From 217e6f3b8ead65497bcc56a0f70349e9fed7ebea Mon Sep 17 00:00:00 2001
From: Delyan Angelov <delian66@gmail.com>
Date: Fri, 10 Apr 2020 22:00:54 +0300
Subject: [PATCH] checker/parser: allow for fixed array with sizes defined with
 a const

---
 vlib/net/socket.v                             |  3 --
 vlib/v/ast/ast.v                              |  2 +
 vlib/v/ast/scope.v                            |  6 ++-
 vlib/v/ast/str.v                              |  3 ++
 vlib/v/checker/checker.v                      | 38 ++++++++++++------
 vlib/v/gen/cgen.v                             |  8 ++--
 vlib/v/parser/parser.v                        | 22 ++++++++---
 .../static_arrays_using_const_for_size_test.v | 39 +++++++++++++++++++
 vlib/v/token/position.v                       |  4 ++
 9 files changed, 99 insertions(+), 26 deletions(-)
 create mode 100644 vlib/v/tests/static_arrays_using_const_for_size_test.v

diff --git a/vlib/net/socket.v b/vlib/net/socket.v
index 6d8cbc76ce..5f5009a9d3 100644
--- a/vlib/net/socket.v
+++ b/vlib/net/socket.v
@@ -302,7 +302,6 @@ pub fn (s Socket) close() ?int {
 pub const (
 	CRLF = '\r\n'
 	MAX_READ = 400
-	xxx = 400
 	MSG_PEEK = 0x02
 )
 // write - write a string with CRLF after it over the socket s
@@ -317,7 +316,6 @@ pub fn (s Socket) write(str string) ?int {
 
 // read_line - retrieves a line from the socket s (i.e. a string ended with \n)
 pub fn (s Socket) read_line() string {
-	//mut buf2 := [xxx]byte // where C.recv will store the network data
 	mut buf := [MAX_READ]byte // where C.recv will store the network data
 	mut res := '' // The final result, including the ending \n.
 	for {
@@ -385,4 +383,3 @@ pub fn (s Socket) get_port() int {
 	C.getsockname(s.sockfd, &addr, &size)
 	return C.ntohs(addr.sin_port)
 }
-
diff --git a/vlib/v/ast/ast.v b/vlib/v/ast/ast.v
index e03080ea8b..0abf933a62 100644
--- a/vlib/v/ast/ast.v
+++ b/vlib/v/ast/ast.v
@@ -588,6 +588,8 @@ pub struct ArrayInit {
 pub:
 	pos       token.Position
 	exprs     []Expr
+	is_fixed  bool
+	mod       string
 mut:
 	elem_type table.Type
 	typ       table.Type
diff --git a/vlib/v/ast/scope.v b/vlib/v/ast/scope.v
index bacac487e6..1aca6c7346 100644
--- a/vlib/v/ast/scope.v
+++ b/vlib/v/ast/scope.v
@@ -56,7 +56,8 @@ pub fn (s &Scope) is_known(name string) bool {
 
 pub fn (s &Scope) find_var(name string) ?Var {
 	if obj := s.find(name) {
-		match obj {
+		v := ScopeObject(obj)
+		match v {
 			Var {
 				return *it
 			}
@@ -68,7 +69,8 @@ pub fn (s &Scope) find_var(name string) ?Var {
 
