From 1cf6e31f0d03bb3571cfe034f2d909591a0ae453 Mon Sep 17 00:00:00 2001 From: Cherry Mui Date: Sat, 3 Aug 2024 14:20:58 -0400 Subject: cmd/compile: add basic wasmexport support 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 Reviewed-by: Randy Reddig Reviewed-by: David Chase LUCI-TryBot-Result: Go LUCI --- src/cmd/compile/internal/noder/reader.go | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) (limited to 'src/cmd/compile/internal/noder/reader.go') diff --git a/src/cmd/compile/internal/noder/reader.go b/src/cmd/compile/internal/noder/reader.go index ff44adedb4..1dd2e09b0d 100644 --- a/src/cmd/compile/internal/noder/reader.go +++ b/src/cmd/compile/internal/noder/reader.go @@ -1132,15 +1132,22 @@ func (r *reader) funcExt(name *ir.Name, method *types.Sym) { r.linkname(name) if buildcfg.GOARCH == "wasm" { - xmod := r.String() - xname := r.String() + importmod := r.String() + importname := r.String() + exportname := r.String() - if xmod != "" && xname != "" { + if importmod != "" && importname != "" { fn.WasmImport = &ir.WasmImport{ - Module: xmod, - Name: xname, + Module: importmod, + Name: importname, } } + if exportname != "" { + if method != nil { + base.ErrorfAt(fn.Pos(), 0, "cannot use //go:wasmexport on a method") + } + fn.WasmExport = &ir.WasmExport{Name: exportname} + } } if r.Bool() { -- cgit v1.3