1  /* Usage example for libgccjit.so
       2     Copyright (C) 2014-2023 Free Software Foundation, Inc.
       3  
       4  This file is part of GCC.
       5  
       6  GCC is free software; you can redistribute it and/or modify it
       7  under the terms of the GNU General Public License as published by
       8  the Free Software Foundation; either version 3, or (at your option)
       9  any later version.
      10  
      11  GCC is distributed in the hope that it will be useful, but
      12  WITHOUT ANY WARRANTY; without even the implied warranty of
      13  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      14  General Public License for more details.
      15  
      16  You should have received a copy of the GNU General Public License
      17  along with GCC; see the file COPYING3.  If not see
      18  <http://www.gnu.org/licenses/>.  */
      19  
      20  #include <libgccjit.h>
      21  
      22  #include <stdlib.h>
      23  #include <stdio.h>
      24  
      25  void
      26  create_code (gcc_jit_context *ctxt)
      27  {
      28    /* Let's try to inject the equivalent of:
      29  
      30        int square (int i)
      31        {
      32          return i * i;
      33        }
      34    */
      35    gcc_jit_type *int_type =
      36      gcc_jit_context_get_type (ctxt, GCC_JIT_TYPE_INT);
      37    gcc_jit_param *param_i =
      38      gcc_jit_context_new_param (ctxt, NULL, int_type, "i");
      39    gcc_jit_function *func =
      40      gcc_jit_context_new_function (ctxt, NULL,
      41                                    GCC_JIT_FUNCTION_EXPORTED,
      42                                    int_type,
      43                                    "square",
      44                                    1, &param_i,
      45                                    0);
      46  
      47    gcc_jit_block *block = gcc_jit_function_new_block (func, NULL);
      48  
      49    gcc_jit_rvalue *expr =
      50      gcc_jit_context_new_binary_op (
      51        ctxt, NULL,
      52        GCC_JIT_BINARY_OP_MULT, int_type,
      53        gcc_jit_param_as_rvalue (param_i),
      54        gcc_jit_param_as_rvalue (param_i));
      55  
      56     gcc_jit_block_end_with_return (block, NULL, expr);
      57  }
      58  
      59  int
      60  main (int argc, char **argv)
      61  {
      62    gcc_jit_context *ctxt = NULL;
      63    gcc_jit_result *result = NULL;
      64  
      65    /* Get a "context" object for working with the library.  */
      66    ctxt = gcc_jit_context_acquire ();
      67    if (!ctxt)
      68      {
      69        fprintf (stderr, "NULL ctxt");
      70        goto error;
      71      }
      72  
      73    /* Set some options on the context.
      74       Let's see the code being generated, in assembler form.  */
      75    gcc_jit_context_set_bool_option (
      76      ctxt,
      77      GCC_JIT_BOOL_OPTION_DUMP_GENERATED_CODE,
      78      0);
      79  
      80    /* Populate the context.  */
      81    create_code (ctxt);
      82  
      83    /* Compile the code.  */
      84    result = gcc_jit_context_compile (ctxt);
      85    if (!result)
      86      {
      87        fprintf (stderr, "NULL result");
      88        goto error;
      89      }
      90  
      91    /* We're done with the context; we can release it: */
      92    gcc_jit_context_release (ctxt);
      93    ctxt = NULL;
      94  
      95    /* Extract the generated code from "result".  */
      96    void *fn_ptr = gcc_jit_result_get_code (result, "square");
      97    if (!fn_ptr)
      98       {
      99         fprintf (stderr, "NULL fn_ptr");
     100         goto error;
     101       }
     102  
     103    typedef int (*fn_type) (int);
     104    fn_type square = (fn_type)fn_ptr;
     105    printf ("result: %d\n", square (5));
     106  
     107   error:
     108    if (ctxt)
     109      gcc_jit_context_release (ctxt);
     110    if (result)
     111      gcc_jit_result_release (result);
     112    return 0;
     113  }