From fd479a2bcdeee6083e38ffb0238b5a6417c582d6 Mon Sep 17 00:00:00 2001
From: "Eliyaan (Nopana)" <103932369+Eliyaan@users.noreply.github.com>
Date: Thu, 11 Sep 2025 15:12:28 +0200
Subject: [PATCH 1/5] native: support more assign ops, reduce code duplication
 (#25283)

---
 vlib/v/gen/native/amd64.v         | 262 +++++++++++++-----------------
 vlib/v/gen/native/tests/assign.vv |  82 ++++++++++
 2 files changed, 191 insertions(+), 153 deletions(-)

diff --git a/vlib/v/gen/native/amd64.v b/vlib/v/gen/native/amd64.v
index 43606579b3..0370e80ea8 100644
--- a/vlib/v/gen/native/amd64.v
+++ b/vlib/v/gen/native/amd64.v
@@ -1753,10 +1753,8 @@ fn (mut c Amd64) mov(r Register, val i32) {
 	}
 }
 
-fn (mut c Amd64) mul_reg(a Amd64Register, b Amd64Register) {
-	if a != .rax {
-		c.g.n_error('mul always operates on rax')
-	}
+// rax times b
+fn (mut c Amd64) mul_reg_rax(b Amd64Register) {
 	match b {
 		.rax {
 			c.g.write8(0x48)
@@ -1799,10 +1797,8 @@ fn (mut c Amd64) imul_reg(r Amd64Register) {
 	}
 }
 
-fn (mut c Amd64) div_reg(a Amd64Register, b Amd64Register) {
-	if a != .rax {
-		c.g.n_error('div always operates on rax')
-	}
+// rax divided by b
+fn (mut c Amd64) div_reg_rax(b Amd64Register) {
 	match b {
 		.rax {
 			c.g.write8(0x48)
@@ -1831,8 +1827,9 @@ fn (mut c Amd64) div_reg(a Amd64Register, b Amd64Register) {
 	c.g.println('div ${b}')
 }
 
-fn (mut c Amd64) mod_reg(a Amd64Register, b Amd64Register) {
-	c.div_reg(a, b)
+// rax % b
+fn (mut c Amd64) mod_reg_rax(b Amd64Register) {
+	c.div_reg_rax(b)
 	c.mov_reg(Amd64Register.rdx, Amd64Register.rax)
 }
 
@@ -2287,36 +2284,6 @@ fn (mut c Amd64) assign_var(var IdentVar, raw_type ast.Type) {
 // TODO: may have a problem if the literal is bigger than max_i64: needs u64
 fn (mut c Amd64) assign_ident_int_lit(node ast.AssignStmt, i i32, int_lit ast.IntegerLiteral, left ast.Ident) {
 	match node.op {
-		.plus_assign {
-			c.mov_var_to_reg(Amd64Register.rax, left)
-			c.mov64(Amd64Register.rdx, i64(int_lit.val.int()))
-			c.add_reg(Amd64Register.rax, Amd64Register.rdx)
-			c.mov_reg_to_var(left, Amd64Register.rax)
-		}
-		.minus_assign {
-			c.mov_var_to_reg(Amd64Register.rax, left)
-			c.mov64(Amd64Register.rdx, i64(int_lit.val.int()))
-			c.sub_reg(Amd64Register.rax, Amd64Register.rdx)
-			c.mov_reg_to_var(left, Amd64Register.rax)
-		}
-		.mult_assign {
-			c.mov_var_to_reg(Amd64Register.rax, left)
-			c.mov64(Amd64Register.rdx, i64(int_lit.val.int()))
-			c.mul_reg(.rax, .rdx)
-			c.mov_reg_to_var(left, Amd64Register.rax)
-		}
-		.div_assign {
-			c.mov_var_to_reg(Amd64Register.rax, left)
-			c.mov64(Amd64Register.rdx, i64(int_lit.val.int()))
-			c.div_reg(.rax, .rdx)
-			c.mov_reg_to_var(left, Amd64Register.rax)
-		}
-		.mod_assign {
-			c.mov_var_to_reg(Amd64Register.rax, left)
-			c.mov64(Amd64Register.rdx, i64(int_lit.val.int()))
-			c.mod_reg(.rax, .rdx)
-			c.mov_reg_to_var(left, Amd64Register.rax)
-		}
 		.decl_assign {
 			c.allocate_var(left.name, 8, i64(int_lit.val.int()))
 		}
@@ -2324,56 +2291,23 @@ fn (mut c Amd64) assign_ident_int_lit(node ast.AssignStmt, i i32, int_lit ast.In
 			c.mov64(Amd64Register.rax, i64(int_lit.val.int()))
 			c.mov_reg_to_var(left, Amd64Register.rax)
 		}
-		.left_shift_assign {
-			c.mov_var_to_reg(Amd64Register.rax, left)
-			c.mov64(Amd64Register.rcx, i64(int_lit.val.int()))
-			c.shl_reg(.rax, .rcx)
-			c.mov_reg_to_var(left, Amd64Register.rax)
-		}
-		.right_shift_assign {
-			c.mov_var_to_reg(Amd64Register.rax, left)
-			c.mov64(Amd64Register.rcx, i64(int_lit.val.int()))
-			c.sar_reg(.rax, .rcx)
-			c.mov_reg_to_var(left, Amd64Register.rax)
-		}
-		.unsigned_right_shift_assign {
-			c.mov_var_to_reg(Amd64Register.rax, left)
-			c.mov64(Amd64Register.rcx, i64(int_lit.val.int()))
-			c.shr_reg(.rax, .rcx)
-			c.mov_reg_to_var(left, Amd64Register.rax)
-		}
-		.xor_assign {
-			c.mov_var_to_reg(Amd64Register.rax, left)
-			c.mov64(Amd64Register.rcx, i64(int_lit.val.int()))
-			c.bitxor_reg(.rax, .rcx)
-			c.mov_reg_to_var(left, Amd64Register.rax)
-		}
-		.or_assign {
-			c.mov_var_to_reg(Amd64Register.rax, left)
-			c.mov64(Amd64Register.rcx, i64(int_lit.val.int()))
-			c.bitor_reg(.rax, .rcx)
-			c.mov_reg_to_var(left, Amd64Register.rax)
-		}
-		.and_assign {
-			c.mov_var_to_reg(Amd64Register.rax, left)
-			c.mov64(Amd64Register.rcx, i64(int_lit.val.int()))
-			c.bitand_reg(.rax, .rcx)
-			c.mov_reg_to_var(left, Amd64Register.rax)
-		}
 		.boolean_and_assign {
 			c.mov_var_to_reg(Amd64Register.rax, left)
-			c.mov64(Amd64Register.rcx, i64(int_lit.val.int()))
-			c.bitand_reg(.rax, .rcx)
+			c.mov64(Amd64Register.rbx, i64(int_lit.val.int()))
+			c.bitand_reg(.rax, .rbx)
 			c.mov_reg_to_var(left, Amd64Register.rax)
 		}
 		.boolean_or_assign {
 			c.mov_var_to_reg(Amd64Register.rax, left)
-			c.mov64(Amd64Register.rcx, i64(int_lit.val.int()))
-			c.bitor_reg(.rax, .rcx)
+			c.mov64(Amd64Register.rbx, i64(int_lit.val.int()))
+			c.bitor_reg(.rax, .rbx)
 			c.mov_reg_to_var(left, Amd64Register.rax)
 		}
 		else {
-			c.g.n_error('${@LOCATION} unexpected assignment op ${node.op}')
+			c.mov_var_to_reg(Amd64Register.rax, left)
+			c.mov64(Amd64Register.rbx, i64(int_lit.val.int()))
+			c.apply_op_int(.rax, .rbx, node.op)
+			c.mov_reg_to_var(left, Amd64Register.rax)
 		}
 	}
 }
@@ -2591,19 +2525,26 @@ fn (mut c Amd64) assign_ident_right_expr(node ast.AssignStmt, i i32, right ast.E
 
