Добавлена конструкция WHILE-DO

[dsw-obn.git] / src / oberon.c

diff --git a/src/oberon.c b/src/oberon.c
index f2c901433aeb49363ef01007ed8336a1e5db1919..8a84e1359dcd48f368f41cd945a76bb92a11b599 100644 (file)
--- a/src/oberon.c
+++ b/src/oberon.c
@@ -64,7 +64,10 @@ enum {
        STRING,
        IF,
        THEN,
-       ELSE
+       ELSE,
+       ELSIF,
+       WHILE,
+       DO
 };
 
 // =======================================================================
@@ -395,6 +398,18 @@ oberon_read_ident(oberon_context_t * ctx)
        {
                ctx -> token = ELSE;
        }
+       else if(strcmp(ident, "ELSIF") == 0)
+       {
+               ctx -> token = ELSIF;
+       }
+       else if(strcmp(ident, "WHILE") == 0)
+       {
+               ctx -> token = WHILE;
+       }
+       else if(strcmp(ident, "DO") == 0)
+       {
+               ctx -> token = DO;
+       }
 }
 
 static void
@@ -2918,8 +2933,25 @@ oberon_statement(oberon_context_t * ctx)
                oberon_generate_branch(ctx, cond, false, els);
                oberon_statement_seq(ctx);
                oberon_generate_goto(ctx, end);
-
                oberon_generate_label(ctx, els);
+
+               while(ctx -> token == ELSIF)
+               {
+                       els = oberon_generator_reserve_label(ctx);
+
+                       oberon_assert_token(ctx, ELSIF);
+                       cond = oberon_expr(ctx);
+                       if(cond -> result -> class != OBERON_TYPE_BOOLEAN)
+                       {
+                               oberon_error(ctx, "condition must be boolean");
+                       }
+                       oberon_assert_token(ctx, THEN);
+                       oberon_generate_branch(ctx, cond, false, els);
+                       oberon_statement_seq(ctx);
+                       oberon_generate_goto(ctx, end);
+                       oberon_generate_label(ctx, els);
+               }
+
                if(ctx -> token == ELSE)
                {
                        oberon_assert_token(ctx, ELSE);
@@ -2929,6 +2961,31 @@ oberon_statement(oberon_context_t * ctx)
                oberon_generate_label(ctx, end);
                oberon_assert_token(ctx, END);          
        }
+       else if(ctx -> token == WHILE)
+       {
+               gen_label_t * begin;
+               gen_label_t * end;
+               oberon_expr_t * cond;
+
+               begin = oberon_generator_reserve_label(ctx);
+               end = oberon_generator_reserve_label(ctx);
+
+               oberon_assert_token(ctx, WHILE);
+               oberon_generate_label(ctx, begin);
+               cond = oberon_expr(ctx);
+               if(cond -> result -> class != OBERON_TYPE_BOOLEAN)
+               {
+                       oberon_error(ctx, "condition must be boolean");
+               }
+               oberon_generate_branch(ctx, cond, false, end);
+
+               oberon_assert_token(ctx, DO);
+               oberon_statement_seq(ctx);
+               oberon_generate_goto(ctx, begin);
+
+               oberon_assert_token(ctx, END);
+               oberon_generate_label(ctx, end);
+       }
        else if(ctx -> token == RETURN)
        {
                oberon_assert_token(ctx, RETURN);