gdb/testsuite/gdb.dwarf2/cpp-linkage-name.exp

# Copyright 2020-2025 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/>.

# Some compilers give anonymous structures a linkage name, and that
# linkage name doesn't demangle (within GDB calling gdb_demangle
# return NULL).  At one point this caused GDB to crash due to
# dereferencing a NULL pointer.

load_lib dwarf.exp

# This test can only be run on targets which support DWARF-2 and use gas.
require dwarf2_support

standard_testfile .c -debug.S

# Set up the DWARF for the test.
set asm_file [standard_output_file $srcfile2]
Dwarf::assemble $asm_file {
    global srcfile

    cu {} {
	DW_TAG_compile_unit {
	    DW_AT_language @DW_LANG_C_plus_plus
	    DW_AT_name     $srcfile
	    DW_AT_comp_dir /tmp

	} {
	    declare_labels a_l b_l

	    a_l: DW_TAG_base_type {
		DW_AT_byte_size 4 DW_FORM_sdata
		DW_AT_encoding  @DW_ATE_signed
		DW_AT_name      int
	    }

	    # To expose the bug that existed at one point this
	    # structure must have a linkage name, but no name, and the
	    # linkage name is something that doesn't demangle.
	    b_l: DW_TAG_structure_type {
		DW_AT_byte_size 8 DW_FORM_sdata
		DW_AT_encoding  @DW_ATE_signed
		DW_AT_linkage_name <anon>
	    } {
		member {
		    DW_AT_name x
		    DW_AT_type :$a_l
		    DW_AT_data_member_location 0 data1
		}
		member {
		    DW_AT_name y
		    DW_AT_type :$a_l
		    DW_AT_data_member_location 0 data1
		}
	    }
	    DW_TAG_subprogram {
		MACRO_AT_func {main}
		DW_AT_type :$a_l
	    }
	    DW_TAG_variable {
		DW_AT_type :$b_l
		DW_AT_external 1 flag
		DW_AT_name global_var
		DW_AT_location [subst {
		    DW_OP_addr [gdb_target_symbol global_var]
		}] SPECIAL_expr
	    }
	}
    }
}

if { [prepare_for_testing "failed to prepare" ${testfile} \
	  [list $srcfile $asm_file] {nodebug}] } {
    return -1
}

gdb_assert [runto_main] "run to main"
gdb_test "p global_var" " = {x = 0, y = 0}"