binutils-gdb/gdb/f-lang.c

/* Fortran language support routines for GDB, the GNU debugger.

   Copyright (C) 1993-2019 Free Software Foundation, Inc.

   Contributed by Motorola.  Adapted from the C parser by Farooq Butt
   (fmbutt@engage.sps.mot.com).

   This file is part of GDB.

   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 3 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, see <http://www.gnu.org/licenses/>.  */

#include "defs.h"
#include "symtab.h"
#include "gdbtypes.h"
#include "expression.h"
#include "parser-defs.h"
#include "language.h"
#include "varobj.h"
#include "gdbcore.h"
#include "f-lang.h"
#include "valprint.h"
#include "value.h"
#include "cp-support.h"
#include "charset.h"
#include "c-lang.h"
#include "target-float.h"

#include <math.h>

/* Local functions */

static void f_printchar (int c, struct type *type, struct ui_file * stream);
static void f_emit_char (int c, struct type *type,
			 struct ui_file * stream, int quoter);

/* Return the encoding that should be used for the character type
   TYPE.  */

static const char *
f_get_encoding (struct type *type)
{
  const char *encoding;

  switch (TYPE_LENGTH (type))
    {
    case 1:
      encoding = target_charset (get_type_arch (type));
      break;
    case 4:
      if (gdbarch_byte_order (get_type_arch (type)) == BFD_ENDIAN_BIG)
	encoding = "UTF-32BE";
      else
	encoding = "UTF-32LE";
      break;

    default:
      error (_("unrecognized character type"));
    }

  return encoding;
}

/* Print the character C on STREAM as part of the contents of a literal
   string whose delimiter is QUOTER.  Note that that format for printing
   characters and strings is language specific.
   FIXME:  This is a copy of the same function from c-exp.y.  It should
   be replaced with a true F77 version.  */

static void
f_emit_char (int c, struct type *type, struct ui_file *stream, int quoter)
{
  const char *encoding = f_get_encoding (type);

  generic_emit_char (c, type, stream, quoter, encoding);
}

/* Implementation of la_printchar.  */

static void
f_printchar (int c, struct type *type, struct ui_file *stream)
{
  fputs_filtered ("'", stream);
  LA_EMIT_CHAR (c, type, stream, '\'');
  fputs_filtered ("'", stream);
}

/* Print the character string STRING, printing at most LENGTH characters.
   Printing stops early if the number hits print_max; repeat counts
   are printed as appropriate.  Print ellipses at the end if we
   had to stop before printing LENGTH characters, or if FORCE_ELLIPSES.
   FIXME:  This is a copy of the same function from c-exp.y.  It should
   be replaced with a true F77 version.  */

static void
f_printstr (struct ui_file *stream, struct type *type, const gdb_byte *string,
	    unsigned int length, const char *encoding, int force_ellipses,
	    const struct value_print_options *options)
{
  const char *type_encoding = f_get_encoding (type);

  if (TYPE_LENGTH (type) == 4)
    fputs_filtered ("4_", stream);

  if (!encoding || !*encoding)
    encoding = type_encoding;

  generic_printstr (stream, type, string, length, encoding,
		    force_ellipses, '\'', 0, options);
}


