cmd/go: Go 1.11 stripped binaries 12% larger that Go 1.10

[davecheney]

Please answer these questions before submitting your issue. Thanks!

What version of Go are you using (go version)?

go/1.10 & go/1.11

Does this issue reproduce with the latest release?

yes

What operating system and processor architecture are you using (go env)?

darwin/amd64

What did you do?

go get -d github.com/heptio/contour
cd $GOPATH/src/github.com/heptio/contour
dep ensure -vendor-only

What did you expect to see?

% go1.10 build  -o contour1.10 ./cmd/contour && go1.11 build -o contour1.11 ./cmd/contour
% ls -al ./contour*
-rwxr-xr-x  1 dfc  staff  47355140 21 Sep 08:02 ./contour1.10
-rwxr-xr-x  1 dfc  staff  42406532 21 Sep 08:02 ./contour1.11

Unstripped the Go 1.11 binary is 10.45% smaller, however

% go1.10 build -ldflags='-s -w' -o contour1.10 ./cmd/contour && go1.11 build -ldflags='-s -w' -o contour1.11 ./cmd/contour
% ls -al ./contour*
-rwxr-xr-x  1 dfc  staff  32359684 21 Sep 08:06 ./contour1.10
-rwxr-xr-x  1 dfc  staff  36328068 21 Sep 08:07 ./contour1.11

The stripped and DWARF less binary is 12% larger.

[davecheney]

bloaty suggests the extra size is coming from __gopclntab

% bloaty contour1.10
     VM SIZE                              FILE SIZE
 --------------                        --------------
  43.5%  13.5Mi __TEXT,__text           13.5Mi  43.7%
  26.0%  8.06Mi __TEXT,__gopclntab      8.06Mi  26.1%
  14.3%  4.43Mi __TEXT,__rodata         4.43Mi  14.3%
  11.9%  3.70Mi String Table            3.70Mi  12.0%
   2.4%   760Ki Symbol Table             760Ki   2.4%
   1.0%   314Ki __DATA,__noptrdata       314Ki   1.0%
   0.5%   142Ki __DATA,__bss                 0   0.0%
   0.3%  79.8Ki __DATA,__data           79.8Ki   0.3%
   0.1%  43.8Ki __TEXT,__typelink       43.8Ki   0.1%
   0.1%  18.9Ki __TEXT,__itablink       18.9Ki   0.1%
   0.0%  12.7Ki __DATA,__noptrbss            0   0.0%
   0.0%  2.89Ki [__TEXT]                2.78Ki   0.0%
   0.0%  1.73Ki [Mach-O Headers]        1.83Ki   0.0%
   0.0%       0 [Unmapped]                 800   0.0%
   0.0%     464 __DATA,__nl_symbol_ptr     464   0.0%
   0.0%     452 Indirect Symbol Table      452   0.0%
   0.0%     330 __TEXT,__symbol_stub1      330   0.0%
   0.0%      87 [__DATA]                    63   0.0%
 100.0%  31.0Mi TOTAL                   30.9Mi 100.0%
% bloaty contour1.11
     VM SIZE                              FILE SIZE
 --------------                        --------------
  39.2%  13.6Mi __TEXT,__text           13.6Mi  39.4%
  32.6%  11.3Mi __TEXT,__gopclntab      11.3Mi  32.8%
  13.6%  4.74Mi __TEXT,__rodata         4.74Mi  13.7%
  10.7%  3.71Mi String Table            3.71Mi  10.7%
   2.2%   768Ki Symbol Table             768Ki   2.2%
   0.9%   315Ki __DATA,__noptrdata       315Ki   0.9%
   0.4%   143Ki __DATA,__bss                 0   0.0%
   0.2%  79.3Ki __DATA,__data           79.3Ki   0.2%
   0.1%  42.4Ki __TEXT,__typelink       42.4Ki   0.1%
   0.1%  18.9Ki __TEXT,__itablink       18.9Ki   0.1%
   0.0%  13.4Ki __DATA,__noptrbss            0   0.0%
   0.0%  3.80Ki [__TEXT]                3.70Ki   0.0%
   0.0%  1.73Ki [Mach-O Headers]        1.83Ki   0.0%
   0.0%       0 [Unmapped]                 960   0.0%
   0.0%     688 __DATA,__nl_symbol_ptr     688   0.0%
   0.0%     676 Indirect Symbol Table      676   0.0%
   0.0%     498 __TEXT,__symbol_stub1      498   0.0%
   0.0%      79 [__DATA]                    63   0.0%
 100.0%  34.8Mi TOTAL                   34.6Mi 100.0%

[davecheney]

For reference, tip is similar to go 1.11

% go build -ldflags='-s -w' -o contour.tip ./cmd/contour
% bloaty contour.tip
     VM SIZE                              FILE SIZE
 --------------                        --------------
  39.2%  13.7Mi __TEXT,__text           13.7Mi  39.4%
  32.6%  11.3Mi __TEXT,__gopclntab      11.3Mi  32.7%
  13.6%  4.74Mi __TEXT,__rodata         4.74Mi  13.7%
  10.7%  3.72Mi String Table            3.72Mi  10.7%
   2.2%   769Ki Symbol Table             769Ki   2.2%
   0.9%   315Ki __DATA,__noptrdata       315Ki   0.9%
   0.4%   143Ki __DATA,__bss                 0   0.0%
   0.2%  79.3Ki __DATA,__data           79.3Ki   0.2%
   0.1%  42.4Ki __TEXT,__typelink       42.4Ki   0.1%
   0.1%  19.0Ki __TEXT,__itablink       19.0Ki   0.1%
   0.0%  13.4Ki __DATA,__noptrbss            0   0.0%
   0.0%  4.45Ki [__TEXT]                4.35Ki   0.0%
   0.0%  1.73Ki [Mach-O Headers]        1.83Ki   0.0%
   0.0%       0 [Unmapped]                 704   0.0%
   0.0%     688 __DATA,__nl_symbol_ptr     688   0.0%
   0.0%     676 Indirect Symbol Table      676   0.0%
   0.0%     498 __TEXT,__symbol_stub1      498   0.0%
   0.0%      79 [__DATA]                    63   0.0%
 100.0%  34.8Mi TOTAL                   34.7Mi 100.0%
% go version
go version devel +023dbb188d Tue Sep 11 20:28:15 2018 +0000 darwin/amd64

[agnivade]

The general issue for 1.11 size increase is #27266. Maybe close this and add your findings to that ? That issue already has some good context.

[davecheney]

I’d prefer to keep this issue open as it identifies that the increase comes directly from the gopclintab segment.

[bcmills]

Closing as a duplicate of #27266. (The attribution to gopclntab is already mentioned there too.)

[agnivade]

Really closing now :)