Generalize -scheduler=none to support most platforms

src/internal/task/task_stack_cortexm.go

@@ -1,4 +1,4 @@
-// +build scheduler.tasks, cortexm
+// +build scheduler.tasks,cortexm
 
 package task
 

src/runtime/gc_conservative.go

@@ -180,7 +180,7 @@ func (b gcBlock) unmark() {
 // No memory may be allocated before this is called. That means the runtime and
 // any packages the runtime depends upon may not allocate memory during package
 // initialization.
-func init() {
+func initHeap() {
 	totalSize := heapEnd - heapStart
 
 	// Allocate some memory to keep 2 bits of information about every block.

src/runtime/gc_leaking.go

@@ -45,3 +45,7 @@ func KeepAlive(x interface{}) {
 func SetFinalizer(obj interface{}, finalizer interface{}) {
 	// Unimplemented.
 }
+
+func initHeap() {
+	// Nothing to initialize.
+}

src/runtime/gc_none.go

@@ -27,3 +27,7 @@ func KeepAlive(x interface{}) {
 func SetFinalizer(obj interface{}, finalizer interface{}) {
 	// Unimplemented.
 }
+
+func initHeap() {
+	// Nothing to initialize.
+}

src/runtime/runtime_arm7tdmi.go

@@ -30,20 +30,16 @@ var _sidata [0]byte
 //go:extern _edata
 var _edata [0]byte
 
+func postinit() {}
+
 // Entry point for Go. Initialize all packages and call main.main().
 //go:export main
 func main() {
 	// Initialize .data and .bss sections.
 	preinit()
 
-	// Run initializers of all packages.
-	initAll()
-
-	// Compiler-generated call to main.main().
-	go callMain()
-
-	// Run the scheduler.
-	scheduler()
+	// Run program.
+	run()
 }
 
 func preinit() {

src/runtime/runtime_atsamd21.go

@@ -13,12 +13,12 @@ import (
 
 type timeUnit int64
 
+func postinit() {}
+
 //go:export Reset_Handler
 func main() {
 	preinit()
-	initAll()
-	go callMain()
-	scheduler()
+	run()
 	abort()
 }
 

src/runtime/runtime_atsamd51.go

@@ -12,12 +12,12 @@ import (
 
 type timeUnit int64
 
+func postinit() {}
+
 //go:export Reset_Handler
 func main() {
 	preinit()
-	initAll()
-	go callMain()
-	scheduler()
+	run()
 	abort()
 }
 

src/runtime/runtime_avr.go

@@ -39,9 +39,7 @@ var _ebss [0]byte
 //go:export main
 func main() {
 	preinit()
-	initAll()
-	postinit()
-	callMain()
+	run()
 	abort()
 }
 

src/runtime/runtime_cortexm_qemu.go

@@ -17,12 +17,12 @@ const tickMicros = 1
 
 var timestamp timeUnit
 
+func postinit() {}
+
 //go:export Reset_Handler
 func main() {
 	preinit()
-	initAll()
-	go callMain()
-	scheduler()
+	run()
 	arm.SemihostingCall(arm.SemihostingReportException, arm.SemihostingApplicationExit)
 	abort()
 }

src/runtime/runtime_fe310.go

@@ -31,6 +31,8 @@ var _sidata [0]byte
 //go:extern _edata
 var _edata [0]byte
 
+func postinit() {}
+
 //go:export main
 func main() {
 	// Zero the PLIC enable bits on startup: they are not zeroed at reset.
@@ -51,9 +53,7 @@ func main() {
 
 	preinit()
 	initPeripherals()
-	initAll()
-	go callMain()
-	scheduler()
+	run()
 	abort()
 }
 

src/runtime/runtime_nrf.go

@@ -17,13 +17,13 @@ const tickMicros = 1024 * 32
 //go:linkname systemInit SystemInit
 func systemInit()
 
+func postinit() {}
+
 //go:export Reset_Handler
 func main() {
 	systemInit()
 	preinit()
-	initAll()
-	go callMain()
-	scheduler()
+	run()
 	abort()
 }
 

src/runtime/runtime_stm32.go

@@ -4,11 +4,11 @@ package runtime
 
 type timeUnit int64
 
+func postinit() {}
+
 //go:export Reset_Handler
 func main() {
 	preinit()
-	initAll()
-	go callMain()
-	scheduler()
+	run()
 	abort()
 }

src/runtime/runtime_unix.go

@@ -26,10 +26,7 @@ func clock_gettime(clk_id int32, ts *timespec)
 
 const heapSize = 1 * 1024 * 1024 // 1MB to start
 
-var (
-	heapStart = uintptr(malloc(heapSize))
-	heapEnd   = heapStart + heapSize
-)
+var heapStart, heapEnd uintptr
 
 type timeUnit int64
 
@@ -45,17 +42,15 @@ type timespec struct {
 
 const CLOCK_MONOTONIC_RAW = 4
 
+func postinit() {}
+
 // Entry point for Go. Initialize all packages and call main.main().
 //go:export main
 func main() int {
-	// Run initializers of all packages.
-	initAll()
-
-	// Compiler-generated call to main.main().
-	go callMain()
+	heapStart = uintptr(malloc(heapSize))
+	heapEnd = heapStart + heapSize
 
-	// Run scheduler.
-	scheduler()
+	run()
 
 	// For libc compatibility.
 	return 0

src/runtime/runtime_wasm.go

@@ -18,11 +18,15 @@ type wasiIOVec struct {
 //export fd_write
 func fd_write(id uint32, iovs *wasiIOVec, iovs_len uint, nwritten *uint) (errno uint)
 
+func postinit() {}
+
 //export _start
 func _start() {
-	initAll()
-	go callMain()
-	scheduler()
+	// 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()
 }
 
 // Using global variables to avoid heap allocation.

src/runtime/scheduler_any.go

@@ -10,3 +10,15 @@ func sleep(duration int64) {
 	addSleepTask(task.Current(), duration)
 	task.Pause()
 }
+
+// run is called by the program entry point to execute the go program.
+// With a scheduler, init and the main function are invoked in a goroutine before starting the scheduler.
+func run() {
+	initHeap()
+	go func() {
+		initAll()
+		postinit()
+		callMain()
+	}()
+	scheduler()
+}

src/runtime/scheduler_none.go

@@ -12,3 +12,12 @@ func sleep(duration int64) {
 func getSystemStackPointer() uintptr {
 	return getCurrentStackPointer()
 }
+
+// run is called by the program entry point to execute the go program.
+// With the "none" scheduler, init and the main function are invoked directly.
+func run() {
+	initHeap()
+	initAll()
+	postinit()
+	callMain()
+}