X-Git-Url: https://code.kerkeslager.com/?a=blobdiff_plain;f=templates%2Fprogram.c;h=17669674a01e41d8ca4a1eb8c514a0daef6ef658;hb=3297817843cd6bd087505a70d8e108f1baa35cff;hp=0f79b14cd1d5c82a2734fd8c05139c3ab36ee9cc;hpb=98d42eb47acf01ace76d57942404c09132d51f79;p=fur

diff --git a/templates/program.c b/templates/program.c
index 0f79b14..1766967 100644
--- a/templates/program.c
+++ b/templates/program.c
@@ -4,28 +4,44 @@
 #include <stdlib.h>
 #include <string.h>
 
+/* Some terminology used in function names:
+ * - initialize: These functions take a pointer and potentially some other arguments, and use those
+ *   to initialize the value pointed to by self. Initialize functions DO NOT allocate the function,
+ *   so they can be used to initialize stack-allocated variables.
+ * - construct: This allocates a value for a pointer, initializes it, and returns it. This is for
+ *   heap-allocated values. It may be as simple as allocating the memory, calling an initialize, and
+ *   returning it.
+ * - deinitialize: These functions dereference or free any objects pointed to by the self pointer's
+ *   value, but they don't actually free the self pointer. This is useful for stack-allocated objects
+ *   which point to heap-allocated objects.
+ * - destruct: This dereferences or frees memory pointed to by the self argument, and all the
+ *   pointers on the self argument.
+ */
+
 {% for standard_library in standard_libraries %}
 #include <{{standard_library}}>
 {% endfor %}
 
-struct String;
-typedef struct String String;
 enum Type;
 typedef enum Type Type;
 union Instance;
 typedef union Instance Instance;
 struct Object;
 typedef struct Object Object;
-struct Runtime;
-typedef struct Runtime Runtime;
+struct EnvironmentNode;
+typedef struct EnvironmentNode EnvironmentNode;
+struct Environment;
+typedef struct Environment Environment;
+struct EnvironmentPool;
+typedef struct EnvironmentPool EnvironmentPool;
 
-struct String
-{
-  size_t length;
-  char* characters;
+const char* const STRING_LITERAL_LIST[] = {
+{% for string_literal in string_literal_list %}
+  "{{ string_literal }}",
+{% endfor %}
 };
 
-const char * const SYMBOL_LIST[] = {
+const char* const SYMBOL_LIST[] = {
 {% for symbol in symbol_list %}
   "{{ symbol }}",
 {% endfor %}
@@ -33,14 +49,38 @@ const char * const SYMBOL_LIST[] = {
 
 enum Type
 {
+  BOOLEAN,
+  CLOSURE,
   INTEGER,
-  STRING
+  LIST,
+  STRING,
+  VOID
+};
+
+struct Closure;
+typedef struct Closure Closure;
+struct Closure
+{
+  Environment* closed;
+  Object (*call)(EnvironmentPool*, Environment*, size_t, Object*);
+};
+
+struct List;
+typedef struct List List;
+struct List
+{
+  size_t allocated;
+  size_t length;
+  Object* items;
 };
 
 union Instance
 {
+  bool boolean;
+  Closure closure;
   int32_t integer;
-  String* string;
+  List list;
+  const char* string;
 };
 
 struct Object
@@ -49,8 +89,42 @@ struct Object
   Instance instance;
 };
 
-struct EnvironmentNode;
-typedef struct EnvironmentNode EnvironmentNode;
+const Object builtin$true = { BOOLEAN, (Instance)(bool){ true } };
+const Object builtin$false = { BOOLEAN, (Instance)(bool){ false } };
+const Object builtin$nil = { VOID, { 0 } };
+
+Object List_construct(size_t allocate)
+{
+  Object* items = malloc(sizeof(Object) * allocate);
+  Object result = { LIST, (Instance)(List){ allocate, 0, items } };
+  return result;
+}
+
+void List_append(Object* list, Object item)
+{
+  assert(list->type == LIST);
+
+  if(list->instance.list.allocated == list->instance.list.length)
+  {
+    list->instance.list.allocated *= 2;
+    list->instance.list.items = realloc(
+      list->instance.list.items,
+      sizeof(Object) * list->instance.list.allocated
+    );
+  }
+
+  list->instance.list.items[list->instance.list.length] = item;
+  list->instance.list.length++;
+}
+
+Object List_get(Object* list, Object index)
+{
+  assert(list->type == LIST);
+  assert(index.type == INTEGER);
+
+  return list->instance.list.items[index.instance.integer];
+}
+
 struct EnvironmentNode
 {
   const char* key;
@@ -58,33 +132,87 @@ struct EnvironmentNode
   EnvironmentNode* next;
 };
 
