Switch C files to CC files (#309)

Mostly this involves adding additional casts. Though there are a few
more substantial changes:

* The default method for relocating parser stacks no longer works
  because Bison assumes that C++ values can't be memcpy'd. Ours can, but
  there's no easy way to make the generated code do the right thing, so
  we do it manually
* Removed all uses of WabtBool and replaced with bool
* Renamed all uses of export and mutable -> export_ and mutable_
* Casting an invalid value to an enum triggers ubsan, so we have to be a
  little more careful about when we do it (see binary-reader.c:read_sections())
* It's illegal to forward-declare enums, so we just #include instead.
* Designated initializers are not allowed in g++, so we have to switch
  them to lazily initialized structures instead. Pretty horrible, so it
  will be nice to have a better solution for C++.

1 files changed, 179 insertions, 0 deletions

diff --git a/src/binding-hash.cc b/src/binding-hash.cc
new file mode 100644
index 00000000..59249571
--- /dev/null
+++ b/src/binding-hash.cc
@@ -0,0 +1,179 @@
+/*
+ * Copyright 2016 WebAssembly Community Group participants
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "binding-hash.h"
+
+#define INITIAL_HASH_CAPACITY 8
+
+static size_t hash_name(const WabtStringSlice* name) {
+  // FNV-1a hash
+  const uint32_t fnv_prime = 0x01000193;
+  const uint8_t* bp = (const uint8_t*)name->start;
+  const uint8_t* be = bp + name->length;
+  uint32_t hval = 0x811c9dc5;
+  while (bp < be) {
+    hval ^= (uint32_t)*bp++;
+    hval *= fnv_prime;
+  }
+  return hval;
+}
+
+static WabtBindingHashEntry* hash_main_entry(const WabtBindingHash* hash,
+                                             const WabtStringSlice* name) {
+  return &hash->entries.data[hash_name(name) % hash->entries.capacity];
+}
+
+bool wabt_hash_entry_is_free(const WabtBindingHashEntry* entry) {
+  return !entry->binding.name.start;
+}
+
+static WabtBindingHashEntry* hash_new_entry(WabtBindingHash* hash,
+                                            const WabtStringSlice* name) {
+  WabtBindingHashEntry* entry = hash_main_entry(hash, name);
+  if (!wabt_hash_entry_is_free(entry)) {
+    assert(hash->free_head);
+    WabtBindingHashEntry* free_entry = hash->free_head;
+    hash->free_head = free_entry->next;
+    if (free_entry->next)
+      free_entry->next->prev = NULL;
+
+    /* our main position is already claimed. Check to see if the entry in that
+     * position is in its main position */
+    WabtBindingHashEntry* other_entry =
+        hash_main_entry(hash, &entry->binding.name);
+    if (other_entry == entry) {
+      /* yes, so add this new entry to the chain, even if it is already there */
+      /* add as the second entry in the chain */
+      free_entry->next = entry->next;
+      entry->next = free_entry;
+      entry = free_entry;
+    } else {
+      /* no, move the entry to the free entry */
+      assert(!wabt_hash_entry_is_free(other_entry));
+      while (other_entry->next != entry)
+        other_entry = other_entry->next;
+
+      other_entry->next = free_entry;
+      *free_entry = *entry;
+      entry->next = NULL;
+    }
+  } else {
+    /* remove from the free list */
+    if (entry->next)
+      entry->next->prev = entry->prev;
+    if (entry->prev)
+      entry->prev->next = entry->next;
+    else
+      hash->free_head = entry->next;
+    entry->next = NULL;
+  }
+
+  WABT_ZERO_MEMORY(entry->binding);
+  entry->binding.name = *name;
+  entry->prev = NULL;
+  /* entry->next is set above */
+  return entry;
+}
+
+static void hash_resize(WabtBindingHash* hash, size_t desired_capacity) {
+  WabtBindingHash new_hash;
+  WABT_ZERO_MEMORY(new_hash);
+  /* TODO(binji): better plural */
+  wabt_reserve_binding_hash_entrys(&new_hash.entries, desired_capacity);
+
+  /* update the free list */
+  size_t i;
+  for (i = 0; i < new_hash.entries.capacity; ++i) {
+    WabtBindingHashEntry* entry = &new_hash.entries.data[i];
+    if (new_hash.free_head)
+      new_hash.free_head->prev = entry;
+
+    WABT_ZERO_MEMORY(entry->binding.name);
+    entry->next = new_hash.free_head;
+    new_hash.free_head = entry;
+  }
+  new_hash.free_head->prev = NULL;
+
+  /* copy from the old hash to the new hash */
+  for (i = 0; i < hash->entries.capacity; ++i) {
+    WabtBindingHashEntry* old_entry = &hash->entries.data[i];
+    if (wabt_hash_entry_is_free(old_entry))
+      continue;
+
+    WabtStringSlice* name = &old_entry->binding.name;
+    WabtBindingHashEntry* new_entry = hash_new_entry(&new_hash, name);
+    new_entry->binding = old_entry->binding;
+  }
+
+  /* we are sharing the WabtStringSlices, so we only need to destroy the old
+   * binding vector */
+  wabt_destroy_binding_hash_entry_vector(&hash->entries);
+  *hash = new_hash;
+}
+
+WabtBinding* wabt_insert_binding(WabtBindingHash* hash,
+                                 const WabtStringSlice* name) {
+  if (hash->entries.size == 0)
+    hash_resize(hash, INITIAL_HASH_CAPACITY);
+
+  if (!hash->free_head) {
+    /* no more free space, allocate more */
+    hash_resize(hash, hash->entries.capacity * 2);
+  }
+
+  WabtBindingHashEntry* entry = hash_new_entry(hash, name);
+  assert(entry);
+  hash->entries.size++;
+  return &entry->binding;
+}
+
+int wabt_find_binding_index_by_name(const WabtBindingHash* hash,
+                                    const WabtStringSlice* name) {
+  if (hash->entries.capacity == 0)
+    return -1;
+
+  WabtBindingHashEntry* entry = hash_main_entry(hash, name);
+  do {
+    if (wabt_string_slices_are_equal(&entry->binding.name, name))
+      return entry->binding.index;
+
+    entry = entry->next;
+  } while (entry && !wabt_hash_entry_is_free(entry));
+  return -1;
+}
+
+void wabt_remove_binding(WabtBindingHash* hash, const WabtStringSlice* name) {
+  int index = wabt_find_binding_index_by_name(hash, name);
+  if (index == -1)
+    return;
+
+  WabtBindingHashEntry* entry = &hash->entries.data[index];
+  wabt_destroy_string_slice(&entry->binding.name);
+  WABT_ZERO_MEMORY(*entry);
+}
+
+static void destroy_binding_hash_entry(WabtBindingHashEntry* entry) {
+  wabt_destroy_string_slice(&entry->binding.name);
+}
+
+void wabt_destroy_binding_hash(WabtBindingHash* hash) {
+  /* Can't use WABT_DESTROY_VECTOR_AND_ELEMENTS, because it loops over size, not
+   * capacity. */
+  size_t i;
+  for (i = 0; i < hash->entries.capacity; ++i)
+    destroy_binding_hash_entry(&hash->entries.data[i]);
+  wabt_destroy_binding_hash_entry_vector(&hash->entries);
+}