The method Method expects index to be an index of exported fields,
but, before this change, the index used by MethodByName could
take into account unexported fields if those happened sort
before the exported one.
Fixes#21177
Change-Id: I90bb64a47b23e2e43fdd2b8a1e0a2c9a8a63ded2
Reviewed-on: https://go-review.googlesource.com/51810
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
pkgPath always received the empty string. Worse yet, it panicked if it
received anything else. This has been the case ever since newName was
introduced in early 2016.
Change-Id: I5f164305bd30c34455ef35e776c7616f303b37e4
Reviewed-on: https://go-review.googlesource.com/54331
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
When StructOf is used with an anonymous field that has methods, and
that anonymous field is not the first field, the methods we generate
are incorrect because they do not offset to the field as required.
If we encounter that case, panic rather than doing the wrong thing.
Fixes#20824
Updates #15924
Change-Id: I3b0901ddbc6d58af5f7e84660b5e3085a431035d
Reviewed-on: https://go-review.googlesource.com/47035
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
According to the language spec, a struct field name should
be an identifier.
identifier = letter { letter | unicode_digit } .
letter = unicode_letter | "_" .
Implements a function 'isValidFieldName(fieldName string) bool'.
To check if the field name is a valid identifier or not.
It will panic if the field name is invalid.
It uses the non-exported function implementation 'isLetter'
from the package 'scanner', used to parse an identifier.
Fixes#20600.
Change-Id: I1db7db1ad88cab5dbea6565be15cc7461cc56c44
Reviewed-on: https://go-review.googlesource.com/45590
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
We do a division by the elem type size to check if the array size would
be too large for the virtual address space. This is a silly check if the
size is 0, but the problem is that it means a division by zero and a
panic.
Since arrays of empty structs are valid in a regular program, make them
also work in reflect.
Use a separate, explicit test with struct{}{} to make sure the test for
a zero-sized type is not confused with the rest.
Fixes#20313.
Change-Id: I47b8b87e6541631280b79227bdea6a0f6035c9e0
Reviewed-on: https://go-review.googlesource.com/43131
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
When constructing a new type for an array type in ArrayOf, we don't
reset tflag to 0. All the other methods in the package, such as SliceOf,
do this already. This results in the new array type having weird issues
when being printed, such as having tflagExtraStar set when it shouldn't.
That flag removes the first char to get rid of '*', but when used
incorrectly in this case it eats the '[' character leading to broken
strings like "3]int".
This was fixed in 56752eb2 for issue #16722, but ArrayOf was missed.
Also make the XM test struct have a non-zero size as that leads to a
division by zero panic in ArrayOf.
Fixes#20311.
Change-Id: I18f1027fdbe9f71767201e7424269c3ceeb23eb5
Reviewed-on: https://go-review.googlesource.com/43130
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This CL adds a simple explanation about what means the ptrdata field of
the reflect.rtype type.
Also document that rtype needs to be kept in sync with the runtime._type
type that rtype mirrors.
Change-Id: Icd9663a2e4bb94d922a2417cfe4537861d2ccc97
Reviewed-on: https://go-review.googlesource.com/40917
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
The gcdata field only records ptrdata entries, not size entries.
Also fix an obsolete comment: the enforced limit on pointer maps is
now 2048 bytes, not 16 bytes.
I wasn't able to contruct a test case for this. It would require
building a type whose size is greater than 64 bytes but less than 128
bytes, with at least one pointer in first 64 bytes but no pointers
after the first 64 bytes, such that the linker arranges for the one
byte gcbits value to be immediately followed by a non-zero byte.
Change-Id: I9118d3e4ec6f07fd18b72f621c1e5f4fdfe5f80b
Reviewed-on: https://go-review.googlesource.com/37142
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Otherwise, calling PtrTo on the result will fail.
Fixes#19003
Change-Id: I8d7d1981a5d0417d5aee52740469d71e90734963
Reviewed-on: https://go-review.googlesource.com/36731
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
Will also fix type aliases.
Fixes#17766.
For #18130.
Change-Id: I9e1584d47128782152e06abd0a30ef423d5c30d2
Reviewed-on: https://go-review.googlesource.com/35732
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
The runtime internal structField interprets name=="" as meaning anonymous,
but the exported reflect.StructField has always set Name, even for anonymous
fields, and also set Anonymous=true.
