harec

commit eeb39ccb3d73786467b62e514fe3d79f25e934d1
parent bae5737c457a55d25c293cef4412abeb47d03289
Author: Drew DeVault <sir@cmpwn.com>
Date:   Tue, 31 Aug 2021 11:11:23 +0200

all: lay groundwork for yield expressions

Signed-off-by: Drew DeVault <sir@cmpwn.com>

Diffstat:
M
include/ast.h
 | 
1
+
M
include/expr.h
 | 
2
++
M
include/lex.h
 | 
3
++-
M
src/check.c
 | 
4
++++
M
src/eval.c
 | 
1
+
M
src/gen.c
 | 
2
++
M
src/lex.c
 | 
1
+
M
src/parse.c
 | 
30
++++++++++++++++++++++++++++--

8 files changed, 41 insertions(+), 3 deletions(-)
diff --git a/include/ast.h b/include/ast.h
@@ -213,6 +213,7 @@ struct ast_expression_constant {
 
 struct ast_expression_control {
 	char *label;
+	struct ast_expression *value; // Only set for yield
 };
 
 struct ast_expression_defer {
diff --git a/include/expr.h b/include/expr.h
@@ -37,6 +37,7 @@ enum expr_type {
 	EXPR_SWITCH,
 	EXPR_TUPLE,
 	EXPR_UNARITHM,
+	EXPR_YIELD,
 };
 
 enum access_type {
@@ -210,6 +211,7 @@ struct expression_constant {
 struct expression_control {
 	char *label;
 	const struct scope *scope;
+	struct expression *value; // Only set for yield
 };
 
 struct expression_defer {
diff --git a/include/lex.h b/include/lex.h
@@ -67,7 +67,8 @@ enum lexical_token {
 	T_UNION,
 	T_USE,
 	T_VOID,
-	T_LAST_KEYWORD = T_VOID,
+	T_YIELD,
+	T_LAST_KEYWORD = T_YIELD,
 
 	// Operators
 	T_BANDEQ,
diff --git a/src/check.c b/src/check.c
@@ -2646,6 +2646,8 @@ check_expression(struct context *ctx,
 	case EXPR_UNARITHM:
 		check_expr_unarithm(ctx, aexpr, expr, hint);
 		break;
+	case EXPR_YIELD:
+		assert(0); // TODO
 	}
 	assert(expr->result);
 	if (hint && hint->storage == STORAGE_VOID) {
@@ -3178,6 +3180,8 @@ expr_is_specified(struct context *ctx, const struct ast_expression *aexpr)
 		return true;
 	case EXPR_UNARITHM:
 		return expr_is_specified(ctx, aexpr->unarithm.operand);
+	case EXPR_YIELD:
+		return expr_is_specified(ctx, aexpr->control.value);
 	}
 	assert(0); // Unreachable
 }
diff --git a/src/eval.c b/src/eval.c
@@ -731,6 +731,7 @@ eval_expr(struct context *ctx, struct expression *in, struct expression *out)
 	case EXPR_PROPAGATE:
 	case EXPR_RETURN:
 	case EXPR_SWITCH:
+	case EXPR_YIELD:
 		// Excluded from translation-compatible subset
 		return EVAL_INVALID;
 	}
diff --git a/src/gen.c b/src/gen.c
@@ -2556,6 +2556,8 @@ gen_expr(struct gen_context *ctx, const struct expression *expr)
 		return gen_expr_switch_with(ctx, expr, NULL);
 	case EXPR_UNARITHM:
 		return gen_expr_unarithm(ctx, expr);
+	case EXPR_YIELD:
+		assert(0); // TODO
 	case EXPR_SLICE:
 	case EXPR_STRUCT:
 	case EXPR_TUPLE:
diff --git a/src/lex.c b/src/lex.c
@@ -75,6 +75,7 @@ static const char *tokens[] = {
 	[T_UNION] = "union",
 	[T_USE] = "use",
 	[T_VOID] = "void",
+	[T_YIELD] = "yield",
 
 	// Operators
 	[T_BANDEQ] = "&=",
diff --git a/src/parse.c b/src/parse.c
@@ -2018,7 +2018,6 @@ parse_control_statement(struct lexer *lexer)
 	case T_RETURN:
 		exp->type = EXPR_RETURN;
 		exp->_return.value = NULL;
-		struct token tok;
 		switch (lex(lexer, &tok)) {
 		case T_SEMICOLON:
 		case T_COMMA:
@@ -2030,8 +2029,33 @@ parse_control_statement(struct lexer *lexer)
 			break;
 		}
 		break;
+	case T_YIELD:
+		exp->type = EXPR_YIELD;
+		exp->control.value = NULL;
+		switch (lex(lexer, &tok)) {
+		case T_SEMICOLON:
+			unlex(lexer, &tok);
+			break;
+		case T_LABEL:
+			exp->control.label = tok.name;
+			switch (lex(lexer, &tok)) {
+			case T_COMMA:
+				exp->control.value = parse_expression(lexer);
+				break;
+			default:
+				unlex(lexer, &tok);
+				break;
+			}
+			break;
+		default:
+			unlex(lexer, &tok);
+			exp->control.value = parse_expression(lexer);
+			break;
+		}
+		break;
 	default:
-		synassert(false, &tok, T_BREAK, T_CONTINUE, T_RETURN, T_EOF);
+		synassert(false, &tok,
+			T_BREAK, T_CONTINUE, T_RETURN, T_YIELD, T_EOF);
 	}
 	return exp;
 }
@@ -2124,6 +2148,7 @@ parse_expression(struct lexer *lexer)
 	case T_BREAK:
 	case T_CONTINUE:
 	case T_RETURN:
+	case T_YIELD:
 	case T_DEFER:
 	case T_FOR:
 	case T_LABEL:
@@ -2135,6 +2160,7 @@ parse_expression(struct lexer *lexer)
 		case T_BREAK:
 		case T_CONTINUE:
 		case T_RETURN:
+		case T_YIELD:
 			unlex(lexer, &tok);
 			value = parse_control_statement(lexer);
 			break;