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mawk/parse.y
Thomas E. Dickey 7809cd0d7a
snapshot of project "mawk", label t20240819
2024-08-20 00:21:43 +00:00

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/********************************************
parse.y
copyright 2008-2020,2023, Thomas E. Dickey
copyright 1991-1994,1995, Michael D. Brennan
This is a source file for mawk, an implementation of
the AWK programming language.
Mawk is distributed without warranty under the terms of
the GNU General Public License, version 2, 1991.
********************************************/
/*
* $MawkId: parse.y,v 1.37 2024/07/26 20:14:00 tom Exp $
*/
%{
#include <mawk.h>
#include <symtype.h>
#include <code.h>
#include <memory.h>
#include <bi_funct.h>
#include <bi_vars.h>
#include <jmp.h>
#include <field.h>
#include <files.h>
#define YYMAXDEPTH 200
#if defined(YYBYACC) && (YYBYACC < 2)
extern int yylex(void);
#endif
extern void eat_nl(void);
static SYMTAB *save_arglist(const char *);
static int init_arglist(void);
static void RE_as_arg(void);
static void check_array(SYMTAB *);
static void check_var(SYMTAB *);
static void code_array(SYMTAB *);
static void code_call_id(CA_REC *, SYMTAB *);
static void field_A2I(void);
static void free_arglist(void);
static void improve_arglist(const char *);
static void resize_fblock(FBLOCK *);
static void switch_code_to_main(void);
static int scope;
static FBLOCK *active_funct;
static CA_REC *active_arglist;
/* when scope is SCOPE_FUNCT */
#define code_address(x) if( is_local(x) ) \
code2op(L_PUSHA, (x)->offset) ;\
else code2(_PUSHA, (x)->stval.cp)
#define CDP(x) (code_base+(x))
/* WARNING: These CDP() calculations become invalid after calls
that might change code_base. Which are: code2(), code2op(),
code_jmp() and code_pop().
*/
/* this nonsense caters to MSDOS large model */
#define CODE_FE_PUSHA() code_ptr->ptr = (PTR) 0 ; code1(FE_PUSHA)
%}
%union{
CELL *cp ;
SYMTAB *stp ;
int start ; /* code starting address as offset from code_base */
PF_CP fp ; /* ptr to a (print/printf) or (sub/gsub) function */
const BI_REC *bip ; /* ptr to info about a builtin */
FBLOCK *fbp ; /* ptr to a function block */
ARG2_REC *arg2p ;
CA_REC *ca_p ;
int ival ;
PTR ptr ;
}
/* two tokens to help with errors */
%token UNEXPECTED /* unexpected character */
%token BAD_DECIMAL
%token NL
%token SEMI_COLON
%token LBRACE RBRACE
%token LBOX RBOX
%token COMMA
%token <ival> IO_OUT /* > or output pipe */
%right ASSIGN ADD_ASG SUB_ASG MUL_ASG DIV_ASG MOD_ASG POW_ASG
%right QMARK COLON
%left OR
%left AND
%left IN
%left <ival> MATCH /* ~ or !~ */
%left EQ NEQ LT LTE GT GTE
%left CAT
%left GETLINE
%left PLUS MINUS
%left MUL DIV MOD
%left NOT UMINUS
%nonassoc IO_IN PIPE
%right POW
%left <ival> INC_or_DEC
%left DOLLAR FIELD /* last to remove a SR conflict
with getline */
%right LPAREN RPAREN /* removes some SR conflicts */
%token <ptr> DOUBLE STRING_ RE
%token <stp> ID D_ID
%token <fbp> FUNCT_ID
%token <bip> BUILTIN LENGTH
%token <cp> FIELD
%token PRINT PRINTF SPLIT MATCH_FUNC SUB GSUB
/* keywords */
%token DO WHILE FOR BREAK CONTINUE IF ELSE IN
%token DELETE BEGIN END EXIT NEXT NEXTFILE RETURN FUNCTION
%type <start> block block_or_separator
%type <start> statement_list statement mark
%type <ival> pr_args
%type <arg2p> arg2
%type <start> builtin
%type <start> getline_file
%type <start> lvalue field fvalue
%type <start> expr cat_expr p_expr
%type <start> while_front if_front
%type <start> for1 for2
%type <start> array_loop_front
%type <start> return_statement