 					c.mov_ssereg_to_var(ident, .xmm1)
 				} else if left_type.is_int() {
-					c.mov_var_to_reg(Amd64Register.rbx, ident)
-
-					match node.op {
-						.plus_assign { c.add_reg(.rbx, .rax) }
-						.minus_assign { c.sub_reg(.rbx, .rax) }
-						.div_assign { c.div_reg(.rbx, .rax) }
-						.mult_assign { c.mul_reg(.rbx, .rax) }
-						else { c.g.n_error('${@LOCATION} unexpected assignment operator ${node.op} for i32') }
-					}
-
-					c.mov_reg_to_var(ident, Amd64Register.rbx)
+					c.mov_reg(Amd64Register.rbx, Amd64Register.rax)
+					c.mov_var_to_reg(Amd64Register.rax, ident)
+					c.apply_op_int(.rax, .rbx, node.op)
+					c.mov_reg_to_var(ident, Amd64Register.rax)
 				} else {
-					c.g.n_error('${@LOCATION} assignment arithmetic not implemented for type ${node.left_types[i]}')
+					match node.op {
+						.boolean_and_assign {
+							c.mov_var_to_reg(Amd64Register.rbx, ident)
+							c.bitand_reg(.rbx, .rax)
+							c.mov_reg_to_var(ident, Amd64Register.rbx)
+						}
+						.boolean_or_assign {
+							c.mov_var_to_reg(Amd64Register.rbx, ident)
+							c.bitor_reg(.rbx, .rax)
+							c.mov_reg_to_var(ident, Amd64Register.rbx)
+						}
+						else {
+							c.g.n_error('${@LOCATION} assignment arithmetic not implemented for type ${node.left_types[i]}')
+						}
+					}
 				}
 			}
 		}
@@ -2631,19 +2572,26 @@ fn (mut c Amd64) assign_ident_right_expr(node ast.AssignStmt, i i32, right ast.E
 
 				c.mov_ssereg_to_var(ident, .xmm1)
 			} else if left_type.is_int() {
-				c.mov_var_to_reg(Amd64Register.rbx, ident)
-
-				match node.op {
-					.plus_assign { c.add_reg(.rbx, .rax) }
-					.minus_assign { c.sub_reg(.rbx, .rax) }
-					.div_assign { c.div_reg(.rbx, .rax) }
-					.mult_assign { c.mul_reg(.rbx, .rax) }
-					else { c.g.n_error('${@LOCATION} unexpected assignment operator ${node.op} for i32') }
-				}
-
-				c.mov_reg_to_var(ident, Amd64Register.rbx)
+				c.mov_reg(Amd64Register.rbx, Amd64Register.rax)
+				c.mov_var_to_reg(Amd64Register.rax, ident)
+				c.apply_op_int(.rax, .rbx, node.op)
+				c.mov_reg_to_var(ident, Amd64Register.rax)
 			} else {
-				c.g.n_error('${@LOCATION} assignment arithmetic not implemented for type ${node.left_types[i]}')
+				match node.op {
+					.boolean_and_assign {
+						c.mov_var_to_reg(Amd64Register.rbx, ident)
+						c.bitand_reg(.rbx, .rax)
+						c.mov_reg_to_var(ident, Amd64Register.rbx)
+					}
+					.boolean_or_assign {
+						c.mov_var_to_reg(Amd64Register.rbx, ident)
+						c.bitor_reg(.rbx, .rax)
+						c.mov_reg_to_var(ident, Amd64Register.rbx)
+					}
+					else {
+						c.g.n_error('${@LOCATION} assignment arithmetic not implemented for type ${node.left_types[i]}')
+					}
+				}
 			}
 		}
 	}
@@ -2680,6 +2628,59 @@ fn (mut c Amd64) assign_ident_right_expr(node ast.AssignStmt, i i32, right ast.E
 	}*/
 }
 
+// /!\ for div, mul, mod the left value should always be .rax
+fn (mut c Amd64) apply_op_int(left_value Amd64Register, right_value Amd64Register, op token.Kind) {
+	match op {
+		.plus_assign {
+			c.add_reg(left_value, right_value)
+		}
+		.minus_assign {
+			c.sub_reg(left_value, right_value)
+		}
+		.div_assign {
+			if left_value != .rax {
+				c.g.n_error('@{LOCATION} div always operates on rax')
+			}
+			c.mov(Amd64Register.rdx, i32(0)) // 64bits IDIV uses RDX:RAX
+			c.div_reg_rax(right_value)
+		}
+		.mult_assign {
+			if left_value != .rax {
+				c.g.n_error('@{LOCATION} mul always operates on rax')
+			}
+			c.mul_reg_rax(right_value)
+		}
+		.xor_assign {
+			c.bitxor_reg(left_value, right_value)
+		}
+		.mod_assign {
+			if left_value != .rax {
+				c.g.n_error('@{LOCATION} mod always operates on rax')
+			}
+			c.mov(Amd64Register.rdx, i32(0)) // 64bits IDIV uses RDX:RAX
+			c.mod_reg_rax(right_value)
+		}
+		.or_assign {
+			c.bitor_reg(left_value, right_value)
+		}
+		.and_assign {
+			c.bitand_reg(left_value, right_value)
+		}
+		.right_shift_assign {
+			c.shr_reg(left_value, right_value)
+		}
+		.left_shift_assign {
+			c.shl_reg(left_value, right_value)
+		}
+		.unsigned_right_shift_assign {
+			c.sar_reg(left_value, right_value)
+		}
+		else {
+			c.g.n_error('${@LOCATION} unexpected operator ${op} for int')
+		}
+	}
+}
+
 fn (mut c Amd64) gen_type_promotion(from ast.Type, to ast.Type, option Amd64RegisterOption) {
 	if !to.is_pure_float() {
 		return
@@ -3077,52 +3078,6 @@ fn (mut c Amd64) assign_stmt(node ast.AssignStmt) {
 					.decl_assign, .assign {
 						c.mov_store(.rbx, .rcx, size)
 					}
-					.plus_assign {
-						c.add_reg(.rax, .rcx)
-						c.mov_store(.rbx, .rax, size)
-					}
-					.minus_assign {
-						c.sub_reg(.rax, .rcx)
-						c.mov_store(.rbx, .rax, size)
-					}
-					.and_assign {
-						c.bitand_reg(.rax, .rcx)
-						c.mov_store(.rbx, .rax, size)
-					}
-					.mod_assign {
-						c.mov(Amd64Register.rdx, i32(0)) // 64bits IDIV uses RDX:RAX
-						c.mod_reg(.rax, .rcx)
-						c.mov_store(.rbx, .rax, size)
-					}
-					.mult_assign {
-						c.mul_reg(.rax, .rcx)
-						c.mov_store(.rbx, .rax, size)
-					}
-					.div_assign {
-						c.mov(Amd64Register.rdx, i32(0)) // 64bits IDIV uses RDX:RAX
-						c.div_reg(.rax, .rcx)
-						c.mov_store(.rbx, .rax, size)
-					}
-					.xor_assign {
-						c.bitxor_reg(.rax, .rcx)
-						c.mov_store(.rbx, .rax, size)
-					}
-					.or_assign {
-						c.bitor_reg(.rax, .rcx)
-						c.mov_store(.rbx, .rax, size)
-					}
-					.right_shift_assign {
-						c.shr_reg(.rax, .rcx)
-						c.mov_store(.rbx, .rax, size)
-					}
-					.left_shift_assign {
-						c.shl_reg(.rax, .rcx)
-						c.mov_store(.rbx, .rax, size)
-					}
-					.unsigned_right_shift_assign {
-						c.sar_reg(.rax, .rcx)
-						c.mov_store(.rbx, .rax, size)
-					}
 					.boolean_and_assign {
 						c.bitand_reg(.rax, .rcx)
 						c.mov_store(.rbx, .rax, size)
@@ -3132,7 +3087,8 @@ fn (mut c Amd64) assign_stmt(node ast.AssignStmt) {
 						c.mov_store(.rbx, .rax, size)
 					}
 					else {
-						c.g.n_error('${@LOCATION} Unsupported assign instruction (${node.op})')
+						c.apply_op_int(.rax, .rcx, node.op)
+						c.mov_store(.rbx, .rax, size)
 					}
 				}
 			} else if var_type.is_pure_float() {
@@ -4289,7 +4245,7 @@ fn (mut c Amd64) convert_int_to_string(a Register, b Register) {
 
