valgrind complained that under some circumstances,
*nr = *nc
was being called when nr and nc were the same *Node. The suggestion my Rémy was to introduce a tmp node to avoid the potential for aliasing in subnode.
R=remyoudompheng, minux.ma, rsc
CC=golang-dev
https://golang.org/cl/7780044
Method calls on interfaces with large stored values
will call the pointer receiver method which may be
a wrapper over a method with value receiver.
This is particularly inefficient for very small bodies.
Inlining the wrapped method body saves a potentially expensive
function call.
benchmark old ns/op new ns/op delta
BenchmarkSortString1K 802295 641387 -20.06%
BenchmarkSortInt1K 359914 238234 -33.81%
BenchmarkSortInt64K 35764226 22803078 -36.24%
Fixes#4707.
R=golang-dev, daniel.morsing, rsc
CC=golang-dev
https://golang.org/cl/7214044
If all locals are optimized away, the type instructions would stay in the instruction stream. Call fixautoused to scrub the output.
Fixes#4915.
R=rsc
CC=golang-dev
https://golang.org/cl/7385055
Composite literals using the &T{} form were incorrectly
exported, leading to weird errors at import time.
Fixes#4879.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/7395054
This avoids an allocation when closures are used
as "macros", in Walk idioms, or as argument to defer.
benchmark old ns/op new ns/op delta
BenchmarkSearchWrappers 1171 354 -69.77%
BenchmarkCallClosure 3 3 -12.54%
BenchmarkCallClosure1 119 7 -93.95%
BenchmarkCallClosure2 183 74 -59.18%
BenchmarkCallClosure3 187 75 -59.57%
BenchmarkCallClosure4 187 76 -58.98%
Compared to Go 1:
benchmark old ns/op new ns/op delta
BenchmarkSearchWrappers 3208 354 -88.97%
Fixes#3520.
R=daniel.morsing, bradfitz, minux.ma, dave, rsc
CC=golang-dev
https://golang.org/cl/7397056
Now that the type information is in TYPE instructions
that are not rewritten by the optimization passes,
we don't have to try to preserve the type information
(no longer) attached to MOV instructions.
R=ken2
CC=golang-dev
https://golang.org/cl/7402054
The type information is (and for years has been) included
as an extra field in the address chunk of an instruction.
Unfortunately, suppose there is a string at a+24(FP) and
we have an instruction reading its length. It will say:
MOVQ x+32(FP), AX
and the type of *that* argument is int (not slice), because
it is the length being read. This confuses the picture seen
by debuggers and now, worse, by the garbage collector.
Instead of attaching the type information to all uses,
emit an explicit list of TYPE instructions with the information.
The TYPE instructions are no-ops whose only role is to
provide an address to attach type information to.
For example, this function:
func f(x, y, z int) (a, b string) {
return
}
now compiles into:
--- prog list "f" ---
0000 (/Users/rsc/x.go:3) TEXT f+0(SB),$0-56
0001 (/Users/rsc/x.go:3) LOCALS ,
0002 (/Users/rsc/x.go:3) TYPE x+0(FP){int},$8
0003 (/Users/rsc/x.go:3) TYPE y+8(FP){int},$8
0004 (/Users/rsc/x.go:3) TYPE z+16(FP){int},$8
0005 (/Users/rsc/x.go:3) TYPE a+24(FP){string},$16
0006 (/Users/rsc/x.go:3) TYPE b+40(FP){string},$16
0007 (/Users/rsc/x.go:3) MOVQ $0,b+40(FP)
0008 (/Users/rsc/x.go:3) MOVQ $0,b+48(FP)
0009 (/Users/rsc/x.go:3) MOVQ $0,a+24(FP)
0010 (/Users/rsc/x.go:3) MOVQ $0,a+32(FP)
0011 (/Users/rsc/x.go:4) RET ,
The { } show the formerly hidden type information.
The { } syntax is used when printing from within the gc compiler.
It is not accepted by the assemblers.
The same type information is now included on global variables:
0055 (/Users/rsc/x.go:15) GLOBL slice+0(SB){[]string},$24(AL*0)
This more accurate type information fixes a bug in the
garbage collector's precise heap collection.
