cgen: fix dump(c_struct), where c_struct has fields of type &&char

Author: spytheman

vlib/v/gen/c/auto_str_methods.v

@@ -773,6 +773,10 @@ fn (g &Gen) type_to_fmt(typ ast.Type) StrIntpType {
 		// return '%C\\000' // a C string
 		return .si_s
 	}
+	typ_nr_muls := typ.nr_muls()
+	if typ_nr_muls > 1 {
+		return .si_p
+	}
 	sym := g.table.sym(typ)
 	if typ.is_ptr() && (typ.is_int_valptr() || typ.is_float_valptr()) {
 		return .si_s
@@ -902,7 +906,7 @@ fn (mut g Gen) gen_str_for_struct(info ast.Struct, styp string, str_fn_name stri
 			g.get_str_fn(ftyp_noshared)
 		}
 
-		// manage the fact hat with float we use always the g representation
+		// with floats we use always the g representation:
 		if sym.kind !in [.f32, .f64] {
 			fn_body.write_string('{_SLIT("$quote_str"), ${int(base_fmt)}, {.${data_str(base_fmt)}=')
 		} else {
@@ -913,7 +917,8 @@ fn (mut g Gen) gen_str_for_struct(info ast.Struct, styp string, str_fn_name stri
 		mut funcprefix := ''
 		mut func, mut caller_should_free := struct_auto_str_func(sym, field.typ, field_styp_fn_name,
 			field.name, sym_has_str_method, str_method_expects_ptr)
-		if field.typ in ast.cptr_types {
+		ftyp_nr_muls := field.typ.nr_muls()
+		if ftyp_nr_muls > 1 || field.typ in ast.cptr_types {
 			func = '(voidptr) it.$field.name'
 			caller_should_free = false
 		} else if ftyp_noshared.is_ptr() {

vlib/v/tests/dump_c_structs/dump_c_struct_test.v

@@ -1,4 +1,5 @@
 #include "@VMODROOT/epoll.h"
+#include "@VMODROOT/netdb.h"
 
 pub struct C.epoll_event {
 mut:
@@ -19,6 +20,14 @@ struct Epoll {
 	ev C.epoll_event
 }
 
+struct C.hostent {
+	h_name      &char
+	h_aliases   &&char
+	h_addrtype  int
+	h_length    int
+	h_addr_list &&char
+}
+
 fn test_dump_c_struct() {
 	ev := C.epoll_event{}
 	unsafe { C.memset(&ev, 0, sizeof(ev)) }
@@ -30,5 +39,12 @@ fn test_dump_c_struct() {
 	}
 	dump(e)
 	println(e)
+	//
+	mut hostent := &C.hostent{
+		h_addr_list: unsafe { nil }
+		h_aliases: unsafe { nil }
+		h_name: unsafe { nil }
+	}
+	dump(hostent)
 	assert true
 }

vlib/v/tests/dump_c_structs/netdb.h

@@ -0,0 +1,9 @@
+
+/* Description of data base entry for a single host.  */
+struct hostent {
+     char *h_name;         /* Official name of host.  */
+     char **h_aliases;     /* Alias list.  */
+     int h_addrtype;       /* Host address type.  */
+     int h_length;         /* Length of address.  */
+     char **h_addr_list;       /* List of addresses from name server.  */
+};