Use dwarf assembler in gdb.dwarf2/implptr-64bit.exp

This patch adds a DW_OP_implicit_value in dwarf assembler, and uses
dwarf assembler in implptr-64bit.exp.  Using dwarf assembler in
implptr-64bit.exp exposes some limitations in dwarf assembler,

 - some variables are not evaluated in the caller's context, so we
   can not pass variable to assembler, like this

       Dwarf::assemble $asm_file {

	cu {
	    version $dwarf_version
	    addr_size $addr_size
	    is_64 $is_64
	} {
	}

	and

	{DW_AT_type :$struct_label "DW_FORM_ref$ref_addr_size"}

   this limitation is fixed by adding "uplevel" and "subst".

 - dwarf assembler doesn't emit DW_FORM_ref_addr for label referencing.
   this limitation is fixed by adding a new character "%",

	{ type %$int_label }

   this means we want to emit DW_FORM_ref_addr for label referencing.

 - we can't set the form of label referencing offset in dwarf assembler.
   Nowadays, dwarf assembler guesses the form of labels, which is
   DW_FORM_ref4.  However, in implptr-64bit.exp, both DW_FORM_ref4
   and DW_FORM_ref8 is used (see REF_ADDR in implptr-64bit.S).  This
   patch adds the flexibility of setting the form of label reference.
   Both of them below are valid,

	{DW_AT_type :$struct_label}
	{DW_AT_type :$struct_label DW_FORM_ref8}

   the former form is the default DW_FORM_ref4.

I compared the .debug_info of objects without and with this patch
applied.  There is no changes except abbrev numbers.

gdb/testsuite:

2017-01-25  Andreas Arnez  <arnez@linux.vnet.ibm.com>
	    Yao Qi  <yao.qi@linaro.org>

	* gdb.dwarf2/implptr-64bit.exp: Use dwarf assembler.
	* gdb.dwarf2/implptr-64bit.S: Remove.
	* lib/dwarf.exp (Dwarf): Handle character "%".  Evaluate some
	variables in caller's context.  Add DW_OP_implicit_value.
This commit is contained in:
Yao Qi 2017-01-25 16:24:44 +00:00
parent 5ac9524116
commit f13a9a0cf7
4 changed files with 154 additions and 236 deletions

View File

@ -1,3 +1,11 @@
2017-01-25 Andreas Arnez <arnez@linux.vnet.ibm.com>
Yao Qi <yao.qi@linaro.org>
* gdb.dwarf2/implptr-64bit.exp: Use dwarf assembler.
* gdb.dwarf2/implptr-64bit.S: Remove.
* lib/dwarf.exp (Dwarf): Handle character "%". Evaluate some
variables in caller's context. Add DW_OP_implicit_value.
2017-01-25 Yao Qi <yao.qi@linaro.org>
* lib/dwarf.exp (Dwarf::_location): Handle