The initial implementation of StructOf confused the internal and public
meanings of the StructField, expecting the runtime representation of
anonymous fields instead of the exported reflect API representation.
It also did not document this fact, so that users had no way to know how
to create an anonymous field.
This CL changes StructOf to use the previously documented interpretation
of reflect.StructField instead of an undocumented one.
The implementation of StructOf also, in some cases, allowed creating
structs with unexported fields (if you knew how to ask) but set the
PkgPath incorrectly on those fields. Rather than try to fix that, this CL
changes StructOf to reject attempts to create unexported fields.
(I think that may be the right design choice, not just a temporary limitation.
In any event, it's not the topic for today's work.)
For #17766.
Fixes#18780.
Change-Id: I585a4e324dc5a90551f49d21ae04d2de9ea04b6c
Reviewed-on: https://go-review.googlesource.com/35731
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
Sigh, forgot to run `git mail`.
Change-Id: Idc49be2bb20d6f0e392cb472a63267ffee2ca22c
Reviewed-on: https://go-review.googlesource.com/33476
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.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>
It's possible for the pkgPath of a field to be different than that of
the struct type as a whole. In that case, store the field's pkgPath in
the name field. Use the field's pkgPath when setting PkgPath and when
checking for type identity.
Fixes#17952.
Change-Id: Iebaf92f0054b11427c8f6e4158c3bebcfff06f45
Reviewed-on: https://go-review.googlesource.com/33333
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
An unexported field of a struct is not visible outside of the package
that defines it, so the package path is implicitly part of the
definition of any struct with an unexported field.
Change-Id: I17c6aac822bd0c24188ab8ba1cc406d6b5d82771
Reviewed-on: https://go-review.googlesource.com/32820
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This was supposed to be in CL 31354
but was dropped due to a Git usage error.
For #16573.
Change-Id: I3d99087c8efc8cbc016c55e8365d0005f79d1b2f
Reviewed-on: https://go-review.googlesource.com/31461
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Use terms like "equal" and "identical types" to match the Go spec,
rather than inventing a new explanation. See also discussion on
golang.org/cl/27170.
Updates #16348.
Change-Id: I0fe0bd01c0d1da3c8937a579c2ba44cf1eb16b71
Reviewed-on: https://go-review.googlesource.com/28054
Reviewed-by: Rob Pike <r@golang.org>
The only previous mention of this property was in the String() method.
Since this is the only way to uniquely identify a type and we can't
change this property without breaking the Go 1 guarantee, it seems
better to document this property than hiding it on a method.
Fixes#16348
Change-Id: I3d25f7d6e6007e3c15c2e13010869888d0181fc2
Reviewed-on: https://go-review.googlesource.com/27170
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The reflect package was returning a non-empty PkgPath for an unnamed
type with methods, such as a type whose methods have a pointer
receiver.
Fixes#16328.
Change-Id: I733e93981ebb5c5c108ef9b03bf5494930b93cf3
Reviewed-on: https://go-review.googlesource.com/24862
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Several minor changes that remove a good chunk of the overhead added
to the reflect Name method over the 1.7 cycle, as seen from the
non-SSA architectures.
In particular, there are ~20 fewer instructions in reflect.name.name
on 386, and the method now qualifies for inlining.
The simple JSON decoding benchmark on darwin/386:
name old time/op new time/op delta
CodeDecoder-8 49.2ms ± 0% 48.9ms ± 1% -0.77% (p=0.000 n=10+9)
name old speed new speed delta
CodeDecoder-8 39.4MB/s ± 0% 39.7MB/s ± 1% +0.77% (p=0.000 n=10+9)
On darwin/amd64 the effect is less pronounced:
name old time/op new time/op delta
CodeDecoder-8 38.9ms ± 0% 38.7ms ± 1% -0.38% (p=0.005 n=10+10)
name old speed new speed delta
CodeDecoder-8 49.9MB/s ± 0% 50.1MB/s ± 1% +0.38% (p=0.006 n=10+10)
Counterintuitively, I get much more useful benchmark data out of my
MacBook Pro than a linux workstation with more expensive Intel chips.
While the laptop has fewer cores and an active GUI, the single-threaded
performance is significantly better (nearly 1.5x decoding throughput)
so the differences are more pronounced.
