gdb/testsuite: Add is-stmt support to the DWARF compiler

This commit adds the ability to set and toggle the DWARF line table
is-stmt flag.

A DWARF line table can now be created with the attribute
'default_is_stmt' like this:

  lines {version 2 default_is_stmt 0} label {
    ...
  }

If 'default_is_stmt' is not specified then the current default is 1,
which matches the existing behaviour.

Inside the DWARF line table program you can now make use of
{DW_LNS_negate_stmt} to toggle the is-stmt flag, for example this
meaningless program:

  lines {version 2 default_is_stmt 0} label {
    include_dir "some_directory"
    file_name "some_filename" 1

    program {
      {DW_LNS_negate_stmt}
      {DW_LNE_end_sequence}
    }
  }

This new functionality will be used in a later commit.

gdb/testsuite/ChangeLog:

	* lib/dwarf.exp (Dwarf::lines) Add support for modifying the
	is-stmt flag in the line table.

Change-Id: Ia3f61d523826382dd2333f65b9aae368ad29c4a5
This commit is contained in:
Andrew Burgess 2020-02-04 17:50:40 +00:00
parent a6a1f5e050
commit cecf854779
2 changed files with 12 additions and 1 deletions

View File

@ -1,3 +1,8 @@
2020-03-10 Andrew Burgess <andrew.burgess@embecosm.com>
* lib/dwarf.exp (Dwarf::lines) Add support for modifying the
is-stmt flag in the line table.
2020-03-09 Tom de Vries <tdevries@suse.de>
* lib/gdb.exp (cached_file): Create cache dir.

View File

@ -1311,12 +1311,14 @@ namespace eval Dwarf {
set _unit_addr_size default
set _line_saw_program 0
set _line_saw_file 0
set _default_is_stmt 1
foreach { name value } $options {
switch -exact -- $name {
is_64 { set is_64 $value }
version { set _unit_version $value }
addr_size { set _unit_addr_size $value }
default_is_stmt { set _default_is_stmt $value }
default { error "unknown option $name" }
}
}
@ -1363,7 +1365,7 @@ namespace eval Dwarf {
define_label $header_len_label
_op .byte 1 "minimum_instruction_length"
_op .byte 1 "default_is_stmt"
_op .byte $_default_is_stmt "default_is_stmt"
_op .byte 1 "line_base"
_op .byte 1 "line_range"
_op .byte 10 "opcode_base"
@ -1438,6 +1440,10 @@ namespace eval Dwarf {
_op .byte 1
}
proc DW_LNS_negate_stmt {} {
_op .byte 6
}
proc DW_LNS_advance_pc {offset} {
_op .byte 2
_op .uleb128 ${offset}