From 8a8f50a6a0efd85814bd5bc90ef08631fcf52579 Mon Sep 17 00:00:00 2001
From: Alexander Medvednikov <alexander@medvednikov.com>
Date: Sun, 15 Mar 2020 08:18:42 +0100
Subject: [PATCH] cgen: unwrapped optionals

---
 vlib/v/checker/checker.v | 6 +++++-
 vlib/v/gen/cgen.v        | 6 +++++-
 vlib/v/gen/tests/3.c     | 9 ++++++++-
 vlib/v/gen/tests/3.vv    | 8 ++++++++
 vlib/v/table/atypes.v    | 5 +++++
 5 files changed, 31 insertions(+), 3 deletions(-)

diff --git a/vlib/v/checker/checker.v b/vlib/v/checker/checker.v
index 95c75b47e3..9238ad876f 100644
--- a/vlib/v/checker/checker.v
+++ b/vlib/v/checker/checker.v
@@ -727,10 +727,14 @@ pub fn (c mut Checker) ident(ident mut ast.Ident) table.Type {
 				typ: typ
 				is_optional: table.type_is_optional(typ)
 			}
+			// unwrap optional (`println(x)`)
+			if table.type_is_optional(typ) {
+				return table.type_clear_extra(typ)
+			}
 			return typ
 		}
 	}
-	// second use, already resovled in unresovled branch
+	// second use, already resovled in unresolved branch
 	else if ident.kind == .constant {
 		info := ident.info as ast.IdentVar
 		return info.typ
diff --git a/vlib/v/gen/cgen.v b/vlib/v/gen/cgen.v
index e77b22c892..d96a70940e 100644
--- a/vlib/v/gen/cgen.v
+++ b/vlib/v/gen/cgen.v
@@ -21,6 +21,7 @@ mut:
 	is_assign_expr bool // inside left part of assign expr (for array_set(), etc)
 	is_array_set   bool
 	is_amp         bool // for `&Foo{}` to merge PrefixExpr `&` and StructInit `Foo{}`; also for `&byte(0)` etc
+	optionals      []string // to avoid duplicates TODO perf, use map
 }
 
 pub fn cgen(files []ast.File, table &table.Table) string {
@@ -69,7 +70,10 @@ pub fn (g mut Gen) typ(t table.Type) string {
 	}
 	if table.type_is_optional(t) {
 		styp = 'Option_' + styp
-		g.definitions.writeln('typedef Option $styp;')
+		if !(styp in g.optionals) {
+			g.definitions.writeln('typedef Option $styp;')
+			g.optionals << styp
+		}
 	}
 	return styp
 }
diff --git a/vlib/v/gen/tests/3.c b/vlib/v/gen/tests/3.c
index 17c7cbf5f5..abf97d5623 100644
--- a/vlib/v/gen/tests/3.c
+++ b/vlib/v/gen/tests/3.c
@@ -5,9 +5,14 @@ struct User {
 
 // multi return structs
 // end of definitions #endif
-
+typedef Option Option_int;
+Option_int get_opt();
 void User_foo(User* u);
 
+Option_int get_opt() {
+	return opt_ok(& (int []) { 0 }, sizeof(int));
+}
+
 void User_foo(User* u) {
 	int age = u->age;
 	array_string zzz = array_repeat(new_array_from_c_array(1, 1, sizeof(string), (string[]){
@@ -21,5 +26,7 @@ int main() {
 	user.age = 10;
 	user.age++;
 	user.name = tos3("bob");
+	Option_int n = get_opt();
+	int a = /*opt*/(*(int*)n.data) + 3;
 	return 0;
 }
diff --git a/vlib/v/gen/tests/3.vv b/vlib/v/gen/tests/3.vv
index b6240e48da..4ad37cfa19 100644
--- a/vlib/v/gen/tests/3.vv
+++ b/vlib/v/gen/tests/3.vv
@@ -3,6 +3,10 @@ struct User {
 	name string
 }
 
+fn get_opt() ?int {
+	return 0
+}
+
 fn (u &User) foo() {
 	age := u.age
 	zzz := [''].repeat(u.age)
@@ -13,4 +17,8 @@ fn main() {
 	user.age = 10
 	user.age++
 	user.name = 'bob'
+	n := get_opt() or {
+		return
+	}
+	a := n + 3
 }
diff --git a/vlib/v/table/atypes.v b/vlib/v/table/atypes.v
index a52f526b1f..6005721d40 100644
--- a/vlib/v/table/atypes.v
+++ b/vlib/v/table/atypes.v
@@ -81,6 +81,11 @@ pub fn type_deref(t Type) Type {
 	return (int(type_extra(t))<<24) | ((nr_muls - 1)<<16) | u16(type_idx(t))
 }
 
+[inline]
+pub fn type_clear_extra(t Type) Type {
+	return type_set_extra(t, .unset)
+}
+
 // return extra info
 [inline]
 pub fn type_extra(t Type) TypeExtra {