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2023-02-06cmd/internal/obj: flag init functions in object fileThan McIntosh
Introduce a flag in the object file indicating whether a given function corresponds to a compiler-generated (not user-written) init function, such as "os.init" or "syscall.init". Add code to the compiler to fill in the correct value for the flag, and add support to the loader package in the linker for testing the flag. The new loader API is currently unused, but will be needed in the next CL in this stack. Updates #2559. Updates #36021. Updates #14840. Change-Id: Iea7ad2adda487e4af7a44f062f9817977c53b394 Reviewed-on: https://go-review.googlesource.com/c/go/+/463855 Reviewed-by: Cherry Mui <cherryyz@google.com> Run-TryBot: Than McIntosh <thanm@google.com> TryBot-Result: Gopher Robot <gobot@golang.org>
2023-01-20all: fix typos in go file commentsMarcel Meyer
This is the second round to look for spelling mistakes. This time the manual sifting of the result list was made easier by filtering out capitalized and camelcase words. grep -r --include '*.go' -E '^// .*$' . | aspell list | grep -E -x '[A-Za-z]{1}[a-z]*' | sort | uniq This PR will be imported into Gerrit with the title and first comment (this text) used to generate the subject and body of the Gerrit change. Change-Id: Ie8a2092aaa7e1f051aa90f03dbaf2b9aaf5664a9 GitHub-Last-Rev: fc2bd6e0c51652f13a7588980f1408af8e6080f5 GitHub-Pull-Request: golang/go#57737 Reviewed-on: https://go-review.googlesource.com/c/go/+/461595 Auto-Submit: Ian Lance Taylor <iant@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@google.com> Run-TryBot: Ian Lance Taylor <iant@google.com> Reviewed-by: Robert Griesemer <gri@google.com>
2022-11-15cmd/internal/goobj: use testenv.Command instead of exec.Command in testsBryan C. Mills
testenv.Command sets a default timeout based on the test's deadline and sends SIGQUIT (where supported) in case of a hang. Change-Id: I464dc34b50f3360123aca9e8666df9799c15e457 Reviewed-on: https://go-review.googlesource.com/c/go/+/450701 Run-TryBot: Bryan Mills <bcmills@google.com> Auto-Submit: Bryan Mills <bcmills@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@google.com>
2022-11-10cmd/internal/obj: reduce allocations in object file writingCherry Mui
Some object file writer functions are structured like, having a local variable, setting fields, then passing it to a Write method which eventually calls io.Writer.Write. As the Write call is an interface call it escapes the parameter, which in turn causes the local variable to be heap allocated. To reduce allocation, use pre-allocated scratch space instead. Reduce number of allocations in the compiler: name old allocs/op new allocs/op delta Template 679k ± 0% 644k ± 0% -5.17% (p=0.000 n=20+20) Unicode 603k ± 0% 581k ± 0% -3.67% (p=0.000 n=20+20) GoTypes 3.83M ± 0% 3.63M ± 0% -5.30% (p=0.000 n=20+20) Compiler 353k ± 0% 342k ± 0% -3.09% (p=0.000 n=18+19) SSA 31.4M ± 0% 30.4M ± 0% -3.02% (p=0.000 n=20+20) Flate 397k ± 0% 373k ± 0% -5.92% (p=0.000 n=20+18) GoParser 777k ± 0% 735k ± 0% -5.37% (p=0.000 n=20+20) Reflect 2.07M ± 0% 1.90M ± 0% -7.89% (p=0.000 n=18+20) Tar 605k ± 0% 568k ± 0% -6.26% (p=0.000 n=19+16) XML 801k ± 0% 766k ± 0% -4.36% (p=0.000 n=20+20) [Geo mean] 1.18M 1.12M -5.02% Change-Id: I9d02a72e459e645527196ac54b6ee643a5ea6bd3 Reviewed-on: https://go-review.googlesource.com/c/go/+/449637 TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: David Chase <drchase@google.com> Run-TryBot: Cherry Mui <cherryyz@google.com>
2022-10-14cmd/compile,cmd/link,runtime: add start line numbers to func metadataMichael Pratt
This adds the function "start line number" to runtime._func and runtime.inlinedCall objects. The "start line number" is the line number of the func keyword or TEXT directive for assembly. Subtracting the start line number from PC line number provides the relative line offset of a PC from the the start of the function. This helps with source stability by allowing code above the function to move without invalidating samples within the function. Encoding start line rather than relative lines directly is convenient because the pprof format already contains a start line field. This CL uses a straightforward encoding of explictly including a start line field in every _func and inlinedCall. It is possible that we could compress this further in the future. e.g., functions with a prologue usually have <line of PC 0> == <start line>. In runtime.test, 95% of functions have <line of PC 0> == <start line>. According to bent, this is geomean +0.83% binary size vs master and -0.31% binary size vs 1.19. Note that //line directives can change the file and line numbers arbitrarily. The encoded start line is as adjusted by //line directives. Since this can change in the middle of a function, `line - start line` offset calculations may not be meaningful if //line directives are in use. For #55022. Change-Id: Iaabbc6dd4f85ffdda294266ef982ae838cc692f6 Reviewed-on: https://go-review.googlesource.com/c/go/+/429638 Run-TryBot: Michael Pratt <mpratt@google.com> Auto-Submit: Michael Pratt <mpratt@google.com> Reviewed-by: Matthew Dempsky <mdempsky@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Cherry Mui <cherryyz@google.com>
2022-09-29cmd: fix a few function names on commentscui fliter
Change-Id: Ia0896bd1edf2558821244fecd1c297b599472f47 GitHub-Last-Rev: cfd1e1091a064cdc38469c02c6c013635d7d437b GitHub-Pull-Request: golang/go#55944 Reviewed-on: https://go-review.googlesource.com/c/go/+/436637 Reviewed-by: Ian Lance Taylor <iant@google.com> Auto-Submit: Ian Lance Taylor <iant@google.com> Run-TryBot: Ian Lance Taylor <iant@google.com> Reviewed-by: Dmitri Shuralyov <dmitshur@google.com> TryBot-Result: Gopher Robot <gobot@golang.org>
2022-09-20all: replace package ioutil with os and io in srcAndy Pan
For #45557 Change-Id: I56824135d86452603dd4ed4bab0e24c201bb0683 Reviewed-on: https://go-review.googlesource.com/c/go/+/426257 Run-TryBot: Ian Lance Taylor <iant@google.com> Auto-Submit: Ian Lance Taylor <iant@google.com> Run-TryBot: Andy Pan <panjf2000@gmail.com> Reviewed-by: Cherry Mui <cherryyz@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@google.com>
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>
2022-05-20cmd/compile: intercept string compares in libFuzzer modeKhaled Yakdan
IR string compares as well as calls to string comparison functions such as `strings.EqualFold` are intercepted and the corresponding libFuzzer callbacks are invoked with the corresponding arguments. As a result, the compared strings will be added to libFuzzer’s table of recent compares, which feeds future mutations performed by the fuzzer and thus allow it to reach into branches guarded by string comparisons. The list of methods to intercept is maintained in `cmd/compile/internal/walk/expr.go` and can easily be extended to cover more standard library functions in the future. Change-Id: I5c8b89499c4e19459406795dea923bf777779c51 GitHub-Last-Rev: 6b8529b55561faf57ea59cb7cff1caf8c9c94ecd GitHub-Pull-Request: golang/go#51319 Reviewed-on: https://go-review.googlesource.com/c/go/+/387335 Reviewed-by: Keith Randall <khr@golang.org> Reviewed-by: Michael Knyszek <mknyszek@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Keith Randall <khr@google.com> Run-TryBot: Keith Randall <khr@golang.org>
2022-05-12cmd/link: remove name expansion logicCherry Mui
Now both the compiler and the assembler require the -p flag and emit full package path in symbol names, we no longer need to do the name expansion in the linker. Delete it. Change-Id: I771d4d97987a0a17414881b52806d600ef4cc351 Reviewed-on: https://go-review.googlesource.com/c/go/+/404300 Reviewed-by: Than McIntosh <thanm@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Run-TryBot: Cherry Mui <cherryyz@google.com>
2022-05-11cmd/asm: require -p flagCherry Mui
