Finish AST => BC structures conv. for subtask1

src/bc_compiler.c

@@ -57,6 +57,26 @@ u16 get_string_index ( BCCompilerState * state, Str str ) {
   return i;
 }
+u16 get_local_index ( BCCompilerState * state, Str name ) {
+  BCFunction * function = & state -> constants . constants [ state -> fp ];
+  LocalScope * scope = state -> scope;
+  size_t i;
+  while ( scope ) {
+    for ( i = 0; i < scope -> used_locals; ++i )
+      if ( str_eq ( scope -> locals [ i ], name ) )
+        return function -> parameters + ( scope -> prev ? scope -> prev -> local_count + i );
+    scope = scope -> prev;
+  }
+  u32 * n = state -> scope -> local_count;
+  assert ( *n != 256 * 256 );
+  state -> scope -> locals [ *n ] = name;
+  ++(*n);
+  ++(state -> scope -> used_locals);
+  if ( *n > function -> locals )
+    function -> locals = *n;
+  return *n - 1 + function -> parameters; 
+}
+
 void gen_bc_constant ( BCCompilerState * state, u16 index ) {
   BCFunction * function = & state -> constants . constants [ state -> fp ];
   string_write_byte ( function -> bc, 0x01 );
@@ -176,6 +196,63 @@ void ast_to_bc ( BCCompilerState * state, Ast * ast ) {
       string_write_byte ( & function -> bc, print -> argument_cnt & 255 );
       return;      
     }
+    case AST_DEFINITION: {
+      AstDefinition * def = (AstDefinition*) ast;
+      ast_to_bc ( state, def -> value );
+      if ( ! state -> scope -> prev ) {
+        // GLOBAL
+        u16 index = get_string_index ( state, def -> name );
+        BCFunction * function = & state -> constants . constants [ state -> fp ];
+        string_write_byte ( & function -> bc, 0x0B );
+        string_write_u16 ( & function -> bc, index );
+      } else {
+        // LOCAL
+        u16 index = get_local_index ( state, def -> name );
+        BCFunction * function = & state -> constants . constants [ state -> fp ];
+        string_write_byte ( & function -> bc, 0x09 );
+        string_write_u16 ( & function -> bc, index );
+      }
+      return;
+    }
+    case AST_VARIABLE_ACCESS: {
+      AstVariableAccess * var = (AstVariableAccess*) ast;
+      if ( ! state -> scope -> prev ) {
+        // GLOBAL
+        u16 index = get_string_index ( state, var -> name );
+        BCFunction * function = & state -> constants . constants [ state -> fp ];
+        string_write_byte ( & function -> bc, 0x0C );
+        string_write_u16 ( & function -> bc, index );
+      } else {
+        // LOCAL
+        u16 index = get_local_index ( state, var -> name );
+        BCFunction * function = & state -> constants . constants [ state -> fp ];
+        string_write_byte ( & function -> bc, 0x0A );
+        string_write_u16 ( & function -> bc, index );
+      }
+      return;
+    }
+    case AST_VARIABLE_ASSIGNMENT: {
+      AstVariableAssignment * assign = (AstVariableAssignment*) ast;
+      ast_to_bc ( state, assign -> value );
+      if ( ! state -> scope -> prev ) {
+        // GLOBAL
+        u16 constants = state -> constants . constant_count; 
+        u16 index = get_string_index ( state, assign -> name );
+        assert ( constants == state -> constants . constant_count );
+        BCFunction * function = & state -> constants . constants [ state -> fp ];
+        string_write_byte ( & function -> bc, 0x0B );
+        string_write_u16 ( & function -> bc, index );
+      } else {
+        // LOCAL
+        u16 locals = state -> scope -> local_count;
+        u16 index = get_local_index ( state, assign -> name );
+        assert ( locals == state -> scope -> local_count );
+        BCFunction * function = & state -> constants . constants [ state -> fp ];
+        string_write_byte ( & function -> bc, 0x09 );
+        string_write_u16 ( & function -> bc, index );
+      }
+      return;
+    }
     default:
       assert ( false );
   }

src/bc_compiler.h

@@ -55,8 +55,8 @@ typedef struct Globals {
 typedef struct LocalScope {
   struct LocalScope * prev;
-  u16 used_locals;
-  u32 local_count;
+  u16 used_locals; // locals at use in this scope
+  u16 local_count; // locals at use at this time
   Str locals [];
 } LocalScope;
@@ -72,6 +72,7 @@ BCConstant create_function ( Str name, u8 parameters );
 LocalScope * create_function_scope ( u8 parameters );
 u16 get_string_index ( BCCompilerState * state, Str str );
+u16 get_local_index  ( BCCompilerState * state, Str name );
 void gen_bc_constant ( BCCompilerState * state, u16 index );
 void insert_constant ( BCCompilerState * state, Constant constant );