go/src/cmd/link/internal/loader/loader.go, branch json-isValidNumber-before

cmd/link: don't export all symbols for ELF external linking

2023-01-25T20:45:42Z

Since this may add a large number of --export-dynamic-symbol options, use a response file if the command line gets large. Fixes #53579 Change-Id: Ic226bf372bf1e177a3dae886d1c48f4ce3569c0e Reviewed-on: https://go-review.googlesource.com/c/go/+/414654 Reviewed-by: Michael Pratt Reviewed-by: Joedian Reid Run-TryBot: Ian Lance Taylor Auto-Submit: Ian Lance Taylor Reviewed-by: Than McIntosh TryBot-Result: Gopher Robot

cmd/link: improved host archive debug trace output

2022-11-19T22:39:30Z

When ctxt.Debugvlog > 1, produce additional trace output to describe which object files are being pulled out of host archive libraries and why they were pulled (e.g. which symbol had a reference to something in a library). Intended to make it easier to debug problems with cgo internal linking. Change-Id: Icd64aff244b9145162a00cb51642ef32f26adfba Reviewed-on: https://go-review.googlesource.com/c/go/+/451736 Reviewed-by: Cherry Mui Run-TryBot: Than McIntosh Reviewed-by: David Chase TryBot-Result: Gopher Robot

cmd/compile,cmd/link,runtime: add start line numbers to func metadata

2022-10-14T14:47:12Z

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 == . In runtime.test, 95% of functions have == . 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 Auto-Submit: Michael Pratt Reviewed-by: Matthew Dempsky TryBot-Result: Gopher Robot Reviewed-by: Cherry Mui

cmd/link: refactor usage of SymLocalentry helper functions

2022-09-27T17:29:05Z

PPC64 ELFv2 uses the st_other field of a symbol to specify an offset from the global entry point to its local entry point. Similarly, some values (i.e 1) may also require additional linker support which is missing today. For now, generate an error if we encounter unsupported local entry values on PPC64, and update the Localentry values to use bytes, not 32b instruction words. Similarly, ELFv2 1.5 also updates the wording of values 2-6. They now map to a specific number of bytes. Change-Id: Id1b71c3b0fea982bdcfb7eac91d9f93e04ae43f9 Reviewed-on: https://go-review.googlesource.com/c/go/+/431876 TryBot-Result: Gopher Robot Reviewed-by: Cherry Mui Run-TryBot: Paul Murphy Reviewed-by: Dmitri Shuralyov

cmd/link: fix trampolines breaking DWARF line info

2022-08-11T14:11:53Z

When trampolines are needed (e.g. Darwin ARM64), the DWARF LPT (Line Program Table - see DWARF section 6.1) generation fails because the replacement symbols are marked as external symbols and skipped during the DWARF LPT generation phase. Fixes #54320 Change-Id: I6c93f5378f50e5edf30d5121402a48214abb1ce2 GitHub-Last-Rev: 085bbc55dbc95d55456cc2acc46a0d02416c2848 GitHub-Pull-Request: golang/go#54321 Reviewed-on: https://go-review.googlesource.com/c/go/+/422154 Reviewed-by: Cherry Mui Run-TryBot: Than McIntosh Reviewed-by: Than McIntosh TryBot-Result: Gopher Robot

all: use ":" for compiler generated symbols

2022-08-09T11:28:56Z

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 Run-TryBot: Cuong Manh Le Reviewed-by: Cherry Mui TryBot-Result: Gopher Robot

all: use io.Seek* instead of deprecated os.SEEK_*

2022-08-08T17:01:54Z

These are available since Go 1.7. The version used for bootstrap is Go 1.17 for Go 1.20. For #44505 Change-Id: I497c9f617baefdeb273cd115b08b6e31bd10aad2 Reviewed-on: https://go-review.googlesource.com/c/go/+/421634 Reviewed-by: Than McIntosh Run-TryBot: Tobias Klauser Reviewed-by: Brad Fitzpatrick TryBot-Result: Gopher Robot Reviewed-by: Dmitri Shuralyov

cmd/link: remove name expansion logic

2022-05-12T18:45:57Z

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 TryBot-Result: Gopher Robot Run-TryBot: Cherry Mui

cmd/link: preserve symbol attributes when cloning to external

2022-04-15T19:02:54Z

There are some symbol attributes that are encoded in the object file. Currently, they are lost when cloning a symbol to external. Copy them over. Also delete CopyAttributes as it is no longer called anywhere. Change-Id: I1497e3223a641704bf35aa3e904dd0eda2f8ec3e Reviewed-on: https://go-review.googlesource.com/c/go/+/400574 Run-TryBot: Cherry Mui TryBot-Result: Gopher Robot Reviewed-by: Than McIntosh

all: gofmt main repo

2022-04-11T16:34:30Z

[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 Reviewed-by: Ian Lance Taylor