 pub fn (s &Scope) find_const(name string) ?ConstField {
 	if obj := s.find(name) {
-		match obj {
+		cf := ScopeObject(obj)
+		match cf {
 			ConstField {
 				return *it
 			}
diff --git a/vlib/v/ast/str.v b/vlib/v/ast/str.v
index 766096f3c4..ff25baecac 100644
--- a/vlib/v/ast/str.v
+++ b/vlib/v/ast/str.v
@@ -85,6 +85,9 @@ pub fn (x Expr) str() string {
 		PrefixExpr {
 			return it.op.str() + it.right.str()
 		}
+		CharLiteral {
+			return '`$it.val`'
+		}
 		IntegerLiteral {
 			return it.val
 		}
diff --git a/vlib/v/checker/checker.v b/vlib/v/checker/checker.v
index a4f6ea3e18..8e60b4e7a6 100644
--- a/vlib/v/checker/checker.v
+++ b/vlib/v/checker/checker.v
@@ -706,7 +706,7 @@ pub fn (c mut Checker) array_init(array_init mut ast.ArrayInit) table.Type {
 		idx := c.table.find_or_register_array(elem_type, 1)
 		array_init.typ = table.new_type(idx)
 		array_init.elem_type = elem_type
-	} else if array_init.exprs.len == 1 && array_init.elem_type != table.void_type {
+	} else if array_init.is_fixed && array_init.exprs.len == 1 && array_init.elem_type != table.void_type {
 		// [50]byte
 		mut fixed_size := 1
 		match array_init.exprs[0] {
@@ -714,19 +714,23 @@ pub fn (c mut Checker) array_init(array_init mut ast.ArrayInit) table.Type {
 				fixed_size = it.val.int()
 			}
 			ast.Ident {
-				/*
-				QTODO
-				scope := c.file.scope.innermost(array_init.pos.pos)
-				if obj := c.file.global_scope.find(it.name) {
+				//if obj := c.file.global_scope.find_const(it.name) {
+				//if  obj := scope.find(it.name) {
+				//scope := c.file.scope.innermost(array_init.pos.pos)
+				//eprintln('scope: ${scope.str()}')
+				//scope.find(it.name) or {
+				//	c.error('undefined: `$it.name`', array_init.pos)
+				//}
+				mut full_const_name := if it.mod == 'main' { it.name } else {it.mod + '.' + it.name }
+				if  obj := c.file.global_scope.find_const( full_const_name ) {
+					cf := ast.ConstField(obj)
+					if cint := is_const_integer(cf) {
+						fixed_size = cint.val.int()
+					}
 				} else {
-					c.error(it.name, array_init.pos)
+					c.error('non existant integer const $full_const_name while initializing the size of a static array', array_init.pos)
 				}
-				scope.find(it.name) or {
-					c.error('undefined: `$it.name`', array_init.pos)
-				}
-*/
-			}
-			else {
+			} else {
 				c.error('expecting `int` for fixed size', array_init.pos)
 			}
 		}
@@ -737,6 +741,16 @@ pub fn (c mut Checker) array_init(array_init mut ast.ArrayInit) table.Type {
 	return array_init.typ
 }
 
+fn is_const_integer(cfield ast.ConstField) ?ast.IntegerLiteral {
+	match cfield.expr {
+		ast.IntegerLiteral {
+			return *it
+		}
+		else {}
+	}
+	return none
+}
+
 fn (c mut Checker) stmt(node ast.Stmt) {
 	// c.expected_type = table.void_type
 	match mut node {
diff --git a/vlib/v/gen/cgen.v b/vlib/v/gen/cgen.v
index df4c948b23..ebc7550020 100644
--- a/vlib/v/gen/cgen.v
+++ b/vlib/v/gen/cgen.v
@@ -723,7 +723,7 @@ fn (g mut Gen) gen_assign_stmt(assign_stmt ast.AssignStmt) {
 				mut is_fixed_array_init := false
 				match val {
 					ast.ArrayInit {
-						is_fixed_array_init = right_sym.kind == .array_fixed
+						is_fixed_array_init = it.is_fixed
 					}
 					else {}
 				}
@@ -740,15 +740,15 @@ fn (g mut Gen) gen_assign_stmt(assign_stmt ast.AssignStmt) {
 						return
 					}
 				}
-				if !is_fixed_array_init {
+				if is_fixed_array_init {
+					g.write('= {0}')
+				} else {
 					g.write(' = ')
 					if !is_decl {
 						g.expr_with_cast(val, assign_stmt.left_types[i], ident_var_info.typ)
 					} else {
 						g.expr(val)
 					}
-				} else if is_fixed_array_init {
-					g.write('= {0}')
 				}
 				if gen_or {
 					g.or_block(ident.name, or_stmts, return_type)
diff --git a/vlib/v/parser/parser.v b/vlib/v/parser/parser.v
index 3921478cc6..3dd56d2b34 100644
--- a/vlib/v/parser/parser.v
+++ b/vlib/v/parser/parser.v
@@ -513,19 +513,28 @@ fn (p mut Parser) range_expr(low ast.Expr) ast.Expr {
 	return node
 }
 */
+
 pub fn (p &Parser) error(s string) {
+	p.error_with_pos(s, p.tok.position())
+}
+
+pub fn (p &Parser) warn(s string) {
+	p.warn_with_pos(s, p.tok.position())
+}
+
+pub fn (p &Parser) error_with_pos(s string, pos token.Position) {
 	mut kind := 'error:'
 	if p.pref.is_verbose {
 		print_backtrace()
 		kind = 'parser error:'
 	}
-	ferror := util.formatted_error(kind, s, p.file_name, p.tok.position())
+	ferror := util.formatted_error(kind, s, p.file_name, pos)
 	eprintln(ferror)
 	exit(1)
 }
 
