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Handle DW_AT_ranges when reading partial symtabs
add_partial_subprogram does not handle DW_AT_ranges, while the full symtab reader does. This can lead to discrepancies where a function is not put into a partial symtab, and so is not available to "break" and the like -- but is available if the full symtab has somehow been read. This patch fixes the bug by arranging to read DW_AT_ranges when reading partial DIEs. This is PR symtab/23331. The new test case is derived from dw2-ranges-func.exp, which is why I kept the copyright dates. gdb/ChangeLog 2019-04-01 Tom Tromey <tromey@adacore.com> PR symtab/23331: * dwarf2read.c (partial_die_info::read): Handle DW_AT_ranges. gdb/testsuite/ChangeLog 2019-04-01 Tom Tromey <tromey@adacore.com> PR symtab/23331: * gdb.dwarf2/dw2-ranges-main.c: New file. * gdb.dwarf2/dw2-ranges-psym.c: New file. * gdb.dwarf2/dw2-ranges-psym.exp: New file.
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‎gdb/ChangeLog‎

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2019-04-01 Tom Tromey <tromey@adacore.com>
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PR symtab/23331:
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* dwarf2read.c (partial_die_info::read): Handle DW_AT_ranges.
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2019-04-01 Sergio Durigan Junior <sergiodj@redhat.com>
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Pedro Alves <palves@redhat.com>
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‎gdb/dwarf2read.c‎

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@@ -18751,6 +18751,25 @@ partial_die_info::read (const struct die_reader_specs *reader,
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main_subprogram = DW_UNSND (&attr);
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break;
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case DW_AT_ranges:
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{
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/* It would be nice to reuse dwarf2_get_pc_bounds here,
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but that requires a full DIE, so instead we just
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reimplement it. */
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int need_ranges_base = tag != DW_TAG_compile_unit;
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unsigned int ranges_offset = (DW_UNSND (&attr)
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+ (need_ranges_base
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? cu->ranges_base
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: 0));
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/* Value of the DW_AT_ranges attribute is the offset in the
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.debug_ranges section. */
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if (dwarf2_ranges_read (ranges_offset, &lowpc, &highpc, cu,
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nullptr))
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has_pc_info = 1;
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}
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break;
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default:
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break;
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}

‎gdb/testsuite/ChangeLog‎

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2019-04-01 Tom Tromey <tromey@adacore.com>
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PR symtab/23331:
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* gdb.dwarf2/dw2-ranges-main.c: New file.
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* gdb.dwarf2/dw2-ranges-psym.c: New file.
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* gdb.dwarf2/dw2-ranges-psym.exp: New file.
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2019-03-30 Simon Marchi <simark@simark.ca>
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* gdb.base/default.exp: Add values for $_gdb_major and

‎gdb/testsuite/gdb.dwarf2/dw2-ranges-main.c‎

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/* Copyright 2019 Free Software Foundation, Inc.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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int main ()
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{
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return 0;
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}

‎gdb/testsuite/gdb.dwarf2/dw2-ranges-psym.c‎

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/* Copyright 2018-2019 Free Software Foundation, Inc.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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volatile int e = 0;
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void
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baz (void)
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{
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asm ("baz_label: .globl baz_label");
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} /* baz end */
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void
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foo_low (void)
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{ /* foo_low prologue */
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asm ("foo_low_label: .globl foo_low_label");
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baz (); /* foo_low baz call */
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asm ("foo_low_label2: .globl foo_low_label2");
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} /* foo_low end */
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void
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bar (void)
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{
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asm ("bar_label: .globl bar_label");
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} /* bar end */
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void
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foo (void)
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{ /* foo prologue */
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asm ("foo_label: .globl foo_label");
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bar (); /* foo bar call */
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asm ("foo_label2: .globl foo_label2");
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if (e) foo_low (); /* foo foo_low call */
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asm ("foo_label3: .globl foo_label3");
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} /* foo end */

