#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <errno.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <libmcpu.h>

#include "mcpu-ld-options.h"

static int
parse_size( const char *s, __mpu_uint64_t *v )
{
  unsigned long long  x;
  __mpu_uint64_t      m = 1;
  char               *e;

  if( !s || !*s || *s == '-' ) return( -1 );

  errno = 0;
  x = strtoull( s, &e, 0 );
  if( errno || e == s ) return( -1 );

  if( *e == '\0' )
    m = 1;
  else if( !strcmp( e, "K" ) || !strcmp( e, "KiB" ) )
    m = __mpu_UINT64_C( 1024 );
  else if( !strcmp( e, "M" ) || !strcmp( e, "MiB" ) )
    m = __mpu_UINT64_C( 1024 ) * __mpu_UINT64_C( 1024 );
  else if( !strcmp( e, "G" ) || !strcmp( e, "GiB" ) )
    m = __mpu_UINT64_C( 1024 ) * __mpu_UINT64_C( 1024 ) * __mpu_UINT64_C( 1024 );
  else
    return( -1 );

  if( (__mpu_uint64_t)x != x || (__mpu_uint64_t)x > UINT64_MAX / m )
    return( -1 );

  *v = (__mpu_uint64_t)x * m;
  return( 0 );

} /* End of parse_size() */


static int
append_input( mcpu_ld_options *options, char *name )
{
  char  **p;
  size_t  capacity;

  if( options->input_count == options->input_capacity )
  {
    capacity = options->input_capacity ? options->input_capacity * 2U : 8U;
    if( capacity < options->input_capacity ||
        capacity > SIZE_MAX / sizeof(*p) )
    {
      errno = EOVERFLOW;
      return( -1 );
    }

    p = (char **)realloc( options->inputs, capacity * sizeof(*p) );
    if( p == NULL )
      return( -1 );

    options->inputs = p;
    options->input_capacity = capacity;
  }

  options->inputs[options->input_count++] = name;
  return( 0 );

} /* End of append_input() */


static int
append_library( mcpu_ld_options *options, char *name )
{
  char  **p;
  size_t  capacity;

  if( options->library_count == options->library_capacity )
  {
    capacity = options->library_capacity ? options->library_capacity * 2U : 8U;
    if( capacity < options->library_capacity ||
        capacity > SIZE_MAX / sizeof(*p) )
    {
      errno = EOVERFLOW;
      return( -1 );
    }

    p = (char **)realloc( options->libraries, capacity * sizeof(*p) );
    if( p == NULL )
      return( -1 );

    options->libraries = p;
    options->library_capacity = capacity;
  }

  options->libraries[options->library_count++] = name;
  return( 0 );

} /* End of append_library() */


void
mcpu_ld_options_init( mcpu_ld_options *options, const char *progname )
{
  if( options == NULL )
    return;

  memset( options, 0, sizeof(*options) );
  mcpu_tool_options_init( &options->common, progname );
  options->exec.stack_size = 1048576U;
  options->exec.have_heap = 1;
  options->exec.heap_size = 1048576U;
  options->exec.heap_limit = 1048576U;
  options->mode = CPU_LINK_STATIC_EXEC;

} /* End of mcpu_ld_options_init() */


void
mcpu_ld_options_free( mcpu_ld_options *options )
{
  if( options == NULL )
    return;

  free( options->inputs );
  options->inputs = NULL;
  options->input_count = 0;
  options->input_capacity = 0;
  free( options->libraries );
  options->libraries = NULL;
  options->library_count = 0;
  options->library_capacity = 0;
  mcpu_tool_options_free( &options->common );

} /* End of mcpu_ld_options_free() */


void
mcpu_ld_usage( const mcpu_ld_options *options )
{
  const char *name = options ? options->common.progname : "mcpu-ld";

