/*
 * Renjin : JVM-based interpreter for the R language for the statistical analysis
 * Copyright Â© 2010-2019 BeDataDriven Groep B.V. and contributors
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, a copy is available at
 * https://www.gnu.org/licenses/gpl-2.0.txt
 */
package org.renjin.gcc.codegen.call;

import org.renjin.gcc.codegen.MethodGenerator;
import org.renjin.gcc.codegen.expr.ExprFactory;
import org.renjin.gcc.codegen.expr.GExpr;
import org.renjin.gcc.codegen.expr.JExpr;
import org.renjin.gcc.codegen.type.TypeOracle;
import org.renjin.gcc.codegen.type.fun.FunctionRefGenerator;
import org.renjin.gcc.gimple.statement.GimpleCall;
import org.renjin.gcc.gimple.type.GimpleType;
import org.renjin.gcc.runtime.MixedPtr;
import org.renjin.repackaged.asm.Handle;
import org.renjin.repackaged.asm.Opcodes;
import org.renjin.repackaged.asm.Type;

/**
 * Generates function calls to {@code malloc()}
 */
public class MallocCallGenerator implements CallGenerator, MethodHandleGenerator {
  
  private TypeOracle typeOracle;

  public MallocCallGenerator(TypeOracle typeOracle) {
    this.typeOracle = typeOracle;
  }

  @Override
  public void emitCall(MethodGenerator mv, ExprFactory exprFactory, GimpleCall call) {
    // Obviously if we're not assigning this, it's a NO-OP
    if(call.getLhs() == null) {
      return;
    }

    // Generate the malloc for the given type
    GimpleType pointerType = call.getLhs().getType();
    
    // Find the size to allocate
    JExpr size = exprFactory.findPrimitiveGenerator(call.getOperands().get(0));
    
    GExpr mallocGenerator = typeOracle.forPointerType(pointerType).malloc(mv, size);
    GExpr lhs = exprFactory.findGenerator(call.getLhs());
    lhs.store(mv, mallocGenerator);
  }

  @Override
  public JExpr getMethodHandle() {
    return new FunctionRefGenerator(new Handle(Opcodes.H_INVOKESTATIC,
        Type.getInternalName(MixedPtr.class), "malloc",
        Type.getMethodDescriptor(Type.getType(MixedPtr.class), Type.INT_TYPE)));
  }
}
