8 Commits

Author SHA1 Message Date
Alessandro Arzilli
08029be9fc cmd/compile/internal/dwarfgen: refactor putvar and putAbstractVar
Currently, changing putvar or putAbstractVar involves:

1. changing the abbrevs array to add new abbrevs or modify existing ones
2. changing the DW_ABRV_XXX const block to add the new abbrevs, this const
   block must match the changes to the abbrevs array
3. change the code at the start of putvar and putAbstractVar that selects
   the abbrev to use
4. change the body of putvar/putAbstractVar to emit the right attributes in
   the right sequence

Each change must agree with all other, this is error prone and if an mistake
is made there is no compile time or runtime check detecting it. Erroneous
code will simply produce unreadable debug sections.

This commit adds a mechanism to automatically generate code for abbrev
selection as well as the abbrev definitions based on static examination of
the body of putvar and putAbstractVar.

TestPutVarAbbrevGenerator is responsible for checking that the generated
code is kept updated and will regenerated it by passing the '-generate'
option to it.

benchstat output:

                         |    old.txt    |               new.txt                |
                         |    sec/op     |    sec/op      vs base               |
Template                    153.8m ±  6%    153.0m ±  6%       ~ (p=0.853 n=10)
Unicode                     98.98m ± 19%   100.22m ± 15%       ~ (p=0.796 n=10)
GoTypes                    1013.7m ± 13%    943.6m ±  8%       ~ (p=0.353 n=10)
Compiler                    98.48m ± 10%    97.79m ±  6%       ~ (p=0.353 n=10)
SSA                          8.921 ± 31%     6.872 ± 37%       ~ (p=0.912 n=10)
Flate                       114.3m ± 21%    128.0m ± 36%       ~ (p=0.436 n=10)
GoParser                    219.0m ± 27%    214.9m ± 26%       ~ (p=0.631 n=10)
Reflect                     447.5m ± 20%    452.6m ± 22%       ~ (p=0.684 n=10)
Tar                         166.9m ± 27%    166.2m ± 27%       ~ (p=0.529 n=10)
XML                         218.6m ± 25%    219.3m ± 24%       ~ (p=0.631 n=10)
LinkCompiler                492.7m ± 12%    523.2m ± 13%       ~ (p=0.315 n=10)
ExternalLinkCompiler         1.684 ±  3%     1.684 ±  2%       ~ (p=0.684 n=10)
LinkWithoutDebugCompiler    296.0m ±  8%    304.9m ± 12%       ~ (p=0.579 n=10)
StdCmd                       69.59 ± 15%     70.76 ± 14%       ~ (p=0.436 n=10)
geomean                     516.0m          511.5m        -0.87%

                         |   old.txt    |               new.txt               |
                         | user-sec/op  | user-sec/op   vs base               |
Template                   281.5m ± 10%   269.6m ± 13%       ~ (p=0.315 n=10)
Unicode                    107.3m ±  8%   110.2m ±  8%       ~ (p=0.165 n=10)
GoTypes                     2.414 ± 16%    2.181 ±  9%       ~ (p=0.315 n=10)
Compiler                   116.0m ± 16%   119.1m ± 11%       ~ (p=0.971 n=10)
SSA                         25.47 ± 39%    17.75 ± 52%       ~ (p=0.739 n=10)
Flate                      205.2m ± 25%   256.2m ± 43%       ~ (p=0.393 n=10)
GoParser                   456.8m ± 28%   427.0m ± 24%       ~ (p=0.912 n=10)
Reflect                    960.3m ± 22%   990.5m ± 23%       ~ (p=0.280 n=10)
Tar                        299.8m ± 27%   307.9m ± 27%       ~ (p=0.631 n=10)
XML                        425.0m ± 21%   432.8m ± 24%       ~ (p=0.353 n=10)
LinkCompiler               768.1m ± 11%   796.9m ± 14%       ~ (p=0.631 n=10)
ExternalLinkCompiler        1.713 ±  5%    1.666 ±  4%       ~ (p=0.190 n=10)
LinkWithoutDebugCompiler   313.0m ±  9%   316.7m ± 12%       ~ (p=0.481 n=10)
geomean                    588.6m         579.5m        -1.55%

          |   old.txt    |                new.txt                |
          |  text-bytes  |  text-bytes   vs base                 |
HelloSize   842.9Ki ± 0%   842.9Ki ± 0%       ~ (p=1.000 n=10) ¹
CmdGoSize   10.95Mi ± 0%   10.95Mi ± 0%       ~ (p=1.000 n=10) ¹
geomean     3.003Mi        3.003Mi       +0.00%
¹ all samples are equal

          |   old.txt    |                new.txt                |
          |  data-bytes  |  data-bytes   vs base                 |
HelloSize   15.08Ki ± 0%   15.08Ki ± 0%       ~ (p=1.000 n=10) ¹
CmdGoSize   314.7Ki ± 0%   314.7Ki ± 0%       ~ (p=1.000 n=10) ¹
geomean     68.88Ki        68.88Ki       +0.00%
¹ all samples are equal

          |   old.txt    |                new.txt                |
          |  bss-bytes   |  bss-bytes    vs base                 |
HelloSize   396.8Ki ± 0%   396.8Ki ± 0%       ~ (p=1.000 n=10) ¹
CmdGoSize   428.8Ki ± 0%   428.8Ki ± 0%       ~ (p=1.000 n=10) ¹
geomean     412.5Ki        412.5Ki       +0.00%
¹ all samples are equal

          |   old.txt    |               new.txt               |
          |  exe-bytes   |  exe-bytes    vs base               |
HelloSize   1.310Mi ± 0%   1.310Mi ± 0%  -0.01% (p=0.000 n=10)
CmdGoSize   16.37Mi ± 0%   16.37Mi ± 0%  -0.00% (p=0.000 n=10)
geomean     4.631Mi        4.631Mi       -0.00%

Change-Id: I7edf37b5a47fd9aceef931ddf2c701e66a7b38b2
Reviewed-on: https://go-review.googlesource.com/c/go/+/563815
Reviewed-by: Michael Pratt <mpratt@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
Auto-Submit: Michael Pratt <mpratt@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
2024-02-26 20:45:07 +00:00
Matthew Dempsky
661e3be497 cmd/compile/internal/dwarfgen: remove unversion
The unified export data format doesn't rely on embedding version
numbers in local variable names anymore, so there's no need to look
for them.

