Merge pull request #57 from xushiwei/q

cl: fake libc

cl/_testcgo/hello/in.go

@@ -0,0 +1,10 @@
+package main
+
+import "github.com/goplus/llgo/cl/internal/libc"
+
+var format = [...]int8{'H', 'e', 'l', 'l', 'o', ' ', '%', 'd', '\n', 0}
+
+func main() {
+	sfmt := &format[0]
+	libc.Printf(sfmt, libc.Strlen(sfmt))
+}

cl/_testcgo/hello/out.ll

@@ -0,0 +1,43 @@
+; ModuleID = 'main'
+source_filename = "main"
+
+@main.format = global ptr null
+@"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
+  call void @"github.com/goplus/llgo/cl/internal/libc.init"()
+  store i8 72, ptr @main.format, align 1
+  store i8 101, ptr getelementptr inbounds (i8, ptr @main.format, i64 1), align 1
+  store i8 108, ptr getelementptr inbounds (i8, ptr @main.format, i64 2), align 1
+  store i8 108, ptr getelementptr inbounds (i8, ptr @main.format, i64 3), align 1
+  store i8 111, ptr getelementptr inbounds (i8, ptr @main.format, i64 4), align 1
+  store i8 32, ptr getelementptr inbounds (i8, ptr @main.format, i64 5), align 1
+  store i8 37, ptr getelementptr inbounds (i8, ptr @main.format, i64 6), align 1
+  store i8 100, ptr getelementptr inbounds (i8, ptr @main.format, i64 7), align 1
+  store i8 10, ptr getelementptr inbounds (i8, ptr @main.format, i64 8), align 1
+  store i8 0, ptr getelementptr inbounds (i8, ptr @main.format, i64 9), 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 i32 @strlen(ptr @main.format)
+  call void (ptr, ...) @"github.com/goplus/llgo/cl/internal/libc.Printf"(ptr @main.format, i32 %0)
+  ret void
+}
+
+declare void @"github.com/goplus/llgo/cl/internal/libc.init"()
+
+declare i32 @strlen(ptr)
+
+declare void @"github.com/goplus/llgo/cl/internal/libc.Printf"(ptr, ...)

cl/internal/libc/libc.go

@@ -0,0 +1,14 @@
+package libc
+
+import "C"
+import _ "unsafe"
+
+const (
+	LLGoPackage = true
+)
+
+//go:linkname Printf printf
+func Printf(format *int8, __llgo_va_list ...any)
+
+//go:linkname Strlen strlen
+func Strlen(str *int8) C.int