delta/go-git.git/src/debug, branch dev.go2go

cmd/link,debug/elf: mips32, add .gnu.attributes and .MIPS.abiflags sections

2021-03-02T00:51:00+00:00

MIPS32 uses .gnu.attributes and .MIPS.abiflags sections to mark FP ABI
the object is using, and the kernel will set the correct FP mode for it.

Currrently Go doesn't generate these 2 sections. If we link object
without these 2 sections togather FPXX objects, the result will be FPXX,
which is wrong:
   FP32 + FPXX -> FP32
   FPXX + FP64 -> FP64
   FP32 + FP64 -> reject

These 2 sections is also needed to support FPXX and FP64 in future.

More details about FP32/FPXX/FP64 are explained in:
    https://web.archive.org/web/20180828210612/https://dmz-portal.mips.com/wiki/MIPS_O32_ABI_-_FR0_and_FR1_Interlinking

Fixes #39677

Change-Id: Ia34e7461dee38a4f575dd8ace609988744512ac1
Reviewed-on: https://go-review.googlesource.com/c/go/+/239217
Run-TryBot: Cherry Zhang 
Reviewed-by: Cherry Zhang 
TryBot-Result: Go Bot 
Trust: Meng Zhuo

all: go fmt std cmd (but revert vendor)

2021-02-20T03:54:50+00:00

Make all our package sources use Go 1.17 gofmt format
(adding //go:build lines).

Part of //go:build change (#41184).
See https://golang.org/design/draft-gobuild

Change-Id: Ia0534360e4957e58cd9a18429c39d0e32a6addb4
Reviewed-on: https://go-review.googlesource.com/c/go/+/294430
Trust: Russ Cox 
Run-TryBot: Russ Cox 
TryBot-Result: Go Bot 
Reviewed-by: Jason A. Donenfeld 
Reviewed-by: Ian Lance Taylor

debug/pe: recognize arm64 executables

2021-02-19T00:40:00+00:00

We still need to add test data, but as yet we haven't identified
a good Windows arm64 compiler to produce small binaries.

This CL is part of a stack adding windows/arm64
support (#36439), intended to land in the Go 1.17 cycle.

Change-Id: Ifbecb9a6e25f7af38e20b7d7830df7f5efe2798a
Reviewed-on: https://go-review.googlesource.com/c/go/+/288820
Trust: Russ Cox 
Trust: Jason A. Donenfeld 
Run-TryBot: Russ Cox 
Reviewed-by: Cherry Zhang 
Reviewed-by: Alex Brainman 
Reviewed-by: Jason A. Donenfeld

debug/dwarf: don't try to parse addr/rnglists header

2020-12-14T18:06:06+00:00

In an executable, the debug_addr and debug_rnglists sections are
assembled by concatenating the input sections, and each input section
has a header, and each header may have different attributes. So just
parsing the single header isn't right.  Parsing the header is not
necessary to handle offsets into these sections which is all we do.

Looking at the header is also problematic because GCC with
-gsplit-dwarf when using DWARF versions 2 through 4 emits a
.debug_addr section, but it has no header.  The header was only added
for DWARF 5. So we can't parse the header at all for that case, and we
can't even detect that case in general.

This CL also fixes SeekPC with addrx and strx formats, by not using
the wrong compilation unit to find the address or string base.
To make that work when parsing the compilation unit itself, we add
support for delay the resolution of those values until we know the base.

New test binaries built with

gcc -gdwarf-5 -no-pie debug/dwarf/testdata/line[12].c
(gcc (Debian 10.2.0-15) 10.2.0)

clang -gdwarf-5 -no-pie debug/dwarf/testdata/line[12].c
(clang version 9.0.1-14)

Change-Id: I66783e0eded629bf80c467767f781164d344a54d
Reviewed-on: https://go-review.googlesource.com/c/go/+/277233
Trust: Ian Lance Taylor 
Reviewed-by: Than McIntosh

all: update to use os.ReadFile, os.WriteFile, os.CreateTemp, os.MkdirTemp

2020-12-09T19:12:23+00:00

As part of #42026, these helpers from io/ioutil were moved to os.
(ioutil.TempFile and TempDir became os.CreateTemp and MkdirTemp.)

Update the Go tree to use the preferred names.

As usual, code compiled with the Go 1.4 bootstrap toolchain
and code vendored from other sources is excluded.

ReadDir changes are in a separate CL, because they are not a
simple search and replace.

For #42026.

