add imported avstack version with minor patches

avstack.pl

+#!/usr/bin/perl -w
+# avstack.pl: AVR stack checker
+# Copyright (C) 2013 Daniel Beer <dlbeer@gmail.com>
+# Copyright (C) 2018 Daniel Friesel <daniel.friesel@uni-osnabrueck.de>
+#
+# Permission to use, copy, modify, and/or distribute this software for
+# any purpose with or without fee is hereby granted, provided that the
+# above copyright notice and this permission notice appear in all
+# copies.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
+# WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
+# WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
+# AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
+# DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
+# PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+# TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+# PERFORMANCE OF THIS SOFTWARE.
+#
+# Usage
+# -----
+#
+# This script requires that you compile your code with -fstack-usage.
+# This results in GCC/G++ generating a .su file for each .o file. Once you
+# have these, do:
+#
+#    ./avstack.pl <objdump binary> <call cost> <object files ...>
+#
+# This will disassemble .o files to construct a call graph, and read
+# frame size information from .su. The call graph is traced to find, for
+# each function:
+#
+#    - Call height: the maximum call height of any callee, plus 1
+#      (defined to be 1 for any function which has no callees).
+#
+#    - Inherited frame: the maximum *inherited* frame of any callee, plus
+#      the GCC-calculated frame size of the function in question.
+#
+# Using these two pieces of information, we calculate a cost (estimated
+# peak stack usage) for calling the function. Functions are then listed
+# on stdout in decreasing order of cost.
+#
+# Functions which are recursive are marked with an 'R' to the left of
+# them. Their cost is calculated for a single level of recursion.
+#
+# The peak stack usage of your entire program can usually be estimated
+# as the stack cost of "main", plus the maximum stack cost of any
+# interrupt handler which might execute.
+
+use strict;
+use warnings;
+use 5.010;
+
+# Configuration: set these as appropriate for your architecture/project.
+
+my $objdump = shift;
+my $call_cost = shift;
+
+# First, we need to read all object and corresponding .su files. We're
+# gathering a mapping of functions to callees and functions to frame
+# sizes. We're just parsing at this stage -- callee name resolution
+# comes later.
+
+my %frame_size;     # "func@file" -> size
+my %call_graph;     # "func@file" -> {callees}
+my %addresses;      # "addr@file" -> "func@file"
+
+my %global_name;    # "func" -> "func@file"
+my %ambiguous;      # "func" -> 1
+
+foreach (@ARGV) {
+    # Disassemble this object file to obtain a callees. Sources in the
+    # call graph are named "func@file". Targets in the call graph are
+    # named either "offset@file" or "funcname". We also keep a list of
+    # the addresses and names of each function we encounter.
+    my $objfile = $_;
+    my $source;
+
+    open(DISASSEMBLY, "$objdump -Cdr $objfile|") ||
+	die "Can't disassemble $objfile";
+    while (<DISASSEMBLY>) {
+	chomp;
+
+	if (/^([0-9a-fA-F]+) <(.*)>:/) {
+	    my $a = $1;
+	    my $name = $2;
+
+	    $source = "$name\@$objfile";
+	    $call_graph{$source} = {};
+	    $ambiguous{$name} = 1 if defined($global_name{$name});
+	    $global_name{$name} = "$name\@$objfile";
+
+	    $a =~ s/^0*//;
+	    $addresses{"$a\@$objfile"} = "$name\@$objfile";
+	}
+
+	if (/: R_[A-Za-z0-9_]+_(?:CALL|PLT32|ABS16)[ \t]+(.*)/) {
+	    my $t = $1;
+
+	    if ($t eq ".text") {
+		$t = "\@$objfile";
+	    } elsif ($t =~ /^\.text\+0x(.*)$/) {
+		$t = "$1\@$objfile";
+	    }
+
+		 $t =~ s{-0x4$}{};
+
+	    $call_graph{$source}->{$t} = 1;
+	}
+    }
+    close(DISASSEMBLY);
+
+    # Extract frame sizes from the corresponding .su file.
+    if ($objfile =~ /^(.*).o$/) {
+	my $sufile = "$1.su";
+
+	open(SUFILE, "<$sufile") || die "Can't open $sufile";
+	while (<SUFILE>) {
+		if (m{ ^ [^:]+ : \d+ : \d+ : [^\t]+? \s (?<name> \S+ ) \( .*? \)
+			(?: \s* \[with [^]]*\])?
