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14 dayscmd/asm, cmd/go: pass -std to assembler for standard library packagesCherry Mui
For the compiler, we already pass -std when compiling the standard library. Do the same for the assembler. So the assembler and the linker can tell which objects are in the standard library. Change-Id: I35d28a4c72d32c344eda37a3ff407ea525ee5cea Reviewed-on: https://go-review.googlesource.com/c/go/+/761200 LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Michael Matloob <matloob@golang.org> Reviewed-by: Michael Matloob <matloob@google.com>
2025-11-18cmd/asm,cmd/compile,cmd/internal/obj/riscv: use compressed instructions on ↵Joel Sing
riscv64 Make use of compressed instructions on riscv64 - add a compress pass to the end of the assembler, which replaces non-compressed instructions with compressed alternatives if possible. Provide a `compressinstructions` compiler and assembler debug flag, such that the compression pass can be disabled via `-asmflags=all=-d=compressinstructions=0` and `-gcflags=all=-d=compressinstructions=0`. Note that this does not prevent the explicit use of compressed instructions via assembly. Note that this does not make use of compressed control transfer instructions - this will be implemented in later changes. Reduces the text size of a hello world binary by ~121KB and reduces the text size of the go binary on riscv64 by ~1.21MB (between 8-10% in both cases). Updates #71105 Cq-Include-Trybots: luci.golang.try:gotip-linux-riscv64 Change-Id: I24258353688554042c2a836deed4830cc673e985 Reviewed-on: https://go-review.googlesource.com/c/go/+/523478 Reviewed-by: Mark Ryan <markdryan@rivosinc.com> Reviewed-by: Mark Freeman <markfreeman@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Cherry Mui <cherryyz@google.com>
2025-11-11std,cmd: go fix -any std cmdAlan Donovan
This change mechanically replaces all occurrences of interface{} by 'any' (where deemed safe by the 'any' modernizer) throughout std and cmd, minus their vendor trees. Since this fix is relatively numerous, it gets its own CL. Also, 'go generate go/types'. Change-Id: I14a6b52856c3291c1d27935409bca8d5fd4242a2 Reviewed-on: https://go-review.googlesource.com/c/go/+/719702 Commit-Queue: Alan Donovan <adonovan@google.com> Reviewed-by: Dmitri Shuralyov <dmitshur@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org> Auto-Submit: Alan Donovan <adonovan@google.com>
2025-10-20cmd/asm: fix typo in commentJoel Sing
Change-Id: I1a7933bce70bcae1f93a45c6810da60d269f48f3 Reviewed-on: https://go-review.googlesource.com/c/go/+/713000 LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Michael Pratt <mpratt@google.com> Reviewed-by: Keith Randall <khr@google.com> Auto-Submit: Joel Sing <joel@sing.id.au>
2025-04-13cmd: fix DWARF gen bug with packages that use assemblyThan McIntosh
When the compiler builds a Go package with DWARF 5 generation enabled, it emits relocations into various generated DWARF symbols (ex: SDWARFFCN) that use the R_DWTXTADDR_* flavor of relocations. The specific size of this relocation is selected based on the total number of functions in the package -- if the package is tiny (just a couple funcs) we can use R_DWTXTADDR_U1 relocs (which target just a byte); if the package is larger we might need to use the 2-byte or 3-byte flavor of this reloc. Prior to this patch, the strategy used to pick the right relocation size was flawed in that it didn't take into account packages with assembly code. For example, if you have a package P with 200 funcs written in Go source and 200 funcs written in assembly, you can't use the R_DWTXTADDR_U1 reloc flavor for indirect text references since the real function count for the package (asm + go) exceeds 255. The new strategy (with this patch) is to have the compiler look at the "symabis" file to determine the count of assembly functions. For the assembler, rather than create additional plumbing to pass in the Go source func count we just use an dummy (artificially high) function count so as to select a relocation that will be large enough. Fixes #72810. Updates #26379. Change-Id: I98d04f3c6aacca1dafe1f1610c99c77db290d1d8 Reviewed-on: https://go-review.googlesource.com/c/go/+/663235 Reviewed-by: Dmitri Shuralyov <dmitshur@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: David Chase <drchase@google.com>
2024-06-21cmd/internal: separate counter package from telemetry packageMichael Matloob
Move the code that opens and increments counters out of the cmd/internal/telemetry package into cmd/internal/telemetry/counter. The telemetry package has dependencies on the upload code, which we do not want to pull into the rest of the go toolchain. For #68109 Change-Id: I463c106819b169177a783de4a7d93377e81f4e3e Reviewed-on: https://go-review.googlesource.com/c/go/+/593976 LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Robert Findley <rfindley@google.com>
