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BSD 3 development
[unix-history] / usr / src / cmd / mip / cgram.y
%term NAME 2
%term STRING 3
%term ICON 4
%term FCON 5
%term PLUS 6
%term MINUS 8
%term MUL 11
%term AND 14
%term OR 17
%term ER 19
%term QUEST 21
%term COLON 22
%term ANDAND 23
%term OROR 24
/* special interfaces for yacc alone */
/* These serve as abbreviations of 2 or more ops:
ASOP =, = ops
RELOP LE,LT,GE,GT
EQUOP EQ,NE
DIVOP DIV,MOD
SHIFTOP LS,RS
ICOP ICR,DECR
UNOP NOT,COMPL
STROP DOT,STREF
*/
%term ASOP 25
%term RELOP 26
%term EQUOP 27
%term DIVOP 28
%term SHIFTOP 29
%term INCOP 30
%term UNOP 31
%term STROP 32
/* reserved words, etc */
%term TYPE 33
%term CLASS 34
%term STRUCT 35
%term RETURN 36
%term GOTO 37
%term IF 38
%term ELSE 39
%term SWITCH 40
%term BREAK 41
%term CONTINUE 42
%term WHILE 43
%term DO 44
%term FOR 45
%term DEFAULT 46
%term CASE 47
%term SIZEOF 48
%term ENUM 49
/* little symbols, etc. */
/* namely,
LP (
RP )
LC {
RC }
LB [
RB ]
CM ,
SM ;
*/
%term LP 50
%term RP 51
%term LC 52
%term RC 53
%term LB 54
%term RB 55
%term CM 56
%term SM 57
%term ASSIGN 58
/* at last count, there were 7 shift/reduce, 1 reduce/reduce conflicts
/* these involved:
if/else
recognizing functions in various contexts, including declarations
error recovery
*/
%left CM
%right ASOP ASSIGN
%right QUEST COLON
%left OROR
%left ANDAND
%left OR
%left ER
%left AND
%left EQUOP
%left RELOP
%left SHIFTOP
%left PLUS MINUS
%left MUL DIVOP
%right UNOP
%right INCOP SIZEOF
%left LB LP STROP
%{
# include "mfile1"
%}
/* define types */
%start ext_def_list
%type <intval> con_e ifelprefix ifprefix whprefix forprefix doprefix switchpart
enum_head str_head name_lp
%type <nodep> e .e term attributes oattributes type enum_dcl struct_dcl
cast_type null_decl funct_idn declarator fdeclarator nfdeclarator
elist
%token <intval> CLASS NAME STRUCT RELOP CM DIVOP PLUS MINUS SHIFTOP MUL AND OR ER ANDAND OROR
ASSIGN STROP INCOP UNOP ICON
%token <nodep> TYPE
%%
%{
static int fake = 0;
static char fakename[NCHNAM+1];
%}
ext_def_list: ext_def_list external_def
|
=ftnend();
;
external_def: data_def
={ curclass = SNULL; blevel = 0; }
| error
={ curclass = SNULL; blevel = 0; }
;
data_def:
oattributes SM
={ $1->op = FREE; }
| oattributes init_dcl_list SM
={ $1->op = FREE; }
| oattributes fdeclarator {
defid( tymerge($1,$2), curclass==STATIC?STATIC:EXTDEF );
#ifndef LINT
pfstab(stab[$2->rval].sname);
#endif
} function_body
={
if( blevel ) cerror( "function level error" );
if( reached ) retstat |= NRETVAL;
$1->op = FREE;
ftnend();
}
;
function_body: arg_dcl_list compoundstmt
;
arg_dcl_list: arg_dcl_list declaration
| ={ blevel = 1; }
;
stmt_list: stmt_list statement
| /* empty */
={ bccode();
locctr(PROG);
}
;
r_dcl_stat_list : dcl_stat_list attributes SM
={ $2->op = FREE;
#ifndef LINT
plcstab(blevel);
#endif
}