View File

@ -1,226 +0,0 @@
/* Copyright 2010-2017 Free Software Foundation, Inc.
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/>. */
.section .debug_info
d:
/* Length of Compilation Unit Info */
#if OFFSET_SIZE == 4
# define OFFSET .4byte
# define HEADER_LINE1
# define HEADER_LINE2(END) .4byte END - 1f
#elif OFFSET_SIZE == 8
# define OFFSET .8byte
# define HEADER_LINE1 .4byte 0xffffffff
# define HEADER_LINE2(END) .8byte END - 1f
#else
# error
#endif
#if ADDR_SIZE == 4
# define ADDR .4byte
#elif ADDR_SIZE == 8
# define ADDR .8byte
#else
# error
#endif
#if REF_ADDR_SIZE == 4
# define REF_ADDR .4byte
#elif REF_ADDR_SIZE == 8
# define REF_ADDR .8byte
#else
# error
#endif
#if TWO_CU
# define END1 .Lcu_end_1
#else
# define END1 debug_end
#endif
HEADER_LINE1
HEADER_LINE2(END1)
1:
.2byte DWARF_VERSION /* DWARF version number */
OFFSET .Ldebug_abbrev0 /* Offset Into Abbrev. Section */
.byte ADDR_SIZE /* Pointer Size (in bytes) */
.uleb128 0x1 /* (DIE (0xb) DW_TAG_compile_unit) */
.ascii "GNU C 4.4.3\0" /* DW_AT_producer */
.byte 0x1 /* DW_AT_language */
.ascii "1.c\0" /* DW_AT_name */
.Ltype_int:
.uleb128 0x7 /* DW_TAG_base_type */
.byte 0x4 /* DW_AT_byte_size */
.byte 0x5 /* DW_AT_encoding */
.ascii "int\0" /* DW_AT_name */
.Ltype_struct:
.uleb128 0x2 /* DW_TAG_structure_type */
.ascii "s\0" /* DW_AT_name */
.byte 4 /* DW_AT_byte_size */
.uleb128 0x3 /* DW_TAG_member */
.ascii "f\0" /* DW_AT_name */
.4byte .Ltype_int - d /* DW_AT_type */
.byte 0 /* DW_AT_data_member_location */
.byte 0x0 /* end of children of DW_TAG_structure_type */
.Ltype_structptr:
.uleb128 0x5 /* DW_TAG_pointer_type */
.byte ADDR_SIZE /* DW_AT_byte_size */
.4byte .Ltype_struct - d /* DW_AT_type */
.Lvar_out:
.uleb128 0x4 /* (DW_TAG_variable) */
.ascii "v\0" /* DW_AT_name */
.byte 2f - 1f /* DW_AT_location: DW_FORM_block1 */
1:
.byte 0x9e /* DW_OP_implicit_value */
.uleb128 2f - 3f
3:
.byte 1, 1, 1, 1
2:
REF_ADDR .Ltype_struct - d /* DW_AT_type */
#if TWO_CU
.byte 0x0 /* end of children of CU */
.Lcu_end_1:
HEADER_LINE1
HEADER_LINE2 (debug_end)
1:
.2byte DWARF_VERSION /* DWARF version number */
OFFSET .Ldebug_abbrev0 /* Offset Into Abbrev. Section */
.byte ADDR_SIZE /* Pointer Size (in bytes) */
.uleb128 0x1 /* (DIE (0xb) DW_TAG_compile_unit) */
.ascii "GNU C 4.4.3\0" /* DW_AT_producer */
.byte 0x1 /* DW_AT_language */
.ascii "1.c\0" /* DW_AT_name */
#endif
.uleb128 6 /* Abbrev: DW_TAG_subprogram */
.ascii "main\0" /* DW_AT_name */
ADDR main /* DW_AT_low_pc */
ADDR main + 0x100 /* DW_AT_high_pc */
REF_ADDR .Ltype_int - d /* DW_AT_type */
.byte 1 /* DW_AT_external */
.uleb128 0x4 /* (DW_TAG_variable) */
.ascii "p\0" /* DW_AT_name */
.byte 2f - 1f /* DW_AT_location: DW_FORM_block1 */