2024-06-13cmd/go: call telemetry.MaybeChild at start of go commandMichael Matloob
Call the new telemetry.MaybeChild function at the start of the go command so that the child process logic can be run immediately without running toolchain selection if this is the child process. The Start function in the telemetry shim package has been renamed to OpenCounters to make it clear that that's its only function. The StartWithUpload function in the telemetry shim package has been renamed to MaybeParent because that's its actual effective behavior in cmd/go, the only place it's called: it won't run as the child because MaybeChild has already been called and would have run as the child if the program was the telemetry child, and it won't open counters because telemetry.Start has been called. Checks are added that those functions are always called before so that the function name and comment are accurate. It might make sense to add a true telemetry.MaybeParent function that doesn't try to start the child or open counters to make things a little simpler. Change-Id: Ie81e2418af85cef18ec41f75db66365f6597b8b1 Reviewed-on: https://go-review.googlesource.com/c/go/+/592535 Reviewed-by: Robert Findley <rfindley@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
2024-05-14cmd: add telemetry for commands in cmdMichael Matloob
This change modifies the commands in cmd to open counter files, increment invocations counters and to increment counters for the names of the flags that were passed in. cmd/pprof and cmd/vet are both wrappers around tools defined in other modules which do their own flag processing so we can't directly increment flag counters right after flags are parsed. For those two commands we wait to increment counters until after the programs have returned. cmd/dist is built with the bootstrap go so it can't depend on telemetry yet. We can add telemetry support to it once 1.23 is the minimum bootstrap version. For #58894 Change-Id: Ic7f6009992465e55c56ad4dc6451bcb1ca51374a Reviewed-on: https://go-review.googlesource.com/c/go/+/585235 Reviewed-by: Sam Thanawalla <samthanawalla@google.com> Reviewed-by: Cherry Mui <cherryyz@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
2023-08-29cmd: simplify some handling of package pathsMatthew Dempsky
We have obj.Link.Pkgpath, so we don't need to pass it redundantly in places where we already have an *obj.Link. Also, renaming the parser's "compilingRuntime" field to "allowABI", to match the "AllowAsmABI" name used by objabi.LookupPkgSpecial. Finally, push the handling of GOEXPERIMENT_* flags up to cmd/asm's main entry point, by simply appending them to flags.D. Change-Id: I6ada134522b0cbc90d35bcb145fbe045338fefb7 Reviewed-on: https://go-review.googlesource.com/c/go/+/523297 Run-TryBot: Matthew Dempsky <mdempsky@google.com> Reviewed-by: Cherry Mui <cherryyz@google.com> Auto-Submit: Matthew Dempsky <mdempsky@google.com> TryBot-Result: Gopher Robot <gobot@golang.org>
2023-08-22cmd/internal/objabi: generalize "is runtime package" checkAustin Clements
There are several implementations of "is this package path a runtime package". They all have slightly different lists because they all care about slightly different properties of building the runtime. To start converging these, we replace objabi.IsRuntimePackagePath with objabi.LookupPkgSpecial, which returns a struct we can extend with various special build properties. We'll extend this with several other flags in the following CLs. Change-Id: I21959cb8c3d18a350d6060467681c72ea49af712 Reviewed-on: https://go-review.googlesource.com/c/go/+/521698 Reviewed-by: Matthew Dempsky <mdempsky@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Run-TryBot: Austin Clements <austin@google.com>
2023-08-22cmd/asm,cmd/dist,cmd/go: remove asm -compiling-runtime flagAustin Clements
Currently, dist and go pass a -compiling-runtime flag to asm if they're compiling a runtime package. However, now that we always pass the package path to asm, it can make that determination just as well as its callers can. This CL moves that check into asm and drops the flag. This in turn makes dist's copy of IsRuntimePackagePath unnecessary, so we delete it. Change-Id: I6ecf2d50b5b83965012af34dbe5f9a973ba0778b Reviewed-on: https://go-review.googlesource.com/c/go/+/521697 Run-TryBot: Austin Clements <austin@google.com> Reviewed-by: Matthew Dempsky <mdempsky@google.com> TryBot-Result: Gopher Robot <gobot@golang.org>
2022-03-15cmd/asm: support -d=pctab flagCherry Mui
To debug PC data generation. Change-Id: Id7ac8d607cc27ad52db490bd758c3a768c3e1df2 Reviewed-on: https://go-review.googlesource.com/c/go/+/388015 Trust: Cherry Mui <cherryyz@google.com> Run-TryBot: Cherry Mui <cherryyz@google.com> Reviewed-by: Than McIntosh <thanm@google.com> TryBot-Result: Gopher Robot <gobot@golang.org>
