mcode: add new_default_value.

6 files changed, 27 insertions, 2 deletions

diff --git a/src/ortho/mcode/ortho_code-consts.adb b/src/ortho/mcode/ortho_code-consts.adb
index 4522e674a..7cc554211 100644
--- a/src/ortho/mcode/ortho_code-consts.adb
+++ b/src/ortho/mcode/ortho_code-consts.adb
@@ -219,6 +219,13 @@ package body Ortho_Code.Consts is
       return Cnodes.Last;
    end New_Null_Access;
 
+   function New_Default_Value (Ltype : O_Tnode) return O_Cnode is
+   begin
+      Cnodes.Append (Cnode_Common'(Kind => OC_Zero,
+                                   Lit_Type => Ltype));
+      return Cnodes.Last;
+   end New_Default_Value;
+
    function To_Cnode_Common is new Ada.Unchecked_Conversion
      (Source => Cnode_Addr, Target => Cnode_Common);
 
@@ -525,7 +532,8 @@ package body Ortho_Code.Consts is
            | OC_Sizeof
            | OC_Alignof
            | OC_Address
-           | OC_Subprg_Address =>
+           | OC_Subprg_Address
+           | OC_Zero =>
             raise Syntax_Error;
       end case;
    end Get_Const_Bytes;
diff --git a/src/ortho/mcode/ortho_code-consts.ads b/src/ortho/mcode/ortho_code-consts.ads
index 102dc59d3..0a4f347fc 100644
--- a/src/ortho/mcode/ortho_code-consts.ads
+++ b/src/ortho/mcode/ortho_code-consts.ads
@@ -19,6 +19,7 @@ with Interfaces; use Interfaces;
 
 package Ortho_Code.Consts is
    type OC_Kind is (OC_Signed, OC_Unsigned, OC_Float, OC_Lit, OC_Null,
+                    OC_Zero,
                     OC_Array, OC_Record, OC_Union,
                     OC_Subprg_Address, OC_Address,
                     OC_Sizeof, OC_Alignof);
@@ -78,6 +79,7 @@ package Ortho_Code.Consts is
    function New_Null_Access (Ltype : O_Tnode) return O_Cnode;
    function New_Global_Unchecked_Address (Decl : O_Dnode; Atype : O_Tnode)
                                          return O_Cnode;
+   function New_Default_Value (Ltype : O_Tnode) return O_Cnode;
    function New_Global_Address (Decl : O_Dnode; Atype : O_Tnode)
                                return O_Cnode;
    function New_Subprogram_Address (Subprg : O_Dnode; Atype : O_Tnode)
diff --git a/src/ortho/mcode/ortho_code-exprs.adb b/src/ortho/mcode/ortho_code-exprs.adb
index 47064e76e..4e0d6bdc4 100644
--- a/src/ortho/mcode/ortho_code-exprs.adb
+++ b/src/ortho/mcode/ortho_code-exprs.adb
@@ -721,7 +721,8 @@ package body Ortho_Code.Exprs is
               | OC_Record
               | OC_Union
               | OC_Sizeof
-              | OC_Alignof =>
+              | OC_Alignof
+              | OC_Zero =>
                raise Syntax_Error;
          end case;
       end if;
diff --git a/src/ortho/mcode/ortho_code-x86-emits.adb b/src/ortho/mcode/ortho_code-x86-emits.adb
index 48590af97..9e73b2dab 100644
--- a/src/ortho/mcode/ortho_code-x86-emits.adb
+++ b/src/ortho/mcode/ortho_code-x86-emits.adb
@@ -3183,6 +3183,10 @@ package body Ortho_Code.X86.Emits is
                   Emit_Const (E);
                end loop;
             end;
+         when OC_Zero =>
+            for I in 1 .. Get_Type_Size (Get_Const_Type (Val)) loop
+               Gen_8 (0);
+            end loop;
          when OC_Sizeof
            | OC_Alignof
            | OC_Union =>
diff --git a/src/ortho/mcode/ortho_mcode.adb b/src/ortho/mcode/ortho_mcode.adb
index cb2ab6663..fac45e438 100644
--- a/src/ortho/mcode/ortho_mcode.adb
+++ b/src/ortho/mcode/ortho_mcode.adb
@@ -253,6 +253,12 @@ package body Ortho_Mcode is
         (Ortho_Code.Consts.New_Null_Access (Ortho_Code.O_Tnode (Ltype)));
    end New_Null_Access;
 
+   function New_Default_Value (Ltype : O_Tnode) return O_Cnode is
+   begin
+      return O_Cnode
+        (Ortho_Code.Consts.New_Default_Value (Ortho_Code.O_Tnode (Ltype)));
+   end New_Default_Value;
+
    procedure Start_Record_Aggr (List : out O_Record_Aggr_List;
                                 Atype : O_Tnode) is
    begin
diff --git a/src/ortho/mcode/ortho_mcode.ads b/src/ortho/mcode/ortho_mcode.ads
index ec65fab5c..dda220f1c 100644
--- a/src/ortho/mcode/ortho_mcode.ads
+++ b/src/ortho/mcode/ortho_mcode.ads
@@ -145,6 +145,10 @@ package Ortho_Mcode is
    --  Create a null access literal.
    function New_Null_Access (Ltype : O_Tnode) return O_Cnode;
 
+   --  Create a literal with default (null) values.  Can only be used to
+   --  define the initial value of a static decalaration.
+   function New_Default_Value (Ltype : O_Tnode) return O_Cnode;
+
    --  Build a record/array aggregate.
    --  The aggregate is constant, and therefore can be only used to initialize
    --  constant declaration.