For #16117.
Change-Id: I4e0cc1cc2d271d47d5127b1ee1ca926faf34cabf
Reviewed-on: https://go-review.googlesource.com/24510
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The encoding/json package uses NumMethod()==0 as a fast check for
interface satisfaction. In the case when a type has no methods at
all, we don't need to grab the RWMutex.
Improves JSON decoding benchmark on linux/amd64:
name old time/op new time/op delta
CodeDecoder-8 44.2ms ± 2% 40.6ms ± 1% -8.11% (p=0.000 n=10+10)
name old speed new speed delta
CodeDecoder-8 43.9MB/s ± 2% 47.8MB/s ± 1% +8.82% (p=0.000 n=10+10)
For #16117
Change-Id: Id717e7fcd2f41b7d51d50c26ac167af45bae3747
Reviewed-on: https://go-review.googlesource.com/24433
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This was removed in CL 19695 but it slows down reflect.New, which ends
up on the hot path of things like JSON decoding.
There is no immediate cost in binary size, but it will make it harder to
further shrink run time type information in Go 1.8.
Before
BenchmarkNew-40 30000000 36.3 ns/op
After
BenchmarkNew-40 50000000 29.5 ns/op
Fixes#16161
Updates #16117
Change-Id: If7cb7f3e745d44678f3f5cf3a5338c59847529d2
Reviewed-on: https://go-review.googlesource.com/24400
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This adds 8 bytes of binary size to every type that has methods. It is
the smallest change I could come up with for 1.7.
Fixes#16037
Change-Id: Ibe15c3165854a21768596967757864b880dbfeed
Reviewed-on: https://go-review.googlesource.com/24070
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This CL documents that StructOf currently does not generate wrapper
methods for embedded fields.
Updates #15924
Change-Id: I932011b1491d68767709559f515f699c04ce70d4
Reviewed-on: https://go-review.googlesource.com/23681
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Also remove some of the now unnecessary corner case handling and
tests I've been adding recently for unexported method data.
For #15673
Change-Id: Ie0c7b03f2370bbe8508cdc5be765028f08000bd7
Reviewed-on: https://go-review.googlesource.com/23410
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
The initial implementation of reflect.StructOf in
https://golang.org/cl/9251 had a limitation that field names had to be
ASCII, which was later lifted by https://golang.org/cl/21777. Remove
the out-of-date documentation disallowing UTF-8 field names.
Updates: #5748
Updates: #15064
Change-Id: I2c5bfea46bfd682449c6e847fc972a1a131f51b7
Reviewed-on: https://go-review.googlesource.com/23170
Reviewed-by: David Crawshaw <crawshaw@golang.org>
By picking up a spurious tFlagExtraStar, the method type was printing
as unc instead of func.
Updates #15673
Change-Id: I0c2c189b99bdd4caeb393693be7520b8e3f342bf
Reviewed-on: https://go-review.googlesource.com/23103
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
The new type was inheriting the tflagExtraStar from its prototype.
Fixes#15467
Change-Id: Ic22c2a55cee7580cb59228d52b97e1c0a1e60220
Reviewed-on: https://go-review.googlesource.com/22501
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Fixes#15468
Change-Id: I8723171f87774a98d5e80e7832ebb96dd1fbea74
Reviewed-on: https://go-review.googlesource.com/22524
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
Introduce and start using nameOff for two encoded names. This pair
of changes is best done together because the linker's method decoder
expects the method layouts to match.
Precursor to converting all existing name and *string fields to
nameOff.
linux/amd64:
cmd/go: -45KB (0.5%)
jujud: -389KB (0.6%)
linux/amd64 PIE:
cmd/go: -170KB (1.4%)
jujud: -1.5MB (1.8%)
For #6853.
Change-Id: Ia044423f010fb987ce070b94c46a16fc78666ff6
Reviewed-on: https://go-review.googlesource.com/21396
Reviewed-by: Ian Lance Taylor <iant@golang.org>
cmd and runtime were handled separately, and I'm intentionally skipped
syscall. This is the rest of the standard library.
CL generated mechanically with github.com/mdempsky/unconvert.
Change-Id: I9e0eff886974dedc37adb93f602064b83e469122
Reviewed-on: https://go-review.googlesource.com/22104
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
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>
