harec

commit aeaef421d1e340ef046bd22afad34a16a1c1b107
parent 027edffc28616c17c13c93838f6f5d540f19eaf2
Author: Eyal Sawady <ecs@d2evs.net>
Date:   Sat, 23 Oct 2021 05:35:40 +0000

Implement offset expressions

Signed-off-by: Eyal Sawady <ecs@d2evs.net>

Diffstat:
M
src/check.c
 | 
18
++++++++++++++++--
M
src/eval.c
 | 
12
++++++++++--
M
src/gen.c
 | 
15
++++++++++++++-
M
src/parse.c
 | 
4
+++-

4 files changed, 43 insertions(+), 6 deletions(-)
diff --git a/src/check.c b/src/check.c
@@ -1985,7 +1985,21 @@ check_expr_measure(struct context *ctx,
 			ctx->store, aexpr->measure.type);
 		break;
 	case M_OFFSET:
-		assert(0); // TODO
+		if (aexpr->measure.value->type != EXPR_ACCESS) {
+			error(ctx, aexpr->measure.value->loc, expr,
+				"offset argument must be a field or tuple access");
+			return;
+		}
+		if (aexpr->measure.value->access.type != ACCESS_FIELD
+				&& aexpr->measure.value->access.type != ACCESS_TUPLE) {
+			error(ctx, aexpr->measure.value->loc, expr,
+				"offset argument must be a field or tuple access");
+			return;
+		}
+		expr->measure.value = xcalloc(1, sizeof(struct expression));
+		check_expression(ctx, aexpr->measure.value,
+			expr->measure.value, NULL);
+		break;
 	}
 }
 
@@ -3369,7 +3383,7 @@ expr_is_specified(struct context *ctx,
 		case M_SIZE:
 			return atype_is_specified(ctx, aexpr->measure.type, is_static);
 		case M_OFFSET:
-			assert(0); // TODO
+			return expr_is_specified(ctx, aexpr->measure.value, is_static);
 		}
 		assert(0);
 	case EXPR_PROPAGATE:
diff --git a/src/eval.c b/src/eval.c
@@ -472,15 +472,23 @@ eval_measurement(struct context *ctx, struct expression *in, struct expression *
 {
 	assert(in->type == EXPR_MEASURE);
 	out->type = EXPR_CONSTANT;
+	out->result = &builtin_type_size;
 	switch (in->measure.op) {
 	case M_LEN:
 		assert(0); // TODO
 	case M_SIZE:
-		out->result = &builtin_type_size;
 		out->constant.uval = in->measure.type->size;
 		return EVAL_OK;
 	case M_OFFSET:
-		assert(0); // TODO
+		if (in->measure.value->access.type == ACCESS_FIELD) {
+			out->constant.uval =
+				in->measure.value->access.field->offset;
+		} else {
+			assert(in->measure.value->access.type == ACCESS_TUPLE);
+			out->constant.uval =
+				in->measure.value->access.tvalue->offset;
+		}
+		return EVAL_OK;
 	}
 	assert(0);
 }
diff --git a/src/gen.c b/src/gen.c
@@ -2244,7 +2244,20 @@ gen_expr_measure(struct gen_context *ctx, const struct expression *expr)
 			.lval = expr->measure.type->size,
 		};
 	case M_OFFSET:
-		assert(0); // TODO
+		if (expr->measure.value->access.type == ACCESS_FIELD) {
+			return (struct gen_value){
+				.kind = GV_CONST,
+				.type = &builtin_type_size,
+				.lval = expr->measure.value->access.field->offset,
+			};
+		} else {
+			assert(expr->measure.value->access.type == ACCESS_TUPLE);
+			return (struct gen_value){
+				.kind = GV_CONST,
+				.type = &builtin_type_size,
+				.lval = expr->measure.value->access.tvalue->offset,
+			};
+		}
 	}
 	abort(); // Invariant
 }
diff --git a/src/parse.c b/src/parse.c
@@ -1124,7 +1124,9 @@ parse_measurement_expression(struct lexer *lexer)
 		break;
 	case T_OFFSET:
 		exp->measure.op = M_OFFSET;
-		assert(0); // TODO
+		// Let check error out on non-field-accesses
+		exp->measure.value = parse_expression(lexer);
+		break;
 	default:
 		synassert(false, &tok, T_SIZE, T_LEN, T_OFFSET, T_EOF);
 	}