%type <start> split_front re_arg sub_back
%type <ival> arglist args
%type <fp> print sub_or_gsub
%type <fbp> funct_start funct_head
%type <ca_p> call_args ca_front ca_back
%type <ival> f_arglist f_args
%%
/* productions */
program : program_block
| program program_block
;
program_block : PA_block /* pattern-action */
| function_def
| outside_error block
;
PA_block : block
{ /* this do nothing action removes a vacuous warning
from Bison */
}
| BEGIN
{ scope = SCOPE_BEGIN ; be_setup(scope) ; }
block
{ switch_code_to_main() ; }
| END
{ scope = SCOPE_END ; be_setup(scope) ; }
block
{ switch_code_to_main() ; }
| expr /* this works just like an if statement */
{ code_jmp(_JZ, (INST*)0) ; }
block_or_separator
{ patch_jmp( code_ptr ) ; }
/* range pattern, see comment in execute.c near _RANGE */
| expr COMMA
{
INST *p1 = CDP($1) ;
int len ;
code_push(p1, (unsigned) CodeOffset(p1), scope, active_funct) ;
code_ptr = p1 ;
code2op(_RANGE, 1) ;
code_ptr += 3 ;
len = (int) code_pop(code_ptr) ;
code_ptr += len ;
code1(_STOP) ;
p1 = CDP($1) ;
p1[2].op = CodeOffset(p1 + 1) ;
}
expr
{ code1(_STOP) ; }
block_or_separator
{
INST *p1 = CDP($1) ;
p1[3].op = (int) (CDP($6) - (p1 + 1)) ;
p1[4].op = CodeOffset(p1 + 1) ;
}
;
block : LBRACE statement_list RBRACE
{ $$ = $2 ; }
| LBRACE error RBRACE
{ $$ = code_offset ; /* does nothing won't be executed */
print_flag = getline_flag = paren_cnt = 0 ;
yyerrok ; }
;
block_or_separator : block
| separator /* default print action */
{ $$ = code_offset ;
code1(_PUSHINT) ; code1(0) ;
code2(_PRINT, bi_print) ;
}
;
statement_list : statement
| statement_list statement
;
statement : block
| expr separator
{ code1(_POP) ; }
| /* empty */ separator
{ $$ = code_offset ; }
| error separator
{ $$ = code_offset ;
print_flag = getline_flag = 0 ;
paren_cnt = 0 ;
yyerrok ;
}
| BREAK separator
{ $$ = code_offset ; BC_insert('B', code_ptr+1) ;
code2(_JMP, 0) /* don't use code_jmp ! */ ; }
| CONTINUE separator
{ $$ = code_offset ; BC_insert('C', code_ptr+1) ;
code2(_JMP, 0) ; }
| return_statement
{ if ( scope != SCOPE_FUNCT )
compile_error("return outside function body") ;
}
| NEXT separator
{ if ( scope != SCOPE_MAIN )
compile_error( "improper use of next" ) ;
$$ = code_offset ;
code1(_NEXT) ;
}
| NEXTFILE separator
{ if ( scope != SCOPE_MAIN )
compile_error( "improper use of nextfile" ) ;
$$ = code_offset ;
code1(_NEXTFILE) ;
}
;
separator : NL | SEMI_COLON
;
expr : cat_expr
| lvalue ASSIGN expr { code1(_ASSIGN) ; }
| lvalue ADD_ASG expr { code1(_ADD_ASG) ; }
| lvalue SUB_ASG expr { code1(_SUB_ASG) ; }
| lvalue MUL_ASG expr { code1(_MUL_ASG) ; }
| lvalue DIV_ASG expr { code1(_DIV_ASG) ; }
| lvalue MOD_ASG expr { code1(_MOD_ASG) ; }
| lvalue POW_ASG expr { code1(_POW_ASG) ; }
| expr EQ expr { code1(_EQ) ; }
| expr NEQ expr { code1(_NEQ) ; }
| expr LT expr { code1(_LT) ; }
| expr LTE expr { code1(_LTE) ; }
| expr GT expr { code1(_GT) ; }
| expr GTE expr { code1(_GTE) ; }
| expr MATCH expr
{
INST *p3 = CDP($3) ;
if ( p3 == code_ptr - 2 )
{
if ( p3->op == _MATCH0 ) p3->op = _MATCH1 ;
else /* check for string */
if ( p3->op == _PUSHS )
{ CELL *cp = ZMALLOC(CELL) ;
cp->type = C_STRING ;
cp->ptr = p3[1].ptr ;
cast_to_RE(cp) ;
no_leaks_re_ptr(cp->ptr) ;
code_ptr -= 2 ;
code2(_MATCH1, cp->ptr) ;
ZFREE(cp) ;
}
else code1(_MATCH2) ;
}
else code1(_MATCH2) ;
if ( !$2 ) code1(_NOT) ;
}
/* short circuit boolean evaluation */
| expr OR
{ code1(_TEST) ;
code_jmp(_LJNZ, (INST*)0) ;
}
expr
{ code1(_TEST) ; patch_jmp(code_ptr) ; }
| expr AND
{ code1(_TEST) ;
code_jmp(_LJZ, (INST*)0) ;
}
expr
{ code1(_TEST) ; patch_jmp(code_ptr) ; }
| expr QMARK { code_jmp(_JZ, (INST*)0) ; }
expr COLON { code_jmp(_JMP, (INST*)0) ; }
expr
{ patch_jmp(code_ptr) ; patch_jmp(CDP($7)) ; }
;
cat_expr : p_expr %prec CAT
| cat_expr p_expr %prec CAT
{ code1(_CAT) ; }
;
p_expr : DOUBLE
{ $$ = code_offset ; code2(_PUSHD, $1) ; }
| STRING_
{ $$ = code_offset ; code2(_PUSHS, $1) ; }
| ID %prec AND /* anything less than IN */
{ check_var($1) ;
$$ = code_offset ;
if ( is_local($1) )
{ code2op(L_PUSHI, $1->offset) ; }
else code2(_PUSHI, $1->stval.cp) ;
}
| LPAREN expr RPAREN
{ $$ = $2 ; }
;
p_expr : RE
{ $$ = code_offset ;
code2(_MATCH0, $1) ;
no_leaks_re_ptr($1);
}
;
p_expr : p_expr PLUS p_expr { code1(_ADD) ; }
| p_expr MINUS p_expr { code1(_SUB) ; }
| p_expr MUL p_expr { code1(_MUL) ; }
| p_expr DIV p_expr { code1(_DIV) ; }
| p_expr MOD p_expr { code1(_MOD) ; }
| p_expr POW p_expr { code1(_POW) ; }
| NOT p_expr
{ $$ = $2 ; code1(_NOT) ; }
| PLUS p_expr %prec UMINUS
{ $$ = $2 ; code1(_UPLUS) ; }
| MINUS p_expr %prec UMINUS
{ $$ = $2 ; code1(_UMINUS) ; }
| builtin
;
p_expr : ID INC_or_DEC
{ check_var($1) ;
$$ = code_offset ;
code_address($1) ;
if ( $2 == '+' ) code1(_POST_INC) ;
else code1(_POST_DEC) ;
}
| INC_or_DEC lvalue
{ $$ = $2 ;
if ( $1 == '+' ) code1(_PRE_INC) ;
else code1(_PRE_DEC) ;
}
;
p_expr : field INC_or_DEC
{ if ($2 == '+' ) code1(F_POST_INC ) ;
else code1(F_POST_DEC) ;
}
| INC_or_DEC field
{ $$ = $2 ;
if ( $1 == '+' ) code1(F_PRE_INC) ;
else code1( F_PRE_DEC) ;
}
;
lvalue : ID
{ $$ = code_offset ;
check_var($1) ;
code_address($1) ;
}
;
arglist : /* empty */
{ $$ = 0 ; }
| args
;
args : expr %prec LPAREN
{ $$ = 1 ; }
| args COMMA expr
{ $$ = $1 + 1 ; }
;
builtin :
BUILTIN mark LPAREN arglist RPAREN
{ const BI_REC *p = $1 ;
$$ = $2 ;
if ( (int)p->min_args > $4 || (int)p->max_args < $4 )
compile_error(
"wrong number of arguments in call to %s" ,
p->name ) ;
if ( p->min_args != p->max_args ) /* variable args */
{ code1(_PUSHINT) ; code1($4) ; }
code2(_BUILTIN , p->fp) ;
}
;
/* an empty production to store the code_ptr */
mark : /* empty */
{ $$ = code_offset ; }
;
/* print_statement */
statement : print mark pr_args pr_direction separator
{ code2(_PRINT, $1) ;
if ( $1 == bi_printf && $3 == 0 )
compile_error("no arguments in call to printf") ;
print_flag = 0 ;
$$ = $2 ;
}
;
print : PRINT { $$ = bi_print ; print_flag = 1 ;}
| PRINTF { $$ = bi_printf ; print_flag = 1 ; }
;
pr_args : arglist { code2op(_PUSHINT, $1) ; }
| LPAREN arg2 RPAREN
{ $$ = $2->cnt ; zfree($2,sizeof(ARG2_REC)) ;
code2op(_PUSHINT, $$) ;
}
| LPAREN RPAREN
{ $$=0 ; code2op(_PUSHINT, 0) ; }
;
arg2 : expr COMMA expr
{ $$ = ZMALLOC(ARG2_REC) ;
$$->start = $1 ;
$$->cnt = 2 ;
}
| arg2 COMMA expr
{ $$ = $1 ; $$->cnt++ ; }
;
pr_direction : /* empty */
| IO_OUT expr
{ code2op(_PUSHINT, $1) ; }
;
/* IF and IF-ELSE */
if_front : IF LPAREN expr RPAREN
{ $$ = $3 ; eat_nl() ; code_jmp(_JZ, (INST*)0) ; }
;
/* if_statement */
statement : if_front statement
{ patch_jmp( code_ptr ) ; }
;
else_back : ELSE { eat_nl() ; code_jmp(_JMP, (INST*)0) ; }
;
/* if_else_statement */
statement : if_front statement else_back statement
{ patch_jmp(code_ptr) ;
patch_jmp(CDP($4)) ;
}
;
/* LOOPS */
do : DO
{ eat_nl() ; BC_new() ; }
;
/* do_statement */
statement : do statement WHILE LPAREN expr RPAREN separator
{ $$ = $2 ;
code_jmp(_JNZ, CDP($2)) ;
BC_clear(code_ptr, CDP($5)) ; }
;
while_front : WHILE LPAREN expr RPAREN
{ eat_nl() ; BC_new() ;
$$ = $3 ;
/* check if const expression */
if ( code_ptr - 2 == CDP($3) &&
