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path: root/src/runtime/type.go
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2021-05-10cmd/compile,reflect: allow longer type namesKeith Randall
Encode the length of type names and tags in a varint encoding instead of a fixed 2-byte encoding. This allows lengths longer than 65535 (which can happen for large unnamed structs). Removed the alignment check for #14962, it isn't relevant any more since we're no longer reading pointers directly out of this data (it is encoded as an offset which is copied out bytewise). Fixes #44155 Update #14962 Change-Id: I6084f6027e5955dc16777c87b0dd5ea2baa49629 Reviewed-on: https://go-review.googlesource.com/c/go/+/318249 Trust: Keith Randall <khr@golang.org> Run-TryBot: Keith Randall <khr@golang.org> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
2021-03-24cmd/compile, cmd/link: use weak reference in itabCherry Zhang
When converting a type T to a non-empty interface I, we build the itab which contains the code pointers of the methods. Currently, this brings those methods live (if the itab is live), even if the interface method is never used. This CL changes the itab to use weak references, so the methods can be pruned if not otherwise live. Fixes #42421. Change-Id: Iee5de2ba11d603c5a102a2ba60440d839a7f9702 Reviewed-on: https://go-review.googlesource.com/c/go/+/268479 Trust: Cherry Zhang <cherryyz@google.com> Run-TryBot: Cherry Zhang <cherryyz@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Than McIntosh <thanm@google.com>
2021-01-16[dev.regabi] cmd/compile, runtime: fix up comments/error messages from ↵Dan Scales
recent renames Went in a semi-automated way through the clearest renames of functions, and updated comments and error messages where it made sense. Change-Id: Ied8e152b562b705da7f52f715991a77dab60da35 Reviewed-on: https://go-review.googlesource.com/c/go/+/284216 Trust: Dan Scales <danscales@google.com> Run-TryBot: Dan Scales <danscales@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2020-10-28Revert "cmd/compile: split exported/non-exported methods for interface type"Cuong Manh Le
This reverts commit 8f26b57f9afc238bdecb9b7030bc2f4364093885. Reason for revert: break a bunch of code, include standard library. Fixes #42123 Change-Id: Ife90ecbafd2cb395623d1db555fbfc9c1b0098e0 Reviewed-on: https://go-review.googlesource.com/c/go/+/264026 Trust: Cuong Manh Le <cuong.manhle.vn@gmail.com> Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Russ Cox <rsc@golang.org>
2020-10-09cmd/compile: split exported/non-exported methods for interface typeCuong Manh Le
Currently, mhdr/methods is emitted with the same len/cap. There's no way to distinguish between exported and non-exported methods statically. This CL splits mhdr/methods into two parts, use "len" for number of exported methods, and "cap" for all methods. This fixes the bug in issue #22075, which intends to return the number of exported methods but currently return all methods. Note that with this encoding, we still can access either all/exported-only/non-exported-only methods: mhdr[:cap(mhdr)] // all methods mhdr // exported methods mhdr[len(mhdr):cap(mhdr)] // non-exported methods Thank to Matthew Dempsky (@mdempsky) for suggesting this encoding. Fixes #22075 Change-Id: If662adb03ccff27407d55a5578a0ed05a15e7cdd Reviewed-on: https://go-review.googlesource.com/c/go/+/259237 Trust: Cuong Manh Le <cuong.manhle.vn@gmail.com> Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com> Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2020-09-29cmd/link, runtime: use a sentinel value for unreachable methodCherry Zhang
In the method table, the method's code pointer is stored as an offset from the start of the text section. Currently, for an unreachable method, the offset is left as 0, which resolves to the start of the text section at run time. It is possible that there is valid code there. If an unreachable method is ever reached (due to a compiler or linker bug), the execution will jump to a wrong location but may continue to run for a while, until it fails with a seemingly unrelated error. This CL changes it to use -1 for unreachable method instead. At run time this will resolve to an invalid address, which makes it fail immediately if it is ever reached. Change-Id: Ied6ed7f1833c4f3b991fdf55d8810d70d307b2e6 Reviewed-on: https://go-review.googlesource.com/c/go/+/257203 Trust: Cherry Zhang <cherryyz@google.com> Run-TryBot: Cherry Zhang <cherryyz@google.com> Reviewed-by: Than McIntosh <thanm@google.com>
2019-10-28runtime: fix textOff for multiple text sectionsLynn Boger
If a compilation has multiple text sections, code in textOff must compare the offset argument against the range for each text section to determine which one it is in. The comparison looks like this: if uintptr(off) >= sectaddr && uintptr(off) <= sectaddr+sectlen If the off value being compared is equal to sectaddr+sectlen then it is not within the range of the text section but after it. The comparison should be just '<'. Updates #35207 Change-Id: I114633fd734563d38f4e842dd884c6c239f73c95 Reviewed-on: https://go-review.googlesource.com/c/go/+/203817 Run-TryBot: Lynn Boger <laboger@linux.vnet.ibm.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-10-05runtime: add doc to remind adopting changes to reflectliteCuong Manh Le
Updates #34486 Change-Id: Iec9a5d120013aaa287eccf2999b3f2b831be070e Reviewed-on: https://go-review.googlesource.com/c/go/+/197558 Reviewed-by: Ian Lance Taylor <iant@golang.org>
2019-09-21runtime/type: change fieldalign to use mixedCapstwo
All spelling in source code is "fieldAlign", except this place, so change "fieldalign" to use mixedCaps. Change-Id: Icbd9b9d23d9b4f756174e9a3cc4b25776fd90def GitHub-Last-Rev: 44a4fe140a4a473a234ceb5bd927109cbc35bb30 GitHub-Pull-Request: golang/go#34441 Reviewed-on: https://go-review.googlesource.com/c/go/+/196757 Run-TryBot: Andrew Bonventre <andybons@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
2019-09-03cmd/compile,runtime: generate hash functions only for types which are map keysKeith Randall
Right now we generate hash functions for all types, just in case they are used as map keys. That's a lot of wasted effort and binary size for types which will never be used as a map key. Instead, generate hash functions only for types that we know are map keys. Just doing that is a bit too simple, since maps with an interface type as a key might have to hash any concrete key type that implements that interface. So for that case, implement hashing of such types at runtime (instead of with generated code). It will be slower, but only for maps with interface types as keys, and maybe only a bit slower as the aeshash time probably dominates the dispatch time. Reorg where we keep the equals and hash functions. Move the hash function from the key type to the map type, saving a field in every non-map type. That leaves only one function in the alg structure, so get rid of that and just keep the equal function in the type descriptor itself. cmd/go now has 10 generated hash functions, instead of 504. Makes cmd/go 1.0% smaller. Update #6853. Speed on non-interface keys is unchanged. Speed on interface keys is ~20% slower: name old time/op new time/op delta MapInterfaceString-8 23.0ns ±21% 27.6ns ±14% +20.01% (p=0.002 n=10+10) MapInterfacePtr-8 19.4ns ±16% 23.7ns ± 7% +22.48% (p=0.000 n=10+8) Change-Id: I7c2e42292a46b5d4e288aaec4029bdbb01089263 Reviewed-on: https://go-review.googlesource.com/c/go/+/191198 Run-TryBot: Keith Randall <khr@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Martin Möhrmann <moehrmann@google.com>
2019-04-30all: refer to map elements as elements instead of valuesJosh Bleecher Snyder
The spec carefully and consistently uses "key" and "element" as map terminology. The implementation, not so much. This change attempts to make the implementation consistently hew to the spec's terminology. Beyond consistency, this has the advantage of avoid some confusion and naming collisions, since v and value are very generic and commonly used terms. I believe that I found all everything, but there are a lot of non-obvious places for these to hide, and grepping for them is hard. Hopefully this change changes enough of them that we will start using elem going forward. Any remaining hidden cases can be removed ad hoc as they are discovered. The only externally-facing part of this change is in package reflect, where there is a minor doc change and a function parameter name change. Updates #27167 Change-Id: I2f2d78f16c360dc39007b9966d5c2046a29d3701 Reviewed-on: https://go-review.googlesource.com/c/go/+/174523 Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-03-08all: simplify multiple for loopsDaniel Martí