The linker only cares about globals right now, but having the
local information should make things a little nicer for Carl
in the future.
Fixes#4907.
R=ken2
CC=golang-dev
https://golang.org/cl/7395056
Change ARM context register to R7, to get out of the way
of the register allocator during the compilation of the
prologue statements (it wants to use R0 as a temporary).
Step 2 of http://golang.org/s/go11func.
R=ken2
CC=golang-dev
https://golang.org/cl/7369048
Previously, the func structure contained an inaccurate value for
the args member and a 0 value for the locals member.
This change populates the func structure with args and locals
values computed by the compiler. The number of args was
already available in the ATEXT instruction. The number of
locals is now passed through in the new ALOCALS instruction.
This change also switches the unit of args and locals to be
bytes, just like the frame member, instead of 32-bit words.
R=golang-dev, bradfitz, cshapiro, dave, rsc
CC=golang-dev
https://golang.org/cl/7399045
Also:
- faster code for example extraction
- simplify handling of command documentation:
all "main" packages are treated as commands
- various minor cleanups along the way
For commands written in Go, any doc.go file containing
documentation must now be part of package main (rather
then package documentation), otherwise the documentation
won't show up in godoc (it will still build, though).
For commands written in C, documentation may still be
in doc.go files defining package documentation, but the
recommended way is to explicitly ignore those files with
a +build ignore constraint to define package main.
Fixes#4806.
R=adg, rsc, dave, bradfitz
CC=golang-dev
https://golang.org/cl/7333046
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
If the analysis reached a node twice, then the analysis was cut off.
However, if the second arrival is at a lower depth (closer to escaping)
then it is important to repeat the traversal.
The repeating must be cut off at some point to avoid the occasional
infinite recursion. This CL cuts it off as soon as possible while still
passing all tests.
Fixes#4751.
R=ken2
CC=golang-dev, lvd
https://golang.org/cl/7303043
Was not re-walking the new AND node, so that its ullman
count was wrong, so that the code generator attempted to
store values in registers across the call.
Fixes#4752.
R=ken2
CC=golang-dev
https://golang.org/cl/7288054
* Avoid treating CALL fn(SB) as justification for introducing
and tracking a registerized variable for fn(SB).
* Remove USED(n) after declaration and zeroing of n.
It was left over from when the compiler emitted more
aggressive set and not used errors, and it was keeping
the optimizer from removing a redundant zeroing of n
when n was a pointer or integer variable.
Update #597.
R=ken2
CC=golang-dev
https://golang.org/cl/7277048
Those symbols are only allowed during imports;
the parser may expect them but saying that doesn't help users.
Fixes#3434.
R=ken2
CC=golang-dev
https://golang.org/cl/7277045
For consistency with conversions that look like function calls,
conversions that don't look like function calls now allow an
optional trailing comma.
That is, int(x,) has always been syntactically valid.
Now []int(x,) is valid too.
Fixes#4162.
R=ken2
CC=golang-dev
https://golang.org/cl/7288045
Expressions involving nil, even if they can be evaluated
at compile time, do not count as Go constants and cannot
be used in const initializers.
Fixes#4673.
Fixes#4680.
R=ken2
CC=golang-dev
https://golang.org/cl/7278043
Export data was broken after revision 6b602ab487d6
when -l is specified at least 3 times: it makes the compiler
write out func (*T).Method() declarations in export data, which
is not supported.
Also fix the formatting of recover() in export data. It was
not treated like panic() and was rendered as "<node RECOVER>".
R=golang-dev, lvd, minux.ma, rsc
CC=golang-dev
https://golang.org/cl/7067051
cmd/8g/gsubr.c: unreachable code
cmd/8g/reg.c: overspecifed class
cmd/dist/plan9.c: unused parameter
cmd/gc/fmt.c: stkdelta is now a vlong
cmd/gc/racewalk.c: used but not set
R=golang-dev, seed, rsc
CC=golang-dev
https://golang.org/cl/7067052
The test case of issue 4585 was not passing due to
miscalculation of memequal args, and the previous fix
does not handle padding at the end of a struct.
Handling of padding at end of structs also fixes the case
of [n]T where T is such a padded struct.