code_ptr[-2].op == _PUSHD &&
*(double*)code_ptr[-1].ptr != 0.0
)
code_ptr -= 2 ;
else
{ INST *p3 = CDP($3) ;
code_push(p3, (unsigned) CodeOffset(p3), scope, active_funct) ;
code_ptr = p3 ;
code2(_JMP, (INST*)0) ; /* code2() not code_jmp() */
}
}
;
/* while_statement */
statement : while_front statement
{
INST *p1 = CDP($1) ;
INST *p2 = CDP($2) ;
if ( p1 != p2 ) /* real test in loop */
{
int saved_offset ;
int len ;
p1[1].op = CodeOffset(p1 + 1) ;
saved_offset = code_offset ;
len = (int) code_pop(code_ptr) ;
code_ptr += len ;
code_jmp(_JNZ, CDP($2)) ;
BC_clear(code_ptr, CDP(saved_offset)) ;
}
else /* while(1) */
{
code_jmp(_JMP, p1) ;
BC_clear(code_ptr, CDP($2)) ;
}
}
;
/* for_statement */
statement : for1 for2 for3 statement
{
int cont_offset = code_offset ;
unsigned len = code_pop(code_ptr) ;
INST *p2 = CDP($2) ;
INST *p4 = CDP($4) ;
code_ptr += len ;
if ( p2 != p4 ) /* real test in for2 */
{
p4[-1].op = CodeOffset(p4 - 1) ;
len = code_pop(code_ptr) ;
code_ptr += len ;
code_jmp(_JNZ, CDP($4)) ;
}
else /* for(;;) */
code_jmp(_JMP, p4) ;
BC_clear(code_ptr, CDP(cont_offset)) ;
}
;
for1 : FOR LPAREN SEMI_COLON { $$ = code_offset ; }
| FOR LPAREN expr SEMI_COLON
{ $$ = $3 ; code1(_POP) ; }
;
for2 : SEMI_COLON { $$ = code_offset ; }
| expr SEMI_COLON
{
if ( code_ptr - 2 == CDP($1) &&
code_ptr[-2].op == _PUSHD &&
* (double*) code_ptr[-1].ptr != 0.0
)
code_ptr -= 2 ;
else
{
INST *p1 = CDP($1) ;
code_push(p1, (unsigned) CodeOffset(p1), scope, active_funct) ;
code_ptr = p1 ;
code2(_JMP, (INST*)0) ;
}
}
;
for3 : RPAREN
{ eat_nl() ; BC_new() ;
code_push((INST*)0,0, scope, active_funct) ;
}
| expr RPAREN
{ INST *p1 = CDP($1) ;
eat_nl() ; BC_new() ;
code1(_POP) ;
code_push(p1, (unsigned) CodeOffset(p1), scope, active_funct) ;
code_ptr -= code_ptr - p1 ;
}
;
/* arrays */
expr : expr IN ID
{ check_array($3) ;
code_array($3) ;
code1(A_TEST) ;
}
| LPAREN arg2 RPAREN IN ID
{ $$ = $2->start ;
code2op(A_CAT, $2->cnt) ;
zfree($2, sizeof(ARG2_REC)) ;
check_array($5) ;
code_array($5) ;
code1(A_TEST) ;
}
;
lvalue : ID mark LBOX args RBOX
{
if ( $4 > 1 )
{ code2op(A_CAT, $4) ; }
check_array($1) ;
if( is_local($1) )
{ code2op(LAE_PUSHA, $1->offset) ; }
else code2(AE_PUSHA, $1->stval.array) ;
$$ = $2 ;
}
;
p_expr : ID mark LBOX args RBOX %prec AND
{
if ( $4 > 1 )
{ code2op(A_CAT, $4) ; }
check_array($1) ;
if( is_local($1) )
{ code2op(LAE_PUSHI, $1->offset) ; }
else code2(AE_PUSHI, $1->stval.array) ;
$$ = $2 ;
}
| ID mark LBOX args RBOX INC_or_DEC
{
if ( $4 > 1 )
{ code2op(A_CAT,$4) ; }
check_array($1) ;
if( is_local($1) )
{ code2op(LAE_PUSHA, $1->offset) ; }
else code2(AE_PUSHA, $1->stval.array) ;
if ( $6 == '+' ) code1(_POST_INC) ;
else code1(_POST_DEC) ;
$$ = $2 ;
}
;
/* delete A[i] or delete A */
statement : DELETE ID mark LBOX args RBOX separator
{
$$ = $3 ;
if ( $5 > 1 ) { code2op(A_CAT, $5) ; }
check_array($2) ;
code_array($2) ;
code1(A_DEL) ;
}
| DELETE ID separator
{
$$ = code_offset ;
check_array($2) ;
code_array($2) ;
code1(DEL_A) ;
}
;
/* for ( i in A ) statement */
array_loop_front : FOR LPAREN ID IN ID RPAREN
{ eat_nl() ; BC_new() ;
$$ = code_offset ;
check_var($3) ;
code_address($3) ;
check_array($5) ;
code_array($5) ;
code2(SET_ALOOP, (INST*)0) ;
}
;
/* array_loop */
statement : array_loop_front statement
{
INST *p2 = CDP($2) ;
p2[-1].op = CodeOffset(p2 - 1) ;
BC_clear( code_ptr+2 , code_ptr) ;
code_jmp(ALOOP, p2) ;
code1(POP_AL) ;
}
;
/* fields
D_ID is a special token , same as an ID, but yylex()
only returns it after a '$'. In essence,
DOLLAR D_ID is really one token.
