gcc/testsuite/lib/print-stack.exp

# Copyright (C) 2024-2025 Free Software Foundation, Inc.
#  Contributed by David Malcolm <dmalcolm@redhat.com>.

# 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 GCC; see the file COPYING3.  If not see
# <http://www.gnu.org/licenses/>.

# Get the 1-based line for LINENUM from FILENAME as a string

proc get_line { filename linenum } {
    set f [open $filename]
    set lines [split [read $f] \n]
    close $f
    return [lindex $lines [expr $linenum - 1] ]
}

# Print a backtrace of the Tcl interpreter's stack, showing
# frames, levels, source file and line where available.
#
# This isn't used anywhere, but is occasionally very helpful
# to use when debugging.

proc print_stack_backtrace {} {
    set current_frame_level [info frame]
    puts "VVV START OF BACKTRACE VVV"
    for {set i [expr $current_frame_level - 1]} {$i > 0} {incr i -1} {
	set frame [info frame $i]
	if { [dict exists $frame "level"] } {
	    set level_num [dict get $frame "level"]
	    set relative_level_offset [expr 1 - $level_num]
	    set level [info level $relative_level_offset]
	    set procname [lindex $level 0]
	    # TODO: args = rest of $level, but this can be very long
	} else {
	    set procname ""
	}
	set suffix ""
	if { $procname != "" } {
	    set suffix " in proc $procname"
	}
	if { [dict get $frame "type"] == "source" } {
	    set fname [dict get $frame "file"]
	    set line [dict get $frame "line"]
	    puts "  $fname:$line: frame $i$suffix"
	    puts "    $line | [get_line $fname $line]"
	} else {
	    set type [dict get $frame "type"]
	    puts "  <$type>: frame $i$suffix"
	}
    }
    puts "^^^  END OF BACKTRACE  ^^^"
}