Fixes#4585.
(again)
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/7133059
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
The linker split PKGDEF into (prefix, name, def) pairs,
and defines def to begin after a space following the identifier.
This is totally wrong for the following export data:
func "".FunctionName()
var SomethingCompletelyUnrelated int
The linker would parse
name=`"".FunctionName()\n\tvar`
def=`SomethingCompletelyUnrelated int`
since there is no space after FunctionName.
R=minux.ma, rsc
CC=golang-dev
https://golang.org/cl/7068051
A constant node of type uintptr with a nil literal could
happen in two cases: []int(nil)[1:] and
uintptr(unsafe.Pointer(nil)).
Fixes#4614.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/7059043
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
Unnamed types like structs with embedded fields can have methods.
These methods are generated on-the-fly by the compiler and
it may happen for identical types in different packages.
The linker must accept these multiple definitions.
Fixes#4590.
R=golang-dev, rsc
CC=golang-dev, remy
https://golang.org/cl/7030051
Before this CL, defining the variable worked fine, but then when
the implicit package-level init func was created, that caused a
name collision and a confusing error about the redeclaration.
Also add a test for issue 3705 (func init() needs body).
Fixes#4517.
R=ken2
CC=golang-dev
https://golang.org/cl/7008045
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
Ordinary variable load was assumed to be not worth saving,
but not if one of the function calls later might change
its value.
Fixes#4313.
R=ken2
CC=golang-dev
https://golang.org/cl/6997047
The patch makes the compile user an ordinary package-local
symbol for the name of embedded fields of builtin type.
This is incompatible with the fix delivered for issue 2687
(revision 3c060add43fb) but fixes it in a different way, because
the explicit symbol on the field makes the typechecker able to
find it in lookdot.
Fixes#3552.
R=lvd, rsc, daniel.morsing
CC=golang-dev
https://golang.org/cl/6866047
The typechecking code was doing an extra, unnecessary
indirection.
Fixes#4458.
R=golang-dev, daniel.morsing, rsc
CC=golang-dev
https://golang.org/cl/6998051
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
A fatal error used to happen when escassign-ing a multiple
function return to a single node. However, the situation
naturally appears when using "go f(g())" or "defer f(g())",
because g() is escassign-ed to sink.
Fixes#4529.
R=golang-dev, lvd, minux.ma, rsc
CC=golang-dev
https://golang.org/cl/6920060
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:
func main() {
v := make([]int64, 10)
i := 1
_ = v[(i*4)/3]
}
crashes compiler with:
Program received signal SIGSEGV, Segmentation fault.
0x000000000043c274 in walkexpr (np=0x7fffffffc9b8, init=0x0) at src/cmd/gc/walk.c:587
587 *init = concat(*init, n->ninit);
(gdb) bt
#0 0x000000000043c274 in walkexpr (np=0x7fffffffc9b8, init=0x0) at src/cmd/gc/walk.c:587
#1 0x0000000000432d15 in copyexpr (n=0x7ffff7f69a48, t=<optimized out>, init=0x0) at src/cmd/gc/subr.c:2020
#2 0x000000000043f281 in walkdiv (init=0x0, np=0x7fffffffca70) at src/cmd/gc/walk.c:2901
#3 walkexpr (np=0x7ffff7f69760, init=0x0) at src/cmd/gc/walk.c:956
#4 0x000000000043d801 in walkexpr (np=0x7ffff7f69bc0, init=0x0) at src/cmd/gc/walk.c:988
#5 0x000000000043cc9b in walkexpr (np=0x7ffff7f69d38, init=0x0) at src/cmd/gc/walk.c:1068
#6 0x000000000043c50b in walkexpr (np=0x7ffff7f69f50, init=0x0) at src/cmd/gc/walk.c:879
#7 0x000000000043c50b in walkexpr (np=0x7ffff7f6a0c8, init=0x0) at src/cmd/gc/walk.c:879
#8 0x0000000000440a53 in walkexprlist (l=0x7ffff7f6a0c8, init=0x0) at src/cmd/gc/walk.c:357