2021-11-05cmd/{asm,compile,internal/obj}: add "maymorestack" supportAustin Clements
This adds a debugging hook for optionally calling a "maymorestack" function in the prologue of any function that might call morestack (whether it does at run time or not). The maymorestack function will let us improve lock checking and add debugging modes that stress function preemption and stack growth. Passes toolstash-check -all (except on js/wasm, where toolstash appears to be broken) Fixes #48297. Change-Id: I27197947482b329af75dafb9971fc0d3a52eaf31 Reviewed-on: https://go-review.googlesource.com/c/go/+/359795 Trust: Austin Clements <austin@google.com> Run-TryBot: Austin Clements <austin@google.com> Reviewed-by: Cherry Mui <cherryyz@google.com>
2021-11-03cmd/asm,cmd/compile,runtime: stop using X3 (aka GP) on riscv64Joel Sing
The X3 (aka GP) register will potentially be loaded with the __global_pointer$ symbol during program start up (usually by the dynamic linker). As such, non-Go code may depend on the contents of GP and calculate offsets based on it, including code called via cgo and signal handlers installed by non-Go code. As such, stop using the X3 register so that there are fewer issues interacting between Go and non-Go code. While here remove the X4 (TP) name from the assembler such that any references must use the 'TP' name. This should reduce the likelihood of accidental use (like we do for the 'g' register). The same applies for X3 (GP) when the -shared flag is given. Updates #47100 Change-Id: I72e82b5ca3f80c46a781781345ca0432a4111b74 Reviewed-on: https://go-review.googlesource.com/c/go/+/351859 Trust: Joel Sing <joel@sing.id.au> Run-TryBot: Joel Sing <joel@sing.id.au> Reviewed-by: Cherry Mui <cherryyz@google.com> TryBot-Result: Go Bot <gobot@golang.org>
2021-04-23cmd/asm, cmd/link: use full objabi headerRuss Cox
The cmd/link check of the objabi header was a bit lax because historically the assembler has not included the full version string. And the assembler didn't do that because it didn't have access to it: that was buried inside the compiler. But now that we have cmd/internal/objabi, all the tools have full access to the expected string, and they can use it, which simplifies the cmd/link consistency check. Do that. Change-Id: I33bd2f9d36c373cc3c32ff02ec6368365088b011 Reviewed-on: https://go-review.googlesource.com/c/go/+/312030 Trust: Russ Cox <rsc@golang.org> Run-TryBot: Russ Cox <rsc@golang.org> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
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>
2021-02-19cmd/asm, cmd/link, runtime: introduce FuncInfo flag bitsRuss Cox
The runtime traceback code has its own definition of which functions mark the top frame of a stack, separate from the TOPFRAME bits that exist in the assembly and are passed along in DWARF information. It's error-prone and redundant to have two different sources of truth. This CL provides the actual TOPFRAME bits to the runtime, so that the runtime can use those bits instead of reinventing its own category. This CL also adds a new bit, SPWRITE, which marks functions that write directly to SP (anything but adding and subtracting constants). Such functions must stop a traceback, because the traceback has no way to rederive the SP on entry. Again, the runtime has its own definition which is mostly correct, but also missing some functions. During ordinary goroutine context switches, such functions do not appear on the stack, so the incompleteness in the runtime usually doesn't matter. But profiling signals can arrive at any moment, and the runtime may crash during traceback if it attempts to unwind an SP-writing frame and gets out-of-sync with the actual stack. The runtime contains code to try to detect likely candidates but again it is incomplete. Deriving the SPWRITE bit automatically from the actual assembly code provides the complete truth, and passing it to the runtime lets the runtime use it. This CL is part of a stack adding windows/arm64 support (#36439), intended to land in the Go 1.17 cycle. This CL is, however, not windows/arm64-specific. It is cleanup meant to make the port (and future ports) easier. Change-Id: I227f53b23ac5b3dabfcc5e8ee3f00df4e113cf58 Reviewed-on: https://go-review.googlesource.com/c/go/+/288800 Trust: Russ Cox <rsc@golang.org> Trust: Jason A. Donenfeld <Jason@zx2c4.com> Reviewed-by: Cherry Zhang <cherryyz@google.com> Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com>
2020-12-10cmd/go, cmd/asm: pass -linkshared to assembler for shared linkage buildsThan McIntosh
