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tut01-hello-world.c revision 1.1.1.5 
      1 /* Smoketest example for libgccjit.so
      2    Copyright (C) 2014-2019 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 static void
     26 create_code (gcc_jit_context *ctxt)
     27 {
     28   /* Let's try to inject the equivalent of:
     29      void
     30      greet (const char *name)
     31      {
     32         printf ("hello %s\n", name);
     33      }
     34   */
     35   gcc_jit_type *void_type =
     36     gcc_jit_context_get_type (ctxt, GCC_JIT_TYPE_VOID);
     37   gcc_jit_type *const_char_ptr_type =
     38     gcc_jit_context_get_type (ctxt, GCC_JIT_TYPE_CONST_CHAR_PTR);
     39   gcc_jit_param *param_name =
     40     gcc_jit_context_new_param (ctxt, NULL, const_char_ptr_type, "name");
     41   gcc_jit_function *func =
     42     gcc_jit_context_new_function (ctxt, NULL,
     43                                   GCC_JIT_FUNCTION_EXPORTED,
     44                                   void_type,
     45                                   "greet",
     46                                   1, &param_name,
     47                                   0);
     48 
     49   gcc_jit_param *param_format =
     50     gcc_jit_context_new_param (ctxt, NULL, const_char_ptr_type, "format");
     51   gcc_jit_function *printf_func =
     52     gcc_jit_context_new_function (ctxt, NULL,
     53 				  GCC_JIT_FUNCTION_IMPORTED,
     54 				  gcc_jit_context_get_type (
     55 				     ctxt, GCC_JIT_TYPE_INT),
     56 				  "printf",
     57 				  1, &param_format,
     58 				  1);
     59   gcc_jit_rvalue *args[2];
     60   args[0] = gcc_jit_context_new_string_literal (ctxt, "hello %s\n");
     61   args[1] = gcc_jit_param_as_rvalue (param_name);
     62 
     63   gcc_jit_block *block = gcc_jit_function_new_block (func, NULL);
     64 
     65   gcc_jit_block_add_eval (
     66     block, NULL,
     67     gcc_jit_context_new_call (ctxt,
     68                               NULL,
     69                               printf_func,
     70                               2, args));
     71   gcc_jit_block_end_with_void_return (block, NULL);
     72 }
     73 
     74 int
     75 main (int argc, char **argv)
     76 {
     77   gcc_jit_context *ctxt;
     78   gcc_jit_result *result;
     79 
     80   /* Get a "context" object for working with the library.  */
     81   ctxt = gcc_jit_context_acquire ();
     82   if (!ctxt)
     83     {
     84       fprintf (stderr, "NULL ctxt");
     85       exit (1);
     86     }
     87 
     88   /* Set some options on the context.
     89      Let's see the code being generated, in assembler form.  */
     90   gcc_jit_context_set_bool_option (
     91     ctxt,
     92     GCC_JIT_BOOL_OPTION_DUMP_GENERATED_CODE,
     93     0);
     94 
     95   /* Populate the context.  */
     96   create_code (ctxt);
     97 
     98   /* Compile the code.  */
     99   result = gcc_jit_context_compile (ctxt);
    100   if (!result)
    101     {
    102       fprintf (stderr, "NULL result");
    103       exit (1);
    104     }
    105 
    106   /* Extract the generated code from "result".  */
    107   typedef void (*fn_type) (const char *);
    108   fn_type greet =
    109     (fn_type)gcc_jit_result_get_code (result, "greet");
    110   if (!greet)
    111     {
    112       fprintf (stderr, "NULL greet");
    113       exit (1);
    114     }
    115 
    116   /* Now call the generated function: */
    117   greet ("world");
    118   fflush (stdout);
    119 
    120   gcc_jit_context_release (ctxt);
    121   gcc_jit_result_release (result);
    122   return 0;
    123 }
    124