| dcl_stat_list attributes init_dcl_list SM
={ $2->op = FREE;
#ifndef LINT
plcstab(blevel);
#endif
}
;
dcl_stat_list : dcl_stat_list attributes SM
={ $2->op = FREE; }
| dcl_stat_list attributes init_dcl_list SM
={ $2->op = FREE; }
| /* empty */
;
declaration: attributes declarator_list SM
={ curclass = SNULL; $1->op = FREE; }
| attributes SM
={ curclass = SNULL; $1->op = FREE; }
| error SM
={ curclass = SNULL; }
;
oattributes: attributes
| /* VOID */
={ $$ = mkty(INT,0,INT); curclass = SNULL; }
;
attributes: class type
={ $$ = $2; }
| type class
| class
={ $$ = mkty(INT,0,INT); }
| type
={ curclass = SNULL ; }
;
class: CLASS
={ curclass = $1; }
;
type: TYPE
| TYPE TYPE
={ $1->type = types( $1->type, $2->type, UNDEF );
$2->op = FREE;
}
| TYPE TYPE TYPE
={ $1->type = types( $1->type, $2->type, $3->type );
$2->op = $3->op = FREE;
}
| struct_dcl
| enum_dcl
;
enum_dcl: enum_head LC moe_list optcomma RC
={ $$ = dclstruct($1); }
| ENUM NAME
={ $$ = rstruct($2,0); stwart = instruct; }
;
enum_head: ENUM
={ $$ = bstruct(-1,0); }
| ENUM NAME
={ $$ = bstruct($2,0); }
;
moe_list: moe
| moe_list CM moe
;
moe: NAME
={ moedef( $1 ); }
| NAME ASSIGN con_e
={ strucoff = $3; moedef( $1 ); }
;
struct_dcl: str_head LC type_dcl_list optsemi RC
={ $$ = dclstruct($1); }
| STRUCT NAME
={ $$ = rstruct($2,$1); }
;
str_head: STRUCT
={ $$ = bstruct(-1,$1); stwart=0; }
| STRUCT NAME
={ $$ = bstruct($2,$1); stwart=0; }
;
type_dcl_list: type_declaration
| type_dcl_list SM type_declaration
;
type_declaration: type declarator_list
={ curclass = SNULL; stwart=0; $1->op = FREE; }
| type
={ if( curclass != MOU ){
curclass = SNULL;
}
else {
sprintf( fakename, "$%dFAKE", fake++ );
defid( tymerge($1, bdty(NAME,NIL,lookup( fakename, SMOS ))), curclass );
}
stwart = 0;
$1->op = FREE;
}
;
declarator_list: declarator
={ defid( tymerge($<nodep>0,$1), curclass); stwart = instruct; }
| declarator_list CM {$<nodep>$=$<nodep>0;} declarator
={ defid( tymerge($<nodep>0,$4), curclass); stwart = instruct; }
;
declarator: fdeclarator
| nfdeclarator
| nfdeclarator COLON con_e
%prec CM
={ if( !(instruct&INSTRUCT) ) uerror( "field outside of structure" );
if( $3<0 || $3 >= FIELD ){
uerror( "illegal field size" );
$3 = 1;
}
defid( tymerge($<nodep>0,$1), FIELD|$3 );
$$ = NIL;
}
| COLON con_e
%prec CM
={ if( !(instruct&INSTRUCT) ) uerror( "field outside of structure" );
falloc( stab, $2, -1, $<nodep>0 ); /* alignment or hole */
$$ = NIL;
}
| error
={ $$ = NIL; }
;
/* int (a)(); is not a function --- sorry! */
nfdeclarator: MUL nfdeclarator
={ umul:
$$ = bdty( UNARY MUL, $2, 0 ); }
| nfdeclarator LP RP
={ uftn:
$$ = bdty( UNARY CALL, $1, 0 ); }
| nfdeclarator LB RB
={ uary:
$$ = bdty( LB, $1, 0 ); }
| nfdeclarator LB con_e RB
={ bary:
if( (int)$3 <= 0 ) werror( "zero or negative subscript" );
$$ = bdty( LB, $1, $3 ); }
| NAME
={ $$ = bdty( NAME, NIL, $1 ); }
