gdb/testsuite/gdb.dwarf2/implptrpiece.exp

# Copyright 2013-2026 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/>.

load_lib dwarf.exp

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

require allow_cplus_tests

standard_testfile main.c -dw.S

# Make some DWARF for the test.
set asm_file [standard_output_file $srcfile2]

Dwarf::assemble $asm_file {
    # Using a funny address size here and in the pointer type lets us
    # also check for a sign-extension bug in the
    # DW_OP_GNU_implicit_pointer code.
    cu { addr_size 2 } {
	compile_unit {} {
	    declare_labels struct_label short_type_label
	    declare_labels char_type_label ptr_label
	    declare_labels var_label

	    struct_label: structure_type {
		DW_AT_name S
		DW_AT_byte_size 4 DW_FORM_sdata
	    } {
		member {
		    DW_AT_name a
		    DW_AT_type :$short_type_label
		    DW_AT_data_member_location 0 DW_FORM_sdata
		}
		member {
		    DW_AT_name b
		    DW_AT_type :$char_type_label
		    DW_AT_data_member_location 2 DW_FORM_sdata
		}
		member {
		    DW_AT_name c
		    DW_AT_type :$char_type_label
		    DW_AT_data_member_location 3 DW_FORM_sdata
		}
	    }

	    short_type_label: base_type {
		DW_AT_name "short int"
		DW_AT_encoding @DW_ATE_signed
		DW_AT_byte_size 2 DW_FORM_sdata
	    }

	    char_type_label: base_type {
		DW_AT_name "signed char"
		DW_AT_encoding @DW_ATE_signed
		DW_AT_byte_size 1 DW_FORM_sdata
	    }

	    # See comment above to understand the pointer size.
	    ptr_label: pointer_type {
		DW_AT_byte_size 2 DW_FORM_sdata
		DW_AT_type :$char_type_label
	    }

	    var_label: DW_TAG_variable {
		DW_AT_name s
		DW_AT_type :$struct_label
		DW_AT_location {
		    DW_OP_const2u 0x5678
		    DW_OP_stack_value
		    DW_OP_piece 2
		    DW_OP_const1u 2
		    DW_OP_stack_value
		    DW_OP_piece 1
		    DW_OP_const1u 3
		    DW_OP_stack_value
		    DW_OP_piece 1
		} SPECIAL_expr
	    }

	    DW_TAG_variable {
		DW_AT_name p
		DW_AT_type :$ptr_label
		DW_AT_location {
		    DW_OP_GNU_implicit_pointer $var_label 2
		} SPECIAL_expr
	    }
	}
    }
}

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

if {![runto_main]} {
    return
}

# Determine byte order.
set endian [get_endianness]

# Access the second byte of s through an implicit pointer to the third
# byte of s, using a negative offset.  Compare that to the second byte of
# the short integer 0x5678 in target byte order.
switch $endian { little {set val 0x56} big {set val 0x78} }
gdb_test "p/x p\[-1\]" " = $val"