the debugging hooks
----------------------------
gcc/configure (from configure.ac) generates a .gdbinit within the "gcc"
subdirectory of the build directory, and when run by gdb, this imports
gcc/gdbhooks.py from the source directory, injecting useful Python code
into gdb.
You may see a message from gdb of the form:
"path-to-build/gcc/.gdbinit" auto-loading has been declined by your `auto-load safe-path'
as a protection against untrustworthy python scripts. See
http://sourceware.org/gdb/onlinedocs/gdb/Auto_002dloading-safe-path.html
The fix is to mark the paths of the build/gcc directory as trustworthy.
An easy way to do so is by adding the following to your ~/.gdbinit script:
add-auto-load-safe-path /absolute/path/to/build/gcc
for the build directories for your various checkouts of gcc.
If it's working, you should see the message:
Successfully loaded GDB hooks for GCC
as gdb starts up.
During development, I've been manually invoking the code in this way, as a
precanned way of printing a variety of different kinds of value:
gdb \
-ex "break expand_gimple_stmt" \
-ex "run" \
-ex "bt" \
--args \
./cc1 foo.c -O3
Examples of output using the pretty-printers
--------------------------------------------
Pointer values are generally shown in the form:
<type address extra_info>
For example, an opt_pass* might appear as:
(gdb) p pass
$2 = <opt_pass* 0x188b600 "expand"(170)>
The name of the pass is given ("expand"), together with the
static_pass_number.
Note that you can dereference the pointer in the normal way:
(gdb) p *pass
$4 = {type = RTL_PASS, name = 0x120a312 "expand",
[etc, ...snipped...]
and you can suppress pretty-printers using /r (for "raw"):
(gdb) p /r pass
$3 = (opt_pass *) 0x188b600
Basic blocks are shown with their index in parentheses, apart from the
CFG's entry and exit blocks, which are given as "ENTRY" and "EXIT":
(gdb) p bb
$9 = <basic_block 0x7ffff041f1a0 (2)>
(gdb) p cfun->cfg->x_entry_block_ptr
$10 = <basic_block 0x7ffff041f0d0 (ENTRY)>
(gdb) p cfun->cfg->x_exit_block_ptr
$11 = <basic_block 0x7ffff041f138 (EXIT)>
CFG edges are shown with the src and dest blocks given in parentheses:
(gdb) p e
$1 = <edge 0x7ffff043f118 (ENTRY -> 6)>
Tree nodes are printed using Python code that emulates print_node_brief,
running in gdb, rather than in the inferior:
(gdb) p cfun->decl
$1 = <function_decl 0x7ffff0420b00 foo>
For usability, the type is printed first (e.g. "function_decl"), rather
than just "tree".
RTL expressions use a kludge: they are pretty-printed by injecting
calls into print-rtl.c into the inferior:
Value returned is $1 = (note 9 8 10 [bb 3] NOTE_INSN_BASIC_BLOCK)
(gdb) p $1
$2 = (note 9 8 10 [bb 3] NOTE_INSN_BASIC_BLOCK)
(gdb) p /r $1
$3 = (rtx_def *) 0x7ffff043e140
This won't work for coredumps, and probably in other circumstances, but
it's a quick way of getting lots of debuggability quickly.
Callgraph nodes are printed with the name of the function decl, if
available:
(gdb) frame 5
#5 0x00000000006c288a in expand_function (node=<cgraph_node* 0x7ffff0312720 "foo"/12345>) at ../../src/gcc/cgraphunit.c:1594
1594 execute_pass_list (g->get_passes ()->all_passes);
(gdb) p node
$1 = <cgraph_node* 0x7ffff0312720 "foo"/12345>
Similarly for symtab_node and varpool_node classes.