 	c.mov(Amd64Register.rdx, 0) // upperhalf of the dividend
 	c.mov(Amd64Register.rbx, 10)
-	c.div_reg(.rax, .rbx) // rax will be the result of the division
+	c.div_reg_rax(.rbx) // rax will be the result of the division
 	c.add8(.rdx, i32(`0`)) // rdx is the remainder, add 48 to convert it into it's ascii representation
 
 	c.mov_store(.rdi, .rdx, ._8)
diff --git a/vlib/v/gen/native/tests/assign.vv b/vlib/v/gen/native/tests/assign.vv
index 6c6e353d07..a45425ce8b 100644
--- a/vlib/v/gen/native/tests/assign.vv
+++ b/vlib/v/gen/native/tests/assign.vv
@@ -7,6 +7,88 @@ fn main() {
 	test_alias(100, 9)
 	test_plus_assign()
 	test_minus_assign()
+	op_assigns_test()
+	if_expr_op_assigns_test()
+}
+
+fn if_expr_op_assigns_test() {
+	mut b := 1
+	one := 1
+	two := 2
+	three := 3
+	four := 4
+	five := 5
+	ten := 10
+	b += if false {0} else {one}
+	b -= if false {0} else {one}
+	assert b == 1
+	b |= if false {0} else {two}
+	assert b == 3
+	b &= if false {0} else {one}
+	assert b == 1
+	b ^= if false {0} else {five}
+	assert b == 4
+	b %= if false {0} else {three}
+	assert b == 1
+	b *= if false {0} else {ten}
+	b /= if false {0} else {ten}
+	assert b == 1
+	b <<= if false {0} else {four}
+	b >>>= if false {0} else {two}
+	b >>= if false {0} else {two}
+	assert b == 1
+
+	mut var := true
+	t := true
+	f := false
+	var &&= if false {f} else {t}
+	assert var == true
+	var &&= if false {t} else {f}
+	assert var == false
+	var ||= if false {f} else {t}
+	assert var == true
+	var ||= if false {t} else {f}
+	assert var == true
+}
+
+fn op_assigns_test() {
+	mut b := 1
+	one := 1
+	two := 2
+	three := 3
+	four := 4
+	five := 5
+	ten := 10
+	b += one
+	b -= one
+	assert b == 1
+	b |= two
+	assert b == 3
+	b &= one
+	assert b == 1
+	b ^= five
+	assert b == 4
+	b %= three
+	assert b == 1
+	b *= ten
+	b /= ten
+	assert b == 1
+	b <<= four
+	b >>>= two
+	b >>= two
+	assert b == 1
+
+	mut var := true
+	t := true
+	f := false
+	var &&= t
+	assert var == true
+	var &&= f
+	assert var == false
+	var ||= t
+	assert var == true
+	var ||= f
+	assert var == true
 }
 
 fn test_minus_assign() {

From d73ebc1aca582d13af2d8708aab2088d7921de12 Mon Sep 17 00:00:00 2001
From: Delyan Angelov <delian66@gmail.com>
Date: Thu, 11 Sep 2025 13:18:56 +0300
Subject: [PATCH 2/5] v.ast: add a `mod` field to ast.FnTypeDecl too

---
 cmd/tools/vast/vast.v  | 1 +
 vlib/v/ast/ast.v       | 1 +
 vlib/v/parser/parser.v | 1 +
 3 files changed, 3 insertions(+)

diff --git a/cmd/tools/vast/vast.v b/cmd/tools/vast/vast.v
index d38a95accb..67394cf1f9 100644
--- a/cmd/tools/vast/vast.v
+++ b/cmd/tools/vast/vast.v
@@ -897,6 +897,7 @@ fn (t Tree) fn_type_decl(node ast.FnTypeDecl) &Node {
 	mut obj := create_object()
 	obj.add_terse('ast_type', t.string_node('FnTypeDecl'))
 	obj.add_terse('name', t.string_node(node.name))
+	obj.add_terse('mod', t.string_node(node.mod))
 	obj.add_terse('is_pub', t.bool_node(node.is_pub))
 	obj.add_terse('typ', t.type_node(node.typ))
 	obj.add('pos', t.pos(node.pos))
diff --git a/vlib/v/ast/ast.v b/vlib/v/ast/ast.v
index cdf72c96f7..b215349290 100644
--- a/vlib/v/ast/ast.v
+++ b/vlib/v/ast/ast.v
@@ -1522,6 +1522,7 @@ pub mut:
 pub struct FnTypeDecl {
 pub:
 	name          string
+	mod           string
 	is_pub        bool
 	typ           Type
 	pos           token.Pos
diff --git a/vlib/v/parser/parser.v b/vlib/v/parser/parser.v
index c762ce7f10..24c7fda1fc 100644
--- a/vlib/v/parser/parser.v
+++ b/vlib/v/parser/parser.v
@@ -2782,6 +2782,7 @@ fn (mut p Parser) type_decl() ast.TypeDecl {
 		p.attrs = []
 		return ast.FnTypeDecl{
 			name:          fn_name
+			mod:           p.mod
 			is_pub:        is_pub
 			typ:           fn_type
 			pos:           decl_pos

From 04e79e7b2a96bed2592d7939258ff455be82db16 Mon Sep 17 00:00:00 2001
From: CreeperFace <165158232+dy-tea@users.noreply.github.com>
Date: Thu, 11 Sep 2025 21:33:43 +0100
Subject: [PATCH 3/5] checker: prevent usage of imported module name prefix as
 identifier names, to avoid cgen collisions (#25280)

---
 vlib/v/checker/assign.v                       |  1 +
 vlib/v/checker/checker.v                      | 35 ++++++++++++++-----
 vlib/v/checker/fn.v                           |  1 +
 .../tests/clash_ident_module_name_prefix.out  | 28 +++++++++++++++
 .../tests/clash_ident_module_name_prefix.vv   | 23 ++++++++++++
 5 files changed, 80 insertions(+), 8 deletions(-)
 create mode 100644 vlib/v/checker/tests/clash_ident_module_name_prefix.out
 create mode 100644 vlib/v/checker/tests/clash_ident_module_name_prefix.vv

diff --git a/vlib/v/checker/assign.v b/vlib/v/checker/assign.v
index e9fc1495ab..af0b4b2633 100644
--- a/vlib/v/checker/assign.v
+++ b/vlib/v/checker/assign.v
@@ -444,6 +444,7 @@ fn (mut c Checker) assign_stmt(mut node ast.AssignStmt) {
 						if c.check_import_sym_conflict(left.name) {
 							c.error('duplicate of an import symbol `${left.name}`', left.pos)
 						}
+						c.check_module_name_conflict(left.name, left.pos)
 					}
 					if node.op == .assign && left_type.has_flag(.option) && right is ast.UnsafeExpr
 						&& right.expr.is_nil() {
diff --git a/vlib/v/checker/checker.v b/vlib/v/checker/checker.v
index 34b2cb8fc2..79b6a2cdd9 100644
--- a/vlib/v/checker/checker.v
+++ b/vlib/v/checker/checker.v
@@ -137,14 +137,15 @@ mut:
 	inside_assign                    bool
 	// doing_line_info                  int    // a quick single file run when called with v -line-info (contains line nr to inspect)
 	// doing_line_path                  string // same, but stores the path being parsed
-	is_index_assign   bool
-	comptime_call_pos int                      // needed for correctly checking use before decl for templates
-	goto_labels       map[string]ast.GotoLabel // to check for unused goto labels
-	enum_data_type    ast.Type
-	field_data_type   ast.Type
-	variant_data_type ast.Type
-	fn_return_type    ast.Type
-	orm_table_fields  map[string][]ast.StructField // known table structs
+	is_index_assign    bool
+	comptime_call_pos  int                      // needed for correctly checking use before decl for templates
+	goto_labels        map[string]ast.GotoLabel // to check for unused goto labels
+	enum_data_type     ast.Type
+	field_data_type    ast.Type
+	variant_data_type  ast.Type
+	fn_return_type     ast.Type
+	orm_table_fields   map[string][]ast.StructField // known table structs
+	short_module_names []string                     // to check for function names colliding with module functions
 
 	v_current_commit_hash string // same as old C.V_CURRENT_COMMIT_HASH
 	assign_stmt_attr      string // for `x := [1,2,3] @[freed]`
@@ -331,6 +332,14 @@ pub fn (mut c Checker) change_current_file(file &ast.File) {
 	c.vmod_file_content = ''
 	c.mod = file.mod.name
 	c.is_generated = file.is_generated
+	c.short_module_names = ['builtin']
+	for import_sym in c.file.imports {
+		c.short_module_names << if import_sym.alias == '' {
+			import_sym.mod.all_after_last('.')
+		} else {
+			import_sym.alias
+		}
+	}
 }
 
 pub fn (mut c Checker) check_files(ast_files []&ast.File) {
@@ -5790,6 +5799,16 @@ fn (c &Checker) check_import_sym_conflict(ident string) bool {
 	return false
 }
 
+fn (mut c Checker) check_module_name_conflict(ident string, pos token.Pos) {
+	if ident.contains('__') {
+		prefix := ident.all_before('__')
+		if prefix in c.short_module_names {
+			c.error('identifier cannot use prefix `${prefix}__` of imported module `${prefix}`',
+				pos)
+		}
+	}
+}
+
 // update_unresolved_fixed_sizes updates the unresolved type symbols for array fixed return type and alias type.
 pub fn (mut c Checker) update_unresolved_fixed_sizes() {
 	for mut stmt in c.unresolved_fixed_sizes {
diff --git a/vlib/v/checker/fn.v b/vlib/v/checker/fn.v
index 12b2d8a357..0c2b338fa4 100644
--- a/vlib/v/checker/fn.v
+++ b/vlib/v/checker/fn.v
@@ -104,6 +104,7 @@ fn (mut c Checker) fn_decl(mut node ast.FnDecl) {
 		if !node.is_method && node.mod == 'main' && node.short_name in c.table.builtin_pub_fns {
 			c.error('cannot redefine builtin public function `${node.short_name}`', node.pos)
 		}
+		c.check_module_name_conflict(node.short_name, node.pos)
 	}
 	if node.name == 'main.main' {
 		c.main_fn_decl_node = *node
diff --git a/vlib/v/checker/tests/clash_ident_module_name_prefix.out b/vlib/v/checker/tests/clash_ident_module_name_prefix.out
new file mode 100644
index 0000000000..4a756ca522
--- /dev/null
+++ b/vlib/v/checker/tests/clash_ident_module_name_prefix.out
@@ -0,0 +1,28 @@
+vlib/v/checker/tests/clash_ident_module_name_prefix.vv:7:1: error: identifier cannot use prefix `builtin__` of imported module `builtin`
+    5 | // os is not imported so the os__ prefix should not produce an error
+    6 |
+    7 | fn builtin__string_str() {
+      | ~~~~~~~~~~~~~~~~~~~~~~~~
+    8 | }
+    9 |
+vlib/v/checker/tests/clash_ident_module_name_prefix.vv:10:1: error: identifier cannot use prefix `time__` of imported module `time`
+    8 | }
+    9 |
+   10 | fn time__utc() {
+      | ~~~~~~~~~~~~~~
+   11 | }
+   12 |
+vlib/v/checker/tests/clash_ident_module_name_prefix.vv:17:2: error: identifier cannot use prefix `builtin__` of imported module `builtin`
+   15 |
+   16 | fn main() {
+   17 |     builtin__string_str := 'Hello V!'.str()
+      |     ~~~~~~~~~~~~~~~~~~~
+   18 |     time__now := time.now()
+   19 |     os__log := 'Hello V!'
+vlib/v/checker/tests/clash_ident_module_name_prefix.vv:18:2: error: identifier cannot use prefix `time__` of imported module `time`
+   16 | fn main() {
+   17 |     builtin__string_str := 'Hello V!'.str()
+   18 |     time__now := time.now()
+      |     ~~~~~~~~~
+   19 |     os__log := 'Hello V!'
+   20 |     println(builtin__string_str)
\ No newline at end of file
diff --git a/vlib/v/checker/tests/clash_ident_module_name_prefix.vv b/vlib/v/checker/tests/clash_ident_module_name_prefix.vv
new file mode 100644
index 0000000000..738dfde11f
--- /dev/null
+++ b/vlib/v/checker/tests/clash_ident_module_name_prefix.vv
@@ -0,0 +1,23 @@
+import time
+
+// builtin__ prefix should always produce an error
+// time is imported so the time__ prefix should always produce an error
+// os is not imported so the os__ prefix should not produce an error
+
+fn builtin__string_str() {
+}
+
+fn time__utc() {
+}
+
+fn os__getwd() {
+}
+
+fn main() {
+	builtin__string_str := 'Hello V!'.str()
+	time__now := time.now()
+	os__log := 'Hello V!'
+	println(builtin__string_str)
+	println(time__now)
+	println(os__log)
+}