  fprintf( stderr,
    "usage: %s [link-options] -o output input.o ...\n\n"
    "Link LibMCPU MELF ET_REL object files.\n\n"
    "Output mode (at most one):\n"
    "  -r                         - produce one partial-link MELF ET_REL object\n"
    "  --shared                   - produce ABI-v3 MELF ET_DYN shared object\n"
    "  --dynamic                  - produce ABI-v3 startup-dynamic MELF ET_EXEC\n"
    "                               (default without these options: ABI-v1 static ET_EXEC)\n\n"
    "MCPU system options:\n"
    "  --no-config                - do not read mcpu-ld.conf files\n"
    "  --sys-root=PATH            - use PATH as MCPU root and do not read config files\n"
    "  --dump-config              - print effective MCPU configuration and exit\n"
    "  --print-search-dirs        - print effective library search directories and exit\n\n"
    "Library dependency options:\n"
    "  -L <dir>, -L<dir>          - add explicit MCPU library search directory\n"
    "  -l <name>, -l<name>        - link against lib<name>; ABI-v1 and -r search .a,\n"
    "                               ABI-v3 searches .so then .a in each directory\n"
    "  --static                   - force every -l<name> lookup to use lib<name>.a\n"
    "                               without changing the selected output mode\n"
    "                               (selected .so files alone create DT_NEEDED)\n\n"
    "Shared-library identity:\n"
    "  --soname=NAME              - set mandatory ABI-v3 ET_DYN SONAME\n"
    "  --soname NAME              - NAME must be a logical name without '/'\n\n"
    "Link options:\n"
    "  -o <file>                  - write output to <file>\n"
    "  --stack-size=<size>        - set fixed STACK size; positive and %u-byte aligned\n"
    "                               (default for executables: 1048576)\n"
    "  --heap-size=<size>         - set initial HEAP size (default: 1048576)\n"
    "  --heap-limit=<size>        - set immutable maximum HEAP size (default: 1048576)\n"
    "  --no-heap                  - omit PT_MCPU_HEAP from an executable\n"
    "  -v, --verbose              - print output-object summary\n"
    "  -h, --help                 - show this help\n"
    "      --version              - show program version\n"
    "      --dump-version         - show version number only\n\n"
    "<size> is bytes by default; K/KiB, M/MiB and G/GiB suffixes are accepted.\n"
    "K, M and G use binary multipliers (1024, 1024^2 and 1024^3).\n\n"
    "Partial -r output is MELF ET_REL: STACK/HEAP/SONAME and shared objects are\n"
    "not part of this mode; unresolved symbols and RELA records are preserved.\n"
    "Shared objects may contain only .text/.data/.bss allocated sections,\n"
    "must define --soname and must not use STACK/HEAP sizing options.  ABI-v3\n"
    "dynamic executables retain preemptible GLOBAL/WEAK relocations; mcpu-run\n"
    "continues to accept explicit --ldpreload and legacy ABI-v2 files.\n",
    name, CPU_ABI_STACK_ALIGN );

} /* End of mcpu_ld_usage() */


int
mcpu_ld_handle_options( mcpu_ld_options *options, int argc, char **argv )
{
  int i;

  if( options == NULL || argv == NULL )
  {
    errno = EINVAL;
    return( -1 );
  }

  for( i = 1; i < argc; ++i )
  {
    int common;

    if( !strcmp( argv[i], "-h" ) || !strcmp( argv[i], "--help" ) )
    {
      options->common.help = 1;
      return( 0 );
    }

    common = mcpu_tool_parse_common_option( &options->common,
                                            argc, argv, &i );
    if( common < 0 )
      return( -1 );
    if( common > 0 )
    {
      if( options->common.version_action != MCPU_VERSION_NONE )
        return( 0 );
      continue;
    }

    if( !strcmp( argv[i], "-v" ) || !strcmp( argv[i], "--verbose" ) )
    {
      options->verbose = 1;
    }
    else if( !strcmp( argv[i], "-r" ) )
    {
      if( options->mode_seen++ )
      {
        fprintf( stderr, "%s: -r/--shared/--dynamic are mutually exclusive\n",
                 options->common.progname );
        return( -1 );
      }
      options->mode = CPU_LINK_RELOCATABLE;
    }
    else if( !strcmp( argv[i], "--shared" ) )
    {
      if( options->mode_seen++ )
      {
        fprintf( stderr, "%s: -r/--shared/--dynamic are mutually exclusive\n",
                 options->common.progname );
        return( -1 );
      }
      options->mode = CPU_LINK_SHARED;
    }
    else if( !strcmp( argv[i], "--dynamic" ) )
    {
      if( options->mode_seen++ )
      {
        fprintf( stderr, "%s: -r/--shared/--dynamic are mutually exclusive\n",
                 options->common.progname );
        return( -1 );
      }
      options->mode = CPU_LINK_DYNAMIC_EXEC;
    }
    else if( !strcmp( argv[i], "--static" ) )
    {
      options->force_static = 1;
    }
    else if( !strncmp( argv[i], "--soname=", 9 ) )
    {
      const char *name = argv[i] + 9;

      if( options->soname != NULL || name[0] == 0 ||
          strchr( name, '/' ) != NULL )
      {
        fprintf( stderr, "%s: invalid or duplicate --soname\n",
                 options->common.progname );
        return( -1 );
      }
      options->soname = name;
    }
    else if( !strcmp( argv[i], "--soname" ) )
    {
      const char *name;

      if( ++i >= argc )
      {
        fprintf( stderr, "%s: argument missing after --soname\n",
                 options->common.progname );
        return( -1 );
      }
      name = argv[i];
      if( options->soname != NULL || name[0] == 0 ||
          strchr( name, '/' ) != NULL )
      {
        fprintf( stderr, "%s: invalid or duplicate --soname\n",
                 options->common.progname );
        return( -1 );
      }
      options->soname = name;
    }
    else if( !strcmp( argv[i], "-L" ) )
    {
      if( ++i >= argc || argv[i][0] == 0 ||
          mcpu_tool_add_library_directory(&options->common, argv[i]) != 0 )
      {
        fprintf( stderr, "%s: argument missing or invalid after -L\n",
                 options->common.progname );
        return( -1 );
      }
    }
    else if( !strncmp( argv[i], "-L", 2 ) )
    {
      if( argv[i][2] == 0 ||
          mcpu_tool_add_library_directory(&options->common, argv[i] + 2) != 0 )
      {
        fprintf( stderr, "%s: bad -L directory: %s\n",
                 options->common.progname, argv[i] + 2 );
        return( -1 );
      }
    }
    else if( !strcmp( argv[i], "-l" ) )
    {
      char *name;

