From 0b25e810ed73334d30f99ba7073f21369b33ab18 Mon Sep 17 00:00:00 2001 From: Ron Yorston Date: Mon, 8 Mar 2021 19:30:57 +0000 Subject: [PATCH] bloat-o-meter: avoid double counting Disable 'echo' in the default config, run 'make baseline', then re-enable 'echo' and run 'make bloatcheck': function old new delta .rodata 182521 182622 +101 packed_usage 33714 33792 +78 applet_main 3168 3176 +8 applet_names 2730 2735 +5 applet_suid 99 100 +1 applet_install_loc 198 199 +1 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 6/0 up/down: 194/0) Total: 194 bytes text data bss dec hex filename 955052 4195 1808 961055 eaa1f busybox_old 955153 4195 1808 961156 eaa84 busybox_unstripped The Total bytes value doesn't equal the change in the size of the binary. The packed_usage and applet_* items are in .rodata and are counted twice. With this modified bloat-o-meter the size of named items is deducted from .rodata: function old new delta packed_usage 33714 33792 +78 applet_main 3168 3176 +8 .rodata 105105 105113 +8 applet_names 2730 2735 +5 applet_suid 99 100 +1 applet_install_loc 198 199 +1 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 6/0 up/down: 101/0) Total: 101 bytes text data bss dec hex filename 955052 4195 1808 961055 eaa1f busybox_old 955153 4195 1808 961156 eaa84 busybox_unstripped v2: Sections numbered less than 10 were always being omitted from consideration because splitting "[ 1] .interp" leaves "1]" in x[1] where the section name is expected. This wasn't a problem for .rodata (numbered 15 in my testing) but let's fix it anyway. Signed-off-by: Ron Yorston Signed-off-by: Denys Vlasenko --- scripts/bloat-o-meter | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) diff --git a/scripts/bloat-o-meter b/scripts/bloat-o-meter index cb861b8e9..b4a1d2811 100755 --- a/scripts/bloat-o-meter +++ b/scripts/bloat-o-meter @@ -43,7 +43,15 @@ if f1 is None or f2 is None: sym_args = " ".join(sys.argv[3 + flag_timing + dashes:]) def getsizes(file): - sym, alias, lut = {}, {}, {} + sym, alias, lut, section = {}, {}, {}, {} + for l in os.popen("readelf -W -S " + file).readlines(): + x = l.replace("[ ", "[", 1).split() + if len(x)<6: continue + # Should take these into account too! + #if x[1] not in [".text", ".rodata", ".symtab", ".strtab"]: continue + if x[1] not in [".rodata"]: continue + sym[x[1]] = {"addr" : int(x[3], 16), "size" : int(x[5], 16)} + section[x[0][1:-1]] = {"name" : x[1]} for l in os.popen("readelf -W -s %s %s" % (sym_args, file)).readlines(): l = l.strip() if not (len(l) and l[0].isdigit() and len(l.split()) == 8): @@ -59,6 +67,10 @@ def getsizes(file): else: sym[name] = {"addr" : value, "size": size} lut[(value, size)] = 0 + # If this item is in a known section deduct its size from + # the size of the section + if ndx in section: + sym[section[ndx]["name"]]["size"] -= size for addr, sz in iter(alias.keys()): # If the non-GLOBAL sym has an implementation elsewhere then # it's an alias, disregard it. @@ -66,13 +78,6 @@ def getsizes(file): # If this non-GLOBAL sym does not have an implementation at # another address, then treat it as a normal symbol. sym[alias[(addr, sz)]["name"]] = {"addr" : addr, "size": sz} - for l in os.popen("readelf -W -S " + file).readlines(): - x = l.split() - if len(x)<6: continue - # Should take these into account too! - #if x[1] not in [".text", ".rodata", ".symtab", ".strtab"]: continue - if x[1] not in [".rodata"]: continue - sym[x[1]] = {"addr" : int(x[3], 16), "size" : int(x[5], 16)} return sym if flag_timing: