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path: root/src/cmd/link/internal/ld/deadcode.go
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2025-07-30all: remove redundant Swiss prefixesMichael Pratt
Now that there is only one map implementation we can simplify names. For #54766. Change-Id: I6a6a636cc6a8fc5e7712c27782fc0ced7467b939 Reviewed-on: https://go-review.googlesource.com/c/go/+/691596 Reviewed-by: Keith Randall <khr@google.com> Auto-Submit: Michael Pratt <mpratt@google.com> Reviewed-by: Keith Randall <khr@golang.org> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
2025-07-30all: remove GOEXPERIMENT=swissmapMichael Pratt
For #54766. Change-Id: I6a6a636c40b5fe2e8b0d4a5e23933492bc8bb76e Reviewed-on: https://go-review.googlesource.com/c/go/+/691595 Reviewed-by: Keith Randall <khr@google.com> Auto-Submit: Michael Pratt <mpratt@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Keith Randall <khr@golang.org>
2024-11-17internal/runtime/maps: eliminate a load from the hot pathKeith Randall
typ.Group.Size involves two loads. Instead cache GroupSize as a separate fields of the map type so we can get to it in just one load. Change-Id: I10ffdce1c7f75dcf448da14040fda78f0d75fd1d Reviewed-on: https://go-review.googlesource.com/c/go/+/627716 Reviewed-by: Cherry Mui <cherryyz@google.com> Reviewed-by: Michael Pratt <mpratt@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
2024-11-07cmd/internal/objabi, cmd/link: introduce SymKind helper methodsRuss Cox
These will be necessary when we start using the new FIPS symbols. Split into a separate CL so that these refactoring changes can be tested separate from any FIPS-specific changes. Passes golang.org/x/tools/cmd/toolstash/buildall. Change-Id: I73e5873fcb677f1f572f0668b4dc6f3951d822bc Reviewed-on: https://go-review.googlesource.com/c/go/+/625996 LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Cherry Mui <cherryyz@google.com> Auto-Submit: Russ Cox <rsc@golang.org>
2024-10-14all: wire up swisstable mapsMichael Pratt
Use the new SwissTable-based map in internal/runtime/maps as the basis for the runtime map when GOEXPERIMENT=swissmap. Integration is complete enough to pass all.bash. Notable missing features: * Race integration / concurrent write detection * Stack-allocated maps * Specialized "fast" map variants * Indirect key / elem For #54766. Cq-Include-Trybots: luci.golang.try:gotip-linux-ppc64_power10,gotip-linux-amd64-longtest-swissmap Change-Id: Ie97b656b6d8e05c0403311ae08fef9f51756a639 Reviewed-on: https://go-review.googlesource.com/c/go/+/594596 Reviewed-by: Keith Randall <khr@golang.org> Reviewed-by: Keith Randall <khr@google.com> Reviewed-by: Michael Knyszek <mknyszek@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
2024-08-09cmd/compile: add basic wasmexport supportCherry Mui
This CL adds a compiler directive go:wasmexport, which applies to a Go function and makes it an exported function of the Wasm module being built, so it can be called directly from the host. As proposed in #65199, parameter and result types are limited to 32-bit and 64-bit integers and floats, and there can be at most one result. As the Go and Wasm calling conventions are different, for a wasmexport function we generate a wrapper function does the ABI conversion at compile time. Currently this CL only adds basic support. In particular, - it only supports executable mode, i.e. the Go wasm module calls into the host via wasmimport, which then calls back to Go via wasmexport. Library (c-shared) mode is not implemented yet. - only supports wasip1, not js. - if the exported function unwinds stacks (goroutine switch, stack growth, etc.), it probably doesn't work. TODO: support stack unwinding, c-shared mode, js. For #65199. Change-Id: Id1777c2d44f7d51942c1caed3173c0a82f120cc4 Reviewed-on: https://go-review.googlesource.com/c/go/+/603055 Reviewed-by: Than McIntosh <thanm@golang.org> Reviewed-by: Randy Reddig <randy.reddig@fastly.com> Reviewed-by: David Chase <drchase@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
2024-08-02all: split old and swiss map abi and compiler integrationMichael Pratt
The two map implementations are still identical, but now the compiler targets the appropriate ABI depending on GOEXPERIMENT. For #54766. Cq-Include-Trybots: luci.golang.try:gotip-linux-amd64-longtest,gotip-linux-amd64-longtest-swissmap Change-Id: I8438f64f044ba9de30ddbf2b8ceb9b4edd2d5614 Reviewed-on: https://go-review.googlesource.com/c/go/+/580779 Reviewed-by: Michael Knyszek <mknyszek@google.com> Reviewed-by: Keith Randall <khr@golang.org> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Auto-Submit: Michael Pratt <mpratt@google.com>
2024-06-07cmd/link: don't include deadcoded function symbols in shared build modeCherry Mui
In shared build mode, we include all symbols. This includes function symbols that are deadcoded by the compiler. They don't really get compiled, and their metadata may be missing, causing linker failures. Skip them. Fixes #67635. Change-Id: Ic0e64bd032be499cca26da5e9e3ffbe9998bac05 Reviewed-on: https://go-review.googlesource.com/c/go/+/588316 Reviewed-by: Than McIntosh <thanm@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
2024-04-02internal/abi: clean up type of Kind and Type.Kind_Austin Clements
Currently, Type.Kind_ is a uint8, Kind is a uint, and some of the abi.Kind consts are not of type Kind. Clean this all up by making Kind a uint8, then making Type.Kind a Kind, and finally making all Kind consts actually have type Kind. This has some ripple effect, but I think all of the changes are improvements. Change-Id: If39be74699c2cdb52bf0ad7092d392bc8fb68d15 Reviewed-on: https://go-review.googlesource.com/c/go/+/575579 Auto-Submit: Austin Clements <austin@google.com> Reviewed-by: Keith Randall <khr@golang.org> Reviewed-by: Keith Randall <khr@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
2024-04-02all: use kind* of abiqiulaidongfeng
For #59670 Change-Id: Id66e102f13e529dd041b68ce869026a56f0a1b9b GitHub-Last-Rev: 43aa9376f72bc02a9d86518cdc99494a6b2f8573 GitHub-Pull-Request: golang/go#65564 Reviewed-on: https://go-review.googlesource.com/c/go/+/562298 LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Austin Clements <austin@google.com> Reviewed-by: Dmitri Shuralyov <dmitshur@google.com> Auto-Submit: Austin Clements <austin@google.com>
2024-02-08cmd/compile: move runtime.itab to internal/abi.ITabKeith Randall
Change-Id: I44293452764dc4bc4de8d386153c6402a9cbe409 Reviewed-on: https://go-review.googlesource.com/c/go/+/549435 LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: David Chase <drchase@google.com> Reviewed-by: Than McIntosh <thanm@google.com>
2023-09-20cmd/link, runtime: initialize packages in shared build modeCherry Mui
Currently, for the shared build mode, we don't generate the module inittasks. Instead, we rely on the main executable to do the initialization, for both the executable and the shared library. But, with the model as of CL 478916, the main executable only has relocations to packages that are directly imported. It won't see the dependency edges between packages within a shared library. Therefore indirect dependencies are not included, and thus not initialized. E.g. main imports a, which imports b, but main doesn't directly import b. a and b are in a shared object. When linking main, it sees main depends on a, so it generates main's inittasks to run a's init before main's, but it doesn't know b, so b's init doesn't run. This CL makes it initialize all packages in a shared library when the library is loaded, as any of them could potentially be imported, directly or indirectly. Also, in the runtime, when running the init functions, make sure to go through the DSOs in dependency order. Otherwise packages can be initialized in the wrong order. Fixes #61973. Change-Id: I2a090336fe9fa0d6c7e43912f3ab233c9c47e247 Reviewed-on: https://go-review.googlesource.com/c/go/+/520375 Reviewed-by: Than McIntosh <thanm@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
2023-09-07cmd/link: avoid deadcode of global map vars for programs using pluginsThan McIntosh
If a program imports the plugin package, the mechanisms in place for detecting and deleting unused global map variables are no longer safe, since it's possibly for a given global map var to be unreferenced in the main program but referenced by a plugin. This patch changes the linker to test for plugin use and to avoid removing any unused global map variables if the main program could possibly load up a plugin. Fixes #62430. Change-Id: Ie00b18b681cb0d259e3c859ac947ade5778cd6c8 Reviewed-on: https://go-review.googlesource.com/c/go/+/526115 LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Cherry Mui <cherryyz@google.com>
2023-09-01cmd/internal/objabi: rename R_USEGENERICIFACEMETHOD to R_USENAMEDMETHOD.Dominique Lefevre
Now we have two cases when we want to keep methods with a specific name: calls to generic interface methods and MethodByName("Foo"). Both use the same relocation type, so let us give it a name that is not limited to the implementation of generic interfaces. Also, introduce staticdata.StrSymNoCommon(). It creates a symbol that does not appear in the final binary and only communicates arguments to the linker. Change-Id: Icc9f49febfde1f31a4455b5acb903e8838d1c0af Reviewed-on: https://go-review.googlesource.com/c/go/+/523016 Run-TryBot: Cherry Mui <cherryyz@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Cherry Mui <cherryyz@google.com> Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
2023-09-01cmd/link: remove special cases for Method() and MethodByName().Dominique Lefevre
There is no more need to do this in the linker. The compiler now handles both Type.Method() and Value.Method(), and flags their users as ReflectMethod. Change-Id: Ice93d5d975a1b93a324471e8abdebdce141d17d0 Reviewed-on: https://go-review.googlesource.com/c/go/+/522437 Run-TryBot: Cherry Mui <cherryyz@google.com> Reviewed-by: Joedian Reid <joedian@golang.org> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Cherry Mui <cherryyz@google.com>
2023-05-19cmd/compile: constant-fold loads from constant dictionaries and typesKeith Randall
Retrying the original CL with a small modification. The original CL did not handle the case of reading an itab out of a dictionary correctly. When we read an itab out of a dictionary, we must treat the type inside that itab as maybe being put in an interface. Original CL: 486895 Revert CL: 490156 Change-Id: Id2dc1699d184cd8c63dac83986a70b60b4e6cbd7 Reviewed-on: https://go-review.googlesource.com/c/go/+/491495 Reviewed-by: Matthew Dempsky <mdempsky@google.com> Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com> Run-TryBot: Keith Randall <khr@golang.org> Reviewed-by: Keith Randall <khr@google.com> TryBot-Result: Gopher Robot <gobot@golang.org>
2023-05-19cmd/link: add ReflectMethod flag to -dumpdep outputAlessandro Arzilli
Adds ReflectMethod flag to the output of -dumpdep. Fixes #60221 Change-Id: I631d72ee21b819a3a629780317ff4d962cc121e0 Reviewed-on: https://go-review.googlesource.com/c/go/+/495715 TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Cherry Mui <cherryyz@google.com> Run-TryBot: Alessandro Arzilli <alessandro.arzilli@gmail.com> Reviewed-by: Heschi Kreinick <heschi@google.com>
2023-05-02cmd/link: remove allocation in decoding type nameCherry Mui
The type name symbol is always from a Go object file and we never change it. Convert the data to string using unsafe conversion without allocation. Linking cmd/go (on macOS/amd64), name old alloc/op new alloc/op delta Deadcode_GC 1.25MB ± 0% 1.17MB ± 0% -6.29% (p=0.000 n=20+20) name old allocs/op new allocs/op delta Deadcode_GC 8.98k ± 0% 0.10k ± 3% -98.91% (p=0.000 n=20+20) Change-Id: I33117ad1f991e4f14ce0b38cceec50b041e3c0a4 Reviewed-on: https://go-review.googlesource.com/c/go/+/490915 TryBot-Result: Gopher Robot <gobot@golang.org> Run-TryBot: Cherry Mui <cherryyz@google.com> Reviewed-by: Than McIntosh <thanm@google.com>
2023-04-14cmd/link: establish dependable package initialization orderKeith Randall
(This is a retry of CL 462035 which was reverted at 474976. The only change from that CL is the aix fix SRODATA->SNOPTRDATA at inittask.go:141) As described here: https://github.com/golang/go/issues/31636#issuecomment-493271830 "Find the lexically earliest package that is not initialized yet, but has had all its dependencies initialized, initialize that package, and repeat." Simplify the runtime a bit, by just computing the ordering required in the linker and giving a list to the runtime. Update #31636 Fixes #57411 RELNOTE=yes Change-Id: I28c09451d6aa677d7394c179d23c2c02c503fc56 Reviewed-on: https://go-review.googlesource.com/c/go/+/478916 Reviewed-by: Than McIntosh <thanm@google.com> Reviewed-by: Cherry Mui <cherryyz@google.com> Run-TryBot: Keith Randall <khr@golang.org> TryBot-Result: Gopher Robot <gobot@golang.org>
2023-03-09Revert "cmd/link: establish dependable package initialization order"Keith Randall
This reverts commit ce2a609909d9de3391a99a00fe140506f724f933. aka CL 462035 Reason for revert: this CL is causing some problems in some internal Google programs. Change-Id: I4476b8d8d2c3d7b5703d1d85c93baebb4b4e5d26 Reviewed-on: https://go-review.googlesource.com/c/go/+/474976 Reviewed-by: Cherry Mui <cherryyz@google.com> Run-TryBot: Keith Randall <khr@golang.org> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Than McIntosh <thanm@google.com>
2023-03-03cmd/link: establish dependable package initialization orderKeith Randall
As described here: https://github.com/golang/go/issues/31636#issuecomment-493271830 "Find the lexically earliest package that is not initialized yet, but has had all its dependencies initialized, initialize that package, and repeat." Simplify the runtime a bit, by just computing the ordering required in the linker and giving a list to the runtime. Update #31636 Fixes #57411 RELNOTE=yes Change-Id: I1e4d3878ebe6e8953527aedb730824971d722cac Reviewed-on: https://go-review.googlesource.com/c/go/+/462035 Reviewed-by: Than McIntosh <thanm@google.com> Reviewed-by: Cherry Mui <cherryyz@google.com> Run-TryBot: Keith Randall <khr@golang.org> TryBot-Result: Gopher Robot <gobot@golang.org>
2023-02-06cmd/link: linker portion of dead map removalThan McIntosh
This patch contains the linker changes needed to enable deadcoding of large unreferenced map variables, in combination with a previous compiler change. We add a new cleanup function that runs just after deadcode that looks for relocations in "init" funcs that are weak, of type R_CALL (and siblings), and are targeting an unreachable function. If we find such a relocation, after checking to make sure it targets a map.init.XXX helper, we redirect the relocation to a point to a no-op routine ("mapinitnoop") in the runtime. Compilebench results for this change: │ out.base.txt │ out.wrap.txt │ │ sec/op │ sec/op vs base │ Template 218.6m ± 2% 221.1m ± 1% ~ (p=0.129 n=39) Unicode 180.5m ± 1% 178.9m ± 1% -0.93% (p=0.006 n=39) GoTypes 1.162 ± 1% 1.156 ± 1% ~ (p=0.850 n=39) Compiler 143.6m ± 1% 142.6m ± 1% ~ (p=0.743 n=39) SSA 8.698 ± 1% 8.719 ± 1% ~ (p=0.145 n=39) Flate 142.6m ± 1% 143.9m ± 3% ~ (p=0.287 n=39) GoParser 247.7m ± 1% 248.8m ± 1% ~ (p=0.265 n=39) Reflect 588.0m ± 1% 590.4m ± 1% ~ (p=0.269 n=39) Tar 198.5m ± 1% 201.3m ± 1% +1.38% (p=0.005 n=39) XML 259.1m ± 1% 260.0m ± 1% ~ (p=0.376 n=39) LinkCompiler 746.8m ± 2% 747.8m ± 1% ~ (p=0.706 n=39) ExternalLinkCompiler 1.906 ± 0% 1.902 ± 1% ~ (p=0.207 n=40) LinkWithoutDebugCompiler 522.4m ± 21% 471.1m ± 1% -9.81% (p=0.000 n=40) StdCmd 21.32 ± 0% 21.39 ± 0% +0.32% (p=0.035 n=40) geomean 609.2m 606.0m -0.53% │ out.base.txt │ out.wrap.txt │ │ user-sec/op │ user-sec/op vs base │ Template 401.9m ± 3% 406.9m ± 2% ~ (p=0.291 n=39) Unicode 191.9m ± 6% 196.1m ± 3% ~ (p=0.052 n=39) GoTypes 3.967 ± 3% 4.056 ± 1% ~ (p=0.099 n=39) Compiler 171.1m ± 3% 173.4m ± 3% ~ (p=0.415 n=39) SSA 30.04 ± 4% 30.25 ± 4% ~ (p=0.106 n=39) Flate 246.3m ± 3% 248.9m ± 4% ~ (p=0.499 n=39) GoParser 518.7m ± 1% 520.6m ± 2% ~ (p=0.531 n=39) Reflect 1.670 ± 1% 1.656 ± 2% ~ (p=0.137 n=39) Tar 352.7m ± 2% 360.3m ± 2% ~ (p=0.117 n=39) XML 528.8m ± 2% 521.1m ± 2% ~ (p=0.296 n=39) LinkCompiler 1.128 ± 2% 1.140 ± 2% ~ (p=0.324 n=39) ExternalLinkCompiler 2.165 ± 2% 2.147 ± 2% ~ (p=0.537 n=40) LinkWithoutDebugCompiler 484.2m ± 4% 490.7m ± 3% ~ (p=0.897 n=40) geomean 818.5m 825.1m +0.80% │ out.base.txt │ out.wrap.txt │ │ text-bytes │ text-bytes vs base │ HelloSize 766.0Ki ± 0% 766.0Ki ± 0% ~ (p=1.000 n=40) ¹ CmdGoSize 10.02Mi ± 0% 10.02Mi ± 0% -0.03% (n=40) geomean 2.738Mi 2.738Mi -0.01% ¹ all samples are equal │ out.base.txt │ out.wrap.txt │ │ data-bytes │ data-bytes vs base │ HelloSize 14.17Ki ± 0% 14.17Ki ± 0% ~ (p=1.000 n=40) ¹ CmdGoSize 308.3Ki ± 0% 298.5Ki ± 0% -3.19% (n=40) geomean 66.10Ki 65.04Ki -1.61% ¹ all samples are equal │ out.base.txt │ out.wrap.txt │ │ bss-bytes │ bss-bytes vs base │ HelloSize 197.3Ki ± 0% 197.3Ki ± 0% ~ (p=1.000 n=40) ¹ CmdGoSize 228.2Ki ± 0% 228.1Ki ± 0% -0.01% (n=40) geomean 212.2Ki 212.1Ki -0.01% ¹ all samples are equal │ out.base.txt │ out.wrap.txt │ │ exe-bytes │ exe-bytes vs base │ HelloSize 1.192Mi ± 0% 1.192Mi ± 0% +0.00% (p=0.000 n=40) CmdGoSize 14.85Mi ± 0% 14.83Mi ± 0% -0.09% (n=40) geomean 4.207Mi 4.205Mi -0.05% Also tested for any linker changes by benchmarking relink of k8s "kubelet"; no changes to speak of there. Updates #2559. Updates #36021. Updates #14840. Change-Id: I4cc5370b3f20679a1065aaaf87bdf2881e257631 Reviewed-on: https://go-review.googlesource.com/c/go/+/463395 Run-TryBot: Than McIntosh <thanm@google.com> Reviewed-by: Cherry Mui <cherryyz@google.com> TryBot-Result: Gopher Robot <gobot@golang.org>
2022-08-09all: use ":" for compiler generated symbolsCuong Manh Le
