This was originally
Revert "cmd/link: fix up debug_range for dsymutil (revert CL 72371)"
which has the effect of no longer using Base Address Selection
Entries in DWARF. However, the build-time costs of that are
about 2%, so instead the hacky fixup that generated technically
incorrect DWARF was removed from the linker, and the choice
is instead made in the compiler, dependent on platform, but
also under control of a flag so that we can report this bug
against LLDB/dsymutil/dwarfdump (really, the LLVM dwarf
libraries).
This however does not solve #31188; debugging still fails,
but dwarfdump no longer complains. There are at least two
LLDB bugs involved, and this change will at allow us
to report them without them being rejected because our
now-obsolete workaround for the first bug creates
not-quite-DWARF.
Updates #31188.
Change-Id: I5300c51ad202147bab7333329ebe961623d2b47d
Reviewed-on: https://go-review.googlesource.com/c/go/+/170638
Run-TryBot: David Chase <drchase@google.com>
Reviewed-by: Heschi Kreinick <heschi@google.com>
Dsymutil, an utility used on macOS when externally linking executables,
does not support base address selector entries in debug_ranges.
To work around this deficiency this commit removes base address
selectors from debug_ranges and emits instead a list composed only of
compile unit relative addresses.
A new type of relocation is introduced, R_ADDRCUOFF, similar to
R_ADDROFF, that relocates an address to its offset from the low_pc of
the symbol's compile unit.
Fixes#21945
Change-Id: Ie991f9bc1afda2b49ac5d734eb41c37d3a37e554
Reviewed-on: https://go-review.googlesource.com/72371
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Heschi Kreinick <heschi@google.com>
Change compiler and linker to emit DWARF lexical blocks in .debug_info
section when compiling with -N -l.
Version of debug_info is updated from DWARF v2 to DWARF v3 since
version 2 does not allow lexical blocks with discontinuous PC ranges.
Remaining open problems:
- scope information is removed from inlined functions
- variables records do not have DW_AT_start_scope attributes so a
variable will shadow other variables with the same name as soon as its
containing scope begins, even before its declaration.
Updates #6913.
Updates #12899.
Change-Id: Idc6808788512ea20e7e45bcf782453acb416fb49
Reviewed-on: https://go-review.googlesource.com/40095
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Prior to this CL, the compiler and assembler
were sloppy about the LSym.Type for LSyms
containing static data.
The linker then fixed this up, converting
Sxxx and SBSS to SDATA, and SNOPTRBSS to SNOPTRDATA
if it noticed that the symbol had associated data.
It is preferable to just get this right in cmd/compile
and cmd/asm, because it removes an unnecessary traversal
of the symbol table from the linker (see #14624).
Do this by touching up the LSym.Type fixes in
LSym.prepwrite and Link.Globl.
I have confirmed by instrumenting the linker
that the now-eliminated code paths were unreached.
And an additional check in the object file writing code
will help preserve that invariant.
There was a case in the Windows linker,
with internal linking and cgo,
where we were generating SNOPTRBSS symbols with data.
For now, convert those at the site at which they occur
into SNOPTRDATA, just like they were.
Does not pass toolstash-check,
but does generate identical linked binaries.
No compiler performance changes.
Change-Id: I77b071ab103685ff8e042cee9abb864385488872
Reviewed-on: https://go-review.googlesource.com/40864
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>
Now only cmd/asm and cmd/compile depend on cmd/internal/obj. Changing
the assembler backends no longer requires reinstalling cmd/link or
cmd/addr2line.
There's also now one canonical definition of the object file format in
cmd/internal/objabi/doc.go, with a warning to update all three
implementations.
objabi is still something of a grab bag of unrelated code (e.g., flag
and environment variable handling probably belong in a separate "tool"
package), but this is still progress.
Fixes#15165.
Fixes#20026.
Change-Id: Ic4b92fac7d0d35438e0d20c9579aad4085c5534c
Reviewed-on: https://go-review.googlesource.com/40972
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
They do basically the same work.
Setuintxx was only used in a single place,
so eliminate it in favor of WriteInt.
duintxxLSym's alignment rounding was not used in practice;
change it into alignment assertion.
