From ad41cd5c6f35dd236751e26b07a83a9af66660cd Mon Sep 17 00:00:00 2001
From: Delyan Angelov <delian66@gmail.com>
Date: Fri, 23 Jul 2021 10:50:50 +0300
Subject: [PATCH] cgen: fix `dump(fn_name)` (closes #10912)

---
 vlib/v/gen/c/dumpexpr.v      | 78 ++++++++++++++++++++----------------
 vlib/v/tests/dump_fns_test.v | 22 ++++++++++
 2 files changed, 65 insertions(+), 35 deletions(-)
 create mode 100644 vlib/v/tests/dump_fns_test.v

diff --git a/vlib/v/gen/c/dumpexpr.v b/vlib/v/gen/c/dumpexpr.v
index 9813739a8b..fcb6bbd750 100644
--- a/vlib/v/gen/c/dumpexpr.v
+++ b/vlib/v/gen/c/dumpexpr.v
@@ -1,6 +1,7 @@
 module c
 
 import v.ast
+import strings
 
 fn (mut g Gen) dump_expr(node ast.DumpExpr) {
 	sexpr := ctoslit(node.expr.str())
@@ -17,48 +18,55 @@ fn (mut g Gen) dump_expr(node ast.DumpExpr) {
 }
 
 fn (mut g Gen) dump_expr_definitions() {
-	if g.pref.build_mode == .build_module {
-		for dump_type, cname in g.table.dumps {
-			is_ptr := ast.Type(dump_type).is_ptr()
-			ptr_suffix := if is_ptr { '*' } else { '' }
-			dump_fn_name := '_v_dump_expr_$cname' + (if is_ptr { '_ptr' } else { '' })
-			g.writeln_fn_header('$cname$ptr_suffix ${dump_fn_name}(string fpath, int line, string sexpr, $cname$ptr_suffix x)')
+	mut dump_typedefs := map[string]bool{}
+	mut dump_fns := strings.new_builder(100)
+	for dump_type, cname in g.table.dumps {
+		to_string_fn_name := g.gen_str_for_type(dump_type)
+		is_ptr := ast.Type(dump_type).is_ptr()
+		ptr_asterisk := if is_ptr { '*' } else { '' }
+		dump_sym := g.table.get_type_symbol(dump_type)
+		mut str_dumparg_type := '$cname$ptr_asterisk'
+		if dump_sym.kind == .function {
+			fninfo := dump_sym.info as ast.FnType
+			str_dumparg_type = 'DumpFNType_$cname'
+			tdef_pos := g.out.len
+			g.write_fn_ptr_decl(&fninfo, str_dumparg_type)
+			str_tdef := g.out.after(tdef_pos)
+			g.out.go_back(str_tdef.len)
+			dump_typedefs['typedef $str_tdef;'] = true
 		}
-	} else {
-		for dump_type, cname in g.table.dumps {
-			to_string_fn_name := g.gen_str_for_type(dump_type)
-			is_ptr := ast.Type(dump_type).is_ptr()
-			ptr_astarisk := if is_ptr { '*' } else { '' }
-			dump_fn_name := '_v_dump_expr_$cname' + (if is_ptr { '_ptr' } else { '' })
-			if g.writeln_fn_header('$cname$ptr_astarisk ${dump_fn_name}(string fpath, int line, string sexpr, $cname$ptr_astarisk x)') {
-				continue
-			}
-			g.definitions.writeln('\teprint(${ctoslit('[')});')
-			g.definitions.writeln('\teprint(fpath);')
-			g.definitions.writeln('\teprint(${ctoslit(':')});')
-			g.definitions.writeln('\teprint(int_str(line));')
-			g.definitions.writeln('\teprint(${ctoslit('] ')});')
-
-			// g.definitions.writeln('\t/* dump_type: $dump_type | to_string_fn_name: $to_string_fn_name | is_ptr: $is_ptr | ptr_astarisk: $ptr_astarisk | dump_fn_name: $dump_fn_name | cname: $cname */')
-			g.definitions.writeln('\teprint(sexpr);')
-			g.definitions.writeln('\teprint(${ctoslit(': ')});')
-
-			if is_ptr {
-				g.definitions.writeln('\teprint(${ctoslit('&')});')
-			}
-			g.definitions.writeln('\teprintln(${to_string_fn_name}(${ptr_astarisk}x));')
-
-			g.definitions.writeln('\treturn x;')
-			g.definitions.writeln('}')
+		dump_fn_name := '_v_dump_expr_$cname' + (if is_ptr { '_ptr' } else { '' })
+		if g.writeln_fn_header('$str_dumparg_type ${dump_fn_name}(string fpath, int line, string sexpr, $str_dumparg_type x)', mut
+			dump_fns)
+		{
+			continue
 		}
+		dump_fns.writeln('\teprint(${ctoslit('[')});')
+		dump_fns.writeln('\teprint(fpath);')
+		dump_fns.writeln('\teprint(${ctoslit(':')});')
+		dump_fns.writeln('\teprint(int_str(line));')
+		dump_fns.writeln('\teprint(${ctoslit('] ')});')
+		// dump_fns.writeln('\t/* dump_type: $dump_type | to_string_fn_name: $to_string_fn_name | is_ptr: $is_ptr | ptr_asterisk: $ptr_asterisk | dump_fn_name: $dump_fn_name | cnam: $cname */')
+		dump_fns.writeln('\teprint(sexpr);')
+		dump_fns.writeln('\teprint(${ctoslit(': ')});')
+		if is_ptr {
+			dump_fns.writeln('\teprint(${ctoslit('&')});')
+		}
+		dump_fns.writeln('\teprintln(${to_string_fn_name}(${ptr_asterisk}x));')
+		dump_fns.writeln('\treturn x;')
+		dump_fns.writeln('}')
 	}
+	for tdef, _ in dump_typedefs {
+		g.definitions.writeln(tdef)
+	}
+	g.definitions.writeln(dump_fns.str())
 }
 
-fn (mut g Gen) writeln_fn_header(s string) bool {
+fn (mut g Gen) writeln_fn_header(s string, mut sb strings.Builder) bool {
 	if g.pref.build_mode == .build_module {
-		g.definitions.writeln('$s;')
+		sb.writeln('$s;')
 		return true
 	}
-	g.definitions.writeln('$s {')
+	sb.writeln('$s {')
 	return false
 }
diff --git a/vlib/v/tests/dump_fns_test.v b/vlib/v/tests/dump_fns_test.v
new file mode 100644
index 0000000000..c56b1eff58
--- /dev/null
+++ b/vlib/v/tests/dump_fns_test.v
@@ -0,0 +1,22 @@
+fn foo() int {
+	return 1
+}
+
+fn zoo() int {
+	return 123
+}
+
+fn test_dump_of_functions() {
+	x := dump(foo)
+	y := dump(zoo)
+	dump(foo())
+	dump(zoo())
+	dump(x)
+	dump(y)
+	dump(x())
+	dump(y())
+	assert voidptr(x) != 0
+	assert voidptr(y) != 0
+	assert foo == x
+	assert y == zoo
+}