| LP nfdeclarator RP
={ $$=$2; }
;
fdeclarator: MUL fdeclarator
={ goto umul; }
| fdeclarator LP RP
={ goto uftn; }
| fdeclarator LB RB
={ goto uary; }
| fdeclarator LB con_e RB
={ goto bary; }
| LP fdeclarator RP
={ $$ = $2; }
| name_lp name_list RP
={
if( blevel!=0 ) uerror("function declaration in bad context");
$$ = bdty( UNARY CALL, bdty(NAME,NIL,$1), 0 );
stwart = 0;
}
| name_lp RP
={
$$ = bdty( UNARY CALL, bdty(NAME,NIL,$1), 0 );
stwart = 0;
}
;
name_lp: NAME LP
={
/* turn off typedefs for argument names */
stwart = SEENAME;
}
;
name_list: NAME
={ ftnarg( $1 ); stwart = SEENAME; }
| name_list CM NAME
={ ftnarg( $3 ); stwart = SEENAME; }
;
/* always preceeded by attributes: thus the $<nodep>0's */
init_dcl_list: init_declarator
%prec CM
| init_dcl_list CM {$<nodep>$=$<nodep>0;} init_declarator
;
/* always preceeded by attributes */
xnfdeclarator: nfdeclarator
={ defid( $1 = tymerge($<nodep>0,$1), curclass);
beginit($1->rval);
}
| error
;
/* always preceeded by attributes */
init_declarator: nfdeclarator
={ nidcl( tymerge($<nodep>0,$1) ); }
| fdeclarator
={ defid( tymerge($<nodep>0,$1), uclass(curclass) );
}
| xnfdeclarator optasgn e
%prec CM
={ doinit( $3 );
endinit(); }
| xnfdeclarator optasgn LC init_list optcomma RC
={ endinit(); }
;
init_list: initializer
%prec CM
| init_list CM initializer
;
initializer: e
%prec CM
={ doinit( $1 ); }
| ibrace init_list optcomma RC
={ irbrace(); }
;
optcomma : /* VOID */
| CM
;
optsemi : /* VOID */
| SM
;
optasgn : /* VOID */
={ werror( "old-fashioned initialization: use =" ); }
| ASSIGN
;
ibrace : LC
={ ilbrace(); }
;
/* STATEMENTS */
compoundstmt: dcmpstmt
| cmpstmt
;
dcmpstmt: begin r_dcl_stat_list stmt_list RC
={
#ifndef LINT
prcstab(blevel);
#endif
--blevel;
if( blevel == 1 ) blevel = 0;
clearst( blevel );
checkst( blevel );
autooff = *--psavbc;
regvar = *--psavbc;
}
;
cmpstmt: begin stmt_list RC
={ --blevel;
if( blevel == 1 ) blevel = 0;
clearst( blevel );
checkst( blevel );
autooff = *--psavbc;
regvar = *--psavbc;
}
;
begin: LC
={ if( blevel == 1 ) dclargs();
++blevel;
if( psavbc > &asavbc[BCSZ-2] ) cerror( "nesting too deep" );
*psavbc++ = regvar;
*psavbc++ = autooff;
}
;
statement: e SM
={ ecomp( $1 ); }
| compoundstmt
| ifprefix statement
={ deflab($1);
reached = 1;
}
| ifelprefix statement
={ if( $1 != NOLAB ){
deflab( $1 );
reached = 1;
}
}
| whprefix statement
={ branch( contlab );
deflab( brklab );
if( (flostat&FBRK) || !(flostat&FLOOP)) reached = 1;
else reached = 0;
resetbc(0);
}
| doprefix statement WHILE LP e RP SM
={ deflab( contlab );
if( flostat & FCONT ) reached = 1;
ecomp( buildtree( CBRANCH, buildtree( NOT, $5, NIL ), bcon( $1 ) ) );
deflab( brklab );
reached = 1;
resetbc(0);
}
| forprefix .e RP statement
={ deflab( contlab );
if( flostat&FCONT ) reached = 1;
if( $2 ) ecomp( $2 );
branch( $1 );
deflab( brklab );