From 56f20d1ff8ce8c1f68bb3cee1bb241e7e2f45bb3 Mon Sep 17 00:00:00 2001
From: blackshirt <blackshirt@users.noreply.github.com>
Date: Fri, 12 Sep 2025 03:36:11 +0700
Subject: [PATCH 4/5] x.crypto.ascon: small cleanups and optimization (#25284)

---
 vlib/x/crypto/ascon/ascon.v  | 19 +++++++++++++------
 vlib/x/crypto/ascon/digest.v | 33 ++++++++++++++++++++++-----------
 vlib/x/crypto/ascon/util.v   | 16 +++++++++++++---
 3 files changed, 48 insertions(+), 20 deletions(-)

diff --git a/vlib/x/crypto/ascon/ascon.v b/vlib/x/crypto/ascon/ascon.v
index 8bb1b1977a..1ebd5bab84 100644
--- a/vlib/x/crypto/ascon/ascon.v
+++ b/vlib/x/crypto/ascon/ascon.v
@@ -41,6 +41,9 @@ fn ascon_pnr(mut s State, nr int) {
 	if nr < 1 || nr > 16 {
 		panic('Invalid round number')
 	}
+	// Allocate temporary vars to reduce allocation within loop
+	mut x0 := u64(0)
+	mut y0 := u64(0)
 	// Ascon permutation routine
 	for i := max_nr_perm - nr; i < max_nr_perm; i++ {
 		// 3.2 Constant-Addition Layer step
@@ -56,18 +59,22 @@ fn ascon_pnr(mut s State, nr int) {
 		s.e0 ^= s.e4
 		s.e4 ^= s.e3
 		s.e2 ^= s.e1
-
+		// Set temp vars to values
+		x0 = s.e0
+		y0 = s.e4 ^ (~s.e0 & s.e1)
+		/*
 		t0 := s.e4 ^ (~s.e0 & s.e1)
 		t1 := s.e0 ^ (~s.e1 & s.e2)
 		t2 := s.e1 ^ (~s.e2 & s.e3)
 		t3 := s.e2 ^ (~s.e3 & s.e4)
 		t4 := s.e3 ^ (~s.e4 & s.e0)
+		*/
 
-		s.e0 = t1
-		s.e1 = t2
-		s.e2 = t3
-		s.e3 = t4
-		s.e4 = t0
+		s.e0 = s.e0 ^ (~s.e1 & s.e2) // t1
+		s.e1 = s.e1 ^ (~s.e2 & s.e3) // t2
+		s.e2 = s.e2 ^ (~s.e3 & s.e4) // t3
+		s.e3 = s.e3 ^ (~s.e4 & x0) // t4, change s.e0 to x0
+		s.e4 = y0
 
 		s.e1 ^= s.e0
 		s.e0 ^= s.e4
diff --git a/vlib/x/crypto/ascon/digest.v b/vlib/x/crypto/ascon/digest.v
index 89a7dac7e1..07ee9ad303 100644
--- a/vlib/x/crypto/ascon/digest.v
+++ b/vlib/x/crypto/ascon/digest.v
@@ -135,20 +135,32 @@ fn (mut d Digest) squeeze(mut dst []u8) int {
 }
 
 @[direct_array_access; inline]
-fn ascon_generic_hash(mut s State, msg_ []u8, size int) []u8 {
+fn ascon_generic_hash(mut s State, msg []u8, size int) []u8 {
 	// Assumed state was correctly initialized
 	// Absorbing the message
-	mut msg := msg_.clone()
-	for msg.len >= block_size {
-		s.e0 ^= binary.little_endian_u64(msg[0..block_size])
-		unsafe {
-			msg = msg[block_size..]
+	mut pos := 0
+	// Check if msg has non-null length, if yes, absorb it.
+	// Otherwise, just pad it
+	if _likely_(msg.len > 0) {
+		mut msg_len := msg.len
+		for msg_len >= block_size {
+			s.e0 ^= binary.little_endian_u64(msg[pos..pos + block_size])
+			pos += block_size
+			msg_len -= block_size
+			ascon_pnr(mut s, ascon_prnd_12)
 		}
-		ascon_pnr(mut s, ascon_prnd_12)
+		// Absorb the last partial message block
+		last_block := unsafe { msg[pos..] }
+		s.e0 ^= u64(0x01) << (8 * last_block.len) // pad(last_block.len)
+		if last_block.len > 0 {
+			s.e0 ^= load_bytes(last_block, last_block.len)
+		}
+	} else {
+		// Otherwise, just pad it
+		s.e0 ^= u64(0x01)
 	}
-	// Absorb the last partial message block
-	s.e0 ^= load_bytes(msg, msg.len)
-	s.e0 ^= pad(msg.len)
+	// reset pos
+	pos = 0
 
 	// Squeezing phase
 	//
@@ -156,7 +168,6 @@ fn ascon_generic_hash(mut s State, msg_ []u8, size int) []u8 {
 	// permutation 𝐴𝑠𝑐𝑜𝑛-𝑝[12] to the state:
 	ascon_pnr(mut s, ascon_prnd_12)
 	mut out := []u8{len: size}
-	mut pos := 0
 	mut clen := out.len
 	for clen >= block_size {
 		binary.little_endian_put_u64(mut out[pos..pos + 8], s.e0)
diff --git a/vlib/x/crypto/ascon/util.v b/vlib/x/crypto/ascon/util.v
index 345683ea66..97e70d5e98 100644
--- a/vlib/x/crypto/ascon/util.v
+++ b/vlib/x/crypto/ascon/util.v
@@ -83,13 +83,23 @@ fn set_byte(b u8, i int) u64 {
 fn load_bytes(bytes []u8, n int) u64 {
 	mut x := u64(0)
 	for i := 0; i < n; i++ {
-		x |= set_byte(bytes[i], i)
+		// This is the same way to store bytes in little-endian way
+		//		x |= u64(bytes[0]) << 8*0  // LSB at lowest index
+		//		x |= u64(bytes[1]) << 8*1
+		// 		x |= u64(bytes[2]) << 8*2
+		//		x |= u64(bytes[3]) << 8*3
+		//		...etc
+		// 		x |= u64(bytes[7]) << 8*7  // MSB at highest index
+		x |= u64(bytes[i]) << (8 * i)
 	}
-	return u64le(x)
+	// No need to cast with u64le, its alread le
+	return x
 }
 