‎gdb/testsuite/gdb.dwarf2/dw2-ranges-psym.exp‎

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# Copyright 2018-2019 Free Software Foundation, Inc.
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 3 of the License, or
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# (at your option) any later version.
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#
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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#
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# You should have received a copy of the GNU General Public License
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# along with this program. If not, see <http://www.gnu.org/licenses/>.
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load_lib dwarf.exp
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# Test that psymbols are made when DW_AT_ranges is used.
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# This test can only be run on targets which support DWARF-2 and use gas.
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if {![dwarf2_support]} {
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unsupported "dwarf2 support required for this test"
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return 0
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}
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if [get_compiler_info] {
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return -1
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}
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if !$gcc_compiled {
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unsupported "gcc required for this test"
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return 0
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}
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standard_testfile dw2-ranges-main.c dw2-ranges-psym.c dw2-ranges-psym-dw.S
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# We need to know the size of integer and address types in order to
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# write some of the debugging info we'd like to generate.
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#
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# For that, we ask GDB by debugging our test program. Any program
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# would do, but since we already have it specifically for this
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# testcase, might as well use that.
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if { [prepare_for_testing "failed to prepare" ${testfile} \
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[list ${srcfile} ${srcfile2}]] } {
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return -1
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}
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set asm_file [standard_output_file $srcfile3]
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Dwarf::assemble $asm_file {
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global srcdir subdir srcfile srcfile2
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declare_labels integer_label volatile_label func_ranges_label cu_ranges_label
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set int_size [get_sizeof "int" 4]
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# Find start address and length for our functions.
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set sources [list ${srcdir}/${subdir}/$srcfile ${srcdir}/${subdir}/$srcfile2]
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lassign [function_range foo $sources] \
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foo_start foo_len
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set foo_end "$foo_start + $foo_len"
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lassign [function_range foo_low $sources] \
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foo_low_start foo_low_len
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set foo_low_end "$foo_low_start + $foo_low_len"
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lassign [function_range bar $sources] \
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bar_start bar_len
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set bar_end "$bar_start + $bar_len"
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lassign [function_range baz $sources] \
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baz_start baz_len
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set baz_end "$baz_start + $baz_len"
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cu {} {
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compile_unit {
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{language @DW_LANG_C}
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{name dw-ranges-psym.c}
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{low_pc 0 addr}
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{ranges ${cu_ranges_label} DW_FORM_sec_offset}
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} {
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integer_label: DW_TAG_base_type {
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{DW_AT_byte_size $int_size DW_FORM_sdata}
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{DW_AT_encoding @DW_ATE_signed}
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{DW_AT_name integer}
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}
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volatile_label: DW_TAG_volatile_type {
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{type :$integer_label}
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}
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subprogram {
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{external 1 flag}
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{name someothername}
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{ranges ${func_ranges_label} DW_FORM_sec_offset}
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}
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subprogram {
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{external 1 flag}
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{name bar}
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{low_pc $bar_start addr}
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{high_pc $bar_len DW_FORM_data4}
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}
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subprogram {
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{external 1 flag}
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{name baz}
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{low_pc $baz_start addr}
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{high_pc $baz_len DW_FORM_data4}
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}
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}
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}
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# Generate ranges data.
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ranges {is_64 [is_64_target]} {
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func_ranges_label: sequence {
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{range {$foo_start } $foo_end}
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{range {$foo_low_start} $foo_low_end}
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}
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cu_ranges_label: sequence {
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{range {$foo_start } $foo_end}
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{range {$foo_low_start} $foo_low_end}
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{range {$bar_start} $bar_end}
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{range {$baz_start} $baz_end}
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}
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}
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}
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if { [prepare_for_testing "failed to prepare" ${testfile} \
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[list $srcfile $srcfile2 $asm_file] {nodebug}] } {
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return -1
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}
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if ![runto_main] {
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return -1
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}
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# "someothername" should be put into the partial symbol table, but
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# there was a bug causing functions using DW_AT_ranges not to be.
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# Note we use a name that is very different from the linkage name, in
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# order to not set the breakpoint via minsyms.
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gdb_test "break someothername" \
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"Breakpoint.*at.*" \
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"break someothername"

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