/* Table of operators and their precedences for printing expressions.  */

static const struct op_print f_op_print_tab[] =
{
  {"+", BINOP_ADD, PREC_ADD, 0},
  {"+", UNOP_PLUS, PREC_PREFIX, 0},
  {"-", BINOP_SUB, PREC_ADD, 0},
  {"-", UNOP_NEG, PREC_PREFIX, 0},
  {"*", BINOP_MUL, PREC_MUL, 0},
  {"/", BINOP_DIV, PREC_MUL, 0},
  {"DIV", BINOP_INTDIV, PREC_MUL, 0},
  {"MOD", BINOP_REM, PREC_MUL, 0},
  {"=", BINOP_ASSIGN, PREC_ASSIGN, 1},
  {".OR.", BINOP_LOGICAL_OR, PREC_LOGICAL_OR, 0},
  {".AND.", BINOP_LOGICAL_AND, PREC_LOGICAL_AND, 0},
  {".NOT.", UNOP_LOGICAL_NOT, PREC_PREFIX, 0},
  {".EQ.", BINOP_EQUAL, PREC_EQUAL, 0},
  {".NE.", BINOP_NOTEQUAL, PREC_EQUAL, 0},
  {".LE.", BINOP_LEQ, PREC_ORDER, 0},
  {".GE.", BINOP_GEQ, PREC_ORDER, 0},
  {".GT.", BINOP_GTR, PREC_ORDER, 0},
  {".LT.", BINOP_LESS, PREC_ORDER, 0},
  {"**", UNOP_IND, PREC_PREFIX, 0},
  {"@", BINOP_REPEAT, PREC_REPEAT, 0},
  {NULL, OP_NULL, PREC_REPEAT, 0}
};

enum f_primitive_types {
  f_primitive_type_character,
  f_primitive_type_logical,
  f_primitive_type_logical_s1,
  f_primitive_type_logical_s2,
  f_primitive_type_logical_s8,
  f_primitive_type_integer,
  f_primitive_type_integer_s2,
  f_primitive_type_real,
  f_primitive_type_real_s8,
  f_primitive_type_real_s16,
  f_primitive_type_complex_s8,
  f_primitive_type_complex_s16,
  f_primitive_type_void,
  nr_f_primitive_types
};

static void
f_language_arch_info (struct gdbarch *gdbarch,
		      struct language_arch_info *lai)
{
  const struct builtin_f_type *builtin = builtin_f_type (gdbarch);

  lai->string_char_type = builtin->builtin_character;
  lai->primitive_type_vector
    = GDBARCH_OBSTACK_CALLOC (gdbarch, nr_f_primitive_types + 1,
                              struct type *);

  lai->primitive_type_vector [f_primitive_type_character]
    = builtin->builtin_character;
  lai->primitive_type_vector [f_primitive_type_logical]
    = builtin->builtin_logical;
  lai->primitive_type_vector [f_primitive_type_logical_s1]
    = builtin->builtin_logical_s1;
  lai->primitive_type_vector [f_primitive_type_logical_s2]
    = builtin->builtin_logical_s2;
  lai->primitive_type_vector [f_primitive_type_logical_s8]
    = builtin->builtin_logical_s8;
  lai->primitive_type_vector [f_primitive_type_real]
    = builtin->builtin_real;
  lai->primitive_type_vector [f_primitive_type_real_s8]
    = builtin->builtin_real_s8;
  lai->primitive_type_vector [f_primitive_type_real_s16]
    = builtin->builtin_real_s16;
  lai->primitive_type_vector [f_primitive_type_complex_s8]
    = builtin->builtin_complex_s8;
  lai->primitive_type_vector [f_primitive_type_complex_s16]
    = builtin->builtin_complex_s16;
  lai->primitive_type_vector [f_primitive_type_void]
    = builtin->builtin_void;

  lai->bool_type_symbol = "logical";
  lai->bool_type_default = builtin->builtin_logical_s2;
}

/* Remove the modules separator :: from the default break list.  */

static const char *
f_word_break_characters (void)
{
  static char *retval;

  if (!retval)
    {
      char *s;

      retval = xstrdup (default_word_break_characters ());
      s = strchr (retval, ':');
      if (s)
	{
	  char *last_char = &s[strlen (s) - 1];

	  *s = *last_char;
	  *last_char = 0;
	}
    }
  return retval;
}

/* Consider the modules separator :: as a valid symbol name character
   class.  */

static void
f_collect_symbol_completion_matches (completion_tracker &tracker,
				     complete_symbol_mode mode,
				     symbol_name_match_type compare_name,
				     const char *text, const char *word,
				     enum type_code code)
{
  default_collect_symbol_completion_matches_break_on (tracker, mode,
						      compare_name,
						      text, word, ":", code);
}