*/
field : FIELD
{ $$ = code_offset ; code2(F_PUSHA, $1) ; }
| DOLLAR D_ID
{ check_var($2) ;
$$ = code_offset ;
if ( is_local($2) )
{ code2op(L_PUSHI, $2->offset) ; }
else code2(_PUSHI, $2->stval.cp) ;
CODE_FE_PUSHA() ;
}
| DOLLAR D_ID mark LBOX args RBOX
{
if ( $5 > 1 )
{ code2op(A_CAT, $5) ; }
check_array($2) ;
if( is_local($2) )
{ code2op(LAE_PUSHI, $2->offset) ; }
else code2(AE_PUSHI, $2->stval.array) ;
CODE_FE_PUSHA() ;
$$ = $3 ;
}
| DOLLAR p_expr
{ $$ = $2 ; CODE_FE_PUSHA() ; }
| LPAREN field RPAREN
{ $$ = $2 ; }
;
p_expr : field %prec CAT /* removes field (++|--) sr conflict */
{ field_A2I() ; }
;
expr : field ASSIGN expr { code1(F_ASSIGN) ; }
| field ADD_ASG expr { code1(F_ADD_ASG) ; }
| field SUB_ASG expr { code1(F_SUB_ASG) ; }
| field MUL_ASG expr { code1(F_MUL_ASG) ; }
| field DIV_ASG expr { code1(F_DIV_ASG) ; }
| field MOD_ASG expr { code1(F_MOD_ASG) ; }
| field POW_ASG expr { code1(F_POW_ASG) ; }
;
/* split is handled different than a builtin because
it takes an array and optionally a regular expression as args */
p_expr : split_front split_back
{ code2(_BUILTIN, bi_split) ; }
;
split_front : SPLIT LPAREN expr COMMA ID
{ $$ = $3 ;
check_array($5) ;
code_array($5) ;
}
;
split_back : RPAREN
{ code2(_PUSHI, &fs_shadow) ; }
| COMMA expr RPAREN
{
if ( CDP($2) == code_ptr - 2 )
{
if ( code_ptr[-2].op == _MATCH0 ) {
RE_as_arg() ;
}
else
if ( code_ptr[-2].op == _PUSHS )
{ CELL *cp = ZMALLOC(CELL) ;
cp->type = C_STRING ;
cp->ptr = code_ptr[-1].ptr ;
cast_for_split(cp) ;
code_ptr[-2].op = _PUSHC ;
code_ptr[-1].ptr = (PTR) cp ;
no_leaks_cell(cp);
}
}
}
;
/* distinguish length vs length(string) vs length(array) */
p_expr : LENGTH LPAREN RPAREN
{ $$ = code_offset ;
code2(_PUSHI,field) ;
code2(_BUILTIN,bi_length) ;
}
| LENGTH LPAREN expr RPAREN
{ $$ = $3 ;
code2(_BUILTIN,bi_length) ;
}
| LENGTH LPAREN ID RPAREN
{
SYMTAB* stp = $3;
$$ = code_offset;
switch (stp->type) {
case ST_VAR:
code2(_PUSHI, stp->stval.cp);
code2(_BUILTIN, bi_length);
break;
case ST_ARRAY:
code2(A_PUSHA, stp->stval.array);
code2(_BUILTIN, bi_alength);
break;
case ST_LOCAL_VAR:
code2op(L_PUSHI, stp->offset);
code2(_BUILTIN, bi_length);
break;
case ST_LOCAL_ARRAY:
code2op(LA_PUSHA, stp->offset);
code2(_BUILTIN, bi_alength);
break;
case ST_NONE:
/* defer_alen */
code2(A_LENGTH, stp);
code2(_BUILTIN, bi_length);
break;
case ST_LOCAL_NONE:
/* defer_len */
{
DEFER_LEN* pi = ZMALLOC(DEFER_LEN);
pi->fbp = active_funct;
pi->offset = stp->offset;
code2(_LENGTH, pi);
code2(_BUILTIN, bi_length);
}
break;
default:
type_error(stp);
break;
}
}
;
p_expr : LENGTH %prec CAT /* fixes s/r conflict length vs length() */
{ $$ = code_offset ;
code2(_PUSHI,field) ;
code2(_BUILTIN,bi_length) ;
}
;
/* match(expr, RE) */
p_expr : MATCH_FUNC LPAREN expr COMMA re_arg RPAREN
{ $$ = $3 ;
code2(_BUILTIN, bi_match) ;
}
;
re_arg : expr
{
INST *p1 = CDP($1) ;
if ( p1 == code_ptr - 2 )
{
if ( p1->op == _MATCH0 ) RE_as_arg() ;
else
if ( p1->op == _PUSHS )
{ CELL *cp = ZMALLOC(CELL) ;
cp->type = C_STRING ;
cp->ptr = p1[1].ptr ;
cast_to_RE(cp) ;
p1->op = _PUSHC ;
p1[1].ptr = (PTR) cp ;
no_leaks_cell(cp);
}
}
}
;
/* exit_statement */
statement : EXIT separator
{ $$ = code_offset ;
code1(_EXIT0) ; }
| EXIT expr separator
{ $$ = $2 ; code1(_EXIT) ; }
;
return_statement : RETURN separator
{ $$ = code_offset ;
code1(_RET0) ; }
| RETURN expr separator
{ $$ = $2 ; code1(_RET) ; }
