Omit artificial symbols from DAP variables response

While testing DAP, we found a situation where a compiler-generated
variable caused the "variables" request to fail -- the variable in
question being an apparent 67-megabyte string.

It seems to me that artificial variables like this aren't interesting
to DAP users, and the gdb CLI omits these as well.

This patch changes DAP to omit these variables, adding a new
gdb.Symbol.is_artificial attribute to make this possible.

1 files changed, 62 insertions, 0 deletions

diff --git a/gdb/testsuite/gdb.python/py-sym-artificial.exp b/gdb/testsuite/gdb.python/py-sym-artificial.exp
new file mode 100644
index 0000000..3ae516c
--- /dev/null
+++ b/gdb/testsuite/gdb.python/py-sym-artificial.exp
@@ -0,0 +1,62 @@
+# Copyright (C) 2024 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 gdb.Symbol.artificial.
+
+load_lib dwarf.exp
+load_lib gdb-python.exp
+
+require dwarf2_support allow_python_tests
+
+# Just use a no-op main.
+standard_testfile py-arch.c -dw.S
+
+set asm_file [standard_output_file ${srcfile2}]
+Dwarf::assemble $asm_file {
+    cu {} {
+	compile_unit {
+	    {language @DW_LANG_C}
+	    {name py-sym-artificial.c}
+	} {
+	    declare_labels signed
+
+	    signed: DW_TAG_base_type {
+		{DW_AT_byte_size 1 DW_FORM_sdata}
+		{DW_AT_encoding  @DW_ATE_signed}
+		{DW_AT_name      bool}
+	    }
+
+	    DW_TAG_variable {
+		{name the_variable}
+		{DW_AT_type :$signed}
+		{artificial 1 DW_FORM_flag_present}
+	    }
+	}
+    }
+}
+
+if {[prepare_for_testing "failed to prepare" ${testfile} \
+	 [list $srcfile $asm_file] {nodebug}]} {
+    return -1
+}
+
+if {![runto_main]} {
+    return -1
+}
+
+gdb_py_test_silent_cmd "python v = gdb.lookup_symbol('the_variable')" \
+    "get variable" 1
+gdb_test "python print(v\[0\].is_artificial)" True \
+    "variable is artificial"