Cgraph edges are printed with the name of caller and callee:
(gdb) p this->callees
$4 = <cgraph_edge* 0x7fffe25aa000 (<cgraph_node * 0x7fffe62b22e0 "_GLOBAL__sub_I__ZN5Pooma5pinfoE"/19660> -> <cgraph_node * 0x7fffe620f730 "__static_initialization_and_destruction_1"/19575>)>
IPA reference follow very similar format:
(gdb) Value returned is $5 = <ipa_ref* 0x7fffefcb80c8 (<symtab_node * 0x7ffff562f000 "__dt_base "/875> -> <symtab_node * 0x7fffe795f000 "_ZTVN6Smarts8RunnableE"/16056>:IPA_REF_ADDR)>
vec<> pointers are printed as the address followed by the elements in
braces. Here's a length 2 vec:
(gdb) p bb->preds
$18 = 0x7ffff0428b68 = {<edge 0x7ffff044d380 (3 -> 5)>, <edge 0x7ffff044d3b8 (4 -> 5)>}
and here's a length 1 vec:
(gdb) p bb->succs
$19 = 0x7ffff0428bb8 = {<edge 0x7ffff044d3f0 (5 -> EXIT)>}
You cannot yet use array notation [] to access the elements within the
vector: attempting to do so instead gives you the vec itself (for vec[0]),
or a (probably) invalid cast to vec<> for the memory after the vec (for
vec[1] onwards).
Instead (for now) you must access m_vecdata:
(gdb) p bb->preds->m_vecdata[0]
$20 = <edge 0x7ffff044d380 (3 -> 5)>
(gdb) p bb->preds->m_vecdata[1]
$21 = <edge 0x7ffff044d3b8 (4 -> 5)>
"""
import os.path
import re
import sys
import tempfile
import gdb
import gdb.printing
import gdb.types
# Convert "enum tree_code" (tree.def and tree.h) to a dict:
tree_code_dict = gdb.types.make_enum_dict(gdb.lookup_type('enum tree_code'))
# ...and look up specific values for use later:
IDENTIFIER_NODE = tree_code_dict['IDENTIFIER_NODE']
TYPE_DECL = tree_code_dict['TYPE_DECL']
SSA_NAME = tree_code_dict['SSA_NAME']
# Similarly for "enum tree_code_class" (tree.h):
tree_code_class_dict = gdb.types.make_enum_dict(gdb.lookup_type('enum tree_code_class'))
tcc_type = tree_code_class_dict['tcc_type']
tcc_declaration = tree_code_class_dict['tcc_declaration']
# Python3 has int() with arbitrary precision (bignum). Python2 int() is 32-bit
# on 32-bit hosts but remote targets may have 64-bit pointers there; Python2
# long() is always 64-bit but Python3 no longer has anything named long.
def intptr(gdbval):
return long(gdbval) if sys.version_info.major == 2 else int(gdbval)
class Tree:
"""
Wrapper around a gdb.Value for a tree, with various methods
corresponding to macros in gcc/tree.h
"""
def __init__(self, gdbval):
self.gdbval = gdbval
def is_nonnull(self):
return intptr(self.gdbval)
def TREE_CODE(self):
"""
Get gdb.Value corresponding to TREE_CODE (self)
as per:
#define TREE_CODE(NODE) ((enum tree_code) (NODE)->base.code)
"""
return self.gdbval['base']['code']
def DECL_NAME(self):
"""
Get Tree instance corresponding to DECL_NAME (self)
"""
return Tree(self.gdbval['decl_minimal']['name'])
def TYPE_NAME(self):
"""
Get Tree instance corresponding to result of TYPE_NAME (self)
"""
return Tree(self.gdbval['type_common']['name'])
def IDENTIFIER_POINTER(self):
"""
Get str correspoinding to result of IDENTIFIER_NODE (self)
"""
return self.gdbval['identifier']['id']['str'].string()
class TreePrinter:
"Prints a tree"
def __init__ (self, gdbval):
self.gdbval = gdbval
self.node = Tree(gdbval)
def to_string (self):
# like gcc/print-tree.c:print_node_brief
# #define TREE_CODE(NODE) ((enum tree_code) (NODE)->base.code)
# tree_code_name[(int) TREE_CODE (node)])
if intptr(self.gdbval) == 0:
