X-Git-Url: https://code.kerkeslager.com/?a=blobdiff_plain;f=templates%2Fprogram.c;h=2a08f397bbe4762480dd08a1941b051d6447265e;hb=d6af7d074bf65e782e42055623a197863b5f8000;hp=3d1507610b288f2db08d78c79e1a4a5f83925b9f;hpb=4ba4fcfbb2712a22a9f3211182c9ec6cee9dd0f8;p=fur

diff --git a/templates/program.c b/templates/program.c
index 3d15076..2a08f39 100644
--- a/templates/program.c
+++ b/templates/program.c
@@ -1,18 +1,454 @@
+#include <assert.h>
+#include <inttypes.h>
+#include <stdbool.h>
+#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}}>
+#include <{{standard_library}}>
+{% endfor %}
+
+enum Type;
+typedef enum Type Type;
+union Instance;
+typedef union Instance Instance;
+struct Object;
+typedef struct Object Object;
+struct EnvironmentNode;
+typedef struct EnvironmentNode EnvironmentNode;
+struct Environment;
+typedef struct Environment Environment;
+struct EnvironmentPool;
+typedef struct EnvironmentPool EnvironmentPool;
+
+const char* const STRING_LITERAL_LIST[] = {
+{% for string_literal in string_literal_list %}
+  "{{ string_literal }}",
+{% endfor %}
+};
+
+const char* const SYMBOL_LIST[] = {
+{% for symbol in symbol_list %}
+  "{{ symbol }}",
+{% endfor %}
+};
+
+enum Type
+{
+  BOOLEAN,
+  CLOSURE,
+  INTEGER,
+  STRING
+};
+
+struct Closure;
+typedef struct Closure Closure;
+struct Closure
+{
+  Environment* closed;
+  Object (*call)(EnvironmentPool*, Environment*, size_t, Object*);
+};
+
+union Instance
+{
+  bool boolean;
+  Closure closure;
+  int32_t integer;
+  const char* string;
+};
+
+struct Object
+{
+  Type type;
+  Instance instance;
+};
+
+const Object TRUE = {
+  BOOLEAN,
+  { true }
+};
+
+const Object FALSE = {
+  BOOLEAN,
+  { false }
+};
+
+struct EnvironmentNode
+{
+  const char* key;
+  Object value;
+  EnvironmentNode* next;
+};
+
+struct Environment
+{
+  bool mark;
+  bool live;
+
+  Environment* parent;
+  EnvironmentNode* root;
+};
+
+void Environment_initialize(Environment* self, Environment* parent)
+{
+  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_deinitialize(Environment* self)
+{
+  EnvironmentNode* next;
+  for(EnvironmentNode* node = self->root; node != NULL; node = next)
+  {
+    next = node->next;
+    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:
+        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)
+{
+  EnvironmentNode* node = malloc(sizeof(EnvironmentNode));
+  node->key = key;
+  node->value = value;
+  node->next = self->root;
+  self->root = node;
+}
+
+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 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);
+}
+
+# define POOL_SIZE 64
+struct EnvironmentPool
+{
+  int8_t freeIndex;
+  bool allocatedFlags[POOL_SIZE];
+  Environment environments[POOL_SIZE];
+  EnvironmentPool* overflow;
+};
+
+EnvironmentPool* EnvironmentPool_construct();
+void EnvironmentPool_initialize(EnvironmentPool*);
+void EnvironmentPool_deinitialize(EnvironmentPool*);
+void EnvironmentPool_destruct(EnvironmentPool*);
+
+EnvironmentPool* EnvironmentPool_construct()
+{
+  EnvironmentPool* result = malloc(sizeof(EnvironmentPool));
+  EnvironmentPool_initialize(result);
+  return result;
+}
+
+void EnvironmentPool_initialize(EnvironmentPool* self)
+{
+  self->overflow = NULL;
+  self->freeIndex = 0;
+
+  for(size_t i = 0; i < POOL_SIZE; i++)
+  {
+    self->allocatedFlags[i] = false;
+    self->environments[i].live = false;
+  }
+}
+
+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 EnvironmentPool_GC(EnvironmentPool* self)
+{
+  // Unmark all the environments
+  for(EnvironmentPool* current = self; current != NULL; current = current->overflow)
+  {
+    for(int8_t i = 0; i < POOL_SIZE; i++)
+    {
+      current->environments[i].mark = false;
+    }
+  }
+
+  // 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++)
+    {
+      if(current->environments[i].live)
+      {
+        Environment_mark(&(current->environments[i]));
+      }
+    }
+  }
+
+  // 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;
+      }
+    }
+  }
+}
+
+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;
+      }
+    }
+  }
+
+  previous->overflow = EnvironmentPool_construct();
+  return EnvironmentPool_allocate(previous->overflow);
+}
+
+Object integerLiteral(int32_t literal)
+{
+  Object result;
+  result.type = INTEGER;
+  result.instance.integer = literal;
+  return result;
+}
+
+Object stringLiteral(const char* literal)
+{
+  Object result;
+  result.type = STRING;
+  result.instance.string = literal;
+  return result;
+}
+
+// TODO Make this conditionally added
+Object operator$negate(Object input)
+{
+  assert(input.type == INTEGER);
+
+  Object result;
+  result.type = INTEGER;
+  result.instance.integer = -input.instance.integer;
+  return result;
+}
+
+{% for id in infix_declarations %}
+Object operator${{ id.name }}(Object left, Object right)
+{
+  assert(left.type == {{ id.in_type.upper() }});
+  assert(right.type == {{ id.in_type.upper() }});
+
+  Object result;
+  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 %}
 
+{% if 'pow' in builtins %}
+Object builtin$pow$implementation(EnvironmentPool* environmentPool, Environment* parent, size_t argc, Object* args)
+{
+  assert(argc == 2);
+
+  Object base = args[0];
+  Object exponent = args[1];
+
+  assert(base.type == INTEGER);
+  assert(exponent.type == INTEGER);
+
+  Object result;
+  result.type = INTEGER;
+  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(const char* output)
+Object builtin$print$implementation(EnvironmentPool* environmentPool, Environment* parent, size_t argc, Object* args)
 {
-  printf("%s\n", output);
+  for(size_t i = 0; i < argc; i++)
+  {
+    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;
+
+      default:
+        assert(false);
+    }
+  }
+
+  // TODO Return something better
+  return FALSE;
 }
+
+Object builtin$print = { CLOSURE, (Instance)(Closure){ NULL, builtin$print$implementation } };
 {% endif %}
 
+{% for function_definition in function_definition_list %}
+Object user${{function_definition.name}}$implementation(EnvironmentPool* environmentPool, Environment* parent, size_t argc, Object* args)
+{
+  assert(argc == {{ function_definition.argument_name_list|length }});
+
+  Environment* environment = EnvironmentPool_allocate(environmentPool);
+  Environment_initialize(environment, parent);
+
+  {% for argument_name in function_definition.argument_name_list %}
+  Environment_set(environment, "{{ argument_name }}", args[{{ loop.index0 }}]);
+  {% endfor %}
+
+  {% for statement in function_definition.statement_list[:-1] %}
+  {{ generate_statement(statement) }}
+  {% endfor %}
+
+  Object result = {{ generate_statement(function_definition.statement_list[-1]) }}
+
+  Environment_setLive(environment, false);
+  return result;
+}
+
+{% endfor %}
 int main(int argc, char** argv)
 {
+  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 }}
+  {{ generate_statement(statement) }}
   {% endfor %}
+
+  Environment_setLive(environment, false);
+  EnvironmentPool_destruct(environmentPool);
   return 0;
 }