+			\t
+			(?<size> \d+ )}x) {
+			$frame_size{"$+{name}\@$objfile"} = $+{size} + $call_cost;
+		} else {
+			say "No match $_";
+		}
+	}
+	close(SUFILE);
+    }
+}
+
+# In this step, we enumerate each list of callees in the call graph and
+# try to resolve the symbols. We omit ones we can't resolve, but keep a
+# set of them anyway.
+
+my %unresolved;
+
+foreach (keys %call_graph) {
+    my $from = $_;
+    my $callees = $call_graph{$from};
+    my %resolved;
+
+    foreach (keys %$callees) {
+	my $t = $_;
+
+	if (defined($addresses{$t})) {
+	    $resolved{$addresses{$t}} = 1;
+	} elsif (defined($global_name{$t})) {
+	    $resolved{$global_name{$t}} = 1;
+	    warn "Ambiguous resolution: $t" if defined ($ambiguous{$t});
+	} elsif (defined($call_graph{$t})) {
+	    $resolved{$t} = 1;
+	} else {
+	    $unresolved{$t} = 1;
+	}
+    }
+
+    $call_graph{$from} = \%resolved;
+}
+
+# Create fake edges and nodes to account for dynamic behaviour.
+$call_graph{"INTERRUPT"} = {};
+
+foreach (keys %call_graph) {
+    $call_graph{"INTERRUPT"}->{$_} = 1 if /^__vector_/;
+}
+
+# Trace the call graph and calculate, for each function:
+#
+#    - inherited frames: maximum inherited frame of callees, plus own
+#      frame size.
+#    - height: maximum height of callees, plus one.
+#    - recursion: is the function called recursively (including indirect
+#      recursion)?
+
+my %has_caller;
+my %visited;
+my %total_cost;
+my %call_depth;
+
+sub trace {
+    my $f = shift;
+
+    if ($visited{$f}) {
+	$visited{$f} = "R" if $visited{$f} eq "?";
+	return;
+    }
+
+    $visited{$f} = "?";
+
+    my $max_depth = 0;
+    my $max_frame = 0;
+
+    my $targets = $call_graph{$f} || die "Unknown function: $f";
+    if (defined($targets)) {
+	foreach (keys %$targets) {
+	    my $t = $_;
+
+	    $has_caller{$t} = 1;
+	    trace($t);
+
+	    my $is = $total_cost{$t};
+	    my $d = $call_depth{$t};
+
+	    $max_frame = $is if $is > $max_frame;
+	    $max_depth = $d if $d > $max_depth;
+	}
+    }
+
+    $call_depth{$f} = $max_depth + 1;
+    $total_cost{$f} = $max_frame + ($frame_size{$f} || 0);
+    $visited{$f} = " " if $visited{$f} eq "?";
+}
+
+foreach (keys %call_graph) { trace $_; }
+
+# Now, print results in a nice table.
+printf "  %-30s %8s %8s %8s\n",
+    "Func", "Cost", "Frame", "Height";
+print "------------------------------------";
+print "------------------------------------\n";
+
+my $max_iv = 0;
+my $main = 0;
+
+foreach (sort { $total_cost{$b} <=> $total_cost{$a} } keys %visited) {
+    my $name = $_;
+
+    if (/^(.*)@(.*)$/) {
+	$name = $1 unless $ambiguous{$name};
+    }
+
+    my $tag = $visited{$_};
+    my $cost = $total_cost{$_};
+
+    $name = $_ if $ambiguous{$name};
+    $tag = ">" unless $has_caller{$_};
+
+    if (/^__vector_/) {
+	$max_iv = $cost if $cost > $max_iv;
+    } elsif (/^main@/) {
+	$main = $cost;
+    }
+
+    if ($ambiguous{$name}) { $name = $_; }
+
+    printf "%s %-30s %8d %8d %8d\n", $tag, $name, $cost,
+	$frame_size{$_} || 0, $call_depth{$_};
+}
+
+print "\n";
+
+print "Peak execution estimate (main + worst-case IV):\n";
+printf "  main = %d, worst IV = %d, total = %d\n",
+      $total_cost{$global_name{"main"}},
+      $total_cost{"INTERRUPT"},
+      $total_cost{$global_name{"main"}} + $total_cost{"INTERRUPT"};
+
+print "\n";
+
+print "The following functions were not resolved:\n";
+foreach (keys %unresolved) { print "  $_\n"; }