llgo/ssa: Alloca, ArrayAlloca

cl/_testcgo/alloca/in.go

@@ -0,0 +1,14 @@
+package main
+
+import (
+	"unsafe"
+
+	"github.com/goplus/llgo/internal/runtime/c"
+)
+
+func main() {
+	s := c.String("Hi\n")
+	s2 := c.Alloca(4)
+	c.Memcpy(s2, unsafe.Pointer(s), 4)
+	c.Printf(c.String("%s"), s)
+}

cl/_testcgo/alloca/out.ll

@@ -0,0 +1,36 @@
+; ModuleID = 'main'
+source_filename = "main"
+
+%"github.com/goplus/llgo/internal/runtime.String" = type { ptr, i64 }
+
+@"main.init$guard" = global ptr null
+
+define void @main.init() {
+_llgo_0:
+  %0 = load i1, ptr @"main.init$guard", align 1
+  br i1 %0, label %_llgo_2, label %_llgo_1
+
+_llgo_1:                                          ; preds = %_llgo_0
+  store i1 true, ptr @"main.init$guard", align 1
+  br label %_llgo_2
+
+_llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
+  ret void
+}
+
+define void @main() {
+_llgo_0:
+  call void @main.init()
+  %0 = call ptr @"github.com/goplus/llgo/internal/runtime/c.String"([4 x i8] c"Hi\0A\00")
+  %1 = alloca i8, i64 4, align 1
+  %2 = call ptr @memcpy(ptr %1, ptr %0, i64 4)
+  %3 = call ptr @"github.com/goplus/llgo/internal/runtime/c.String"([3 x i8] c"%s\00")
+  %4 = call i32 (ptr, ...) @printf(ptr %3, ptr %0)
+  ret void
+}
+
+declare ptr @"github.com/goplus/llgo/internal/runtime/c.String"(%"github.com/goplus/llgo/internal/runtime.String")
+
+declare ptr @memcpy(ptr, ptr, i64)
+
+declare i32 @printf(ptr, ...)

cl/compile.go

@@ -282,6 +282,14 @@ func cstr(b llssa.Builder, args []ssa.Value) (ret llssa.Expr) {
 	panic("cstr(<string-literal>): invalid arguments")
 }
 
+func (p *context) alloca(b llssa.Builder, args []ssa.Value) (ret llssa.Expr) {
+	if len(args) == 1 {
+		n := p.compileValue(b, args[0])
+		return b.Alloca(n)
+	}
+	panic("alloca(size uintptr): invalid arguments")
+}
+
 func (p *context) compileInstrOrValue(b llssa.Builder, iv instrOrValue, asValue bool) (ret llssa.Expr) {
 	if asValue {
 		if v, ok := p.bvals[iv]; ok {
@@ -319,6 +327,8 @@ func (p *context) compileInstrOrValue(b llssa.Builder, iv instrOrValue, asValue
 				ret = b.Call(fn.Expr, args...)
 			case llgoCstr:
 				ret = cstr(b, call.Args)
+			case llgoAlloca:
+				ret = p.alloca(b, call.Args)
 			default:
 				panic("todo")
 			}