CL 391014 requires the compiler to be invoked with the -p flag, to specify the package path. Later, CL 394217 makes the compiler to produce an unlinkable object file, so "go tool compile x.go" can still be used on the command line. This CL does the same for the assembler, requiring -p, otherwise generating an unlinkable object. No special case for the main package, as the main package cannot be only assembly code, and there is no way to tell if it is the main package from an assembly file. Now we guarantee that we always have an expanded package path in the object file. A later CL will delete the name expansion code in the linker. Change-Id: I8c10661aaea2ff794614924ead958d80e7e2487d Reviewed-on: https://go-review.googlesource.com/c/go/+/404298 Run-TryBot: Cherry Mui <cherryyz@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Than McIntosh <thanm@google.com> Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2022-05-11cmd/internal/obj: add a flag to not write referenced symbol names in object fileCherry Mui
The Go object file references (some of) symbols from other packages by indices, not by names. The linker doesn't need the symbol names to do the linking. The names are included in the object file so it is self-contained and tools (objdump, nm) can read the referenced symbol names. Including the names increases object file size. Add a flag to disable it on demand (off by default). Change-Id: I143a0eb656997497c750b8eb1541341b2aee8f30 Reviewed-on: https://go-review.googlesource.com/c/go/+/404297 TryBot-Result: Gopher Robot <gobot@golang.org> Run-TryBot: Cherry Mui <cherryyz@google.com> Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2022-05-05cmd: use 128-bit SHA256 & encode in base64 for content hashesRuss Cox
We used to use SHA1 for content hashes, but CL 402595 changed all the “don't care” hashes to cmd/internal/notsha256 (negated SHA256). This made object files a little bit bigger: fmt.a on my Mac laptop grows from 910678 to 937612 bytes (+3%). To remove that growth, truncate the hash we use for these purposes to 128 bits (half a SHA256), and also use base64 instead of hex for encoding it when a string form is needed. This brings fmt.a down to 901706 bytes (-1% from original, -4% from current). Change-Id: Id81da1cf3ee85ed130b3cda73aa697d8c0053a62 Reviewed-on: https://go-review.googlesource.com/c/go/+/404294 Auto-Submit: 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>
2022-04-29[dev.boringcrypto] cmd: use notsha256 instead of md5, sha1, sha256Russ Cox
When we add GOEXPERIMENT=boringcrypto, the bootstrap process will not converge if the compiler itself depends on the boringcrypto cgo-based implementations of sha1 and sha256. Using notsha256 avoids boringcrypto and makes bootstrap converge. Removing md5 is not strictly necessary but it seemed worthwhile to be consistent. For #51940. Change-Id: Iba649507e0964d1a49a1d16e463dd23c4e348f14 Reviewed-on: https://go-review.googlesource.com/c/go/+/402595 Reviewed-by: Ian Lance Taylor <iant@google.com> Run-TryBot: Russ Cox <rsc@golang.org> 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>
2022-04-01all: fix various doc comment formatting nitsRuss Cox
A run of lines that are indented with any number of spaces or tabs format as a <pre> block. This commit fixes various doc comments that format badly according to that (standard) rule. For example, consider: // - List item. // Second line. // - Another item. Because the - lines are unindented, this is actually two paragraphs separated by a one-line <pre> block. This CL rewrites it to: // - List item. // Second line. // - Another item. Today, that will format as a single <pre> block. In a future release, we hope to format it as a bulleted list. Various other minor fixes as well, all in preparation for reformatting. For #51082. Change-Id: I95cf06040d4186830e571cd50148be3bf8daf189 Reviewed-on: https://go-review.googlesource.com/c/go/+/384257 Trust: Russ Cox <rsc@golang.org> Run-TryBot: Russ Cox <rsc@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org> TryBot-Result: Gopher Robot <gobot@golang.org>
2022-03-22cmd/compile, cmd/link: produce unlinkable object when compile without -pCherry Mui
