# Python hooks for gdb for debugging GCC
-# Copyright (C) 2013 Free Software Foundation, Inc.
+# Copyright (C) 2013-2015 Free Software Foundation, Inc.
# Contributed by David Malcolm <dmalcolm@redhat.com>
1594 execute_pass_list (g->get_passes ()->all_passes);
(gdb) p node
$1 = <cgraph_node* 0x7ffff0312720 "foo">
+
+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 gdb
import gdb.printing
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
self.gdbval = gdbval
def is_nonnull(self):
- return long(self.gdbval)
+ return intptr(self.gdbval)
def TREE_CODE(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 long(self.gdbval) == 0:
+ if intptr(self.gdbval) == 0:
return '<tree 0x0>'
val_TREE_CODE = self.node.TREE_CODE()
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[long(val_TREE_CODE)]
- #print val_code_name.string()
+ val_code_name = val_tree_code_name[intptr(val_TREE_CODE)]
+ #print(val_code_name.string())
- result = '<%s 0x%x' % (val_code_name.string(), long(self.gdbval))
- if long(val_tclass) == tcc_declaration:
+ result = '<%s 0x%x' % (val_code_name.string(), 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 long(val_tclass) == tcc_type:
+ 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:
self.gdbval = gdbval
def to_string (self):
- result = '<cgraph_node* 0x%x' % long(self.gdbval)
- if long(self.gdbval):
+ result = '<cgraph_node* 0x%x' % 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));
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:
self.gdbval = gdbval
def to_string (self):
- if long(self.gdbval) == 0:
+ 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[long(val_gimple_code)]
+ val_code_name = val_gimple_code_name[intptr(val_gimple_code)]
result = '<%s 0x%x' % (val_code_name.string(),
- long(self.gdbval))
+ intptr(self.gdbval))
result += '>'
return result
self.gdbval = gdbval
def to_string (self):
- result = '<basic_block 0x%x' % long(self.gdbval)
- if long(self.gdbval):
- result += ' (%s)' % bb_index_to_str(long(self.gdbval['index']))
+ 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
self.gdbval = gdbval
def to_string (self):
- result = '<edge 0x%x' % long(self.gdbval)
- if long(self.gdbval):
- src = bb_index_to_str(long(self.gdbval['src']['index']))
- dest = bb_index_to_str(long(self.gdbval['dest']['index']))
+ 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
def GET_RTX_LENGTH(code):
val_rtx_length = gdb.parse_and_eval('rtx_length')
- return long(val_rtx_length[code])
+ return intptr(val_rtx_length[code])
def GET_RTX_NAME(code):
val_rtx_name = gdb.parse_and_eval('rtx_name')
"""
# We use print_inline_rtx to avoid a trailing newline
gdb.execute('call print_inline_rtx (stderr, (const_rtx) %s, 0)'
- % long(self.gdbval))
+ % intptr(self.gdbval))
return ''
# or by hand; based on gcc/print-rtl.c:print_rtx
result = ('<rtx_def 0x%x'
- % (long(self.gdbval)))
+ % (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]
+ print(format_[i])
result += ')>'
return result
self.gdbval = gdbval
def to_string (self):
- result = '<opt_pass* 0x%x' % long(self.gdbval)
- if long(self.gdbval):
+ result = '<opt_pass* 0x%x' % intptr(self.gdbval)
+ if intptr(self.gdbval):
result += (' "%s"(%i)'
% (self.gdbval['name'].string(),
- long(self.gdbval['static_pass_number'])))
+ 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])
+
+######################################################################
+
# TODO:
-# * vec
# * hashtab
# * location_t
'tree', TreePrinter)
pp.add_printer_for_types(['cgraph_node *'],
'cgraph_node', CGraphNodePrinter)
- pp.add_printer_for_types(['gimple', 'gimple_statement_base *'],
+ pp.add_printer_for_types(['dw_die_ref'],
+ 'dw_die_ref', DWDieRefPrinter)
+ pp.add_printer_for_types(['gimple', 'gimple_statement_base *',
+
+ # 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 *'],
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)
+
return pp
gdb.printing.register_pretty_printer(
gdb.current_objfile(),
build_pretty_printer())
+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()
+
print('Successfully loaded GDB hooks for GCC')
projects / gcc.git / blobdiff