[PATCH 1/9] Add test for modifiable DWARF locations

Andreas Arnez
2017-04-07T17:39:44Z

This adds a test for read/write access to variables with various types of
DWARF locations. It uses register- and memory locations and composite
locations with register- and memory pieces.

Since the new test calls gdb_test_no_output with commands that contain
braces, it is necessary for string_to_regexp to quote braces as well.
This was not done before.

gdb/testsuite/ChangeLog:

* gdb.dwarf2/var-access.c: New file.
* gdb.dwarf2/var-access.exp: New test.
* lib/gdb-utils.exp (string_to_regexp): Quote braces as well.
---
gdb/testsuite/gdb.dwarf2/var-access.c | 25 +++++
gdb/testsuite/gdb.dwarf2/var-access.exp | 193 ++++++++++++++++++++++++++++++++
gdb/testsuite/lib/gdb-utils.exp | 2 +-
3 files changed, 219 insertions(+), 1 deletion(-)
create mode 100644 gdb/testsuite/gdb.dwarf2/var-access.c
create mode 100644 gdb/testsuite/gdb.dwarf2/var-access.exp

diff --git a/gdb/testsuite/gdb.dwarf2/var-access.c b/gdb/testsuite/gdb.dwarf2/var-access.c
new file mode 100644
index 0000000..108be82
--- /dev/null
+++ b/gdb/testsuite/gdb.dwarf2/var-access.c
@@ -0,0 +1,25 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 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/>. */
+
+char buf[] = {0, 1, 2, 3, 4, 5, 6, 7};
+
+int
+main (void)
+{
+ asm volatile ("main_label: .globl main_label");
+ return 0;
+}
diff --git a/gdb/testsuite/gdb.dwarf2/var-access.exp b/gdb/testsuite/gdb.dwarf2/var-access.exp
new file mode 100644
index 0000000..ee93b93
--- /dev/null
+++ b/gdb/testsuite/gdb.dwarf2/var-access.exp
@@ -0,0 +1,193 @@
+# Copyright 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/>.
+
+# Test reading/writing variables with non-trivial DWARF locations.
+
+load_lib dwarf.exp
+
+# This test can only be run on targets which support DWARF-2 and use gas.
+if {![dwarf2_support]} {
+ return 0
+}
+
+# Choose suitable integer registers for the test.
+
+set dwarf_regnum {0 1}
+
+if { [istarget "aarch64*-*-*"] } {
+ set regname {x0 x1}
+} elseif { [istarget "arm*-*-*"]
+ || [istarget "s390*-*-*" ]
+ || [istarget "powerpc*-*-*"]
+ || [istarget "rs6000*-*-aix*"] } {
+ set regname {r0 r1}
+} elseif { [istarget "i?86-*-*"] } {
+ set regname {eax edx}
+} elseif { [istarget "x86_64-*-*"] } {
+ set regname {rax rdx}
+} else {
+ verbose "Skipping tests for accessing DWARF-described variables."
+ return
+}
+
+standard_testfile .c ${gdb_test_file_name}-dw.S
+
+# Make some DWARF for the test.
+
+set asm_file [standard_output_file $srcfile2]
+Dwarf::assemble $asm_file {
+ global srcdir subdir srcfile
+ global dwarf_regnum regname
+
+ set main_func \
+ [function_range main [list ${srcdir}/${subdir}/$srcfile]]
+ set buf_var [gdb_target_symbol buf]
+
+ cu {} {
+ DW_TAG_compile_unit {
+ {DW_AT_name var-pieces-dw.c}
+ {DW_AT_comp_dir /tmp}
+ } {
+ declare_labels char_type_label
+ declare_labels int_type_label short_type_label
+ declare_labels array_a8_label struct_s_label
+
+ char_type_label: base_type {
+ {name "char"}
+ {encoding @DW_ATE_unsigned_char}
+ {byte_size 1 DW_FORM_sdata}
+ }
+