return '<tree 0x0>'
val_TREE_CODE = self.node.TREE_CODE()
# extern const enum tree_code_class tree_code_type[];
# #define TREE_CODE_CLASS(CODE) tree_code_type[(int) (CODE)]
if val_TREE_CODE == 0xa5a5:
return '<ggc_freed 0x%x>' % intptr(self.gdbval)
val_tree_code_type = gdb.parse_and_eval('tree_code_type')
val_tclass = val_tree_code_type[val_TREE_CODE]
val_tree_code_name = gdb.parse_and_eval('tree_code_name')
val_code_name = val_tree_code_name[intptr(val_TREE_CODE)]
#print(val_code_name.string())
try:
result = '<%s 0x%x' % (val_code_name.string(), intptr(self.gdbval))
except:
return '<tree 0x%x>' % intptr(self.gdbval)
if intptr(val_tclass) == tcc_declaration:
tree_DECL_NAME = self.node.DECL_NAME()
if tree_DECL_NAME.is_nonnull():
result += ' %s' % tree_DECL_NAME.IDENTIFIER_POINTER()
else:
pass # TODO: labels etc
elif intptr(val_tclass) == tcc_type:
tree_TYPE_NAME = Tree(self.gdbval['type_common']['name'])
if tree_TYPE_NAME.is_nonnull():
if tree_TYPE_NAME.TREE_CODE() == IDENTIFIER_NODE:
result += ' %s' % tree_TYPE_NAME.IDENTIFIER_POINTER()
elif tree_TYPE_NAME.TREE_CODE() == TYPE_DECL:
if tree_TYPE_NAME.DECL_NAME().is_nonnull():
result += ' %s' % tree_TYPE_NAME.DECL_NAME().IDENTIFIER_POINTER()
if self.node.TREE_CODE() == IDENTIFIER_NODE:
result += ' %s' % self.node.IDENTIFIER_POINTER()
elif self.node.TREE_CODE() == SSA_NAME:
result += ' %u' % self.gdbval['base']['u']['version']
# etc
result += '>'
return result
######################################################################
# Callgraph pretty-printers
######################################################################
class SymtabNodePrinter:
def __init__(self, gdbval):
self.gdbval = gdbval
def to_string (self):
t = str(self.gdbval.type)
result = '<%s 0x%x' % (t, intptr(self.gdbval))
if intptr(self.gdbval):
# symtab_node::name calls lang_hooks.decl_printable_name
# default implementation (lhd_decl_printable_name) is:
# return IDENTIFIER_POINTER (DECL_NAME (decl));
tree_decl = Tree(self.gdbval['decl'])
result += ' "%s"/%d' % (tree_decl.DECL_NAME().IDENTIFIER_POINTER(), self.gdbval['order'])
result += '>'
return result
class CgraphEdgePrinter:
def __init__(self, gdbval):
self.gdbval = gdbval
def to_string (self):
result = '<cgraph_edge* 0x%x' % intptr(self.gdbval)
if intptr(self.gdbval):
src = SymtabNodePrinter(self.gdbval['caller']).to_string()
dest = SymtabNodePrinter(self.gdbval['callee']).to_string()
result += ' (%s -> %s)' % (src, dest)
result += '>'
return result
class IpaReferencePrinter:
def __init__(self, gdbval):
self.gdbval = gdbval
def to_string (self):
result = '<ipa_ref* 0x%x' % intptr(self.gdbval)
if intptr(self.gdbval):
src = SymtabNodePrinter(self.gdbval['referring']).to_string()
dest = SymtabNodePrinter(self.gdbval['referred']).to_string()
result += ' (%s -> %s:%s)' % (src, dest, str(self.gdbval['use']))
result += '>'
return result
######################################################################
# Dwarf DIE pretty-printers
######################################################################
class DWDieRefPrinter:
def __init__(self, gdbval):
self.gdbval = gdbval
def to_string (self):
if intptr(self.gdbval) == 0:
return '<dw_die_ref 0x0>'
result = '<dw_die_ref 0x%x' % intptr(self.gdbval)
result += ' %s' % self.gdbval['die_tag']
