binutils-gdb/gdb/p-lang.c
Andrew Burgess 7bea47f001 gdb: rewrite how per language primitive types are managed
Consider the following GDB session:

  $ gdb
  (gdb) set language c
  (gdb) ptype void
  type = void
  (gdb) set language fortran
  (gdb) ptype void
  No symbol table is loaded.  Use the "file" command.
  (gdb)

With no symbol file loaded GDB and the language set to C GDB knows
about the type void, while when the language is set to Fortran GDB
doesn't know about the void, why is that?

In f-lang.c, f_language::language_arch_info, we do have this line:

  lai->primitive_type_vector [f_primitive_type_void]
    = builtin->builtin_void;

where we add the void type to the list of primitive types that GDB
should always know about, so what's going wrong?

It turns out that the primitive types are stored in a C style array,
indexed by an enum, so Fortran uses `enum f_primitive_types'.  The
array is allocated and populated in each languages language_arch_info
member function.  The array is allocated with an extra entry at the
end which is left as a NULL value, and this indicates the end of the
array of types.

Unfortunately for Fortran, a type is not assigned for each element in
the enum.  As a result the final populated array has gaps in it, gaps
which are initialised to NULL, and so every time we iterate over the
list (for Fortran) we stop early, and never reach the void type.

This has been the case since 2007 when this functionality was added to
GDB in commit cad351d11d.

Obviously I could just fix Fortran by ensuring that either the enum is
trimmed, or we create types for the missing types.  However, I think a
better approach would be to move to C++ data structures and removed
the fixed enum indexing into the array approach.

After this commit the primitive types are pushed into a vector, and
GDB just iterates over the vector in the obvious way when it needs to
hunt for a type.  After this commit all the currently defined
primitive types can be found when the language is set to Fortran, for
example:

  $ gdb
  (gdb) set language fortran
  (gdb) ptype void
  type = void
  (gdb)

A new test checks this functionality.

I didn't see any other languages with similar issues, but I could have
missed something.

gdb/ChangeLog:

	* ada-exp.y (find_primitive_type): Make parameter const.
	* ada-lang.c (enum ada_primitive_types): Delete.
	(ada_language::language_arch_info): Update.
	* c-lang.c (enum c_primitive_types): Delete.
	(c_language_arch_info): Update.
	(enum cplus_primitive_types): Delete.
	(cplus_language::language_arch_info): Update.
	* d-lang.c (enum d_primitive_types): Delete.
	(d_language::language_arch_info): Update.
	* f-lang.c (enum f_primitive_types): Delete.
	(f_language::language_arch_info): Update.
	* go-lang.c (enum go_primitive_types): Delete.
	(go_language::language_arch_info): Update.
	* language.c (auto_or_unknown_language::language_arch_info):
	Update.
	(language_gdbarch_post_init): Use obstack_new, use array indexing.
	(language_string_char_type): Add header comment, call function in
	language_arch_info.
	(language_bool_type): Likewise
	(language_arch_info::bool_type): Define.
	(language_lookup_primitive_type_1): Delete.
	(language_lookup_primitive_type): Rewrite as a templated function
	to call function in language_arch_info, then instantiate twice.
	(language_arch_info::type_and_symbol::alloc_type_symbol): Define.
	(language_arch_info::lookup_primitive_type_and_symbol): Define.
	(language_arch_info::lookup_primitive_type): Define twice with
	different signatures.
	(language_arch_info::lookup_primitive_type_as_symbol): Define.
	(language_lookup_primitive_type_as_symbol): Rewrite to call a
	member function in language_arch_info.
	* language.h (language_arch_info): Complete rewrite.
	(language_lookup_primitive_type): Make templated.
	* m2-lang.c (enum m2_primitive_types): Delete.
	(m2_language::language_arch_info): Update.
	* opencl-lang.c (OCL_P_TYPE): Delete.
	(enum opencl_primitive_types): Delete.
	(opencl_type_data): Delete.
	(builtin_opencl_type): Delete.
	(lookup_opencl_vector_type): Update.
	(opencl_language::language_arch_info): Update, lots of content
	moved from...
	(build_opencl_types): ...here.  This function is now deleted.
	(_initialize_opencl_language): Delete.
	* p-lang.c (enum pascal_primitive_types): Delete.
	(pascal_language::language_arch_info): Update.
	* rust-lang.c (enum rust_primitive_types): Delete.
	(rust_language::language_arch_info): Update.

gdb/testsuite/ChangeLog:

	* gdb.fortran/types.exp: Add more tests.
2020-11-12 23:36:25 +00:00

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/* Pascal language support routines for GDB, the GNU debugger.
Copyright (C) 2000-2020 Free Software Foundation, Inc.
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/>. */
/* This file is derived from c-lang.c */
#include "defs.h"
#include "symtab.h"
#include "gdbtypes.h"
#include "expression.h"
#include "parser-defs.h"
#include "language.h"
#include "varobj.h"
#include "p-lang.h"
#include "valprint.h"
#include "value.h"
#include <ctype.h>
#include "c-lang.h"
#include "gdbarch.h"
#include "cli/cli-style.h"
/* All GPC versions until now (2007-09-27) also define a symbol called
'_p_initialize'. Check for the presence of this symbol first. */
static const char GPC_P_INITIALIZE[] = "_p_initialize";
/* The name of the symbol that GPC uses as the name of the main
procedure (since version 20050212). */
static const char GPC_MAIN_PROGRAM_NAME_1[] = "_p__M0_main_program";
/* Older versions of GPC (versions older than 20050212) were using
a different name for the main procedure. */
static const char GPC_MAIN_PROGRAM_NAME_2[] = "pascal_main_program";
/* Function returning the special symbol name used
by GPC for the main procedure in the main program
if it is found in minimal symbol list.
This function tries to find minimal symbols generated by GPC
so that it finds the even if the program was compiled
without debugging information.
According to information supplied by Waldeck Hebisch,
this should work for all versions posterior to June 2000. */
const char *
pascal_main_name (void)
{
struct bound_minimal_symbol msym;
msym = lookup_minimal_symbol (GPC_P_INITIALIZE, NULL, NULL);
/* If '_p_initialize' was not found, the main program is likely not
written in Pascal. */
if (msym.minsym == NULL)
return NULL;
msym = lookup_minimal_symbol (GPC_MAIN_PROGRAM_NAME_1, NULL, NULL);
if (msym.minsym != NULL)
{
return GPC_MAIN_PROGRAM_NAME_1;
}
msym = lookup_minimal_symbol (GPC_MAIN_PROGRAM_NAME_2, NULL, NULL);
if (msym.minsym != NULL)
{
return GPC_MAIN_PROGRAM_NAME_2;
}
/* No known entry procedure found, the main program is probably
not compiled with GPC. */
return NULL;
}
/* Determines if type TYPE is a pascal string type.
Returns a positive value if the type is a known pascal string type.
This function is used by p-valprint.c code to allow better string display.
If it is a pascal string type, then it also sets info needed
to get the length and the data of the string
length_pos, length_size and string_pos are given in bytes.
char_size gives the element size in bytes.
FIXME: if the position or the size of these fields
are not multiple of TARGET_CHAR_BIT then the results are wrong
but this does not happen for Free Pascal nor for GPC. */
int
is_pascal_string_type (struct type *type,int *length_pos,
int *length_size, int *string_pos,
struct type **char_type,
const char **arrayname)
{
if (type != NULL && type->code () == TYPE_CODE_STRUCT)
{
/* Old Borland type pascal strings from Free Pascal Compiler. */
/* Two fields: length and st. */
if (type->num_fields () == 2
&& TYPE_FIELD_NAME (type, 0)
&& strcmp (TYPE_FIELD_NAME (type, 0), "length") == 0
&& TYPE_FIELD_NAME (type, 1)
&& strcmp (TYPE_FIELD_NAME (type, 1), "st") == 0)
{
if (length_pos)
*length_pos = TYPE_FIELD_BITPOS (type, 0) / TARGET_CHAR_BIT;
if (length_size)
*length_size = TYPE_LENGTH (type->field (0).type ());
if (string_pos)
*string_pos = TYPE_FIELD_BITPOS (type, 1) / TARGET_CHAR_BIT;
if (char_type)
*char_type = TYPE_TARGET_TYPE (type->field (1).type ());
if (arrayname)
*arrayname = TYPE_FIELD_NAME (type, 1);
return 2;
};
/* GNU pascal strings. */
/* Three fields: Capacity, length and schema$ or _p_schema. */
if (type->num_fields () == 3
&& TYPE_FIELD_NAME (type, 0)
&& strcmp (TYPE_FIELD_NAME (type, 0), "Capacity") == 0
&& TYPE_FIELD_NAME (type, 1)
&& strcmp (TYPE_FIELD_NAME (type, 1), "length") == 0)
{
if (length_pos)
