Changeset 10334c2e in mainline

Timestamp:

2012-07-30T01:40:55Z (12 years ago)

Author:

Sean Bartell <wingedtachikoma@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

20ac1a4

Parents:

d1e580a

Message:

Bithenge: add if_transform

Location:

uspace/app/bithenge

Files:

• expression.c (modified) (1 diff)
• expression.h (modified) (1 diff)
• script.c (modified) (6 diffs)
• tree.c (modified) (2 diffs)
• tree.h (modified) (1 diff)

uspace/app/bithenge/expression.c

@@ -417 +417 @@
 }
 
+typedef struct {
+        bithenge_transform_t base;
+        bithenge_expression_t *expr;
+        bithenge_transform_t *true_xform, *false_xform;
+} if_transform_t;
+
+static inline bithenge_transform_t *if_as_transform(if_transform_t *self)
+{
+        return &self->base;
+}
+
+static inline if_transform_t *transform_as_if(bithenge_transform_t *base)
+{
+        return (if_transform_t *)base;
+}
+
+static int if_transform_choose(if_transform_t *self, bithenge_scope_t *scope,
+    bool *out)
+{
+        bithenge_node_t *cond_node;
+        int rc = bithenge_expression_evaluate(self->expr, scope, &cond_node);
+        if (rc != EOK)
+                return rc;
+        if (bithenge_node_type(cond_node) != BITHENGE_NODE_BOOLEAN) {
+                bithenge_node_dec_ref(cond_node);
+                return EINVAL;
+        }
+        *out = bithenge_boolean_node_value(cond_node);
+        bithenge_node_dec_ref(cond_node);
+        return EOK;
+}
+
+static int if_transform_apply(bithenge_transform_t *base,
+    bithenge_scope_t *scope, bithenge_node_t *in, bithenge_node_t **out)
+{
+        if_transform_t *self = transform_as_if(base);
+        bool cond;
+        int rc = if_transform_choose(self, scope, &cond);
+        if (rc != EOK)
+                return rc;
+        return bithenge_transform_apply(
+            cond ? self->true_xform : self->false_xform, scope, in, out);
+}
+
+static int if_transform_prefix_length(bithenge_transform_t *base,
+    bithenge_scope_t *scope, bithenge_blob_t *in, aoff64_t *out)
+{
+        if_transform_t *self = transform_as_if(base);
+        bool cond;
+        int rc = if_transform_choose(self, scope, &cond);
+        if (rc != EOK)
+                return rc;
+        return bithenge_transform_prefix_length(
+            cond ? self->true_xform : self->false_xform, scope, in, out);
+}
+
+static void if_transform_destroy(bithenge_transform_t *base)
+{
+        if_transform_t *self = transform_as_if(base);
+        bithenge_expression_dec_ref(self->expr);
+        bithenge_transform_dec_ref(self->true_xform);
+        bithenge_transform_dec_ref(self->false_xform);
+        free(self);
+}
+
+static const bithenge_transform_ops_t if_transform_ops = {
+        .apply = if_transform_apply,
+        .prefix_length = if_transform_prefix_length,
+        .destroy = if_transform_destroy,
+};
+
+/** Create a transform that applies either of two transforms depending on a
+ * boolean expression. Takes references to @a expr, @a true_xform, and
+ * @a false_xform.
+ * @param[out] out Holds the new transform.
+ * @param expr The boolean expression to evaluate.
+ * @param true_xform The transform to apply if the expression is true.
+ * @param false_xform The transform to apply if the expression is false. */
+int bithenge_if_transform(bithenge_transform_t **out,
+    bithenge_expression_t *expr, bithenge_transform_t *true_xform,
+    bithenge_transform_t *false_xform)
+{
+        int rc;
+        if_transform_t *self = malloc(sizeof(*self));
+        if (!self) {
+                rc = ENOMEM;
+                goto error;
+        }
+
+        rc = bithenge_init_transform(if_as_transform(self), &if_transform_ops,
+            0);
+        if (rc != EOK)
+                goto error;
+
+        self->expr = expr;
+        self->true_xform = true_xform;
+        self->false_xform = false_xform;
+        *out = if_as_transform(self);
+        return EOK;
+
+error:
+        free(self);
+        bithenge_expression_dec_ref(expr);
+        bithenge_transform_dec_ref(true_xform);
+        bithenge_transform_dec_ref(false_xform);
+        return rc;
+}
+
 /** @}
  */

uspace/app/bithenge/expression.h

@@ -100 +100 @@
 int bithenge_param_wrapper(bithenge_transform_t **, bithenge_transform_t *,
     bithenge_expression_t **);
+int bithenge_if_transform(bithenge_transform_t **, bithenge_expression_t *,
+    bithenge_transform_t *, bithenge_transform_t *);
 
 #endif

uspace/app/bithenge/script.c

@@ -58 +58 @@
 
         /* Keywords */
+        TOKEN_ELSE,
+        TOKEN_FALSE,
+        TOKEN_IF,
         TOKEN_STRUCT,
         TOKEN_TRANSFORM,
+        TOKEN_TRUE,
 } token_type_t;
 