if intptr(self.gdbval['die_parent']) != 0:
result += ' <parent=0x%x %s>' % (intptr(self.gdbval['die_parent']),
self.gdbval['die_parent']['die_tag'])
result += '>'
return result
######################################################################
class GimplePrinter:
def __init__(self, gdbval):
self.gdbval = gdbval
def to_string (self):
if intptr(self.gdbval) == 0:
return '<gimple 0x0>'
val_gimple_code = self.gdbval['code']
val_gimple_code_name = gdb.parse_and_eval('gimple_code_name')
val_code_name = val_gimple_code_name[intptr(val_gimple_code)]
result = '<%s 0x%x' % (val_code_name.string(),
intptr(self.gdbval))
result += '>'
return result
######################################################################
# CFG pretty-printers
######################################################################
def bb_index_to_str(index):
if index == 0:
return 'ENTRY'
elif index == 1:
return 'EXIT'
else:
return '%i' % index
class BasicBlockPrinter:
def __init__(self, gdbval):
self.gdbval = gdbval
def to_string (self):
result = '<basic_block 0x%x' % intptr(self.gdbval)
if intptr(self.gdbval):
result += ' (%s)' % bb_index_to_str(intptr(self.gdbval['index']))
result += '>'
return result
class CfgEdgePrinter:
def __init__(self, gdbval):
self.gdbval = gdbval
def to_string (self):
result = '<edge 0x%x' % intptr(self.gdbval)
if intptr(self.gdbval):
src = bb_index_to_str(intptr(self.gdbval['src']['index']))
dest = bb_index_to_str(intptr(self.gdbval['dest']['index']))
result += ' (%s -> %s)' % (src, dest)
result += '>'
return result
######################################################################
class Rtx:
def __init__(self, gdbval):
self.gdbval = gdbval
def GET_CODE(self):
return self.gdbval['code']
def GET_RTX_LENGTH(code):
val_rtx_length = gdb.parse_and_eval('rtx_length')
return intptr(val_rtx_length[code])
def GET_RTX_NAME(code):
val_rtx_name = gdb.parse_and_eval('rtx_name')
return val_rtx_name[code].string()
def GET_RTX_FORMAT(code):
val_rtx_format = gdb.parse_and_eval('rtx_format')
return val_rtx_format[code].string()
class RtxPrinter:
def __init__(self, gdbval):
self.gdbval = gdbval
self.rtx = Rtx(gdbval)
def to_string (self):
"""
For now, a cheap kludge: invoke the inferior's print
function to get a string to use the user, and return an empty
string for gdb
"""
# We use print_inline_rtx to avoid a trailing newline
gdb.execute('call print_inline_rtx (stderr, (const_rtx) %s, 0)'
% intptr(self.gdbval))
return ''
# or by hand; based on gcc/print-rtl.c:print_rtx
result = ('<rtx_def 0x%x'
% (intptr(self.gdbval)))
code = self.rtx.GET_CODE()
result += ' (%s' % GET_RTX_NAME(code)
format_ = GET_RTX_FORMAT(code)
for i in range(GET_RTX_LENGTH(code)):
print(format_[i])
result += ')>'
return result
######################################################################
class PassPrinter:
def __init__(self, gdbval):
self.gdbval = gdbval
def to_string (self):
result = '<opt_pass* 0x%x' % intptr(self.gdbval)
if intptr(self.gdbval):
result += (' "%s"(%i)'
% (self.gdbval['name'].string(),
intptr(self.gdbval['static_pass_number'])))
result += '>'
return result
######################################################################
class VecPrinter:
# -ex "up" -ex "p bb->preds"
def __init__(self, gdbval):
self.gdbval = gdbval
def display_hint (self):
return 'array'
def to_string (self):