-pub fn (p &Parser) warn(s string) {
-	ferror := util.formatted_error('warning:', s, p.file_name, p.tok.position())
+pub fn (p &Parser) warn_with_pos(s string, pos token.Position) {
+	ferror := util.formatted_error('warning:', s, p.file_name, pos)
 	eprintln(ferror)
 }
 
@@ -1298,6 +1307,7 @@ fn (p mut Parser) array_init() ast.ArrayInit {
 	mut array_type := table.void_type
 	mut elem_type := table.void_type
 	mut exprs := []ast.Expr
+	is_fixed := false
 	if p.tok.kind == .rsbr {
 		// []typ => `[]` and `typ` must be on the same line
 		line_nr := p.tok.line_nr
@@ -1311,7 +1321,7 @@ fn (p mut Parser) array_init() ast.ArrayInit {
 			array_type = table.new_type(idx)
 		}
 	} else {
-		// [1,2,3]
+		// [1,2,3] or [const]byte
 		for i := 0; p.tok.kind != .rsbr; i++ {
 			expr := p.expr(0)
 			exprs << expr
@@ -1325,7 +1335,7 @@ fn (p mut Parser) array_init() ast.ArrayInit {
 		// [100]byte
 		if exprs.len == 1 && p.tok.kind in [.name, .amp] && p.tok.line_nr == line_nr {
 			elem_type = p.parse_type()
-			// p.warn('fixed size array')
+			is_fixed = true
 		}
 	}
 	// !
@@ -1343,6 +1353,8 @@ fn (p mut Parser) array_init() ast.ArrayInit {
 		len: len
 	}
 	return ast.ArrayInit{
+		is_fixed: is_fixed
+		mod: p.mod
 		elem_type: elem_type
 		typ: array_type
 		exprs: exprs
diff --git a/vlib/v/tests/static_arrays_using_const_for_size_test.v b/vlib/v/tests/static_arrays_using_const_for_size_test.v
new file mode 100644
index 0000000000..3a938047eb
--- /dev/null
+++ b/vlib/v/tests/static_arrays_using_const_for_size_test.v
@@ -0,0 +1,39 @@
+const (
+	sbuffer_size = 10
+)
+
+fn test_hardcoded_static_arr(){
+	myints := [10]int
+	size := sizeof( myints )
+	assert size == 40
+}
+
+fn test_const_based_static_arr(){
+	myints := [sbuffer_size]int
+	size := sizeof( myints )
+	assert size == 40
+}
+
+fn test_const_based_static_arr_of_f64(){
+	myf64 := [sbuffer_size]f64
+	size := sizeof( myf64 )
+	assert size == 80
+}
+
+fn test_const_based_static_arr_of_f32(){
+	myf32 := [sbuffer_size]f32
+	size := sizeof( myf32 )
+	assert size == 40
+}
+
+fn test_const_based_static_arr_of_i8(){
+	myi8 := [sbuffer_size]i8
+	size := sizeof( myi8 )
+	assert size == 10
+}
+
+fn test_const_based_static_arr_of_i16(){
+	myi16 := [sbuffer_size]i16
+	size := sizeof( myi16 )
+	assert size == 20
+}
diff --git a/vlib/v/token/position.v b/vlib/v/token/position.v
index 5747183666..ecc0272c6e 100644
--- a/vlib/v/token/position.v
+++ b/vlib/v/token/position.v
@@ -10,6 +10,10 @@ pub:
 	len     int // length of the literal in the source
 }
 
+pub fn (pos Position) str() string {
+	return 'Position{ line_nr: $pos.line_nr, pos: $pos.pos, len: $pos.len }'
+}
+
 [inline]
 pub fn (tok &Token) position() Position {
 	return Position{