binutils-gdb/gas/read.h
H.J. Lu 62a02d25b6 Add .nop assembler directive
Implement the '.nop SIZE[, CONTROL]' assembler directive, which emits
SIZE bytes filled with no-op instructions.  SIZE is absolute expression.
The optional CONTROL byte controls how no-op instructions should be
generated.  If the comma and @var{control} are omitted, CONTROL is
assumed to be zero.

For Intel 80386 and AMD x86-64 targets, CONTROL byte specifies the size
limit of a single no-op instruction.  The valid values of CONTROL byte
are between 0 and 8 for 16-bit mode, between 0 and 10 for 32-bit mode,
between 0 and 11 for 64-bit mode.  When 0 is used, the no-op size limit
is set to the maximum supported size.

2 new relax states, rs_space_nop and rs_fill_nop, are added to enum
_relax_state, which are similar to rs_space and rs_fill, respectively,
but they fill with no-op instructions, instead of a single byte.  A
target backend must override the default md_generate_nops to generate
proper no-op instructions.  Otherwise, an error of unimplemented .nop
directive will be issued whenever .nop directive is used.

	* NEWS: Mention .nop directive.
	* as.h (_relax_state): Add rs_space_nop and rs_fill_nop.
	* read.c (potable): Add .nop.
	(s_nop): New function.
	* read.h (s_nop): New prototype.
	* write.c (cvt_frag_to_fill): Handle rs_space_nop and
	rs_fill_nop.
	(md_generate_nops): New function.
	(relax_segment): Likewise.
	(write_contents): Use md_generate_nops for rs_fill_nop.
	* config/tc-i386.c (alt64_11): New.
	(alt64_patt): Likewise.
	(md_convert_frag): Handle rs_space_nop.
	(i386_output_nops): New function.
	(i386_generate_nops): Likewise.
	(i386_align_code): Call i386_output_nops.
	* config/tc-i386.h (i386_generate_nops): New.
	(md_generate_nops): Likewise.
	* doc/as.texinfo: Document .nop directive.
	* testsuite/gas/i386/i386.exp: Run .nop directive tests.
	* testsuite/gas/i386/nop-1.d: New file.
	* testsuite/gas/i386/nop-1.s: Likewise.
	* testsuite/gas/i386/nop-2.d: Likewise.
	* testsuite/gas/i386/nop-2.s: Likewise.
	* testsuite/gas/i386/nop-3.d: Likewise.
	* testsuite/gas/i386/nop-3.s: Likewise.
	* testsuite/gas/i386/nop-4.d: Likewise.
	* testsuite/gas/i386/nop-4.s: Likewise.
	* testsuite/gas/i386/nop-5.d: Likewise.
	* testsuite/gas/i386/nop-5.s: Likewise.
	* testsuite/gas/i386/nop-6.d: Likewise.
	* testsuite/gas/i386/nop-6.s: Likewise.
	* testsuite/gas/i386/nop-bad-1.l: Likewise.
	* testsuite/gas/i386/nop-bad-1.s: Likewise.
	* testsuite/gas/i386/x86-64-nop-1.d: Likewise.
	* testsuite/gas/i386/x86-64-nop-2.d: Likewise.
	* testsuite/gas/i386/x86-64-nop-3.d: Likewise.
	* testsuite/gas/i386/x86-64-nop-4.d: Likewise.
	* testsuite/gas/i386/x86-64-nop-5.d: Likewise.
	* testsuite/gas/i386/x86-64-nop-6.d: Likewise.
2018-02-17 05:20:57 -08:00