CL 391014 requires the compiler to be invoked with the -p flag, to specify the package path. People are used to run "go tool compile" from the command line with the -p flag. This is mostly for simple testing, or debugging the compiler. The produced object file is almost never intended to be linked. This CL makes the compiler allow "go tool compile" without the -p flag again. It will produce an unlinkable object. If the linker sees such an object it will error out. Change-Id: I7bdb162c3cad61dadd5c456d903b92493a3df20f Reviewed-on: https://go-review.googlesource.com/c/go/+/394217 Trust: Cherry Mui <cherryyz@google.com> Reviewed-by: Matthew Dempsky <mdempsky@google.com> Run-TryBot: Cherry Mui <cherryyz@google.com> TryBot-Result: Gopher Robot <gobot@golang.org>
2021-10-28cmd/internal/goobj: bump version numberCherry Mui
There have a few updates to the Go object file in this cycle (e.g. FuncInfo format change, some changes in constant values), and it is not compatible with the old tools. Bump up the version number. Change-Id: Id176979b139c76ded2c50f2678eb313934326d6f Reviewed-on: https://go-review.googlesource.com/c/go/+/359483 Trust: Cherry Mui <cherryyz@google.com> Run-TryBot: Cherry Mui <cherryyz@google.com> Reviewed-by: Than McIntosh <thanm@google.com> TryBot-Result: Go Bot <gobot@golang.org>
2021-10-20cmd/internal/goobj: minor dead code cleanupThan McIntosh
Remove a bit of dead code from the Go object file reader (io.ReaderAt no longer needed in goobj.Reader). Change-Id: I04150d37fb90b59c9dbe930878d4dd21cdcd7ca7 Reviewed-on: https://go-review.googlesource.com/c/go/+/357309 Trust: Than McIntosh <thanm@google.com> Run-TryBot: Than McIntosh <thanm@google.com> Reviewed-by: Cherry Mui <cherryyz@google.com> TryBot-Result: Go Bot <gobot@golang.org>
2021-09-29cmd/internal/goobj, cmd/link: remove funcdataoffCherry Mui
FUNCDATA is always a symbol reference with 0 offset. Assert the offset is 0 and remove funcdataoff. Change-Id: I326815365c9db5aeef6b869df5d78a9957bc16a6 Reviewed-on: https://go-review.googlesource.com/c/go/+/352894 Trust: Cherry Mui <cherryyz@google.com> Reviewed-by: Than McIntosh <thanm@google.com>
2021-09-29cmd/link: access pcdata via aux symbolsCherry Mui
Pcdata are now separate aux symbols. Read them from aux, instead of using funcinfo. Now we can remove pcdata fields from funcinfo. Change-Id: Ie65e3962edecc0f39127a5f6963dc59d1f141e67 Reviewed-on: https://go-review.googlesource.com/c/go/+/352893 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>
2021-09-28cmd/internal/objfile: use aux symbol for pcdata referencesCherry Mui
Pcdata are now separate aux symbols. Read them from aux, instead of using funcinfo. Change-Id: Ib3e4b5cff1e3329d0600504a8829a969a9c9f517 Reviewed-on: https://go-review.googlesource.com/c/go/+/352612 Trust: Cherry Mui <cherryyz@google.com> Trust: Josh Bleecher Snyder <josharian@gmail.com> Run-TryBot: Cherry Mui <cherryyz@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2021-09-28cmd/internal/goobj: remove Pcdata from object fileCherry Mui
As of CL 247399 we use separate symbols for PCDATA. There is no more need for writing PCDATA directly into the object file as a separate block. Change-Id: I942d1a372540415e0cc07fb2a01f79718a264142 Reviewed-on: https://go-review.googlesource.com/c/go/+/352610 Trust: Cherry Mui <cherryyz@google.com> Trust: Josh Bleecher Snyder <josharian@gmail.com> Run-TryBot: Cherry Mui <cherryyz@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
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>
2021-09-20cmd/link: generate DIE for types referenced only through dictionariesAlessandro Arzilli
Generate debug_info entries for types that are only referenced through dictionaries. Change-Id: Ic36c2e6d9588ec6746793bb213c2dc0e17a8a850 Reviewed-on: https://go-review.googlesource.com/c/go/+/350532 Run-TryBot: Alessandro Arzilli <alessandro.arzilli@gmail.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Dan Scales <danscales@google.com> Reviewed-by: Than McIntosh <thanm@google.com> Trust: Dan Scales <danscales@google.com> Trust: David Chase <drchase@google.com>
2021-06-03[dev.typeparams] cmd/internal/goobj: add duffzero/duffcopy to builtin listCherry Mui
duffzero and duffcopy are commonly referenced functions. Add them to builtin list, so they are referenced by index, not by name. Also change gcWriteBarrier to ABIInternal, which is changed in CL 266638. Regenerate the file. Change-Id: If8550d9ed300ac2be930a7c58657a9cf1933ac1d Reviewed-on: https://go-review.googlesource.com/c/go/+/324250 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>