If a for loop has a simple condition and begins with a simple "if x { break; }"; we can simply add "!x" to the loop's condition. While at it, simplify a few assignments to use the common pattern "x := staticDefault; if cond { x = otherValue(); }". Finally, simplify a couple of var declarations. Change-Id: I413982c6abd32905adc85a9a666cb3819139c19f Reviewed-on: https://go-review.googlesource.com/c/go/+/165342 Run-TryBot: Daniel Martí <mvdan@mvdan.cc> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
2018-12-29runtime: panic on uncomparable map key, even if map is emptyKeith Randall
Reorg map flags a bit so we don't need any extra space for the extra flag. Fixes #23734 Change-Id: I436812156240ae90de53d0943fe1aabf3ea37417 Reviewed-on: https://go-review.googlesource.com/c/155918 Run-TryBot: Keith Randall <khr@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
2018-08-22runtime: replace calls to hasprefix with hasPrefixMartin Möhrmann
The hasprefix function is redundant and can be removed since it has the same implementation as hasPrefix modulo variable names. Fixes #25688 Change-Id: I499cc24a2b5c38d1301718a4e66f555fd138386f Reviewed-on: https://go-review.googlesource.com/115835 Run-TryBot: Martin Möhrmann <moehrmann@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ilya Tocar <ilya.tocar@intel.com>
2018-07-11runtime: don't say "different packages" if they may not be differentIan Lance Taylor
Fix the panic message produced for an interface conversion error to only say "types from different packages" if they are definitely from different packges. If they may be from the same package, say "types from different scopes." Updates #18911 Fixes #26094 Change-Id: I0cea50ba31007d88e70c067b4680009ede69bab9 Reviewed-on: https://go-review.googlesource.com/123395 Reviewed-by: Austin Clements <austin@google.com>
2018-05-08runtime: add js/wasm architectureRichard Musiol
This commit adds the js/wasm architecture to the runtime package. Currently WebAssembly has no support for threads yet, see https://github.com/WebAssembly/design/issues/1073. Because of that, there is no preemption of goroutines and no sysmon goroutine. Design doc: https://docs.google.com/document/d/131vjr4DH6JFnb-blm_uRdaC0_Nv3OUwjEY5qVCxCup4 About WebAssembly assembly files: https://docs.google.com/document/d/1GRmy3rA4DiYtBlX-I1Jr_iHykbX8EixC3Mq0TCYqbKc Updates #18892 Change-Id: I7f12d21b5180500d55ae9fd2f7e926a1731db391 Reviewed-on: https://go-review.googlesource.com/103877 Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Austin Clements <austin@google.com>
2018-05-06runtime: remove hmap field from maptypesMartin Möhrmann
The hmap field in the maptype is only used by the runtime to check the sizes of the hmap structure created by the compiler and runtime agree. Comments are already present about the hmap structure definitions in the compiler and runtime needing to be in sync. Add a test that checks the runtimes hmap size is as expected to detect when the compilers and runtimes hmap sizes diverge instead of checking this at runtime when a map is created. Change-Id: I974945ebfdb66883a896386a17bbcae62a18cf2a Reviewed-on: https://go-review.googlesource.com/91796 Run-TryBot: Martin Möhrmann <moehrmann@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org> Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2018-03-15reflect: sort exported methods firstMatthew Dempsky
By moving exported methods to the front of method lists, filtering down to only the exported methods just needs a count of how many exported methods exist, which the compiler can statically provide. This allows getting rid of the exported method cache. For #22075. Change-Id: I8eeb274563a2940e1347c34d673f843ae2569064 Reviewed-on: https://go-review.googlesource.com/100846 Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-09-05cmd/compile: fix and improve struct field reflect informationMatthew Dempsky
The previous logic was overly complicated, generated suboptimally encoded struct type descriptors, and mishandled embeddings of predeclared universal types. Fixes #21122. Fixes #21353. Fixes #21696. Fixes #21702. Updates #21357. Change-Id: If34761fa6dbe4af2af59dee501e7f30845320376 Reviewed-on: https://go-review.googlesource.com/60410 Run-TryBot: Matthew Dempsky <mdempsky@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: David Crawshaw <crawshaw@golang.org>