#9 0x000000000043d0bf in walkexpr (np=0x7fffffffd318, init=0x0) at src/cmd/gc/walk.c:566
#10 0x00000000004402bf in vmkcall (fn=<optimized out>, t=0x0, init=0x0, va=0x7fffffffd368) at src/cmd/gc/walk.c:2275
#11 0x000000000044059a in mkcall (name=<optimized out>, t=0x0, init=0x0) at src/cmd/gc/walk.c:2287
#12 0x000000000042862b in callinstr (np=0x7fffffffd4c8, init=0x7fffffffd568, wr=0, skip=<optimized out>) at src/cmd/gc/racewalk.c:478
#13 0x00000000004288b7 in racewalknode (np=0x7ffff7f68108, init=0x7fffffffd568, wr=0, skip=0) at src/cmd/gc/racewalk.c:287
#14 0x0000000000428781 in racewalknode (np=0x7ffff7f65840, init=0x7fffffffd568, wr=0, skip=0) at src/cmd/gc/racewalk.c:302
#15 0x0000000000428abd in racewalklist (l=0x7ffff7f65840, init=0x0) at src/cmd/gc/racewalk.c:97
#16 0x0000000000428d0b in racewalk (fn=0x7ffff7f5f010) at src/cmd/gc/racewalk.c:63
#17 0x0000000000402b9c in compile (fn=0x7ffff7f5f010) at src/cmd/6g/../gc/pgen.c:67
#18 0x0000000000419f86 in funccompile (n=0x7ffff7f5f010, isclosure=0) at src/cmd/gc/dcl.c:1414
#19 0x0000000000424161 in p9main (argc=<optimized out>, argv=<optimized out>) at src/cmd/gc/lex.c:431
#20 0x0000000000401739 in main (argc=<optimized out>, argv=<optimized out>) at src/lib9/main.c:35
The problem is nil init passed to mkcall().
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6940045
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
This check for BADWIDTH might happen while in defercheckwidth, making it raise errors for non-erroneous situations.
Fixes#4495.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6927043
Used to say:
issue4251.go:12: inverted slice range
issue4251.go:12: constant -1 overflows uint64
issue4251.go:16: inverted slice range
issue4251.go:16: constant -1 overflows uint64
issue4251.go:20: inverted slice range
issue4251.go:20: constant -1 overflows uint64
With this patch, only gives the "inverted slice range" errors.
R=golang-dev, daniel.morsing
CC=golang-dev
https://golang.org/cl/6871058
The compiler was confused when inlining a T.Method(f()) call
where f returns multiple values: support for this was marked
as TODO.
Variadic calls are not supported but are not inlined either.
Add a test preventively for that case.
Fixes#4167.
R=golang-dev, rsc, lvd
CC=golang-dev
https://golang.org/cl/6871043
W/o this change stack traces do not show from where sync.Once()
or atomic.XXX was called.
This change add funcenter/exit instrumentation to sync/sync.atomic
packages.
R=golang-dev
CC=golang-dev
https://golang.org/cl/6854112
This allows 5g and 8g to benefit from the rewrite as shifts
or magic multiplies. The 64-bit arithmetic is not handled there,
and left in 6g.
Update #2230.
R=golang-dev, dave, mtj, iant, rsc
CC=golang-dev
https://golang.org/cl/6819123
Bools from comparisons can be assigned to all bool types, but this idealness would propagate through logical operators when the result should have been lowered to a non-ideal form.
Fixes#3924.
R=golang-dev, remyoudompheng, r, rsc, mtj
CC=golang-dev
https://golang.org/cl/6855061
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
When exporting a body containing
x, ok := v.(Type)
the definition for Type was not being included, so when the body
was actually used, it would cause an "unknown type" compiler error.
Fixes#4370.
R=ken2
CC=golang-dev
https://golang.org/cl/6827064
The code assumed that the only choices were EscNone, EscScope, and EscHeap,
so that it makes sense to set EscScope only if the current setting is EscNone.
Now that we have the many variants of EscReturn, this logic is false, and it was
causing important EscScopes to be ignored in favor of EscReturn.
Fixes#4360.
R=ken2
CC=golang-dev, lvd
https://golang.org/cl/6816103
Avoids problems with local declarations shadowing other names.
