From 9fbea31f476e40908f12279c5e6ff741e7d54bcf Mon Sep 17 00:00:00 2001
From: Alexander Medvednikov <alexander@vlang.io>
Date: Sun, 6 Sep 2020 13:02:29 +0200
Subject: [PATCH] autofree: fix exprs N levels deep

---
 vlib/v/ast/ast.v                             |  2 +-
 vlib/v/gen/cgen.v                            | 15 +++++++++------
 vlib/v/gen/fn.v                              |  7 ++++---
 vlib/v/gen/str.v                             |  6 ++++--
 vlib/v/tests/valgrind/1.strings_and_arrays.v |  2 +-
 5 files changed, 19 insertions(+), 13 deletions(-)

diff --git a/vlib/v/ast/ast.v b/vlib/v/ast/ast.v
index 4c7310dd65..ddc3340046 100644
--- a/vlib/v/ast/ast.v
+++ b/vlib/v/ast/ast.v
@@ -307,7 +307,7 @@ pub:
 	comments        []Comment
 pub mut:
 	typ             table.Type
-	is_tmp_autofree bool // for autofree
+	is_tmp_autofree bool
 	// tmp_name        string // for autofree
 }
 
diff --git a/vlib/v/gen/cgen.v b/vlib/v/gen/cgen.v
index edcfb3f989..8c520e4b99 100644
--- a/vlib/v/gen/cgen.v
+++ b/vlib/v/gen/cgen.v
@@ -99,7 +99,7 @@ mut:
 	sql_side              SqlExprSide // left or right, to distinguish idents in `name == name`
 	inside_vweb_tmpl      bool
 	inside_return         bool
-	strs_to_free          string
+	strs_to_free          []string // strings.Builder
 	inside_call           bool
 	has_main              bool
 	inside_const          bool
@@ -725,18 +725,21 @@ fn (mut g Gen) write_v_source_line_info(pos token.Position) {
 
 fn (mut g Gen) stmt(node ast.Stmt) {
 	g.stmt_path_pos << g.out.len
-	/*
 	defer {
 		// If we have temporary string exprs to free after this statement, do it. e.g.:
 		// `foo('a' + 'b')` => `tmp := 'a' + 'b'; foo(tmp); string_free(&tmp);`
 		if g.pref.autofree {
-			if g.strs_to_free != '' {
-				g.writeln(g.strs_to_free)
-				g.strs_to_free = ''
+			if g.strs_to_free.len != 0 {
+				g.writeln('// strs_to_free:')
+				for s in g.strs_to_free {
+					g.writeln(s)
+				}
+				g.strs_to_free = []
+				// s := g.strs_to_free.str()
+				// g.strs_to_free.free()
 			}
 		}
 	}
-	*/
 	// println('cgen.stmt()')
 	// g.writeln('//// stmt start')
 	match node {
diff --git a/vlib/v/gen/fn.v b/vlib/v/gen/fn.v
index 3a2414b318..22bc7ccca0 100644
--- a/vlib/v/gen/fn.v
+++ b/vlib/v/gen/fn.v
@@ -632,15 +632,16 @@ fn (mut g Gen) fn_call(node ast.CallExpr) {
 		// g.write(cur_line + ' /* cur line*/')
 		// g.write(tmp)
 		// Now free the tmp arg vars right after the function call
-		g.writeln(';')
+		g.strs_to_free << (';')
 		for i, arg in node.args {
 			if arg.is_tmp_autofree {
 				fn_name := node.name.replace('.', '_')
 				tmp := '_tt${g.tmp_count2}_arg_expr_${fn_name}_$i'
-				g.writeln('string_free(&$tmp);')
+				g.strs_to_free << ('string_free(&$tmp);')
+				// g.writeln('string_free(&$tmp);')
 			}
 		}
-		g.writeln('')
+		// g.writeln('')
 	}
 }
 
diff --git a/vlib/v/gen/str.v b/vlib/v/gen/str.v
index deb5251648..6e77870727 100644
--- a/vlib/v/gen/str.v
+++ b/vlib/v/gen/str.v
@@ -194,11 +194,12 @@ fn (mut g Gen) string_inter_literal_sb_optimized(call_expr ast.CallExpr) {
 fn (mut g Gen) string_inter_literal(node ast.StringInterLiteral) {
 	mut cur_line := ''
 	mut tmp := ''
-	free := !g.pref.experimental && g.pref.autofree && g.inside_call && !g.inside_return &&
+	free := false && !g.pref.experimental && g.pref.autofree && g.inside_call && !g.inside_return &&
 		g.inside_ternary == 0 && !g.inside_const
 	// && g.cur_fn != 0 &&
 	// g.cur_fn.name != ''
-	if free {
+	/*
+	if false && free {
 		// Save the string expr in a temporary variable, so that it can be removed after the call.
 		tmp = g.new_tmp_var()
 		/*
@@ -214,6 +215,7 @@ fn (mut g Gen) string_inter_literal(node ast.StringInterLiteral) {
 		g.write('string $tmp = ')
 		g.strs_to_free += 'string_free(&$tmp); /*tmp str*/'
 	}
+	*/
 	g.write('_STR("')
 	// Build the string with %
 	mut end_string := false
diff --git a/vlib/v/tests/valgrind/1.strings_and_arrays.v b/vlib/v/tests/valgrind/1.strings_and_arrays.v
index d255fd0b45..f2b03716c7 100644
--- a/vlib/v/tests/valgrind/1.strings_and_arrays.v
+++ b/vlib/v/tests/valgrind/1.strings_and_arrays.v
@@ -25,7 +25,7 @@ fn handle_int(n int) {
 fn str_tmp_expr() {
 	println('a' + 'b') // tmp expression result must be freed
 	handle_strings('c' + 'd', 'e' + 'f') // multiple tmp expressions must be freed
-	// handle_int(handle_strings('x' + 'y', 'f')) // exprs 2 levels deep must bee freed
+	handle_int(handle_strings('x' + 'y', 'f')) // exprs 2 levels deep must bee freed
 }
 
 struct Foo {