From 4dcef185606e94de5b7af571af7ad21834d5a8d8 Mon Sep 17 00:00:00 2001
From: leongross <leon.gross@9elements.com>
Date: Fri, 28 Jun 2024 10:32:28 +0200
Subject: [PATCH] add signal stubs in runtime

Signed-off-by: leongross <leon.gross@9elements.com>
---
 GNUmakefile                        |  1 +
 src/os/exec.go                     |  4 +++
 src/os/signal/signal_linux.go      | 54 ++++++++++++++++++++++++++++++
 src/os/signal/signal_linux_test.go | 30 +++++++++++++++++
 src/runtime/sigqueue.go            | 26 ++++++++++++++
 5 files changed, 115 insertions(+)
 create mode 100644 src/os/signal/signal_linux.go
 create mode 100644 src/os/signal/signal_linux_test.go
 create mode 100644 src/runtime/sigqueue.go

diff --git a/GNUmakefile b/GNUmakefile
index f06f28a18c..d3982e8976 100644
--- a/GNUmakefile
+++ b/GNUmakefile
@@ -338,6 +338,7 @@ TEST_PACKAGES_FAST = \
 	net/http/internal/ascii \
 	net/mail \
 	os \
+	os/signal \
 	path \
 	reflect \
 	sync \
diff --git a/src/os/exec.go b/src/os/exec.go
index cf295e6fb7..fada70f479 100644
--- a/src/os/exec.go
+++ b/src/os/exec.go
@@ -47,6 +47,10 @@ func (p *ProcessState) Sys() interface{} {
 	return nil // TODO
 }
 
+func (p *ProcessState) Exited() bool {
+	return false // TODO
+}
+
 // ExitCode returns the exit code of the exited process, or -1
 // if the process hasn't exited or was terminated by a signal.
 func (p *ProcessState) ExitCode() int {
diff --git a/src/os/signal/signal_linux.go b/src/os/signal/signal_linux.go
new file mode 100644
index 0000000000..391fb5c7d9
--- /dev/null
+++ b/src/os/signal/signal_linux.go
@@ -0,0 +1,54 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build !plan9 && !windows && !js && !wasm && !wasip1 && !wasip2
+// +build !plan9,!windows,!js,!wasm,!wasip1,!wasip2
+
+package signal
+
+import (
+	"os"
+	"syscall"
+)
+
+const (
+	numSig = 65 // max across all systems
+)
+
+type Signal interface {
+	String() string
+	Signal() // to distinguish from other Stringers
+}
+
+// Defined by the runtime package and used by syscall/sigqueue.go.
+func signal_disable(uint32)
+func signal_enable(uint32)
+func signal_ignore(uint32)
+func signal_ignored(uint32) bool
+func signal_recv() uint32
+
+func signum(sig os.Signal) int {
+	switch sig := sig.(type) {
+	case syscall.Signal:
+		i := int(sig)
+		if i < 0 || i >= numSig {
+			return -1
+		}
+		return i
+	default:
+		return -1
+	}
+}
+
+func enableSignal(sig int) {
+	signal_enable(uint32(sig))
+}
+
+func disableSignal(sig int) {
+	signal_disable(uint32(sig))
+}
+
+func ignoreSignal(sig int) {
+	signal_ignore(uint32(sig))
+}
diff --git a/src/os/signal/signal_linux_test.go b/src/os/signal/signal_linux_test.go
new file mode 100644
index 0000000000..9c58cafd35
--- /dev/null
+++ b/src/os/signal/signal_linux_test.go
@@ -0,0 +1,30 @@
+//go:build !plan9 && !windows && !js && !wasm && !wasip1 && !wasip2
+// +build !plan9,!windows,!js,!wasm,!wasip1,!wasip2
+
+package signal
+
+import (
+	"runtime"
+	"testing"
+)
+
+// The file sigqueue.go contains preliminary stubs for signal handling.
+// Since tinygo ultimately lacks support for signals, these stubs are
+// placeholders for future work.
+// There might be userland applications that rely on these functions
+// from the upstream go package os/signal that we want to enable
+// building and linking.
+
+func TestSignalHandling(t *testing.T) {
+	if runtime.GOOS == "wasip1" || runtime.GOOS == "wasip2" {
+		t.Skip()
+	}
+
+	// This test is a placeholder for future work.
+	// It is here to ensure that the stubs in sigqueue.go
+	// are correctly linked and can be called from userland
+	// applications.
+	enableSignal(0)
+	disableSignal(0)
+	ignoreSignal(0)
+}
diff --git a/src/runtime/sigqueue.go b/src/runtime/sigqueue.go
new file mode 100644
index 0000000000..ff789a605f
--- /dev/null
+++ b/src/runtime/sigqueue.go
@@ -0,0 +1,26 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build !plan9
+// +build !plan9
+
+package runtime
+
+// Stub definitions copied from upstream golang
+// TODO: implement a minimal functional version of these functions
+
+// go: linkname os/signal.signal_disable signal_disable
+func signal_disable(_ uint32) {}
+
+// go: linkname os/signal.signal_enable signal_enable
+func signal_enable(_ uint32) {}
+
+// go: linkname os/signal.signal_ignore signal_ignore
+func signal_ignore(_ uint32) {}
+
+// go: linkname os/signal.signal_ignored signal_ignored
+func signal_ignored(_ uint32) bool { return true }
+
+// go: linkname os/signal.signal_recv signal_recv
+func signal_recv() uint32 { return 0 }