While here, simplify the checking for "~r" or "~b" to just "~",
because the next commit is going to eliminate "~b", but introduce
"~p".

Change-Id: I3ac73150ee561c66356a0c4aee5290b44a4893ee
Reviewed-on: https://go-review.googlesource.com/c/go/+/527695
Auto-Submit: Matthew Dempsky <mdempsky@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Than McIntosh <thanm@google.com>
2023-09-12 18:52:49 +00:00
Matthew Dempsky
c9bb7ce2d7 cmd/internal/obj: simplify filename handling
The old Go object file format used linker symbols like "gofile..foo"
to record references to the filename "foo". But the current object
file format has a dedicated section for file names, so we don't need
these useless prefixes anymore.

Also, change DWARF generation to pass around the src.Pos directly,
rather than the old file symbols, which it just turned back into a
file index before writing out anyway.

Finally, directly record the FileIndex into src.PosBase, so that we
can skip the map lookups.

Change-Id: Ia4a5ebfa95da271f2522e45befdb9f137c16d373
Reviewed-on: https://go-review.googlesource.com/c/go/+/523378
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Auto-Submit: Matthew Dempsky <mdempsky@google.com>
2023-09-01 15:52:41 +00:00
Matthew Dempsky
eaae2d45c7 cmd: simplify some handling of package paths
We have obj.Link.Pkgpath, so we don't need to pass it redundantly in
places where we already have an *obj.Link.

Also, renaming the parser's "compilingRuntime" field to "allowABI", to
match the "AllowAsmABI" name used by objabi.LookupPkgSpecial.

Finally, push the handling of GOEXPERIMENT_* flags up to cmd/asm's
main entry point, by simply appending them to flags.D.

Change-Id: I6ada134522b0cbc90d35bcb145fbe045338fefb7
Reviewed-on: https://go-review.googlesource.com/c/go/+/523297
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Auto-Submit: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
2023-08-29 07:48:38 +00:00
Michael Pratt
f60a2a9c94 cmd/compile: adjust inlined DW_AT_call_line by //line
insertInlCall mistakenly uses the absolute line number of the call
rather than the relative line number (adjusted by //line). Switch to the
correct line number.

The call filename was already correct.

Fixes #58648

Change-Id: Id8d1848895233e972d8cfe9c5789a88e62d06556
Reviewed-on: https://go-review.googlesource.com/c/go/+/470876
Reviewed-by: Than McIntosh <thanm@google.com>
Run-TryBot: Michael Pratt <mpratt@google.com>
Auto-Submit: Michael Pratt <mpratt@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
2023-02-23 22:08:33 +00:00
Matthew Dempsky
322879d5c9 cmd/compile/internal/dwarfgen: use src.Pos.Rel{Filename,Line,Col} consistently
It appears that this code predates golang.org/cl/96535, which added
RelCol to support /*line*/ directives.

Change-Id: Ib79cebc1be53af706e84e8799eeea81ef8c81c8b
Reviewed-on: https://go-review.googlesource.com/c/go/+/343430
Trust: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
2021-08-18 23:19:19 +00:00
Than McIntosh
e78e04ce39 cmd/compile: fix panic in DWARF-gen handling obfuscated code
DWARF generation uses variable source positions (file/line/col) as a
way to uniquely identify locals and parameters, as part of the process
of matching up post-optimization variables with the corresponding
pre-optimization versions (since the DWARF needs to be in terms of the
original source constructs).

This strategy can run into problems when compiling obfuscated or
machine-generated code, where you can in some circumstances wind up
with two local variables that appear to have the same name, file,
line, and column. This patch changes DWARF generation to skip over
such duplicates as opposed to issuing a fatal error (if an
obfuscation tool is in use, it is unlikely that a human being will be
able to make much sense of DWARF info in any case).

Fixes #44378.

Change-Id: I198022d184701aa9ec3dce42c005d29b72d2e321
Reviewed-on: https://go-review.googlesource.com/c/go/+/294289
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Trust: Than McIntosh <thanm@google.com>
Run-TryBot: Than McIntosh <thanm@google.com>
2021-02-21 02:25:26 +00:00
Russ Cox
01fd2d05c8 [dev.regabi] cmd/compile: split out package dwarfgen [generated]
[git-generate]
cd src/cmd/compile/internal/gc

rf '
	# Inline and remove ngotype.
	ex {
		import "cmd/compile/internal/ir"
		import "cmd/compile/internal/reflectdata"
		var n ir.Node
		ngotype(n) -> reflectdata.TypeSym(n.Type())
	}
	rm ngotype

	mv recordFlags RecordFlags
	mv recordPackageName RecordPackageName
	mv RecordFlags RecordPackageName dwarf.go

	mv debuginfo Info
	mv genAbstractFunc AbstractFunc
	mv scope.go scope_test.go dwarf.go dwinl.go cmd/compile/internal/dwarfgen
'

Change-Id: I31fa982900dbba2066ca4c7a706af922e5481c70
Reviewed-on: https://go-review.googlesource.com/c/go/+/279477
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2020-12-23 06:39:36 +00:00