A package file may begin as either "package foo" or
"package foo safe". The latter is relevant when using -u.
https://golang.org/cl/6903059 resulted in the distinction
being dropped when a package was read for the second or later time.
This CL records whether that "safe" tag was present,
and includes it in the dummy statement generated for the lexer.
R=golang-dev, r, minux.ma, daniel.morsing, iant
CC=golang-dev
https://golang.org/cl/8255044
A new comment directive //go:noescape instructs the compiler
that the following external (no body) func declaration should be
treated as if none of its arguments escape to the heap.
Fixes#4099.
R=golang-dev, dave, minux.ma, daniel.morsing, remyoudompheng, adg, agl, iant
CC=golang-dev
https://golang.org/cl/7289048
sse2 is a more precise description of the requirement,
and it matches what people will see in, for example
grep sse2 /proc/cpuinfo # linux
sysctl hw.optional.sse2 # os x
R=golang-dev, dsymonds, iant
CC=golang-dev
https://golang.org/cl/7057050
There's no b in race detector.
The new flag matches the one in the go command
(go test -race math).
R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/7072043
This CL adds a flag parser that matches the semantics of Go's
package flag. It also changes the linkers and compilers to use
the new flag parser.
Command lines that used to work, like
8c -FVw
6c -Dfoo
5g -I/foo/bar
now need to be split into separate arguments:
8c -F -V -w
6c -D foo
5g -I /foo/bar
The new spacing will work with both old and new tools.
The new parser also allows = for arguments, as in
6c -D=foo
5g -I=/foo/bar
but that syntax will not work with the old tools.
In addition to matching standard Go binary flag parsing,
the new flag parser generates more detailed usage messages
and opens the door to long flag names.
The recently added gc flag -= has been renamed -complete.
R=remyoudompheng, daniel.morsing, minux.ma, iant
CC=golang-dev
https://golang.org/cl/7035043
A new environment variable GO386 is introduced to choose between
code generation targeting 387 or SSE2. No auto-detection is
performed and the setting defaults to 387 to preserve previous
behaviour.
The patch is a reorganization of CL6549052 by rsc.
Fixes#3912.
R=minux.ma, rsc
CC=golang-dev
https://golang.org/cl/6962043
An error during the compilation can be more precise
than an error at link time.
For 'func init', the error happens always: you can't forward
declare an init func because the name gets mangled.
For other funcs, the error happens only with the special
(and never used by hand) -= flag, which tells 6g the
package is pure go.
The go command now passes -= for pure Go packages.
Fixes#3705.
R=ken2
CC=golang-dev
https://golang.org/cl/6996054
remove zerostack compiler experiment; will do at link time instead
««« original CL description
cmd/gc: add GOEXPERIMENT=zerostack to clear stack on function entry
This is expensive but it might be useful in cases where
people are suffering from false positives during garbage
collection and are willing to trade the CPU time for getting
rid of the false positives.
On the other hand it only eliminates false positives caused
by other function calls, not false positives caused by dead
temporaries stored in the current function call.
The 5g/6g/8g changes were pulled out of the history, from
the last time we needed to do this (to work around a goto bug).
The code in go.h, lex.c, pgen.c is new but tiny.
R=ken2
CC=golang-dev
https://golang.org/cl/6938073
»»»
R=ken2
CC=golang-dev
https://golang.org/cl/7002051
This is expensive but it might be useful in cases where
people are suffering from false positives during garbage
collection and are willing to trade the CPU time for getting
rid of the false positives.
On the other hand it only eliminates false positives caused
by other function calls, not false positives caused by dead
temporaries stored in the current function call.
The 5g/6g/8g changes were pulled out of the history, from
the last time we needed to do this (to work around a goto bug).
The code in go.h, lex.c, pgen.c is new but tiny.
R=ken2
CC=golang-dev
https://golang.org/cl/6938073
The code inside the casee and casep labels can perfectly be merged since
they essentially do the same. The character to be stored where cp points is
just the character contained by the c variable.
R=golang-dev, dave, rsc
CC=golang-dev
https://golang.org/cl/6845112
Check the return value from malloc - do not assume that we were
allocated memory just because we asked for it.
Update #4415.
R=minux.ma, daniel.morsing, remyoudompheng, rsc
CC=golang-dev
https://golang.org/cl/6782100
In order to add these, we need to be able to find references
to such types that already exist in the binary. To do that, introduce
a new linker section holding a list of the types corresponding to
arrays, chans, maps, and slices.
