codegen/valaccodeassignmentmodule.vala

   1 /* valaccodeassignmentmodule.vala
   2  *
   3  * Copyright (C) 2006-2009  Jürg Billeter
   4  * Copyright (C) 2006-2008  Raffaele Sandrini
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
  19  *
  20  * Author:
  21  *      Jürg Billeter <j@bitron.ch>
  22  *      Raffaele Sandrini <raffaele@sandrini.ch>
  23  */
  24
  25 using GLib;
  26 using Gee;
  27
  28 /**
  29  * The link between an assignment and generated code.
  30  */
  31 internal class Vala.CCodeAssignmentModule : CCodeMemberAccessModule {
  32         public CCodeAssignmentModule (CCodeGenerator codegen, CCodeModule? next) {
  33                 base (codegen, next);
  34         }
  35
  36         CCodeExpression emit_property_assignment (Assignment assignment) {
  37                 var ma = assignment.left as MemberAccess;
  38
  39                 var prop = (Property) assignment.left.symbol_reference;
  40
  41                 if (!(prop is DynamicProperty)) {
  42                         generate_property_accessor_declaration (prop.set_accessor, source_declarations);
  43
  44                         if (!prop.external && prop.external_package) {
  45                                 // internal VAPI properties
  46                                 // only add them once per source file
  47                                 if (add_generated_external_symbol (prop)) {
  48                                         visit_property (prop);
  49                                 }
  50                         }
  51                 }
  52
  53                 if (prop.set_accessor.construction && current_type_symbol is Class && current_class.is_subtype_of (gobject_type) && in_creation_method) {
  54                         return head.get_construct_property_assignment (prop.get_canonical_cconstant (), prop.property_type, (CCodeExpression) assignment.right.ccodenode);
  55                 } else {
  56                         CCodeExpression cexpr = (CCodeExpression) assignment.right.ccodenode;
  57
  58                         if (!prop.no_accessor_method) {
  59                                 if (prop.property_type.is_real_struct_type ()) {
  60                                         cexpr = get_address_of_expression (assignment.right, cexpr);
  61                                 }
  62                         }
  63
  64                         if (assignment.operator != AssignmentOperator.SIMPLE) {
  65                                 CCodeBinaryOperator cop;
  66                                 if (assignment.operator == AssignmentOperator.BITWISE_OR) {
  67                                         cop = CCodeBinaryOperator.BITWISE_OR;
  68                                 } else if (assignment.operator == AssignmentOperator.BITWISE_AND) {
  69                                         cop = CCodeBinaryOperator.BITWISE_AND;
  70                                 } else if (assignment.operator == AssignmentOperator.BITWISE_XOR) {
  71                                         cop = CCodeBinaryOperator.BITWISE_XOR;
  72                                 } else if (assignment.operator == AssignmentOperator.ADD) {
  73                                         cop = CCodeBinaryOperator.PLUS;
  74                                 } else if (assignment.operator == AssignmentOperator.SUB) {
  75                                         cop = CCodeBinaryOperator.MINUS;
  76                                 } else if (assignment.operator == AssignmentOperator.MUL) {
  77                                         cop = CCodeBinaryOperator.MUL;
  78                                 } else if (assignment.operator == AssignmentOperator.DIV) {
  79                                         cop = CCodeBinaryOperator.DIV;
  80                                 } else if (assignment.operator == AssignmentOperator.PERCENT) {
  81                                         cop = CCodeBinaryOperator.MOD;
  82                                 } else if (assignment.operator == AssignmentOperator.SHIFT_LEFT) {
  83                                         cop = CCodeBinaryOperator.SHIFT_LEFT;
  84                                 } else if (assignment.operator == AssignmentOperator.SHIFT_RIGHT) {
  85                                         cop = CCodeBinaryOperator.SHIFT_RIGHT;
  86                                 } else {
  87                                         assert_not_reached ();
  88                                 }
  89                                 cexpr = new CCodeBinaryExpression (cop, (CCodeExpression) get_ccodenode (assignment.left), cexpr);
  90                         }
  91
  92                         var ccall = get_property_set_call (prop, ma, cexpr, assignment.right);
  93
  94                         // assignments are expressions, so return the current property value, except if we're sure that it can't be used
  95                         if (!(assignment.parent_node is ExpressionStatement)) {