/* Special expression evaluation cases for Fortran.  */
struct value *
evaluate_subexp_f (struct type *expect_type, struct expression *exp,
		   int *pos, enum noside noside)
{
  struct value *arg1 = NULL;
  enum exp_opcode op;
  int pc;
  struct type *type;

  pc = *pos;
  *pos += 1;
  op = exp->elts[pc].opcode;

  switch (op)
    {
    default:
      *pos -= 1;
      return evaluate_subexp_standard (expect_type, exp, pos, noside);

    case UNOP_ABS:
      arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
      if (noside == EVAL_SKIP)
	return eval_skip_value (exp);
      type = value_type (arg1);
      switch (TYPE_CODE (type))
	{
	case TYPE_CODE_FLT:
	  {
	    double d
	      = fabs (target_float_to_host_double (value_contents (arg1),
						   value_type (arg1)));
	    return value_from_host_double (type, d);
	  }
	case TYPE_CODE_INT:
	  {
	    LONGEST l = value_as_long (arg1);
	    l = llabs (l);
	    return value_from_longest (type, l);
	  }
	}
      error (_("ABS of type %s not supported"), TYPE_SAFE_NAME (type));

    case UNOP_FORTRAN_KIND:
      arg1 = evaluate_subexp (NULL, exp, pos, EVAL_AVOID_SIDE_EFFECTS);
      type = value_type (arg1);

      switch (TYPE_CODE (type))
        {
          case TYPE_CODE_STRUCT:
          case TYPE_CODE_UNION:
          case TYPE_CODE_MODULE:
          case TYPE_CODE_FUNC:
            error (_("argument to kind must be an intrinsic type"));
        }

      if (!TYPE_TARGET_TYPE (type))
        return value_from_longest (builtin_type (exp->gdbarch)->builtin_int,
				   TYPE_LENGTH (type));
      return value_from_longest (builtin_type (exp->gdbarch)->builtin_int,
				 TYPE_LENGTH (TYPE_TARGET_TYPE(type)));
    }

  /* Should be unreachable.  */
  return nullptr;
}

/* Return true if TYPE is a string.  */

static bool
f_is_string_type_p (struct type *type)
{
  type = check_typedef (type);
  return (TYPE_CODE (type) == TYPE_CODE_STRING
	  || (TYPE_CODE (type) == TYPE_CODE_ARRAY
	      && TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_CHAR));
}

/* Special expression lengths for Fortran.  */

static void
operator_length_f (const struct expression *exp, int pc, int *oplenp,
		   int *argsp)
{
  int oplen = 1;
  int args = 0;

  switch (exp->elts[pc - 1].opcode)
    {
    default:
      operator_length_standard (exp, pc, oplenp, argsp);
      return;

    case UNOP_FORTRAN_KIND:
      oplen = 1;
      args = 1;
      break;
    }

  *oplenp = oplen;
  *argsp = args;
}

/* Special expression printing for Fortran.  */

static void
print_subexp_f (struct expression *exp, int *pos,
		struct ui_file *stream, enum precedence prec)
{
  int pc = *pos;
  enum exp_opcode op = exp->elts[pc].opcode;

  switch (op)
    {
    default:
      print_subexp_standard (exp, pos, stream, prec);
      return;

    case UNOP_FORTRAN_KIND:
      (*pos)++;
      fputs_filtered ("KIND(", stream);
      print_subexp (exp, pos, stream, PREC_SUFFIX);
      fputs_filtered (")", stream);
      return;
    }
}

/* Special expression names for Fortran.  */

static const char *
op_name_f (enum exp_opcode opcode)
{
  switch (opcode)
    {
    default:
      return op_name_standard (opcode);

#define OP(name)	\
    case name:		\
      return #name ;
#include "fortran-operator.def"
#undef OP
    }
}

