From 453a1d35c315cb4b2519c86e4d53a7699bbcdea2 Mon Sep 17 00:00:00 2001
From: Randy Reddig <randy.reddig@fastly.com>
Date: Sat, 5 Oct 2024 02:36:47 +0200
Subject: [PATCH] compiler, runtime: enable go:wasmexport for wasip2 (#4499)

* compiler: prefer go:wasmexport over go:export

* runtime, targets/wasip2: enable -buildmode=c-shared for wasip2

* runtime: rename import from wasi_run to wasiclirun (PR feedback)
---
 compiler/symbol.go                             |  7 +++++++
 ...untime_wasm_wasip2.go => runtime_wasip2.go} | 18 +++++++++++-------
 src/runtime/runtime_wasmentry.go               |  2 +-
 targets/wasip2.json                            |  1 +
 4 files changed, 20 insertions(+), 8 deletions(-)
 rename src/runtime/{runtime_wasm_wasip2.go => runtime_wasip2.go} (75%)

diff --git a/compiler/symbol.go b/compiler/symbol.go
index 4a080cbbc..216aa6eec 100644
--- a/compiler/symbol.go
+++ b/compiler/symbol.go
@@ -389,6 +389,13 @@ func (c *compilerContext) parsePragmas(info *functionInfo, f *ssa.Function) {
 			}
 		}
 	}
+
+	// If both //go:wasmexport and //go:export or //export are declared,
+	// only honor go:wasmexport.
+	if info.wasmExport != "" {
+		// TODO: log warning?
+		info.exported = false
+	}
 }
 
 // Check whether this function can be used in //go:wasmimport or
diff --git a/src/runtime/runtime_wasm_wasip2.go b/src/runtime/runtime_wasip2.go
similarity index 75%
rename from src/runtime/runtime_wasm_wasip2.go
rename to src/runtime/runtime_wasip2.go
index 57e6623d3..ba8f52100 100644
--- a/src/runtime/runtime_wasm_wasip2.go
+++ b/src/runtime/runtime_wasip2.go
@@ -6,18 +6,19 @@ import (
 	"unsafe"
 
 	"internal/wasi/cli/v0.2.0/environment"
+	wasiclirun "internal/wasi/cli/v0.2.0/run"
 	monotonicclock "internal/wasi/clocks/v0.2.0/monotonic-clock"
+
+	"internal/cm"
 )
 
 type timeUnit int64
 
-//export wasi:cli/run@0.2.0#run
-func __wasi_cli_run_run() uint32 {
-	// These need to be initialized early so that the heap can be initialized.
-	heapStart = uintptr(unsafe.Pointer(&heapStartSymbol))
-	heapEnd = uintptr(wasm_memory_size(0) * wasmPageSize)
-	run()
-	return 0
+func init() {
+	wasiclirun.Exports.Run = func() cm.BoolResult {
+		callMain()
+		return false
+	}
 }
 
 var args []string
@@ -51,3 +52,6 @@ func sleepTicks(d timeUnit) {
 func ticks() timeUnit {
 	return timeUnit(monotonicclock.Now())
 }
+
+func beforeExit() {
+}
diff --git a/src/runtime/runtime_wasmentry.go b/src/runtime/runtime_wasmentry.go
index 5a135f428..7bb1e1b44 100644
--- a/src/runtime/runtime_wasmentry.go
+++ b/src/runtime/runtime_wasmentry.go
@@ -1,4 +1,4 @@
-//go:build tinygo.wasm && !wasip2 && !js
+//go:build tinygo.wasm && !js
 
 package runtime
 
diff --git a/targets/wasip2.json b/targets/wasip2.json
index b32a68197..4b0e67591 100644
--- a/targets/wasip2.json
+++ b/targets/wasip2.json
@@ -3,6 +3,7 @@
 	"cpu":           "generic",
 	"features":      "+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext",
 	"build-tags":    ["tinygo.wasm", "wasip2"],
+	"buildmode":     "c-shared",
 	"goos":          "linux",
 	"goarch":        "arm",
 	"linker":        "wasm-ld",