  96                                 var ccomma = new CCodeCommaExpression ();
  97                                 ccomma.append_expression (ccall); // update property
  98                                 ccomma.append_expression ((CCodeExpression) get_ccodenode (ma)); // current property value
  99
 100                                 return ccomma;
 101                         } else {
 102                                 return ccall;
 103                         }
 104                 }
 105         }
 106
 107         CCodeExpression emit_simple_assignment (Assignment assignment) {
 108                 CCodeExpression rhs = (CCodeExpression) assignment.right.ccodenode;
 109                 CCodeExpression lhs = (CCodeExpression) get_ccodenode (assignment.left);
 110                 CCodeCommaExpression outer_ccomma = null;
 111
 112                 bool unref_old = requires_destroy (assignment.left.value_type);
 113                 bool array = false;
 114                 bool instance_delegate = false;
 115                 if (assignment.left.value_type is ArrayType) {
 116                         var array_field = assignment.left.symbol_reference as Field;
 117                         array = (array_field == null || !array_field.no_array_length);
 118                 } else if (assignment.left.value_type is DelegateType) {
 119                         var delegate_type = (DelegateType) assignment.left.value_type;
 120                         if (delegate_type.delegate_symbol.has_target) {
 121                                 var delegate_field = assignment.left.symbol_reference as Field;
 122                                 if (delegate_field == null || !delegate_field.no_delegate_target) {
 123                                         instance_delegate = true;
 124                                 }
 125                         }
 126                 }
 127
 128                 if (unref_old || array || instance_delegate) {
 129                         var ccomma = new CCodeCommaExpression ();
 130
 131                         if (!is_pure_ccode_expression (lhs)) {
 132                                 /* Assign lhs to temp var to avoid repeating side effect */
 133                                 outer_ccomma = new CCodeCommaExpression ();
 134
 135                                 var lhs_value_type = assignment.left.value_type.copy ();
 136                                 string lhs_temp_name = "_tmp%d_".printf (next_temp_var_id++);
 137                                 var lhs_temp = new LocalVariable (lhs_value_type, "*" + lhs_temp_name);
 138                                 temp_vars.insert (0, lhs_temp);
 139                                 outer_ccomma.append_expression (new CCodeAssignment (get_variable_cexpression (lhs_temp_name), new CCodeUnaryExpression (CCodeUnaryOperator.ADDRESS_OF, lhs)));
 140                                 lhs = new CCodeParenthesizedExpression (new CCodeUnaryExpression (CCodeUnaryOperator.POINTER_INDIRECTION, get_variable_cexpression (lhs_temp_name)));
 141                         }
 142
 143                         var temp_decl = get_temp_variable (assignment.left.value_type);
 144                         temp_vars.insert (0, temp_decl);
 145                         ccomma.append_expression (new CCodeAssignment (get_variable_cexpression (temp_decl.name), rhs));
 146                         if (unref_old) {
 147                                 /* unref old value */
 148                                 ccomma.append_expression (get_unref_expression (lhs, assignment.left.value_type, assignment.left));
 149                         }
 150
 151                         if (array) {
 152                                 var array_type = (ArrayType) assignment.left.value_type;
 153                                 for (int dim = 1; dim <= array_type.rank; dim++) {
 154                                         var lhs_array_len = head.get_array_length_cexpression (assignment.left, dim);
 155                                         var rhs_array_len = head.get_array_length_cexpression (assignment.right, dim);
 156                                         ccomma.append_expression (new CCodeAssignment (lhs_array_len, rhs_array_len));
 157                                 }
 158                                 if (array_type.rank == 1) {
 159                                         var array_var = assignment.left.symbol_reference;
 160                                         if (array_var != null && array_var.is_internal_symbol ()
 161                                             && (array_var is LocalVariable || array_var is Field)) {
 162                                                 var lhs_array_size = head.get_array_size_cexpression (assignment.left);
 163                                                 var rhs_array_len = head.get_array_length_cexpression (assignment.left, 1);