;
/* getline */
p_expr : getline %prec GETLINE
{ $$ = code_offset ;
code2(F_PUSHA, &field[0]) ;
code1(_PUSHINT) ; code1(0) ;
code2(_BUILTIN, bi_getline) ;
getline_flag = 0 ;
}
| getline fvalue %prec GETLINE
{ $$ = $2 ;
code1(_PUSHINT) ; code1(0) ;
code2(_BUILTIN, bi_getline) ;
getline_flag = 0 ;
}
| getline_file p_expr %prec IO_IN
{ code1(_PUSHINT) ; code1(F_IN) ;
code2(_BUILTIN, bi_getline) ;
/* getline_flag already off in yylex() */
}
| p_expr PIPE GETLINE
{ code2(F_PUSHA, &field[0]) ;
code1(_PUSHINT) ; code1(PIPE_IN) ;
code2(_BUILTIN, bi_getline) ;
}
| p_expr PIPE GETLINE fvalue
{
code1(_PUSHINT) ; code1(PIPE_IN) ;
code2(_BUILTIN, bi_getline) ;
}
;
getline : GETLINE { getline_flag = 1 ; } ;
fvalue : lvalue | field ;
getline_file : getline IO_IN
{ $$ = code_offset ;
code2(F_PUSHA, field+0) ;
}
| getline fvalue IO_IN
{ $$ = $2 ; }
;
/*==========================================
sub and gsub
==========================================*/
p_expr : sub_or_gsub LPAREN re_arg COMMA expr sub_back
{
INST *p5 = CDP($5) ;
INST *p6 = CDP($6) ;
if ( p6 - p5 == 2 && p5->op == _PUSHS )
{ /* cast from STRING to REPL at compile time */
CELL *cp = ZMALLOC(CELL) ;
cp->type = C_STRING ;
cp->ptr = p5[1].ptr ;
cast_to_REPL(cp) ;
p5->op = _PUSHC ;
p5[1].ptr = (PTR) cp ;
no_leaks_cell(cp);
}
code2(_BUILTIN, $1) ;
$$ = $3 ;
}
;
sub_or_gsub : SUB { $$ = bi_sub ; }
| GSUB { $$ = bi_gsub ; }
;
sub_back : RPAREN /* substitute into $0 */
{ $$ = code_offset ;
code2(F_PUSHA, &field[0]) ;
}
| COMMA fvalue RPAREN
{ $$ = $2 ; }
;
/*================================================
user defined functions
*=================================*/
function_def : funct_start block
{
resize_fblock($1) ;
restore_ids() ;
switch_code_to_main() ;
}
;
funct_start : funct_head LPAREN f_arglist RPAREN
{ eat_nl() ;
scope = SCOPE_FUNCT ;
active_funct = $1 ;
*main_code_p = active_code ;
$1->nargs = (NUM_ARGS) $3 ;
if ( $3 )
$1->typev = (SYM_TYPE *)
memset( zmalloc((size_t) $3), ST_LOCAL_NONE, (size_t) $3) ;
else $1->typev = (SYM_TYPE *) 0 ;
code_ptr = code_base =
(INST *) zmalloc(INST_BYTES(PAGESZ));
code_limit = code_base + PAGESZ ;
code_warn = code_limit - CODEWARN ;
improve_arglist($1->name);
free_arglist();
}
;
funct_head : FUNCTION ID
{ FBLOCK *fbp ;
if ( $2 == NULL )
{
compile_error("function definition") ;
mawk_exit(3);
}
if ( $2->type == ST_NONE )
{
$2->type = ST_FUNCT ;
fbp = $2->stval.fbp = ZMALLOC(FBLOCK) ;
fbp->name = $2->name ;
fbp->code = (INST*) 0 ;
}
else
{
type_error( $2 ) ;
/* this FBLOCK will not be put in
the symbol table */
fbp = ZMALLOC(FBLOCK) ;
fbp->name = "" ;
}
$$ = fbp ;
}
| FUNCTION FUNCT_ID
{ $$ = $2 ;
if ( $2->code )
compile_error("redefinition of %s" , $2->name) ;
}
;
f_arglist : /* empty */ { $$ = init_arglist() ; }
| f_args
;
f_args : ID
{ init_arglist();
$1 = save_arglist($1->name) ;
$1->offset = 0 ;
$$ = 1 ;
}
| f_args COMMA ID
{ if ( is_local($3) )
compile_error("%s is duplicated in argument list",
$3->name) ;
else
{ $3 = save_arglist($3->name) ;
$3->offset = (unsigned char) $1 ;
$$ = $1 + 1 ;
}
}
;
outside_error : error
{ /* we may have to recover from a bungled function
definition */
/* can have local ids, before code scope
changes */
restore_ids() ;
switch_code_to_main() ;
}
;
/* a call to a user defined function */
p_expr : FUNCT_ID mark call_args
{ $$ = $2 ;
code2(_CALL, $1) ;
if ( $3 ) code1($3->arg_num+1) ;