+ int_type_label: base_type {
+ {name "int"}
+ {encoding @DW_ATE_signed}
+ {byte_size 4 DW_FORM_sdata}
+ }
+
+ array_a8_label: array_type {
+ {type :$char_type_label}
+ } {
+ subrange_type {
+ {type :$int_type_label}
+ {upper_bound 7 DW_FORM_udata}
+ }
+ }
+
+ struct_s_label: structure_type {
+ {name "s"}
+ {byte_size 4 DW_FORM_sdata}
+ } {
+ member {
+ {name "a"}
+ {type :$char_type_label}
+ {data_member_location 0 DW_FORM_udata}
+ }
+ member {
+ {name "b"}
+ {type :$char_type_label}
+ {data_member_location 1 DW_FORM_udata}
+ }
+ member {
+ {name "c"}
+ {type :$char_type_label}
+ {data_member_location 2 DW_FORM_udata}
+ }
+ member {
+ {name "d"}
+ {type :$char_type_label}
+ {data_member_location 3 DW_FORM_udata}
+ }
+ }
+
+ DW_TAG_subprogram {
+ {name "main"}
+ {DW_AT_external 1 flag}
+ {low_pc [lindex $main_func 0] DW_FORM_addr}
+ {high_pc [lindex $main_func 1] DW_FORM_udata}
+ } {
+ # Simple memory location.
+ DW_TAG_variable {
+ {name "a"}
+ {type :$array_a8_label}
+ {location {
+ addr $buf_var
+ } SPECIAL_expr}
+ }
+ # Memory pieces.
+ DW_TAG_variable {
+ {name "s1"}
+ {type :$struct_s_label}
+ {location {
+ addr $buf_var
+ plus_uconst 2
+ piece 2
+ addr $buf_var
+ piece 2
+ } SPECIAL_expr}
+ }
+ # Register- and memory pieces.
+ DW_TAG_variable {
+ {name "s2"}
+ {type :$struct_s_label}
+ {location {
+ regx [lindex $dwarf_regnum 0]
+ piece 1
+ addr "$buf_var + 4"
+ piece 1
+ regx [lindex $dwarf_regnum 1]
+ piece 1
+ addr "$buf_var + 5"
+ piece 1
+ } SPECIAL_expr}
+ }
+ }
+ }
+ }
+}
+
+if { [prepare_for_testing ${testfile}.exp ${testfile} \
+ [list $srcfile $asm_file] {nodebug}] } {
+ return -1
+}
+
+if ![runto_main] {
+ return -1
+}
+
+# Byte-aligned memory pieces.
+gdb_test "print/d s1" " = \\{a = 2, b = 3, c = 0, d = 1\\}" \
+ "s1 == re-ordered buf"
+gdb_test_no_output "set var s1.a = 63"
+gdb_test "print/d s1" " = \\{a = 63, b = 3, c = 0, d = 1\\}" \
+ "verify s1.a"
+gdb_test "print/d a" " = \\{0, 1, 63, 3, 4, 5, 6, 7\\}" \
+ "verify s1.a through a"
+
+# Byte-aligned register- and memory pieces.
+gdb_test_no_output "set var \$[lindex $regname 0] = 81" \
+ "init reg for s2.a"
+gdb_test_no_output "set var \$[lindex $regname 1] = 28" \
+ "init reg for s2.c"
+gdb_test "print/d s2" " = \\{a = 81, b = 4, c = 28, d = 5\\}" \
+ "initialized s2 from mem and regs"
+gdb_test_no_output "set var s2.c += s2.a + s2.b - s2.d"
+gdb_test "print/d s2" " = \\{a = 81, b = 4, c = 108, d = 5\\}" \
+ "verify s2.c"
+gdb_test "print/d \$[lindex $regname 1]" " = 108" \
+ "verify s2.c through reg"
+gdb_test_no_output "set var s2 = {191, 73, 231, 123}" \
+ "re-initialize s2"
+gdb_test "print/d s2" " = \\{a = 191, b = 73, c = 231, d = 123\\}" \
+ "verify re-initialized s2"
diff --git a/gdb/testsuite/lib/gdb-utils.exp b/gdb/testsuite/lib/gdb-utils.exp
index ff1b24a..37abb14 100644
--- a/gdb/testsuite/lib/gdb-utils.exp
+++ b/gdb/testsuite/lib/gdb-utils.exp
@@ -34,6 +34,6 @@ proc gdb_init_commands {} {

proc string_to_regexp {str} {
set result $str
- regsub -all {[]*+.|()^$\[\\]} $str {\\&} result
+ regsub -all {[]*+.|(){}^$\[\\]} $str {\\&} result
return $result
}
--
2.3.0