-struct Environment;
-typedef struct Environment Environment;
 struct Environment
 {
+  bool mark;
+  bool live;
+
+  Environment* parent;
   EnvironmentNode* root;
 };
 
-Environment* Environment_construct()
+void Environment_initialize(Environment* self, Environment* parent)
 {
-  // TODO Handle malloc returning NULL
-  Environment* result = malloc(sizeof(Environment));
-  result->root = NULL;
-  return result;
+  self->parent = parent;
+  self->root = NULL;
+
+  // We are currently only ever initializing environments at the beginning of running functions, so
+  // for now at least we can assume that we want it to be live immediately.
+  self->live = true;
 }
 
-void Environment_destruct(Environment* self)
+void Environment_deinitialize(Environment* self)
 {
   EnvironmentNode* next;
   for(EnvironmentNode* node = self->root; node != NULL; node = next)
   {
-    // We don't need to destruct the permanent strings, because those will be destructed at the end when the Runtime is destructed
-    // The above comment represents all heap-allocated objects currently, so we don't need to destruct Objects (yet)
     next = node->next;
+
+    switch(node->value.type)
+    {
+      case BOOLEAN:
+      case CLOSURE:
+      case INTEGER:
+      case STRING:
+      case VOID:
+        break;
+
+      case LIST:
+        free(node->value.instance.list.items);
+        break;
+
+      default:
+        assert(false);
+    }
+
     free(node);
   }
 }
 
+void Environment_setLive(Environment* self, bool live)
+{
+  self->live = live;
+}
+
+void Environment_mark(Environment* self)
+{
+  if(self == NULL) return;
+  if(self->mark) return; // Prevents infinite recursion in the case of cycles
+
+  self->mark = true;
+
+  Environment_mark(self->parent);
+
+  for(EnvironmentNode* node = self->root; node != NULL; node = node->next)
+  {
+    switch(node->value.type)
+    {
+      case BOOLEAN:
+      case INTEGER:
+      case STRING:
+      case VOID:
+        break;
+
+      case CLOSURE:
+        Environment_mark(node->value.instance.closure.closed);
+        break;
+
+      default:
+        assert(false);
+    }
+  }
+}
+
 // This need not be thread safe because environments exist on one thread only
 void Environment_set(Environment* self, const char* const key, Object value)
 {
@@ -99,69 +227,146 @@ Object Environment_get(Environment* self, const char* const symbol)
 {
   for(EnvironmentNode* node = self->root; node != NULL; node = node->next)
   {
-    // We can compare pointers because pointers are unique in the SYMBOLS_LIST
+    // We can compare pointers because pointers are unique in the SYMBOL_LIST
     if(node->key == symbol)
     {
       return node->value;
     }
   }
 
+  if(self->parent != NULL)
+  {
+    return Environment_get(self->parent, symbol);
+  }
+
   // TODO Handle symbol errors
   assert(false);
 }
 
-
-struct Runtime
+# define POOL_SIZE 64
+struct EnvironmentPool
 {
-  size_t permanentStringsLength;
-  size_t permanentStringsAllocated;
-  String** permanentStrings;
+  int8_t freeIndex;
+  bool allocatedFlags[POOL_SIZE];
+  Environment environments[POOL_SIZE];
+  EnvironmentPool* overflow;
 };
 
-Runtime* Runtime_construct()
+EnvironmentPool* EnvironmentPool_construct();
+void EnvironmentPool_initialize(EnvironmentPool*);
+void EnvironmentPool_deinitialize(EnvironmentPool*);
+void EnvironmentPool_destruct(EnvironmentPool*);
+
+EnvironmentPool* EnvironmentPool_construct()
 {
-  Runtime* result = malloc(sizeof(Runtime));
-  result->permanentStringsLength = 0;
-  result->permanentStringsAllocated = 0;
-  result->permanentStrings = NULL;
+  EnvironmentPool* result = malloc(sizeof(EnvironmentPool));
+  EnvironmentPool_initialize(result);
   return result;
 }
 
-void Runtime_destruct(Runtime* self)
+void EnvironmentPool_initialize(EnvironmentPool* self)
 {
-  for(size_t i = 0; i < self->permanentStringsLength; i++)
+  self->overflow = NULL;
+  self->freeIndex = 0;
+
+  for(size_t i = 0; i < POOL_SIZE; i++)
   {
-    free(self->permanentStrings[i]);
+    self->allocatedFlags[i] = false;
+    self->environments[i].live = false;
   }
+}
 