We write a more explicit form than the incoming program, so there
may be additional type annotations. For example:
int := "hello"
j := 2
would normally turn into
var int string = "hello"
var j int = 2
but the int variable shadows the int type in the second line.
This CL marks all local variables with a per-function sequence number,
so that this would instead be:
var int·1 string = "hello"
var j·2 int = 2
Fixes#4326.
R=ken2
CC=golang-dev
https://golang.org/cl/6816100
Current racewalk transformation looks like:
x := <-makeChan().c
\/\/\/\/\/\/\/\/\/
runtime.raceread(&makeChan().c)
x := <-makeChan().c
and so makeChan() is called twice.
With this CL the transformation looks like:
x := <-makeChan().c
\/\/\/\/\/\/\/\/\/
chan *tmp = &(makeChan().c)
raceread(&*tmp)
x := <-(*tmp)
Fixes#4245.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6822075
It is refactoring towards generic walk
+ it handles mode nodes.
Partially fixes 4228 issue.
R=golang-dev, lvd, rsc
CC=golang-dev
https://golang.org/cl/6775098
When the first result of a type assertion is blank, the compiler would still copy out a potentially large non-interface type.
Fixes#1021.
R=golang-dev, bradfitz, rsc
CC=golang-dev
https://golang.org/cl/6812079
The test for this is test/index.go, which is not run by
default. That test does not currently pass even after this is
applied, due to issue 4348.
Fixes#4344.
R=golang-dev, daniel.morsing, rsc
CC=golang-dev
https://golang.org/cl/6815085
It happens that blocks are used for function calls in a
quite low-level way so they cannot be instrumented as
usual.
Blocks are also used for inlined functions.
R=golang-dev, rsc, dvyukov
CC=golang-dev
https://golang.org/cl/6821068
Compiling expressions like:
s[s[s[s[s[s[s[s[s[s[s[s[i]]]]]]]]]]]]
make 5g and 6g run out of registers. Such expressions can arise
if a slice is used to represent a permutation and the user wants
to iterate it.
This is due to the usual problem of allocating registers before
going down the expression tree, instead of allocating them in a
postfix way.
The functions cgenr and agenr (that generate a value to a newly
allocated register instead of an existing location), are either
introduced or modified when they already existed to allocate
the new register as late as possible, and sudoaddable is disabled
for OINDEX nodes so that igen/agenr is used instead.
Update #4207.
R=dave, daniel.morsing, rsc
CC=golang-dev
https://golang.org/cl/6733055
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
1. Prepend racefuncenter() to fn->enter -- fn->enter can contain new() calls,
and we want them to be in the scope of the function.
2. Dump fn->enter and fn->exit.
3. Add TODO that OTYPESW expression can contain interesting memory accesses.
4. Ignore only _ names instead of all names starting with _.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6822048
The idea is to (1) process ninit of all nodes,
and (2) put instrumentation of ninit into the nodes themselves (not the top-level statement ninit).
Fixes#4304.
R=golang-dev, rsc
CC=golang-dev, lvd
https://golang.org/cl/6818049
When local declarations needed unexported types, these could
be missing in the export data.
Fixes build with -gcflags -lll, except for exp/gotype.
R=golang-dev, rsc, lvd
CC=golang-dev
https://golang.org/cl/6813067
This should make the compiler emit errors specific to the bounds checking instead of overflow errors on the underlying types.
Updates #4232.
R=rsc
CC=golang-dev
https://golang.org/cl/6783054
Plan 9 and Go's lib9/fmt disagree on whether %#x includes the 0x prefix
when printing 0, because ANSI C gave bad advice long ago.
Avoiding that case makes binaries compiled on different systems compatible.
R=ken2
CC=akumar, golang-dev
https://golang.org/cl/6814066
- make sure dclcontext == PAUTO only in function bodies
- introduce PDISCARD to discard declarations in bodies of repeated imports
- skip printing initializing OAS'es in export mode, assuming they only occur after ODCL's
- remove ODCL and the initializing OAS from inl.c:ishairy
- fix confused use of ->typecheck in typecheckinl: it's about the ->inl, not about the fn.