@@ -204 +208 @@
                 if (!value) {
                         error_errno(state, ENOMEM);
+                } else if (!str_cmp(value, "else")) {
+                        state->token = TOKEN_ELSE;
+                        free(value);
+                } else if (!str_cmp(value, "false")) {
+                        state->token = TOKEN_FALSE;
+                        free(value);
+                } else if (!str_cmp(value, "if")) {
+                        state->token = TOKEN_IF;
+                        free(value);
                 } else if (!str_cmp(value, "struct")) {
                         state->token = TOKEN_STRUCT;
@@ -209 +222 @@
                 } else if (!str_cmp(value, "transform")) {
                         state->token = TOKEN_TRANSFORM;
+                        free(value);
+                } else if (!str_cmp(value, "true")) {
+                        state->token = TOKEN_TRUE;
                         free(value);
                 } else {
@@ -329 +345 @@
 static bithenge_expression_t *parse_expression(state_t *state)
 {
-        if (state->token == TOKEN_INTEGER) {
+        if (state->token == TOKEN_TRUE || state->token == TOKEN_FALSE) {
+                bool val = state->token == TOKEN_TRUE;
+                next_token(state);
+                bithenge_node_t *node;
+                int rc = bithenge_new_boolean_node(&node, val);
+                if (rc != EOK) {
+                        error_errno(state, rc);
+                        return NULL;
+                }
+
+                bithenge_expression_t *expr;
+                rc = bithenge_const_expression(&expr, node);
+                if (rc != EOK) {
+                        error_errno(state, rc);
+                        return NULL;
+                }
+
+                return expr;
+        } else if (state->token == TOKEN_INTEGER) {
                 bithenge_int_t val = state->token_int;
                 next_token(state);
@@ -454 +488 @@
 
         return result;
+}
+
+static bithenge_transform_t *parse_if(state_t *state)
+{
+        expect(state, TOKEN_IF);
+        expect(state, '(');
+        bithenge_expression_t *expr = parse_expression(state);
+        expect(state, ')');
+        expect(state, '{');
+        bithenge_transform_t *true_xform = parse_transform(state);
+        expect(state, '}');
+        expect(state, TOKEN_ELSE);
+        expect(state, '{');
+        bithenge_transform_t *false_xform = parse_transform(state);
+        expect(state, '}');
+        if (state->error != EOK) {
+                bithenge_expression_dec_ref(expr);
+                bithenge_transform_dec_ref(true_xform);
+                bithenge_transform_dec_ref(false_xform);
+                return NULL;
+        }
+        bithenge_transform_t *if_xform;
+        int rc = bithenge_if_transform(&if_xform, expr, true_xform,
+            false_xform);
+        if (rc != EOK) {
+                error_errno(state, rc);
+                return NULL;
+        }
+        return if_xform;
 }
 
@@ -507 +570 @@
         if (state->token == TOKEN_IDENTIFIER) {
                 return parse_invocation(state);
+        } else if (state->token == TOKEN_IF) {
+                return parse_if(state);
         } else if (state->token == TOKEN_STRUCT) {
                 return parse_struct(state);

uspace/app/bithenge/tree.c

@@ -126 +126 @@
 }
 
+/** Initialize an internal node.
+ * @memberof bithenge_node_t
+ * @param[out] self The node.
+ * @param[in] ops The operations provided.
+ * @return EOK on success or an error code from errno.h. */
+int bithenge_init_internal_node(bithenge_node_t *self,
+    const bithenge_internal_node_ops_t *ops)
+{
+        self->type = BITHENGE_NODE_INTERNAL;
+        self->refs = 1;
+        self->internal_ops = ops;
+        return EOK;
+}
+
+static void internal_node_indestructible(bithenge_node_t *self)
+{
+        assert(false);
+}
+
+static int empty_internal_node_for_each(bithenge_node_t *base,
+    bithenge_for_each_func_t func, void *data)
+{
+        return EOK;
+}
+
+static int empty_internal_node_get(bithenge_node_t *self, bithenge_node_t *key,
+    bithenge_node_t **out)
+{
+        return ENOENT;
+}
+
+static const bithenge_internal_node_ops_t empty_internal_node_ops = {
+        .for_each = empty_internal_node_for_each,
+        .get = empty_internal_node_get,
+        .destroy = internal_node_indestructible,
+};
+
+static bithenge_node_t empty_internal_node = {
+        BITHENGE_NODE_INTERNAL,
+        1,
+        { .internal_ops = &empty_internal_node_ops },
+};
+
+/** Create an empty internal node.
+ * @param[out] out Holds the created node.
+ * @return EOK on success or an error code from errno.h. */
+int bithenge_new_empty_internal_node(bithenge_node_t **out)
+{
+        bithenge_node_inc_ref(&empty_internal_node);
+        *out = &empty_internal_node;
+        return EOK;
+}
+
 typedef struct
 {
@@ -173 +226 @@
         .destroy = simple_internal_node_destroy,
 };
-
-/** Initialize an internal node.
- * @memberof bithenge_node_t
- * @param[out] self The node.
- * @param[in] ops The operations provided.
- * @return EOK on success or an error code from errno.h. */
-int bithenge_init_internal_node(bithenge_node_t *self,
-    const bithenge_internal_node_ops_t *ops)
-{
-        self->type = BITHENGE_NODE_INTERNAL;
-        self->refs = 1;
-        self->internal_ops = ops;
-        return EOK;
-}
 
 /** Create an internal node from a set of keys and values. This function takes

uspace/app/bithenge/tree.h

@@ -161 +161 @@
 int bithenge_init_internal_node(bithenge_node_t *,
     const bithenge_internal_node_ops_t *);
+int bithenge_new_empty_internal_node(bithenge_node_t **);
 int bithenge_new_simple_internal_node(bithenge_node_t **, bithenge_node_t **,
     bithenge_int_t, bool needs_free);