2017-05-29runtime: fix file reference in commentsDmitry Savintsev
cmd/compile/internal/ld/decodesym.go is now cmd/link/internal/ld/decodesym.go Change-Id: I16ec5c89aa3507e70676c2b50d70f1fde533a085 Reviewed-on: https://go-review.googlesource.com/44373 Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-04-12plugin: properly handle recursively defined typesTodd Neal
Prevent a crash if the same type in two plugins had a recursive definition, either by referring to a pointer to itself or a map existing with the type as a value type (which creates a recursive definition through the overflow bucket type). Fixes #19258 Change-Id: Iac1cbda4c5b6e8edd5e6859a4d5da3bad539a9c6 Reviewed-on: https://go-review.googlesource.com/40292 Run-TryBot: Todd Neal <todd@tneal.org> Reviewed-by: David Crawshaw <crawshaw@golang.org>
2017-01-25[dev.typealias] cmd/compile, reflect: fix struct field names for embedded ↵Russ Cox
byte, rune 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>
2016-11-01runtime: resolve type offsets using source moduleDavid Crawshaw
The runtime.typeEquals function is used during typelinksinit to determine the canonical set of *_type values to use throughout the runtime. As such, it is run against non-canonical *_type values, that is, types from modules that are duplicates of a type from another module that was loaded earlier in the program life. These non-canonical *_type values sometimes contain pointers. These pointers are pointing to position-independent data, and so they are set by ld.so using dynamic relocations when the module is loaded. As such, the pointer can point to the equivalent memory from a previous module. This means if typesEqual follows a pointer inside a *_type, it can end up at a piece of memory from another module. If it reads a typeOff or nameOff from that memory and attempts to resolve it against the non-canonical *_type from the later module, it will end up with a reference to junk memory. Instead, resolve against the pointer the offset was read from, so the data is valid. Fixes #17709. Should no longer matter after #17724 is resolved in a later Go. Change-Id: Ie88b151a3407d82ac030a97b5b6a19fc781901cb Reviewed-on: https://go-review.googlesource.com/32513 Run-TryBot: David Crawshaw <crawshaw@golang.org> Reviewed-by: Keith Randall <khr@golang.org>
2016-11-01runtime: access modules via a sliceDavid Crawshaw
The introduction of -buildmode=plugin means modules can be added to a Go program while it is running. This means there exists some time while the program is running with the module is on the moduledata linked list, but it has not been initialized to the satisfaction of other parts of the runtime. Notably, the GC. This CL adds a new way of access modules, an activeModules function. It returns a slice of modules that is built in the background and atomically swapped in. The parts of the runtime that need to wait on module initialization can use this slice instead of the linked list. Fixes #17455 Change-Id: I04790fd07e40c7295beb47cea202eb439206d33d Reviewed-on: https://go-review.googlesource.com/32357 Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-10-31runtime: make module typemaps visible to the GCDavid Crawshaw
The map[typeOff]*_type object is created at run time and stored in the moduledata. The moduledata object is marked by the linker as SNOPTRDATA, so the reference is ignored by the GC. Running misc/cgo/testplugin/test.bash with GOGC=1 will eventually collect the typemap and crash. This bug probably comes up in -linkshared binaries in Go 1.7. I don't know why we haven't seen a report about this yet. Fixes #17680 Change-Id: I0e9b5c006010e8edd51d9471651620ba665248d3 Reviewed-on: https://go-review.googlesource.com/32430 TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com> Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-09-21cmd/link: split large elf text sections on ppc64xLynn Boger