When the -linkshared build mode is in effect, the Go command passes the "-linkshared" command line option to the compiler so as to insure special handling for things like builtin functions (which may appear in a shared library and not the main executable). This patch extends this behavior to the assembler, since the assembler may also wind up referencing builtins when emitting a stack-split prolog. Fixes #43107. Change-Id: I56eaded79789b083f3c3d800fb140353dee33ba9 Reviewed-on: https://go-review.googlesource.com/c/go/+/276932 Trust: Than McIntosh <thanm@google.com> Run-TryBot: Than McIntosh <thanm@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Jay Conrod <jayconrod@google.com> Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-10-19cmd/dist,cmd/go: broaden use of asm macro GOEXPERIMENT_REGABIThan McIntosh
This extends a change made in https://golang.org/cl/252258 to the go command (to define an asm macro when GOEXPERIMENT=regabi is in effect); we need this same macro during the bootstrap build in order to build the runtime correctly. In addition, expand the set of packages where the macro is applied to {runtime, reflect, syscall, runtime/internal/*}, and move the logic for deciding when something is a "runtime package" out of the assembler and into cmd/{go,dist}, introducing a new assembler command line flag instead. Updates #27539, #40724. Change-Id: Ifcc7f029f56873584de1e543c55b0d3e54ad6c49 Reviewed-on: https://go-review.googlesource.com/c/go/+/262317 Trust: Than McIntosh <thanm@google.com> Run-TryBot: Than McIntosh <thanm@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Austin Clements <austin@google.com> Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-10-19cmd/asm: allow def/ref of func ABI when compiling runtimeThan McIntosh
Function symbols defined and referenced by assembly source currently always default to ABI0; this patch adds preliminary support for accepting an explicit ABI selector clause for func defs/refs. This functionality is currently only enabled when compiling runtime-related packages (runtime, syscall, reflect). Examples: TEXT ·DefinedAbi0Symbol<ABI0>(SB),NOSPLIT,$0 RET TEXT ·DefinedAbi1Symbol<ABIInternal>(SB),NOSPLIT,$0 CALL ·AbiZerolSym<ABI0>(SB) ... JMP ·AbiInternalSym<ABIInternal>(SB) RET Also included is a small change to the code in the compiler that reads the symabis file emitted by the assembler. New behavior is currently gated under GOEXPERIMENT=regabi. Updates #27539, #40724. Change-Id: Ia22221fe26df0fa002191cfb13bdfaaa38d7df38 Reviewed-on: https://go-review.googlesource.com/c/go/+/260477 Run-TryBot: Than McIntosh <thanm@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com> Trust: Than McIntosh <thanm@google.com>
2020-09-17cmd/asm: make asm -S flag consistent with compile -S flagThan McIntosh
Change things so that the -S command line option for the assembler works the same as -S in the compiler, e.g. you can use -S=2 to get additional detail. Change-Id: I7bdfba39a98e67c7ae4b93019e171b188bb99a2d Reviewed-on: https://go-review.googlesource.com/c/go/+/255717 Trust: Than McIntosh <thanm@google.com> Run-TryBot: Than McIntosh <thanm@google.com> Reviewed-by: Cherry Zhang <cherryyz@google.com> Reviewed-by: David Chase <drchase@google.com> TryBot-Result: Go Bot <gobot@golang.org>
2020-07-20[dev.link] cmd/internal/obj: handle content-addressable symbols with relocationsCherry Zhang
For content-addressable symbols with relocations, we build a content hash based on its content and relocations. Depending on the category of the referenced symbol, we choose different hash algorithms such that the hash is globally consistent. For now, we only support content-addressable symbols with relocations when the current package's import path is known, so that the symbol names are fully expanded. Otherwise, if the referenced symbol is a named symbol whose name is not fully expanded, the hash won't be globally consistent, and can cause erroneous collisions. This is fine for now, as the deduplication is just an optimization, not a requirement for correctness (until we get to type descriptors). Change-Id: I639e4e03dd749b5d71f0a55c2525926575b1ac30 Reviewed-on: https://go-review.googlesource.com/c/go/+/243142 Run-TryBot: Cherry Zhang <cherryyz@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Jeremy Faller <jeremy@golang.org>
2020-05-19[dev.link] cmd/internal/obj: remove asm parameter of NumberSymsCherry Zhang
Now we have ctxt.IsAsm, use that, instead of passing in a parameter. Change-Id: I81dedbe6459424fa9a4c2bfbd9abd83d83f3a107 Reviewed-on: https://go-review.googlesource.com/c/go/+/234492 Run-TryBot: Cherry Zhang <cherryyz@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Jeremy Faller <jeremy@golang.org> Reviewed-by: Than McIntosh <thanm@google.com>
2020-05-19[dev.link] cmd/asm: expand package path if knownCherry Zhang