else code1(0) ;
check_fcall($1, scope, code_move_level, active_funct, $3) ;
}
;
call_args : LPAREN RPAREN
{ $$ = (CA_REC *) 0 ; }
| ca_front ca_back
{ $$ = $2 ;
$$->link = $1 ;
$$->arg_num = (NUM_ARGS) ($1 ? $1->arg_num+1 : 0) ;
$$->call_lineno = token_lineno;
}
;
/* The funny definition of ca_front with the COMMA bound to the ID is to
force a shift to avoid a reduce/reduce conflict
ID->id or ID->array
Or to avoid a decision, if the type of the ID has not yet been
determined
*/
ca_front : LPAREN
{ $$ = (CA_REC *) 0 ; }
| ca_front expr COMMA
{ $$ = ZMALLOC(CA_REC) ;
$$->link = $1 ;
$$->type = CA_EXPR ;
$$->arg_num = (NUM_ARGS) ($1 ? $1->arg_num+1 : 0) ;
$$->call_offset = code_offset ;
$$->call_lineno = token_lineno;
}
| ca_front ID COMMA
{ $$ = ZMALLOC(CA_REC) ;
$$->type = ST_NONE ;
$$->link = $1 ;
$$->arg_num = (NUM_ARGS) ($1 ? $1->arg_num+1 : 0) ;
$$->call_lineno = token_lineno;
code_call_id($$, $2) ;
}
;
ca_back : expr RPAREN
{ $$ = ZMALLOC(CA_REC) ;
$$->type = CA_EXPR ;
$$->call_offset = code_offset ;
}
| ID RPAREN
{ $$ = ZMALLOC(CA_REC) ;
$$->type = ST_NONE ;
code_call_id($$, $1) ;
}
;
%%
/*
* Check for special case where there is a forward reference to a newly
* declared function using an array parameter. Because the parameter
* mechanism for arrays uses a different byte code, we would like to know
* if this is the case so that the function's contents can handle the array
* type.
*/
static void
improve_arglist(const char *name)
{
CA_REC *p, *p2;
FCALL_REC *q;
TRACE(("improve_arglist(%s)\n", name));
for (p = active_arglist; p != 0; p = p->link) {
if (p->type == ST_LOCAL_NONE) {
for (q = resolve_list; q != 0; q = q->link) {
if (!strcmp(q->callee->name, name)) {
for (p2 = q->arg_list; p2 != 0; p2 = p2->link) {
if (p2->arg_num == p->arg_num) {
switch (p2->type) {
case ST_NONE:
case ST_LOCAL_NONE:
break;
default:
p->type = p2->type;
p->sym_p->type = p2->type;
TRACE(("...set arg %d of %s to %s\n",
p->arg_num + 1,
name,
type_to_str(p->type)));
break;
}
}
}
if (p->type != ST_LOCAL_NONE)
break;
}
}
if (p->type != ST_LOCAL_NONE)
break;
}
}
}
/* maintain data for f_arglist to make it visible in funct_start */
static int
init_arglist(void)
{
free_arglist();
return 0;
}
static SYMTAB *
save_arglist(const char *s)
{
SYMTAB *result = save_id(s);
CA_REC *saveit = ZMALLOC(CA_REC);
if (saveit != 0) {
CA_REC *p, *q;
int arg_num = 0;
for (p = active_arglist, q = 0; p != 0; q = p, p = p->link) {
++arg_num;
}
saveit->link = 0;
saveit->type = ST_LOCAL_NONE;
saveit->arg_num = (NUM_ARGS) arg_num;
saveit->call_lineno = token_lineno;
saveit->sym_p = result;
if (q != 0) {
q->link = saveit;
} else {
active_arglist = saveit;
}
}
return result;
}
static void
free_arglist(void)
{
while (active_arglist != 0) {
CA_REC *next = active_arglist->link;
ZFREE(active_arglist);
active_arglist = next;
}
}
/* resize the code for a user function */
static void
resize_fblock(FBLOCK * fbp)
{
CODEBLOCK *p = ZMALLOC(CODEBLOCK);
code2op(_RET0, _HALT);
/* make sure there is always a return */
*p = active_code;
fbp->code = code_shrink(p, &fbp->size);
/* code_shrink() zfrees p */
if (dump_code_flag)
add_to_fdump_list(fbp);
}
/* convert FE_PUSHA to FE_PUSHI
or F_PUSH to F_PUSHI
*/
static void
field_A2I(void)
{
if (code_ptr[-1].op == FE_PUSHA &&
code_ptr[-1].ptr == (PTR) 0) {
/* On most architectures, the two tests are the same; a good