Passes toolstash-check. No compiler performance changes.
Change-Id: I0f7410cf2ccffbdc02ad796eaf973ee6a83074f8
Reviewed-on: https://go-review.googlesource.com/40863
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Given code such as
type T struct {
_ string
}
func f() {
var x = T{"space"}
// ...
}
the compiler rewrote the 'var x' line as
var x T
x._ = "space"
The compiler then rejected the assignment to
a blank field, thus rejecting valid code.
It also failed to catch a number of invalid assignments.
And there were insufficient checks for validity
when emitting static data, leading to ICEs.
To fix, check earlier for explicit blanks field names,
explicitly handle legit blanks in sinit,
and don't try to emit static data for nodes
for which typechecking has failed.
Fixes#19482
Change-Id: I594476171d15e6e8ecc6a1749e3859157fe2c929
Reviewed-on: https://go-review.googlesource.com/38006
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This reverts commit c8b889cc4824f4dbd64a51a3f7b5b6dce4b87ed2.
Reason for revert: broke noopt build, compiler performance regression, new Curfn uses
Let's fix those and then try this again.
Change-Id: Icc3cad1365d04cac8fd09da9dbb0bbf55c13ef44
Reviewed-on: https://go-review.googlesource.com/39991
Reviewed-by: Robert Griesemer <gri@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Change compiler and linker to emit DWARF lexical blocks in debug_info.
Version of debug_info is updated from DWARF v.2 to DWARF v.3 since version 2
does not allow lexical blocks with discontinuous ranges.
Second attempt at https://go-review.googlesource.com/#/c/29591/
Remaining open problems:
- scope information is removed from inlined functions
- variables in debug_info do not have DW_AT_start_scope attributes so a
variable will shadow other variables with the same name as soon as its
containing scope begins, before its declaration.
Updates golang/go#12899, golang/go#6913
Change-Id: I0e260a45b564d14a87b88974eb16c5387cb410a5
Reviewed-on: https://go-review.googlesource.com/36879
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Introduce R_WEAKADDROFF, a "weak" variation of the R_ADDROFF relocation
that will only reference the type described if it is in some other way
reachable.
Use this for the ptrToThis field in reflect type information where it
is safe to do so (that is, types that don't need to be included for
interface satisfaction, and types that won't cause the compiler to
recursively generate an endless series of ptr-to-ptr-to-ptr-to...
types).
Also fix a small bug in reflect, where StructOf was not clearing the
ptrToThis field of new types.
Fixes#17931
Change-Id: I4d3b53cb9c916c97b3b16e367794eee142247281
Reviewed-on: https://go-review.googlesource.com/33427
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Fixes#16911.
Fix obsolete inferno-os links, since code.google.com shutdown.
This CL points to the right files by replacing
http://code.google.com/p/inferno-os/source/browse
with
https://bitbucket.org/inferno-os/inferno-os/src/default
To implement the change I wrote and ran this script in the root:
$ grep -Rn 'http://code.google.com/p/inferno-os/source/browse' * \
| cut -d":" -f1 | while read F;do perl -pi -e \
's/http:\/\/code.google.com\/p\/inferno-os\/source\/browse/https:\/\/bitbucket.org\/inferno-os\/inferno-os\/src\/default/g'
$F;done
I excluded any cmd/vendor changes from the commit.
Change-Id: Iaaf828ac8f6fc949019fd01832989d00b29b6749
Reviewed-on: https://go-review.googlesource.com/27994
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
By replacing the *string used to represent pkgPath with a
reflect.name everywhere, the embedded *string for package paths
inside the reflect.name can be replaced by an offset, nameOff.
This reduces the number of pointers in the type information.
This also moves all reflect.name types into the same section, making
it possible to use nameOff more widely in later CLs.
No significant binary size change for normal binaries, but:
linux/amd64 PIE:
cmd/go: -440KB (3.7%)
jujud: -2.6MB (3.2%)
For #6853.
Change-Id: I3890b132a784a1090b1b72b32febfe0bea77eaee
Reviewed-on: https://go-review.googlesource.com/21395
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This is the first in a series of CLs to replace the use of pointers
in binary read-only data with offsets.
