X-Git-Url: https://deadsoftware.ru/gitweb?p=dsw-obn.git;a=blobdiff_plain;f=src%2Foberon.c;h=3b4a3747b904d0dbef91c4bb3f2ee11960e19679;hp=38e24a8da8b963669a406220cef798290e3b43ef;hb=2c43a7d73a91f64b1318306fa259a9337951a3a3;hpb=b7a2685d39da39f69ee4530dda2ec5977159dc0c

diff --git a/src/oberon.c b/src/oberon.c
index 38e24a8..3b4a374 100644
--- a/src/oberon.c
+++ b/src/oberon.c
@@ -77,7 +77,9 @@ enum {
 	EXIT,
 	LBRACE,
 	RBRACE,
-	DOTDOT
+	DOTDOT,
+	CASE,
+	BAR
 };
 
 // =======================================================================
@@ -461,6 +463,10 @@ oberon_read_ident(oberon_context_t * ctx)
 	{
 		ctx -> token = EXIT;
 	}
+	else if(strcmp(ident, "CASE") == 0)
+	{
+		ctx -> token = CASE;
+	}
 }
 
 static void
@@ -822,6 +828,10 @@ oberon_read_symbol(oberon_context_t * ctx)
 			ctx -> token = RBRACE;
 			oberon_get_char(ctx);
 			break;
+		case '|':
+			ctx -> token = BAR;
+			oberon_get_char(ctx);
+			break;
 		default:
 			oberon_error(ctx, "invalid char %c", ctx -> c);
 			break;
@@ -3171,6 +3181,101 @@ oberon_assign(oberon_context_t * ctx, oberon_expr_t * src, oberon_expr_t * dst)
 	oberon_generate_assign(ctx, src, dst);
 }
 
+static oberon_expr_t *
+oberon_case_labels(oberon_context_t * ctx, oberon_expr_t * val)
+{
+	oberon_expr_t * e1;
+	oberon_expr_t * e2;
+	oberon_expr_t * cond;
+	oberon_expr_t * cond2;
+
+	e1 = (oberon_expr_t *) oberon_const_expr(ctx);
+	oberon_autocast_to(ctx, e1, val -> result);
+	
+	e2 = NULL;
+	if(ctx -> token == DOTDOT)
+	{
+		oberon_assert_token(ctx, DOTDOT);
+		e2 = (oberon_expr_t *) oberon_const_expr(ctx);
+		oberon_autocast_to(ctx, e2, val -> result);
+	}
+
+	if(e2 == NULL)
+	{
+		/* val == e1 */
+		cond = oberon_make_bin_op(ctx, EQUAL, val, e1);
+	}
+	else
+	{
+		/* val >= e1 && val <= e2 */
+		cond = oberon_make_bin_op(ctx, GEQ, val, e1);
+		cond2 = oberon_make_bin_op(ctx, LEQ, val, e2);
+		cond = oberon_make_bin_op(ctx, AND, cond, cond2);
+	}
+
+	return cond;
+}
+
+static void
+oberon_case(oberon_context_t * ctx, oberon_expr_t * val, gen_label_t * end)
+{
+	oberon_expr_t * cond;
+	oberon_expr_t * cond2;
+	gen_label_t * this_end;
+
+	if(ISEXPR(ctx -> token))
+	{
+		this_end = oberon_generator_reserve_label(ctx);
+
+		cond = oberon_case_labels(ctx, val);
+		while(ctx -> token == COMMA)
+		{
+			oberon_assert_token(ctx, COMMA);
+			/* cond || cond2 */
+			cond2 = oberon_case_labels(ctx, val);
+			cond = oberon_make_bin_op(ctx, OR, cond, cond2);
+		}
+		oberon_assert_token(ctx, COLON);
+
+		oberon_generate_branch(ctx, cond, false, this_end);
+		oberon_statement_seq(ctx);
+		oberon_generate_goto(ctx, end);
+
+		oberon_generate_label(ctx, this_end);
+	}
+}
+
+static void
+oberon_case_statement(oberon_context_t * ctx)
+{
+	oberon_expr_t * val;
+	oberon_expr_t * expr;
+	gen_label_t * end;
+
+	end = oberon_generator_reserve_label(ctx);
+
+	oberon_assert_token(ctx, CASE);
+	expr = oberon_expr(ctx);
+	val = oberon_make_temp_var_item(ctx, expr -> result);
+	oberon_assign(ctx, expr, val);
+	oberon_assert_token(ctx, OF);
+	oberon_case(ctx, val, end);
+	while(ctx -> token == BAR)
+	{
+		oberon_assert_token(ctx, BAR);
+		oberon_case(ctx, val, end);
+	}
+
+	if(ctx -> token == ELSE)
+	{
+		oberon_assert_token(ctx, ELSE);
+		oberon_statement_seq(ctx);
+	}
+
+	oberon_generate_label(ctx, end);
+	oberon_assert_token(ctx, END);
+}
+
 static void
 oberon_statement(oberon_context_t * ctx)
 {
@@ -3377,6 +3482,10 @@ oberon_statement(oberon_context_t * ctx)
 		}
 		oberon_generate_goto(ctx, ctx -> decl -> exit_label);
 	}
+	else if(ctx -> token == CASE)
+	{
+		oberon_case_statement(ctx);
+	}
 	else if(ctx -> token == RETURN)
 	{
 		oberon_assert_token(ctx, RETURN);