Add support for N_Block_Statement node

gnat2goto/driver/tree_walk.adb

@@ -146,6 +146,10 @@ package body Tree_Walk is
    with Pre  => Nkind (N) = N_Loop_Statement,
         Post => Kind (Do_Loop_Statement'Result) in Class_Code;
 
+   function Do_N_Block_Statement (N : Node_Id) return Irep
+   with Pre  => Nkind (N) = N_Block_Statement,
+        Post => Kind (Do_N_Block_Statement'Result) = I_Code_Block;
+
    procedure Do_Object_Declaration (N : Node_Id; Block : Irep)
    with Pre => Nkind (N) = N_Object_Declaration
                  and then Kind (Block) = I_Code_Block;
@@ -1949,6 +1953,15 @@ package body Tree_Walk is
       return Loop_Wrapper;
    end Do_Loop_Statement;
 
+   -----------------------------------------
+   --  Do_N_Block_Statement (nested declares)
+   -----------------------------------------
+
+   function Do_N_Block_Statement (N : Node_Id) return Irep is
+   begin
+      return Do_Subprogram_Or_Block (N);
+   end Do_N_Block_Statement;
+
    ---------------
    -- Do_Pragma --
    ---------------
@@ -4024,7 +4037,7 @@ package body Tree_Walk is
             Append_Op (Block, Do_Loop_Statement (N));
 
          when N_Block_Statement =>
-            Warn_Unhandled_Construct (Statement, "block");
+            Append_Op (Block, Do_N_Block_Statement (N));
 
          when N_Handled_Sequence_Of_Statements =>  -- this seems incorrct
             --  It should be block_statement

testsuite/gnat2goto/tests/statement_new_block_N_Block_Statement/statement_block.adb

@@ -0,0 +1,47 @@
+function Statement_Block return Integer is
+   Var1 : Integer :=1;
+   Var2 : Integer;
+
+   function Sum_Plus_Three(Left, Right : Integer) return Integer is
+      Local1 : Integer;
+   begin
+      declare
+         Local2 : Integer := 1;
+      begin
+         Local1 := Local2 + Var1 + 1;
+         Pragma Assert (Local1=3);
+      end;
+   return (Left + Right + Local1);
+   end Sum_Plus_Three;
+
+begin
+   ----------------------------------------
+   --  the below nested function call works, but is out of scope
+   --  and nested functions are not yet fully supported / tested
+   ----------------------------------------
+   --  Var1 := Sum_Plus_Three(3,4);
+   --  pragma Assert (Var1=10);
+   ----------------------------------------
+
+   declare
+      Var3 : Integer :=2;
+   begin
+      Var2 := Var3;
+      pragma Assert (Var2=2);
+      declare
+         Var4 : Integer := Var3;
+      begin
+         Var2 := Var4 + Var2;
+         Pragma Assert (Var2=4);
+      end;
+   end;
+
+   declare
+      Var5 : Integer := 6;
+   begin
+      Var2 := Var5 + Var2;
+   end;
+
+   pragma Assert (Var2=10);
+   return Var2;
+end Statement_Block;

testsuite/gnat2goto/tests/statement_new_block_N_Block_Statement/test.out

@@ -0,0 +1,5 @@
+[4] file statement_block.adb line 12 assertion: SUCCESS
+[1] file statement_block.adb line 30 assertion: SUCCESS
+[2] file statement_block.adb line 35 assertion: SUCCESS
+[3] file statement_block.adb line 45 assertion: SUCCESS
+VERIFICATION SUCCESSFUL