2021-04-16internal/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>
2021-03-05cmd/internal/goobj: store relocation type as uint16Cherry Zhang
Currently, relocation type is stored as uint8 in object files, as Go relocations do not exceed 255. In the linker, however, it is used as a 16-bit type, because external relocations can exceed 255. The linker has to store the extra byte in a side table. This complicates many things. Just store it as uint16 in object files. This simplifies things, with a small cost of increasing the object file sizes. before after hello.o 1672 1678 runtime.a 7927784 8056194 Change-Id: I313cf44ad0b8b3b76e35055ae55d911ff35e3158 Reviewed-on: https://go-review.googlesource.com/c/go/+/268477 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>
2021-03-05cmd/internal/goobj: regenerate builtin listCherry Zhang
Change-Id: Ib8cb5f90e084838f00ecba78641bbb5d48ecac32 Reviewed-on: https://go-review.googlesource.com/c/go/+/297931 Trust: Cherry Zhang <cherryyz@google.com> Reviewed-by: David Chase <drchase@google.com>
2021-02-24cmd/internal/goobj: add test case for object file readerThan McIntosh
Add test in which a input Go object file contains a very large number of relocations (more than 1<<20). Updates #41621. Change-Id: If1ebf3c4fefbf55ddec4e05c5299e7c48fc697d8 Reviewed-on: https://go-review.googlesource.com/c/go/+/278493 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>
2021-02-24docs: fix spellingJohn Bampton
Change-Id: Ib689e5793d9cb372e759c4f34af71f004010c822 GitHub-Last-Rev: d63798388e5dcccb984689b0ae39b87453b97393 GitHub-Pull-Request: golang/go#44259 Reviewed-on: https://go-review.googlesource.com/c/go/+/291949 Reviewed-by: Emmanuel Odeke <emmanuel@orijtech.com> Reviewed-by: Ian Lance Taylor <iant@golang.org> Trust: Matthew Dempsky <mdempsky@google.com> Trust: Robert Griesemer <gri@golang.org>
2021-02-20all: go fmt std cmd (but revert vendor)Russ Cox
Make all our package sources use Go 1.17 gofmt format (adding //go:build lines). Part of //go:build change (#41184). See https://golang.org/design/draft-gobuild Change-Id: Ia0534360e4957e58cd9a18429c39d0e32a6addb4 Reviewed-on: https://go-review.googlesource.com/c/go/+/294430 Trust: Russ Cox <rsc@golang.org> Run-TryBot: Russ Cox <rsc@golang.org> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com> Reviewed-by: Ian Lance Taylor <iant@golang.org>
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>
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>
2020-12-16cmd/internal/goobj: fix buglet in object file readerThan McIntosh
The code in the new (introduced in 1.15) Go object file reader was casting a pointer-mmaped-memory into a large array prior to performing a read of the relocations section: return (*[1<<20]Reloc)(unsafe.Pointer(&r.b[off]))[:n:n] For very large object files, this artificial array isn't large enough (that is, there are more than 1048576 relocs to read), so update the code to use a larger artifical array size. Fixes #41621. Change-Id: Ic047c8aef4f8a3839f2e7e3594bce652ebd6bd5b Reviewed-on: https://go-review.googlesource.com/c/go/+/278492 Run-TryBot: Than McIntosh <thanm@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com> Reviewed-by: Jeremy Faller <jeremy@golang.org> Trust: Than McIntosh <thanm@google.com>
2020-09-11[dev.link] all: merge branch 'master' into dev.linkCherry Zhang
Clean merge. Change-Id: Ib773b0bc00fd99d494f9331c3613bcc8285e48e3
2020-08-26cmd/internal/objabi: delete doc.goCherry Zhang
cmd/internal/objabi/doc.go has comments decribing the (old) object file format. But cmd/internal/objabi has nothing to do with object files, and never did. Delete. Move some comment to cmd/internal/goobj, where the (new) object file format is actually defined, and update to reflect the current status. Change-Id: Ied96089df4be35e5d259a572ed60ee00f2cd0d1d Reviewed-on: https://go-review.googlesource.com/c/go/+/249958 Reviewed-by: Than McIntosh <thanm@google.com>