if( (flostat&FBRK) || !(flostat&FLOOP) ) reached = 1;
else reached = 0;
resetbc(0);
}
| switchpart statement
={ if( reached ) branch( brklab );
deflab( $1 );
swend();
deflab(brklab);
if( (flostat&FBRK) || !(flostat&FDEF) ) reached = 1;
resetbc(FCONT);
}
| BREAK SM
={ if( brklab == NOLAB ) uerror( "illegal break");
else if(reached) branch( brklab );
flostat |= FBRK;
if( brkflag ) goto rch;
reached = 0;
}
| CONTINUE SM
={ if( contlab == NOLAB ) uerror( "illegal continue");
else branch( contlab );
flostat |= FCONT;
goto rch;
}
| RETURN SM
={ retstat |= NRETVAL;
branch( retlab );
rch:
if( !reached ) werror( "statement not reached");
reached = 0;
}
| RETURN e SM
={ register NODE *temp;
idname = curftn;
temp = buildtree( NAME, NIL, NIL );
temp->type = DECREF( temp->type );
temp = buildtree( RETURN, temp, $2 );
/* now, we have the type of the RHS correct */
temp->left->op = FREE;
temp->op = FREE;
ecomp( buildtree( FORCE, temp->right, NIL ) );
retstat |= RETVAL;
branch( retlab );
reached = 0;
}
| GOTO NAME SM
={ register NODE *q;
q = block( FREE, NIL, NIL, INT|ARY, 0, INT );
q->rval = idname = $2;
defid( q, ULABEL );
stab[idname].suse = -lineno;
branch( stab[idname].offset );
goto rch;
}
| SM
| error SM
| error RC
| label statement
;
label: NAME COLON
={ register NODE *q;
q = block( FREE, NIL, NIL, INT|ARY, 0, LABEL );
q->rval = $1;
defid( q, LABEL );
reached = 1;
}
| CASE e COLON
={ addcase($2);
reached = 1;
}
| DEFAULT COLON
={ reached = 1;
adddef();
flostat |= FDEF;
}
;
doprefix: DO
={ savebc();
if( !reached ) werror( "loop not entered at top");
brklab = getlab();
contlab = getlab();
deflab( $$ = getlab() );
reached = 1;
}
;
ifprefix: IF LP e RP
={ ecomp( buildtree( CBRANCH, $3, bcon( $$=getlab()) ) ) ;
reached = 1;
}
;
ifelprefix: ifprefix statement ELSE
={ if( reached ) branch( $$ = getlab() );
else $$ = NOLAB;
deflab( $1 );
reached = 1;
}
;
whprefix: WHILE LP e RP
={ savebc();
if( !reached ) werror( "loop not entered at top");
if( $3->op == ICON && $3->lval != 0 ) flostat = FLOOP;
deflab( contlab = getlab() );
reached = 1;
brklab = getlab();
if( flostat == FLOOP ) tfree( $3 );
else ecomp( buildtree( CBRANCH, $3, bcon( brklab) ) );
}
;
forprefix: FOR LP .e SM .e SM
={ if( $3 ) ecomp( $3 );
else if( !reached ) werror( "loop not entered at top");
savebc();
contlab = getlab();
brklab = getlab();
deflab( $$ = getlab() );
reached = 1;
if( $5 ) ecomp( buildtree( CBRANCH, $5, bcon( brklab) ) );
else flostat |= FLOOP;
}
;
switchpart: SWITCH LP e RP
={ savebc();
brklab = getlab();
ecomp( buildtree( FORCE, $3, NIL ) );
branch( $$ = getlab() );
swstart();
reached = 0;
}
;
/* EXPRESSIONS */
con_e: { $<intval>$=instruct; stwart=instruct=0; } e
%prec CM
={ $$ = icons( $2 ); instruct=$<intval>1; }
;
.e: e
|
={ $$=0; }
;
elist: e
%prec CM
| elist CM e
={ goto bop; }
;
e: e RELOP e
={
preconf:
if( yychar==RELOP||yychar==EQUOP||yychar==AND||yychar==OR||yychar==ER ){
precplaint:
if( hflag ) werror( "precedence confusion possible: parenthesize!" );
}
bop:
$$ = buildtree( $2, $1, $3 );
}
| e CM e
={ $2 = COMOP;
goto bop;
}
| e DIVOP e
={ goto bop; }
| e PLUS e
={ if(yychar==SHIFTOP) goto precplaint; else goto bop; }
| e MINUS e
={ if(yychar==SHIFTOP ) goto precplaint; else goto bop; }
| e SHIFTOP e
={ if(yychar==PLUS||yychar==MINUS) goto precplaint; else goto bop; }
| e MUL e
={ goto bop; }
| e EQUOP e
={ goto preconf; }
| e AND e
={ if( yychar==RELOP||yychar==EQUOP ) goto preconf; else goto bop; }
| e OR e
={ if(yychar==RELOP||yychar==EQUOP) goto preconf; else goto bop; }
| e ER e
={ if(yychar==RELOP||yychar==EQUOP) goto preconf; else goto bop; }
| e ANDAND e
={ goto bop; }
| e OROR e
={ goto bop; }
| e MUL ASSIGN e
={ abop:
$$ = buildtree( ASG $2, $1, $4 );
}
| e DIVOP ASSIGN e
={ goto abop; }
| e PLUS ASSIGN e
={ goto abop; }
| e MINUS ASSIGN e
={ goto abop; }
| e SHIFTOP ASSIGN e
={ goto abop; }
| e AND ASSIGN e
={ goto abop; }
| e OR ASSIGN e
={ goto abop; }
| e ER ASSIGN e
={ goto abop; }
| e QUEST e COLON e
={ $$=buildtree(QUEST, $1, buildtree( COLON, $3, $5 ) );
}
| e ASOP e
={ werror( "old-fashioned assignment operator" ); goto bop; }
| e ASSIGN e
={ goto bop; }
| term
;
term: term INCOP
={ $$ = buildtree( $2, $1, bcon(1) ); }
| MUL term
={ ubop:
$$ = buildtree( UNARY $1, $2, NIL );
}
| AND term
={ if( ISFTN($2->type) || ISARY($2->type) ){
werror( "& before array or function: ignored" );
$$ = $2;
}
else goto ubop;
}
| MINUS term
={ goto ubop; }
| UNOP term
={
$$ = buildtree( $1, $2, NIL );
}
| INCOP term
={ $$ = buildtree( $1==INCR ? ASG PLUS : ASG MINUS,
$2,
bcon(1) );
}
| SIZEOF term
={ $$ = doszof( $2 ); }
| LP cast_type RP term %prec INCOP
={ $$ = buildtree( CAST, $2, $4 );
$$->left->op = FREE;
$$->op = FREE;
$$ = $$->right;
}
| SIZEOF LP cast_type RP %prec SIZEOF
={ $$ = doszof( $3 ); }
| term LB e RB
={ $$ = buildtree( UNARY MUL, buildtree( PLUS, $1, $3 ), NIL ); }
| funct_idn RP
={ $$=buildtree(UNARY CALL,$1,NIL); }
| funct_idn elist RP
={ $$=buildtree(CALL,$1,$2); }
| term STROP NAME
={ if( $2 == DOT ){
$1 = buildtree( UNARY AND, $1, NIL );
}
idname = $3;
$$ = buildtree( STREF, $1, buildtree( NAME, NIL, NIL ) );
}
| NAME
={ idname = $1;
/* recognize identifiers in initializations */
if( blevel==0 && stab[idname].stype == UNDEF ) {
register NODE *q;
werror( "undeclared initializer name %.8s", stab[idname].sname );
q = block( FREE, NIL, NIL, INT, 0, INT );
q->rval = idname;
defid( q, EXTERN );
}
$$=buildtree(NAME,NIL,NIL);
stab[$1].suse = -lineno;
}
| ICON
={ $$=bcon(0);
$$->lval = lastcon;
$$->rval = NONAME;
if( $1 ) $$->csiz = $$->type = ctype(LONG);
}
| FCON
={ $$=buildtree(FCON,NIL,NIL);
$$->dval = dcon;
}
| STRING
={ $$ = getstr(); /* get string contents */ }
| LP e RP
={ $$=$2; }
;