1:
.byte 0xf2 /* DW_OP_GNU_implicit_pointer */
REF_ADDR .Lvar_out - d /* referenced DIE */
.sleb128 0 /* offset */
2:
REF_ADDR .Ltype_structptr - d /* DW_AT_type */
.byte 0x0 /* end of children of main */
.byte 0x0 /* end of children of CU */
debug_end:
.section .debug_abbrev
.Ldebug_abbrev0:
.uleb128 0x1 /* (abbrev code) */
.uleb128 0x11 /* (TAG: DW_TAG_compile_unit) */
.byte 0x1 /* DW_children_yes */
.uleb128 0x25 /* (DW_AT_producer) */
.uleb128 0x8 /* (DW_FORM_string) */
.uleb128 0x13 /* (DW_AT_language) */
.uleb128 0xb /* (DW_FORM_data1) */
.uleb128 0x3 /* (DW_AT_name) */
.uleb128 0x8 /* (DW_FORM_string) */
.byte 0x0
.byte 0x0
.uleb128 0x2 /* (abbrev code) */
.uleb128 0x13 /* (TAG: DW_TAG_structure_type) */
.byte 0x1 /* DW_children_yes */
.uleb128 0x3 /* (DW_AT_name) */
.uleb128 0x8 /* (DW_FORM_string) */
.uleb128 0xb /* (DW_AT_byte_size) */
.uleb128 0xb /* (DW_FORM_data1) */
.byte 0
.byte 0
.uleb128 0x3 /* (abbrev code) */
.uleb128 0xd /* (TAG: DW_TAG_member) */
.byte 0 /* DW_children_no */
.uleb128 0x3 /* (DW_AT_name) */
.uleb128 0x8 /* (DW_FORM_string) */
.uleb128 0x49 /* (DW_AT_type) */
.uleb128 0x13 /* (DW_FORM_ref4) */
.uleb128 0x38 /* (DW_AT_data_member_location) */
.uleb128 0xb /* (DW_FORM_data1) */
.byte 0
.byte 0
.uleb128 0x4 /* (abbrev code) */
.uleb128 0x34 /* (TAG: DW_TAG_variable) */
.byte 0x0 /* DW_children_yes */
.uleb128 0x3 /* (DW_AT_name) */
.uleb128 0x8 /* (DW_FORM_string) */
.uleb128 0x02 /* (DW_AT_location) */
.uleb128 0xa /* (DW_FORM_block1) */
.uleb128 0x49 /* (DW_AT_type) */
.uleb128 0x10 /* (DW_FORM_ref_addr) */
.byte 0x0
.byte 0x0
.uleb128 0x5 /* (abbrev code) */
.uleb128 0xf /* (TAG: DW_TAG_pointer_type) */
.byte 0x0 /* DW_children_no */
.uleb128 0xb /* (DW_AT_byte_size) */
.uleb128 0xb /* (DW_FORM_data1) */
.uleb128 0x49 /* (DW_AT_type) */
.uleb128 0x13 /* (DW_FORM_ref4) */
.byte 0x0
.byte 0x0
.uleb128 6 /* Abbrev code */
.uleb128 0x2e /* DW_TAG_subprogram */
.byte 1 /* has_children */
.uleb128 0x3 /* DW_AT_name */
.uleb128 0x8 /* DW_FORM_string */
.uleb128 0x11 /* DW_AT_low_pc */
.uleb128 0x1 /* DW_FORM_addr */
.uleb128 0x12 /* DW_AT_high_pc */
.uleb128 0x1 /* DW_FORM_addr */
.uleb128 0x49 /* DW_AT_type */
.uleb128 0x10 /* DW_FORM_ref_addr */
.uleb128 0x3f /* DW_AT_external */
.uleb128 0xc /* DW_FORM_flag */
.byte 0x0 /* Terminator */
.byte 0x0 /* Terminator */
.uleb128 0x7 /* (abbrev code) */
.uleb128 0x24 /* (TAG: DW_TAG_base_type) */
.byte 0 /* DW_children_no */
.uleb128 0xb /* (DW_AT_byte_size) */
.uleb128 0xb /* (DW_FORM_data1) */
.uleb128 0x3e /* (DW_AT_encoding) */
.uleb128 0xb /* (DW_FORM_data1) */
.uleb128 0x3 /* (DW_AT_name) */
.uleb128 0x8 /* (DW_FORM_string) */
.byte 0
.byte 0
.byte 0x0