*length_pos = TYPE_FIELD_BITPOS (type, 1) / TARGET_CHAR_BIT;
if (length_size)
*length_size = TYPE_LENGTH (type->field (1).type ());
if (string_pos)
*string_pos = TYPE_FIELD_BITPOS (type, 2) / TARGET_CHAR_BIT;
/* FIXME: how can I detect wide chars in GPC ?? */
if (char_type)
{
*char_type = TYPE_TARGET_TYPE (type->field (2).type ());
if ((*char_type)->code () == TYPE_CODE_ARRAY)
*char_type = TYPE_TARGET_TYPE (*char_type);
}
if (arrayname)
*arrayname = TYPE_FIELD_NAME (type, 2);
return 3;
};
}
return 0;
}
static void pascal_one_char (int, struct ui_file *, int *);
/* Print the character C on STREAM as part of the contents of a literal
string.
In_quotes is reset to 0 if a char is written with #4 notation. */
static void
pascal_one_char (int c, struct ui_file *stream, int *in_quotes)
{
if (c == '\'' || ((unsigned int) c <= 0xff && (PRINT_LITERAL_FORM (c))))
{
if (!(*in_quotes))
fputs_filtered ("'", stream);
*in_quotes = 1;
if (c == '\'')
{
fputs_filtered ("''", stream);
}
else
fprintf_filtered (stream, "%c", c);
}
else
{
if (*in_quotes)
fputs_filtered ("'", stream);
*in_quotes = 0;
fprintf_filtered (stream, "#%d", (unsigned int) c);
}
}
void
pascal_printchar (int c, struct type *type, struct ui_file *stream)
{
int in_quotes = 0;
pascal_one_char (c, stream, &in_quotes);
if (in_quotes)
fputs_filtered ("'", stream);
}
/* Table mapping opcodes into strings for printing operators
and precedences of the operators. */
const struct op_print pascal_op_print_tab[] =
{
{",", BINOP_COMMA, PREC_COMMA, 0},
{":=", BINOP_ASSIGN, PREC_ASSIGN, 1},
{"or", BINOP_BITWISE_IOR, PREC_BITWISE_IOR, 0},
{"xor", BINOP_BITWISE_XOR, PREC_BITWISE_XOR, 0},
{"and", BINOP_BITWISE_AND, PREC_BITWISE_AND, 0},
{"=", BINOP_EQUAL, PREC_EQUAL, 0},
{"<>", BINOP_NOTEQUAL, PREC_EQUAL, 0},
{"<=", BINOP_LEQ, PREC_ORDER, 0},
{">=", BINOP_GEQ, PREC_ORDER, 0},
{">", BINOP_GTR, PREC_ORDER, 0},
{"<", BINOP_LESS, PREC_ORDER, 0},
{"shr", BINOP_RSH, PREC_SHIFT, 0},
{"shl", BINOP_LSH, PREC_SHIFT, 0},
{"+", BINOP_ADD, PREC_ADD, 0},
{"-", BINOP_SUB, PREC_ADD, 0},
{"*", BINOP_MUL, PREC_MUL, 0},
{"/", BINOP_DIV, PREC_MUL, 0},
{"div", BINOP_INTDIV, PREC_MUL, 0},
{"mod", BINOP_REM, PREC_MUL, 0},
{"@", BINOP_REPEAT, PREC_REPEAT, 0},
{"-", UNOP_NEG, PREC_PREFIX, 0},
{"not", UNOP_LOGICAL_NOT, PREC_PREFIX, 0},
{"^", UNOP_IND, PREC_SUFFIX, 1},
{"@", UNOP_ADDR, PREC_PREFIX, 0},
{"sizeof", UNOP_SIZEOF, PREC_PREFIX, 0},
{NULL, OP_NULL, PREC_PREFIX, 0}
};
/* Class representing the Pascal language. */
class pascal_language : public language_defn
{
public:
pascal_language ()
: language_defn (language_pascal)
{ /* Nothing. */ }
/* See language.h. */
const char *name () const override
{ return "pascal"; }
/* See language.h. */
const char *natural_name () const override
{ return "Pascal"; }
/* See language.h. */
const std::vector<const char *> &filename_extensions () const override
{
static const std::vector<const char *> extensions
= { ".pas", ".p", ".pp" };
return extensions;
}
/* See language.h. */
void language_arch_info (struct gdbarch *gdbarch,
struct language_arch_info *lai) const override
{
const struct builtin_type *builtin = builtin_type (gdbarch);
/* Helper function to allow shorter lines below. */
auto add = [&] (struct type * t)
{
lai->add_primitive_type (t);
};
add (builtin->builtin_int);
add (builtin->builtin_long);
add (builtin->builtin_short);
add (builtin->builtin_char);
add (builtin->builtin_float);
add (builtin->builtin_double);
add (builtin->builtin_void);
add (builtin->builtin_long_long);
add (builtin->builtin_signed_char);
add (builtin->builtin_unsigned_char);
add (builtin->builtin_unsigned_short);
add (builtin->builtin_unsigned_int);
add (builtin->builtin_unsigned_long);
add (builtin->builtin_unsigned_long_long);
add (builtin->builtin_long_double);
add (builtin->builtin_complex);
add (builtin->builtin_double_complex);
lai->set_string_char_type (builtin->builtin_char);
lai->set_bool_type (builtin->builtin_bool, "boolean");
}
/* See language.h. */
