Add the stack_usage.tcl script for analyzing the output of objdump on the
amalgamation and estimating the sizes of stack frames on each function.
FossilOrigin-Name: 030013ff0c7af5f146a64f9ede31297ff003e0c4
diff --git a/tool/stack_usage.tcl b/tool/stack_usage.tcl
new file mode 100644
index 0000000..b3574f0
--- /dev/null
+++ b/tool/stack_usage.tcl
@@ -0,0 +1,98 @@
+#!/usr/bin/tclsh
+#
+# Parse the output of
+#
+# objdump -d sqlite3.o
+#
+# for x64 and generate a report showing:
+#
+# (1) Stack used by each function
+# (2) Recursion paths and their aggregate stack depth
+#
+set getStack 0
+while {![eof stdin]} {
+ set line [gets stdin]
+ if {[regexp {^[0-9a-f]+ <([^>]+)>:\s*$} $line all procname]} {
+ set curfunc $procname
+ set root($curfunc) 1
+ set calls($curfunc) {}
+ set calledby($curfunc) {}
+ set recursive($curfunc) {}
+ set stkdepth($curfunc) 0
+ set getStack 1
+ continue
+ }
+ if {[regexp {callq? +[0-9a-z]+ <([^>]+)>} $line all other]} {
+ set key [list $curfunc $other]
+ set callpair($key) 1
+ unset -nocomplain root($curfunc)
+ continue
+ }
+ if {[regexp {sub +\$(0x[0-9a-z]+),%[er]sp} $line all xdepth]} {
+ if {$getStack} {
+ scan $xdepth %x depth
+ set stkdepth($curfunc) $depth
+ set getStack 0
+ }
+ continue
+ }
+}
+
+puts "****************** Stack Usage By Function ********************"
+set sdlist {}
+foreach f [array names stkdepth] {
+ lappend sdlist [list $stkdepth($f) $f]
+}
+foreach sd [lsort -integer -decr -index 0 $sdlist] {
+ foreach {depth fname} $sd break
+ puts [format {%6d %s} $depth $fname]
+}
+
+puts "****************** Stack Usage By Recursion *******************"
+foreach key [array names callpair] {
+ foreach {from to} $key break
+ lappend calls($from) $to
+ # lappend calledby($to) $from
+}
+proc all_descendents {root} {
+ global calls recursive
+ set todo($root) $root
+ set go 1
+ while {$go} {
+ set go 0
+ foreach f [array names todo] {
+ set path $todo($f)
+ unset todo($f)
+ if {![info exists calls($f)]} continue
+ foreach x $calls($f) {
+ if {$x==$root} {
+ lappend recursive($root) [concat $path $root]
+ } elseif {![info exists d($x)]} {
+ set go 1
+ set todo($x) [concat $path $x]
+ set d($x) 1
+ }
+ }
+ }
+ }
+ return [array names d]
+}
+set pathlist {}
+foreach f [array names recursive] {
+ all_descendents $f
+ foreach m $recursive($f) {
+ set depth 0
+ foreach b [lrange $m 0 end-1] {
+ set depth [expr {$depth+$stkdepth($b)}]
+ }
+ lappend pathlist [list $depth $m]
+ }
+}
+foreach path [lsort -integer -decr -index 0 $pathlist] {
+ foreach {depth m} $path break
+ set first [lindex $m 0]
+ puts [format {%6d %s %d} $depth $first $stkdepth($first)]
+ foreach b [lrange $m 1 end] {
+ puts " $b $stkdepth($b)"
+ }
+}