2020-08-13[dev.link] cmd/link, cmd/compile: create content addressable pcdata symsJeremy Faller
Switch pcdata over to content addressable symbols. This is the last step before removing these from pclntab_old. No meaningful benchmarks changes come from this work. Change-Id: I3f74f3d6026a278babe437c8010e22992c92bd89 Reviewed-on: https://go-review.googlesource.com/c/go/+/247399 Reviewed-by: Austin Clements <austin@google.com> 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>
2020-08-10[dev.link] cmd/internal/archive: rename from goobjCherry Zhang
Rename cmd/internal/goobj package to cmd/internal/archive. This is in preparation of a refactoring of object and archive file reading packages. With this CL, the cmd/internal/archive contains logic about reading Go object files. This will be moved to other places in later CLs. Change-Id: Ided7287492a4766183d6e49be840a7f361504d1d Reviewed-on: https://go-review.googlesource.com/c/go/+/246442 Run-TryBot: Cherry Zhang <cherryyz@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Austin Clements <austin@google.com> Reviewed-by: Jeremy Faller <jeremy@golang.org>
2020-08-10[dev.link] use per package filenames to build pclntabJeremy Faller
In order to prevent renumbering of filenames in pclntab generation, use the per-package file list (previously only used for DWARF generation) as file-indices. This is the largest step to eliminate renumbering of filenames in pclntab. Note, this is probably not the final state of the file table within the object file. In this form, the linker loads all filenames for all objects. I'll move to storing the filenames as regular string symbols,and defaulting all string symbols to using the larger hash value to make generation of pcln simplest, and most memory friendly. Change-Id: I23daafa3f4b4535076e23100200ae0e7163aafe0 Reviewed-on: https://go-review.googlesource.com/c/go/+/245485 Run-TryBot: Jeremy Faller <jeremy@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Austin Clements <austin@google.com>
2020-08-03[dev.link] cmd/internal/goobj: delete old object file readerCherry Zhang
Change-Id: Ieebab205e2cea2b4665c830b7424d543812787ff Reviewed-on: https://go-review.googlesource.com/c/go/+/246441 Reviewed-by: Austin Clements <austin@google.com> Reviewed-by: Jeremy Faller <jeremy@golang.org>
2020-07-16[dev.link] cmd/internal/goobj2, cmd/link: use short hash function for short ↵Cherry Zhang
symbols For symbols of size 8 bytes or below, we can map them to 64-bit hash values using the identity function. There is no need to use longer and more expensive hash functions. For them, we introduce another pseudo-package, PkgIdxHashed64. It is like PkgIdxHashed except that the hash function is different. Note that the hash value is not affected with trailing zeros, e.g. "A" and "A\0\0\0" have the same hash value. This allows deduplicating a few more symbols. When deduplicating them, we need to keep the longer one. Change-Id: Iad0c2e9e569b6a59ca6a121fb8c8f0c018c6da03 Reviewed-on: https://go-review.googlesource.com/c/go/+/242362 Reviewed-by: Jeremy Faller <jeremy@golang.org>
2020-07-16[dev.link] cmd/internal/goobj2, cmd/link: add content addressable symbolsCherry Zhang
This CL introduces content-addressable symbols (a.k.a. hashed symbols) to object files. Content-addressable symbols are identified and referenced by their content hashes, instead of by names. In the object file, a new pseudo-package index PkgIdxHashed is introduced, for content-addressable symbols, and a new block is added to store their hashes. The hashes are used by the linker to identify and deduplicate the symbols. For now, we only support content-addressable symbols that are always locally defined (i.e. no cross-package references). As a proof of concept, make string constant symbols content- addressable. Change-Id: Iaf53efd74c0ffb54fa95f784628cc84e95844536 Reviewed-on: https://go-review.googlesource.com/c/go/+/242079 Run-TryBot: Cherry Zhang <cherryyz@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Jeremy Faller <jeremy@golang.org>
2020-06-05[dev.link] all: merge branch 'master' into dev.linkCherry Zhang
