From 79b4b0e6c87c3caf9871322e9a9bedd5c2bba701 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Uwe=20Kr=C3=BCger?=
 <45282134+UweKrueger@users.noreply.github.com>
Date: Sun, 24 Jan 2021 00:06:43 +0100
Subject: [PATCH] parser: assure explicit `map` init contains no parameters
 (#8299)

---
 vlib/v/parser/parse_type.v             | 4 ++++
 vlib/v/parser/parser.v                 | 8 ++++++--
 vlib/v/parser/tests/map_init.out       | 6 ++++++
 vlib/v/parser/tests/map_init.vv        | 4 ++++
 vlib/v/parser/tests/map_init_void.out  | 5 +++++
 vlib/v/parser/tests/map_init_void.vv   | 3 +++
 vlib/v/parser/tests/map_init_void2.out | 5 +++++
 vlib/v/parser/tests/map_init_void2.vv  | 7 +++++++
 8 files changed, 40 insertions(+), 2 deletions(-)
 create mode 100644 vlib/v/parser/tests/map_init.out
 create mode 100644 vlib/v/parser/tests/map_init.vv
 create mode 100644 vlib/v/parser/tests/map_init_void.out
 create mode 100644 vlib/v/parser/tests/map_init_void.vv
 create mode 100644 vlib/v/parser/tests/map_init_void2.out
 create mode 100644 vlib/v/parser/tests/map_init_void2.vv

diff --git a/vlib/v/parser/parse_type.v b/vlib/v/parser/parse_type.v
index 59b045f866..fd2338f782 100644
--- a/vlib/v/parser/parse_type.v
+++ b/vlib/v/parser/parse_type.v
@@ -90,6 +90,10 @@ pub fn (mut p Parser) parse_map_type() table.Type {
 		// error is reported in parse_type
 		return 0
 	}
+	if value_type.idx() == table.void_type_idx {
+		p.error_with_pos('map value type cannot be void', p.tok.position())
+		return 0
+	}
 	idx := p.table.find_or_register_map(key_type, value_type)
 	return table.new_type(idx)
 }
diff --git a/vlib/v/parser/parser.v b/vlib/v/parser/parser.v
index a8c93cd484..e8cbcfe2c0 100644
--- a/vlib/v/parser/parser.v
+++ b/vlib/v/parser/parser.v
@@ -1140,9 +1140,13 @@ pub fn (mut p Parser) name_expr() ast.Expr {
 	// `map[string]int` initialization
 	if p.tok.lit == 'map' && p.peek_tok.kind == .lsbr {
 		map_type := p.parse_map_type()
-		if p.tok.kind == .lcbr && p.peek_tok.kind == .rcbr {
-			p.next()
+		if p.tok.kind == .lcbr {
 			p.next()
+			if p.tok.kind == .rcbr {
+				p.next()
+			} else {
+				p.error('`}` expected; explicit `map` initialization does not support parameters')
+			}
 		}
 		return ast.MapInit{
 			typ: map_type
diff --git a/vlib/v/parser/tests/map_init.out b/vlib/v/parser/tests/map_init.out
new file mode 100644
index 0000000000..71852660c1
--- /dev/null
+++ b/vlib/v/parser/tests/map_init.out
@@ -0,0 +1,6 @@
+vlib/v/parser/tests/map_init.vv:3:22: error: `}` expected; explicit `map` initialization does not support parameters
+    1 | fn main() {
+    2 |     a := map[string]int{}
+    3 |     b := map[string]f64{cap: 10}
+      |                         ~~~
+    4 | }
diff --git a/vlib/v/parser/tests/map_init.vv b/vlib/v/parser/tests/map_init.vv
new file mode 100644
index 0000000000..2ab972d113
--- /dev/null
+++ b/vlib/v/parser/tests/map_init.vv
@@ -0,0 +1,4 @@
+fn main() {
+	a := map[string]int{}
+	b := map[string]f64{cap: 10}
+}
diff --git a/vlib/v/parser/tests/map_init_void.out b/vlib/v/parser/tests/map_init_void.out
new file mode 100644
index 0000000000..fd76d7ee0f
--- /dev/null
+++ b/vlib/v/parser/tests/map_init_void.out
@@ -0,0 +1,5 @@
+vlib/v/parser/tests/map_init_void.vv:2:18: error: map value type cannot be void
+    1 | fn main() {
+    2 |     m := map[string]{}
+      |                     ^
+    3 | }
diff --git a/vlib/v/parser/tests/map_init_void.vv b/vlib/v/parser/tests/map_init_void.vv
new file mode 100644
index 0000000000..5ad2727fb2
--- /dev/null
+++ b/vlib/v/parser/tests/map_init_void.vv
@@ -0,0 +1,3 @@
+fn main() {
+	m := map[string]{}
+}
diff --git a/vlib/v/parser/tests/map_init_void2.out b/vlib/v/parser/tests/map_init_void2.out
new file mode 100644
index 0000000000..81031dc5e5
--- /dev/null
+++ b/vlib/v/parser/tests/map_init_void2.out
@@ -0,0 +1,5 @@
+vlib/v/parser/tests/map_init_void2.vv:1:19: error: expecting type declaration
+    1 | fn f(m map[string]) {
+      |                   ^
+    2 |     println('illegal function')
+    3 | }
diff --git a/vlib/v/parser/tests/map_init_void2.vv b/vlib/v/parser/tests/map_init_void2.vv
new file mode 100644
index 0000000000..0b9a8e43a0
--- /dev/null
+++ b/vlib/v/parser/tests/map_init_void2.vv
@@ -0,0 +1,7 @@
+fn f(m map[string]) {
+	println('illegal function')
+}
+
+fn main() {
+	println('Hello world')
+}