Change-Id: If318df0216d57e95ea0c4093b89f65e5b0ababb3
Reviewed-on: https://go-review.googlesource.com/c/go/+/266365
Trust: Russ Cox 
Run-TryBot: Russ Cox 
TryBot-Result: Go Bot 
Reviewed-by: Ian Lance Taylor

cmd/link: emit include directories in DWARF line table prologue

2020-10-30T18:01:54+00:00

This patch changes the way the linker emits the DWARF line table
prologue, specifically the file table. Previously files were left
unmodified, and the directory table was empty. For each compilation
unit we now scan the unit file table and build up a common set of
directories, emit them into the directory table, and then emit file
entries that refer to the dirs. This provides a modest binary size
savings.

For kubernetes kubelet:

$ objdump -h /tmp/kubelet.old | fgrep debug_line
 36 .zdebug_line  019a55f5  0000000000000000  0000000000000000  084a5123  2**0
$ objdump -h /tmp/kubelet.new | fgrep debug_line
 36 .zdebug_line  01146fd2  0000000000000000  0000000000000000  084a510a  2**0

[where the value following the section name above is the section size
in hex, so roughly a 30% decrease in this case.]

The actual savings will depend on the length of the pathnames
involved, so it's hard to really pin down how much savings we'll see
here. In addition, emitting the files this way reduces the
"compressibility" of the line table, so there could even be cases
where we don't win at all.

Updates #6853, #19784, #36495.

Change-Id: I298d8561da5ed3ebc9d38aa772874851baa2f4f4
Reviewed-on: https://go-review.googlesource.com/c/go/+/263017
Run-TryBot: Than McIntosh 
TryBot-Result: Go Bot 
Reviewed-by: Austin Clements 
Trust: Than McIntosh

debug/dwarf: add support for DWARFv5 to (*Data).Ranges

2020-10-24T04:11:41+00:00

Updates the (*Data).Ranges method to work with DWARFv5 which uses the
new debug_rnglists section instead of debug_ranges.

This does not include supporting DW_FORM_rnglistx.

General support for DWARFv5 was added by CL 175138.

Change-Id: I01f919a865616a3ff12f5bf649c2c9abf89fcf52
Reviewed-on: https://go-review.googlesource.com/c/go/+/236657
Run-TryBot: Ian Lance Taylor 
TryBot-Result: Go Bot 
Reviewed-by: Ian Lance Taylor 
Trust: Emmanuel Odeke

all: update references to symbols moved from io/ioutil to io

2020-10-20T18:41:18+00:00

The old ioutil references are still valid, but update our code
to reflect best practices and get used to the new locations.

Code compiled with the bootstrap toolchain
(cmd/asm, cmd/dist, cmd/compile, debug/elf)
must remain Go 1.4-compatible and is excluded.
Also excluded vendored code.

For #41190.

Change-Id: I6d86f2bf7bc37a9d904b6cee3fe0c7af6d94d5b1
Reviewed-on: https://go-review.googlesource.com/c/go/+/263142
Trust: Russ Cox 
Run-TryBot: Russ Cox 
TryBot-Result: Go Bot 
Reviewed-by: Emmanuel Odeke

[dev.link] Merge branch 'master' into dev.link

2020-09-30T22:00:58+00:00

2 conflicts, that make sense.
	src/cmd/internal/obj/objfile.go
	src/cmd/link/internal/loader/loader.go

Change-Id: Ib224e2d248cb568fa1e888af79dd908b2f5e05ff

all: add GOOS=ios

2020-09-23T18:12:59+00:00

Introduce GOOS=ios for iOS systems. GOOS=ios matches "darwin"
build tag, like GOOS=android matches "linux" and GOOS=illumos
matches "solaris". Only ios/arm64 is supported (ios/amd64 is
not).

GOOS=ios and GOOS=darwin remain essentially the same at this
point. They will diverge at later time, to differentiate macOS
and iOS.

Uses of GOOS=="darwin" are changed to (GOOS=="darwin" || GOOS=="ios"),
except if it clearly means macOS (e.g. GOOS=="darwin" && GOARCH=="amd64"),
it remains GOOS=="darwin".

Updates #38485.

Change-Id: I4faacdc1008f42434599efb3c3ad90763a83b67c
Reviewed-on: https://go-review.googlesource.com/c/go/+/254740
Trust: Cherry Zhang 
Run-TryBot: Cherry Zhang 
TryBot-Result: Go Bot 
Reviewed-by: Austin Clements