commit d5845af7f65f881a400b55dce59181d7a7bd2bd2
parent a2713249b19b81223cac003d65a94bbd597fe19a
Author: Drew DeVault <sir@cmpwn.com>
Date: Fri, 15 Jan 2021 14:05:35 -0500
gen: implement casting to tagged union
Diffstat:
| M | src/gen.c | | | 64 | ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-- |
1 file changed, 62 insertions(+), 2 deletions(-)
diff --git a/src/gen.c b/src/gen.c
@@ -662,6 +662,58 @@ gen_expr_call(struct gen_context *ctx,
}
static void
+gen_cast_to_tagged(struct gen_context *ctx,
+ const struct expression *expr,
+ const struct qbe_value *out,
+ const struct type *from)
+{
+ if (from->storage == TYPE_STORAGE_TAGGED_UNION) {
+ assert(0); // TODO
+ }
+
+ struct qbe_value tag = {0}, ptr = {0}, offs = {0};
+ gen_temp(ctx, &ptr, &qbe_long, "ptr.%d");
+ constl(&offs, 8);
+ constl(&tag, expr->result->id);
+ pushi(ctx->current, &ptr, Q_COPY, out, NULL);
+ pushi(ctx->current, NULL, Q_STOREL, &tag, &ptr, NULL);
+ pushi(ctx->current, &ptr, Q_ADD, &ptr, &offs, NULL);
+ ptr.type = qtype_for_type(ctx, expr->result, false);
+ ptr.indirect = type_is_aggregate(expr->cast.value->result);
+ gen_expression(ctx, expr->cast.value, &ptr);
+}
+
+static void
+gen_cast_from_tagged(struct gen_context *ctx,
+ const struct expression *expr,
+ const struct qbe_value *out,
+ const struct type *to)
+{
+ if (to->storage == TYPE_STORAGE_TAGGED_UNION) {
+ assert(0); // TODO
+ }
+
+ // XXX: This has not been fully tested pending rules implementation
+ struct qbe_value ptr = {0}, offs = {0}, temp = {0};
+ gen_temp(ctx, &ptr,
+ qtype_for_type(ctx, expr->result, false), "tagged.%d");
+ gen_expression(ctx, expr->cast.value, &ptr);
+
+ constl(&offs, 8);
+ pushi(ctx->current, &ptr, Q_ADD, &ptr, &offs, NULL);
+ ptr.type = qtype_for_type(ctx, expr->result, false);
+ ptr.indirect = type_is_aggregate(expr->result);
+ if (ptr.indirect) {
+ gen_loadtemp(ctx, &temp, &ptr,
+ qtype_for_type(ctx, expr->result, false),
+ type_is_signed(expr->result));
+ gen_store(ctx, out, &temp);
+ } else {
+ gen_store(ctx, out, &ptr);
+ }
+}
+
+static void
gen_expr_cast(struct gen_context *ctx,
const struct expression *expr,
const struct qbe_value *out)
@@ -671,6 +723,12 @@ gen_expr_cast(struct gen_context *ctx,
if (to->storage == from->storage) {
gen_expression(ctx, expr->cast.value, out);
return;
+ } else if (to->storage == TYPE_STORAGE_TAGGED_UNION) {
+ gen_cast_to_tagged(ctx, expr, out, from);
+ return;
+ } else if (from->storage == TYPE_STORAGE_TAGGED_UNION) {
+ gen_cast_from_tagged(ctx, expr, out, to);
+ return;
}
bool is_signed = type_is_signed(from);
@@ -702,7 +760,10 @@ gen_expr_cast(struct gen_context *ctx,
}
gen_expression(ctx, expr->cast.value, &in);
+ // Used for various casts
enum qbe_instr op;
+ struct qbe_value ptr = {0}, offs = {0}, len = {0};
+
switch (to->storage) {
case TYPE_STORAGE_CHAR:
case TYPE_STORAGE_U8:
@@ -746,7 +807,6 @@ gen_expr_cast(struct gen_context *ctx,
break;
case TYPE_STORAGE_F32:
case TYPE_STORAGE_F64:
- case TYPE_STORAGE_TAGGED_UNION:
case TYPE_STORAGE_ENUM:
assert(0); // TODO
case TYPE_STORAGE_ARRAY:
@@ -762,7 +822,6 @@ gen_expr_cast(struct gen_context *ctx,
break;
}
// XXX: ARCH
- struct qbe_value ptr = {0}, offs = {0}, len = {0};
gen_temp(ctx, &ptr, &qbe_long, "ptr.%d");
constl(&offs, 8);
constl(&len, from->array.length);
@@ -779,6 +838,7 @@ gen_expr_cast(struct gen_context *ctx,
pushi(ctx->current, &result, Q_COPY, &in, NULL);
break;
case TYPE_STORAGE_ALIAS:
+ case TYPE_STORAGE_TAGGED_UNION:
assert(0); // Handled above
case TYPE_STORAGE_BOOL:
case TYPE_STORAGE_FUNCTION:
