gas/itbl-parse.y - binutils-gdb - Git at Google

 /* itbl-parse.y
    Copyright (C) 1997-2020 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.  */

 %{

 /*

 Yacc grammar for instruction table entries.

 =======================================================================
 Original Instruction table specification document:

 	    MIPS Coprocessor Table Specification
 	    ====================================

 This document describes the format of the MIPS coprocessor table.  The
 table specifies a list of valid functions, data registers and control
 registers that can be used in coprocessor instructions.  This list,
 together with the coprocessor instruction classes listed below,
 specifies the complete list of coprocessor instructions that will
 be recognized and assembled by the GNU assembler.  In effect,
 this makes the GNU assembler table-driven, where the table is
 specified by the programmer.

 The table is an ordinary text file that the GNU assembler reads when
 it starts.  Using the information in the table, the assembler
 generates an internal list of valid coprocessor registers and
 functions.  The assembler uses this internal list in addition to the
 standard MIPS registers and instructions which are built-in to the
 assembler during code generation.

 To specify the coprocessor table when invoking the GNU assembler, use
 the command line option "--itbl file", where file is the
 complete name of the table, including path and extension.

 Examples:

 	    gas -t cop.tbl test.s -o test.o
 	    gas -t /usr/local/lib/cop.tbl test.s -o test.o
 	    gas --itbl d:\gnu\data\cop.tbl test.s -o test.o

 Only one table may be supplied during a single invocation of
 the assembler.


 Instruction classes
 ===================

 Below is a list of the valid coprocessor instruction classes for
 any given coprocessor "z".  These instructions are already recognized
 by the assembler, and are listed here only for reference.

 Class   format	    	    	      instructions
 -------------------------------------------------
 Class1:
 	op base rt offset
 	    	    	    	    	    	    	    LWCz rt,offset (base)
 	    	    	    	    	    	    	    SWCz rt,offset (base)
 Class2:
 	COPz sub rt rd 0
 	    	    	    	    	    	    	    MTCz rt,rd
 	    	    	    	    	    	    	    MFCz rt,rd
 	    	    	    	    	    	    	    CTCz rt,rd
 	    	    	    	    	    	    	    CFCz rt,rd
 Class3:
 	COPz CO cofun
 	    	    	    	    	    	    	    COPz cofun
 Class4:
 	COPz BC br offset
 	    	    	    	    	    	    	    BCzT offset
 	    	    	    	    	    	    	    BCzF offset
 Class5:
 	COPz sub rt rd 0
 	    	    	    	    	    	    	    DMFCz rt,rd
 	    	    	    	    	    	    	    DMTCz rt,rd
 Class6:
 	op base rt offset
 	    	    	    	    	    	    	    LDCz rt,offset (base)
 	    	    	    	    	    	    	    SDCz rt,offset (base)
 Class7:
 	COPz BC br offset
 	    	    	    	    	    	    	    BCzTL offset
 	    	    	    	    	    	    	    BCzFL offset

 The coprocessor table defines coprocessor-specific registers that can
 be used with all of the above classes of instructions, where
 appropriate.  It also defines additional coprocessor-specific
 functions for Class3 (COPz cofun) instructions, Thus, the table allows
 the programmer to use convenient mnemonics and operands for these
 functions, instead of the COPz mmenmonic and cofun operand.

 The names of the MIPS general registers and their aliases are defined
 by the assembler and will be recognized as valid register names by the
 assembler when used (where allowed) in coprocessor instructions.
 However, the names and values of all coprocessor data and control
 register mnemonics must be specified in the coprocessor table.


 Table Grammar
 =============

 Here is the grammar for the coprocessor table:

 	    table -> entry*

 	    entry -> [z entrydef] [comment] '\n'

 	    entrydef -> type name val
 	    entrydef -> 'insn' name val funcdef ; type of entry (instruction)

 	    z -> 'p'['0'..'3']	    	     ; processor number
 	    type -> ['dreg' | 'creg' | 'greg' ]	     ; type of entry (register)
 	; 'dreg', 'creg' or 'greg' specifies a data, control, or general
 	;	    register mnemonic, respectively
 	    name -> [ltr|dec]*	    	     ; mnemonic of register/function
 	    val -> [dec|hex]	    	     ; register/function number (integer constant)

 	    funcdef -> frange flags fields
 	    	    	    	; bitfield range for opcode
 	    	    	    	; list of fields' formats
 	    fields -> field*
 	    field -> [','] ftype frange flags
 	    flags -> ['*' flagexpr]
 	    flagexpr -> '[' flagexpr ']'
 	    flagexpr -> val '|' flagexpr
 	    ftype -> [ type | 'immed' | 'addr' ]
 	; 'immed' specifies an immediate value; see grammar for "val" above
 	    	; 'addr' specifies a C identifier; name of symbol to be resolved at
 	;	    link time
 	    frange -> ':' val '-' val	; starting to ending bit positions, where
 	    	    	    	; where 0 is least significant bit
 	    frange -> (null)	    	; default range of 31-0 will be assumed

 	    comment -> [';'|'#'] [char]*
 	    char -> any printable character
 	    ltr -> ['a'..'z'|'A'..'Z']
 	    dec -> ['0'..'9']*	    	    	    	    	     ; value in decimal
 	    hex -> '0x'['0'..'9' | 'a'..'f' | 'A'..'F']*	; value in hexadecimal


 Examples
 ========

 Example 1:

 The table:

 	    p1 dreg d1 1	     ; data register "d1" for COP1 has value 1
 	    p1 creg c3 3	     ; ctrl register "c3" for COP1 has value 3
 	    p3 func fill 0x1f:24-20	      ; function "fill" for COP3 has value 31 and
 	    	    	; no fields

 will allow the assembler to accept the following coprocessor instructions:

 	    LWC1 d1,0x100 ($2)
 	    fill

 Here, the general purpose register "$2", and instruction "LWC1", are standard
 mnemonics built-in to the MIPS assembler.


 Example 2:

 The table:

 	    p3 dreg d3 3	     ; data register "d3" for COP3 has value 3
 	    p3 creg c2 22	     ; control register "c2" for COP3 has value 22
 	    p3 func fee 0x1f:24-20 dreg:17-13 creg:12-8 immed:7-0
 	    	; function "fee" for COP3 has value 31, and 3 fields
 	    	; consisting of a data register, a control register,
 	    	; and an immediate value.

 will allow the assembler to accept the following coprocessor instruction:

 	    fee d3,c2,0x1

 and will emit the object code:

 	    31-26  25 24-20 19-18  17-13 12-8  7-0
 	    COPz   CO fun	    	      dreg  creg  immed
 	    010011 1  11111 00	     00011 10110 00000001

 	    0x4ff07601


 Example 3:

 The table:

 	    p3 dreg d3 3	     ; data register "d3" for COP3 has value 3
 	    p3 creg c2 22	     ; control register "c2" for COP3 has value 22
 	    p3 func fuu 0x01f00001 dreg:17-13 creg:12-8

 will allow the assembler to accept the following coprocessor
 instruction:

 	    fuu d3,c2

 and will emit the object code:

 	    31-26  25 24-20 19-18  17-13 12-8  7-0
 	    COPz   CO fun	    	      dreg  creg
 	    010011 1  11111 00	     00011 10110 00000001

 	    0x4ff07601

 In this way, the programmer can force arbitrary bits of an instruction
 to have predefined values.

 =======================================================================
 Additional notes:

 Encoding of ranges:
 To handle more than one bit position range within an instruction,
 use 0s to mask out the ranges which don't apply.
 May decide to modify the syntax to allow commas separate multiple
 ranges within an instruction (range','range).

 Changes in grammar:
 	The number of parms argument to the function entry
 was deleted from the original format such that we now count the fields.