/* Special expression dumping for Fortran.  */

static int
dump_subexp_body_f (struct expression *exp,
		    struct ui_file *stream, int elt)
{
  int opcode = exp->elts[elt].opcode;
  int oplen, nargs, i;

  switch (opcode)
    {
    default:
      return dump_subexp_body_standard (exp, stream, elt);

    case UNOP_FORTRAN_KIND:
      operator_length_f (exp, (elt + 1), &oplen, &nargs);
      break;
    }

  elt += oplen;
  for (i = 0; i < nargs; i += 1)
    elt = dump_subexp (exp, stream, elt);

  return elt;
}

/* Special expression checking for Fortran.  */

static int
operator_check_f (struct expression *exp, int pos,
		  int (*objfile_func) (struct objfile *objfile,
				       void *data),
		  void *data)
{
  const union exp_element *const elts = exp->elts;

  switch (elts[pos].opcode)
    {
    case UNOP_FORTRAN_KIND:
      /* Any references to objfiles are held in the arguments to this
	 expression, not within the expression itself, so no additional
	 checking is required here, the outer expression iteration code
	 will take care of checking each argument.  */
      break;

    default:
      return operator_check_standard (exp, pos, objfile_func, data);
    }

  return 0;
}

static const char *f_extensions[] =
{
  ".f", ".F", ".for", ".FOR", ".ftn", ".FTN", ".fpp", ".FPP",
  ".f90", ".F90", ".f95", ".F95", ".f03", ".F03", ".f08", ".F08",
  NULL
};

/* Expression processing for Fortran.  */
static const struct exp_descriptor exp_descriptor_f =
{
  print_subexp_f,
  operator_length_f,
  operator_check_f,
  op_name_f,
  dump_subexp_body_f,
  evaluate_subexp_f
};

extern const struct language_defn f_language_defn =
{
  "fortran",
  "Fortran",
  language_fortran,
  range_check_on,
  case_sensitive_off,
  array_column_major,
  macro_expansion_no,
  f_extensions,
  &exp_descriptor_f,
  f_parse,			/* parser */
  null_post_parser,
  f_printchar,			/* Print character constant */
  f_printstr,			/* function to print string constant */
  f_emit_char,			/* Function to print a single character */
  f_print_type,			/* Print a type using appropriate syntax */
  default_print_typedef,	/* Print a typedef using appropriate syntax */
  f_val_print,			/* Print a value using appropriate syntax */
  c_value_print,		/* FIXME */
  default_read_var_value,	/* la_read_var_value */
  NULL,				/* Language specific skip_trampoline */
  NULL,                    	/* name_of_this */
  false,			/* la_store_sym_names_in_linkage_form_p */
  cp_lookup_symbol_nonlocal,	/* lookup_symbol_nonlocal */
  basic_lookup_transparent_type,/* lookup_transparent_type */

  /* We could support demangling here to provide module namespaces
     also for inferiors with only minimal symbol table (ELF symbols).
     Just the mangling standard is not standardized across compilers
     and there is no DW_AT_producer available for inferiors with only
     the ELF symbols to check the mangling kind.  */
  NULL,				/* Language specific symbol demangler */
  NULL,
  NULL,				/* Language specific
				   class_name_from_physname */
  f_op_print_tab,		/* expression operators for printing */
  0,				/* arrays are first-class (not c-style) */
  1,				/* String lower bound */
  f_word_break_characters,
  f_collect_symbol_completion_matches,
  f_language_arch_info,
  default_print_array_index,
  default_pass_by_reference,
  default_get_string,
  c_watch_location_expression,
  NULL,				/* la_get_symbol_name_matcher */
  iterate_over_symbols,
  default_search_name_hash,
  &default_varobj_ops,
  NULL,
  NULL,
  f_is_string_type_p,
  "(...)"			/* la_struct_too_deep_ellipsis */
};

static void *
build_fortran_types (struct gdbarch *gdbarch)
{
  struct builtin_f_type *builtin_f_type
    = GDBARCH_OBSTACK_ZALLOC (gdbarch, struct builtin_f_type);