-  free(self->permanentStrings);
+void EnvironmentPool_deinitialize(EnvironmentPool* self)
+{
+  // We can assume if this is being called, none of the Environments are live
+  for(int8_t i = 0; i < POOL_SIZE; i++)
+  {
+    if(self->allocatedFlags[i]) Environment_deinitialize(&(self->environments[i]));
+  }
+
+  EnvironmentPool_destruct(self->overflow);
+}
+
+void EnvironmentPool_destruct(EnvironmentPool* self)
+{
+  if(self == NULL) return;
+  EnvironmentPool_deinitialize(self);
   free(self);
 }
 
-void Runtime_addPermanentString(Runtime* self, String* string)
+void EnvironmentPool_GC(EnvironmentPool* self)
 {
-  // TODO Make this function thread-safe
-  if(self->permanentStringsLength == self->permanentStringsAllocated)
+  // Unmark all the environments
+  for(EnvironmentPool* current = self; current != NULL; current = current->overflow)
   {
-    if(self->permanentStringsAllocated == 0)
+    for(int8_t i = 0; i < POOL_SIZE; i++)
     {
-      self->permanentStringsAllocated = 8;
+      current->environments[i].mark = false;
     }
-    else
+  }
+
+  // Mark live enviroments and environments referenced by live environments
+  for(EnvironmentPool* current = self; current != NULL; current = current->overflow)
+  {
+    for(int8_t i = 0; i < POOL_SIZE; i++)
     {
-      self->permanentStringsAllocated = self->permanentStringsAllocated * 2;
+      if(current->environments[i].live)
+      {
+        Environment_mark(&(current->environments[i]));
+      }
     }
+  }
 
-    self->permanentStrings = realloc(
-      self->permanentStrings,
-      sizeof(String*) * self->permanentStringsAllocated
-    );
+  // TODO We never free pools until the very end--we could free a pool if two pools are empty
+  for(EnvironmentPool* current = self; current != NULL; current = current->overflow)
+  {
+    for(int8_t i = POOL_SIZE - 1; i >= 0; i--)
+    {
+      if(!current->environments[i].mark && current->allocatedFlags[i])
+      {
+        Environment_deinitialize(&(current->environments[i]));
+        current->allocatedFlags[i] = false;
+        current->freeIndex = i;
+      }
+    }
+  }
+}
 
-    // TODO Handle realloc returning NULL
+Environment* EnvironmentPool_allocate(EnvironmentPool* self)
+{
+  for(EnvironmentPool* current = self; current != NULL; current = current->overflow)
+  {
+    for(; current->freeIndex < POOL_SIZE; current->freeIndex++)
+    {
+      if(!current->allocatedFlags[current->freeIndex])
+      {
+        current->allocatedFlags[current->freeIndex] = true;
+        return &(current->environments[current->freeIndex]);
+      }
+    }
+  }
+
+  EnvironmentPool_GC(self);
+
+  EnvironmentPool* previous;
+  for(EnvironmentPool* current = self; current != NULL; current = current->overflow)
+  {
+    for(; current->freeIndex < POOL_SIZE; current->freeIndex++)
+    {
+      if(!current->allocatedFlags[current->freeIndex])
+      {
+        current->allocatedFlags[current->freeIndex] = true;
+        return &(current->environments[current->freeIndex]);
+      }
+      else
+      {
+        previous = current;
+      }
+    }
   }
 
-  self->permanentStrings[self->permanentStringsLength] = string;
-  self->permanentStringsLength++;
+  previous->overflow = EnvironmentPool_construct();
+  return EnvironmentPool_allocate(previous->overflow);
 }
 
 Object integerLiteral(int32_t literal)
@@ -172,22 +377,16 @@ Object integerLiteral(int32_t literal)
   return result;
 }
 
-Object stringLiteral(Runtime* runtime, const char* literal)
+Object stringLiteral(const char* literal)
 {
-  String* resultString = malloc(sizeof(String));
-  resultString->length = strlen(literal);
-  resultString->characters = malloc(resultString->length);
-  memcpy(resultString->characters, literal, resultString->length);
-  Runtime_addPermanentString(runtime, resultString);
-
   Object result;
   result.type = STRING;
-  result.instance.string = resultString;
+  result.instance.string = literal;
   return result;
 }
 
 // TODO Make this conditionally added
-Object builtin$negate(Object input)
+Object operator$negate(Object input)
 {
   assert(input.type == INTEGER);
 