As it can't appear in user package paths. There is a hack for handling "go:buildid" and "type:*" on windows/386. Previously, windows/386 requires underscore prefix on external symbols, but that's only applied for SHOSTOBJ/SUNDEFEXT or cgo export symbols. "go.buildid" is STEXT, "type.*" is STYPE, thus they are not prefixed with underscore. In external linking mode, the external linker can't resolve them as external symbols. But we are lucky that they have "." in their name, so the external linker see them as Forwarder RVA exports. See: - https://docs.microsoft.com/en-us/windows/win32/debug/pe-format#export-address-table - https://sourceware.org/git/?p=binutils-gdb.git;a=blob;f=ld/pe-dll.c;h=e7b82ba6ffadf74dc1b9ee71dc13d48336941e51;hb=HEAD#l972) This CL changes "." to ":" in symbols name, so theses symbols can not be found by external linker anymore. So a hacky way is adding the underscore prefix for these 2 symbols. I don't have enough knowledge to verify whether adding the underscore for all STEXT/STYPE symbols are fine, even if it could be, that would be done in future CL. Fixes #37762 Change-Id: I92eaaf24c0820926a36e0530fdb07b07af1fcc35 Reviewed-on: https://go-review.googlesource.com/c/go/+/317917 Reviewed-by: Than McIntosh <thanm@google.com> Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com> Reviewed-by: Cherry Mui <cherryyz@google.com> TryBot-Result: Gopher Robot <gobot@golang.org>
2022-04-11all: gofmt main repoRuss Cox
[This CL is part of a sequence implementing the proposal #51082. The design doc is at https://go.dev/s/godocfmt-design.] Run the updated gofmt, which reformats doc comments, on the main repository. Vendored files are excluded. For #51082. Change-Id: I7332f099b60f716295fb34719c98c04eb1a85407 Reviewed-on: https://go-review.googlesource.com/c/go/+/384268 Reviewed-by: Jonathan Amsterdam <jba@google.com> Reviewed-by: Ian Lance Taylor <iant@golang.org>
2022-03-16cmd/link: mark unexported methods for pluginsCherry Mui
When plugin is used, we already mark all exported methods reachable. However, when the plugin and the host program share a common package, an unexported method could also be reachable from both the plugin and the host via interfaces. We need to mark them as well. Fixes #51621. Change-Id: I1a70d3f96b66b803f2d0ab14d00ed0df276ea500 Reviewed-on: https://go-review.googlesource.com/c/go/+/393365 Trust: Cherry Mui <cherryyz@google.com> Run-TryBot: Cherry Mui <cherryyz@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Than McIntosh <thanm@google.com>
2021-12-07cmd/link, cmd/go: make version info easier to extractRuss Cox
Reading the version information to date has required evaluating two pointers to strings (which themselves contain pointers to data), which means applying relocations, which can be very system-dependent. To simplify the lookup, inline the string data into the build info blob. This makes go version work on binaries built with external linking on darwin/arm64. Also test that at least the very basics work on a trivial binary, even in short mode. Change-Id: I463088c19e837ae0ce57e1278c7b72e74a80b2c4 Reviewed-on: https://go-review.googlesource.com/c/go/+/369977 Trust: Russ Cox <rsc@golang.org> Run-TryBot: Russ Cox <rsc@golang.org> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Cherry Mui <cherryyz@google.com>
2021-10-25cmd/compile,cmd/link: introduce generic interface call relocationsKeith Randall
To capture the fact that a method was called on a generic interface, so we can make sure the linker doesn't throw away any implementations that might be the method called. See the comment in reflect.go for details. Fixes #49049 Change-Id: I0be74b6e727c1ecefedae072b149f59d539dc1e9 Reviewed-on: https://go-review.googlesource.com/c/go/+/357835 Trust: Keith Randall <khr@golang.org> Trust: Dan Scales <danscales@google.com> Run-TryBot: Keith Randall <khr@golang.org> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Cherry Mui <cherryyz@google.com> Reviewed-by: Dan Scales <danscales@google.com> Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
2021-10-13cmd/link: disable weak reference in itab if build with "-linkshared"zhouguangyuan
When build with "-linkshared", we can't tell if the interface method will be used or not. It can be used in shared library. Fixes #47873 Change-Id: Iba12812f199b7679cf2fd41a304268d6d6dd03c6 Reviewed-on: https://go-review.googlesource.com/c/go/+/350189 Reviewed-by: Cherry Mui <cherryyz@google.com> Run-TryBot: Cherry Mui <cherryyz@google.com> TryBot-Result: Go Bot <gobot@golang.org> Trust: Alexander Rakoczy <alex@golang.org>
2021-09-22cmd/compile, cmd/link: avoid ABI aliasesCherry Mui