To offset the storage cost of this list, and to simplify the code,
remove the interface{} header from the representation of a
runtime type. It was used in early versions of the code but was
made obsolete by the kind field: a switch on kind is more efficient
than a type switch.
In the godoc binary, removing the interface{} header cuts two
words from each of about 10,000 types. Adding back the list of pointers
to array, chan, map, and slice types reintroduces one word for
each of about 500 types. On a 64-bit machine, then, this CL *removes*
a net 156 kB of read-only data from the binary.
This CL does not include the needed support for precise garbage
collection. I have created issue 4375 to track that.
This CL also does not set the 'algorithm' - specifically the equality
and copy functions - for a new array correctly, so I have unexported
ArrayOf for now. That is also part of issue 4375.
Fixes#2339.
R=r, remyoudompheng, mirtchovski, iant
CC=golang-dev
https://golang.org/cl/6572043
This is an experiment in static analysis of Go programs
to understand which struct fields a program might use.
It is not part of the Go language specification, it must
be enabled explicitly when building the toolchain,
and it may be removed at any time.
After building the toolchain with GOEXPERIMENT=fieldtrack,
a specific field can be marked for tracking by including
`go:"track"` in the field tag:
package pkg
type T struct {
F int `go:"track"`
G int // untracked
}
To simplify usage, only named struct types can have
tracked fields, and only exported fields can be tracked.
The implementation works by making each function begin
with a sequence of no-op USEFIELD instructions declaring
which tracked fields are accessed by a specific function.
After the linker's dead code elimination removes unused
functions, the fields referred to by the remaining
USEFIELD instructions are the ones reported as used by
the binary.
The -k option to the linker specifies the fully qualified
symbol name (such as my/pkg.list) of a string variable that
should be initialized with the field tracking information
for the program. The field tracking string is a sequence
of lines, each terminated by a \n and describing a single
tracked field referred to by the program. Each line is made
up of one or more tab-separated fields. The first field is
the name of the tracked field, fully qualified, as in
"my/pkg.T.F". Subsequent fields give a shortest path of
reverse references from that field to a global variable or
function, corresponding to one way in which the program
might reach that field.
A common source of false positives in field tracking is
types with large method sets, because a reference to the
type descriptor carries with it references to all methods.
To address this problem, the CL also introduces a comment
annotation
//go:nointerface
that marks an upcoming method declaration as unavailable
for use in satisfying interfaces, both statically and
dynamically. Such a method is also invisible to package
reflect.
Again, all of this is disabled by default. It only turns on
if you have GOEXPERIMENT=fieldtrack set during make.bash.
R=iant, ken
CC=golang-dev
https://golang.org/cl/6749064
This is the first part of a bigger change that adds data race detection feature:
https://golang.org/cl/6456044
This change makes gc compiler instrument memory accesses when supplied with -b flag.
R=rsc, nigeltao, lvd
CC=golang-dev
https://golang.org/cl/6497074
This fixes a problem with ELF tools thinking they know the
format of the symbol table, as we do not use any of the
standard formats for that table.
This change will probably annoy the Plan 9 users, but I
believe there are other incompatibilities already that mean
they have to use a Go-specific nm.
Fixes#3473.
R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/6500117
There may be further savings if convT2I can avoid the function call
if the cache is good and T is uintptr-shaped, a la convT2E, but that
will be a follow-up CL.
src/pkg/runtime:
benchmark old ns/op new ns/op delta
BenchmarkConvT2ISmall 43 15 -64.01%
BenchmarkConvT2IUintptr 45 14 -67.48%
BenchmarkConvT2ILarge 130 101 -22.31%
test/bench/go1:
benchmark old ns/op new ns/op delta
BenchmarkBinaryTree17 8588997000 8499058000 -1.05%
BenchmarkFannkuch11 5300392000 5358093000 +1.09%
BenchmarkGobDecode 30295580 31040190 +2.46%
BenchmarkGobEncode 18102070 17675650 -2.36%
BenchmarkGzip 774191400 771591400 -0.34%
BenchmarkGunzip 245915100 247464100 +0.63%
BenchmarkJSONEncode 123577000 121423050 -1.74%
BenchmarkJSONDecode 451969800 596256200 +31.92%
BenchmarkMandelbrot200 10060050 10072880 +0.13%
BenchmarkParse 10989840 11037710 +0.44%
BenchmarkRevcomp 1782666000 1716864000 -3.69%
BenchmarkTemplate 798286600 723234400 -9.40%
R=rsc, bradfitz, go.peter.90, daniel.morsing, dave, uriel
CC=golang-dev
https://golang.org/cl/6337058
CL 4313064 fixed its test case but did not address a
general enough problem:
type T1 struct { F *T2 }
type T2 T1
type T3 T2
could still end up copying the definition of T1 for T2
before T1 was done being evaluated, or T3 before T2
was done.