void print_type (struct type *type, const char *varstring,
struct ui_file *stream, int show, int level,
const struct type_print_options *flags) const override
{
pascal_print_type (type, varstring, stream, show, level, flags);
}
/* See language.h. */
void value_print (struct value *val, struct ui_file *stream,
const struct value_print_options *options) const override
{
return pascal_value_print (val, stream, options);
}
/* See language.h. */
void value_print_inner
(struct value *val, struct ui_file *stream, int recurse,
const struct value_print_options *options) const override
{
return pascal_value_print_inner (val, stream, recurse, options);
}
/* See language.h. */
int parser (struct parser_state *ps) const override
{
return pascal_parse (ps);
}
/* See language.h. */
void emitchar (int ch, struct type *chtype,
struct ui_file *stream, int quoter) const override
{
int in_quotes = 0;
pascal_one_char (ch, stream, &in_quotes);
if (in_quotes)
fputs_filtered ("'", stream);
}
/* See language.h. */
void printchar (int ch, struct type *chtype,
struct ui_file *stream) const override
{
pascal_printchar (ch, chtype, stream);
}
/* See language.h. */
void printstr (struct ui_file *stream, struct type *elttype,
const gdb_byte *string, unsigned int length,
const char *encoding, int force_ellipses,
const struct value_print_options *options) const override
{
enum bfd_endian byte_order = type_byte_order (elttype);
unsigned int i;
unsigned int things_printed = 0;
int in_quotes = 0;
int need_comma = 0;
int width;
/* Preserve ELTTYPE's original type, just set its LENGTH. */
check_typedef (elttype);
width = TYPE_LENGTH (elttype);
/* If the string was not truncated due to `set print elements', and
the last byte of it is a null, we don't print that, in traditional C
style. */
if ((!force_ellipses) && length > 0
&& extract_unsigned_integer (string + (length - 1) * width, width,
byte_order) == 0)
length--;
if (length == 0)
{
fputs_filtered ("''", stream);
return;
}
for (i = 0; i < length && things_printed < options->print_max; ++i)
{
/* Position of the character we are examining
to see whether it is repeated. */
unsigned int rep1;
/* Number of repetitions we have detected so far. */
unsigned int reps;
unsigned long int current_char;
QUIT;
if (need_comma)
{
fputs_filtered (", ", stream);
need_comma = 0;
}
current_char = extract_unsigned_integer (string + i * width, width,
byte_order);
rep1 = i + 1;
reps = 1;
while (rep1 < length
&& extract_unsigned_integer (string + rep1 * width, width,
byte_order) == current_char)
{
++rep1;
++reps;
}
if (reps > options->repeat_count_threshold)
{
if (in_quotes)
{
fputs_filtered ("', ", stream);
in_quotes = 0;
}
pascal_printchar (current_char, elttype, stream);
fprintf_filtered (stream, " %p[<repeats %u times>%p]",
metadata_style.style ().ptr (),
reps, nullptr);
i = rep1 - 1;
things_printed += options->repeat_count_threshold;
need_comma = 1;
}
else
{
if ((!in_quotes) && (PRINT_LITERAL_FORM (current_char)))
{
fputs_filtered ("'", stream);
in_quotes = 1;
}
pascal_one_char (current_char, stream, &in_quotes);
++things_printed;
}
}
/* Terminate the quotes if necessary. */
if (in_quotes)
fputs_filtered ("'", stream);
if (force_ellipses || i < length)
fputs_filtered ("...", stream);
}
/* See language.h. */
void print_typedef (struct type *type, struct symbol *new_symbol,
struct ui_file *stream) const override
{
pascal_print_typedef (type, new_symbol, stream);
}
/* See language.h. */
bool is_string_type_p (struct type *type) const override
{
return is_pascal_string_type (type, nullptr, nullptr, nullptr,
nullptr, nullptr) > 0;
}
/* See language.h. */
const char *name_of_this () const override
{ return "this"; }
/* See language.h. */
bool range_checking_on_by_default () const override
{ return true; }
/* See language.h. */
const struct op_print *opcode_print_table () const override
{ return pascal_op_print_tab; }
};
/* Single instance of the Pascal language class. */
static pascal_language pascal_language_defn;