@@ -197,64 +396,27 @@ Object builtin$negate(Object input)
   return result;
 }
 
-Object builtin$add(Object left, Object right)
-{
-  assert(left.type == INTEGER);
-  assert(right.type == INTEGER);
-
-  Object result;
-  result.type = INTEGER;
-  result.instance.integer = left.instance.integer + right.instance.integer;
-  return result;
-}
-
-Object builtin$subtract(Object left, Object right)
-{
-  assert(left.type == INTEGER);
-  assert(right.type == INTEGER);
-
-  Object result;
-  result.type = INTEGER;
-  result.instance.integer = left.instance.integer - right.instance.integer;
-  return result;
-}
-
-Object builtin$multiply(Object left, Object right)
+{% for id in infix_declarations %}
+Object operator${{ id.name }}(Object left, Object right)
 {
-  assert(left.type == INTEGER);
-  assert(right.type == INTEGER);
+  assert(left.type == {{ id.in_type.upper() }});
+  assert(right.type == {{ id.in_type.upper() }});
 
   Object result;
-  result.type = INTEGER;
-  result.instance.integer = left.instance.integer * right.instance.integer;
+  result.type = {{ id.out_type.upper() }};
+  result.instance.{{ id.out_type.lower() }} = left.instance.{{ id.in_type.lower() }} {{ id.operator }} right.instance.{{ id.in_type.lower() }};
   return result;
 }
+{% endfor %}
 
-Object builtin$integerDivide(Object left, Object right)
+{% if 'pow' in builtins %}
+Object builtin$pow$implementation(EnvironmentPool* environmentPool, Environment* parent, size_t argc, Object* args)
 {
-  assert(left.type == INTEGER);
-  assert(right.type == INTEGER);
+  assert(argc == 2);
 
-  Object result;
-  result.type = INTEGER;
-  result.instance.integer = left.instance.integer / right.instance.integer;
-  return result;
-}
+  Object base = args[0];
+  Object exponent = args[1];
 
-Object builtin$modularDivide(Object left, Object right)
-{
-  assert(left.type == INTEGER);
-  assert(right.type == INTEGER);
-
-  Object result;
-  result.type = INTEGER;
-  result.instance.integer = left.instance.integer % right.instance.integer;
-  return result;
-}
-
-{% if 'pow' in builtins %}
-Object builtin$pow(Object base, Object exponent)
-{
   assert(base.type == INTEGER);
   assert(exponent.type == INTEGER);
 
@@ -263,39 +425,71 @@ Object builtin$pow(Object base, Object exponent)
   result.instance.integer = pow(base.instance.integer, exponent.instance.integer);
   return result;
 }
+
+Object builtin$pow = { CLOSURE, (Instance)(Closure){ NULL, builtin$pow$implementation } };
 {% endif %}
 
 {% if 'print' in builtins %}
-void builtin$print(Object output)
+Object builtin$print$implementation(EnvironmentPool* environmentPool, Environment* parent, size_t argc, Object* args)
 {
-  switch(output.type)
+  for(size_t i = 0; i < argc; i++)
   {
-    case INTEGER:
-      printf("%" PRId32, output.instance.integer);
-      break;
-
-    case STRING:
-      // Using fwrite instead of printf to handle size_t length
-      fwrite(output.instance.string->characters, 1, output.instance.string->length, stdout);
-      break;
-
-    default:
-      assert(false);
+    Object output = args[i];
+    switch(output.type)
+    {
+      case BOOLEAN:
+        fputs(output.instance.boolean ? "true" : "false", stdout);
+        break;
+
+      case CLOSURE:
+        // TODO Print something better
+        printf("<Closure>");
+        break;
+
+      case INTEGER:
+        printf("%" PRId32, output.instance.integer);
+        break;
+
+      case STRING:
+        // Using fwrite instead of printf to handle size_t length
+        printf("%s", output.instance.string);
+        break;
+
+      case VOID:
+        printf("nil");
+        break;
+
+      default:
+        assert(false);
+    }
   }
+
+  // TODO Return something better
+  return builtin$false;
 }
+
+Object builtin$print = { CLOSURE, (Instance)(Closure){ NULL, builtin$print$implementation } };
 {% endif %}
+{% for function_definition in function_definition_list %}
+{{ function_definition }}
+{% endfor %}
 
 int main(int argc, char** argv)
 {
-  Runtime* runtime = Runtime_construct();
-  Environment* environment = Environment_construct();
+  EnvironmentPool* environmentPool = EnvironmentPool_construct();
+  Environment* environment = EnvironmentPool_allocate(environmentPool);
+  Environment_initialize(environment, NULL);
+
+  // TODO Use the symbol from SYMBOL_LIST
+  {% for builtin in builtins %}
+  Environment_set(environment, "{{ builtin }}", builtin${{ builtin }});
+  {% endfor %}
 
   {% for statement in statements %}
   {{ statement }}
   {% endfor %}
 
-  Environment_destruct(environment);
-  Runtime_destruct(runtime);
-
+  Environment_setLive(environment, false);
+  EnvironmentPool_destruct(environmentPool);
   return 0;
 }