compile: casts ('isa' and 'as') with nullable info

Migration remark: considers that non-null objects can still contains null at runtime.

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

diff --git a/src/compiling/compiling_methods.nit b/src/compiling/compiling_methods.nit
index 935b3d0..ebbe750 100644 (file)
--- a/src/compiling/compiling_methods.nit
+++ b/src/compiling/compiling_methods.nit
@@ -615,19 +615,41 @@ end
 redef class MMType
        # Compile a subtype check to self
        # Return a NIT Bool
-       meth compile_cast(v: CompilerVisitor, recv: String): String
+       meth compile_cast(v: CompilerVisitor, recv: String, fromtype: MMType): String
        do
                # Fixme: handle formaltypes
                var g = local_class.global
-               return "TAG_Bool(({recv}==NIT_NULL) || VAL_ISA({recv}, {g.color_id}, {g.id_id})) /*cast {self}*/"
+               var s = ""
+               if fromtype.is_nullable then
+                       if self.is_nullable then
+                               s = "({recv}==NIT_NULL) || "
+                       else
+                               s = "({recv}!=NIT_NULL) && "
+                       end
+               else
+                       # FIXME This is used to not break code without the nullable KW
+                       s = "({recv}==NIT_NULL) || "
+               end
+               return "TAG_Bool({s}VAL_ISA({recv}, {g.color_id}, {g.id_id})) /*cast {self}*/"
        end
 
        # Compile a cast assertion
-       meth compile_type_check(v: CompilerVisitor, recv: String, n: PNode)
+       meth compile_type_check(v: CompilerVisitor, recv: String, n: PNode, fromtype: MMType)
        do
                # Fixme: handle formaltypes
                var g = local_class.global
-               v.add_instr("if (({recv}!=NIT_NULL) && !VAL_ISA({recv}, {g.color_id}, {g.id_id})) \{ fprintf(stderr, \"Cast failled\"); {v.printf_locate_error(n)} nit_exit(1); } /*cast {self}*/;")
+               var s = ""
+               if fromtype.is_nullable then
+                       if self.is_nullable then
+                               s = "({recv}!=NIT_NULL) && "
+                       else
+                               s = "({recv}==NIT_NULL) || "
+                       end
+               else
+                       # FIXME This is used to not break code without the nullable KW
+                       s = "({recv}!=NIT_NULL) && "
+               end
+               v.add_instr("if ({s}!VAL_ISA({recv}, {g.color_id}, {g.id_id})) \{ fprintf(stderr, \"Cast failled\"); {v.printf_locate_error(n)} nit_exit(1); } /*cast {self}*/;")
        end
 
        # Compile a notnull cast assertion
@@ -661,7 +683,7 @@ redef class ASignature
                                # FIXME: do not test always
                                # FIXME: handle formal types
                                v.add_instr("/* check if p<{ap.variable.stype} with p:{orig_type} */")
-                               ap.variable.stype.compile_type_check(v, params[ap.position], ap)
+                               ap.variable.stype.compile_type_check(v, params[ap.position], ap, orig_type)
                        end
                        v.add_assignment(cname, params[ap.position])
                end
@@ -1225,7 +1247,7 @@ redef class AIsaExpr
        redef meth compile_expr(v)
        do
                var e = v.compile_expr(n_expr)
-               return n_type.stype.compile_cast(v, e)
+               return n_type.stype.compile_cast(v, e, n_expr.stype)
        end
 end
 
@@ -1233,7 +1255,7 @@ redef class AAsCastExpr
        redef meth compile_expr(v)
        do
                var e = v.compile_expr(n_expr)
-               n_type.stype.compile_type_check(v, e, self)
+               n_type.stype.compile_type_check(v, e, self, n_expr.stype)
                return e
        end
 end