View File

@ -19,21 +19,121 @@ if {![dwarf2_support]} {
return 0
}
standard_testfile .S
set mainfile main.c
standard_testfile main.c
proc test { dwarf_version offset_size addr_size ref_addr_size two_cu } {
global testfile srcfile mainfile
global testfile srcfile
set name "d${dwarf_version}o${offset_size}a${addr_size}r${ref_addr_size}t${two_cu}"
# Make some DWARF for the test.
set asm_file [standard_output_file ${testfile}-${name}.S]
Dwarf::assemble $asm_file {
upvar dwarf_version dwarf_version
upvar addr_size addr_size
upvar offset_size offset_size
upvar ref_addr_size ref_addr_size
upvar two_cu two_cu
set is_64 [expr { $offset_size == 4 ? 0 : 1 }]
cu {
version $dwarf_version
addr_size $addr_size
is_64 $is_64
} {
compile_unit {
{ producer "GNU C 4.4.3" }
{ language @DW_LANG_C89 }
{ name 1.c }
} {
declare_labels struct_label variable_label int_label pointer_label
int_label: base_type {
{ byte_size 4 DW_FORM_sdata }
{ DW_AT_encoding @DW_ATE_signed }
{ name int }
}
struct_label: structure_type {
{ name s }
{ byte_size 4 sdata }
} {
member {
{ name f }
{ type :$int_label }
{ data_member_location 0 data1 }
}
}
pointer_label: pointer_type {
{ byte_size $Dwarf::_cu_addr_size sdata }
{ type :$struct_label }
}
variable_label: DW_TAG_variable {
{ name v }
{ location {
DW_OP_implicit_value 0x1 0x1 0x1 0x1
} SPECIAL_expr}
{ type :$struct_label "DW_FORM_ref$ref_addr_size" }
}
if { !$two_cu } {
subprogram {
{ name main }
{ low_pc main addr }
{ high_pc "main+0x100" addr }
{ type %$int_label }
{ external 1 flag }
} {
DW_TAG_variable {
{ name p }
{ location {
GNU_implicit_pointer $variable_label 0
} SPECIAL_expr }
{ type :$pointer_label "DW_FORM_ref$ref_addr_size" }
}
}
}
}
}
if { $two_cu } {
cu {
version $dwarf_version
addr_size $addr_size
is_64 $is_64
} {
compile_unit {
{ producer "GNU C 4.4.3" }
{ language @DW_LANG_C89 }
{ name 1.c }
} {
subprogram {
{ name main }
{ low_pc main addr }
{ high_pc "main+0x100" addr }
{ type %$int_label }
{ external 1 flag }
} {
DW_TAG_variable {
{ name p }
{ location {
GNU_implicit_pointer $variable_label 0
} SPECIAL_expr }
{ type %$pointer_label }
}
}
}
}
}
}
# 32-bit targets do not support any of the testcases; keep quiet there.
set opts {quiet}
foreach n { dwarf_version offset_size addr_size ref_addr_size two_cu } {
lappend opts "additional_flags=-D[string toupper $n]=[expr "\$$n"]"
}
set name "d${dwarf_version}o${offset_size}a${addr_size}r${ref_addr_size}t${two_cu}"
set executable ${testfile}-${name}
if [prepare_for_testing "failed to prepare" $executable "${srcfile} ${mainfile}" $opts] {
if [prepare_for_testing "failed to prepare" $executable "${asm_file} ${srcfile}" $opts] {
return -1
}

View File

@ -229,6 +229,8 @@ proc function_range { func src } {
# * If VALUE starts with the ":" character, then it is a label
# reference. The rest of VALUE is taken to be the name of a label,
# and DW_FORM_ref4 is used. See 'new_label' and 'define_label'.
# * If VALUE starts with the "%" character, then it is a label
# reference too, but DW_FORM_ref_addr is used.
# * Otherwise, VALUE is taken to be a string and DW_FORM_string is
# used. In order to prevent bugs where a numeric value is given but
# no form is specified, it is an error if the value looks like a number
@ -554,6 +556,15 @@ namespace eval Dwarf {
return DW_FORM_ref4
}
% {
# Label reference, an offset from .debug_info. Assuming
# .Lcu1_begin is on .debug_info.
set cu1_label [_compute_label "cu1_begin"]
set new_value "[string range $value 1 end] - $cu1_label"
return DW_FORM_ref_addr
}
default {
return DW_FORM_string
}
@ -649,7 +660,12 @@ namespace eval Dwarf {
_handle_macro_at_range $attr_value
} else {
if {[llength $attr] > 2} {
set attr_form [lindex $attr end]
set attr_form [uplevel 2 [list subst [lindex $attr end]]]
if { [string index $attr_value 0] == ":" } {
# It is a label, get its value.
_guess_form $attr_value attr_value
}
} else {
# If the value looks like an integer, a form is required.
if [string is integer $attr_value] {
@ -907,6 +923,25 @@ namespace eval Dwarf {
_op .2byte [lindex $line 1]
}
DW_OP_implicit_value {
set l1 [new_label "value_start"]
set l2 [new_label "value_end"]
_op .uleb128 "$l2 - $l1"
define_label $l1
foreach value [lrange $line 1 end] {
switch -regexp -- $value {
{^0x[[:xdigit:]]{1,2}$} {_op .byte $value}
{^0x[[:xdigit:]]{4}$} {_op .2byte $value}
{^0x[[:xdigit:]]{8}$} {_op .4byte $value}
{^0x[[:xdigit:]]{16}$} {_op .8byte $value}
default {
error "bad value '$value' in DW_OP_implicit_value"
}
}
}
define_label $l2
}
DW_OP_GNU_implicit_pointer {
if {[llength $line] != 3} {
error "usage: DW_OP_GNU_implicit_pointer LABEL OFFSET"
@ -976,6 +1011,7 @@ namespace eval Dwarf {
set _abbrev_section ".debug_abbrev"
foreach { name value } $options {
set value [uplevel 1 "subst \"$value\""]
switch -exact -- $name {
is_64 { set is_64 $value }
version { set _cu_version $value }