+@[direct_array_access]
 fn store_bytes(mut out []u8, x u64, n int) {
 	for i := 0; i < n; i++ {
-		out[i] = get_byte(x, i)
+		// use underlying get_byte directly
+		out[i] = u8(x >> (8 * i))
 	}
 }

From a8d200ac0ecdb264f78c4a6626ca4533cad5dddd Mon Sep 17 00:00:00 2001
From: Larsimusrex <lars.luis@gmail.com>
Date: Fri, 12 Sep 2025 09:57:15 +0200
Subject: [PATCH 5/5] decoder2: improve enum decoding; fix handling of required
 fields at the end of a json string (#25289)

---
 vlib/x/json2/decoder2/attributes_test.v       |  10 +
 vlib/x/json2/decoder2/decode.v                | 272 ++++++++++--------
 .../x/json2/decoder2/tests/decode_enum_test.v |  95 ++++++
 .../tests/decode_escaped_string_test.v        |   2 +-
 4 files changed, 258 insertions(+), 121 deletions(-)
 create mode 100644 vlib/x/json2/decoder2/tests/decode_enum_test.v

diff --git a/vlib/x/json2/decoder2/attributes_test.v b/vlib/x/json2/decoder2/attributes_test.v
index 8458c63759..8fe9d9ce0a 100644
--- a/vlib/x/json2/decoder2/attributes_test.v
+++ b/vlib/x/json2/decoder2/attributes_test.v
@@ -38,6 +38,16 @@ struct StruWithRequiredAttribute {
 	b                 int
 }
 
+struct Foo {
+	a int @[required]
+}
+
+fn test_last_field_requiered() {
+	assert json.decode[Foo]('{"a":0}')! == Foo{
+		a: 0
+	}
+}
+
 fn test_skip_and_rename_attributes() {
 	assert json.decode[StruWithJsonAttribute]('{"name": "hola1", "a": 2, "b": 3}')! == StruWithJsonAttribute{
 		a:     2
diff --git a/vlib/x/json2/decoder2/decode.v b/vlib/x/json2/decoder2/decode.v
index d0a5d1b752..f5e61a50d7 100644
--- a/vlib/x/json2/decoder2/decode.v
+++ b/vlib/x/json2/decoder2/decode.v
@@ -38,7 +38,7 @@ struct StructFieldInfo {
 	is_required    bool
 	is_raw         bool
 mut:
-	decoded_with_value_info_node &Node[ValueInfo] = unsafe { nil }
+	is_decoded bool
 }
 
 // Decoder represents a JSON decoder.
@@ -368,105 +368,7 @@ fn (mut decoder Decoder) decode_value[T](mut val T) ! {
 		}
 	}
 	$if T.unaliased_typ is string {
-		string_info := decoder.current_node.value
-
-		if string_info.value_kind == .string {
-			mut string_buffer := []u8{cap: string_info.length} // might be too long but most json strings don't contain many escape characters anyways
-
-			mut buffer_index := 1
-			mut string_index := 1
-
-			for string_index < string_info.length - 1 {
-				current_byte := decoder.json[string_info.position + string_index]
-
-				if current_byte == `\\` {
-					// push all characters up to this point
-					unsafe {
-						string_buffer.push_many(decoder.json.str + string_info.position +
-							buffer_index, string_index - buffer_index)
-					}
-
-					string_index++
-
-					escaped_char := decoder.json[string_info.position + string_index]
-
-					string_index++
-
-					match escaped_char {
-						`/`, `"`, `\\` {
-							string_buffer << escaped_char
-						}
-						`b` {
-							string_buffer << `\b`
-						}
-						`f` {
-							string_buffer << `\f`
-						}
-						`n` {
-							string_buffer << `\n`
-						}
-						`r` {
-							string_buffer << `\r`
-						}
-						`t` {
-							string_buffer << `\t`
-						}
-						`u` {
-							unicode_point := rune(strconv.parse_uint(decoder.json[
-								string_info.position + string_index..string_info.position +
-								string_index + 4], 16, 32)!)
-
-							string_index += 4
-
-							if unicode_point < 0xD800 { // normal utf-8
-								string_buffer << unicode_point.bytes()
-							} else if unicode_point >= 0xDC00 { // trail surrogate -> invalid
-								decoder.decode_error('Got trail surrogate: ${u32(unicode_point):04X} before head surrogate.')!
-							} else { // head surrogate -> treat as utf-16
-								if string_index > string_info.length - 6 {
-									decoder.decode_error('Expected a trail surrogate after a head surrogate, but got no valid escape sequence.')!
-								}
-								if decoder.json[string_info.position + string_index..
-									string_info.position + string_index + 2] != '\\u' {
-									decoder.decode_error('Expected a trail surrogate after a head surrogate, but got no valid escape sequence.')!
-								}
-
-								string_index += 2
-
-								unicode_point2 := rune(strconv.parse_uint(decoder.json[
-									string_info.position + string_index..string_info.position +
-									string_index + 4], 16, 32)!)
-
-								string_index += 4
-
-								if unicode_point2 < 0xDC00 {
-									decoder.decode_error('Expected a trail surrogate after a head surrogate, but got ${u32(unicode_point):04X}.')!
-								}
-
-								final_unicode_point := (unicode_point2 & 0x3FF) +
-									((unicode_point & 0x3FF) << 10) + 0x10000
-								string_buffer << final_unicode_point.bytes()
-							}
-						}
-						else {} // has already been checked
-					}
-
-					buffer_index = string_index
-				} else {
-					string_index++
-				}
-			}
-
-			// push the rest
-			unsafe {
-				string_buffer.push_many(decoder.json.str + string_info.position + buffer_index,
-					string_index - buffer_index)
-			}
-
-			val = string_buffer.bytestr()
-		} else {
-			return decoder.decode_error('Expected string, but got ${string_info.value_kind}')
-		}
+		decoder.decode_string(mut val)!
 	} $else $if T.unaliased_typ is $sumtype {
 		decoder.decode_sumtype(mut val)!
 		return
@@ -509,7 +411,7 @@ fn (mut decoder Decoder) decode_value[T](mut val T) ! {
 			for attr in field.attrs {
 				if attr.starts_with('json:') {
 					if attr.len <= 6 {
-						return decoder.decode_error('`json` attribute must have an argument')
+						decoder.decode_error('`json` attribute must have an argument')!
 					}
 					json_name_str = unsafe { attr.str + 6 }
 					json_name_len = attr.len - 6
@@ -615,9 +517,9 @@ fn (mut decoder Decoder) decode_value[T](mut val T) ! {
 