In the past we introduced ABI aliases, in preparation for ABI wrappers. Now that we have ABI wrappers implemented, we don't need ABI aliases. If ABI wrappers are not enabled, ABI0 and ABIInternal are actually identical, so we can resolve symbol references without distinguish them. This CL does so by normalizing ABIInternal to ABI0 at link time. This way, we no longer need to generate ABI aliases. This CL doesn't clean up everything related to ABI aliases, which will be done in followup CLs. Change-Id: I5b5db43370d29b8ad153078c70a853e3263ae6f7 Reviewed-on: https://go-review.googlesource.com/c/go/+/351271 Trust: Cherry Mui <cherryyz@google.com> Run-TryBot: Cherry Mui <cherryyz@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Than McIntosh <thanm@google.com>
2021-08-09[dev.typeparams] cmd/compile: use types2.Constraint() rather than types2.Bound()Dan Scales
types2.Constraint() returns the top-level constraint type, including any unions or other interface elements. Because of that, we needed to add/fix some code in the type substituter and generic type instantiater in the importer to deal with unions and non-method members of an interface. Also, NewUnion was not correctly setting the HasTParam flag. I also added a better error message when a symbol is not found in (*deadcodePass).decodeIfaceMethod(). Change-Id: Id3668dc596dce63690fa05a9e5e42295b5e2bbb5 Reviewed-on: https://go-review.googlesource.com/c/go/+/340670 Trust: Dan Scales <danscales@google.com> Run-TryBot: Dan Scales <danscales@google.com> Reviewed-by: Keith Randall <khr@golang.org>
2021-05-13cmd/link: always mark runtime.unreachableMethod symbolCherry Mui
In the deadcode path we mark runtime.unreachableMethod symbol, which is a special symbol used for redirecting unreachable methods. Currently this code is conditioned on not -linkshared. This is wrong. It should be marked with -linkshared mode as well. In fact, -linkshared should only affect the entry symbol. Change the code accordingly. Change-Id: I252abf850212a930f275589ef0035a43e52cb9cc Reviewed-on: https://go-review.googlesource.com/c/go/+/319893 Trust: Cherry Mui <cherryyz@google.com> Run-TryBot: Cherry Mui <cherryyz@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Jeremy Faller <jeremy@golang.org>
2021-04-16internal/buildcfg: move build configuration out of cmd/internal/objabiRuss Cox
The go/build package needs access to this configuration, so move it into a new package available to the standard library. Change-Id: I868a94148b52350c76116451f4ad9191246adcff Reviewed-on: https://go-review.googlesource.com/c/go/+/310731 Trust: Russ Cox <rsc@golang.org> Run-TryBot: Russ Cox <rsc@golang.org> Reviewed-by: Austin Clements <austin@google.com> Reviewed-by: Jay Conrod <jayconrod@google.com>
2021-04-13cmd/link: build dynexp symbol list directlyAustin Clements
Currently, setCgoAttr populates the cgo_export_{static,dynamic} maps with symbol names of exported symbols, which are then re-looked-up by deadcode and setupdynexp, which in turn puts the re-looked-up symbols in ctxt.dynexp. setCgoAttr already looked up the Syms, so simplify all of this by making setCgoAttr populate ctxt.dynexp directly and eliminating the cgo_export_{static,dynamic} maps. Recording Syms directly also sets us up to use correct symbol versions for these exports, rather than just assuming version 0 for all lookups. Since setupdynexp doesn't really do any "setting up" of dynexp any more with this change, we fold the remaining logic from setupdynexp directly into addexport, where it has better context anyway. This also eliminates a sorting step, since we no longer do a non-deterministic map iteration to build the dynexp slice. For #40724. Change-Id: I3e1a65165268da8c2bf50d7485f2624133433260 Reviewed-on: https://go-review.googlesource.com/c/go/+/309340 Trust: Austin Clements <austin@google.com> Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com> Reviewed-by: Than McIntosh <thanm@google.com>
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>
2021-03-18cmd: move experiment flags into objabi.ExperimentAustin Clements
This moves all remaining GOEXPERIMENT flags into the objabi.Experiment struct, drops the "_enabled" from their name, and makes them all bool typed. We also drop DebugFlags.Fieldtrack because the previous CL shifted the one test that used it to use GOEXPERIMENT instead. Change-Id: I3406fe62b1c300bb4caeaffa6ca5ce56a70497fe Reviewed-on: https://go-review.googlesource.com/c/go/+/302389 Trust: Austin Clements <austin@google.com> Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2021-03-15cmd/link/internal/ld: fix typo in a commentTao Qingyun
