commit 3fdebb5635f4d7e58a11ad7797dc56cae2700cb6
parent d85361a88b8ab4ae745bfa49feef1da8220bc3bd
Author: Drew DeVault <sir@cmpwn.com>
Date: Fri, 2 Jul 2021 12:01:16 -0400
gen: implement basic access expressions
Signed-off-by: Drew DeVault <sir@cmpwn.com>
Diffstat:
| M | src/gen.c | | | 96 | +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ |
1 file changed, 96 insertions(+), 0 deletions(-)
diff --git a/src/gen.c b/src/gen.c
@@ -86,10 +86,104 @@ load_temp(struct gen_context *ctx,
}
}
+static const struct gen_binding *
+binding_lookup(struct gen_context *ctx, const struct scope_object *obj)
+{
+ for (struct gen_binding *binding = ctx->bindings;
+ binding; binding = binding->next) {
+ if (binding->object == obj) {
+ return binding;
+ }
+ }
+ abort(); // Invariant
+}
+
+// Generates a copy operation from one gen temporary to another. For primitive
+// types this is a load+store operation; for aggregate types this may emit more
+// complex code or a memcpy.
+static void
+gen_copy(struct gen_context *ctx,
+ const struct gen_temp *dest,
+ const struct gen_temp *src)
+{
+ const struct type *dtype = type_dealias(dest->type);
+ switch (dtype->storage) {
+ case STORAGE_BOOL:
+ case STORAGE_CHAR:
+ case STORAGE_ENUM:
+ case STORAGE_F32:
+ case STORAGE_F64:
+ case STORAGE_I16:
+ case STORAGE_I32:
+ case STORAGE_I64:
+ case STORAGE_I8:
+ case STORAGE_INT:
+ case STORAGE_NULL:
+ case STORAGE_RUNE:
+ case STORAGE_SIZE:
+ case STORAGE_U16:
+ case STORAGE_U32:
+ case STORAGE_U64:
+ case STORAGE_U8:
+ case STORAGE_UINT:
+ case STORAGE_UINTPTR:
+ // fallthrough
+ break;
+ case STORAGE_ARRAY:
+ case STORAGE_FUNCTION:
+ case STORAGE_POINTER:
+ case STORAGE_SLICE:
+ case STORAGE_STRING:
+ case STORAGE_STRUCT:
+ case STORAGE_TAGGED:
+ case STORAGE_TUPLE:
+ case STORAGE_UNION:
+ assert(0); // TODO
+ case STORAGE_ALIAS:
+ case STORAGE_FCONST:
+ case STORAGE_ICONST:
+ case STORAGE_VOID:
+ abort(); // Invariant
+ }
+
+ // Copy between types which have a native qbe representation
+ struct qbe_value value = {0}, dtemp = {0};
+ load_temp(ctx, &value, src);
+ qval_temp(ctx, &dtemp, dest);
+
+ enum qbe_instr instr = store_for_type(ctx, dtype);
+ pushi(ctx->current, NULL, instr, &value, &dtemp, NULL);
+}
+
static void gen_expr(struct gen_context *ctx,
const struct expression *expr, struct gen_temp *out);
static void
+gen_access_object(struct gen_context *ctx,
+ const struct scope_object *obj,
+ struct gen_temp *out)
+{
+ const struct gen_binding *binding = binding_lookup(ctx, obj);
+ gen_copy(ctx, out, &binding->temp);
+}
+
+static void
+gen_expr_access(struct gen_context *ctx,
+ const struct expression *expr,
+ struct gen_temp *out)
+{
+ switch (expr->access.type) {
+ case ACCESS_IDENTIFIER:
+ gen_access_object(ctx, expr->access.object, out);
+ break;
+ case ACCESS_INDEX:
+ case ACCESS_FIELD:
+ case ACCESS_TUPLE:
+ assert(0); // TODO
+ }
+}
+
+static void
gen_expr_binding(struct gen_context *ctx,
const struct expression *expr,
struct gen_temp *out)
@@ -267,6 +361,8 @@ gen_expr(struct gen_context *ctx,
{
switch (expr->type) {
case EXPR_ACCESS:
+ gen_expr_access(ctx, expr, out);
+ break;
case EXPR_ALLOC:
case EXPR_APPEND:
case EXPR_ASSERT:
