# Copyright 2020-2021 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/>.

# Magic constants used to calculate a starting address when linking
# "jit" shared libraries.  When loaded, will be mapped by jit-elf-main
# to the same address.

set jit_load_address   0x7000000
set jit_load_increment 0x1000000

# Compile jit-elf-main.c as an executable.
#
# BINSUFFIX is appended to the binary name.
# OPTIONS is passed to gdb_compile when compiling the program.
#
# On success, return 0.
# On failure, return -1.
proc compile_jit_main {main_srcfile main_binfile options} {
    global jit_load_address jit_load_increment

    set options [concat \
	$options \
	additional_flags=-DLOAD_ADDRESS=$jit_load_address \
	additional_flags=-DLOAD_INCREMENT=$jit_load_increment \
	debug]

    if { [gdb_compile ${main_srcfile} ${main_binfile} \
	      executable $options] != "" } {
	set f [file tail $main_binfile]
	untested "failed to compile $f"
	return -1
    }

    return 0
}

# Compile jit-elf-main.c as a shared library.
#
# OPTIONS is passed to gdb_compile when compiling the program.
#
# On success, return 0.
# On failure, return -1.
proc compile_jit_elf_main_as_so {main_solib_srcfile main_solib_binfile options} {
    global jit_load_address jit_load_increment

    set options [list \
	additional_flags="-DMAIN=jit_dl_main" \
	additional_flags=-DLOAD_ADDRESS=$jit_load_address \
	additional_flags=-DLOAD_INCREMENT=$jit_load_increment \
	debug]

    if { [gdb_compile_shlib ${main_solib_srcfile} ${main_solib_binfile} \
	      $options] != "" } {
	set f [file tail $main_solib_binfile]
	untested "failed to compile shared library $f"
	return -1
    }

    return 0
}

# Compile jit-elf-solib.c as a shared library in multiple copies and
# upload them to the target.
#
# On success, return a list of target path to the shared libraries.
# On failure, return -1.
proc compile_and_download_n_jit_so {jit_solib_basename jit_solib_srcfile count} {
    global jit_load_address jit_load_increment
    set binfiles_target {}

    for {set i 1} {$i <= $count} {incr i} {
	set binfile [standard_output_file ${jit_solib_basename}.$i.so]

	# Note: compiling without debug info by default: some test
	# do symbol renaming by munging on ELF symbol table, and that
	# wouldn't work for .debug sections.  Also, output for "info
	# function" changes when debug info is present.
	set addr [format 0x%x [expr $jit_load_address + $jit_load_increment * [expr $i-1]]]
	# Using -Ttext-segment flag to ask linked to relocate everything
	# in the compiled shared library against a fixed base address.  Combined
	# with mapping the resulting binary to the same fixed base it allows
	# to dynamically execute functions from it without any further adjustments.
	set options [list \
	    additional_flags=-DFUNCTION_NAME=[format "jit_function_%04d" $i] \
	    additional_flags=-Xlinker \
	    additional_flags=-Ttext-segment=$addr]
	if { [gdb_compile_shlib ${jit_solib_srcfile} ${binfile} \
		  $options] != "" } {
	    set f [file tail $binfile]
	    untested "failed to compile shared library $f"
	    return -1
	}

	set path [gdb_remote_download target ${binfile}]
	lappend binfiles_target $path
    }

    return $binfiles_target
}