Merge conflicts are mostly recently changed nm/objdump output format and its tests. Resolved easily (mostly just using the format on master branch). Change-Id: I99d8410a9a02947ecf027d9cae5762861562baf5
2020-06-03cmd/internal/goobj2: add referenced symbol names to object fileCherry Zhang
Currently, for symbols defined in other packages and referenced by index, we don't record its name in the object file, as the linker doesn't need the name, only the index. As a consequence, tools like objdump and nm also don't know the referenced symbol names and cannot dump it properly. This CL adds referenced symbol names to the object file. So the object file is self-contained. And tools can retrieve referenced symbol names properly. Tools now should work as good for new object files as for old object files. Fixes #38875. Change-Id: I16c685c1fd83273ab1faef474e19acf4af46396f Reviewed-on: https://go-review.googlesource.com/c/go/+/236168 Reviewed-by: Austin Clements <austin@google.com> Reviewed-by: Jeremy Faller <jeremy@golang.org> Reviewed-by: Than McIntosh <thanm@google.com>
2020-06-03Revert "cmd/internal/goobj: add index to symbol name for indexed symbols"Cherry Zhang
This reverts CL 229246. For new indexed object files, in CL 229246 we added symbol index to tools (nm, objdump) output. This affects external tools that parse those outputs. And the added index doesn't look very nice. In this release we take it out. For future releases we may introduce a flag to tools (nm, objdump) and optionally dump the symbol index. For refererenced (not defined) indexed symbols, currently the symbol is still referenced only by index, not by name. The next CL will make the object file self-contained, so tools can dump the symbol names properly (as before). For #38875. Change-Id: I07375e85a8e826e15c82fa452d11f0eaf8535a00 Reviewed-on: https://go-review.googlesource.com/c/go/+/236167 Reviewed-by: Than McIntosh <thanm@google.com> Reviewed-by: Jeremy Faller <jeremy@golang.org>
2020-05-14[dev.link] cmd/internal/goobj2, cmd/link: change data type for local ↵Cherry Zhang
object/index representation Use uint32 consistently for local index (this is what the object file uses). Use a index, instead of a pointer, to refer to the object file. This reduces memory usage and GC work. This reduces some allocations. Linking cmd/compile, name old alloc/op new alloc/op delta Loadlib_GC 19.9MB ± 0% 16.9MB ± 0% -15.33% (p=0.008 n=5+5) name old live-B new live-B delta Loadlib_GC 12.6M ± 0% 11.3M ± 0% -9.97% (p=0.008 n=5+5) Change-Id: I20ce60bbb6d31abd2e9e932bdf959e2ae840ab98 Reviewed-on: https://go-review.googlesource.com/c/go/+/233779 Run-TryBot: Cherry Zhang <cherryyz@google.com> TryBot-Result: Gobot Gobot <gobot@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>
2020-04-24[dev.link] cmd/internal/goobj2: add index fingerprint to object fileCherry Zhang
The new object files use indices for symbol references, instead of names. Fundamental to the design, it requires that the importing and imported packages have consistent view of symbol indices. The Go command should already ensure this, when using "go build". But in case it goes wrong, it could lead to obscure errors like run-time crashes. It would be better to check the index consistency at build time. To do that, we add a fingerprint to each object file, which is a hash of symbol indices. In the object file it records the fingerprints of all imported packages, as well as its own fingerprint. At link time, the linker checks that a package's fingerprint matches the fingerprint recorded in the importing packages, and issue an error if they don't match. This CL does the first part: introducing the fingerprint in the object file, and propagating fingerprints through importing/exporting by the compiler. It is not yet used by the linker. Next CL will do. Change-Id: I0aa372da652e4afb11f2867cb71689a3e3f9966e Reviewed-on: https://go-review.googlesource.com/c/go/+/229617 Reviewed-by: Austin Clements <austin@google.com> Reviewed-by: Than McIntosh <thanm@google.com> Reviewed-by: Jeremy Faller <jeremy@golang.org>
generated by cgit v1.3 (git 2.53.0) at 2026-04-15 20:09:41 +0000