compiler might eliminate one. On LM_DOS, and possibly other
segmented architectures, they are not */
code_ptr[-1].op = FE_PUSHI;
} else {
CELL *cp = (CELL *) code_ptr[-1].ptr;
if ((cp == field) || ((cp > NF) && (cp <= LAST_PFIELD))) {
code_ptr[-2].op = _PUSHI;
} else if (cp == NF) {
code_ptr[-2].op = NF_PUSHI;
code_ptr--;
} else {
code_ptr[-2].op = F_PUSHI;
code_ptr->op = field_addr_to_index(code_ptr[-1].ptr);
code_ptr++;
}
}
}
/* we've seen an ID in a context where it should be a VAR,
check that's consistent with previous usage */
static void
check_var(SYMTAB * p)
{
switch (p ? p->type : -1) {
case ST_NONE: /* new id */
p->type = ST_VAR;
p->stval.cp = ZMALLOC(CELL);
p->stval.cp->type = C_NOINIT;
break;
case ST_LOCAL_NONE:
p->type = ST_LOCAL_VAR;
active_funct->typev[p->offset] = ST_LOCAL_VAR;
break;
case ST_VAR:
case ST_LOCAL_VAR:
break;
default:
type_error(p);
break;
}
}
/* we've seen an ID in a context where it should be an ARRAY,
check that's consistent with previous usage */
static void
check_array(SYMTAB * p)
{
switch (p ? p->type : -1) {
case ST_NONE: /* a new array */
p->type = ST_ARRAY;
p->stval.array = new_ARRAY();
no_leaks_array(p->stval.array);
break;
case ST_ARRAY:
case ST_LOCAL_ARRAY:
break;
case ST_LOCAL_NONE:
p->type = ST_LOCAL_ARRAY;
active_funct->typev[p->offset] = ST_LOCAL_ARRAY;
break;
default:
type_error(p);
break;
}
}
static void
code_array(SYMTAB * p)
{
if (is_local(p))
code2op(LA_PUSHA, p->offset);
else
code2(A_PUSHA, p->stval.array);
}
/* we've seen an ID as an argument to a user defined function */
static void
code_call_id(CA_REC * p, SYMTAB * ip)
{
static CELL dummy;
p->call_offset = code_offset;
/* This always gets set now. So that fcall:relocate_arglist
works. */
switch (ip->type) {
case ST_VAR:
p->type = CA_EXPR;
code2(_PUSHI, ip->stval.cp);
break;
case ST_LOCAL_VAR:
p->type = CA_EXPR;
code2op(L_PUSHI, ip->offset);
break;
case ST_ARRAY:
p->type = CA_ARRAY;
code2(A_PUSHA, ip->stval.array);
break;
case ST_LOCAL_ARRAY:
p->type = CA_ARRAY;
code2op(LA_PUSHA, ip->offset);
break;
/* not enough info to code it now; it will have to
be patched later */
case ST_NONE:
p->type = ST_NONE;
p->sym_p = ip;
code2(_PUSHI, &dummy);
break;
case ST_LOCAL_NONE:
p->type = ST_LOCAL_NONE;
p->type_p = &active_funct->typev[ip->offset];
code2op(L_PUSHI, ip->offset);
break;
#ifdef DEBUG
default:
bozo("code_call_id");
#endif
}
}
/* an RE by itself was coded as _MATCH0 , change to
push as an expression */
static void
RE_as_arg(void)
{
CELL *cp = ZMALLOC(CELL);
code_ptr -= 2;
cp->type = C_RE;
cp->ptr = code_ptr[1].ptr;
code2(_PUSHC, cp);
no_leaks_cell_ptr(cp);
}
/* reset the active_code back to the MAIN block */
static void
switch_code_to_main(void)
{
switch (scope) {
case SCOPE_BEGIN:
*begin_code_p = active_code;
active_code = *main_code_p;
break;
case SCOPE_END:
*end_code_p = active_code;
active_code = *main_code_p;
break;
case SCOPE_FUNCT:
active_code = *main_code_p;
break;
case SCOPE_MAIN:
break;
}
active_funct = (FBLOCK *) 0;
scope = SCOPE_MAIN;
}
void
parse(void)
{
if (yyparse() || compile_error_count != 0)
mawk_exit(2);
scan_cleanup();
set_code();
/* code must be set before call to resolve_fcalls() */
if (resolve_list)
resolve_fcalls();
if (compile_error_count != 0)
mawk_exit(2);
if (dump_code_flag) {
dump_code();
mawk_exit(0);
}
}
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