gdb/testsuite/gdb.base/code_elim.exp

# Copyright 2002-2021 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/>.  */

# code_elim.exp -- tests that GDB can handle executables where some data/code
#                  has been eliminated by the linker.

set testfile1 code_elim1
set testfile2 code_elim2
set srcfile1 ${testfile1}.c
set srcfile2 ${testfile2}.c
set binfile1 [standard_output_file ${testfile1}]
set binfile2 [standard_output_file ${testfile2}]
set opts [list debug]
lappend opts "additional_flags=-ffunction-sections"
lappend opts "additional_flags=-fdata-sections"
lappend opts "additional_flags=-Wl,-gc-sections"
lappend opts "additional_flags=-Wl,-e,main"

# Place variables in .data instead of .sdata.
if {[istarget "riscv*-*-*"]} {
   lappend opts "additional_flags=-msmall-data-limit=0"
}

remote_exec build "rm -f ${binfile1}"
remote_exec build "rm -f ${binfile2}"

if { [gdb_compile "${srcdir}/${subdir}/${srcfile1}" "${binfile1}" executable $opts] != "" } {
     untested "failed to compile"
     return -1
}

if { [gdb_compile "${srcdir}/${subdir}/${srcfile2}" "${binfile2}" executable $opts] != "" } {
     untested "failed to compile"
     return -1
}

proc not_null_var_address { var } {

    # Same as get_var_address, expect that it reports a failure if a null
    # address is returned by gdb.

    set address [get_var_address $var]
    regexp "0x\[0-9a-fA-F\]+" $address address
    if { "$address" == "0x0" } {
	fail "$var has null address"
    }
}

proc test_eliminated_var { var } {
    global gdb_prompt hex

    # Match output 'No symbol "${var}" in current context'

    gdb_test_multiple "print &${var}" "test eliminated var ${var}" {
	-re "No symbol \"${var}\" in current context\\.\[\r\n\]+${gdb_prompt} $" {
	    pass "test eliminated var ${var}"
	}
	-re "\\\$\[0-9\]+ = \\(.*\\) (0|$hex)( <${var}>)?\[\r\n\]+${gdb_prompt} $" {
	    fail "test eliminated var ${var}"
	}
    }
}

# Check that the code and data eliminated in binfile1 are not included
# into partial symtab... and that non-eliminated symbols are still there.

gdb_exit
gdb_start

gdb_test "symbol-file ${binfile1}" \
	"Reading symbols from .*${testfile1}\\.\\.\\.(|\r\nUsing host libthread_db library .*libthread_db.so.*\\.)" \
	"symbol-file ${testfile1}"

with_test_prefix "single psymtabs" {
    test_eliminated_var my_global_symbol
    test_eliminated_var my_static_symbol
    test_eliminated_var my_global_func
    not_null_var_address main
}

# Same thing for symtabs

gdb_exit
global GDBFLAGS
set saved_gdbflags $GDBFLAGS
set GDBFLAGS "$GDBFLAGS --readnow $binfile1"
gdb_start
set GDBFLAGS $saved_gdbflags

with_test_prefix "single symtabs" {
    test_eliminated_var my_global_symbol
    test_eliminated_var my_static_symbol
    test_eliminated_var my_global_func
    not_null_var_address main
}

# binfile2 contains the symbols that have been eliminated in binfile1. Check
# the eliminated symbols does not hide these valid ones.

gdb_exit
gdb_start

with_test_prefix "order1" {
    gdb_test "add-symbol-file ${binfile1} 0x100000 -s .bss 0x120000" \
	    "Reading symbols from .*${testfile1}\\.\\.\\." \
	    "add-symbol-file ${testfile1} 0x100000" \
	    "add symbol table from file \".*${testfile1}\" at.*\\(y or n\\) " \
	    "y"

    gdb_test "add-symbol-file ${binfile2} 0x200000 -s .data 0x210000 -s .bss 0x220000" \
	    "Reading symbols from .*${testfile2}\\.\\.\\." \
	    "add-symbol-file ${testfile2} 0x200000" \
	    "add symbol table from file \".*${testfile2}\" at.*\\(y or n\\) " \
	    "y"

    not_null_var_address my_global_symbol
    not_null_var_address my_static_symbol
    not_null_var_address my_global_func
    not_null_var_address main
}

# Same thing, but loading binfile2 before binfile1.

gdb_exit
gdb_start

with_test_prefix "order2" {
    gdb_test "add-symbol-file ${binfile2} 0x200000 -s .data 0x210000 -s .bss 0x220000" \
	    "Reading symbols from .*${testfile2}\\.\\.\\." \
	    "add-symbol-file ${testfile2} 0x200000" \
	    "add symbol table from file \".*${testfile2}\" at.*\\(y or n\\) " \
	    "y"

    gdb_test "add-symbol-file ${binfile1} 0x100000 -s .bss 0x120000" \
	    "Reading symbols from .*${testfile1}\\.\\.\\." \
	    "add-symbol-file ${testfile1} 0x100000" \
	    "add symbol table from file \".*${testfile1}\" at.*\\(y or n\\) " \
	    "y"

    not_null_var_address my_global_symbol
    not_null_var_address my_static_symbol
    not_null_var_address my_global_func
    not_null_var_address main
}