Some applications built with Go on ppc64x with external linking can fail to link with relocation truncation errors if the elf text section that is generated is larger than 2^26 bytes and that section contains a call instruction (bl) which calls a function beyond the limit addressable by the 24 bit field in the instruction. This solution consists of generating multiple text sections where each is small enough to allow the GNU linker to resolve the calls by generating long branch code where needed. Other changes were added to handle differences in processing when multiple text sections exist. Some adjustments were required to the computation of a method's address when using the method offset table when there are multiple text sections. The number of possible section headers was increased to allow for up to 128 text sections. A test case was also added. Fixes #15823. Change-Id: If8117b0e0afb058cbc072258425a35aef2363c92 Reviewed-on: https://go-review.googlesource.com/27790 Run-TryBot: Ian Lance Taylor <iant@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-08-26runtime: have typelinksinit work forwardsDavid Crawshaw
For reasons I have forgotten typelinksinit processed modules backwards. (I suspect this was an attempt to process types in the executing binary first.) It does not appear to be necessary, and it is not the order we want when a module can be loaded at an arbitrary point during a program's execution as a plugin. So reverse the order. While here, make it safe to call typelinksinit multiple times. Change-Id: Ie10587c55c8e5efa0542981efb6eb3c12dd59e8c Reviewed-on: https://go-review.googlesource.com/27822 Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-06-28reflect, runtime: optimize Name methodDavid Crawshaw
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>
2016-06-24cmd/compile, etc: use tflag to optimize Name()==""David Crawshaw
Improves JSON decoding benchmark: name old time/op new time/op delta CodeDecoder-8 41.3ms ± 6% 39.8ms ± 1% -3.61% (p=0.000 n=10+10) name old speed new speed delta CodeDecoder-8 47.0MB/s ± 6% 48.7MB/s ± 1% +3.66% (p=0.000 n=10+10) Change-Id: I524ee05c432fad5252e79b29222ec635c1dee4b4 Reviewed-on: https://go-review.googlesource.com/24452 Reviewed-by: Ian Lance Taylor <iant@golang.org> Run-TryBot: Ian Lance Taylor <iant@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-06-23cmd/compile, etc: bring back ptrToThisDavid Crawshaw
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>
2016-06-14cmd/compile, etc: handle many struct fieldsDavid Crawshaw
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>
2016-05-26runtime: tell race detector about reflectOffs.lockDavid Crawshaw
Fixes #15832 Change-Id: I6f3f45e3c21edd0e093ecb1d8a067907863478f5 Reviewed-on: https://go-review.googlesource.com/23441 Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
2016-04-27reflect: unnamed interface types have no nameDavid Crawshaw
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>
2016-04-22cmd/compile, etc: use nameOff in uncommonTypeDavid Crawshaw
linux/amd64 PIE: cmd/go: -62KB (0.5%) jujud: -550KB (0.7%) For #6853. Change-Id: Ieb67982abce5832e24b997506f0ae7108f747108 Reviewed-on: https://go-review.googlesource.com/22371 Run-TryBot: David Crawshaw <crawshaw@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-04-22cmd/compile, etc: use nameOff for rtype stringDavid Crawshaw
linux/amd64: cmd/go: -8KB (basically nothing) linux/amd64 PIE: cmd/go: -191KB (1.6%) jujud: -1.5MB (1.9%) Updates #6853 Fixes #15064 Change-Id: I0adbb95685e28be92e8548741df0e11daa0a9b5f Reviewed-on: https://go-review.googlesource.com/21777 Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-04-18cmd/compile, etc: use name offset in method tablesDavid Crawshaw
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>
2016-04-13cmd/compile, etc: use name for type pkgPathDavid Crawshaw
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>
2016-04-13cmd/compile, etc: store method tables as offsetsDavid Crawshaw
This CL introduces the typeOff type and a lookup method of the same name that can turn a typeOff offset into an *rtype. In a typical Go binary (built with buildmode=exe, pie, c-archive, or c-shared), there is one moduledata and all typeOff values are offsets relative to firstmoduledata.types. This makes computing the pointer cheap in typical programs. With buildmode=shared (and one day, buildmode=plugin) there are multiple modules whose relative offset is determined at runtime. We identify a type in the general case by the pair of the original *rtype that references it and its typeOff value. We determine the module from the original pointer, and then use the typeOff from there to compute the final *rtype. To ensure there is only