From 46a5c487c17ad87d1937e998b79a8666d5963956 Mon Sep 17 00:00:00 2001
From: Delyan Angelov <delian66@gmail.com>
Date: Fri, 8 Jan 2021 17:24:42 +0200
Subject: [PATCH] parser,fmt: implement `[manualfree] module abc` for opting
 out *all* fns in a given .v from autofree

---
 CHANGELOG.md                       |  2 +-
 vlib/v/ast/ast.v                   |  1 +
 vlib/v/fmt/fmt.v                   |  1 +
 vlib/v/fmt/tests/manualfree_keep.v | 18 ++++++++++++++++++
 vlib/v/parser/fn.v                 |  2 +-
 vlib/v/parser/parser.v             | 24 ++++++++++++++++++++++++
 vlib/v/table/attr.v                |  3 +++
 7 files changed, 49 insertions(+), 2 deletions(-)
 create mode 100644 vlib/v/fmt/tests/manualfree_keep.v

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 39540f10ee..d0681ce19d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,7 +7,7 @@
 - `byte.str()` has been fixed and works like with all other numbers. `byte.ascii_str()` has been added.
 - Smart cast in for loops: `for mut x is string {}`.
 - `[noinit]` struct attribute to disallow direct struct initialization with `Foo{}`.
-- `[manualfree]` attribute for functions, that want to do their own memory management.
+- support `[manualfree] fn f1(){}` and `[manualfree] module m1`, for functions doing their own memory management.
 
 ## V 0.2.1
 *30 Dec 2020*
diff --git a/vlib/v/ast/ast.v b/vlib/v/ast/ast.v
index 0309d64615..f1e073b59d 100644
--- a/vlib/v/ast/ast.v
+++ b/vlib/v/ast/ast.v
@@ -131,6 +131,7 @@ pub fn (e &SelectorExpr) root_ident() Ident {
 pub struct Module {
 pub:
 	name       string
+	attrs      []table.Attr
 	pos        token.Position
 	is_skipped bool // module main can be skipped in single file programs
 }
diff --git a/vlib/v/fmt/fmt.v b/vlib/v/fmt/fmt.v
index 85364bdae8..617f843db4 100644
--- a/vlib/v/fmt/fmt.v
+++ b/vlib/v/fmt/fmt.v
@@ -193,6 +193,7 @@ pub fn (mut f Fmt) mod(mod ast.Module) {
 	if mod.is_skipped {
 		return
 	}
+	f.attrs(mod.attrs)
 	f.writeln('module $mod.name\n')
 }
 
diff --git a/vlib/v/fmt/tests/manualfree_keep.v b/vlib/v/fmt/tests/manualfree_keep.v
new file mode 100644
index 0000000000..98de3f1d0d
--- /dev/null
+++ b/vlib/v/fmt/tests/manualfree_keep.v
@@ -0,0 +1,18 @@
+[manualfree]
+module main
+
+fn abc() {
+	x := 'abc should be autofreed'
+	println(x)
+}
+
+[manualfree]
+fn xyz() {
+	x := 'xyz should do its own memory management'
+	println(x)
+}
+
+fn main() {
+	abc()
+	xyz()
+}
diff --git a/vlib/v/parser/fn.v b/vlib/v/parser/fn.v
index 738aa9a65e..20e9bbe543 100644
--- a/vlib/v/parser/fn.v
+++ b/vlib/v/parser/fn.v
@@ -156,7 +156,7 @@ pub fn (mut p Parser) call_args() []ast.CallArg {
 fn (mut p Parser) fn_decl() ast.FnDecl {
 	p.top_level_statement_start()
 	start_pos := p.tok.position()
-	is_manualfree := p.attrs.contains('manualfree')
+	is_manualfree := p.is_manualfree || p.attrs.contains('manualfree')
 	is_deprecated := p.attrs.contains('deprecated')
 	is_direct_arr := p.attrs.contains('direct_array_access')
 	mut is_unsafe := p.attrs.contains('unsafe')
diff --git a/vlib/v/parser/parser.v b/vlib/v/parser/parser.v
index d1cfd5e352..575a0c52a9 100644
--- a/vlib/v/parser/parser.v
+++ b/vlib/v/parser/parser.v
@@ -45,6 +45,7 @@ mut:
 	or_is_handled     bool         // ignore `or` in this expression
 	builtin_mod       bool         // are we in the `builtin` module?
 	mod               string       // current module name
+	is_manualfree     bool         // true when `[manualfree] module abc`, makes *all* fns in the current .v file, opt out of autofree
 	attrs             []table.Attr // attributes before next decl stmt
 	expr_mod          string       // for constructing full type names in parse_type()
 	scope             &ast.Scope
@@ -817,10 +818,12 @@ fn (mut p Parser) attributes() {
 }
 
 fn (mut p Parser) parse_attr() table.Attr {
+	apos := p.prev_tok.position()
 	if p.tok.kind == .key_unsafe {
 		p.next()
 		return table.Attr{
 			name: 'unsafe'
+			pos: apos.extend(p.tok.position())
 		}
 	}
 	mut is_ctdefine := false
@@ -862,6 +865,7 @@ fn (mut p Parser) parse_attr() table.Attr {
 		is_ctdefine: is_ctdefine
 		arg: arg
 		is_string_arg: is_string_arg
+		pos: apos.extend(p.tok.position())
 	}
 }
 
@@ -1670,10 +1674,16 @@ fn (mut p Parser) parse_number_literal() ast.Expr {
 }
 
 fn (mut p Parser) module_decl() ast.Module {
+	mut module_attrs := []table.Attr{}
+	if p.tok.kind == .lsbr {
+		p.attributes()
+		module_attrs = p.attrs
+	}
 	mut name := 'main'
 	is_skipped := p.tok.kind != .key_module
 	mut module_pos := token.Position{}
 	if !is_skipped {
+		p.attrs = []
 		module_pos = p.tok.position()
 		p.next()
 		mut pos := p.tok.position()
@@ -1710,8 +1720,22 @@ fn (mut p Parser) module_decl() ast.Module {
 	}
 	p.mod = full_mod
 	p.builtin_mod = p.mod == 'builtin'
+	if !is_skipped {
+		for ma in module_attrs {
+			match ma.name {
+				'manualfree' {
+					p.is_manualfree = true
+				}
+				else {
+					p.error_with_pos('unknown module attribute `[$ma.name]`', ma.pos)
+					return ast.Module{}
+				}
+			}
+		}
+	}
 	return ast.Module{
 		name: full_mod
+		attrs: module_attrs
 		is_skipped: is_skipped
 		pos: module_pos
 	}
diff --git a/vlib/v/table/attr.v b/vlib/v/table/attr.v
index 91109e7007..8eb93a608e 100644
--- a/vlib/v/table/attr.v
+++ b/vlib/v/table/attr.v
@@ -3,6 +3,8 @@
 // that can be found in the LICENSE file.
 module table
 
+import v.token
+
 // e.g. `[unsafe]`
 pub struct Attr {
 pub:
@@ -11,6 +13,7 @@ pub:
 	is_ctdefine   bool   // [if name]
 	arg           string // [name: arg]
 	is_string_arg bool   // [name: 'arg']
+	pos           token.Position
 }
 
 // no square brackets