If the package path is known, pass it to the object file writer so the symbol names are pre-expanded. (We already expand the package path in debug info.) Change-Id: I2b2b71edbb98924cbf3c4f9142b7e109e5b7501a Reviewed-on: https://go-review.googlesource.com/c/go/+/234491 Run-TryBot: Cherry Zhang <cherryyz@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Jeremy Faller <jeremy@golang.org> Reviewed-by: Than McIntosh <thanm@google.com>
2020-05-04[dev.link] cmd: delete old object supportCherry Zhang
We are not going to merge to master until Go 1.16 cycle. The old object support can go now. Change-Id: I93e6f584974c7749d0a0c2e7a96def35134dc566 Reviewed-on: https://go-review.googlesource.com/c/go/+/231918 Run-TryBot: Cherry Zhang <cherryyz@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Than McIntosh <thanm@google.com>
2020-04-24cmd/internal/obj: add IsAsm flagDavid Chase
This allows more exciting changes to compiler-generated assembly language that might not be correct for tricky hand-crafted assembly (e.g., nop padding breaking tables of call or branch instructions). Updates #35881 Change-Id: I842b811796076c160180a364564f2844604df3fb Reviewed-on: https://go-review.googlesource.com/c/go/+/229708 Run-TryBot: David Chase <drchase@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-03-27[dev.link] all: merge branch 'master' into dev.linkCherry Zhang
The only merge conflict is the addition of -spectre flag on master and the addition of -go115newobj flag on dev.link. Resolved trivially. Change-Id: I5b46c2b25e140d6c3d8cb129acbd7a248ff03bb9
2020-03-23[dev.link] cmd/asm, cmd/compile: add back newobj flagCherry Zhang
Add back the newobj flag, renamed to go115newobj, for feature gating. The flag defaults to true. This essentially reverts CL 206398 as well as CL 220060. The old object format isn't working yet. Will fix in followup CLs. Change-Id: I1ace2a9cbb1a322d2266972670d27bda4e24adbc Reviewed-on: https://go-review.googlesource.com/c/go/+/224623 Run-TryBot: Cherry Zhang <cherryyz@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Than McIntosh <thanm@google.com>
2020-03-13cmd/asm, cmd/compile, runtime: add -spectre=ret modeRuss Cox
This commit extends the -spectre flag to cmd/asm and adds a new Spectre mitigation mode "ret", which enables the use of retpolines. Retpolines prevent speculation about the target of an indirect jump or call and are described in more detail here: https://support.google.com/faqs/answer/7625886 Change-Id: I4f2cb982fa94e44d91e49bd98974fd125619c93a Reviewed-on: https://go-review.googlesource.com/c/go/+/222661 Reviewed-by: Keith Randall <khr@golang.org>
2020-03-10[dev.link] cmd/asm: new -p option, changes to DWARF generationThan McIntosh
Adds a new "-p" option to the assembler, for specifying the import path of the package being compiled. DWARF generation is now conditional on having a valid package path -- if we don't know the package path, then don't emit DWARF. This is intended to lay the groundwork for removing the various "patchDWARFname" hacks in the linker. Change-Id: I5f8315c0881791eb8fe1f2ba32f5bb0ae76f6b98 Reviewed-on: https://go-review.googlesource.com/c/go/+/222718 Run-TryBot: Than McIntosh <thanm@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com> Reviewed-by: Jeremy Faller <jeremy@golang.org>
2019-11-11[dev.link] cmd/compile, cmd/asm: delete old object file format supportCherry Zhang
There are more cleanups to do, but I want to keep this CL mostly a pure deletion. Change-Id: Icd2ff0a4b648eb4adf3d29386542617e49620818 Reviewed-on: https://go-review.googlesource.com/c/go/+/206398 Run-TryBot: Cherry Zhang <cherryyz@google.com> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-10-02[dev.link] cmd/compile, cmd/asm: assign index to symbolsCherry Zhang
We are planning to use indices for symbol references, instead of symbol names. Here we assign indices to symbols defined in the package being compiled, and propagate the indices to the dependent packages in the export data. A symbol is referenced by a tuple, (package index, symbol index). Normally, for a given symbol, this index is unique, and the symbol index is globally consistent (but with exceptions, see below). The package index is local to a compilation. For example, when compiling the fmt package, fmt.Println gets assigned index 25, then all packages that reference fmt.Println will refer it as (X, 25) with some X. X is the index for the fmt package, which may differ in different compilations. There are some symbols that do not have clear package affiliation, such as dupOK symbols and linknamed symbols. We cannot give them globally consistent indices. We categorize them as non-package symbols, assign them with package index 1 and a symbol index that is only meaningful locally. Currently nothing will consume the indices. All this is behind a flag, -newobj. The flag needs to be set for all builds (-gcflags=all=-newobj -asmflags=all=-newobj), or none. Change-Id: I18e489c531e9a9fbc668519af92c6116b7308cab Reviewed-on: https://go-review.googlesource.com/c/go/+/196029 Reviewed-by: Than McIntosh <thanm@google.com>
2019-10-01[dev.link] cmd/compile, cmd/asm: use bio.Writer for object file writingCherry Zhang
It is convenient to have a seekable writer. A later CL will make use of Seek. Change-Id: Iba0107ce2975d9a451d97f16aa91a318dd4c90e2 Reviewed-on: https://go-review.googlesource.com/c/go/+/196028 Run-TryBot: Cherry Zhang <cherryyz@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Jeremy Faller <jeremy@golang.org>
2019-05-06cmd/internal/obj: write package path at compile time if possibleCherry Zhang
Currently, when the compiler emits a symbol name in the object file, it uses "". for the package path of the package being compiled. This is then expanded in the linker to the actual package path. With CL 173938, it does not need an allocation if the symbol name does not need expansion. In many cases, the compiler actually knows the package path (through the -p flag), so we could just write it out in compile time, without fixing it up in the linker. This reduces allocations in the linker. In case that the package path is not known (compiler's -p flag is missing, or the object file is generated by the assembler), the linker still does the expansion. This reduces ~100MB allocations (~10% inuse_space) in linking k8s.io/kubernetes/cmd/kube-apiserver on Linux/AMD64. Also makes the linker a little faster: linking cmd/go on Linux/AMD64: Real 1.13 ± 1% 1.11 ± 1% -2.13% (p=0.000 n=10+10) User 1.17 ± 3% 1.14 ± 5% -3.14% (p=0.003 n=10+10) Sys 0.34 ±15% 0.34 ±15% ~ (p=0.986 n=10+10) The caveat is that the object files get slightly bigger. On Linux/AMD64, runtime.a gets 2.1% bigger, cmd/compile/internal/ssa (which has a longer import path) gets 2.8% bigger. This reveals that when building an unnamed plugin (e.g. go build -buildmode=plugin x.go), the go command passes different package paths to the compiler and to the linker. Before this CL there seems nothing obviously broken, but given that the compiler already emits the package's import path in various places (e.g. debug info), I guess it is possible that this leads to some unexpected behavior. Now that the compiler writes the package path in more places, this disagreement actually leads to unresolved symbols. Adjust the go command to use the same package path for both compiling and linking. Change-Id: I19f08981f51db577871c906e08d9e0fd588a2dd8 Reviewed-on: https://go-review.googlesource.com/c/go/+/174657 Reviewed-by: Austin Clements <austin@google.com>
2018-12-11cmd/compile: use innermost line number for -SKeith Randall
When functions are inlined, for instructions in the inlined body, does -S print the location of the call, or the location of the body? Right now, we do the former. I'd like to do the latter by default, it makes much more sense when reading disassembly. With mid-stack inlining enabled in more cases, this quandry will come up more often. The original behavior is still available with -S=2. Some tests use this mode (so they can find assembly generated by a particular source line). This helped me with understanding what the compiler was doing while fixing #29007. Change-Id: Id14a3a41e1b18901e7c5e460aa4caf6d940ed064 Reviewed-on: https://go-review.googlesource.com/c/153241 Reviewed-by: David Chase <drchase@google.com>
2018-11-12cmd/asm: add mode to collect symbol ABIsAustin Clements
This adds a -symabis flag that runs the assembler in a special mode that outputs symbol definition and reference ABIs rather than assembling the code. This uses a fast and somewhat lax parser because the go_asm.h definitions may not be available. For #27539. Change-Id: I248ba0ebab7cc75dcb2a90e82a82eb445da7e88e Reviewed-on: https://go-review.googlesource.com/c/147098 Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: David Chase <drchase@google.com> Reviewed-by: Cherry Zhang <cherryyz@google.com>
2017-11-30compiler,linker: support for DWARF inlined instancesThan McIntosh
Compiler and linker changes to support DWARF inlined instances, see https://go.googlesource.com/proposal/+/HEAD/design/22080-dwarf-inlining.md for design details. This functionality is gated via the cmd/compile option -gendwarfinl=N, where N={0,1,2}, where a value of 0 disables dwarf inline generation, a value of 1 turns on dwarf generation without tracking of formal/local vars from inlined routines, and a value of 2 enables inlines with variable tracking. Updates #22080 Change-Id: I69309b3b815d9fed04aebddc0b8d33d0dbbfad6e Reviewed-on: https://go-review.googlesource.com/75550 Run-TryBot: Than McIntosh <thanm@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: David Chase <drchase@google.com>
2017-04-19cmd/internal/objabi: extract shared functionality from objMatthew Dempsky