 ----
 FIXME! should really change lexical analyzer
 to recognize 'dreg' etc. in context sensitive way.
 Currently function names or mnemonics may be incorrectly parsed as keywords

 FIXME! hex is ambiguous with any digit

 */

 #include "as.h"
 #include "itbl-lex.h"
 #include "itbl-ops.h"

 /* #define DEBUG */

 #ifdef DEBUG
 #ifndef DBG_LVL
 #define DBG_LVL 1
 #endif
 #else
 #define DBG_LVL 0
 #endif

 #if DBG_LVL >= 1
 #define DBG(x) printf x
 #else
 #define DBG(x)
 #endif

 #if DBG_LVL >= 2
 #define DBGL2(x) printf x
 #else
 #define DBGL2(x)
 #endif

 static int sbit, ebit;
 static struct itbl_entry *insn=0;
 static int yyerror (const char *);

 %}

 %union
   {
     char *str;
     int num;
     int processor;
     unsigned long val;
   }

 %token	    DREG CREG GREG IMMED ADDR INSN NUM ID NL PNUM
 %type	    <val> value flags flagexpr
 %type	    <num> number NUM ftype regtype pnum PNUM
 %type	    <str> ID name

 %start insntbl

 %%

 insntbl:
 	entrys
 	;

 entrys:
 	entry entrys
 	|
 	;

 entry:
 	pnum regtype name value NL
 	  {
 	    DBG (("line %d: entry pnum=%d type=%d name=%s value=x%x\n",
 	    	    insntbl_line, $1, $2, $3, $4));
 	    itbl_add_reg ($1, $2, $3, $4);
 	  }
 	| pnum INSN name value range flags
 	  {
 	    DBG (("line %d: entry pnum=%d type=INSN name=%s value=x%x",
 	    	    insntbl_line, $1, $3, $4));
 	    DBG ((" sbit=%d ebit=%d flags=0x%x\n", sbit, ebit, $6));
 	    insn=itbl_add_insn ($1, $3, $4, sbit, ebit, $6);
 	  }
 	fieldspecs NL
 	  {}
 	| NL
 	| error NL
 	;

 fieldspecs:
 	',' fieldspec fieldspecs
 	| fieldspec fieldspecs
 	|
 	;

 ftype:
 	regtype
 	  {
 	    DBGL2 (("ftype\n"));
 	    $$ = $1;
 	  }
 	| ADDR
 	  {
 	    DBGL2 (("addr\n"));
 	    $$ = ADDR;
 	  }
 	| IMMED
 	  {
 	    DBGL2 (("immed\n"));
 	    $$ = IMMED;
 	  }
 	;

 fieldspec:
 	ftype range flags
 	  {
 	    DBG (("line %d: field type=%d sbit=%d ebit=%d, flags=0x%x\n",
 	    	    insntbl_line, $1, sbit, ebit, $3));
 	    itbl_add_operand (insn, $1, sbit, ebit, $3);
 	  }
 	;

 flagexpr:
 	NUM '|' flagexpr
 	  {
 	    $$ = $1 | $3;
 	  }
 	| '[' flagexpr ']'
 	  {
 	    $$ = $2;
 	  }
 	| NUM
 	  {
 	    $$ = $1;
 	  }
 	;

 flags:
 	'*' flagexpr
 	  {
 	    DBGL2 (("flags=%d\n", $2));
 	    $$ = $2;
 	  }
 	|
 	  {
 	    $$ = 0;
 	  }
 	;

 range:
 	':' NUM '-' NUM
 	  {
 	    DBGL2 (("range %d %d\n", $2, $4));
 	    sbit = $2;
 	    ebit = $4;
 	  }
 	|
 	  {
 	    sbit = 31;
 	    ebit = 0;
 	  }
 	;

 pnum:
 	PNUM
 	  {
 	    DBGL2 (("pnum=%d\n",$1));
 	    $$ = $1;
 	  }
 	;

 regtype:
 	     DREG
 	  {
 	    DBGL2 (("dreg\n"));
 	    $$ = DREG;
 	  }
 	| CREG
 	  {
 	    DBGL2 (("creg\n"));
 	    $$ = CREG;
 	  }
 	| GREG
 	  {
 	    DBGL2 (("greg\n"));
 	    $$ = GREG;
 	  }
 	;

 name:
 	ID
 	  {
 	    DBGL2 (("name=%s\n",$1));
 	    $$ = $1;
 	  }
 	;

 number:
 	NUM
 	  {
 	    DBGL2 (("num=%d\n",$1));
 	    $$ = $1;
 	  }
 	;

 value:
 	NUM
 	  {
 	    DBGL2 (("val=x%x\n",$1));
 	    $$ = $1;
 	  }
 	;
 %%

 static int
 yyerror (const char *msg)
 {
   printf ("line %d: %s\n", insntbl_line, msg);
   return 0;
 }
	/* itbl-parse.y
	Copyright (C) 1997-2020 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. */

	%{

	/*

	Yacc grammar for instruction table entries.

	=======================================================================
	Original Instruction table specification document:

	MIPS Coprocessor Table Specification
	====================================

	This document describes the format of the MIPS coprocessor table. The
	table specifies a list of valid functions, data registers and control
	registers that can be used in coprocessor instructions. This list,
	together with the coprocessor instruction classes listed below,
	specifies the complete list of coprocessor instructions that will
	be recognized and assembled by the GNU assembler. In effect,
	this makes the GNU assembler table-driven, where the table is
	specified by the programmer.

	The table is an ordinary text file that the GNU assembler reads when
	it starts. Using the information in the table, the assembler
	generates an internal list of valid coprocessor registers and
	functions. The assembler uses this internal list in addition to the
	standard MIPS registers and instructions which are built-in to the
	assembler during code generation.

	To specify the coprocessor table when invoking the GNU assembler, use
	the command line option "--itbl file", where file is the
	complete name of the table, including path and extension.

	Examples:

	gas -t cop.tbl test.s -o test.o
	gas -t /usr/local/lib/cop.tbl test.s -o test.o
	gas --itbl d:\gnu\data\cop.tbl test.s -o test.o

	Only one table may be supplied during a single invocation of
	the assembler.


	Instruction classes
	===================

	Below is a list of the valid coprocessor instruction classes for
	any given coprocessor "z". These instructions are already recognized
	by the assembler, and are listed here only for reference.

	Class format instructions
	-------------------------------------------------
	Class1:
	op base rt offset
	LWCz rt,offset (base)
	SWCz rt,offset (base)
	Class2:
	COPz sub rt rd 0
	MTCz rt,rd
	MFCz rt,rd
	CTCz rt,rd
	CFCz rt,rd
	Class3:
	COPz CO cofun
	COPz cofun
	Class4:
	COPz BC br offset
	BCzT offset
	BCzF offset
	Class5:
	COPz sub rt rd 0
	DMFCz rt,rd
	DMTCz rt,rd
	Class6:
	op base rt offset
	LDCz rt,offset (base)
	SDCz rt,offset (base)
	Class7:
	COPz BC br offset
	BCzTL offset
	BCzFL offset

	The coprocessor table defines coprocessor-specific registers that can
	be used with all of the above classes of instructions, where
	appropriate. It also defines additional coprocessor-specific
	functions for Class3 (COPz cofun) instructions, Thus, the table allows
	the programmer to use convenient mnemonics and operands for these
	functions, instead of the COPz mmenmonic and cofun operand.

	The names of the MIPS general registers and their aliases are defined
	by the assembler and will be recognized as valid register names by the
	assembler when used (where allowed) in coprocessor instructions.
	However, the names and values of all coprocessor data and control
	register mnemonics must be specified in the coprocessor table.