 164                                                 ccomma.append_expression (new CCodeAssignment (lhs_array_size, rhs_array_len));
 165                                         }
 166                                 }
 167                         } else if (instance_delegate) {
 168                                 var lhs_delegate_target = get_delegate_target_cexpression (assignment.left);
 169                                 var rhs_delegate_target = get_delegate_target_cexpression (assignment.right);
 170                                 ccomma.append_expression (new CCodeAssignment (lhs_delegate_target, rhs_delegate_target));
 171                         }
 172
 173                         ccomma.append_expression (get_variable_cexpression (temp_decl.name));
 174
 175                         rhs = ccomma;
 176                 }
 177
 178                 var cop = CCodeAssignmentOperator.SIMPLE;
 179                 if (assignment.operator == AssignmentOperator.BITWISE_OR) {
 180                         cop = CCodeAssignmentOperator.BITWISE_OR;
 181                 } else if (assignment.operator == AssignmentOperator.BITWISE_AND) {
 182                         cop = CCodeAssignmentOperator.BITWISE_AND;
 183                 } else if (assignment.operator == AssignmentOperator.BITWISE_XOR) {
 184                         cop = CCodeAssignmentOperator.BITWISE_XOR;
 185                 } else if (assignment.operator == AssignmentOperator.ADD) {
 186                         cop = CCodeAssignmentOperator.ADD;
 187                 } else if (assignment.operator == AssignmentOperator.SUB) {
 188                         cop = CCodeAssignmentOperator.SUB;
 189                 } else if (assignment.operator == AssignmentOperator.MUL) {
 190                         cop = CCodeAssignmentOperator.MUL;
 191                 } else if (assignment.operator == AssignmentOperator.DIV) {
 192                         cop = CCodeAssignmentOperator.DIV;
 193                 } else if (assignment.operator == AssignmentOperator.PERCENT) {
 194                         cop = CCodeAssignmentOperator.PERCENT;
 195                 } else if (assignment.operator == AssignmentOperator.SHIFT_LEFT) {
 196                         cop = CCodeAssignmentOperator.SHIFT_LEFT;
 197                 } else if (assignment.operator == AssignmentOperator.SHIFT_RIGHT) {
 198                         cop = CCodeAssignmentOperator.SHIFT_RIGHT;
 199                 }
 200
 201                 CCodeExpression codenode = new CCodeAssignment (lhs, rhs, cop);
 202
 203                 if (outer_ccomma != null) {
 204                         outer_ccomma.append_expression (codenode);
 205                         codenode = outer_ccomma;
 206                 }
 207
 208                 return codenode;
 209         }
 210
 211         CCodeExpression emit_fixed_length_array_assignment (Assignment assignment, ArrayType array_type) {
 212                 CCodeExpression rhs = (CCodeExpression) assignment.right.ccodenode;
 213                 CCodeExpression lhs = (CCodeExpression) get_ccodenode (assignment.left);
 214
 215                 source_declarations.add_include ("string.h");
 216
 217                 // it is necessary to use memcpy for fixed-length (stack-allocated) arrays
 218                 // simple assignments do not work in C
 219                 var sizeof_call = new CCodeFunctionCall (new CCodeIdentifier ("sizeof"));
 220                 sizeof_call.add_argument (new CCodeIdentifier (array_type.element_type.get_cname ()));
 221                 var size = new CCodeBinaryExpression (CCodeBinaryOperator.MUL, new CCodeConstant ("%d".printf (array_type.length)), sizeof_call);
 222                 var ccopy = new CCodeFunctionCall (new CCodeIdentifier ("memcpy"));
 223                 ccopy.add_argument (lhs);
 224                 ccopy.add_argument (rhs);
 225                 ccopy.add_argument (size);
 226
 227                 return ccopy;
 228         }
 229
 230         public override void visit_assignment (Assignment assignment) {
 231                 assignment.right.accept (codegen);
 232
 233                 if (assignment.left.error || assignment.right.error) {
 234                         assignment.error = true;
 235                         return;
 236                 }
 237
 238                 if (assignment.left.symbol_reference is Property) {
 239                         assignment.ccodenode = emit_property_assignment (assignment);
 240                 } else {
 241                         var array_type = assignment.left.value_type as ArrayType;
 242                         if (array_type != null && array_type.fixed_length) {
 243                                 assignment.ccodenode = emit_fixed_length_array_assignment (assignment, array_type);
 244                         } else {
 245                                 assignment.ccodenode = emit_simple_assignment (assignment);
 246                         }
 247                 }
 248         }
 249 }