sep_comp: improve deadness management in compile_class_to_c

Signed-off-by: Jean Privat <jean@pryen.org>

diff --git a/src/compiler/separate_compiler.nit b/src/compiler/separate_compiler.nit
index b1e08c8..44bb68f 100644 (file)
--- a/src/compiler/separate_compiler.nit
+++ b/src/compiler/separate_compiler.nit
@@ -819,12 +819,15 @@ class SeparateCompiler
                var v = new_visitor
 
                var rta = runtime_type_analysis
-               var is_dead = rta != null and not rta.live_classes.has(mclass) and not mtype.is_c_primitive and mclass.name != "NativeArray" and mclass.name != "Pointer"
+               var is_dead = rta != null and not rta.live_classes.has(mclass)
+               # While the class may be dead, some part of separately compiled code may use symbols associated to the class, so
+               # in order to compile and link correctly the C code, these symbols should be declared and defined.
+               var need_corpse = is_dead and mtype.is_c_primitive or mclass.kind == extern_kind or mclass.kind == enum_kind
 
-               v.add_decl("/* runtime class {c_name} */")
+               v.add_decl("/* runtime class {c_name}: {mclass.full_name} (dead={is_dead}; need_corpse={need_corpse})*/")
 
                # Build class vft
-               if not is_dead then
+               if not is_dead or need_corpse then
                        self.provide_declaration("class_{c_name}", "extern const struct class class_{c_name};")
                        v.add_decl("const struct class class_{c_name} = \{")
                        v.add_decl("{self.box_kind_of(mclass)}, /* box_kind */")
@@ -861,7 +864,8 @@ class SeparateCompiler
                        self.header.add_decl("{mtype.ctype_extern} value;")
                        self.header.add_decl("\};")
 
-                       if not rta.live_types.has(mtype) and mtype.mclass.name != "Pointer" then return
+                       # Pointer is needed by extern types, live or not
+                       if is_dead and mtype.mclass.name != "Pointer" then return
 
                        #Build BOX
                        self.provide_declaration("BOX_{c_name}", "val* BOX_{c_name}({mtype.ctype_extern});")
@@ -877,6 +881,7 @@ class SeparateCompiler
                        v.add("return (val*)res;")
                        v.add("\}")
 
+                       # A Pointer class also need its constructor
                        if mtype.mclass.name != "Pointer" then return
 
                        v = new_visitor
@@ -931,7 +936,7 @@ class SeparateCompiler
                        var pointer_type = mainmodule.pointer_type
 
                        self.provide_declaration("NEW_{c_name}", "{mtype.ctype} NEW_{c_name}(const struct type* type);")
-                       v.add_decl("/* allocate {mtype} */")
+                       v.add_decl("/* allocate extern {mtype} */")
                        v.add_decl("{mtype.ctype} NEW_{c_name}(const struct type* type) \{")
                        if is_dead then
                                v.add_abort("{mclass} is DEAD")