 										if current_field_info.value.is_skip {
 											if current_field_info.value.is_required == false {
-												return decoder.decode_error('This should not happen. Please, file a bug. `skip` field should not be processed here without a `required` attribute')
+												decoder.decode_error('This should not happen. Please, file a bug. `skip` field should not be processed here without a `required` attribute')!
 											}
-											current_field_info.value.decoded_with_value_info_node = decoder.current_node
+											current_field_info.value.is_decoded = true
 											if decoder.current_node != unsafe { nil } {
 												decoder.current_node = decoder.current_node.next
 											}
@@ -627,7 +529,7 @@ fn (mut decoder Decoder) decode_value[T](mut val T) ! {
 										if current_field_info.value.is_raw {
 											$if field.unaliased_typ is $enum {
 												// workaround to avoid the error: enums can only be assigned `int` values
-												return decoder.decode_error('`raw` attribute cannot be used with enum fields')
+												decoder.decode_error('`raw` attribute cannot be used with enum fields')!
 											} $else $if field.typ is ?string {
 												position := decoder.current_node.value.position
 												end := position + decoder.current_node.value.length
@@ -659,7 +561,7 @@ fn (mut decoder Decoder) decode_value[T](mut val T) ! {
 													decoder.current_node = decoder.current_node.next
 												}
 											} $else {
-												return decoder.decode_error('`raw` attribute can only be used with string fields')
+												decoder.decode_error('`raw` attribute can only be used with string fields')!
 											}
 										} else {
 											$if field.typ is $option {
@@ -682,7 +584,7 @@ fn (mut decoder Decoder) decode_value[T](mut val T) ! {
 												decoder.decode_value(mut val.$(field.name))!
 											}
 										}
-										current_field_info.value.decoded_with_value_info_node = decoder.current_node
+										current_field_info.value.is_decoded = true
 										break
 									}
 								}
@@ -705,15 +607,15 @@ fn (mut decoder Decoder) decode_value[T](mut val T) ! {
 					current_field_info = current_field_info.next
 					continue
 				}
-				if current_field_info.value.decoded_with_value_info_node == unsafe { nil } {
-					return decoder.decode_error('missing required field `${unsafe {
+				if !current_field_info.value.is_decoded {
+					decoder.decode_error('missing required field `${unsafe {
 						tos(current_field_info.value.field_name_str, current_field_info.value.field_name_len)
-					}}`')
+					}}`')!
 				}
 				current_field_info = current_field_info.next
 			}
 		} else {
-			return decoder.decode_error('Expected object, but got ${struct_info.value_kind}')
+			decoder.decode_error('Expected object, but got ${struct_info.value_kind}')!
 		}
 		unsafe {
 			struct_fields_info.free()
@@ -723,14 +625,14 @@ fn (mut decoder Decoder) decode_value[T](mut val T) ! {
 		value_info := decoder.current_node.value
 
 		if value_info.value_kind != .boolean {
-			return decoder.decode_error('Expected boolean, but got ${value_info.value_kind}')
+			decoder.decode_error('Expected boolean, but got ${value_info.value_kind}')!
 		}
 
 		unsafe {
 			val = vmemcmp(decoder.json.str + value_info.position, true_in_string.str,
 				true_in_string.len) == 0
 		}
-	} $else $if T.unaliased_typ is $float || T.unaliased_typ is $int || T.unaliased_typ is $enum {
+	} $else $if T.unaliased_typ is $float || T.unaliased_typ is $int {
 		value_info := decoder.current_node.value
 
 		if value_info.value_kind == .number {
@@ -742,10 +644,12 @@ fn (mut decoder Decoder) decode_value[T](mut val T) ! {
 
 			unsafe { decoder.decode_number(&val)! }
 		} else {
-			return decoder.decode_error('Expected number, but got ${value_info.value_kind}')
+			decoder.decode_error('Expected number, but got ${value_info.value_kind}')!
 		}
+	} $else $if T.unaliased_typ is $enum {
+		decoder.decode_enum(mut val)!
 	} $else {
-		return decoder.decode_error('cannot decode value with ${typeof(val).name} type')
+		decoder.decode_error('cannot decode value with ${typeof(val).name} type')!
 	}
 
 	if decoder.current_node != unsafe { nil } {
@@ -753,6 +657,108 @@ fn (mut decoder Decoder) decode_value[T](mut val T) ! {
 	}
 }
 
+fn (mut decoder Decoder) decode_string[T](mut val T) ! {
+	string_info := decoder.current_node.value
+
+	if string_info.value_kind == .string {
+		mut string_buffer := []u8{cap: string_info.length} // might be too long but most json strings don't contain many escape characters anyways
+
+		mut buffer_index := 1
+		mut string_index := 1
+
+		for string_index < string_info.length - 1 {
+			current_byte := decoder.json[string_info.position + string_index]
+
+			if current_byte == `\\` {
+				// push all characters up to this point
+				unsafe {
+					string_buffer.push_many(decoder.json.str + string_info.position + buffer_index,
+						string_index - buffer_index)
+				}
+
+				string_index++
+
+				escaped_char := decoder.json[string_info.position + string_index]
+
+				string_index++
+
+				match escaped_char {
+					`/`, `"`, `\\` {
+						string_buffer << escaped_char
+					}
+					`b` {
+						string_buffer << `\b`
+					}
+					`f` {
+						string_buffer << `\f`
+					}
+					`n` {
+						string_buffer << `\n`
+					}
+					`r` {
+						string_buffer << `\r`
+					}
+					`t` {
+						string_buffer << `\t`
+					}
+					`u` {
+						unicode_point := rune(strconv.parse_uint(decoder.json[
+							string_info.position + string_index..string_info.position +
+							string_index + 4], 16, 32)!)
+
+						string_index += 4
+
+						if unicode_point < 0xD800 || unicode_point > 0xDFFF { // normal utf-8
+							string_buffer << unicode_point.bytes()
+						} else if unicode_point >= 0xDC00 { // trail surrogate -> invalid
+							decoder.decode_error('Got trail surrogate: ${u32(unicode_point):04X} before head surrogate.')!
+						} else { // head surrogate -> treat as utf-16
+							if string_index > string_info.length - 6 {
+								decoder.decode_error('Expected a trail surrogate after a head surrogate, but got no valid escape sequence.')!
+							}
+							if decoder.json[string_info.position + string_index..
+								string_info.position + string_index + 2] != '\\u' {
+								decoder.decode_error('Expected a trail surrogate after a head surrogate, but got no valid escape sequence.')!
+							}
+
+							string_index += 2
+
+							unicode_point2 := rune(strconv.parse_uint(decoder.json[
+								string_info.position + string_index..string_info.position +
+								string_index + 4], 16, 32)!)
+
+							string_index += 4
+
+							if unicode_point2 < 0xDC00 {
+								decoder.decode_error('Expected a trail surrogate after a head surrogate, but got ${u32(unicode_point):04X}.')!
+							}
+
+							final_unicode_point := (unicode_point2 & 0x3FF) +
+								((unicode_point & 0x3FF) << 10) + 0x10000
+							string_buffer << final_unicode_point.bytes()
+						}
+					}
+					else {} // has already been checked
+				}
+
+				buffer_index = string_index
+			} else {
+				string_index++
+			}
+		}
+
+		// push the rest
+		unsafe {
+			string_buffer.push_many(decoder.json.str + string_info.position + buffer_index,
+				string_index - buffer_index)
+		}
+
+		val = string_buffer.bytestr()
+	} else {
+		decoder.decode_error('Expected string, but got ${string_info.value_kind}')!
+	}
+}
+
 fn (mut decoder Decoder) decode_array[T](mut val []T) ! {
 	array_info := decoder.current_node.value
 