- debuging aids: print ntype on ONAMEs too and -Emm instead of -Ell.
fixes#2812
R=rsc
CC=golang-dev
https://golang.org/cl/6800043
includes step 0: synthesize outparams, from 6600044
includes step 1,2: give outparams loopdepth 0 and verify unchanged results
generate esc:$mask tags, but still tie to sink if a param has mask != 0
from 6610054
adds final steps:
- have esccall generate n->escretval, a list of nodes the function results flow to
- use these in esccall and ORETURN/OAS2FUNC/and f(g())
- only tie parameters to sink if tag is absent, otherwise according to mask, tie them to escretval
R=rsc, bradfitz
CC=dave, gobot, golang-dev, iant, rsc
https://golang.org/cl/6741044
includes step 0: synthesize outparams, from 6600044
step 1: give outparams loopdepth 0 and verify unchanged results
step 2: generate esc:$mask tags, but still tie to sink if a param has mask != 0
next step: use in esccall (and ORETURN with implicit OAS2FUNC) to avoid tying to sink
R=rsc
CC=golang-dev
https://golang.org/cl/6610054
in typecheck and walk, conversion from OAS2RECV to OAS2
and to OSELRECV2 duplicated the ->rlist->n to ->right
thereby destroying the strict tree-ness of the AST (up to
ONAMES) of course. Several recursions in esc.c and inl.c
and probably elsewhere assume nodes of the tree aren't duplicated.
rather than defensively code around this, i'd rather assert
these cases away and fix their cause.
(this was tripped in 6741044)
R=rsc
CC=golang-dev
https://golang.org/cl/6750043
Someone new to the language may not know the connection between ints and arrays, which was the only thing that the previous error told you anything about.
Fixes#4256.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6739048
Since this patch changes the way complex literals are written
in export data, there are a few other glitches.
Fixes#4159.
R=golang-dev, rsc
CC=golang-dev, remy
https://golang.org/cl/6674047
The compiler is crashing on the following code:
type TypeID int
func (t *TypeID) encodeType(x int) (tt TypeID, err error) {
switch x {
case 0:
return t.encodeType(x * x)
}
return 0, nil
}
The pass marks "return struct" {tt TypeID, err error} as used,
and this causes internal check failure.
I've added the test to:
https://golang.org/cl/6525052/diff/7020/src/pkg/runtime/race/regression_test.go
R=golang-dev, minux.ma, rsc
CC=golang-dev
https://golang.org/cl/6611049
The protection against segfaults does not completely solve
crashes and breaks test/fixedbugs/bug365.go
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6615058
The nil dereference in the next few lines doesn't seem
to cause a segmentation fault on Unix, but does seem
to halt the Go compiler.
The following is a test case:
>>>
package main
func mine(int b) int {
return b + 2
}
func main() {
mine()
c = mine()
}
<<<
Without this change only the following is caught:
typecheck.go:3: undefined: b
typecheck.go:4: undefined: b
with it, we catch all the errors:
typecheck.go:3: undefined: b
typecheck.go:4: undefined: b
typecheck.go:10: undefined: c
typecheck.go:10: cannot assign to c .
R=rsc, minux.ma
CC=golang-dev
https://golang.org/cl/6542060
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
Also mention that ignoring second blank identifier of range is required by the spec in the code.
Fixes#4173.
R=daniel.morsing, remyoudompheng, r
CC=golang-dev
https://golang.org/cl/6594043
Low hanging fruit optimization. Will remove an expensive copy if the range variable is an array.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6564052
Was not handling &x.y[0] and &x.y.z correctly where
y is an array or struct-valued field (not a pointer).
R=ken2
CC=golang-dev
https://golang.org/cl/6551059
This CL makes the compiler understand that the type of
the len or cap of a map, slice, or string is 'int', not 'int32'.
It does not change the meaning of int, but it should make
the eventual change of the meaning of int in 6g a bit smoother.
Update #2188.
R=ken, dave, remyoudompheng
CC=golang-dev
https://golang.org/cl/6542059
During interface compare, the operands will be evaluated twice. The operands might include function calls for conversion, so make them cheap before comparing them.