one *rtype representing each type, the runtime initializes a typemap for each module, using any identical type from an earlier module when resolving that offset. This means that types computed from an offset match the type mapped by the pointer dynamic relocations. A series of followup CLs will replace other *rtype values with typeOff (and name/*string with nameOff). For types created at runtime by reflect, type offsets are treated as global IDs and reference into a reflect offset map kept by the runtime. darwin/amd64: cmd/go: -57KB (0.6%) jujud: -557KB (0.8%) linux/amd64 PIE: cmd/go: -361KB (3.0%) jujud: -3.5MB (4.2%) For #6853. Change-Id: Icf096fd884a0a0cb9f280f46f7a26c70a9006c96 Reviewed-on: https://go-review.googlesource.com/21285 Reviewed-by: Ian Lance Taylor <iant@golang.org> Run-TryBot: David Crawshaw <crawshaw@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-03-25cmd/compile, runtime: new static name encodingDavid Crawshaw
Create a byte encoding designed for static Go names. It is intended to be a compact representation of a name and optional tag data that can be turned into a Go string without allocating, and describes whether or not it is exported without unicode table. The encoding is described in reflect/type.go: // The first byte is a bit field containing: // // 1<<0 the name is exported // 1<<1 tag data follows the name // 1<<2 pkgPath *string follow the name and tag // // The next two bytes are the data length: // // l := uint16(data[1])<<8 | uint16(data[2]) // // Bytes [3:3+l] are the string data. // // If tag data follows then bytes 3+l and 3+l+1 are the tag length, // with the data following. // // If the import path follows, then ptrSize bytes at the end of // the data form a *string. The import path is only set for concrete // methods that are defined in a different package than their type. Shrinks binary sizes: cmd/go: 164KB (1.6%) jujud: 1.0MB (1.5%) For #6853. Change-Id: I46b6591015b17936a443c9efb5009de8dfe8b609 Reviewed-on: https://go-review.googlesource.com/20968 Run-TryBot: David Crawshaw <crawshaw@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-03-15cmd/compile: compute second method type at runtimeDavid Crawshaw
The type information for a method includes two variants: a func without the receiver, and a func with the receiver as the first parameter. The former is used as part of the dynamic interface checks, but the latter is only returned as a type in the reflect.Method struct. Instead of computing it at compile time, construct it at run time with reflect.FuncOf. Using cl/20701 as a baseline, cmd/go: -480KB, (4.4%) jujud: -5.6MB, (7.8%) For #6853. Change-Id: I1b8c73f3ab894735f53d00cb9c0b506d84d54e92 Reviewed-on: https://go-review.googlesource.com/20709 Run-TryBot: David Crawshaw <crawshaw@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-03-09cmd/compile: remove slices from rtype.funcTypeDavid Crawshaw
Alternative to golang.org/cl/19852. This memory layout doesn't have an easy type representation, but it is noticeably smaller than the current funcType, and saves significant extra space. Some notes on the layout are in reflect/type.go: // A *rtype for each in and out parameter is stored in an array that // directly follows the funcType (and possibly its uncommonType). So // a function type with one method, one input, and one output is: // // struct { // funcType // uncommonType // [2]*rtype // [0] is in, [1] is out // uncommonTypeSliceContents // } There are three arbitrary limits introduced by this CL: 1. No more than 65535 function input parameters. 2. No more than 32767 function output parameters. 3. reflect.FuncOf is limited to 128 parameters. I don't think these are limits in practice, but are worth noting. Reduces godoc binary size by 2.4%, 330KB. For #6853. Change-Id: I225c0a0516ebdbe92d41dfdf43f716da42dfe347 Reviewed-on: https://go-review.googlesource.com/19916 Reviewed-by: Russ Cox <rsc@golang.org> Run-TryBot: David Crawshaw <crawshaw@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-03-08cmd/compile: remove rtype *uncommonType fieldDavid Crawshaw