  builtin_f_type->builtin_void
    = arch_type (gdbarch, TYPE_CODE_VOID, TARGET_CHAR_BIT, "VOID");

  builtin_f_type->builtin_character
    = arch_type (gdbarch, TYPE_CODE_CHAR, TARGET_CHAR_BIT, "character");

  builtin_f_type->builtin_logical_s1
    = arch_boolean_type (gdbarch, TARGET_CHAR_BIT, 1, "logical*1");

  builtin_f_type->builtin_integer_s2
    = arch_integer_type (gdbarch, gdbarch_short_bit (gdbarch), 0,
			 "integer*2");

  builtin_f_type->builtin_integer_s8
    = arch_integer_type (gdbarch, gdbarch_long_long_bit (gdbarch), 0,
			 "integer*8");

  builtin_f_type->builtin_logical_s2
    = arch_boolean_type (gdbarch, gdbarch_short_bit (gdbarch), 1,
			 "logical*2");

  builtin_f_type->builtin_logical_s8
    = arch_boolean_type (gdbarch, gdbarch_long_long_bit (gdbarch), 1,
			 "logical*8");

  builtin_f_type->builtin_integer
    = arch_integer_type (gdbarch, gdbarch_int_bit (gdbarch), 0,
			 "integer");

  builtin_f_type->builtin_logical
    = arch_boolean_type (gdbarch, gdbarch_int_bit (gdbarch), 1,
			 "logical*4");

  builtin_f_type->builtin_real
    = arch_float_type (gdbarch, gdbarch_float_bit (gdbarch),
		       "real", gdbarch_float_format (gdbarch));
  builtin_f_type->builtin_real_s8
    = arch_float_type (gdbarch, gdbarch_double_bit (gdbarch),
		       "real*8", gdbarch_double_format (gdbarch));
  builtin_f_type->builtin_real_s16
    = arch_float_type (gdbarch, gdbarch_long_double_bit (gdbarch),
		       "real*16", gdbarch_long_double_format (gdbarch));

  builtin_f_type->builtin_complex_s8
    = arch_complex_type (gdbarch, "complex*8",
			 builtin_f_type->builtin_real);
  builtin_f_type->builtin_complex_s16
    = arch_complex_type (gdbarch, "complex*16",
			 builtin_f_type->builtin_real_s8);
  builtin_f_type->builtin_complex_s32
    = arch_complex_type (gdbarch, "complex*32",
			 builtin_f_type->builtin_real_s16);

  return builtin_f_type;
}

static struct gdbarch_data *f_type_data;

const struct builtin_f_type *
builtin_f_type (struct gdbarch *gdbarch)
{
  return (const struct builtin_f_type *) gdbarch_data (gdbarch, f_type_data);
}

void
_initialize_f_language (void)
{
  f_type_data = gdbarch_data_register_post_init (build_fortran_types);
}

/* See f-lang.h.  */

struct value *
fortran_argument_convert (struct value *value, bool is_artificial)
{
  if (!is_artificial)
    {
      /* If the value is not in the inferior e.g. registers values,
	 convenience variables and user input.  */
      if (VALUE_LVAL (value) != lval_memory)
	{
	  struct type *type = value_type (value);
	  const int length = TYPE_LENGTH (type);
	  const CORE_ADDR addr
	    = value_as_long (value_allocate_space_in_inferior (length));
	  write_memory (addr, value_contents (value), length);
	  struct value *val
	    = value_from_contents_and_address (type, value_contents (value),
					       addr);
	  return value_addr (val);
	}
      else
	return value_addr (value); /* Program variables, e.g. arrays.  */
    }
    return value;
}

/* See f-lang.h.  */

struct type *
fortran_preserve_arg_pointer (struct value *arg, struct type *type)
{
  if (TYPE_CODE (value_type (arg)) == TYPE_CODE_PTR)
    return value_type (arg);
  return type;
}