@@ -775,7 +781,7 @@ fn (mut decoder Decoder) decode_array[T](mut val []T) ! {
 			val << array_element
 		}
 	} else {
-		return decoder.decode_error('Expected array, but got ${array_info.value_kind}')
+		decoder.decode_error('Expected array, but got ${array_info.value_kind}')!
 	}
 }
 
@@ -819,7 +825,7 @@ fn (mut decoder Decoder) decode_map[K, V](mut val map[K]V) ! {
 			decoder.decode_value(mut val[key])!
 		}
 	} else {
-		return decoder.decode_error('Expected object, but got ${map_info.value_kind}')
+		decoder.decode_error('Expected object, but got ${map_info.value_kind}')!
 	}
 }
 
@@ -889,6 +895,36 @@ fn get_number_digits[T](num T) int {
 	}
 }
 
+fn (mut decoder Decoder) decode_enum[T](mut val T) ! {
+	enum_info := decoder.current_node.value
+
+	if enum_info.value_kind == .number {
+		mut result := 0
+		unsafe { decoder.decode_number(&result)! }
+
+		$for value in T.values {
+			if int(value.value) == result {
+				val = value.value
+				return
+			}
+		}
+		decoder.decode_error('Number value: `${result}` does not match any field in enum: ${typeof(val).name}')!
+	} else if enum_info.value_kind == .string {
+		mut result := ''
+		unsafe { decoder.decode_value(mut result)! }
+
+		$for value in T.values {
+			if value.name == result {
+				val = value.value
+				return
+			}
+		}
+		decoder.decode_error('String value: `${result}` does not match any field in enum: ${typeof(val).name}')!
+	}
+
+	decoder.decode_error('Expected number or string value for enum, got: ${enum_info.value_kind}')!
+}
+
 // use pointer instead of mut so enum cast works
 @[unsafe]
 fn (mut decoder Decoder) decode_number[T](val &T) ! {
@@ -904,10 +940,6 @@ fn (mut decoder Decoder) decode_number[T](val &T) ! {
 	$if T.unaliased_typ is $float {
 		*val = T(strconv.atof_quick(decoder.json[number_info.position..number_info.position +
 			number_info.length]))
-	} $else $if T.unaliased_typ is $enum {
-		mut result := 0
-		decoder.decode_number(&result)!
-		*val = T(result)
 	} $else { // this part is a minefield
 		mut is_negative := false
 		mut index := 0
diff --git a/vlib/x/json2/decoder2/tests/decode_enum_test.v b/vlib/x/json2/decoder2/tests/decode_enum_test.v
new file mode 100644
index 0000000000..9473ce1a7e
--- /dev/null
+++ b/vlib/x/json2/decoder2/tests/decode_enum_test.v
@@ -0,0 +1,95 @@
+import x.json2.decoder2 as json
+
+enum Bar {
+	a
+	b
+	c = 10
+}
+
+type BarAlias = Bar
+
+fn test_number_decode() {
+	assert json.decode[Bar]('0')! == Bar.a
+	assert json.decode[Bar]('1')! == Bar.b
+	assert json.decode[Bar]('10')! == Bar.c
+
+	assert json.decode[BarAlias]('0')! == Bar.a
+	assert json.decode[BarAlias]('1')! == Bar.b
+	assert json.decode[BarAlias]('10')! == Bar.c
+}
+
+fn test_number_decode_fails() {
+	if _ := json.decode[Bar]('2') {
+		assert false
+	} else {
+		if err is json.JsonDecodeError {
+			assert err.line == 1
+			assert err.character == 1
+			assert err.message == 'Data: Number value: `2` does not match any field in enum: &Bar'
+		}
+	}
+
+	if _ := json.decode[BarAlias]('2') {
+		assert false
+	} else {
+		if err is json.JsonDecodeError {
+			assert err.line == 1
+			assert err.character == 1
+			assert err.message == 'Data: Number value: `2` does not match any field in enum: &BarAlias'
+		}
+	}
+}
+
+fn test_string_decode() {
+	assert json.decode[Bar]('"a"')! == Bar.a
+	assert json.decode[Bar]('"b"')! == Bar.b
+	assert json.decode[Bar]('"c"')! == Bar.c
+
+	assert json.decode[BarAlias]('"a"')! == Bar.a
+	assert json.decode[BarAlias]('"b"')! == Bar.b
+	assert json.decode[BarAlias]('"c"')! == Bar.c
+}
+
+fn test_string_decode_fails() {
+	if _ := json.decode[Bar]('"d"') {
+		assert false
+	} else {
+		if err is json.JsonDecodeError {
+			assert err.line == 1
+			assert err.character == 1
+			assert err.message == 'Data: String value: `d` does not match any field in enum: &Bar'
+		}
+	}
+
+	if _ := json.decode[BarAlias]('"d"') {
+		assert false
+	} else {
+		if err is json.JsonDecodeError {
+			assert err.line == 1
+			assert err.character == 1
+			assert err.message == 'Data: String value: `d` does not match any field in enum: &BarAlias'
+		}
+	}
+}
+
+fn test_invalid_decode_fails() {
+	if _ := json.decode[Bar]('true') {
+		assert false
+	} else {
+		if err is json.JsonDecodeError {
+			assert err.line == 1
+			assert err.character == 1
+			assert err.message == 'Data: Expected number or string value for enum, got: boolean'
+		}
+	}
+
+	if _ := json.decode[BarAlias]('true') {
+		assert false
+	} else {
+		if err is json.JsonDecodeError {
+			assert err.line == 1
+			assert err.character == 1
+			assert err.message == 'Data: Expected number or string value for enum, got: boolean'
+		}
+	}
+}
diff --git a/vlib/x/json2/decoder2/tests/decode_escaped_string_test.v b/vlib/x/json2/decoder2/tests/decode_escaped_string_test.v
index d3e437895a..59a65a8e94 100644
--- a/vlib/x/json2/decoder2/tests/decode_escaped_string_test.v
+++ b/vlib/x/json2/decoder2/tests/decode_escaped_string_test.v
@@ -3,7 +3,7 @@ import x.json2.decoder2
 
 fn test_decode_escaped_string() {
 	escaped_strings := ['test', 'test\\sd', 'test\nsd', '\ntest', 'test\\"', 'test\\', 'test\u1234ps',
-		'test\u1234', '\u1234\\\t"', '']
+		'test\u1234', '\u1234\\\t"', '', '\uff0f', 'test \uff0f test', '😀', 'text 😀 text']
 
 	json_string := json2.encode[[]string](escaped_strings)
 	decoded_strings := decoder2.decode[[]string](json_string)!