Instead of a pointer on every rtype, use a bit flag to indicate that the contents of uncommonType directly follows the rtype value when it is needed. This requires a bit of juggling in the compiler's rtype encoder. The backing arrays for fields in the rtype are presently encoded directly after the slice header. This packing requires separating the encoding of the uncommonType slice headers from their backing arrays. Reduces binary size of godoc by ~180KB (1.5%). No measurable change in all.bash time. For #6853. Change-Id: I60205948ceb5c0abba76fdf619652da9c465a597 Reviewed-on: https://go-review.googlesource.com/19790 Reviewed-by: Russ Cox <rsc@golang.org> Run-TryBot: David Crawshaw <crawshaw@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-03-04reflect: recognize unnamed directional channelsDavid Crawshaw
go test github.com/onsi/gomega/gbytes now passes at tip, and tests added to the reflect package. Fixes #14645 Change-Id: I16216c1a86211a1103d913237fe6bca5000cf885 Reviewed-on: https://go-review.googlesource.com/20221 Run-TryBot: David Crawshaw <crawshaw@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-02-26cmd/compile: remove uncommonType.nameDavid Crawshaw
Reduces binary size of cmd/go by 0.5%. For #6853. Change-Id: I5a4b814049580ab5098ad252d979f80b70d8a5f9 Reviewed-on: https://go-review.googlesource.com/19694 Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org> Run-TryBot: David Crawshaw <crawshaw@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-02-25cmd/compile: remove rtype.ptrToThisDavid Crawshaw
Simplifies some code as ptrToThis was unreliable under dynamic linking. Now the same type lookup is used regardless of execution mode. A synthetic relocation, R_USETYPE, is introduced to make sure the linker includes *T on use of T, if *T is carrying methods. Changes the heap dump format. Anything reading the format needs to look at the last bool of a type of an interface value to determine if the type should be the pointer-to type. Reduces binary size of cmd/go by 0.2%. For #6853. Change-Id: I79fcb19a97402bdb0193f3c7f6d94ddf061ee7b2 Reviewed-on: https://go-review.googlesource.com/19695 Reviewed-by: Keith Randall <khr@golang.org> Run-TryBot: David Crawshaw <crawshaw@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-02-24cmd/compile: embed type string header in rtypeDavid Crawshaw
Reduces binary size of cmd/go by 1%. For #6853. Change-Id: I6f2992a4dd3699db1b532ab08683e82741b9c2e4 Reviewed-on: https://go-review.googlesource.com/19692 Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org> Run-TryBot: David Crawshaw <crawshaw@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-02-23Revert "cmd/compile: move hiter, hmap, and scase definitions into builtin.go"Matthew Dempsky
This reverts commit f28bbb776a050cc3edca2bbe1241d81217a7a251. Change-Id: I82fb81dcff3ddcaefef72949f1ef3a41bcd22301 Reviewed-on: https://go-review.googlesource.com/19849 Run-TryBot: Matthew Dempsky <mdempsky@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Keith Randall <khr@golang.org>
2016-02-22cmd/compile: move hiter, hmap, and scase definitions into builtin.goMatthew Dempsky
Also eliminates per-maptype hiter and hmap types, since they're not really needed anyway. Update packages reflect and runtime accordingly. Reduces golang.org/x/tools/cmd/godoc's text segment by ~170kB: text data bss dec hex filename 13085702 140640 151520 13377862 cc2146 godoc.before 12915382 140640 151520 13207542 c987f6 godoc.after Updates #6853. Change-Id: I948b2bc1f22d477c1756204996b4e3e1fb568d81 Reviewed-on: https://go-review.googlesource.com/16610 Reviewed-by: Keith Randall <khr@golang.org>
2015-11-10cmd/cgo, runtime: add checks for passing pointers from Go to CIan Lance Taylor
This implements part of the proposal in issue 12416 by adding dynamic checks for passing pointers from Go to C. This code is intended to be on at all times. It does not try to catch every case. It does not implement checks on calling Go functions from C. The new cgo checks may be disabled using GODEBUG=cgocheck=0. Update #12416. Change-Id: I48de130e7e2e83fb99a1e176b2c856be38a4d3c8 Reviewed-on: https://go-review.googlesource.com/16003 Reviewed-by: Russ Cox <rsc@golang.org>
2015-10-21runtime: change functype's in and out fields to []*_typeMatthew Dempsky
Allows removing a few gratuitous unsafe.Pointer conversions and parallels the type of reflect.funcType's in and out fields ([]*rtype). Change-Id: Ie5ca230a94407301a854dfd8782a3180d5054bc4 Reviewed-on: https://go-review.googlesource.com/16163 Run-TryBot: Matthew Dempsky <mdempsky@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>