cast_type: type null_decl
={
$$ = tymerge( $1, $2 );
$$->op = NAME;
$1->op = FREE;
}
;
null_decl: /* empty */
={ $$ = bdty( NAME, NIL, -1 ); }
| LP RP
={ $$ = bdty( UNARY CALL, bdty(NAME,NIL,-1),0); }
| LP null_decl RP LP RP
={ $$ = bdty( UNARY CALL, $2, 0 ); }
| MUL null_decl
={ goto umul; }
| null_decl LB RB
={ goto uary; }
| null_decl LB con_e RB
={ goto bary; }
| LP null_decl RP
={ $$ = $2; }
;
funct_idn: NAME LP
={ if( stab[$1].stype == UNDEF ){
register NODE *q;
q = block( FREE, NIL, NIL, FTN|INT, 0, INT );
q->rval = $1;
defid( q, EXTERN );
}
idname = $1;
$$=buildtree(NAME,NIL,NIL);
stab[idname].suse = -lineno;
}
| term LP
;
%%
NODE *
mkty( t, d, s ) unsigned t; {
return( block( TYPE, NIL, NIL, t, d, s ) );
}
NODE *
bdty( op, p, v ) NODE *p; {
register NODE *q;
q = block( op, p, NIL, INT, 0, INT );
switch( op ){
case UNARY MUL:
case UNARY CALL:
break;
case LB:
q->right = bcon(v);
break;
case NAME:
q->rval = v;
break;
default:
cerror( "bad bdty" );
}
return( q );
}
dstash( n ){ /* put n into the dimension table */
if( curdim >= DIMTABSZ-1 ){
cerror( "dimension table overflow");
}
dimtab[ curdim++ ] = n;
}
savebc() {
if( psavbc > & asavbc[BCSZ-4 ] ){
cerror( "whiles, fors, etc. too deeply nested");
}
*psavbc++ = brklab;
*psavbc++ = contlab;
*psavbc++ = flostat;
*psavbc++ = swx;
flostat = 0;
}
resetbc(mask){
swx = *--psavbc;
flostat = *--psavbc | (flostat&mask);
contlab = *--psavbc;
brklab = *--psavbc;
}
addcase(p) NODE *p; { /* add case to switch */
p = optim( p ); /* change enum to ints */
if( p->op != ICON ){
uerror( "non-constant case expression");
return;
}
if( swp == swtab ){
uerror( "case not in switch");
return;
}
if( swp >= &swtab[SWITSZ] ){
cerror( "switch table overflow");
}
swp->sval = p->lval;
deflab( swp->slab = getlab() );
++swp;
tfree(p);
}
adddef(){ /* add default case to switch */
if( swtab[swx].slab >= 0 ){
uerror( "duplicate default in switch");
return;
}
if( swp == swtab ){
uerror( "default not inside switch");
return;
}
deflab( swtab[swx].slab = getlab() );
}
swstart(){
/* begin a switch block */
if( swp >= &swtab[SWITSZ] ){
cerror( "switch table overflow");
}
swx = swp - swtab;
swp->slab = -1;
++swp;
}
swend(){ /* end a switch block */
register struct sw *swbeg, *p, *q, *r, *r1;
CONSZ temp;
int tempi;
swbeg = &swtab[swx+1];
/* sort */
r1 = swbeg;
r = swp-1;
while( swbeg < r ){
/* bubble largest to end */
for( q=swbeg; q<r; ++q ){
if( q->sval > (q+1)->sval ){
/* swap */
r1 = q+1;
temp = q->sval;
q->sval = r1->sval;
r1->sval = temp;
tempi = q->slab;
q->slab = r1->slab;
r1->slab = tempi;
}
}
r = r1;
r1 = swbeg;
}
/* it is now sorted */
for( p = swbeg+1; p<swp; ++p ){
if( p->sval == (p-1)->sval ){
uerror( "duplicate case in switch, %d", tempi=p->sval );
return;
}
}
genswitch( swbeg-1, swp-swbeg );
swp = swbeg-1;
}
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.