From 051cc732bb5352f9710dc72e0a646acecd340b0d Mon Sep 17 00:00:00 2001
From: Enzo Baldisserri <enzo.baldisserri@outlook.fr>
Date: Thu, 16 Apr 2020 21:04:27 +0200
Subject: [PATCH] cgen: generate typeof for functions

---
 cmd/tools/vtest-fixed.v                 |  1 -
 vlib/v/gen/cgen.v                       | 19 +++++++++++++++++--
 vlib/v/table/table.v                    |  7 +++++++
 vlib/v/tests/typeof_simple_types_test.v |  4 ++++
 vlib/v/tests/typeof_test.v              | 11 ++++++++---
 5 files changed, 36 insertions(+), 6 deletions(-)

diff --git a/cmd/tools/vtest-fixed.v b/cmd/tools/vtest-fixed.v
index 6547340872..29c11101b6 100644
--- a/cmd/tools/vtest-fixed.v
+++ b/cmd/tools/vtest-fixed.v
@@ -32,7 +32,6 @@ const (
 		'vlib/v/tests/string_interpolation_struct_test.v',
 		'vlib/v/tests/string_interpolation_variadic_test.v',
 		'vlib/v/tests/type_test.v',
-		'vlib/v/tests/typeof_test.v',
 		'vlib/v/tests/valgrind/valgrind_test.v', // ubuntu-musl only
 		'vlib/v/tests/pointers_str_test.v',
 		'vlib/net/http/cookie_test.v',
diff --git a/vlib/v/gen/cgen.v b/vlib/v/gen/cgen.v
index cff9fb987a..9940443718 100644
--- a/vlib/v/gen/cgen.v
+++ b/vlib/v/gen/cgen.v
@@ -1103,8 +1103,23 @@ fn (var g Gen) typeof_expr(node ast.TypeOf) {
 		g.write(').typ ))')
 	} else if sym.kind == .array_fixed {
 		fixed_info := sym.info as table.ArrayFixed
-		elem_sym := g.table.get_type_symbol(fixed_info.elem_type)
-		g.write('tos3("[$fixed_info.size]${elem_sym.name}")')
+		typ_name := g.table.get_type_name(fixed_info.elem_type)
+		g.write('tos3("[$fixed_info.size]${typ_name}")')
+	} else if sym.kind == .function {
+		info := sym.info as table.FnType
+		fn_info := info.func
+		mut repr := 'fn ('
+		for i, arg in fn_info.args {
+			if i > 0 {
+				repr += ', '
+			}
+			repr += g.table.get_type_name(arg.typ)
+		}
+		repr += ')'
+		if fn_info.return_type != table.void_type {
+			repr += ' ${g.table.get_type_name(fn_info.return_type)}'
+		}
+		g.write('tos3("$repr")')
 	} else {
 		g.write('tos3("${sym.name}")')
 	}
diff --git a/vlib/v/table/table.v b/vlib/v/table/table.v
index 3d3d69beca..a04e4b084b 100644
--- a/vlib/v/table/table.v
+++ b/vlib/v/table/table.v
@@ -204,6 +204,13 @@ pub fn (t &Table) get_type_symbol(typ Type) &TypeSymbol {
 	panic('get_type_symbol: invalid type (typ=$typ idx=${idx}). This should never happen')
 }
 
+[inline]
+pub fn (t &Table) get_type_name(typ Type) string {
+	typ_sym := t.get_type_symbol(typ)
+	return typ_sym.name
+}
+
+
 // this will override or register builtin type
 // allows prexisitng types added in register_builtins
 // to be overriden with their real type info
diff --git a/vlib/v/tests/typeof_simple_types_test.v b/vlib/v/tests/typeof_simple_types_test.v
index e1f2a8701d..8b06d8390b 100644
--- a/vlib/v/tests/typeof_simple_types_test.v
+++ b/vlib/v/tests/typeof_simple_types_test.v
@@ -17,8 +17,12 @@ type AnotherSumType = XxYyZz | int
 type SuperSumType = MySumType | AnotherSumType | string
 
 fn test_typeof_for_builtin_int_types() {
+	assert typeof(i8(1)) == 'i8'
+	assert typeof(i16(1)) == 'i16'
 	assert typeof(1) == 'int'
 	assert typeof(i64(1)) == 'i64'
+	assert typeof(byte(1)) == 'byte'
+	assert typeof(u16(1)) == 'u16'
 	assert typeof(u32(1)) == 'u32'
 	assert typeof(u64(1)) == 'u64'
 }
diff --git a/vlib/v/tests/typeof_test.v b/vlib/v/tests/typeof_test.v
index 796e02f9aa..f1d7563f78 100644
--- a/vlib/v/tests/typeof_test.v
+++ b/vlib/v/tests/typeof_test.v
@@ -73,15 +73,20 @@ fn test_typeof_on_sumtypes_of_structs() {
 	assert typeof(d) == 'UnaryExpr'
 }
 
-type MyFn fn(int) int
-type MyFn2 fn()
-
 fn myfn(i int) int {
 	return i
 }
 fn myfn2() {}
+fn myfn3(i int, s string) byte {
+	return byte(0)
+}
+fn myfn4() i8 {
+	return -1
+}
 
 fn test_typeof_on_fn() {
 	assert typeof(myfn) == 'fn (int) int'
 	assert typeof(myfn2) == 'fn ()'
+	assert typeof(myfn3) == 'fn (int, string) byte'
+	assert typeof(myfn4) == 'fn () i8'
 }