Change-Id: I9ae39aa2da2bfa6bb5d3f279bca764128d9cc401 GitHub-Last-Rev: 7a5945ae120b911793a1510f371945ac17611440 GitHub-Pull-Request: golang/go#44990 Reviewed-on: https://go-review.googlesource.com/c/go/+/301529 Reviewed-by: Matthew Dempsky <mdempsky@google.com> Trust: Tobias Klauser <tobias.klauser@gmail.com>
2021-03-08cmd/link/internal/ld: fix typo in a commentBrad Fitzpatrick
Change-Id: I6d0fafd38f0ad9392f163a9d8cd94d103bf2a059 Reviewed-on: https://go-review.googlesource.com/c/go/+/299669 Reviewed-by: Keith Randall <khr@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
2021-03-05cmd/internal/objabi: use a separate bit to mark weak relocationCherry Zhang
Instead of using two relocation types R_XXX and R_WEAKXXX, use a separate bit, R_WEAK, to mark weak relocations. This makes it easier to add more weak relocation types. Change-Id: Iec4195c2aefa65f59e464c83018246e17cd08173 Reviewed-on: https://go-review.googlesource.com/c/go/+/268478 Trust: Cherry Zhang <cherryyz@google.com> Run-TryBot: Cherry Zhang <cherryyz@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Jeremy Faller <jeremy@golang.org> Reviewed-by: Than McIntosh <thanm@google.com>
2021-02-26cmd/link: handle types as converted to interface when dynlinkCherry Zhang
When using plugins, a type (whose value) may be pass to a plugin and get converted to interface there, or vice versa. We need to treat the type as potentially converted to interface, and retain its methods. Should fix #44586. Change-Id: I80dd35e68baedaa852a317543ccd78d94628d13b Reviewed-on: https://go-review.googlesource.com/c/go/+/296709 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>
2021-02-19cmd/link: add debug print in deadcodeRuss Cox
This matches the prints that deadcode prints later as the algorithm progresses under -v=2. It helps to see the initial conditions with -v=2 as well. Change-Id: I06ae86fe9bd8314d003148f3d941832c9b10aef1 Reviewed-on: https://go-review.googlesource.com/c/go/+/288817 Trust: Russ Cox <rsc@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
2021-02-02cmd/link: don't decode type symbol in shared library in deadcodeCherry Zhang
In the linker's deadcode pass we decode type symbols for interface satisfaction analysis. When linking against Go shared libraries, the type symbol may come from a shared library, so it doesn't have data in the current module being linked, so we cannot decode it. We already have code to skip DYNIMPORT symbols. However, this doesn't actually work, because at that point the type symbols' names haven't been mangled, whereas they may be mangled in the shared library. So the symbol definition (in shared library) and reference (in current module) haven't been connected. Skip decoding type symbols of type Sxxx (along with DYNIMPORT) when linkShared. Note: we cannot skip all type symbols, as we still need to mark unexported methods defined in the current module. Fixes #44031. Change-Id: I833d19a060c94edbd6fc448172358f9a7d760657 Reviewed-on: https://go-review.googlesource.com/c/go/+/288496 Trust: Cherry Zhang <cherryyz@google.com> Trust: Than McIntosh <thanm@google.com> Run-TryBot: Cherry Zhang <cherryyz@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Than McIntosh <thanm@google.com>
2020-10-12cmd/link: always mark runtime.buildVersion and runtime.modinfo reachableCherry Zhang
runtime.buildVersion and runtime.modinfo are referenced in the .go.buildinfo section, therefore reachable. They should normally be reachable from the runtime. Just make it explicit, in case. Change-Id: I60ff3132e0bbb690f4a3cba8bb18735921fbe951 Reviewed-on: https://go-review.googlesource.com/c/go/+/261637 Trust: Cherry Zhang <cherryyz@google.com> Run-TryBot: Cherry Zhang <cherryyz@google.com> Reviewed-by: Than McIntosh <thanm@google.com> Reviewed-by: Jeremy Faller <jeremy@golang.org> TryBot-Result: Go Bot <gobot@golang.org>
2020-09-29cmd/link: retain only used interface methodsCherry Zhang
Currently, in the linker's deadcode pass, when an interface type is live, the linker thinks all its methods are live, and uses them to match methods on concrete types. The interface method may never be used, though. This CL changes it to only keep used interface methods, for matching concrete type methods. To do that, when an interface method is used, the compiler generates a mark relocation. The linker uses the marker relocations to mark used interface methods, and only the used ones. binary size before after cmd/compile 18887400 18812200 cmd/go 13470652 13470492 Change-Id: I3cfd9df4a53783330ba87735853f2a0ec3c42802 Reviewed-on: https://go-review.googlesource.com/c/go/+/256798 Trust: Cherry Zhang <cherryyz@google.com> Reviewed-by: Than McIntosh <thanm@google.com> Reviewed-by: Jeremy Faller <jeremy@golang.org>