# A trivial implementation; prettyprinting the contents is done
# by gdb calling the "children" method below.
return '0x%x' % intptr(self.gdbval)
def children (self):
if intptr(self.gdbval) == 0:
return
m_vecpfx = self.gdbval['m_vecpfx']
m_num = m_vecpfx['m_num']
m_vecdata = self.gdbval['m_vecdata']
for i in range(m_num):
yield ('[%d]' % i, m_vecdata[i])
######################################################################
class MachineModePrinter:
def __init__(self, gdbval):
self.gdbval = gdbval
def to_string (self):
name = str(self.gdbval['m_mode'])
return name[2:] if name.startswith('E_') else name
######################################################################
class OptMachineModePrinter:
def __init__(self, gdbval):
self.gdbval = gdbval
def to_string (self):
name = str(self.gdbval['m_mode'])
if name == 'E_VOIDmode':
return '<None>'
return name[2:] if name.startswith('E_') else name
######################################################################
# TODO:
# * hashtab
# * location_t
class GdbSubprinter(gdb.printing.SubPrettyPrinter):
def __init__(self, name, class_):
super(GdbSubprinter, self).__init__(name)
self.class_ = class_
def handles_type(self, str_type):
raise NotImplementedError
class GdbSubprinterTypeList(GdbSubprinter):
"""
A GdbSubprinter that handles a specific set of types
"""
def __init__(self, str_types, name, class_):
super(GdbSubprinterTypeList, self).__init__(name, class_)
self.str_types = frozenset(str_types)
def handles_type(self, str_type):
return str_type in self.str_types
class GdbSubprinterRegex(GdbSubprinter):
"""
A GdbSubprinter that handles types that match a regex
"""
def __init__(self, regex, name, class_):
super(GdbSubprinterRegex, self).__init__(name, class_)
self.regex = re.compile(regex)
def handles_type(self, str_type):
return self.regex.match(str_type)
class GdbPrettyPrinters(gdb.printing.PrettyPrinter):
def __init__(self, name):
super(GdbPrettyPrinters, self).__init__(name, [])
def add_printer_for_types(self, types, name, class_):
self.subprinters.append(GdbSubprinterTypeList(types, name, class_))
def add_printer_for_regex(self, regex, name, class_):
self.subprinters.append(GdbSubprinterRegex(regex, name, class_))
def __call__(self, gdbval):
type_ = gdbval.type.unqualified()
str_type = str(type_)
for printer in self.subprinters:
if printer.enabled and printer.handles_type(str_type):
return printer.class_(gdbval)
# Couldn't find a pretty printer (or it was disabled):
return None
def build_pretty_printer():
pp = GdbPrettyPrinters('gcc')
pp.add_printer_for_types(['tree', 'const_tree'],
'tree', TreePrinter)
pp.add_printer_for_types(['cgraph_node *', 'varpool_node *', 'symtab_node *'],
'symtab_node', SymtabNodePrinter)
pp.add_printer_for_types(['cgraph_edge *'],
'cgraph_edge', CgraphEdgePrinter)
pp.add_printer_for_types(['ipa_ref *'],
'ipa_ref', IpaReferencePrinter)
pp.add_printer_for_types(['dw_die_ref'],
'dw_die_ref', DWDieRefPrinter)
pp.add_printer_for_types(['gimple', 'gimple *',
# Keep this in the same order as gimple.def:
'gimple_cond', 'const_gimple_cond',
'gimple_statement_cond *',
'gimple_debug', 'const_gimple_debug',
'gimple_statement_debug *',
'gimple_label', 'const_gimple_label',
'gimple_statement_label *',
'gimple_switch', 'const_gimple_switch',
'gimple_statement_switch *',
'gimple_assign', 'const_gimple_assign',
'gimple_statement_assign *',
'gimple_bind', 'const_gimple_bind',
'gimple_statement_bind *',
'gimple_phi', 'const_gimple_phi',
'gimple_statement_phi *'],
'gimple',
GimplePrinter)