220 lines
7.4 KiB
C

/* read.h - of read.c
Copyright (C) 1986-2018 Free Software Foundation, Inc.
This file is part of GAS, the GNU Assembler.
GAS 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.
GAS 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 GAS; see the file COPYING. If not, write to the Free
Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
02110-1301, USA. */
extern char *input_line_pointer; /* -> char we are parsing now. */
extern bfd_boolean input_from_string;
/* Define to make whitespace be allowed in many syntactically
unnecessary places. Normally undefined. For compatibility with
ancient GNU cc. */
/* #undef PERMIT_WHITESPACE */
#define PERMIT_WHITESPACE
#ifdef PERMIT_WHITESPACE
#define SKIP_WHITESPACE() \
((*input_line_pointer == ' ') ? ++input_line_pointer : 0)
#define SKIP_ALL_WHITESPACE() \
while (*input_line_pointer == ' ') ++input_line_pointer
#else
#define SKIP_WHITESPACE() know (*input_line_pointer != ' ' )
#define SKIP_ALL_WHITESPACE() SKIP_WHITESPACE()
#endif
#define SKIP_WHITESPACE_AFTER_NAME() \
do \
{ \
if (* input_line_pointer == '"') \
++ input_line_pointer; \
if (* input_line_pointer == ' ') \
++ input_line_pointer; \
} \
while (0)
#define LEX_NAME (1) /* may continue a name */
#define LEX_BEGIN_NAME (2) /* may begin a name */
#define LEX_END_NAME (4) /* ends a name */
#define is_name_beginner(c) \
( lex_type[(unsigned char) (c)] & LEX_BEGIN_NAME )
#define is_part_of_name(c) \
( lex_type[(unsigned char) (c)] & LEX_NAME )
#define is_name_ender(c) \
( lex_type[(unsigned char) (c)] & LEX_END_NAME )
#ifndef is_a_char
#define CHAR_MASK (0xff)
#define NOT_A_CHAR (CHAR_MASK+1)
#define is_a_char(c) (((unsigned) (c)) <= CHAR_MASK)
#endif /* is_a_char() */
extern char lex_type[];
extern char is_end_of_line[];
extern int is_it_end_of_statement (void);
extern char *find_end_of_line (char *, int);
extern int target_big_endian;
/* These are initialized by the CPU specific target files (tc-*.c). */
extern const char comment_chars[];
extern const char line_comment_chars[];
extern const char line_separator_chars[];
/* Table of -I directories. */
extern const char **include_dirs;
extern int include_dir_count;
extern int include_dir_maxlen;
/* The offset in the absolute section. */
extern addressT abs_section_offset;
/* The label on a line, used by some of the pseudo-ops. */
extern symbolS *line_label;
/* This is used to support MRI common sections. */
extern symbolS *mri_common_symbol;
/* True if a stabs line debug statement is currently being emitted. */
extern int outputting_stabs_line_debug;
/* Possible arguments to .linkonce. */
enum linkonce_type {
LINKONCE_UNSET = 0,
LINKONCE_DISCARD,
LINKONCE_ONE_ONLY,
LINKONCE_SAME_SIZE,
LINKONCE_SAME_CONTENTS
};
#ifndef TC_CASE_SENSITIVE
extern char original_case_string[];
#endif
#ifndef TC_PARSE_CONS_RETURN_TYPE
#define TC_PARSE_CONS_RETURN_TYPE bfd_reloc_code_real_type
#define TC_PARSE_CONS_RETURN_NONE BFD_RELOC_NONE
#endif
extern void pop_insert (const pseudo_typeS *);
extern unsigned int get_stab_string_offset
(const char *string, const char *stabstr_secname);
extern void aout_process_stab (int, const char *, int, int, int);
extern char *demand_copy_string (int *lenP);
extern char *demand_copy_C_string (int *len_pointer);
extern char get_absolute_expression_and_terminator (long *val_pointer);
extern offsetT get_absolute_expression (void);
extern unsigned int next_char_of_string (void);
extern void s_mri_sect (char *);
extern char *mri_comment_field (char *);
extern void mri_comment_end (char *, int);
extern void add_include_dir (char *path);
extern void cons (int nbytes);
extern void demand_empty_rest_of_line (void);
extern void emit_expr (expressionS *exp, unsigned int nbytes);
extern void emit_expr_with_reloc (expressionS *exp, unsigned int nbytes,
TC_PARSE_CONS_RETURN_TYPE);
extern void emit_expr_fix (expressionS *, unsigned int, fragS *, char *,
TC_PARSE_CONS_RETURN_TYPE);
extern void equals (char *, int);
extern void float_cons (int);
extern void ignore_rest_of_line (void);
#define discard_rest_of_line ignore_rest_of_line
extern unsigned output_leb128 (char *, valueT, int);
extern void pseudo_set (symbolS * symbolP);
extern void read_a_source_file (const char *name);
extern void read_begin (void);
extern void read_print_statistics (FILE *);
extern char *read_symbol_name (void);
extern unsigned sizeof_leb128 (valueT, int);
extern void stabs_generate_asm_file (void);
extern void stabs_generate_asm_lineno (void);
extern void stabs_generate_asm_func (const char *, const char *);
extern void stabs_generate_asm_endfunc (const char *, const char *);
extern void do_repeat (size_t, const char *, const char *);
extern void do_repeat_with_expander (size_t, const char *, const char *, const char *);
extern void end_repeat (int);
extern void do_parse_cons_expression (expressionS *, int);
extern void generate_lineno_debug (void);
extern void s_abort (int) ATTRIBUTE_NORETURN;
extern void s_align_bytes (int arg);
extern void s_align_ptwo (int);
extern void do_align (unsigned int align, char *fill, unsigned int length,
unsigned int max);
extern void bss_alloc (symbolS *, addressT, unsigned);
extern offsetT parse_align (int);
extern symbolS *s_comm_internal (int, symbolS *(*) (int, symbolS *, addressT));
extern symbolS *s_lcomm_internal (int, symbolS *, addressT);
extern void s_app_file_string (char *, int);
extern void s_app_file (int);
extern void s_app_line (int);
extern void s_bundle_align_mode (int);
extern void s_bundle_lock (int);
extern void s_bundle_unlock (int);
extern void s_comm (int);
extern void s_data (int);
extern void s_desc (int);
extern void s_else (int arg);
extern void s_elseif (int arg);
extern void s_end (int arg);
extern void s_endif (int arg);
extern void s_err (int);
extern void s_errwarn (int);
extern void s_fail (int);
extern void s_fill (int);
extern void s_float_space (int mult);
extern void s_func (int);
extern void s_globl (int arg);
extern void s_if (int arg);
extern void s_ifb (int arg);
extern void s_ifc (int arg);
extern void s_ifdef (int arg);
extern void s_ifeqs (int arg);
extern void s_ignore (int arg);
extern void s_include (int arg);
extern void s_irp (int arg);
extern void s_lcomm (int needs_align);
extern void s_lcomm_bytes (int needs_align);
extern void s_leb128 (int sign);
extern void s_linkonce (int);
extern void s_lsym (int);
extern void s_macro (int);
extern void s_mexit (int);
extern void s_mri (int);
extern void s_mri_common (int);
extern void s_org (int);
extern void s_print (int);
extern void s_purgem (int);
extern void s_rept (int);
extern void s_set (int);
extern void s_space (int mult);
extern void s_nop (int);
extern void s_stab (int what);
extern void s_struct (int);
extern void s_text (int);
extern void stringer (int append_zero);
extern void s_xstab (int what);
extern void s_rva (int);
extern void s_incbin (int);
extern void s_weakref (int);
extern void temp_ilp (char *);
extern void restore_ilp (void);