R=rsc
CC=golang-dev
https://golang.org/cl/6498133
In switches without an expression, the compiler would not convert the implicit true to an interface, causing codegen errors.
Fixes#3980.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6497147
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
Accomplished by synchronizing the formatting of conversion errors between typecheck.c and subr.c
Fixes#3984.
R=golang-dev, remyoudompheng, rsc
CC=golang-dev
https://golang.org/cl/6500064
This fixes a spurious 'invalid recursive type' error, and stops the compiler from emitting errors on uses of the invalid type.
Fixes#3766.
R=golang-dev, dave, minux.ma, rsc
CC=golang-dev
https://golang.org/cl/6443100
The compiler is incorrectly rejecting switches on arrays of
comparable types. It also doesn't catch incomparable structs
when typechecking the switch, leading to unreadable errors
during typechecking of the generated code.
Fixes#3894.
R=rsc
CC=gobot, golang-dev, r, remy
https://golang.org/cl/6442074
The receive operator was given incorrect precedence
resulting in incorrect deletion of parentheses.
Fixes#3843.
R=rsc
CC=golang-dev, remy
https://golang.org/cl/6442049
They were previously ignored when deciding order and
detecting dependency loops.
Fixes#3824.
R=rsc, golang-dev
CC=golang-dev, remy
https://golang.org/cl/6455055
The error was caused by a call to implements() even when
the type switch variable was not an interface.
Fixes#3786.
R=golang-dev, r
CC=golang-dev, remy
https://golang.org/cl/6354102
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
If there are mutually recursive functions, there is a cycle in
the dependency graph, so the order is actually dependency order
among the strongly connected components: mutually recursive
functions get put into the same batch and analyzed together.
(Until now the entire package was put in one batch.)
The non-recursive case (single function, maybe with some
closures inside) will be able to be more precise about inputs
that escape only back to outputs, but that is not implemented yet.
R=ken2
CC=golang-dev, lvd
https://golang.org/cl/6304050
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
Drop expecttaken function in favor of extra argument
to gbranch and bgen. Mark loop condition as likely to
be true, so that loops are generated inline.
The main benefit here is contiguous code when trying
to read the generated assembly. It has only minor effects
on the timing, and they mostly cancel the minor effects
that aligning function entry points had. One exception:
both changes made Fannkuch faster.
Compared to before CL 6244066 (before aligned functions)
benchmark old ns/op new ns/op delta
BenchmarkBinaryTree17 4222117400 4201958800 -0.48%
BenchmarkFannkuch11 3462631800 3215908600 -7.13%
BenchmarkGobDecode 20887622 20899164 +0.06%
BenchmarkGobEncode 9548772 9439083 -1.15%
BenchmarkGzip 151687 152060 +0.25%
BenchmarkGunzip 8742 8711 -0.35%
BenchmarkJSONEncode 62730560 62686700 -0.07%
BenchmarkJSONDecode 252569180 252368960 -0.08%
BenchmarkMandelbrot200 5267599 5252531 -0.29%
BenchmarkRevcomp25M 980813500 985248400 +0.45%
BenchmarkTemplate 361259100 357414680 -1.06%
Compared to tip (aligned functions):
benchmark old ns/op new ns/op delta
BenchmarkBinaryTree17 4140739800 4201958800 +1.48%
BenchmarkFannkuch11 3259914400 3215908600 -1.35%
BenchmarkGobDecode 20620222 20899164 +1.35%
BenchmarkGobEncode 9384886 9439083 +0.58%
BenchmarkGzip 150333 152060 +1.15%
BenchmarkGunzip 8741 8711 -0.34%
BenchmarkJSONEncode 65210990 62686700 -3.87%
BenchmarkJSONDecode 249394860 252368960 +1.19%
BenchmarkMandelbrot200 5273394 5252531 -0.40%
BenchmarkRevcomp25M 996013800 985248400 -1.08%
BenchmarkTemplate 360620840 357414680 -0.89%
R=ken2
CC=golang-dev
https://golang.org/cl/6245069
It's sad to introduce a new macro, but rnd shows up consistently
in profiles, and the function call overwhelms the two arithmetic
instructions it performs.
R=r
CC=golang-dev
https://golang.org/cl/6260051