pp.add_printer_for_types(['basic_block', 'basic_block_def *'],
'basic_block',
BasicBlockPrinter)
pp.add_printer_for_types(['edge', 'edge_def *'],
'edge',
CfgEdgePrinter)
pp.add_printer_for_types(['rtx_def *'], 'rtx_def', RtxPrinter)
pp.add_printer_for_types(['opt_pass *'], 'opt_pass', PassPrinter)
pp.add_printer_for_regex(r'vec<(\S+), (\S+), (\S+)> \*',
'vec',
VecPrinter)
pp.add_printer_for_regex(r'opt_mode<(\S+)>',
'opt_mode', OptMachineModePrinter)
pp.add_printer_for_types(['opt_scalar_int_mode',
'opt_scalar_float_mode',
'opt_scalar_mode'],
'opt_mode', OptMachineModePrinter)
pp.add_printer_for_regex(r'pod_mode<(\S+)>',
'pod_mode', MachineModePrinter)
pp.add_printer_for_types(['scalar_int_mode_pod',
'scalar_mode_pod'],
'pod_mode', MachineModePrinter)
for mode in ('scalar_mode', 'scalar_int_mode', 'scalar_float_mode',
'complex_mode'):
pp.add_printer_for_types([mode], mode, MachineModePrinter)
return pp
gdb.printing.register_pretty_printer(
gdb.current_objfile(),
build_pretty_printer(),
replace=True)
def find_gcc_source_dir():
# Use location of global "g" to locate the source tree
sym_g = gdb.lookup_global_symbol('g')
path = sym_g.symtab.filename # e.g. '../../src/gcc/context.h'
srcdir = os.path.split(path)[0] # e.g. '../../src/gcc'
return srcdir
class PassNames:
"""Parse passes.def, gathering a list of pass class names"""
def __init__(self):
srcdir = find_gcc_source_dir()
self.names = []
with open(os.path.join(srcdir, 'passes.def')) as f:
for line in f:
m = re.match('\s*NEXT_PASS \(([^,]+).*\);', line)
if m:
self.names.append(m.group(1))
class BreakOnPass(gdb.Command):
"""
A custom command for putting breakpoints on the execute hook of passes.
This is largely a workaround for issues with tab-completion in gdb when
setting breakpoints on methods on classes within anonymous namespaces.
Example of use: putting a breakpoint on "final"
(gdb) break-on-pass
Press <TAB>; it autocompletes to "pass_":
(gdb) break-on-pass pass_
Press <TAB>:
Display all 219 possibilities? (y or n)
Press "n"; then type "f":
(gdb) break-on-pass pass_f
Press <TAB> to autocomplete to pass classnames beginning with "pass_f":
pass_fast_rtl_dce pass_fold_builtins
pass_feedback_split_functions pass_forwprop
pass_final pass_fre
pass_fixup_cfg pass_free_cfg
Type "in<TAB>" to complete to "pass_final":
(gdb) break-on-pass pass_final
...and hit <RETURN>:
Breakpoint 6 at 0x8396ba: file ../../src/gcc/final.c, line 4526.
...and we have a breakpoint set; continue execution:
(gdb) cont
Continuing.
Breakpoint 6, (anonymous namespace)::pass_final::execute (this=0x17fb990) at ../../src/gcc/final.c:4526
4526 virtual unsigned int execute (function *) { return rest_of_handle_final (); }
"""
def __init__(self):
gdb.Command.__init__(self, 'break-on-pass', gdb.COMMAND_BREAKPOINTS)
self.pass_names = None
def complete(self, text, word):
# Lazily load pass names:
if not self.pass_names:
self.pass_names = PassNames()
return [name
for name in sorted(self.pass_names.names)
if name.startswith(text)]
def invoke(self, arg, from_tty):
sym = '(anonymous namespace)::%s::execute' % arg
breakpoint = gdb.Breakpoint(sym)
BreakOnPass()
class DumpFn(gdb.Command):
"""
A custom command to dump a gimple/rtl function to file. By default, it
dumps the current function using 0 as dump_flags, but the function and flags
can also be specified. If /f <file> are passed as the first two arguments,
the dump is written to that file. Otherwise, a temporary file is created
and opened in the text editor specified in the EDITOR environment variable.