In standard Go binaries these CLs have a small effect, shrinking
8-byte pointers to 4-bytes. In position-independent code, it also
saves the dynamic relocation for the pointer. This has a significant
effect on the binary size when building as PIE, c-archive, or
c-shared.
darwin/amd64:
cmd/go: -12KB (0.1%)
jujud: -82KB (0.1%)
linux/amd64 PIE:
cmd/go: -86KB (0.7%)
jujud: -569KB (0.7%)
For #6853.
Change-Id: Iad5625bbeba58dabfd4d334dbee3fcbfe04b2dcf
Reviewed-on: https://go-review.googlesource.com/21284
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Information about CPU architectures (e.g., name, family, byte
ordering, pointer and register size) is currently redundantly
scattered around the source tree. Instead consolidate the basic
information into a single new package cmd/internal/sys.
Also, introduce new sys.I386, sys.AMD64, etc. names for the constants
'8', '6', etc. and replace most uses of the latter. The notable
exceptions are a couple of error messages that still refer to the old
char-based toolchain names and function reltype in cmd/link.
Passes toolstash/buildall.
Change-Id: I8a6f0cbd49577ec1672a98addebc45f767e36461
Reviewed-on: https://go-review.googlesource.com/21623
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
The only remaining place that generated ADATA
Prog was the assembler. Stop, and delete some
now-dead code.
Passes toolstash -cmp.
Change-Id: I26578ff1b4868e98562b44f69d909c083e96f8d5
Reviewed-on: https://go-review.googlesource.com/20646
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Instead of generating ADATA instructions for
static data, write that static data directly
into the linker sym.
This is considerably more efficient.
The assembler still generates
ADATA instructions, so the ADATA machinery
cannot be dismantled yet. (Future work.)
Skipping ADATA has a significant impact
compiling the unicode package, which has lots
of static data.
name old time/op new time/op delta
Unicode 227ms ±10% 192ms ± 4% -15.61% (p=0.000 n=29+30)
name old alloc/op new alloc/op delta
Unicode 51.0MB ± 0% 45.8MB ± 0% -10.29% (p=0.000 n=30+30)
name old allocs/op new allocs/op delta
Unicode 610k ± 0% 578k ± 0% -5.29% (p=0.000 n=30+30)
This does not pass toolstash -cmp, because
this changes the order in which some relocations
get added, and thus it changes the output from
the compiler. It is not worth the execution time
to sort the relocs in the normal case.
However, compiling with -S -v generates identical
output if (1) you suppress printing of ADATA progs
in flushplist and (2) you suppress printing of
cpu timing. It is reasonable to suppress printing
the ADATA progs, since the data itself is dumped
later. I am therefore fairly confident that all
changes are superficial and non-functional.
Fixes#14786, although there's more to do
in general.
Change-Id: I8dfabe7b423b31a30e516cfdf005b62a2e9ccd82
Reviewed-on: https://go-review.googlesource.com/20645
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
No immediate reduction in the size of Addr.
Passes toolstash -cmp.
Change-Id: I78ea4c6e181b6e571ce70a5f1ae8158844eb197d
Reviewed-on: https://go-review.googlesource.com/20276
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Following on from CL 14350, remove the remaining dead code from data.go.
Also leave a TODO to be addressed later (with a unit test) to reduce
the overhead of SymGrow.
Change-Id: Iebad775b1280b54b89e87a3a073ca8af19a8bfba
Reviewed-on: https://go-review.googlesource.com/14359
Run-TryBot: Dave Cheney <dave@cheney.net>
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Also simplifies some silliness around making the .tbss section wrt internal
vs external linking. The "make TLS make sense" project has quite a few more
steps to go.
Issue #11270
Change-Id: Ia4fa135cb22d916728ead95bdbc0ebc1ae06f05c
Reviewed-on: https://go-review.googlesource.com/13990
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
A quick pass through link.go, mostly removing fields that are not
used on the "creating a single object file" side of the fence.
Change-Id: I35ba41378c2c418f7df2f2f88dce65bc64a1a45d
Reviewed-on: https://go-review.googlesource.com/7672
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
An interface{} is more in the spirit of the original union.