Now only cmd/asm and cmd/compile depend on cmd/internal/obj. Changing the assembler backends no longer requires reinstalling cmd/link or cmd/addr2line. There's also now one canonical definition of the object file format in cmd/internal/objabi/doc.go, with a warning to update all three implementations. objabi is still something of a grab bag of unrelated code (e.g., flag and environment variable handling probably belong in a separate "tool" package), but this is still progress. Fixes #15165. Fixes #20026. Change-Id: Ic4b92fac7d0d35438e0d20c9579aad4085c5534c Reviewed-on: https://go-review.googlesource.com/40972 Run-TryBot: Matthew Dempsky <mdempsky@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2017-04-07cmd/internal/obj: eagerly initialize assemblersJosh Bleecher Snyder
CL 38662 changed the x86 assembler to be eagerly initialized, for a concurrent backend. This CL puts in place a proper mechanism for doing so, and switches all architectures to use it. Passes toolstash-check -all. Updates #15756 Change-Id: Id2aa527d3a8259c95797d63a2f0d1123e3ca2a1c Reviewed-on: https://go-review.googlesource.com/39917 Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-04-06cmd/compile: add Prog cache to ProgsJosh Bleecher Snyder
The existing bulk/cached Prog allocator, Ctxt.NewProg, is not concurrency-safe. This CL moves Prog allocation to its clients, the compiler and the assembler. The assembler is so fast and generates so few Progs that it does not need optimization of Prog allocation. I could not generate measureable changes. And even if I could, the assembly is a miniscule portion of build times. The compiler already has a natural place to manage Prog allocation; this CL migrates the Prog cache there. It will be made concurrency-safe in a later CL by partitioning the Prog cache into chunks and assigning each chunk to a different goroutine to manage. This CL does cause a performance degradation when the compiler is invoked with the -S flag (to dump assembly). However, such usage is rare and almost always done manually. The one instance I know of in a test is TestAssembly in cmd/compile/internal/gc, and I did not detect a measurable performance impact there. Passes toolstash-check -all. Minor compiler performance impact. Updates #15756 Performance impact from just this CL: name old time/op new time/op delta Template 213ms ± 4% 213ms ± 4% ~ (p=0.571 n=49+49) Unicode 89.1ms ± 3% 89.4ms ± 3% ~ (p=0.388 n=47+48) GoTypes 581ms ± 2% 584ms ± 3% +0.56% (p=0.019 n=47+48) SSA 6.48s ± 2% 6.53s ± 2% +0.84% (p=0.000 n=47+49) Flate 128ms ± 4% 128ms ± 4% ~ (p=0.832 n=49+49) GoParser 152ms ± 3% 152ms ± 3% ~ (p=0.815 n=48+47) Reflect 371ms ± 4% 371ms ± 3% ~ (p=0.617 n=50+47) Tar 112ms ± 4% 112ms ± 3% ~ (p=0.724 n=49+49) XML 208ms ± 3% 208ms ± 4% ~ (p=0.678 n=49+50) [Geo mean] 284ms 285ms +0.18% name old user-ns/op new user-ns/op delta Template 251M ± 7% 252M ±11% ~ (p=0.704 n=49+50) Unicode 107M ± 7% 108M ± 5% +1.25% (p=0.036 n=50+49) GoTypes 738M ± 3% 740M ± 3% ~ (p=0.305 n=49+48) SSA 8.83G ± 2% 8.86G ± 4% ~ (p=0.098 n=47+50) Flate 146M ± 6% 147M ± 3% ~ (p=0.584 n=48+41) GoParser 178M ± 6% 179M ± 5% +0.93% (p=0.036 n=49+48) Reflect 441M ± 4% 446M ± 7% ~ (p=0.218 n=44+49) Tar 126M ± 5% 126M ± 5% ~ (p=0.766 n=48+49) XML 245M ± 5% 244M ± 4% ~ (p=0.359 n=50+50) [Geo mean] 341M 342M +0.51% Performance impact from this CL combined with its parent: name old time/op new time/op delta Template 213ms ± 3% 214ms ± 4% ~ (p=0.685 n=47+50) Unicode 89.8ms ± 6% 90.5ms ± 6% ~ (p=0.055 n=50+50) GoTypes 584ms ± 3% 585ms ± 2% ~ (p=0.710 n=49+47) SSA 6.50s ± 2% 6.53s ± 2% +0.39% (p=0.011 n=46+50) Flate 128ms ± 3% 128ms ± 4% ~ (p=0.855 n=47+49) GoParser 152ms ± 3% 152ms ± 3% ~ (p=0.666 n=49+49) Reflect 371ms ± 3% 372ms ± 3% ~ (p=0.298 n=48+48) Tar 112ms ± 5% 113ms ± 3% ~ (p=0.107 n=49+49) XML 208ms ± 3% 208ms ± 2% ~ (p=0.881 n=50+49) [Geo mean] 285ms 285ms +0.26% name old user-ns/op new user-ns/op delta Template 254M ± 9% 252M ± 8% ~ (p=0.290 n=49+50) Unicode 106M ± 6% 108M ± 7% +1.44% (p=0.034 n=50+50) GoTypes 741M ± 4% 743M ± 4% ~ (p=0.992 n=50+49) SSA 8.86G ± 2% 8.83G ± 3% ~ (p=0.158 n=47+49) Flate 147M ± 4% 148M ± 5% ~ (p=0.832 n=50+49) GoParser 179M ± 5% 178M ± 5% ~ (p=0.370 n=48+50) Reflect 441M ± 6% 445M ± 7% ~ (p=0.246 n=45+47) Tar 126M ± 6% 126M ± 6% ~ (p=0.815 n=49+50) XML 244M ± 3% 245M ± 4% ~ (p=0.190 n=50+50) [Geo mean] 342M 342M +0.17% Change-Id: I020f1c079d495fbe2e15ccb51e1ea2cc1b5a1855 Reviewed-on: https://go-review.googlesource.com/39634 Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Keith Randall <khr@golang.org>
2017-03-20cmd/internal/obj: convert Debug* Link fields into boolsJosh Bleecher Snyder
Change-Id: I9ac274dbfe887675a7820d2f8f87b5887b1c9b0e Reviewed-on: https://go-review.googlesource.com/38383 Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-03-01cmd/compile, cmd/asm: remove Link.PlistsHeschi Kreinick