	Table Grammar
	=============

	Here is the grammar for the coprocessor table:

	table -> entry*

	entry -> [z entrydef] [comment] '\n'

	entrydef -> type name val
	entrydef -> 'insn' name val funcdef ; type of entry (instruction)

	z -> 'p'['0'..'3'] ; processor number
	type -> ['dreg' \| 'creg' \| 'greg' ] ; type of entry (register)
	; 'dreg', 'creg' or 'greg' specifies a data, control, or general
	; register mnemonic, respectively
	name -> [ltr\|dec]* ; mnemonic of register/function
	val -> [dec\|hex] ; register/function number (integer constant)

	funcdef -> frange flags fields
	; bitfield range for opcode
	; list of fields' formats
	fields -> field*
	field -> [','] ftype frange flags
	flags -> ['*' flagexpr]
	flagexpr -> '[' flagexpr ']'
	flagexpr -> val '\|' flagexpr
	ftype -> [ type \| 'immed' \| 'addr' ]
	; 'immed' specifies an immediate value; see grammar for "val" above
	; 'addr' specifies a C identifier; name of symbol to be resolved at
	; link time
	frange -> ':' val '-' val ; starting to ending bit positions, where
	; where 0 is least significant bit
	frange -> (null) ; default range of 31-0 will be assumed

	comment -> [';'\|'#'] [char]*
	char -> any printable character
	ltr -> ['a'..'z'\|'A'..'Z']
	dec -> ['0'..'9']* ; value in decimal
	hex -> '0x'['0'..'9' \| 'a'..'f' \| 'A'..'F']* ; value in hexadecimal


	Examples
	========

	Example 1:

	The table:

	p1 dreg d1 1 ; data register "d1" for COP1 has value 1
	p1 creg c3 3 ; ctrl register "c3" for COP1 has value 3
	p3 func fill 0x1f:24-20 ; function "fill" for COP3 has value 31 and
	; no fields

	will allow the assembler to accept the following coprocessor instructions:

	LWC1 d1,0x100 ($2)
	fill

	Here, the general purpose register "$2", and instruction "LWC1", are standard
	mnemonics built-in to the MIPS assembler.


	Example 2:

	The table:

	p3 dreg d3 3 ; data register "d3" for COP3 has value 3
	p3 creg c2 22 ; control register "c2" for COP3 has value 22
	p3 func fee 0x1f:24-20 dreg:17-13 creg:12-8 immed:7-0
	; function "fee" for COP3 has value 31, and 3 fields
	; consisting of a data register, a control register,
	; and an immediate value.

	will allow the assembler to accept the following coprocessor instruction:

	fee d3,c2,0x1

	and will emit the object code:

	31-26 25 24-20 19-18 17-13 12-8 7-0
	COPz CO fun dreg creg immed
	010011 1 11111 00 00011 10110 00000001

	0x4ff07601


	Example 3:

	The table:

	p3 dreg d3 3 ; data register "d3" for COP3 has value 3
	p3 creg c2 22 ; control register "c2" for COP3 has value 22
	p3 func fuu 0x01f00001 dreg:17-13 creg:12-8

	will allow the assembler to accept the following coprocessor
	instruction:

	fuu d3,c2

	and will emit the object code:

	31-26 25 24-20 19-18 17-13 12-8 7-0
	COPz CO fun dreg creg
	010011 1 11111 00 00011 10110 00000001

	0x4ff07601

	In this way, the programmer can force arbitrary bits of an instruction
	to have predefined values.

	=======================================================================
	Additional notes:

	Encoding of ranges:
	To handle more than one bit position range within an instruction,
	use 0s to mask out the ranges which don't apply.
	May decide to modify the syntax to allow commas separate multiple
	ranges within an instruction (range','range).

	Changes in grammar:
	The number of parms argument to the function entry
	was deleted from the original format such that we now count the fields.