In order to propagate the updates correctly,
record a copy of an incomplete type for re-execution
once the type is completed. Roll back CL 4313064.
Fixes#3709.
R=ken2
CC=golang-dev, lstoakes
https://golang.org/cl/6301059
The original implementation of closures created the
underlying top-level function during walk, which is fairly
late in the compilation process and caused ordering-based
complications due to earlier stages that had to be repeated
any number of times.
Create the underlying function during typecheck, much
earlier, so that later stages can be run just once.
The result is a simpler compilation sequence.
R=ken2
CC=golang-dev
https://golang.org/cl/6279049
I tried before to make relative imports work by simply
invoking the compiler in the right directory, so that
an import of ./foo could be resolved by ./foo.a.
This required creating a separate tree of package binaries
that included the full path to the source directory, so that
/home/gopher/bar.go would be compiled in
tmpdir/work/local/home/gopher and perhaps find
a ./foo.a in that directory.
This model breaks on Windows because : appears in path
names but cannot be used in subdirectory names, and I
missed one or two places where it needed to be removed.
The model breaks more fundamentally when compiling
a test of a package that lives outside the Go path, because
we effectively use a ./ import in the generated testmain,
but there we want to be able to resolve the ./ import
of the test package to one directory and all the other ./
imports to a different directory. Piggybacking on the compiler's
current working directory is then no longer possible.
Instead, introduce a new compiler option -D prefix that
makes the compiler turn a ./ import into prefix+that,
so that import "./foo" with -D a/b/c turns into import
"a/b/c/foo". Then we can invent a package hierarchy
"_/" with subdirectories named for file system paths:
import "./foo" in the directory /home/gopher becomes
import "_/home/gopher/foo", and since that final path
is just an ordinary import now, all the ordinary processing
works, without special cases.
We will have to change the name of the hierarchy if we
ever decide to introduce a standard package with import
path "_", but that seems unlikely, and the detail is known
only in temporary packages that get thrown away at the
end of a build.
Fixes#3169.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/5732045
They are broken and hard to make work.
They have never worked: if you import "/tmp/x"
from "/home/rsc/p.c" then the compiler rewrites
this into import "/home/rsc/tmp/x", which is
clearly wrong.
Also we just disallowed the : character in import
paths, so import "c:/foo" is already not allowed.
Finally, in order to support absolute paths well in
a build tool we'd have to provide a mechanism to
instruct the compiler to resolve absolute imports
by looking in some other tree (where the binaries live)
and provide a mapping from absolute path to location
in that tree. This CL avoids adding that complexity.
This is not part of the language spec (and should not be),
so no spec change is needed.
If we need to make them work later, we can.
R=ken2
CC=golang-dev
https://golang.org/cl/5712043
Also allow multiple invalid import statements in a
single file.
Fixes#3021. The changes to go/parser and the
language specifcation have already been committed.
R=rsc, gri
CC=golang-dev
https://golang.org/cl/5672084
This is a manual undo of CL 5674098.
It does not implement the even less strict spec
that we just agreed on, but it gets us back where
we were at the last weekly.
R=ken2
CC=golang-dev
https://golang.org/cl/5683069
unsafe: delete Typeof, Reflect, Unreflect, New, NewArray
Part of issue 2955 and issue 2968.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/5650069
The change to -m is the only one necessary
to close the issue. The others are useful
to know about when debugging but shouldn't
be in the usage message since they may go
away or change at any time.
Fixes#2802.
R=lvd, rsc
CC=golang-dev
https://golang.org/cl/5606046
flag -l means: inlining on, -ll inline with early typecheck
-l lazily typechecks imports on use and re-export, nicer for debugging
-lm produces output suitable for errchk tests, repeated -mm... increases inl.c's verbosity
export processed constants, instead of originals
outparams get ->inlvar too, and initialized to zero
fix shared rlist bug, that lead to typecheck messing up the patched tree
properly handle non-method calls to methods T.meth(t, a...)
removed embryonic code to handle closures in inlined bodies
also inline calls inside closures (todo: move from phase 6b to 4)
Fixes#2579.
R=rsc
CC=golang-dev
https://golang.org/cl/5489106
Cross- and intra package inlining of single assignments or return <expression>.
Minus some hairy cases, currently including other calls, expressions with closures and ... arguments.
R=rsc, rogpeppe, adg, gri
CC=golang-dev
https://golang.org/cl/5400043
