From 60fbceea43263497ad484efdad620b22a1cf78d1 Mon Sep 17 00:00:00 2001
From: Alexander Medvednikov <alexander@medvednikov.com>
Date: Wed, 25 Mar 2020 12:26:54 +0300
Subject: [PATCH] memory: free_scope_vars()

---
 vlib/compiler/aparser.v               |  2 +-
 vlib/v/gen/cgen.v                     | 33 ++++++++++++++++++++-------
 vlib/v/tests/valgrind/1.vv            | 10 ++++++--
 vlib/v/tests/valgrind/valgrind_test.v |  3 ++-
 4 files changed, 36 insertions(+), 12 deletions(-)

diff --git a/vlib/compiler/aparser.v b/vlib/compiler/aparser.v
index 56eec65f2b..4dd6428210 100644
--- a/vlib/compiler/aparser.v
+++ b/vlib/compiler/aparser.v
@@ -451,7 +451,7 @@ fn (p mut Parser) parse(pass Pass) {
 	}
 	p.fgen_nl()
 	p.builtin_mod = p.mod == 'builtin'
-	p.can_chash = p.mod in ['parser', 'gg2', 'ui', 'uiold', 'darwin', 'clipboard', 'webview'] // TODO tmp remove
+	p.can_chash = p.mod in ['parser', 'gg2', 'ui', 'uiold', 'darwin', 'clipboard', 'webview', 'gen'] // TODO tmp remove
 	// Import pass - the first and the smallest pass that only analyzes imports
 	// if we are a building module get the full module name from v.mod
 	fq_mod := if p.pref.build_mode == .build_module && p.v.pref.mod.ends_with(p.mod) { p.v.pref.mod }
diff --git a/vlib/v/gen/cgen.v b/vlib/v/gen/cgen.v
index 7d2e0a53da..e456aba354 100644
--- a/vlib/v/gen/cgen.v
+++ b/vlib/v/gen/cgen.v
@@ -662,14 +662,7 @@ fn (g mut Gen) gen_fn_decl(it ast.FnDecl) {
 	g.stmts(it.stmts)
 	// ////////////
 	if g.autofree {
-		scope := g.file.scope.innermost(it.pos.pos - 1)
-		for _, var in scope.vars {
-			sym := g.table.get_type_symbol(var.typ)
-			if sym.kind == .array && !table.type_is_optional(var.typ) {
-				g.writeln('array_free($var.name); // autofree')
-			}
-			// println(var.name)
-		}
+		g.free_scope_vars(it.pos.pos - 1)
 	}
 	// /////////
 	if is_main {
@@ -685,6 +678,30 @@ fn (g mut Gen) gen_fn_decl(it ast.FnDecl) {
 	g.fn_decl = 0
 }
 
+fn (g mut Gen) free_scope_vars(pos int) {
+	scope := g.file.scope.innermost(pos)
+	for _, var in scope.vars {
+		sym := g.table.get_type_symbol(var.typ)
+		if sym.kind == .array && !table.type_is_optional(var.typ) {
+			g.writeln('array_free($var.name); // autofreed')
+		}
+		if sym.kind == .string && !table.type_is_optional(var.typ) {
+			// Don't free simple string literals.
+			t := typeof(var.expr)
+			match var.expr {
+				ast.StringLiteral {
+					g.writeln('// str literal')
+					continue
+				}
+				else {
+					g.writeln('// other' + t)
+				}
+	}
+			g.writeln('string_free($var.name); // autofreed')
+		}
+	}
+}
+
 fn (g mut Gen) fn_args(args []table.Arg, is_variadic bool) {
 	no_names := args.len > 0 && args[0].name == 'arg_1'
 	for i, arg in args {
diff --git a/vlib/v/tests/valgrind/1.vv b/vlib/v/tests/valgrind/1.vv
index c4e73b9a14..7b1f596d8f 100644
--- a/vlib/v/tests/valgrind/1.vv
+++ b/vlib/v/tests/valgrind/1.vv
@@ -7,10 +7,16 @@ fn return_array(array_arg []string) []int { // array argument must not be freed
 
 fn foo() {
 	nums := [1, 2, 3] // local array must be freed
-	nums_copy := nums // array assignments call .clone()
 	println(nums)
+
+	nums_copy := nums // array assignments call .clone()
 	println(nums_copy)
-	// nums.free() // this should result in a double free and a CI error
+
+	name  := 'Peter' // string literals mustn't be freed
+	str_inter := 'hello, $name' // concatenated strings must be freed
+
+
+	//nums.free() // this should result in a double free and a CI error
 }
 
 fn main() {
diff --git a/vlib/v/tests/valgrind/valgrind_test.v b/vlib/v/tests/valgrind/valgrind_test.v
index 6bbf5ac4dc..8777907bb6 100644
--- a/vlib/v/tests/valgrind/valgrind_test.v
+++ b/vlib/v/tests/valgrind/valgrind_test.v
@@ -31,8 +31,9 @@ fn test_all() {
 	for test in tests {
 		bench.step()
 		full_test_path := os.real_path(test)
+		println('x.v: $wrkdir/x.v')
 		os.system('cp ${dir}/${test} $wrkdir/x.v') // cant run .vv file
-		res := os.exec('$vexe -b v2 $wrkdir/x.v') or {
+		res := os.exec('$vexe -verbose=3 -b v2 -csource keep -cg $wrkdir/x.v') or {
 			bench.fail()
 			eprintln(bench.step_message_fail('valgrind $test failed'))
 			continue