      if( ++i >= argc )
      {
        fprintf( stderr, "%s: argument missing after -l\n",
                 options->common.progname );
        return( -1 );
      }
      name = argv[i];
      if( name[0] == 0 || strchr(name, '/') != NULL ||
          append_library(options, name) != 0 )
      {
        fprintf( stderr, "%s: invalid library name after -l: %s\n",
                 options->common.progname, name );
        return( -1 );
      }
    }
    else if( !strncmp( argv[i], "-l", 2 ) )
    {
      char *name = argv[i] + 2;

      if( name[0] == 0 || strchr(name, '/') != NULL ||
          append_library(options, name) != 0 )
      {
        fprintf( stderr, "%s: invalid library option: %s\n",
                 options->common.progname, argv[i] );
        return( -1 );
      }
    }
    else if( !strcmp( argv[i], "-o" ) )
    {
      if( ++i >= argc || options->out_fname != NULL )
      {
        mcpu_ld_usage( options );
        return( -1 );
      }
      options->out_fname = argv[i];
    }
    else if( !strncmp( argv[i], "--stack-size=", 13 ) )
    {
      options->size_option_seen = 1;
      if( parse_size(argv[i] + 13, &options->exec.stack_size) ||
          !options->exec.stack_size ||
          options->exec.stack_size % CPU_ABI_STACK_ALIGN )
      {
        fprintf( stderr, "%s: stack size must be a positive multiple of %u\n",
                 options->common.progname, CPU_ABI_STACK_ALIGN );
        return( -1 );
      }
    }
    else if( !strncmp( argv[i], "--heap-size=", 12 ) )
    {
      options->size_option_seen = 1;
      if( parse_size(argv[i] + 12, &options->exec.heap_size) ||
          options->exec.heap_size < CPU_HEAP_BEGIN )
      {
        fprintf( stderr, "%s: heap size must be at least %u\n",
                 options->common.progname, CPU_HEAP_BEGIN );
        return( -1 );
      }
      options->exec.have_heap = 1;
    }
    else if( !strncmp( argv[i], "--heap-limit=", 13 ) )
    {
      options->size_option_seen = 1;
      if( parse_size(argv[i] + 13, &options->exec.heap_limit) ||
          options->exec.heap_limit < CPU_HEAP_BEGIN )
      {
        fprintf( stderr, "%s: bad heap limit\n", options->common.progname );
        return( -1 );
      }
      options->exec.have_heap = 1;
    }
    else if( !strcmp( argv[i], "--no-heap" ) )
    {
      options->size_option_seen = 1;
      options->exec.have_heap = 0;
      options->exec.heap_size = options->exec.heap_limit = 0;
    }
    else if( argv[i][0] == '-' )
    {
      fprintf( stderr, "%s: unknown option %s\n",
               options->common.progname, argv[i] );
      return( -1 );
    }
    else if( append_input(options, argv[i]) != 0 )
    {
      perror( "realloc" );
      return( -1 );
    }
  }

  if( options->common.help ||
      mcpu_tool_has_information_action(&options->common) )
    return( 0 );

  if( options->out_fname == NULL || options->input_count == 0 )
  {
    mcpu_ld_usage( options );
    return( -1 );
  }

  if( options->mode == CPU_LINK_RELOCATABLE && options->size_option_seen )
  {
    fprintf( stderr, "%s: STACK/HEAP options are invalid with -r\n",
             options->common.progname );
    return( -1 );
  }

  if( options->mode == CPU_LINK_SHARED && options->size_option_seen )
  {
    fprintf( stderr, "%s: STACK/HEAP options are invalid with --shared\n",
             options->common.progname );
    return( -1 );
  }

  if( options->mode == CPU_LINK_SHARED && options->soname == NULL )
  {
    fprintf( stderr, "%s: ABI-v3 --shared requires --soname=NAME\n",
             options->common.progname );
    return( -1 );
  }

  if( options->mode != CPU_LINK_SHARED && options->soname != NULL )
  {
    fprintf( stderr, "%s: --soname is valid only with --shared\n",
             options->common.progname );
    return( -1 );
  }

  if( options->mode != CPU_LINK_SHARED &&
      options->mode != CPU_LINK_RELOCATABLE &&
      options->exec.have_heap &&
      options->exec.heap_limit < options->exec.heap_size )
  {
    fprintf( stderr, "%s: heap limit is smaller than heap size\n",
             options->common.progname );
    return( -1 );
  }

  return( 0 );

} /* End of mcpu_ld_handle_options() */