/* Subroutines for the gcc driver.
   Copyright (C) 2011-2015 Free Software Foundation, Inc.

This file is part of GCC.

GCC 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 3, or (at your option)
any later version.

GCC 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 GCC; see the file COPYING3.  If not see
<http://www.gnu.org/licenses/>.  */

#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "configargs.h"

struct vendor_cpu {
  const char *part_no;
  const char *arch_name;
  const char *cpu_name;
};

static struct vendor_cpu arm_cpu_table[] = {
    {"0x926", "armv5te", "arm926ej-s"},
    {"0xa26", "armv5te", "arm1026ej-s"},
    {"0xb02", "armv6k", "mpcore"},
    {"0xb36", "armv6j", "arm1136j-s"},
    {"0xb56", "armv6t2", "arm1156t2-s"},
    {"0xb76", "armv6zk", "arm1176jz-s"},
    {"0xc05", "armv7-a", "cortex-a5"},
    {"0xc07", "armv7ve", "cortex-a7"},
    {"0xc08", "armv7-a", "cortex-a8"},
    {"0xc09", "armv7-a", "cortex-a9"},
    {"0xc0d", "armv7ve", "cortex-a12"},
    {"0xc0e", "armv7ve", "cortex-a17"},
    {"0xc0f", "armv7ve", "cortex-a15"},
    {"0xc14", "armv7-r", "cortex-r4"},
    {"0xc15", "armv7-r", "cortex-r5"},
    {"0xc20", "armv6-m", "cortex-m0"},
    {"0xc21", "armv6-m", "cortex-m1"},
    {"0xc23", "armv7-m", "cortex-m3"},
    {"0xc24", "armv7e-m", "cortex-m4"},
    {NULL, NULL, NULL}
};

static struct {
  const char *vendor_no;
  const struct vendor_cpu *vendor_parts;
} vendors[] = {
    {"0x41", arm_cpu_table},
    {NULL, NULL}
};

/* This will be called by the spec parser in gcc.c when it sees
   a %:local_cpu_detect(args) construct.  Currently it will be called
   with either "arch", "cpu" or "tune" as argument depending on if
   -march=native, -mcpu=native or -mtune=native is to be substituted.

   It returns a string containing new command line parameters to be
   put at the place of the above two options, depending on what CPU
   this is executed.  E.g. "-march=armv7-a" on a Cortex-A8 for
   -march=native.  If the routine can't detect a known processor,
   the -march or -mtune option is discarded.

   ARGC and ARGV are set depending on the actual arguments given
   in the spec.  */
const char *
host_detect_local_cpu (int argc, const char **argv)
{
  const char *val = NULL;
  char buf[128];
  FILE *f = NULL;
  bool arch;
  const struct vendor_cpu *cpu_table = NULL;

  if (argc < 1)
    goto not_found;

  arch = strcmp (argv[0], "arch") == 0;
  if (!arch && strcmp (argv[0], "cpu") != 0 && strcmp (argv[0], "tune"))
    goto not_found;

  f = fopen ("/proc/cpuinfo", "r");
  if (f == NULL)
    goto not_found;

  while (fgets (buf, sizeof (buf), f) != NULL)
    {
      /* Ensure that CPU implementer is ARM (0x41).  */
      if (strncmp (buf, "CPU implementer", sizeof ("CPU implementer") - 1) == 0)
	{
	  int i;
	  for (i = 0; vendors[i].vendor_no != NULL; i++)
	    if (strstr (buf, vendors[i].vendor_no) != NULL)
	      {
		cpu_table = vendors[i].vendor_parts;
		break;
	      }
	}

      /* Detect arch/cpu.  */
      if (strncmp (buf, "CPU part", sizeof ("CPU part") - 1) == 0)
	{
	  int i;

	  if (cpu_table == NULL)
	    goto not_found;

	  for (i = 0; cpu_table[i].part_no != NULL; i++)
	    if (strstr (buf, cpu_table[i].part_no) != NULL)
	      {
		val = arch ? cpu_table[i].arch_name : cpu_table[i].cpu_name;
		break;
	      }
	  break;
	}
    }

  fclose (f);

  if (val == NULL)
    goto not_found;

  return concat ("-m", argv[0], "=", val, NULL);

not_found:
  {
    unsigned int i;
    unsigned int opt;
    const char *search[] = {NULL, "arch"};

    if (f)
      fclose (f);

    search[0] = argv[0];
    for (opt = 0; opt < ARRAY_SIZE (search); opt++)
      for (i = 0; i < ARRAY_SIZE (configure_default_options); i++)
	if (strcmp (configure_default_options[i].name, search[opt]) == 0)
	  return concat ("-m", search[opt], "=",
			 configure_default_options[i].value, NULL);
    return NULL;
  }
}