Examples of use:
(gdb) dump-fn
(gdb) dump-fn /f foo.1.txt
(gdb) dump-fn cfun->decl
(gdb) dump-fn /f foo.1.txt cfun->decl
(gdb) dump-fn cfun->decl 0
(gdb) dump-fn cfun->decl dump_flags
"""
def __init__(self):
gdb.Command.__init__(self, 'dump-fn', gdb.COMMAND_USER)
def invoke(self, arg, from_tty):
# Parse args, check number of args
args = gdb.string_to_argv(arg)
if len(args) >= 1 and args[0] == "/f":
if len(args) == 1:
print ("Missing file argument")
return
filename = args[1]
editor_mode = False
base_arg = 2
else:
editor = os.getenv("EDITOR", "")
if editor == "":
print ("EDITOR environment variable not defined")
return
editor_mode = True
base_arg = 0
if len(args) - base_arg > 2:
print ("Too many arguments")
return
# Set func
if len(args) - base_arg >= 1:
funcname = args[base_arg]
printfuncname = "function %s" % funcname
else:
funcname = "cfun ? cfun->decl : current_function_decl"
printfuncname = "current function"
func = gdb.parse_and_eval(funcname)
if func == 0:
print ("Could not find %s" % printfuncname)
return
func = "(tree)%u" % func
# Set flags
if len(args) - base_arg >= 2:
flags = gdb.parse_and_eval(args[base_arg + 1])
else:
flags = 0
# Get tempory file, if necessary
if editor_mode:
f = tempfile.NamedTemporaryFile(delete=False, suffix=".txt")
filename = f.name
f.close()
# Open file
fp = gdb.parse_and_eval("(FILE *) fopen (\"%s\", \"w\")" % filename)
if fp == 0:
print ("Could not open file: %s" % filename)
return
# Dump function to file
_ = gdb.parse_and_eval("dump_function_to_file (%s, %s, %u)" %
(func, fp, flags))
# Close file
ret = gdb.parse_and_eval("(int) fclose (%s)" % fp)
if ret != 0:
print ("Could not close file: %s" % filename)
return
# Open file in editor, if necessary
if editor_mode:
os.system("( %s \"%s\"; rm \"%s\" ) &" %
(editor, filename, filename))
DumpFn()
class DotFn(gdb.Command):
"""
A custom command to show a gimple/rtl function control flow graph.
By default, it show the current function, but the function can also be
specified.
Examples of use:
(gdb) dot-fn
(gdb) dot-fn cfun
(gdb) dot-fn cfun 0
(gdb) dot-fn cfun dump_flags
"""
def __init__(self):
gdb.Command.__init__(self, 'dot-fn', gdb.COMMAND_USER)
def invoke(self, arg, from_tty):
# Parse args, check number of args
args = gdb.string_to_argv(arg)
if len(args) > 2:
print("Too many arguments")
return
# Set func
if len(args) >= 1:
funcname = args[0]
printfuncname = "function %s" % funcname
else:
funcname = "cfun"
printfuncname = "current function"
func = gdb.parse_and_eval(funcname)
if func == 0:
print("Could not find %s" % printfuncname)
return
func = "(struct function *)%s" % func
# Set flags
if len(args) >= 2:
flags = gdb.parse_and_eval(args[1])
else:
flags = 0
# Get temp file
f = tempfile.NamedTemporaryFile(delete=False)
filename = f.name
# Close and reopen temp file to get C FILE*
f.close()
fp = gdb.parse_and_eval("(FILE *) fopen (\"%s\", \"w\")" % filename)
if fp == 0:
print("Cannot open temp file")
return
# Write graph to temp file
_ = gdb.parse_and_eval("start_graph_dump (%s, \"<debug>\")" % fp)
_ = gdb.parse_and_eval("print_graph_cfg (%s, %s, %u)"
% (fp, func, flags))
_ = gdb.parse_and_eval("end_graph_dump (%s)" % fp)
# Close temp file
ret = gdb.parse_and_eval("(int) fclose (%s)" % fp)
if ret != 0:
print("Could not close temp file: %s" % filename)
return
# Show graph in temp file
os.system("( dot -Tx11 \"%s\"; rm \"%s\" ) &" % (filename, filename))
DotFn()
print('Successfully loaded GDB hooks for GCC')
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