Link.Plists never contained more than one Plist, and sometimes none. Passing around the Plist being worked on is straightforward and makes the data flow easier to follow. Change-Id: I79cb30cb2bd3d319fdbb1dfa5d35b27fcb748e5c Reviewed-on: https://go-review.googlesource.com/37169 Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-01-09[dev.inline] cmd/internal/src: replace src.Pos with syntax.PosRobert Griesemer
This replaces the src.Pos LineHist-based position tracking with the syntax.Pos implementation and updates all uses. The LineHist table is not used anymore - the respective code is still there but should be removed eventually. CL forthcoming. Passes toolstash -cmp when comparing to the master repo (with the exception of a couple of swapped assembly instructions, likely due to different instruction scheduling because the line-based sorting has changed; though this is won't affect correctness). The sizes of various important compiler data structures have increased significantly (see the various sizes_test.go files); this is probably the reason for an increase of compilation times (to be addressed). Here are the results of compilebench -count 5, run on a "quiet" machine (no apps running besides a terminal): name old time/op new time/op delta Template 256ms ± 1% 280ms ±15% +9.54% (p=0.008 n=5+5) Unicode 132ms ± 1% 132ms ± 1% ~ (p=0.690 n=5+5) GoTypes 891ms ± 1% 917ms ± 2% +2.88% (p=0.008 n=5+5) Compiler 3.84s ± 2% 3.99s ± 2% +3.95% (p=0.016 n=5+5) MakeBash 47.1s ± 1% 47.2s ± 2% ~ (p=0.841 n=5+5) name old user-ns/op new user-ns/op delta Template 309M ± 1% 326M ± 2% +5.18% (p=0.008 n=5+5) Unicode 165M ± 1% 168M ± 4% ~ (p=0.421 n=5+5) GoTypes 1.14G ± 2% 1.18G ± 1% +3.47% (p=0.008 n=5+5) Compiler 5.00G ± 1% 5.16G ± 1% +3.12% (p=0.008 n=5+5) Change-Id: I241c4246cdff627d7ecb95cac23060b38f9775ec Reviewed-on: https://go-review.googlesource.com/34273 Run-TryBot: Robert Griesemer <gri@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2016-10-05cmd/asm: close file before removeYasuhiro Matsumoto
Windows doesn't remove an open file. Fixes #17345 Change-Id: I283930c7d6eb3bc09ad208191afefe989804ce32 Reviewed-on: https://go-review.googlesource.com/30430 Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-09-09cmd: use obj.GOOS, obj.GOARCH, etcDavid Crawshaw
As cmd/internal/obj is coordinating the definition of GOOS, GOARCH, etc across the compiler and linker, turn its functions into globals and use them everywhere. Change-Id: I5db5addda3c6b6435c37fd5581c7c3d9a561f492 Reviewed-on: https://go-review.googlesource.com/28854 Run-TryBot: David Crawshaw <crawshaw@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2016-08-24cmd/asm, go/build: invoke cmd/asm only once per packageJosh Bleecher Snyder
Prior to this CL, cmd/go invoked cmd/asm once for every assembly file. The exec and cmd/asm startup overhead dwarfed the actual time spent assembling. This CL adds support to cmd/asm to process multiple input files and uses it in cmd/go. This cuts 10% off the wall time for 'go build -a math'. Fixes #15680 Change-Id: I12d2ee2c817207954961dc8f37b8f2b09f835550 Reviewed-on: https://go-review.googlesource.com/27636 Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Rob Pike <r@golang.org>
2016-04-14cmd/internal/obj: remove use of package bioMatthew Dempsky
Also add MustClose and MustWriter to cmd/internal/bio, and use them in cmd/asm. Change-Id: I07f5df3b66c17bc5b2e6ec9c4357d9b653e354e0 Reviewed-on: https://go-review.googlesource.com/21938 Run-TryBot: Matthew Dempsky <mdempsky@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-04-14cmd/internal/obj: change Link.Flag_shared to boolMatthew Dempsky
Change-Id: I9bda2ce6f45fb8292503f86d8f9f161601f222b7 Reviewed-on: https://go-review.googlesource.com/22053 Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>
2016-04-09cmd: remove bio.BufReader and bio.BufWriterDave Cheney
bio.BufReader was never used. bio.BufWriter was used to wrap an existing io.Writer, but the bio.Writer returned would not be seekable, so replace all occurences with bufio.Reader instead. Change-Id: I9c6779e35c63178aa4e104c17bb5bb8b52de0359 Reviewed-on: https://go-review.googlesource.com/21722 Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org> Run-TryBot: Dave Cheney <dave@cheney.net> TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-07cmd: extract obj's Biobuf code into new bio packageMatthew Dempsky
API could still be made more Go-ey. Updates #15165. Change-Id: I514ffceffa43c293ae5d7e5f1e9193fda0098865 Reviewed-on: https://go-review.googlesource.com/21644 Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org> Run-TryBot: Matthew Dempsky <mdempsky@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org>