2020-09-28cmd/link: consider interface conversions only in reachable codeCherry Zhang
The linker prunes methods that are not directly reachable if the receiver type is never converted to interface. Currently, this "never" is too strong: it is invalidated even if the interface conversion is in an unreachable function. This CL improves it by only considering interface conversions in reachable code. To do that, we introduce a marker relocation R_USEIFACE, which marks the target symbol as UsedInIface if the source symbol is reached. binary size before after cmd/compile 18897528 18887400 cmd/go 13607372 13470652 Change-Id: I66c6b69eeff9ae02d84d2e6f2bc7f1b29dd53910 Reviewed-on: https://go-review.googlesource.com/c/go/+/256797 Trust: Cherry Zhang <cherryyz@google.com> Reviewed-by: Jeremy Faller <jeremy@golang.org> Reviewed-by: Than McIntosh <thanm@google.com>
2020-09-18cmd/link: don't mark a symbol's GoType reachable when -linksharedCherry Zhang
In CL 231397, we stopped marking symbols' GoType reachable in general, but not when -linkshared. It was left as a TODO. This CL addresses it. The problem was that the type names are mangled in the shared library, so we need to mangle the name consistently in the executable as well (regardless of whether the symbol is reachable or not), so that the GCProg generation code can find the corresponding symbol from the shared library. Change-Id: I1040747402929a983ec581109f1681a77893682e Reviewed-on: https://go-review.googlesource.com/c/go/+/255964 Trust: Cherry Zhang <cherryyz@google.com> Run-TryBot: Cherry Zhang <cherryyz@google.com> Reviewed-by: Jeremy Faller <jeremy@golang.org> Reviewed-by: Than McIntosh <thanm@google.com> TryBot-Result: Go Bot <gobot@golang.org>
2020-09-18cmd/link: propagate UsedInIface through method descriptorCherry Zhang
The linker prunes methods that are not directly reachable if the receiver type is never converted to interface. A type can be converted to interface using reflection through other types. The linker already takes this into consideration but it missed the case that the intermediate is a method descriptor. Handle this case. Change-Id: I590efc5da163c326db8d43583908a2ef67f65d9d Reviewed-on: https://go-review.googlesource.com/c/go/+/255858 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> Reviewed-by: Jeremy Faller <jeremy@golang.org>
2020-09-11cmd/link: record only the first occurance in Reachparent graphCherry Zhang
In the deadcode pass, a type symbol may be marked twice, one without UsedInIface, one with. For the second time, don't update the Reachparent graph, so it only records the path of the first time the symbol is reached. This ensures the Reachparent graph is acyclic. TODO: add a test. (This only affects GOEXPERIMENT=fieldtrack) Change-Id: I68e8a1a69c3830bc8aee5df946151dc22dcb2b29 Reviewed-on: https://go-review.googlesource.com/c/go/+/254297 Run-TryBot: Cherry Zhang <cherryyz@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Than McIntosh <thanm@google.com>
2020-08-11[dev.link] cmd: remove "2", another roundCherry Zhang
Rename the goobj2 package to goobj. Change-Id: Iff97b5575cbac45ac44de96b6bd9d555b9a4a12a Reviewed-on: https://go-review.googlesource.com/c/go/+/246444 Run-TryBot: Cherry Zhang <cherryyz@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Austin Clements <austin@google.com>
2020-08-03[dev.link] cmd/compile, cmd/link: generate itablink at link timeCherry Zhang
Currently, at compile time, for each itab symbol, we create an "itablink" symbol which holds solely the address of the itab symbol. At link time, all the itablink symbols are grouped together to form the itablinks slice. This CL removes the itablink symbols, and directly generate the itablinks slice in the linker. This removes a number of symbols, which are dupOK and generally have long names. And also removes a special handling of itablink symbols in the deadcode pass which iterates through all symbols. Change-Id: I475c3c8899e9fbeec9abc7647b1e4a69aa5c3c5a Reviewed-on: https://go-review.googlesource.com/c/go/+/245901 Reviewed-by: Jeremy Faller <jeremy@golang.org>
2020-07-30[dev.link] cmd/link: remove "2", another roundCherry Zhang
Rename Reloc2 to Reloc, At2 to At, Aux2 to Aux. Change-Id: Ic98d83c080e8cd80fbe1837c8f0aa134033508ce Reviewed-on: https://go-review.googlesource.com/c/go/+/245578 Reviewed-by: Jeremy Faller <jeremy@golang.org>
generated by cgit v1.3 (git 2.53.0) at 2026-04-15 13:44:13 +0000