	----
	FIXME! should really change lexical analyzer
	to recognize 'dreg' etc. in context sensitive way.
	Currently function names or mnemonics may be incorrectly parsed as keywords

	FIXME! hex is ambiguous with any digit

	*/

	#include "as.h"
	#include "itbl-lex.h"
	#include "itbl-ops.h"

	/* #define DEBUG */

	#ifdef DEBUG
	#ifndef DBG_LVL
	#define DBG_LVL 1
	#endif
	#else
	#define DBG_LVL 0
	#endif

	#if DBG_LVL >= 1
	#define DBG(x) printf x
	#else
	#define DBG(x)
	#endif

	#if DBG_LVL >= 2
	#define DBGL2(x) printf x
	#else
	#define DBGL2(x)
	#endif

	static int sbit, ebit;
	static struct itbl_entry *insn=0;
	static int yyerror (const char *);

	%}

	%union
	{
	char *str;
	int num;
	int processor;
	unsigned long val;
	}

	%token DREG CREG GREG IMMED ADDR INSN NUM ID NL PNUM
	%type <val> value flags flagexpr
	%type <num> number NUM ftype regtype pnum PNUM
	%type <str> ID name

	%start insntbl

	%%

	insntbl:
	entrys
	;

	entrys:
	entry entrys
	\|
	;

	entry:
	pnum regtype name value NL
	{
	DBG (("line %d: entry pnum=%d type=%d name=%s value=x%x\n",
	insntbl_line, $1, $2, $3, $4));
	itbl_add_reg ($1, $2, $3, $4);
	}
	\| pnum INSN name value range flags
	{
	DBG (("line %d: entry pnum=%d type=INSN name=%s value=x%x",
	insntbl_line, $1, $3, $4));
	DBG ((" sbit=%d ebit=%d flags=0x%x\n", sbit, ebit, $6));
	insn=itbl_add_insn ($1, $3, $4, sbit, ebit, $6);
	}
	fieldspecs NL
	{}
	\| NL
	\| error NL
	;

	fieldspecs:
	',' fieldspec fieldspecs
	\| fieldspec fieldspecs
	\|
	;

	ftype:
	regtype
	{
	DBGL2 (("ftype\n"));
	$$ = $1;
	}
	\| ADDR
	{
	DBGL2 (("addr\n"));
	$$ = ADDR;
	}
	\| IMMED
	{
	DBGL2 (("immed\n"));
	$$ = IMMED;
	}
	;

	fieldspec:
	ftype range flags
	{
	DBG (("line %d: field type=%d sbit=%d ebit=%d, flags=0x%x\n",
	insntbl_line, $1, sbit, ebit, $3));
	itbl_add_operand (insn, $1, sbit, ebit, $3);
	}
	;

	flagexpr:
	NUM '\|' flagexpr
	{
	$$ = $1 \| $3;
	}
	\| '[' flagexpr ']'
	{
	$$ = $2;
	}
	\| NUM
	{
	$$ = $1;
	}
	;

	flags:
	'*' flagexpr
	{
	DBGL2 (("flags=%d\n", $2));
	$$ = $2;
	}
	\|
	{
	$$ = 0;
	}
	;

	range:
	':' NUM '-' NUM
	{
	DBGL2 (("range %d %d\n", $2, $4));
	sbit = $2;
	ebit = $4;
	}
	\|
	{
	sbit = 31;
	ebit = 0;
	}
	;

	pnum:
	PNUM
	{
	DBGL2 (("pnum=%d\n",$1));
	$$ = $1;
	}
	;

	regtype:
	DREG
	{
	DBGL2 (("dreg\n"));
	$$ = DREG;
	}
	\| CREG
	{
	DBGL2 (("creg\n"));
	$$ = CREG;
	}
	\| GREG
	{
	DBGL2 (("greg\n"));
	$$ = GREG;
	}
	;

	name:
	ID
	{
	DBGL2 (("name=%s\n",$1));
	$$ = $1;
	}
	;

	number:
	NUM
	{
	DBGL2 (("num=%d\n",$1));
	$$ = $1;
	}
	;

	value:
	NUM
	{
	DBGL2 (("val=x%x\n",$1));
	$$ = $1;
	}
	;
	%%

	static int
	yyerror (const char *msg)
	{
	printf ("line %d: %s\n", insntbl_line, msg);
	return 0;
	}