gdb/testsuite/gdb.arch/riscv-reg-aliases.exp

# Copyright 2018-2021 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/>.

if {![istarget "riscv*-*-*"]} {
    verbose "Skipping ${gdb_test_file_name}."
    return
}

standard_testfile

if {[prepare_for_testing "failed to prepare" $testfile $srcfile debug]} {
    return -1
}

if ![runto_main] then {
   return 0
}


# A list for all the integer register names and their aliases.  The format is
# a list with each entry being itself a list, the first item being the primary
# name of a register (the name GDB uses by default), and the second entry
# being a list of register aliases.
set xreg_names \
{ { ra {x1} } { sp {x2} } { gp {x3} } { tp {x4} } { t0 {x5} } \
  { t1 {x6} } { t2 {x7} } { fp {x8 s0} } { s1 {x9} } { a0 {x10} } \
  { a1 {x11} } { a2 {x12} } { a3 {x13} } { a4 {x14} } { a5 {x15} } \
  { a6 {x16} } { a7 {x17} } { s2 {x18} } { s3 {x19} } { s4 {x20} } \
  { s5 {x21} } { s6 {x22} } { s7 {x23} } { s8 {x24} } { s9 {x25} } \
  { s10 {x26} } { s11 {x27} } { t3 {x28} } { t4 {x29} } { t5 {x30} } \
  { t6 {x31} } }

# This is just like XREG_NAMES, except it contains all the floating point
# register names and their aliases.
set freg_names \
{ { ft0 {f0} } { ft1 {f1} } { ft2 {f2} } { ft3 {f3} } { ft4 {f4} } \
  { ft5 {f5} } { ft6 {f6} } { ft7 {f7} } { fs0 {f8} } { fs1 {f9} } \
  { fa0 {f10} } { fa1 {f11} } { fa2 {f12} } { fa3 {f13} } { fa4 {f14} } \
  { fa5 {f15} } { fa6 {f16} } { fa7 {f17} } { fs2 {f18} } { fs3 {f19} } \
  { fs4 {f20} } { fs5 {f21} } { fs6 {f22} } { fs7 {f23} } { fs8 {f24} } \
  { fs9 {f25} } { fs10 {f26} } { fs11 {f27} } { ft8 {f28} } { ft9 {f29} } \
  { ft10 {f30} } { ft11 {f31} } }

# Check that the zero register (and its x0 alias) both contain the
# value 0.
proc check_zero_register_value {testname} {
    gdb_test "p/d \$zero" " = 0" "check \$zero: ${testname}"
    gdb_test "p/d \$x0" " = 0" "check \$x0: ${testname}"
}

# Set all of the registers in REG_SET to zero.  Confirm that the value of zero
# can be read back using the primary name, and from all of the alias names.
#
# For some architectures (RV64, RV128) the float registers have union type,
# and we need to read/write using a ".float" extension.  This is passed in
# REG_EXTENSION.  If no extension is needed then REG_EXTENSION is the empty
# string.
proc check_setting_registers_to_zero { reg_set reg_extension } {
    foreach reg_desc ${reg_set} {
	set primary_name [lindex ${reg_desc} 0]
	set alias_names [lindex ${reg_desc} 1]

	gdb_test_no_output "set \$${primary_name}${reg_extension} = 0" \
	    "set register ${primary_name} to an initial value of zero"
	gdb_test "p/d \$${primary_name}${reg_extension}" " = 0" \
	    "check the initial value of ${primary_name} is now zero"

	foreach reg_alias ${alias_names} {
	    gdb_test "p/d \$${reg_alias}${reg_extension}" " = 0" \
		"check the initial value of ${reg_alias} is now zero"
	}
    }
}

# Set all of the registers in REG_SET to a new value (the value starts at
# REG_VALUE and is incremented after each test).  Then confirm that the new
# value can be read back using the primary name, and from all of the alias
# names.
#
# Next, set each register in REG_SET using each of its alias names, then
# confirm that the value can be read back using both the primary name, and all
# of the aliases.
#
# The REG_EXTENSION field is used as in CHECK_SETTING_REGISTERS_TO_ZERO.
proc check_setting_registers_to_value { reg_set reg_extension reg_value } {
    foreach reg_desc ${reg_set} {
	set primary_name [lindex ${reg_desc} 0]
	set alias_names [lindex ${reg_desc} 1]

	# Set value through the primary register name, and check that all
	# the aliases see the same value.
	set reg_value [incr reg_value]
	gdb_test_no_output "set \$${primary_name}${reg_extension} = $reg_value" \
	    "write non-zero value to ${primary_name}"
	gdb_test "p/d \$${primary_name}${reg_extension}" " = $reg_value" \
	    "read ${primary_name} after non-zero write to ${primary_name}"
	foreach reg_alias ${alias_names} {
	    gdb_test "p/d \$${reg_alias}${reg_extension}" " = $reg_value" \
		"read ${reg_alias} after non-zero write to ${primary_name}"
	}

	# For each alias, set a new value, and check that the primary
	# register name, and all the other aliases, see the new value.
	foreach reg_alias ${alias_names} {
	    set reg_value [incr reg_value]

	    gdb_test_no_output "set \$${reg_alias}${reg_extension} = $reg_value" \
		"write non-zero value to ${reg_alias}"

	    gdb_test "p/d \$${primary_name}${reg_extension}" " = $reg_value" \
		"read ${primary_name} after non-zero write to ${reg_alias}"

	    foreach other_reg_alias ${alias_names} {
		gdb_test "p/d \$${other_reg_alias}${reg_extension}" " = $reg_value" \
		    "read ${other_reg_alias} after non-zero write to ${reg_alias}"
	    }
	}
    }
}

# First, some testing of the zero register.  This register should
# always read as zero, and should swallow any attempt to write a
# non-zero value to the register.

check_zero_register_value "before any writes"

gdb_test_no_output "set \$zero = 123" \
    "write to the \$zero register"

check_zero_register_value "after write to \$zero"

gdb_test_no_output "set \$x0 = 123" \
    "write to the \$x0 register"

check_zero_register_value "after write to \$x0"

# Some RISC-V variants model the fregs as a union (RV64, RV128).  In this case
# we should access the register using 'REG_NAME.float'.  In the following we
# figure out if the field name is needed or not by looking at how GDB prints
# on register.
set skip_freg_tests 0
set freg_extension "INVALID"
set message "check format of float registers"
gdb_test_multiple "info registers \$ft0" $message {
    -re "Invalid register `ft0'\r\n$gdb_prompt $" {
	set skip_freg_tests 1
	set freg_extension "NONE"
	pass $message
    }
    -re "ft0 \+\[0-9\]\+.*\r\n$gdb_prompt $" {
	set freg_extension ""
	pass $message
    }
    -re "ft0 \+\{float = .*\r\n$gdb_prompt $" {
	set freg_extension ".float"
	pass $message
    }
}
gdb_assert ![string eq "${freg_extension}" "INVALID"] \
    "check that floating point format has been understood"

# Now check that we can write zero, and read zero back to all of the integer
# and floating point registers.
check_setting_registers_to_zero ${xreg_names} ""

if { ! $skip_freg_tests } {
    check_setting_registers_to_zero ${freg_names} ${freg_extension}
}

# Set each register in turn to a new value, and confirm that the new value can
# be read back from the primary name, and from all of the alias names.  The
# value passed in to each test invocation here is arbitrary, they are
# significantly different so that the float tests don't reuse value from the
# integer tests.
check_setting_registers_to_value ${xreg_names} "" 100

if { ! $skip_freg_tests } {
    check_setting_registers_to_value ${freg_names} ${freg_extension} 500
}