By my calculations, on 64-bit systems this reduces
Addr from 120 to 80 bytes, and Prog from 592 to 424 bytes.
Change-Id: I0d7b0981513c2a3c94c9ac76bb4f8816485b5a3c
Reviewed-on: https://go-review.googlesource.com/7744
Reviewed-by: Rob Pike <r@golang.org>
Each architecture had its own Dconv (operand printer) but the syntax is
close to uniform and the code overlap was considerable. Consolidate these
into a single top-level function. A similar but smaller unification is done
for Mconv ("Name" formatter) as well.
The signature is changed. The flag was unused so drop it. Add a
function argument, Rconv, that must be supplied by the caller.
TODO: A future change will unify Rconv as well and this argument
will go away.
Some formats changed, because of the automatic consistency
created by unification. For instance, 0(R1) always prints as (R1)
now, and foo+0(SB) is just foo(SB). Before, some made these
simplifications and some didn't; now they all do.
Update the asm tests that depend on the format.
Change-Id: I6e3310bc19814c0c784ff0b960a154521acd9532
Reviewed-on: https://go-review.googlesource.com/5920
Reviewed-by: Russ Cox <rsc@golang.org>
Ran rsc.io/grind rev 6f0e601 on the source files.
The cleanups move var declarations as close to the use
as possible, splitting disjoint uses of the var into separate
variables. They also remove dead code (especially in
func sudoaddable), which helps with the var moving.
There's more cleanup to come, but this alone cuts the
time spent compiling html/template on my 2013 MacBook Pro
from 3.1 seconds to 2.3 seconds.
Change-Id: I4de499f47b1dd47a560c310bbcde6b08d425cfd6
Reviewed-on: https://go-review.googlesource.com/5637
Reviewed-by: Rob Pike <r@golang.org>
Reconvert using rsc.io/c2go rev 27b3f59.
Changes to converter:
- fatal does not return, so no fallthrough after fatal in switch
- many more function results and variables identified as bool
- simplification of negated boolean expressions
Change-Id: I3bc67da5e46cb7ee613e230cf7e9533036cc870b
Reviewed-on: https://go-review.googlesource.com/5171
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
First draft of converted Go compiler, using rsc.io/c2go rev 83d795a.
Change-Id: I29f4c7010de07d2ff1947bbca9865879d83c32c3
Reviewed-on: https://go-review.googlesource.com/4851
Reviewed-by: Rob Pike <r@golang.org>
cmd/internal/obj reconverted using rsc.io/c2go rev 2a95256.
- Brings in new, more regular Prog, Addr definitions
- Add Prog* argument to oclass in liblink/asm[68].c, for c2go conversion.
- Update objwriter for change in TEXT size encoding.
- Merge 5a, 6a, 8a, 9a changes into new5a, new6a, new8a, new9a (by hand).
- Add +build ignore to cmd/asm/internal/{addr,arch,asm}, cmd/asm.
They need to be updated for the changes.
- Reenable verifyAsm in cmd/go.
- Reenable GOOBJ=2 mode by default in liblink.
All architectures build successfully again.
Change-Id: I2c845c5d365aa484b570476898171bee657b626d
Reviewed-on: https://go-review.googlesource.com/3963
Reviewed-by: Rob Pike <r@golang.org>
For new assembler, reconvert using rsc.io/c2go rev f9db76e.
- Removes trailing _ from Go keywords that are exported.
- Export regstr as Register, anames[5689] as Anames.
Also update clients.
Change-Id: I41c8fd2d14490236f548b4aa0ed0b9bd7571d2d7
Reviewed-on: https://go-review.googlesource.com/3151
Reviewed-by: Rob Pike <r@golang.org>
This CL adds the real cmd/internal/obj packages.
Collectively they correspond to the liblink library.
The conversion was done using rsc.io/c2go's run script
at rsc.io/c2go repo version 706fac7.
This is not the final conversion, just the first working draft.
There will be more updates, but this works well enough
to use with go tool objwriter and pass all.bash.
Change-Id: I9359e835425f995a392bb2fcdbebf29511477bed
Reviewed-on: https://go-review.googlesource.com/3046
Reviewed-by: Ian Lance Taylor <iant@golang.org>
