feat: implement llgo.stackSave

cl/_testrt/stacksave/in.go

@@ -0,0 +1,14 @@
+package main
+
+import (
+	"unsafe"
+	_ "unsafe"
+)
+
+//go:linkname getsp llgo.stackSave
+func getsp() unsafe.Pointer
+
+func main() {
+	sp := getsp()
+	println(sp)
+}

cl/_testrt/stacksave/out.ll

@@ -0,0 +1,34 @@
+; ModuleID = 'github.com/goplus/llgo/cl/_testrt/stacksave'
+source_filename = "github.com/goplus/llgo/cl/_testrt/stacksave"
+
+@"github.com/goplus/llgo/cl/_testrt/stacksave.init$guard" = global i1 false, align 1
+
+define void @"github.com/goplus/llgo/cl/_testrt/stacksave.init"() {
+_llgo_0:
+  %0 = load i1, ptr @"github.com/goplus/llgo/cl/_testrt/stacksave.init$guard", align 1
+  br i1 %0, label %_llgo_2, label %_llgo_1
+
+_llgo_1:                                          ; preds = %_llgo_0
+  store i1 true, ptr @"github.com/goplus/llgo/cl/_testrt/stacksave.init$guard", align 1
+  br label %_llgo_2
+
+_llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
+  ret void
+}
+
+define void @"github.com/goplus/llgo/cl/_testrt/stacksave.main"() {
+_llgo_0:
+  %0 = call ptr @llvm.stacksave()
+  call void @"github.com/goplus/llgo/runtime/internal/runtime.PrintPointer"(ptr %0)
+  call void @"github.com/goplus/llgo/runtime/internal/runtime.PrintByte"(i8 10)
+  ret void
+}
+
+; Function Attrs: nocallback nofree nosync nounwind willreturn
+declare ptr @llvm.stacksave() #0
+
+declare void @"github.com/goplus/llgo/runtime/internal/runtime.PrintPointer"(ptr)
+
+declare void @"github.com/goplus/llgo/runtime/internal/runtime.PrintByte"(i8)
+
+attributes #0 = { nocallback nofree nosync nounwind willreturn }

cl/import.go

@@ -503,7 +503,8 @@ const (
 	llgoCgoCheckPointer = llgoCgoBase + 0x6
 	llgoCgoCgocall      = llgoCgoBase + 0x7
 
-	llgoAsm = llgoInstrBase + 0x40
+	llgoAsm       = llgoInstrBase + 0x40
+	llgoStackSave = llgoInstrBase + 0x41
 
 	llgoAtomicOpLast = llgoAtomicOpBase + int(llssa.OpUMin)
 )

cl/instr.go

@@ -425,7 +425,8 @@ var llgoInstrs = map[string]int{
 	"_cgoCheckPointer":     llgoCgoCheckPointer,
 	"_cgo_runtime_cgocall": llgoCgoCgocall,
 
-	"asm": llgoAsm,
+	"asm":       llgoAsm,
+	"stackSave": llgoStackSave,
 }
 
 // funcOf returns a function by name and set ftype = goFunc, cFunc, etc.
@@ -601,6 +602,8 @@ func (p *context) call(b llssa.Builder, act llssa.DoAction, call *ssa.CallCommon
 			ret = p.sigsetjmp(b, args)
 		case llgoSiglongjmp:
 			p.siglongjmp(b, args)
+		case llgoStackSave:
+			ret = b.StackSave()
 		case llgoSigjmpbuf: // func sigjmpbuf()
 			ret = b.AllocaSigjmpBuf()
 		case llgoDeferData: // func deferData() *Defer